17. MESSAGES Most error messages have an associated error number. By looking up the number in the list below you can obtain additional information about the cause of the error. This information is also available from a self-extracting executable msg.exe, found on the PC-lint distribution diskette, which produces the machine-readable ASCII file msg.txt. For FlexeLint users, the file msg.txt can be found on the FlexeLint Supplementary diskette. Messages numbered 1000 and higher pertain generally to C++. This is summarized in the table below. After a possible 1000 is subtracted off, the remainder lies in the range 0-999. Remainders in the range 1-199 are syntax errors, 200-299 are PC-lint/FlexeLint internal errors and should never occur, 300-399 are fatal errors usually brought about by exceeding some limit, 400-699 are warning messages that indicate that something is likely to be wrong with the program being examined. Remainders in the range 700-899 designate informational messages. These may be errors but they also may represent legitimate programming practices depending upon personal programming style. Remainders in the range 900-999 are called "Elective Notes". They are not automatically output. You may examine the list to see if you wish to be alerted to any of them. C C++ Warning Level Syntax Errors 1 - 199 1001 - 1199 1 Internal Errors 200 - 299 0 Fatal Errors 300 - 399 0 Warnings 400 - 699 1400 - 1699 2 Informational 700 - 899 1700 - 1899 3 Elective Notes 900 - 999 1900 - 1999 4 Glossary A few of the terms used in the commentary below are: argument The actual argument of a function as opposed to a dummy (or formal) parameter of a function (see parameter). arithmetic any of the integral types (see below) plus float, double, and long double. Boolean In general, the word Boolean refers to quantities that can be either true or false. An expression is said to be Boolean (perhaps it would be better to say 'definitely Boolean') if it is of the form: operand op operand where op is a relational (> >= < <=), an equality operator (== !=), logical And (&&) or logical Or (||). A context is said to require a Boolean if it is used in an if or while clause or if it is the 2nd expression of a for clause or if it is an argument to one of the operators: && or ||. An expression needn't be definitely Boolean to be acceptable in a context that requires a Boolean. Any integer or pointer is acceptable. declaration gives properties about an object or function (as opposed to a definition). definition that which allocates space for an object or function (as opposed to a declaration) and which may also indicate properties about the object. There should be only one definition for an object but there may be many declarations. integral a type that has properties similar to integers. These include char, short, int, and long and the unsigned variations of any of these. scalar any of the arithmetic types plus pointers. lvalue is an expression that can be used on the Left hand side of an assignment operator (=). Some contexts require lvalues such as autoincrement (++) and autodecrement (--). macro an abbreviation defined by a #define statement. It may or may not have arguments. member elements of a struct and of a union are called members. module that which is compiled by a compiler in a single independent compilation. It typically includes all the text of a .c (or a .cpp or .cxx, etc.) file plus any text within any #include file(s). parameter A formal parameter of a function as opposed to an actual argument (see argument). Message Parameters Some of the messages are parameterized with one or more of the following italicized names: Char Some character Context Specifies one of several contexts in which an assignment can be made. Can be one of: o assignment -- refers to an explicit assignment operator. o return -- refers to the implied assignment of a return statement. The type of the expression is converted implicitly to the type of the function. o initialization -- refers to the assignment implied by an initialization statement. o arg. no.... -- refers to the implied assignment of an argument in the presence of a prototype. The type of the expression is implicitly converted to the type within a prototype. o arg. 'this' -- refers to the implied argument of a member function call. FileName A filename. Messages containing this parameter can be suppressed with the -efile( ... ) option. Integer Some integer Invocation A function call with argument types. To suppress a message containing an Invocation you need the complete call, not just the function name. For example, the call f(1) could result in Error 1024 parameterized by 'f(int)'. To suppress this message you could use -esym(1024,f(int)). You could also use wild cards as in -esym(1024,f*). Kind A list of control structures. Location A line number followed optionally by a filename (if different from the current) and/or a module name if different from the current. Name A string, usually an identifier, that can be suppressed with a -esym but not with -elibsym. String A sequence of characters identified further in the message description. Symbol The name of a user identifier referring to a C or C++ object such as variable, function, structure, etc. Messages containing this parameter can be suppressed with the -esym( ... ) option. For C++, if Symbol is the name of a function the full function signature (including parameters) is given. Error suppression with -esym does not require (nor want) the parameters. Type A type or a top type base is provided. A top type base is one of pointer, function, array, struct, union, or enum. TypeDiff specifies the way in which one type differs from another. Because of type qualification, function prototypes, and type compounding, it may not be obvious how two types differ. Also, see the -etd option to inhibit errors based on type differences. TypeDiff can be one or more of: o basic -- The two types differ in some fundamental way such as double versus int. o count -- Two function types differ in the number of arguments. o ellipsis -- Two function types differ in that one is prototyped using an ellipsis and the other is not prototyped. See Section 15. o incomplete -- At least one of the types is only partially specified such as an array without a dimension or a function without a prototype. o nominal -- The types are nominally different but are otherwise the same. For example, int versus long where these are the same size or double versus long double where these are the same size. The two types are either both integral or both float or are functions that return types or have arguments that differ nominally. If long is the same size as int then unsigned long will differ from int both as nominal and as signed/unsigned. If not the same size, then the difference is precision. o origin -- The types are not actually different but have different origins. For example a struct is defined in two separate modules rather than in one header file. If for some reason you want to do this then use the option -etd(origin). o precision -- Two arithmetic types differ in their precision such as int vs. long where these are different sizes. o promotion -- Two function types differ in that one is prototyped with a char, short or float type and the other is not prototyped. o ptrs to... -- Pointers point to different types, some TypeDiff code follows. o ptrs to incompatible types -- Pointers point to types, which in turn differ in precision, count, size, ellipsis or promotion. o qualification -- Qualifiers such as const, volatile, etc. are inconsistent. o signed/unsigned -- The types differ in that one is a signed integral type and the other is unsigned of the same size, or they are both functions that return types that differ in this way, or they are both pointers to types that differ in this way. o size -- Two arrays differ in array dimension. o strong -- two types differ in that one is strong and the other is not the same strong type. o void/nonvoid -- The two types differ in that one is void and the other is not or, more frequently, they are both functions returning types that differ in this respect or pointers to types that differ in this respect. o enum/enum-- One type is an enum. The other type is a different enum. o int/enum-- One type is an enum and the other is an int. o Type = Type -- The two types in an assignment of some kind differ in some basic way and no more information is available. o Type vs. Type -- The two types differ in some basic way and no more information is available. 17.1 C Syntax Errors 1 Unclosed Comment (Location) -- End of file was reached with an open comment still unclosed. The Location of the open comment is shown. 2 Unclosed Quote -- An end of line was reached and a matching quote character (single or double) to an earlier quote character on the same line was not found. 3 #else without a #if -- A #else was encountered not in the scope of a #if, #ifdef or #ifndef. 4 Too many #if levels -- An internal limit was reached on the level of nesting of #if statements (including #ifdef and #ifndef). 5 Too many #endif's -- A #endif was encountered not in the scope of a #if or #ifdef or #ifndef. 6 Stack Overflow -- One of the built-in non-extendable stacks has been overextended. The possibilities are too many nested #if statements, #includes statements (including all recursive #include statements), static blocks (bounded by braces) or #define replacements. 7 Unable to open include file: FileName -- FileName is the name of the include file, which could not be opened. See also flag fdi (See Section 5.), option -i... ( See Section 5.) and Section 13.2.1 INCLUDE Environment Variable. 8 Unclosed #if (Location) -- A #if (or #ifdef or #ifndef) was encountered without a corresponding #endif. Location is the location of the #if. 9 Too many #else's in #if (Location) -- A given #if contained a #else, which in turn was followed by either another #else or a #elif. The error message gives the line of the #if statement that started the conditional that contained the aberration. 10 Expecting 'String' -- String is the expected token. The expected token could not be found. This is commonly given when certain reserved words are not recognized. int __interrupt f(); will receive an Expecting ';' message at the f because it thinks you just declared __interrupt. The cure is to establish a new reserved word with +rw(__interrupt). Also, make sure you are using the correct compiler options file. See also Section 15.10 Strange Compilers. 11 Excessive Size -- The filename specified on a #include line had a length that exceeded FILENAME_MAX characters. 12 Need < or " -- After a #include is detected and after macro substitution is performed, a file specification of the form or "filename" is expected. 13 Bad type -- A type adjective such as long, unsigned, etc. cannot be applied to the type, which follows. 14 Symbol 'Symbol' previously defined (Location) -- The named object has been defined a second time. The location of the previous definition is provided. If this is a tentative definition (no initializer) then the message can be suppressed with the +fmd flag. (Section 5.5 Flag Options). 15 Symbol 'Symbol' redeclared (TypeDiff) (Location) -- The named symbol has been previously declared or defined in some other module (location given) with a type different from the type given by the declaration at the current location. The parameter TypeDiff provides further infor mation on how the types differ (see Glossary in Chapter 17. MESSAGES.). 16 Unrecognized name -- A # directive is not followed by a recognizable word. If this is not an error, use the +ppw option. (Section 5.7 Other Options). 17 Unrecognized name -- A non-parameter is being declared where only parameters should be. 18 Symbol 'Symbol' redeclared (TypeDiff) conflicts with Location -- A symbol is being redeclared. The parameter TypeDiff provides further information on how the types differ (see Glossary Chapter 17. MESSAGES.). Location is the location of the previous definition. 19 Useless Declaration -- A type appeared by itself without an associated variable, and the type was not a struct and not a union and not an enum. A double semi-colon can cause this as in: int x;; 20 Illegal use of = -- A function declaration was followed by an = sign. 21 Expected { -- An initializer for an indefinite size array must begin with a left brace. 22 Illegal operator -- A unary operator was found following an operand and the operator is not a post operator. 23 Expected colon -- A ? operator was encountered but this was not followed by a : as was expected. 24 Expected an expression, found 'String' -- An operator was found at the start of an expression but it was not a unary operator. 25 Illegal constant -- Too many characters were encountered in a character constant (a constant bounded by ' marks). 26 Expected an expression, found 'String' -- An expression was not found where one was expected. The unexpected token is placed in the message. 27 Illegal character (0xhh) -- An illegal character was found in the source code. The hex code is provided in the message. A blank is assumed. If you are using strange characters in identifier names you will get this message for which you may use the -ident option. ( See Section 5.) 28 Redefinition of symbol 'Symbol' Location -- The identifier preceding a colon was previously declared at the Location given as not being a label. 30 Expected a constant -- A constant was expected but not obtained. This could be following a case keyword, an array dimension, bit field length, enumeration value, #if expression, etc. 31 Redefinition of symbol 'Symbol' conflicts with Location -- A data object or function previously defined in this module is being redefined. 32 Field size (member 'Symbol') should not be zero -- The length of a field was given as non-positive, (0 or negative). 33 Illegal constant -- A constant was badly formed as when an octal constant contains one of the digits 8 or 9. 34 Non-constant initializer -- A non-constant initializer was found for a static data item. 35 Initializer has side-effects -- An initializer with side effects was found for a static data item. 36 Redefining the storage class of symbol 'Symbol' conflicts with Location -- An object's storage class is being changed. 37 Value of enumerator 'Symbol' inconsistent (conflicts with Location) -- An enumerator was inconsistently valued. 38 Offset of symbol 'Symbol' inconsistent (Location) -- A member of a class or struct appears in a different position (offset from the start of the structure) than an earlier declaration. This could be caused by array dimensions changing from one module to another. 39 Redefinition of symbol 'Symbol' conflicts with Location -- A struct or union is being redefined. 40 Undeclared identifier 'Name' -- Within an expression, an identifier was encountered that had not previously been declared and was not followed by a left parenthesis. Name is the name of the identifier. 41 Redefinition of symbol 'Symbol' -- A parameter of either a function or a macro is being repeated. 42 Expected a statement -- A statement was expected but a token was encountered that could not possibly begin a statement. 43 Vacuous type for variable 'Symbol' -- A vacuous type was found such as the void type in a context that expected substance. 44 Need a switch -- A case or default statement occurred outside a switch. 45 Bad use of register -- A variable is declared as a register but its type is inconsistent with it being a register (such as a function). 46 Field type should be int -- Bit fields in a structure should be typed unsigned or int. If your compiler allows other kinds of objects, such as char, then simply suppress this message. 47 Bad type -- Unary minus requires an arithmetic operand. 48 Bad type -- Unary * or the left hand side of the ptr (->) operator requires a pointer operand. 49 Expected a type -- Only types are allowed within prototypes. A prototype is a function declaration with a sequence of types within parentheses. The processor is at a state where it has detected at least one type within parentheses and so is expecting more types or a closing right parenthesis. 50 Attempted to take the address of a non-lvalue -- Unary & operator requires an lvalue (a value suitable for placement on the left hand side of an assignment operator). 51 Expected integral type -- Unary ~ expects an integral type (signed or unsigned char, short, int, or long). 52 Expected an lvalue -- autodecrement (--) and autoincrement (++) operators require an lvalue (a value suitable for placement on the left hand side of an assignment operator). Remember that casts do not normally produce lvalues. Thus ++(char *)p; is illegal according to the ANSI standard. This construct is allowed by some compilers and is allowed if you use the +fpc option (Pointer Casts are lvalues). (See Section 5.) 53 Expected a scalar -- Autodecrement (--) and autoincrement (++) operators may only be applied to scalars (arithmetics and pointers) or to objects for which these operators have been defined. 54 Division by 0 -- The constant 0 was used on the right hand side of the division operator (/) or the remainder operator (%). 55 Bad type -- The context requires a scalar, function, array, or struct (unless -fsa). 56 Bad type -- Add/subtract operator requires scalar types and pointers may not be added to pointers. 57 Bad type -- Bit operators ( &, | and ^ ) require integral arguments. 58 Bad type -- Bad arguments were given to a relational operator; these always require two scalars and pointers can't be compared with integers (unless constant 0). 59 Bad type -- The amount by which an item can be shifted must be integral. 60 Bad type -- The value to be shifted must be integral. 61 Bad type -- The context requires a Boolean. Booleans must be some form of arithmetic or pointer. 62 Incompatible types (TypeDiff) for operator ':' -- The 2nd and 3rd arguments to ? : must be compatible types. 63 Expected an lvalue -- Assignment expects its first operand to be an lvalue. Please note that a cast removes the lvaluedness of an expression. But see also flag +fpc in Section 5.5 Flag Options. 64 Type mismatch (Context) (TypeDiff) -- There was a mismatch in types across an assignment (or implied assignment, see Context). TypeDiff specifies the type difference. See options -epn, -eps, -epu, -epp (Section 5.2 Error Inhibition Options) to suppress this message when assigning some kinds of pointers. 65 Expected a member name -- After a dot (.) or pointer (->) operator a member name should appear. 66 Bad type -- A void type was employed where it is not permitted. If a void type is placed in a prototype then it must be the only type within a prototype. (See error number 49.) 67 Can't cast from Type to Type -- Attempt to cast a non-scalar to an integral. 68 Can't cast from Type to Type -- Attempt to cast a non-arithmetic to a float. 69 Can't cast from Type to Type -- Bad conversion involving incompatible structures or a structure and some other object. 70 Can't cast from Type to Type -- Attempt to cast to a pointer from an unusual type (non-integral). 71 Can't cast from Type to Type -- Attempt to cast to a type that does not allow conversions. 72 Bad option 'String' -- Was not able to interpret an option. The option is given in String. 73 Bad left operand -- The cursor is positioned at or just beyond either an -> or a . operator. These operators expect an expression primary on their left. Please enclose any complex expression in this position within parentheses. 74 Address of Register -- An attempt was made to apply the address (&) operator to a variable whose storage class was given as register. 75 Too late to change sizes (option 'String') -- The size option was given after all or part of a module was processed. Make sure that any option to reset sizes of objects be done at the beginning of the first module processed or on the command line before any module is processed. 76 can't open file String -- String is the name of the file. The named file could not be opened for output. The file was destined to become a PC-lint/FlexeLint object module. 77 Address of bit-field cannot be taken -- The address of a bit-field cannot be taken. The rules of C only allow for taking the address of a whole byte (a whole char). 78 Symbol 'Symbol' typedef'ed at Location used in expression -- The named symbol was defined in a typedef statement and is therefore considered a type. It was subsequently found in a context where an expression was expected. 79 Bad type for % operator -- The % operator should be used with some form of integer. 80 this use of ellipsis is not strictly ANSI -- The ellipsis should be used in a prototype only after a sequence of types not after a sequence of identifiers. Some compilers support this extension. If you want to use this feature suppress this message. 81 struct/union not permitted in equality comparison -- Two struct's or union's are being compared with one of == or !=. This is not permitted by the ANSI standard. If your compiler supports this, suppress this message. 82 return ; illegal with void function -- The ANSI standard does not allow an expression form of the return statement with a void function. If you are trying to cast to void as in return (void)f(); and your compiler allows it, suppress this message. 83 Incompatible pointer types with subtraction -- Two pointers being subtracted have indirect types which differ. You can get PC-lint/FlexeLint to ignore slight differences in the pointers by employing one or more of the -ep... options described in Section 5.2 Error Inhibition Options. 84 sizeof object is zero or object is undefined -- A sizeof returned a 0 value. This could happen if the object were undefined or incompletely defined. Make sure a complete definition of the object is in scope when you use sizeof. 85 Array 'Symbol' has dimension 0 -- An array (named Symbol) was declared without a dimension in a context that required a non-zero dimension. 86 Structure 'Symbol' has no data elements -- A structure was declared (in a C module) that had no data members. Though legal in C++ this is not legal C. 87 Expression too complicated for #ifdef or #ifndef -- By the rules of C there should be only a single identifier following a #ifdef or a #ifndef. You may also supply a validly constructed C (or C++) comment. 88 Symbol 'Symbol' is an array of empty elements -- An array was declared (in a C module) whose elements were each of 0 length. Though legal in C++ this is not permitted C. 90 Option 'String' is only appropriate within a lint comment -- The indicated option is not appropriate at the command or the .lnt level. For example if -unreachable is given on the command line you will get this message. 91 Line exceeds Integer characters (use +linebuf) -- A line read from one of the input files is longer than anticipated. By default the line buffer size is 600 characters. Each time you use the +linebuf option you can double this size. The size can be doubled ad infinitum. 92 Negative array dimension or bit field length (Integer) -- A negative array dimension or bit field length is not permitted. 93 New-line is not permitted within string arguments to macros -- A macro invocation contains a string that is split across more than one line. For example: A( "Hello World" ); will trigger this message. Some compilers accept this construct and you can suppress this message with -e93 if this is your current practice. But it is more portable to place the string constant on one line. Thus A( "Hello World" ); would be better. 101 Expected an identifier -- While processing a function declarator, a parameter specifier was encountered that was not an identifier, whereas a prior parameter was specified as an identifier. This is mixing old-style function declarations with the new-style and is not permitted. For example void f(n,int m) will elicit this message. 102 Illegal parameter specification -- Within a function declarator, a parameter must be specified as either an identifier or as a type followed by a declarator. 103 Unexpected declaration -- After a prototype, only a comma, semi-colon, right parenthesis or a left brace may occur. This error could occur if you have omitted a terminating character after a declaration or if you are mixing old-style parameter declarations with new-style prototypes. 104 Conflicting types -- Two consecutive conflicting types were found such as int followed by double. Remove one of the types! 105 Conflicting modifiers -- Two consecutive conflicting modifiers were found such as far followed by near. Remove one of the modifiers! 106 Illegal constant -- A string constant was found within a preprocessor expression as in #if ABC == "abc" Such expressions should be integral expressions. 107 Label 'Symbol' (Location) not defined -- The Symbol at the given Location appeared in a goto but there was no corresponding label. 108 Invalid context -- A continue or break statement was encountered without an appropriate surrounding context such as a for, while, or do loop or, for the break statement only, a surrounding switch statement. 110 Attempt to assign to void -- An attempt was made to assign a value to an object designated (possibly through a pointer) as void. 111 Assignment to const object -- An object declared as const was assigned a value. This could arise via indirection. For example, if p is a pointer to a const int then assigning to *p will raise this error. 113 Inconsistent enum declaration -- The sequence of members within an enum (or their values) is inconsistent with that of another enum (usually in some other module) having the same name. 114 Inconsistent structure declaration for tag 'Symbol' -- The sequence of members within a structure (or union) is inconsistent with another structure (usually in some other module) having the same name. 115 Struct/union not defined -- A reference to a structure or a union was made that required a definition and there is no definition in scope. For example, a reference to p->a where p is a pointer to a struct that had not yet been defined in the current module. 116 Inappropriate storage class -- A storage class other than register was given in a section of code that is dedicated to declaring parameters. The section is that part of a function preceding the first left brace. 117 Inappropriate storage class -- A storage class was provided outside any function that indicated either auto or register. Such storage classes are appropriate only within functions. 118 Too few arguments for prototype -- The number of arguments provided for a function was less than the number indicated by a prototype in scope. 119 Too many arguments for prototype -- The number of arguments provided for a function was greater than the number indicated by a prototype in scope. 122 Digit (Char) too large for radix -- The indicated character was found in a constant beginning with zero. For example, 08 is accepted by some compilers to represent 8 but it should be 010 or plain 8. 123 Macro 'Symbol' defined with arguments at Location this is just a warning -- The name of a macro defined with arguments was subsequently used without a following '('. This is legal but may be an oversight. It is not uncommon to suppress this message (with -e123), because some compilers allow, for example, the macro max() to coexist with a variable max. ( See Section 15.). 124 Pointer to void not allowed -- A pointer to void was used in a context that does not permit void. This includes subtraction, addition and the relationals (> >= < <=). 125 Too many storage class specifiers -- More than one storage class specifier (static, extern, typedef, register or auto) was found. Only one is permitted. 126 Inconsistent structure definition 'Symbol' -- The named structure (or union or enum) was inconsistently defined across modules. The inconsistency was recognized while processing a lint object module. Line number information was not available with this message. Alter the structures so that the member information is consistent. 127 Illegal constant -- An empty character constant ('') was found. 128 Pointer to function not allowed -- A pointer to a function was found in an arithmetic context such as subtraction, addition, or one of the relationals (> >= < <=). 129 declaration expected, identifier 'Symbol' ignored -- In a context in which a declaration was expected an identifier was found. Moreover, the identifier was not followed by '(' or a '[' 130 Expected integral type -- The expression in a switch statement must be some variation of an int (possibly long or unsigned) or an enum. 131 syntax error in call of macro 'Symbol' at location Location -- This message is issued when a macro with arguments (function-like macro) is invoked and an incorrect number of arguments is provided. Location is the location of the start of the macro call. This can be useful because an errant macro call can extend over many lines. 132 Expected function definition -- A function declaration with identifiers between parentheses is the start of an old-style function definition (K&R style). This is normally followed by optional declarations and a left brace to signal the start of the function body. Either replace the identifier(s) with type(s) or complete the function with a function body. 133 Too many initializers for aggregate -- In a brace-enclosed initializer, there are more items than there are elements of the aggregate. 134 Missing initializer -- An initializer was expected but only a comma was present. 135 comma assumed in initializer -- A comma was missing between two initializers. For example: int a[2][2] = { { 1, 2 } { 3, 4 } }; is missing a comma after the first right brace (}). 136 Illegal macro name -- The ANSI standard restricts the use of certain names as macros. defined is on the restricted list. 137 constant 'Symbol' used twice within switch -- The indicated constant was used twice as a case within a switch statement. Currently only enumerated types are checked for repeated occurrence. 138 Can't add parent 'Symbol' to strong type String; creates loop -- An attempt was made to add a strong type parent to a typedef type. The attempt is either explicit (with the -strong option) or implicit with the use of a typedef to a known strong type. This attempt would have caused a loop in the strong parent relationship. Such loops are simply not tolerated. 139 Can't take sizeof function -- There is an attempt to take the sizeof a function. 140 Type appears after modifier -- Microsoft modifiers such as far, _near, __huge, _pascal, etc. etc. modify the declarator to its immediate right. It therefore should not appear before the type. For example, you should write int pascal f(void); rather than pascal int f(void);. Note that const and volatile differ from the Microsoft modifiers. They may appear before or after the type. After reporting the error an attempt is made to process the modifiers as the programmer probably intended. See also the +fem flag in Section 5.5 Flag Options. 141 The following option has too many elements: 'String' -- The indicated option (given by 'String') is too big. It most likely consists of an itemized list that has too many items. You should decompose the large option into two or more smaller options that in sum are equivalent to the one large option. 144 Non-existent return value for symbol 'Symbol', compare with Location -- An attempt was made to use a non-existent return value of the named function (identified by Symbol). It was previously decided that the function did not return a value or was declared with void. 145 Type expected before operator, void assumed -- In a context in which a type is expected no type is found. Rather, an operator '*' or '&' was encountered. The keyword void was assumed to have preceded this operator. 146 Assuming a binary constant -- A constant of the form 0b... was encountered. This was taken to be a binary constant. For example, 0b100 represents the value 4. If your compiler supports binary constants you may suppress this message. 147 sizeof takes just one argument -- An expression of the form sizeof(a,b) was detected. A second argument is non standard and has been used by some compilers to denote an option to the sizeof operator. If your compiler has a use for the second argument then suppress this message. 148 member 'Symbol' previously declared at Location -- The indicated member was previously declared within the same structure or union. Although a redeclaration of a function may appear benign it is just not permitted by the rules of the language. One of the declarations should be removed. 149 C++ construct 'String' found in C code -- An illegal construct was found in C code. It looked as though it might be suitable for C++. The quoted string identifies the construct further. 150 Token 'String' unexpected String -- An unexpected token was encountered. The action taken, if any, is identified by the second message parameter. 151 Token 'Name' inconsistent with abstract type -- In a context in which an abstract type is allowed such as within a cast or after a sizeof, and after starting to parse the abstract type, an identifier was found. For example: x = (int y) z; 152 Lob base file 'file name' missing -- The indicated file has been specified as the base of lob production via the option -lobbase(). On output, this message is given if the lob base is missing. The situation is correctable by simply producing the missing lob output. This will not be a problem given the appropriate dependencies in the make file. On input, the most likely cause of this message is an out-of-date base file. A hash code within the lob file being read, did not match a similar code already embedded within the base. The input lob file should be considered in error and should be regenerated. See Chapter 7. 153 Could not create temporary file -- This message is produced when generating a lob output file based upon some lob base file. When the lob file is produced, it is first written to a temporary. The temporary is generated by the C library function tmpnam(). 154 Could not evaluate type 'String', int assumed -- String in the message is the second argument to either a printf_code option or a scanf_code option. When used, it was to be evaluated as a type. Unfortunately the type could not be identified. 155 Ignoring {...} sequence within an expression, 0 assumed -- A braced sequence within an expression is a non-standard extension of some compilers (in particular GCC). Internally, we treat such a braced sequence as the equivalent of a constant 0. This means that we may be able to quietly lint such constructions if you merely suppress the message. 17.2 Internal Errors 200-299 Some inconsistency or contradiction was discovered in the PC-lint/FlexeLint system. This may or may not be the result of a user error. This inconsistency should be brought to the attention of Gimpel Software. 17.3 Fatal Errors Errors in this category are normally fatal and suppressing the error is normally impossible. However, those errors marked with an asterisk(*) can be suppressed and processing will be continued. For example -e306 will allow reprocessing of modules. 301 Stack overflow -- There was a stack overflow while processing declarations. Approximately 50 nested declarators were found. For example, if a '/' followed by 50 consecutive '*'s were to introduce a box-like comment and if the '/' were omitted, then this message would be produced. 302 Exceeded Available Memory -- Main memory has been exhausted. 303 String too long (try +macros) -- A single #define definition or macro invocation exceeded an internal limit (of 4096 characters). As the diagnostic indicates the problem can be corrected with an option. 304 Corrupt object file, code Integer, symbol=String -- A PC-lint/FlexeLint object file is apparently corrupted. Please delete the object module and recreate it using the -oo option. See Section 7. The special code identifier number as well as a list of symbol names are optionally suffixed to the message as an aid in diagnosing the problem by technical support. 305 Unable to open module 'file name' -- file name is the name of the file. The named module could not be opened for reading. Perhaps you misspelled the name. 306* Previously encountered module 'FileName' -- FileName is the name of the module. The named module was previously encountered. This is probably a user blunder. 307 Can't open indirect file 'FileName' -- FileName is the name of the indirect file. The named indirect file (ending in .lnt) could not be opened for reading. 308 Can't write to standard out -- stdout was found to equal NULL. This is most unusual. 309* #error ... -- The #error directive was encountered. The ellipsis reflects the original line. Normally processing is terminated at this point. If you set the fce (continue on #error) flag, processing will continue. 310 Declaration too long: 'String...' -- A single declaration was found to be too long for an internal buffer (about 2000 characters). This occurred when attempting to write out the declaration using the -o... option. The first 30 characters of the declaration is given in String. Typically this is caused by a very long struct whose substructures, if any, are untagged. First identify the declaration that is causing the difficulty. If a struct or union, assign a tag to any unnamed substructures or subunion. A typedef can also be used to reduce the size of such a declaration. 312 Lint Object Module has obsolete or foreign version id -- A lint object module was produced with a prior or different version of PC-lint/FlexeLint. Delete the.lob file and recreate it using your new version of PC-lint/FlexeLint. 313 Too many files -- The number of files that PC-lint/FlexeLint can process has exceeded an internal limit. The FlexeLint user may recompile his system to increase this limit. Look for symbol FSETLEN in custom.h. Currently, the number of files is limited to 6400. 314* Previously used .lnt file: FileName -- The indirect file named was previously encountered. If this was not an accident, you may suppress this message. 315 Exceeded message limit (see -limit) -- The maximum number of messages was exceeded. Normally there is no limit unless one is imposed by the -limit(n) option. ( See Section 5.) 316 Error while writing to file "file name" -- The given file could not be opened for output. 321 Declaration stack overflow -- An overflow occurred in the stack used to contain array, pointer, function or reference modifiers when processing a declarator. 322* Unable to open include file FileName -- FileName is the name of the include file, which could not be opened. Directory search is controlled by options: -i (See Section 5.), +fdi (Section 5.5 Flag Options) and the INCLUDE environment variable. This is a suppressible fatal message. If option -e322 is used, Error message 7 will kick in. A diagnostic will be issued but processing will continue. 323 Token String too long -- In attempting to save a token for later reuse, a fixed size buffer was exceeded (governed by the size M_TOKEN). 324 Too many symbols Integer -- Too many symbols were encountered. An internal limit was reached. 325 Cannot re-open file 'file name' -- In the case of a large number of nested includes, files in the outer fringe need to be closed before new ones are opened. These outer files then need to be re-opened. An error occurred when attempting to re-open such a file. 17.4 C Warning Messages 401 symbol 'Symbol' not previously declared static at Location -- The indicated Symbol declared static was previously declared without the static storage class. This is technically a violation of the ANSI standard. Some compilers will accept this situation without complaint and regard the Symbol as static. 402 static function 'Symbol' (Location) not defined -- The named Symbol was declared as a static function in the current module and was referenced but was not defined (in the module). 403 static symbol 'Symbol' has unusual type modifier -- Some type modifiers such as _export are inconsistent with the static storage class. 404 struct not completed within file 'FileName' -- A struct (or union or enum) definition was started within a header file but was not completed within the same header file. 405 #if not closed off within file 'FileName' -- An #if construct was begun within a header file (name given) but was not completed within that header file. Was this intentional? 406 Comment not closed off within file 'FileName' -- A comment was begun within a header file (name given) but was not completed within that header file. Was this intentional? 407 Inconsistent use of tag 'Symbol' conflicts with Location -- A tag specified as a union, struct or enum was respecified as being one of the other two in the same module. For example: struct tag *p; union tag *q; will elicit this message. 408 Type mismatch with switch expression -- The expression within a case does not agree exactly with the type within the switch expression. For example, an enumerated type is matched against an int. 409 Expecting a pointer or array -- An expression of the form i[...] was encountered where i is an integral expression. This could be legitimate depending on the subscript operand. For example, if i is an int and a is an array then i[a] is legitimate but unusual. If this is your coding style, suppress this message. 410 size_t not what was expected from fzl and/or fzu, using 'Type' -- This warning is issued if you had previously attempted to set the type of sizeof by use of the options +fzl, -fzl, or -fzu, and a later size_t declaration contradicts the setting. This usually means you are attempting to lint programs for another system using header files for your own system. If this is the case we suggest you create a directory housing header files for that foreign system, alter size_t within that directory, and lint using that directory. 411 ptrdiff_t not what was expected from fdl option, using 'Type' -- This warning is issued if you had previously attempted to set the type of pointer differences by use of the fdl option and a later ptrdiff_t declaration contradicts the setting. See suggestion in Error Message 410. 412 Ambiguous format specifier '%X' -- The format specifier %X when used with one of the scanf family, is ambiguous. With Microsoft C it means %lx whereas in ANSI C it has the meaning of %x. This ambiguous format specification has no place in any serious C program and should be replaced by one of the above. 413 Likely use of null pointer 'Symbol' in [left/right] argument to operator 'String' Reference -- From information gleaned from earlier statements, it appears certain that a null pointer (a pointer whose value is 0) has been used in a context where null pointers are inappropriate. These include: Unary *, pointer increment (++) or decrement(--), addition of pointer to numeric, and subtraction of two pointers. In the case of binary operators, one of the words 'left' or 'right' is used to designate which operand is null. Symbol identifies the pointer variable that may be null. See also messages 613 and 794, and Section 9.2 Value Tracking. 414 Possible division by 0 -- The second argument to either the division operator (/) or the modulus operator (%) may be zero. Information is taken from earlier statements including assignments, initialization and tests. See Section 9. 415 access of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer was accessed. String designates the operator. The parameter 'Integer' gives some idea how far out of bounds the pointer may be. It is measured in units given by the size of the pointed to object. The value is relative to the last item of good data and therefore should always be greater than zero. For example: int a[10]; a[10] = 0; results in an overflow message containing the phrase '1 beyond end of data'. See Section 9. 416 creation of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer was created. See message 415 for a description of the parameters Integer and String. For example: int a[10]; ... f( a + 11 ); Here, an illicit pointer value is created and is flagged as such by PC-lint/FlexeLint. Note that the pointer a+10 is not considered by PC-lint/FlexeLint to be the creation of an out-of-bounds pointer. This is because ANSI C explicitly allows pointing just beyond an array. Access through a+10, however, as in *(a+10) or the more familiar a[10], would be considered erroneous but in that case message 415 would be issued. See Section 9. 417 integral constant 'String' longer than long long int -- The longest possible integer is by default 8 bytes (see the +fll flag and then the -sll# option). An integral constant was found to be even larger than such a quantity. For example: 0xFFFF0000FFFF0000F. String is the token in error. 418 Passing null pointer to function 'Symbol', Context Reference -- A NULL pointer is being passed to a function identified by Symbol. The argument in question is given by Context. The function is either a library function designed not to receive a NULL pointer or a user function dubbed so via the option -function. See Section 10.1 Function Mimicry (function) and Section 10.2.1 Possible Semantics. 419 Apparent data overrun for function 'Symbol', argument Integer exceeds argument Integer -- This message is for data transfer functions such as memcpy, strcpy, fgets, etc. when the size indicated by the first cited argument (or arguments) exceeds the size of the buffer area cited by the second. The message may also be issued for user functions via the -function option. See Section 10.1 Function Mimicry (function) and Section 10.2.1 Possible Semantics. 420 Apparent access beyond array for function 'Symbol', argument Integer exceeds Integer Reference -- This message is issued for several library functions (such as fwrite, memcmp, etc.) wherein there is an apparent attempt to access more data than exist. For example, if the length of data specified in the fwrite call exceeds the size of the data specified. The function is specified by Symbol and the arguments are identified by argument number. See also Section 10.1 Function Mimicry (function) and Section 10.2.1 Possible Semantics. 421 Caution -- function 'Symbol' is considered dangerous -- This message is issued (by default) for the built-in function gets. This function is considered dangerous because there is no mechanism to ensure that the buffer provided as first argument will not overflow. A well known computer virus (technically a worm) was created based on this defect. Through the -function option, the user may designate other functions as dangerous. 422 Passing to function 'Symbol' a negative value (Integer), Context Reference -- An integral value that appears to be negative is being passed to a function that is expecting only positive values for a particular argument. The message contains the name of the function (Symbol), the questionable value (Integer) and the argument number (Context). The function may be a standard library function designed to accept only positive values such as malloc or memcpy (third argument), or may have been identified by the user as such through the -function or -sem options. The negative integral value may in fact be unsigned. Thus: void *malloc( unsigned ); void f() { int n = -1; int *p; p = malloc(n); // Warning 422 p = malloc( (unsigned) n ); // Warning 422 } will result in the warnings indicated. Note that casting the expression does not inhibit the warning. There is a slight difference in behavior on 32-bit systems versus 16-bit systems. If long is the same size as int (as in 32-bit systems) the warning is issued based upon the sign bit. If long is larger than an int (as is true on typical 16-bit systems) the warning is issued if the value was a converted negative as in the examples above. It is not issued if an unsigned int has the high-order bit set. This is because it is not unreasonable to malloc more that 32,176 bytes in a 16-bit system. 423 Creation of memory leak in assignment to variable 'Symbol' -- An assignment was made to a pointer variable (designated by Symbol), which appeared to already be holding the address of an allocated object, which had not been freed. The allocation of memory, which is not freed, is considered a memory leak. 424 Inappropriate deallocation (Name1) for 'Name2' data. -- This message indicates that a deallocation (free(), delete, or delete[]) as specified by Name1 is inappropriate for the data being freed. [12, Item 5] The kind of data (specified by Name2) is one or more of: malloc, new, new[], static, auto, member, modified or constant. These have the meanings as described below: Malloc data is data obtained from a call to malloc, calloc or realloc. new and new[] data is data derived from calls to new. Static data is either static data within a function or external data. auto data is non-static data in a function. Member data is a component of a structure (and hence can't be independently freed). modified data is the result of applying pointer arithmetic to some other pointer. E.g. p = malloc(100); free( p+1 ); // warning p+1 is considered modified. constant data is the result of casting a constant to a pointer. E.g. int *p = (int *) Ox80002; free(p); // warning 425 'Message' in processing semantic 'String' at token 'String' -- This warning is issued when a syntax error is encountered while processing a semantic option (-sem). The 'Message' depends upon the error. The first 'String' represents the portion of the semantic being processed. The second 'String' denotes the token being scanned when the error is first noticed. 426 Call to function 'Symbol' violates semantic 'String' -- This Warning message is issued when a user semantic (as defined by -sem) is violated. 'String' is the subportion of the semantic that was violated. For example: //lint -sem( f, 1n > 10 && 2n > 10 ) void f( int, int ); ... f( 2, 20 ); results in the message: Call to function 'f(int, int)' violates semantic '(1n>10)' 427 // comment terminates in \ -- A one-line comment terminates in the back-slash escape sequence. This means that the next line will be absorbed in the comment (by a standards-conforming compiler -- not all compilers do the absorption, so beware). It is much safer to end the line with something other than a back-slash. Simply tacking on a period will do. If you really intend the next line to be a comment, the line should be started with its own double slash (//). 428 negative subscript (Integer) in operator 'String' -- A negative integer was added to an array or to a pointer to an allocated area (allocated by malloc, operator new, etc.) This message is not given for pointers whose origin is unknown since a negative subscript is, in general, legal. The addition could have occurred as part of a subscript operation or as part of a pointer arithmetic operation. The operator is denoted by String. The value of the integer is given by Integer. 429 Custodial pointer 'Symbol' (Location) has not been freed or returned -- A pointer of auto storage class was allocated storage, which was neither freed nor returned to the caller. This represents a "memory leak". A pointer is considered custodial if it uniquely points to the storage area. It is not considered custodial if it has been copied. Thus: int *p = new int[20]; // p is a custodial pointer int *q = p; // p is no longer custodial p = new int[20]; // p again becomes custodial q = p + 0; // p remains custodial Here p does not lose its custodial property by merely participating in an arithmetic operation. A pointer can lose its custodial property by passing the pointer to a function. If the parameter of the function is typed pointer to const or if the function is a library function, that assumption is not made. For example p = malloc(10); strcpy (p, "hello"); Then p still has custody of storage allocated. It is possible to indicate via semantic options that a function will take custody of a pointer. See custodial(i) in Section 10.2.1 Possible Semantics. 430 Character '@', taken to specify variable location, is not standard C/C++ -- Many compilers for embedded systems have a declaration syntax that specifies a location in place of an initial value for a variable. For example: int x @0x2000; specifies that variable x is actually location 0x2000. This message is a reminder that this syntax is non-standard (although quite common). If you are using this syntax on purpose, suppress this message. 432 Suspicious argument to malloc -- The following pattern was detected: malloc( strlen(e+1) ) where e is some expression. This is suspicious because it closely resembles the commonly used pattern: malloc( strlen(e)+1 ) If you really intended to use the first pattern then an equivalent expression that will not raise this error is: malloc( strlen(e)-1 ) 433 Allocated area not large enough for pointer -- An allocation was assigned to a pointer whose reach extends beyond the area that was allocated. This would usually happen only with library allocation routines such as malloc and calloc. For example: int *p = malloc(1); This message is also provided for user-declared allocation functions. For example, if a user's own allocation function is provided with the following semantic: -sem(ouralloc,@P==malloc(1n)) We would report the same message. Please note that it is necessary to designate that the returned area is freshly allocated (ala malloc). This message is always given in conjunction with the more general Informational Message 826. 434 White space ignored between back-slash and new-line -- According to the C and C++ standards, any back-slash followed immediately by a new-line results in the deletion of both characters. For example: #define A \ 34 defines A to be 34. If a blank or tab intervenes between the back-slash and the new-line then according to a strict interpretation of the standard you have defined A to be a back-slash. But this blank is invisible to the naked eye and hence could lead to confusion. Worse, some compilers silently ignore the white-space and the program becomes non-portable. You should never deliberately place a blank at the end of a line and any such blanks should be removed. If you really need to define a macro with a terminal back-slash you can use a comment as in: #define A \ /* commentary */ 435 integral constant 'String' has precision Integer, use +fll to enable long long" -- An integer constant was found that had a precision that was too large for a long but would fit within a long long. Yet the +fll flag that enables the long long type was not set. Check the sizes that you specified for long (-sl#) and for long long (-sll#) and make sure they are correct. Turn on +fll if your compiler supports long long. Otherwise use smaller constants. 436 Preprocessor directive in invocation of macro 'Symbol' at Location -- A function like macro was invoked whose arguments extended for multiple lines, which included preprocessor statements. This is almost certainly an error brought about by a missing right parenthesis. By the rules of Standard C the preprocessing directive is absorbed into the macro argument but then will not subsequently get executed. For this reason some compilers treat the apparent preprocessor directive as a directive. This is logical but not portable. It is therefore best to avoid this construct. 437 Passing struct 'Symbol' to ellipsis -- A struct is being passed to a function at a parameter position identified by an ellipsis. For example: void g() { struct A { int a; } x; void f( int, ... ); f( 1, x ); ... } This is sufficiently unusual that it is worth pointing out on the likelihood that this is unintended. The situation becomes more severe in the case of a Non-POD struct [10]. In this case the behavior is considered undefined. 501 Expected signed type -- The unary minus operator was applied to an unsigned type. The resulting value is a positive unsigned quantity and may not be what was intended. 502 Expected unsigned type -- Unary ~ being a bit operator would more logically be applied to unsigned quantities rather than signed quantities. 503 Boolean argument to relational -- Normally a relational would not have a Boolean as argument. An example of this is a < b < c, which is technically legal but does not produce the same result as the mathematical expression, which it resembles. 504 Unusual shift value -- Either the quantity being shifted or the amount by which a quantity is to be shifted was derived in an unusual way such as with a bit-wise logical operator, a negation, or with an unparenthesized expression. If the shift value is a compound expression that is not parenthesized, parenthesize it. 505 Redundant left argument to comma -- The left argument to the comma operator had no side effects in its top-most operator and hence is redundant. 506 Constant value Boolean -- A Boolean, i.e., a quantity found in a context that requires a Boolean such as an argument to && or || or an if() or while() clause or ! was found to be a constant and hence will evaluate the same way each time. 507 Size incompatibility -- A cast was made to an integral quantity from a pointer and according to other information given or implied it would not fit. For example a cast to an unsigned int was specified and information provided by the options indicate that a pointer is are larger than an int. 508 extern used with definition -- A function definition was accompanied with an extern storage class. extern is normally used with declarations rather than with definitions. At best the extern is redundant. At worst you may trip up a compiler. 509 extern used with definition -- A data object was defined with a storage class of extern. This is technically legal in ANSI and you may want to suppress this message. However, it can easily trip up a compiler and so the practice is not recommended at this time. 511 Size incompatibility -- A cast was made from an integral type to a pointer and the size of the quantity was too large to fit into the pointer. For example if a long is cast to a pointer and if options indicate that a long is larger than a pointer, this warning would be reported. 512 Symbol 'Symbol' previously used as static (Location) -- The Symbol name given is a function name that was declared as static in some other module (the location of that declaration is provided). The use of a name as static in one module and external in another module is legal but suspect. 514 Unusual use of a Boolean -- An argument to an arithmetic operator (+ - / * %) or a bit-wise logical operator (| & ^) was a Boolean. This can often happen by accident as in: if( flags & 4 == 0 ) where the ==, having higher precedence than &, is done first (to the puzzlement of the programmer). 515 Symbol 'Symbol' has arg. count conflict (Integer vs. Integer) with Location -- An inconsistency was found in the number of actual arguments provided in a function call and either the number of formal parameters in its definition or the number of actual arguments in some other function call. See the +fva option to selectively suppress this message. 516 Symbol 'Symbol' has arg. type conflict (no. Integer -- TypeDiff) with Location -- An inconsistency was found in the type of an actual argument in a function call with either the type of the corresponding formal parameter in the function definition or the type of an actual argument in another call to the same function or with the type specified for the argument in the function's prototype. The call is not made in the presence of a prototype. See options -ean, -eau, -eas and -eai Section 5.2 Error Inhibition Options for selective suppression of some kinds of type differences. If the conflict involves types char or short then you may want to consider using the +fxc or +fxs option. (Section 5.5 Flag Options) See also Section 15.4 Warning 516. 517 defined not K&R -- The defined function (not a K&R construct) was employed and the K&R preprocessor flag (+fkp) was set. Either do not set the flag or do not use defined. 518 Expected '(' -- sizeof type is not strict C. sizeof(type) or sizeof expression are both permissible. 519 Size incompatibility -- An attempt was made to cast a pointer to a pointer of unequal size. This could occur for example in a P model where pointers to functions require 4 bytes whereas pointers to data require only 2. This error message can be circumvented by first casting the pointer to an integral quantity (int or long) before casting to a pointer. 520 Expected void type, assignment, increment or decrement. -- The first expression of a for clause should either be an expression yielding the void type or be one of the privileged operators: assignment, increment, or decrement. See also message 522. 521 Expected void type, assignment, increment or decrement. -- The third expression of a for clause should either be an expression yielding the void type or be one of the privileged operators: assignment, increment, or decrement. See also message 522. 522 Expected void type, assignment, increment or decrement. -- If a statement consists only of an expression, it should either be an expression yielding the void type or be one of the privileged operators: assignment, increment, or decrement. Note that the statement *p++; draws this message but p++; does not. This message is frequently given in cases where a function is called through a pointer and the return value is not void. In this case we recommend a cast to void. If your compiler does not support the void type then you should use the -fvo option. 524 Loss of precision (Context) (Type to Type) -- There is a possible loss of a fraction in converting from a float to an integral quantity. Use of a cast will suppress this message. 525 Negative indentation from Location -- The current line was found to be negatively indented (i.e., not indented as much) from the indicated line. The latter corresponds to a clause introducing a control structure and statements and other control clauses and braces within its scope are expected to have no less indentation. If tabs within your program are other than 8 blanks you should use the -t option (See Section 11.). 526 Symbol 'Symbol' (Location) not defined -- The named external was referenced but not defined and did not appear declared in any library header file nor did it appear in a Library Module. This message is suppressed for unit checkout (-u option). Please note that a declaration, even one bearing prototype information is not a definition. See the glossary at the beginning of this chapter. If the Symbol is a library symbol, make sure that it is declared in a header file that you're including. Also make sure that the header file is regarded by PC-lint/FlexeLint as a Library Header file. Alternatively, the symbol may be declared in a Library Module. See Section 6.1 Library Header Files and Section 6.2 Library Modules for a further discussion. 527 Unreachable -- A portion of the program cannot be reached. 528 Symbol 'Symbol' (Location) not referenced -- The named static variable or static function was not referenced in the module after having been declared. 529 Symbol 'Symbol' (Location) not subsequently referenced -- The named variable was declared but not referenced in a function. 530 Symbol 'Symbol' (Location) not initialized -- An auto variable was used before it was initialized. 531 Field size too large for 'Symbol' -- The size given for a bit field of a structure exceeds the size of an int. 532 Return mode of function 'Symbol' inconsistent with Location -- A declaration (or a definition) of a function implies a different return mode than a previous statement. (The return mode of a function has to do with whether the function does, or does not, return a value). A return mode is determined from a declaration by seeing if the function returns void or, optionally, by observing whether an explicit type is given. See the fdr flag for a further explanation of this. See also the fvr and fvo flags in Section 5.5 Flag Options. 533 function 'Symbol' should (not) return a value (see Location) -- A return statement within a function (or lack of a return at the end of the function) implies a different return mode than a previous statement at Location (The return mode of a function has to do with whether the function does, or does not, return a value.) See also the fvr, fvo and fdr flags in Section 5.5 Flag Options. 534 Ignoring return value of function 'Symbol' (compare with Location) -- A function that returns a value is called just for side effects as, for example, in a statement by itself or the left-hand side of a comma operator. Try: (void) function(); to call a function and ignore its return value. See also the fvr, fvo and fdr flags in Section 5.5 Flag Options. 537 Repeated include file 'FileName' -- The file whose inclusion within a module is being requested has already been included in this compilation. The file is processed normally even if the message is given. If it is your standard practice to repeat included files then simply suppress this message. 538 Excessive size -- The size of an array equals or exceeds 64K bytes. 539 Did not expect positive indentation from Location -- The current line was found to be positively indented from a clause that did not control the line in question. For example: if( n > 0 ) x = 3; y = 4; will result in this warning being issued for y = 4;. The Location cited will be that of the if clause. See Section 11. 540 Excessive size -- A string initializer required more space than what was allocated. 541 Excessive size -- The size of a character constant specified with \xddd or \xhhh equaled or exceeded 2**b where b is the number of bits in a byte (established by the -sb option). The default is -sb8. 542 Excessive size for bit field -- An attempt was made to assign a value into a bit field that appears to be too small. The value to be assigned is either another bit field larger than the target, or a numeric value that is simply too large. You may cast the value to the generic unsigned type to suppress the error. You may get this message unexpectedly if the base of the bit field is an int. For example: struct { int b : 1 } s; s.b = 1; /* Warning - - requires 0 or -1 */ The solution in this case is to use 'unsigned' rather than 'int' in the declaration of b. 544 endif or else not followed by EOL -- The preprocessor directive #endif should be followed by an end-of-line. Some compilers specifically allow commentary to follow the #endif. If you are following that convention simply turn this error message off. 545 Suspicious use of & -- An attempt was made to take the address of an array name. At one time such an expression was officially illegal (K&R C [1]), was not consistently implemented, and was, therefore, suspect. However, the expression is legal in ANSI C and designates a pointer to an array. For example, given int a[10]; int (*p) [10]; Then a and &a, as pointers, both represent the same bit pattern, but whereas a is a pointer to int, &a is a pointer to array 10 of int. Of the two only &a may be assigned to p without complaint. If you are using the & operator in this way, we recommend that you disable this message. 546 Suspicious use of & -- An attempt was made to take the address of a function name. Since names of functions by themselves are promoted to address, the use of the & is redundant and could be erroneous. 547 Redefinition of symbol 'Symbol' conflicts with Location -- The indicated symbol had previously been defined (via #define) to some other value. 548 else expected -- A construct of the form if(e); was found, which was not followed by an else. This is almost certainly an unwanted semi-colon as it inhibits the if from having any effect. 549 Suspicious cast -- A cast was made from a pointer to some enumerated type or from an enumerated type to a pointer. This is probably an error. Check your code and if this is not an error, then cast the item to an intermediate form (such as an int or a long) before making the final cast. 550 Symbol 'Symbol' (Location) not accessed -- A variable (local to some function) was not accessed. This means that the value of a variable was never used. Perhaps the variable was assigned a value but was never used. Note that a variable's value is not considered accessed by autoincrementing or autodecrementing unless the autoincrement/decrement appears within a larger expression, which uses the resulting value. The same applies to a construct of the form: var += expression. If an address of a variable is taken, its value is assumed to be accessed. An array, struct or union is considered accessed if any portion thereof is accessed. 551 Symbol 'Symbol' (Location) not accessed -- A variable (declared static at the module level) was not accessed though the variable was referenced. See the explanation under message 550 (above) for a description of "access". 552 Symbol 'Symbol' (Location) not accessed -- An external variable was not accessed though the variable was referenced. See the explanation under message 550 above for a description of "access". 553 Undefined preprocessor variable 'Name', assumed 0 -- The indicated variable had not previously been defined within a #define statement and yet it is being used in a preprocessor condition of the form #if or #elif. Conventionally all variables in preprocessor expressions should be pre-defined. The value of the variable is assumed to be 0. 555 #elif not K&R -- The #elif directive was used and the K&R preprocessor flag (+fkp) was set. Either do not set the flag or do not use #elif. 556 indented # -- A preprocessor directive appeared indented within a line and the K&R preprocessor flag (+fkp) was set. Either do not set the flag or do not indent the #. 557 unrecognized format -- The format string supplied to printf, fprintf, sprintf, scanf, fscanf, or sscanf was not recognized. It is neither a standard format nor is it a user-defined format (see printf_code and scanf_code, Section 5.7 Other Options). 558 number of arguments inconsistent with format -- The number of arguments supplied to printf, sprintf, fprintf, scanf, fscanf or sscanf was inconsistent with the number expected as a result of analyzing the format string. 559 size of argument number Integer inconsistent with format -- The given argument (to printf, sprintf, or fprintf) was inconsistent with that which was anticipated as the result of analyzing the format string. Argument counts begin at 1 and include file, string and format specifications. For example, sprintf( buffer, "%f", 371 ) will show an error in argument number 3 because constant 371 is not floating point. 560 argument no. Integer should be a pointer -- The given argument (to one of the scanf or printf family of functions) should be a pointer. For the scanf family, all arguments corresponding to a format specification should be pointers to areas that are to be modified (receive the results of scanning). For the printf family, arguments corresponding to %s or %n also need to be pointers. Argument counts begin at 1 and include file, string and format specifications. For example scanf( "%f", 3.5 ) will generate the message that argument no. 2 should be a pointer. 561 (arg. no. Integer) indirect object inconsistent with format -- The given argument (to scanf, sscanf, or fscanf) was a pointer to an object that was inconsistent with that which was anticipated as the result of analyzing the format string. Argument counts begin at 1 and include file, string and format specifications. For example if n is declared as int then: scanf( "%c", &n ) will elicit this message for argument number 2. 562 Ellipsis (...) assumed -- Within a function prototype a comma was immediately followed by a right parenthesis. This is taken by some compilers to be equivalent to an ellipsis (three dots) and this is what is assumed by PC-lint/FlexeLint. If your compiler does not accept the ellipsis but makes this assumption, then you should suppress this message. 563 Label 'Symbol' (Location) not referenced -- The Symbol at the cited Location appeared as a label but there was no statement that referenced this label. 564 variable 'Symbol' depends on order of evaluation -- The named variable was both modified and accessed in the same expression in such a way that the result depends on whether the order of evaluation is left-to-right or right-to-left. One such example is: n + n++ since there is no guarantee that the first access to n occurs before the increment of n. Other, more typical cases, are given in Section 11.1 Order of Evaluation and Section 11.5 volatile Checking. Volatile variables are also checked for repeated use in an expression. See 565 tag 'Symbol' not previously seen, assumed file-level scope -- The named tag appeared in a prototype or in an inner block and was not previously seen in an outer (file-level) scope. The ANSI standard is dubious as to how this tag could link up with any other tag. For most compilers this is not an error and you can safely suppress the message. On the other hand, to be strictly in accord with ANSI C you may place a small stub of a declaration earlier in the program. For example: struct name; is sufficient to reserve a place for name in the symbol table at the appropriate level. 566 Inconsistent or redundant format char 'Char' -- This message is given for format specifiers within formats for the printf/scanf family of functions. The indicated character Char found in a format specifier was inconsistent or redundant with an earlier character found in the same format specifier. For example a format containing "%ls" will yield this error with the character 's' indicated. This is because the length modifier is designed to be used with integral or float conversions and has no meaning with the string conversion. Such characters are normally ignored by compilers. 567 Expected a numeric field before char 'Char' -- This message is given for format specifiers within formats for the printf/scanf family of functions. A numeric field or asterisk was expected at a particular point in the scanning of the format. For example: %-d requests left justification of a decimal integer within a format field. But since no field width is given, the request is meaning less. 568 nonnegative quantity is never less than zero. -- Comparisons of the form: u >= 0 0 <= u u < 0 0 > u are suspicious if u is an unsigned quantity or a quantity judged to be never less then 0. See also message 775. 569 Loss of information (Context) (Integer bits to Integer bits) -- An assignment (or implied assignment, see Context) was made from a constant to an integral variable that is not large enough to hold the constant. Examples include placing a hex constant whose bit requirement is such as to require an unsigned int into a variable typed as int. The number of bits given does not count the sign bit. 570 Loss of sign (Context) (Type to Type) -- An assignment (or implied assignment, see Context) is being made from a negative constant into an unsigned quantity. Casting the constant to unsigned will remove the diagnostic but is this what you want. If you are assigning all ones to an unsigned, remember that ~0 represents all ones and is more portable than -1. 571 Suspicious Cast -- Usually this warning is issued for casts of the form: (unsigned) ch where ch is declared as char and char is signed. Although the cast may appear to prevent sign extension of ch, it does not. Following the normal promotion rules of C, ch is first converted to int, which extends the sign and only then is the quantity cast to unsigned. To suppress sign extension you may use: (unsigned char) ch Otherwise, if sign extension is what you want and you just want to suppress the warning in this instance you may use: (unsigned) (int) ch Although these examples have been given in terms of casting a char they will also be given whenever this cast is made upon a signed quantity whose size is less than the casted type. Examples include signed bit fields (a possibility in the new standard), expressions involving char, and expressions involving short when this type is smaller than int or a direct cast of an int to an unsigned long (if int's is smaller than long). This message is not issued for constants or for expressions involving bit operations. 572 Excessive shift value (precision Integer shifted right by Integer) -- A quantity is being shifted to the right whose precision is equal to or smaller than the shifted value. For example, ch >> 10 will elicit this message if ch is typed char and where char is less than 10 bits wide (the usual case). To suppress the message in this case you may cast the shifted quantity to a type whose length is at least the length of the shift value. The precision of a constant (including enumeration constants) is determined from the number of bits required in its binary representation. The precision does not change with a cast so that still yields (unsigned) 1 >> 3 the message. But normally the only way an expression such as 1>>3 can legitimately occur is via a macro. In this case use -emacro. 573 Signed-unsigned mix with divide -- one of the operands to / or % was signed and the other unsigned; moreover the signed quantity could be negative. For example: u / n where u is unsigned and n is signed will elicit this message whereas: u / 4 will not, even though 4 is nominally an int. It is not a good idea to mix unsigned quantities with signed quantities in any case (a 737 will also be issued) but, with division, a negative value can create havoc. For example, the innocent looking: n = n / u will, if n is -2 and u is 2, not assign -1 to n but will assign some very large value. To resolve this problem, either cast the integer to unsigned if you know it can never be less than zero or cast the unsigned to an integer if you know it can never exceed the maximum integer. 574 Signed-unsigned mix with relational -- The four relational operators are: > >= < <= One of the operands to a relational operator was signed and the other unsigned; also, the signed quantity could be negative. For example: if( u > n ) ... where u is unsigned and n is signed will elicit this message whereas: if( u > 12 ) ... will not (even though 12 is officially an int it is obvious that it is not negative). It is not a good idea to mix unsigned quantities with signed quantities in any case (a 737 will also be issued) but, with the four relationals, a negative value can produce obscure results. For example, if the conditional: if( n < 0 ) ... is true then the similar appearing: u = 0; if( n < u ) ... is false because the promotion to unsigned makes n very large. To resolve this problem, either cast the integer to unsigned if you know it can never be less than zero or cast the unsigned to an int if you know it can never exceed the maximum int. 575 enumeration constant exceeds range for integers -- For many compilers the value of an enumeration constant is limited to those values that can fit within a signed or unsigned int. 577 Mixed memory model (option 'String') -- The indicated option requested a change to the memory model after part or all of another module was processed. The memory model option should be specified before any module is processed. The most common cause of this error is specifying the memory model after having specified the standard library. This would be a natural error to make if the standard library file were specified via a LINT environment variable. 578 Declaration of symbol 'Symbol' hides symbol 'Symbol' (Location) -- A local symbol has the identical name as a global symbol ( or possibly another local symbol). This could be dangerous. Was this deliberate? It is usually best to rename the local symbol. 579 parameter preceding ellipsis has invalid type -- When an ellipsis is used, the type preceding the ellipsis should not be a type that would undergo a default promotion such as char, short or float. The reason is that many compilers' variable argument schemes (using stdarg.h) will break down. 580 Redeclaration of function 'Symbol' (hiding Location) causes loss of prototype -- A declaration of a function within a block hides a declaration in an outer scope in such a way that the inner declaration has no prototype and the outer declaration does. A common misconception is that the resulting declaration is a composite of both declarations but this is only the case when the declarations are in the same scope not within nested scopes. If you don't care about prototypes you may suppress this message. You will still receive other type-difference warnings. 581 Option 'String' is obsolete and should no longer be used -- This message is issued whenever we encounter an option that appears to do more harm than good. 'String' is the option in question. 582 esym (or emacro) name 'String' should not contain '(' -- The name provided to esym should not contain a (. For example, to suppress message 534 when calling f(int) use the option -esym(534,f) even if f is overloaded. 601 Expected a type for symbol Symbol, int assumed -- A declaration did not have an explicit type. int was assumed. Was this a mistake? This could easily happen if an intended comma was replaced by a semicolon. For example, if instead of typing: double radius, diameter; the programmer had typed: double radius; diameter; this message would be raised. 602 Comment within comment -- The sequence /* was found within a comment. Was this deliberate? Or was a comment end inadvertently omitted? If you want PC-lint/FlexeLint to recognize nested comments you should set the Nested Comment flag using the +fnc option. Then this warning will not be issued. If it is your practice to use the sequence: /* /* */ then use -e602. 603 Symbol 'Symbol' (Location) not initialized -- The address of the named symbol is being passed to a function where the corresponding parameter is declared as pointer to const. This implies that the function will not modify the object. If this is the case then the original object should have been initialized sometime earlier. 604 Returning address of auto variable 'Symbol' -- The address of the named symbol is being passed back by a function. Since the object is an auto and since the duration of an auto is not guaranteed past the return, this is most likely an error. You may want to copy the value into a global variable and pass back the address of the global or you might consider having the caller pass an address of one of its own variables to the callee. 605 Increase in pointer capability (Context) -- This warning is typically caused by assigning a (pointer to const) to an ordinary pointer. For example: int *p; const int *q; p = q; /* 605 */ The message will be inhibited if a cast is used as in: p = (int *) q; An increase in capability is indicated because the const pointed to by q can now be modified through p. This message can be given for the volatile qualifier as well as the const qualifier and may be given for arbitrary pointer depths (pointers to pointers, pointers to arrays, etc.). If the number of pointer levels exceeds one, things get murky in a hurry. For example: const char ** ppc; char ** pp; pp = ppc; /* 605 - clearly not safe */ ppc = pp; /* 605 - looks safe but it's not */ It was not realized by the C community until very recently that assigning pp to ppc was dangerous. The problem is that after the above assignment, a pointer to a const char can be assigned indirectly through ppc and accessed through pp, which can then modify the const char. The message speaks of an "increase in capability" in assigning to ppc, which seems counter intuitive because the indirect pointer has less capability. However, assigning the pointer does not destroy the old one and the combination of the two pointers represents a net increase in capability. The message may also be given for function pointer assignments when the prototype of one function contains a pointer of higher capability than a corresponding pointer in another prototype. There is a curious inversion here whereby a prototype of lower capability translates into a function of greater trust and hence greater capability (a Trojan Horse). For example, let void warrior( char * ); be a function that destroys its argument. Consider the function: void Troy( void (*horse)(const char *) ); Troy() will call horse() with an argument that it considers precious believing the horse() will do no harm. Before compilers knew better and believing that adding in a const to the destination never hurt anything, earlier compilers allowed the Greeks to pass warrior() to Troy and the rest, as they say, is history. 606 Non-ANSI escape sequence: '\String' -- An escape sequence occurred, within a character or string literal, that was not on the approved list, which is: \' \" \? \\ \a \b \f \n \r \t \v \octal-digits \xhex-digits 607 Parameter 'Symbol' of macro found within string -- The indicated name appeared within a string or character literal within a macro and happens to be the same as the name of a formal parameter of the macro as in: #define mac(n) printf( "n = %d,", n ); Is this a coincidence? The ANSI standard indicates that the name will not be replaced but since many C compilers do replace such names the construction is suspect. Examine the macro definition and if you do not want substitution, change the name of the parameter. If you do want substitution, set the +fps flag (Parameter within String) and suppress the message with -e607. 608 Assigning to an array parameter -- An assignment is being made to a parameter that is typed array. For the purpose of the assignment, the parameter is regarded as a pointer. Normally such parameters are typed as pointers rather than arrays. However if this is your coding style you should suppress this message. 609 Suspicious pointer conversion -- An assignment is being made between two pointers, which differ in size (one is far and the other is near) but are otherwise compatible. 610 Suspicious pointer combination -- Pointers of different size (one is far and the other is near) are being compared, subtracted, or paired (in a conditional expression). This is suspicious because normally pointers entering into such operations are the same size. 611 Suspicious cast -- Either a pointer to a function is being cast to a pointer to an object or vice versa. This is regarded as questionable by the ANSI standard. If this is not a user error, suppress this warning. 612 Expected a declarator -- A declaration contained just a storage class and a type. This is almost certainly an error since the only time a type without a declarator makes sense is in the case of a struct, union or enum but in that case you wouldn't use a storage class. 613 Possible use of null pointer 'Symbol' in [left/right] argument to operator 'String' Reference -- From information gleaned from earlier statements, it is possible that a null pointer (a pointer whose value is 0) can be used in a context where null pointers are inappropriate. Such contexts include: Unary *, pointer increment (++) or decrement(--), addition of pointer to numeric, and subtraction of two pointers. In the case of binary operators, one of the words 'left' or 'right' is used to designate which operand is null. Symbol identifies the pointer variable that may be NULL. See also messages 413 and 794. 614 auto aggregate initializer not constant -- An initializer for an auto aggregate normally consists of a collection of constant-valued expressions. Some compilers may, however, allow variables in this context in which case you may suppress this message. 615 auto aggregate initializer has side effects -- This warning is similar to 614. Auto aggregates (arrays, structures and union) are normally initialized by a collection of constant-valued expressions without side-effects. A compiler could support side-effects in which case you might want to suppress this message. 616 control flows into case/default -- It is possible for flow of control to fall into a case statement or a default statement from above. Was this deliberate or did the programmer forget to insert a break statement? If this was deliberate then place a comment immediately before the statement that was flagged as in: case 'a': a = 0; /* fall through */ case 'b': a++; Note that the message will not be given for a case that merely follows another case without an intervening statement. Also, there must actually be a possibility for flow to occur from above. 617 String is both a module and an include file -- The named file is being used as both an include file and as a module. Was this a mistake? Unlike Error 306 (repeated module) this is just a warning and processing of the file is attempted. 618 Storage class specified after a type -- A storage class specifier (static, extern, typedef, register or auto) was found after a type was specified. This is legal but deprecated. Either place the storage class specifier before the type or suppress this message. 619 Loss of precision (Context) (Pointer to Pointer) -- A far pointer is being assigned to a near pointer either in an assignment statement or an implied assignment such as an initializer, a return statement, or passing an argument in the presence of a prototype (Context indicates which). Such assignments are a frequent source of error when the actual segment is not equal to the default data segment. If you are sure that the segment of the far pointer equals the default data segment you should use a cast to suppress this message. 620 Suspicious constant (L or one?) -- A constant ended in a lower-case letter 'l'. Was this intended to be a one? The two characters look very similar. To avoid misinterpretations, use the upper-case letter 'L'. 621 Identifier clash (Symbol 'Name' with Symbol 'Name' at String) -- The two symbols appeared in the same name space but are identical to within the first count characters set by option -idlen(count,option). See -idlen in Section 5.7 Other Options. 622 Size of argument no. Integer inconsistent with format -- The argument to scanf, fscanf or sscanf, where position is given by Integer, was a pointer whose size did not match the format. For example, int far *p; scanf( "%d", p ); will draw this warning (in the default memory model). 623 redefining the storage class of symbol 'Symbol' conflicts with Location -- An inter-module symbol was a typedef symbol in one module and an ordinary symbol in another module. This is legal but potentially confusing. Is this what the programmer intended? 624 typedef 'Symbol' redeclared (TypeDiff) (Location) -- A symbol was declared in a typedef differently in two different modules. This is technically legal but is not a wise programming practice. 625 auto symbol 'Symbol' has unusual type modifier -- Some type modifiers such as far, near, fortran are inappropriate for auto variables. 626 argument no. Integer inconsistent with format -- The argument to a printf (or fprintf or sprintf) was inconsistent with the format. Although the size of the quantity was appropriate the type was not. You might consider casting the quantity to the correct type. You could also suppress this message, as more flagrant violations are picked up with warning 559. 627 (arg. no. Integer) indirect object inconsistent with format -- The type of an argument to scanf (or fscanf or sscanf) was inappropriate to the format. However, the argument was a pointer and it pointed to a quantity of the expected size. 628 no argument information provided for function 'Symbol' (Location) -- The named function was called but there was no argument information supplied. Argument information can come from a prototype or from a function definition. This usually happens when an old-style function decla ration indicates that the function is in a library but no prototype is given for the function nor is any argument information provided in a standard library file. This message is suppressed if you are producing a lint object module because presumably the object module will be compared with a library file at some later time. 629 static class for function 'Symbol' is non standard -- A static class was found for a function declaration within a function. The static class is only permitted for functions in declarations that have file scope (i.e., outside any function). Either move the declaration outside the function or change static to extern; if the second choice is made, make sure that a static declaration at file scope also exists before the extern declaration. Though technically the construct is not portable, many compilers do tolerate it. If you suppress the message, PC-lint/FlexeLint will treat it as a proper function declaration. 630 ambiguous reference to symbol 'Name' -- If the +fab flag is set, then if two structures containing the same member name (not necessarily different kinds of structures) are embedded in the same structure and a reference to this member name omits one of the intervening (disambiguating) names, this warning is emitted. 631 tag 'Symbol' defined differently at Location -- The struct, union or enum tag Symbol was defined differently in different scopes. This is not necessarily an error since C permits the redefinition, but it can be a source of subtle error. It is not generally a programming practice to be recommended. 632 Assignment to strong type 'Name' in context: Context -- An assignment (or implied assignment, Context indicates which) violates a Strong type check as requested by a -strong(A... option. See Chapter 8. 633 Assignment from a strong type 'Name' in context: Context -- An assignment (or implied assignment, Context indicates which) violates a Strong type check as requested by a -strong(X... option. See Chapter 8. 634 Strong type mismatch (type 'Symbol') in equality or conditional -- An equality operation (== or !=) or a conditional operation (? :) violates a Strong type check as requested by a -strong(J... option. This message would have been suppressed using flags "Je". See Chapter 8. 635 resetting strong parent of type 'Symbol', old parent == type 'Symbol' -- The strong parent of the given Symbol is being reset. This is being done with a -parent option or by a typedef. Note that this may not necessarily be an error; you are being alerted to the fact that the old link is being erased. See Chapter 8. 636 ptr to strong type 'Name' versus another type -- Pointers are being compared and there is a strong type clash below the first level. For example, /*lint -strong(J,INT) */ typedef int INT; INT *p; int *q; if( p == q ) /* Warning 636 */ will elicit this warning. This message would have been suppressed using flags "Je" or "Jr" or both. 637 Expected index type 'Symbol' for strong type 'Symbol' -- This is the message you receive when an inconsistency with the -index option is recognized. A subscript is not the stipulated type (the first type mentioned in the message) nor equivalent to it within the hierarchy of types. See Chapter 8. STRONG TYPES and also +fhx. 638 Strong type mismatch for type 'Name' in relational -- A relational operation ( >= <= > < ) violates a Strong type check as requested by a -strong(J... option. This message would have been suppressed using flags "Jr". See Chapter 8. 639 Strong type mismatch for type 'Name' in binary operation -- A binary operation other than an equality or a relational operation violates a Strong type check as requested by a -strong(J... option. This message would have been suppressed using flags "Jo". See Chapter 8. 640 Expected strong type 'Name' in Boolean context -- A Boolean context expected a type specified by a -strong(B... option. See Chapter 8. 641 Converting enum to int -- An enumeration type was used in a context that required a computation such as an argument to an arithmetic operator or was compared with an integral argument. This warning will be suppressed if you use the integer model of enumeration (+fie) but you will lose some valuable type-checking in doing so. An intermediate policy is to simply turn off this warning. Assignment of int to enum will still be caught. This warning is not issued for a tagless enum without variables. For example enum {false,true}; This cannot be used as a separate type. PC-lint/FlexeLint recognizes this and treats false and true as arithmetic constants. 642 Format char 'Char' not supported by wsprintf -- This means that you are using an option of the form: -printf(w... and you are using a format character not supported by the Microsoft Windows function wsprintf. If you are not really using wsprintf but are using the w flag to get far pointers you should turn this message off. 643 Loss of precision in pointer cast -- A far pointer was cast to a near pointer. Such casts have had disastrous consequences for Windows programmers. If you really need to make such a cast, you can do it in stages. If you cast to a long first (i.e., some integral type that can hold the pointer) and then into a shorter value, we don't complain. 644 Variable 'Symbol' (Location) may not have been initialized -- An auto variable was not necessarily assigned a value before use. See Section 9. 645 Symbol 'Symbol' (Location) may not have been initialized -- An auto variable was conditionally assigned a value before being passed to a function expecting a pointer to a const object. See Warning 603 for an explanation of the dangers of such a construct. See Section 9. 646 case/default within Kind loop; may have been misplaced -- A case or default statement was found within a for, do, or while loop. Was this intentional? At the very least, this reflects poor programming style. 647 Suspicious truncation -- This message is issued when it appears that there may have been an unintended loss of information during an operation involving int or unsigned int the result of which is later converted to long. It is issued only for systems in which int is smaller than long. For example: (long) (n << 8) might elicit this message if n is unsigned int, whereas (long) n << 8 would not. In the first case, the shift is done at int precision and the high order 8 bits are lost even though there is a subsequent conversion to a type that might hold all the bits. In the second case, the shifted bits are retained. The operations that are scrutinized and reported upon by this message are: shift left, multiplication, and bit-wise complementation. Addition and subtraction are covered by Informational message 776. The conversion to long may be done explicitly with a cast as shown or implicitly via assignment, return, argument passing or initialization. The message can be suppressed by casting. You may cast one of the operands so that the operation is done in full precision as is given by the second example above. Alternatively, if you decide there is really no problem here (for now or in the future), you may cast the result of the operation to some form of int. For example, you might write: (long) (unsigned) (n << 8) In this way PC-lint/FlexeLint will know you are aware of and approve of the truncation. 648 Overflow in computing constant for operation: String -- Arithmetic overflow was detected while computing a constant expression. For example, if int is 16 bits then 200 * 200 will result in an overflow. String gives the operation that caused the overflow and may be one of: addition, unsigned addition, multiplication, unsigned multiplication, negation, shift left, unsigned shift left, subtraction, or unsigned sub. To suppress this message for particular constant operations you may have to supply explicit truncation. For example, if you want to obtain the low order 8 bits of the integer 20000 into the high byte of a 16-bit int, shifting left would cause this warning. However, truncating first and then shifting would be OK. The following code illustrates this where int is 16 bits. 20000u << 8; /* 648 */ (0xFF & 20000u) << 8; /* OK */ If you truncate with a cast you may make a signed expression out of an unsigned. For example, the following receives a warning (for 16 bit int). (unsigned char) OxFFFu << 8 /* 648 */ because the unsigned char is promoted to int before shifting. The resulting quantity is actually negative. You would need to revive the unsigned nature of the expression with (unsigned) (unsigned char) OxFFF << 8 /* OK */ 649 Sign fill during constant shift -- During the evaluation of a constant expression a negative integer was shifted right causing sign fill of vacated positions. If this is what is intended, suppress this error, but be aware that sign fill is implementation-dependent. 650 Constant out of range for operator String -- In a comparison operator or equality test (or implied equality test as for a case statement), a constant operand is not in the range specified by the other operand. For example, if 300 is compared against a char variable, this warning will be issued. Moreover, if char is signed (and 8 bits) you will get this message if you compare against an inte ger greater than 127. The problem can be fixed with a cast. For example: if( ch == 0xFF ) ... if( (unsigned char) ch == 0xFF ) ... If char is signed (+fcu has not been set) the first receives a warning and can never succeed. The second suppresses the warning and corrects the bug. PC-lint/FlexeLint will take into account the limited precision of some operands such as bit-fields and enumerated types. Also, PC-lint/FlexeLint will take advantage of some computations that limit the precision of an operand. For example, if( (n & 0xFF) >> 4 == 16 ) ... will receive this warning because the left-hand side is limited to 4 bits of precision. 651 Potentially confusing initializer -- An initializer for a complex aggregate is being processed that contains some subaggregates that are bracketed and some that are not. ANSI recommends either "minimally bracketed" initializers in which there are no interior braces or "fully bracketed" initializers in which all interior aggregates are bracketed. 652 #define of symbol 'Symbol' declared previously at Location -- A macro is being defined for a symbol that had previously been declared. For example: int n; #define n N will draw this complaint. Prior symbols checked are local and global variables, functions and typedef symbols, and struct, union and enum tags. Not checked are struct and union member. 653 Possible loss of fraction -- When two integers are divided and assigned to a floating point variable the fraction portion is lost. For example, although double x = 5 / 2; appears to assign 2.5 to x it actually assigns 2.0. To make sure you don't lose the fraction, cast at least one of the operands to a floating point type. If you really wish to do the truncation, cast the resulting divide to an integral (int or long) before assigning to the floating point variable. 654 Option String obsolete; use -width(W,I) -- The option -w is now used to set the warning level and should no longer be used to specify the width of error messages. Instead use -width with the same arguments as before to set the width. To set the warning level to 3, for example, use the option -w3, not -w(3). 655 bit-wise operation uses (compatible) enum's -- A bit-wise operator (one of '|', '&' or '^') is used to combine two compatible enumerations. The type of the result is considered to be the enumeration. This is considered a very minor deviation from the strict model and you may elect to suppress this warning. 656 Arithmetic operation uses (compatible) enum's -- An arithmetic operator (one of '+', or '-') is used to combine two compatible enumerations. The type of the result is considered to be the enumeration. This is considered a very minor deviation from the strict model and you may elect to suppress this warning. 657 Unusual (nonportable) anonymous struct or union -- A struct or union declaration without a declarator was taken to be anonymous. However, the anonymous union supported by C++ and other dialects of C require untagged union's. Tagged unions and tagged or untagged structs are rarely supported, as anonymous. 658 Anonymous union assumed (use flag +fan) -- A union without a declarator was found. Was this an attempt to define an anonymous union? If so, anonymous unions should be activated with the +fan flag. This flag is activated automatically for C++. 659 Nothing follows '}' on line within struct/union/enum declaration -- A struct/union/class/enum definition occurred and the closing '}' was not followed on the same line by another token. It looks suspicious. Missing semi-colons after such definitions can be a source of strange and mysterious messages. If you intentionally omitted the semi-colon then simply place the token, which follows, on the same line as the '}'. At the very least follow the '}' with a comment. 660 Option String has no effect -- The indicated option had no effect. Was this a mistake? Not all options are tested for effectiveness. For example, in the sequence -w2 -e720 the 2nd option has no effect but no report is given since the nuisance value would be too high. The message is reserved for cases when the non-effectiveness would produce truly mysterious results. 661 possible access of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer may have been accessed. See message 415 for a description of the parameters Integer and String. For example: int a[10]; if( n <= 10 ) a[n] = 0; Here the programmer presumably should have written n<10. This message is similar to messages 415 and 796 but differs from them by the degree of probability. See Section 9. 662 possible creation of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer may have been created. See message 415 for a description of the parameters Integer and String. For example: int a[10]; if( n <= 20 ) f( a + n ); Here, it appears as though an illicit pointer is being created, but PC-lint/FlexeLint cannot be certain. See also messages 416 and 797. See Section 9. 663 Suspicious array to pointer conversion -- This warning occurs in the following kind of situation: struct x { int a; } y[2]; ... y->a ... Here, the programmer forgot to index the array but the error normally goes undetected because the array reference is automatically and implicitly converted to a pointer to the first element of the array. If you really mean to access the first element use y[0].a 664 Left side of logical OR (||) or logical AND (&&) does not return -- An exiting function was found on the left hand side of an operator implying that the right hand side would never be executed. For example: if( (exit(0),n == 0) || n > 2 ) ... Since the exit function does not return, control can never flow to the right hand operator. 665 Unparenthesized parameter Integer in macro 'Symbol' is passed an expression -- An expression was passed to a macro parameter that was not parenthesized. For example: #define mult(a,b) (a*b) ... mult( 100, 4 + 10 ) Here the programmer is beguiled into thinking that the 4+10 is taken as a quantity to be multiplied by 100 but instead results in: 100*4+10, which is quite different. The recommended remedy ( [22 section 20.4]) is to parenthesize such parameters as in: #define mult(a,b) ((a)*(b)) The message is not arbitrarily given for any unparenthesized parameter but only when the actual macro argument sufficiently resembles an expression and the expression involves binary operators. The priority of the operator is not considered except that it must have lower priority than the unary operators. The message is not issued at the point of macro definition because it may not be appropriate to parenthesize the parameter. For example, the following macro expects that an operator will be passed as argument. It would be an error to enclose op in parentheses. #define check(x,op,y) if( ((x) op (y)) == 0 ) print( ... ) 666 Expression with side effects passed to repeated parameter Integer of macro 'Symbol' -- A repeated parameter within a macro was passed an argument with side-effects. For example: #define ABS(x) ((x) < 0 ? -(x) : (x)) ... ABS( n++ ) Although the ABS macro is correctly defined to specify the absolute value of its argument, the repeated use of the parameter x implies a repeated evaluation of the actual argument n++. This results in two increments to the variable n. [22 section 20.6] Any expression containing a function call is also considered to have side-effects. 667 Inconsistent use of qualifiers for symbol 'Symbol' (type 'Type' vs. 'Type') conflicts with Location -- A declaration for the identified Symbol is inconsistent with a prior declaration for the same symbol. There was a nominal difference in the declaration but owing to the memory model chosen there was no real difference. For example, in large model, one declaration declares external symbol alpha to be a far pointer and another declaration omits the memory model specification. 668 Possibly passing a null pointer to function 'Symbol', Context Reference -- A NULL pointer is possibly being passed to a function identified by Symbol. The argument in question is given by Context. The function is either a library function designed not to receive a NULL pointer or a user function dubbed so via the option -function. See Section 10.1 Function Mimicry (function) and Section 9.2 Value Tracking. 669 Possible data overrun for function 'Symbol', argument Integer exceeds argument Integer Reference -- This message is for data transfer functions such as memcpy, strcpy, fgets, etc. when the size indicated by the first cited argument (or arguments) can possibly exceed the size of the buffer area cited by the second. The message may also be issued for user functions via the -function option. See Section 10.1 Function Mimicry (function) and Section 9.2 Value Tracking. 670 Possible access beyond array for function 'Symbol', argument Integer exceeds Integer Reference -- This message is issued for several library functions (such as fwrite, memcmp, etc) wherein there is a possible attempt to access more data than exist. For example, if the length of data specified in the fwrite call exceeds the size of the data specified. The function is specified by Symbol and the arguments are identified by argument number. See also Section 10.1 Function Mimicry (function) and Section 9.2 Value Tracking. 671 Possibly passing to function 'Symbol' a negative value (Integer), Context Reference -- An integral value that may possibly be negative is being passed to a function that is expecting only positive values for a particular argument. The message contains the name of the function (Symbol), the questionable value (Integer) and the argument number (Context). The function may be a standard library function designed to accept only positive values such as malloc or memcpy (third argument), or may have been identified by the user as such through the -function or -sem options. See message 422 for an example and further explanation. 672 Possible memory leak in assignment to pointer 'Symbol' -- An assignment was made to a pointer variable (designated by Symbol), which may already be holding the address of an allocated object, which had not been freed. The allocation of memory, which is not freed, is considered a 'memory leak'. The memory leak is considered 'possible' because only some lines of flow will result in a leak. 673 Possibly inappropriate deallocation (Name1) for 'Name2' data -- This message indicates that a deallocation (free(), delete, or delete[]) as specified by Name1 may be inappropriate for the data being freed. The kind of data is one or more of: malloc, new, new[], static, auto, member, modified or constant. The word 'Possibly' is used in the message to indicate that only some of the lines of flow to the deallocation show data inconsistent with the allocation. 674 Returning address of auto through variable 'Symbol' -- The value held by a pointer variable contains the address of an auto variable. It is normally incorrect to return the address of an item on the stack because the portion of the stack allocated to the returning function is subject to being obliterated after return. 675 No prior semantics associated with 'Name' in option 'String' -- The -function option is used to transfer semantics from its first argument to subsequent arguments. However it was found that the first argument Name did not have semantics. 676 Possibly negative subscript (Integer) in operator 'String' -- An integer whose value was possibly negative was added to an array or to a pointer to an allocated area (allocated by malloc, operator new, etc.) This message is not given for pointers whose origin is unknown since a negative subscript is in general legal. 677 sizeof used within preprocessor statement -- Whereas the use of sizeof during preprocessing is supported by a number of compilers it is not a part of the ANSI C or C++ standard. 678 Member 'Symbol' field length (Integer) too small for enum precision (Integer) -- A bit field was found to be too small to support all the values of an enumeration (that was used as the base of the bit field). For example: enum color { red, green, yellow, blue }; struct abc { enum color c:2; }; Here, the message is not given because the four enumeration values of color will just fit within 2 bits. However, if one additional color is inserted, Warning 678 will be issued informing the programmer of the undesirable and dangerous condition. 679 Suspicious Truncation in arithmetic expression combining with pointer -- This message is issued when it appears that there may have been an unintended loss of information during an operation involving integrals before combining with a pointer whose precision is greater than the integral expression. For example: //lint -sp8 pointers are 8 bytes //lint -si4 integers are 4 bytes char *f( char *p, int n, int m ) { return p + (n + m); // warning 679 } By the rules of C/C++, the addition n+m is performed independently of its context and is done at integer precision. Any overflow is ignored even though the larger precision of the pointer could easily accommodate the overflow. If, on the other hand the expression were: p+n+m, which parses as (p+n)+m, no warning would be issued. If the expression were p+n*m then, to suppress the warning, a cast is needed. If long were the same size as pointers you could use the expression: return p + ((long) n * m); 680 Suspicious Truncation in arithmetic expression converted to pointer -- An arithmetic expression was cast to pointer. Moreover, the size of the pointer is greater than the size of the expression. In computing the expression, any overflow would be lost even though the pointer type would be able to accommodate the lost information. To suppress the message, cast one of the operands to an integral type large enough to hold the pointer. Alternatively, if you are sure there is no prob lem you may cast the expression to an integral type before casting to pointer. See messages 647, 776, 790 and 679. 681 Loop is not entered -- The controlling expression for a loop (either the expression within a while clause or the second expression within a for clause) evaluates initially to 0 and so it appears as though the loop is never entered. 682 sizeof applied to a parameter 'Symbol' whose type is a sized array -- If a parameter is typed as an array it is silently promoted to pointer. Taking the size of such an array will actually yield the size of a pointer. Consider, for example: unsigned f( char a[100] ) { return sizeof(a); } Here it looks as though function f() will return the value 100 but it will actually return the size of a pointer, which is usually 4. 683 function 'Symbol' #define'd -- This message is issued whenever the name of a function with some semantic association is defined as a macro. For example: #define strlen mystrlen will raise this message. The problem is that the semantics defined for strlen will then be lost. Consider this message an alert to transfer semantics from strlen to mystrlen, using -function(strlen, mystrlen) The message will be issued for built-in functions (with built-in semantics) or for user-defined semantics. The message will not be issued if the function is defined to be a function with a similar name but with underscores either appended or prepended or both. For example: #define strlen __strlen will not produce this message. It will produce Info 828 instead. 684 Passing address of auto variable 'Symbol' into caller space -- The address of an auto variable was passed via assignment into a location specified by the caller to the function. For example: void f( int *a[] ) { int n; a[1] = &n; } Here the address of an auto variable (n) is being passed into the second element of the array passed to the function f. This looks suspicious because upon return the array will contain a pointer to a variable whose lifetime is over. It is possible that this is benign since it could be that the caller to f() is merely passing in a working space to be discarded upon return. If this is the case, you can suppress the message for function f() using the option -efunc(684,f) See also Warning 604. 685 Relational operator 'String,' always evaluates to 'String' -- The first String is one of '>', '>=', '<' or '<=' and identifies the relational operator. The second string is one of 'True' or 'False'. The message is given when an expression is compared to a constant and the precision of the expression indicates that the test will always succeed or always fail. For example, char ch; ... if( ch >= -128 ) ... In this example, the precision of char ch is 8 bits signed (assuming the fcu flag has been left in the OFF state) and hence it has a range of values from -128 to 127 inclusive. Hence the test is always True. Note that, technically, ch is promoted to int before comparing with the constant. For the purpose of this comparison we consider only the underlying precision. As another example, if u is an unsigned int then if( (u & 0xFF) > 0xFF ) ... will also raise message 685 because the expression on the left hand side has an effective precision of 16 bits. 17.5 C Informational Messages 701 Shift left of signed quantity (int) -- Shifts are normally accomplished on unsigned operands. 702 Shift right of signed quantity (int) -- Shifts are normally accomplished on unsigned operands. Shifting an int right is machine dependent (sign fill vs. zero fill). 703 Shift left of signed quantity (long) -- Shifts are normally accomplished on unsigned operands. 704 Shift right of signed quantity (long) -- Shifts are normally accomplished on unsigned operands. Shifting a long right is machine dependent (sign fill vs. zero fill). 708 union initialization -- There was an attempt to initialize the value of a union. This may not be permitted in some older C compilers. This is because of the apparent ambiguity: which member should be initialized. The standard interpretation is to apply the initialization to the first subtype of the union. 712 Loss of precision (Context) (Type to Type) -- An assignment (or implied assignment, see Context) is being made between two integral quantities in which the first Type is larger than the second Type. A cast will suppress this message. 713 Loss of precision (Context) (Type to Type) -- An assignment (or implied assignment, see Context) is being made from an unsigned quantity to a signed quantity, that will result in the possible loss of one bit of integral precision such as converting from unsigned int to int. A cast will suppress the message. 714 Symbol 'Symbol' (Location) not referenced -- The named external variable or external function was defined but not referenced. This message is suppressed for unit checkout (-u option). 715 Symbol 'Symbol' (Location) not referenced -- The named formal parameter was not referenced. 716 while(1) ... -- A construct of the form while(1) ... was found. Whereas this represents a constant in a context expecting a Boolean, it may reflect a programming policy whereby infinite loops are prefixed with this construct. Hence it is given a separate number and has been placed in the informational category. The more conventional form of infinite loop prefix is for(;;) 717 do ... while(0) -- Whereas this represents a constant in a context expecting a Boolean, this construct is probably a deliberate attempt on the part of the programmer to encapsulate a sequence of statements into a single statement, and so it is given a separate error message. [22 section 20.7] For example: #define f(k) do {n=k; m=n+1;} while(0) allows f(k) to be used in conditional statements as in if(n>0) f(3); else f(2); Thus, if you are doing this deliberately use -e717 718 Symbol 'Symbol' undeclared, assumed to return int -- A function was referenced without (or before) it had been declared or defined within the current module. This is not necessarily an error and you may want to suppress such messages (See Chapter 14.). Note that by adding a declaration to another module, you will not suppress this message. It can only be suppressed by placing a declaration within the module being processed. 719 Too many arguments for format (Integer too many) -- The number of arguments to a function in the printf/scanf family was more than what is specified in the format. This message is similar to Warning 558, which alerts users to situations in which there were too few arguments for the format. It receives a lighter Informational classification because the additional arguments are simply ignored. 720 Boolean test of assignment -- An assignment was found in a context that requires a Boolean (such as in an if() or while() clause or as an operand to && or ||). This may be legitimate or it could have resulted from a mistaken use of = for ==. 721 Suspicious use of ; -- A semi-colon was found immediately to the right of a right parenthesis in a construct of the form if(e);. As such it may be overlooked or confused with the use of semi-colons to terminate statements. The message will be inhibited if the ';' is separated by at least one blank from the ')'. Better, place it on a separate line. See also message 548. 722 Suspicious use of ; -- A semi-colon was found immediately to the right of a right parenthesis in a construct of the form while(e); or for(e;e;e); As such it may be overlooked or confused with the use of semi-colons to terminate statements. The message will be inhibited if the ';' is separated by at least one blank from the ')'. Better, place it on a separate line. 723 Suspicious use of = -- A preprocessor definition began with an = sign. For example: #define LIMIT = 50 Was this intentional? Or was the programmer thinking of assignment when he wrote this? 725 Expected positive indentation from Location -- The current line was found to be aligned with, rather than indented with respect to, the indicated line. The indicated line corresponds to a clause introducing a control structure and statements within its scope are expected to be indented with respect to it. If tabs within your program are other than 8 blanks you should use the -t option (See Section 11.). 726 Extraneous comma ignored -- A comma followed by a right-brace within an enumeration is not a valid ANSI construct. The comma is ignored. 727 Symbol 'Symbol' (Location) not explicitly initialized -- The named static variable (local to a function) was not explicitly initialized before use. The following remarks apply to messages 728 and 729 as well as 727. By no explicit initialization we mean that there was no initializer present in the definition of the object, no direct assignment to the object, and no address operator applied to the object or, if the address of the object was taken, it was assigned to a pointer to const. These messages do not necessarily signal errors since the implicit initialization for static variables is 0. However, the messages are helpful in indicating those variables that you had forgotten to initialize to a value. To extract the maximum benefit from the messages we suggest that you employ an explicit initializer for those variables that you want to initialize to 0. For example: static int n = 0; For variables that will be initialized dynamically, do not use an explicit initializer as in: static int m; This message will be given for any array, struct or union if no member or element has been assigned a value. 728 Symbol 'Symbol' (Location) not explicitly initialized -- The named intra-module variable (static variable with file scope) was not explicitly initialized. See the comments on message 727 for more details. 729 Symbol 'Symbol' (Location) not explicitly initialized -- The named inter-module variable (external variable) was not explicitly initialized. See the comments on message 727 for more details. This message is suppressed for unit checkout (-u). 730 Boolean argument to function -- A Boolean was used as an argument to a function. Was this intended? Or was the programmer confused by a particularly complex conditional statement. Experienced C programmers often suppress this message. This message is given only if the associated parameter is not declared bool. 731 Boolean argument to equal/not equal -- A Boolean was used as an argument to == or !=. For example: if( (a > b) == (c > d) ) ... tests to see if the inequalities are of the same value. This could be an error as it is an unusual use of a Boolean (see Warnings 503 and 514) but it may also be deliberate since this is the only way to efficiently achieve equivalence or exclusive or. Because of this possible use, the construct is given a relatively mild 'informational' classification. If the Boolean argument is cast to some type, this message is not given. 732 Loss of sign (Context) (Type to Type) -- An assignment (or implied assignment, see Context) is made from a signed quantity to an unsigned quantity. Also, it could not be determined that the signed quantity had no sign. For example: u = n; /* Info 732 */ u = 4; /* OK */ where u is unsigned and n is not, warrants a message only for the first assignment, even though the constant 4 is nominally a signed int. Make sure that this is not an error (that the assigned value is never negative) and then use a cast (to unsigned) to remove the message. 733 Assigning address of auto variable 'Symbol' to outer scope symbol 'Symbol' -- The address of an auto variable is only valid within the block in which the variable is declared. An address to such a variable has been assigned to a variable that has a longer life expectancy. There is an inherent danger in doing this. 734 Loss of precision (Context) (Integer bits to Integer bits) -- An assignment is being made into an object smaller than an int. The information being assigned is derived from another object or combination of objects in such a way that information could potentially be lost. The number of bits given does not count the sign bit. For example if ch is a char and n is an int then: ch = n; will trigger this message whereas: ch = n & 1; will not. To suppress the message a cast can be made as in: ch = (char) n; You may receive notices involving multiplication and shift operators with subinteger variables. For example: ch = ch << 2 ch = ch * ch where, for example, ch is an unsigned char. These can be suppressed by using the flag +fpm (precision of an operator is bound by the maximum of its operands). See Section 5. 735 Loss of precision (Context) (Integer bits to Integer bits) -- An assignment (or implied assignment, see Context) is made from a long double to a double. Using a cast will suppress the message. The number of bits includes the sign bit. 736 Loss of precision (Context) (Integer bits to Integer bits) -- An assignment (or implied assignment, see Context) is being made to a float from a value or combination of values that appear to have higher precision than a float. You may suppress this message by using a cast. The number of bits includes the sign bit. 737 Loss of sign in promotion from Type to Type -- An unsigned quantity was joined with a signed quantity in a binary operator (or 2nd and 3rd arguments to the conditional operator ? :) and the signed quantity is implicitly converted to unsigned. The message will not be given if the signed quantity is an unsigned constant, a Boolean, or an expression involving bit manipulation. For example, u & ~0xFF where u is unsigned does not draw the message even though the operand on the right is technically a signed integer constant. It looks enough like an unsigned to warrant not giving the message. This mixed mode operation could also draw Warnings 573 or 574 depending upon the operator involved. You may suppress the message with a cast but you should first determine whether the signed value could ever be negative or whether the unsigned value can fit within the constraints of a signed quantity. 738 Symbol 'Symbol' (Location) not explicitly initialized -- The named static local variable was not initialized before being passed to a function whose corresponding parameter is declared as pointer to const. Is this an error or is the programmer relying on the default initialization of 0 for all static items. By employing an explicit initializer you will suppress this message. See also message numbers 727 and 603. 739 Trigraph Sequence 'String' in literal (Quiet Change) -- The indicated Trigraph (three-character) sequence was found within a string. This trigraph reduces to a single character according to the ANSI standard. This represents a "Quiet Change" from the past where the sequence was not treated as exceptional. If you had no intention of mapping these characters into a single character you may precede the initial '?' with a backslash. If you are aware of the convention and you intend that the Trigraph be converted you should suppress this informational message. 740 Unusual pointer cast (incompatible indirect types) -- A cast is being made to convert one pointer to another such that neither of the pointers is a generic pointer (neither is pointer to char, unsigned char, or void) and the indirect types are truly different. The message will not be given if the indirect types differ merely in signedness (e.g., pointer to unsigned versus pointer to int) or in qualification (e.g., pointer to const int versus pointer to int). The message will also not be given if one of the indirect types is a union. The main purpose of this message is to report possible problems for machines in which pointer to char is rendered differently from pointer to word. Consider casting a pointer to pointer to char to a pointer to pointer to word. The indirect bit pattern remains unchanged. A second reason is to identify those pointer casts in which the indirect type doesn't seem to have the proper bit pattern such as casting from a pointer to int to a pointer to double. If you are not interested in running on machines in which char pointers are fundamentally different from other pointers then you may want to suppress this message. You can also suppress this message by first casting to char pointer or to void pointer but this is only recommended if the underlying semantics are right. 741 Unusual pointer cast (function qualification) -- A cast is being made between two pointers such that their indirect types differ in one of the Microsoft qualifiers: pascal, fortran, cdecl and interrupt. If this is not an error you may cast to a more neutral pointer first such as a void *. 742 Multiple character constant -- A character constant was found that contained multiple characters, e.g., 'ab'. This is legal C but the numeric value of the constant is implementation defined. It may be safe to suppress this message because, if more characters are provided than what can fit in an int, message number 25 is given. 743 Negative character constant -- A character constant was specified whose value is some negative integer. For example, on machines where a byte is 8 bits, the character constant '\xFF' is flagged because its value (according to the ANSI standard) is -1 (its type is int). Note that its value is not 0xFF. 744 switch statement has no default -- A switch statement has no section labeled default:. Was this an oversight? It is standard practice in many programming groups to always have a default: case. This can lead to better (and earlier) error detection. One way to suppress this message is by introducing a vacuous default: break; statement. If you think this adds too much overhead to your program, think again. In all cases tested so far, the introduction of this statement added absolutely nothing to the overall length of code. If you accompany the vacuous statement with a suitable comment, your code will at least be more readable. This message is not given if the control expression is an enumerated type. In this case, all enumerated constants are expected to be represented by case statements, else 787 will be issued. 745 function 'Name' has no explicit type or class, int assumed -- A function declaration or definition contained no explicit type. Was this deliberate? If the flag fdr (deduce return mode, see Section 5.5 Flag Options) is turned on, this message is suppressed. 746 call to function 'Name' not made in the presence of a prototype -- A call to a function is not made in the presence of a prototype. This does not mean that PC-lint/FlexeLint is unaware of any prototype; it means that a prototype is not in a position for a compiler to see it. If you have not adopted a strict prototyping convention you will want to suppress this message with -e746. 747 Significant prototype coercion (Context) Type to Type -- The type specified in the prototype differed from the type provided as an argument in some significant way. Usually the two types are arithmetic of differing sizes or one is float and the other integral. This is flagged because if the program were to be translated by a compiler that does not support prototype conversion, the conversion would not be performed. See also Section 17.6 C Elective Notes 917 and 918. 748 Symbol 'Symbol' (Location) is a register variable used with setjmp -- The named variable is a register variable and is used within a function that calls upon setjmp. When a subsequent longjmp is issued the values of register variables may be unpredictable. If this error is not sup pressed for this variable, the variable is marked as uninitialized at this point in the program. More information on messages 749-769 can be found in Section 11.8 Weak Definials. 749 local enumeration constant 'Symbol' (Location) not referenced -- A member (name provided as Symbol) of an enum was defined in a module but was not otherwise used within that module. A 'local' member is one that is not defined in a header file. Compare with messages 754 and 769. 750 local macro 'Symbol' (Location) not referenced -- A 'local' macro is one that is not defined in a header file. The macro is not referenced throughout the module in which it is defined. 751 local typedef 'Symbol' (Location) not referenced -- A 'local' typedef symbol is one that is not defined in any header file. It may have file scope or block scope but it was not used through its scope. 752 local declarator 'Symbol' (Location) not referenced -- A 'local' declarator symbol is one declared in a declaration appearing in the module file itself as opposed to a header file. The symbol may have file scope or may have block scope. But it wasn't referenced. 753 local struct, union or enum tag 'Symbol' (Location) not referenced -- A 'local' tag is one not defined in a header file. Since its definition appeared, why was it not used? Use of a tag is implied by the use of any of its members. 754 local structure member 'Symbol' (Location) not referenced -- A member (name provided as Symbol) of a struct or union was defined in a module but was not otherwise used within that module. A 'local' member is one that is not defined in a header file. See message 768. 755 global macro 'Symbol' (Location) not referenced -- A 'global' macro is one defined in a header file. This message is given for macros defined in non-library headers. The macro is not used in any of the modules comprising the program. This message is suppressed for unit checkout (-u option). See Section 11. 756 global typedef 'Symbol' (Location) not referenced -- This message is given for a typedef symbol declared in a non-library header file. The symbol is not used in any of the modules comprising a program. This message is suppressed for unit checkout (-u option). 757 global declarator 'Symbol' (Location) not referenced -- This message is given for objects that have been declared in non-library header files and that have not been used in any module comprising the program being checked. The message is suppressed for unit checkout (-u). 758 global struct, union or enum tag 'Symbol' (Location) not referenced -- This message is given for struct, union and enum tags that have been defined in non-library header files and that have not been used in any module comprising the program. The message is suppressed for unit checkout (-u). 759 header declaration for symbol 'Symbol' (Location) could be moved from header to module -- This message is given for declarations, within non-library header files, that are not referenced outside the defining module. Hence, it can be moved inside the module and thereby 'lighten the load' on all modules using the header. This message is only given when more than one module is being linted. 760 Redundant macro 'Symbol' defined identically at Location -- The given macro was defined earlier (location given) in the same way and is hence redundant. 761 Redundant typedef 'Symbol' previously declared at Location -- A typedef symbol has been typedefed earlier at the given location. Although the declarations are consistent you should probably remove the second. 762 Redundantly declared symbol 'Symbol' previously declared at Location -- A declaration for the given symbol was found to be consistent with an earlier declaration in the same scope. This declaration adds nothing new and it can be removed. 763 Redundant declaration for symbol 'Symbol' previously declared at Location -- A tag for a struct, union or enum was defined twice in the same module (consistently). The second one can be removed. 764 switch statement does not have a case -- A switch statement has been found that does not have a case statement associated with it (it may or may not have a default statement). This is normally a useless construct. 765 external 'Symbol' (Location) could be made static -- An external symbol was referenced in only one module. It was not declared static (and its type is not qualified with the Microsoft keyword __export). Some programmers like to make static every symbol they can, because this lightens the load on the linker. It also represents good documentation. On the other hand, you may want the symbol to remain external because debuggers often work only on external names. It's possible, using macros, to have the best of both worlds; see Section 11.8.3 staticable. 766 Include of header file FileName not used in module String -- The named header file was directly #include'd in the named module but the #include can be removed because it was not used in processing the named module or in any header included by the module. It contained no macro, typedef, struct, union or enum tag or component, or declaration referenced by the module. One of the reasons a particular #include can be removed is because it had been included by an earlier header file. Warning 537 can be used to detect such cases. See also Info messages 964, 966 and Section 11.8.1 Unused Headers. 767 macro 'Symbol' was defined differently in another module (Location) -- Two macros processed in two different modules had inconsistent definitions. 768 global struct member 'Symbol' (Location) not referenced -- A member (name provided as Symbol) of a struct or union appeared in a non-library header file but was not used in any module comprising the program. This message is suppressed for unit checkout. Since struct's may be replicated in storage, finding an unused member can pay handsome storage dividends. However, many structures merely reflect an agreed upon convention for accessing storage and for any one program many members are unused. In this case, receiving this message can be a nuisance. One convenient way to avoid unwanted messages (other than the usual -e and -esym) is to always place such structures in library header files. Alternatively, you can place the struct within a ++flb ... --flb sandwich to force it to be considered library. 769 global enumeration constant 'Symbol' (Location) not referenced -- A member (name provided as Symbol) of an enum appeared in a non-library header file but was not used in any module comprising the program. This message is suppressed for unit checkout. There are reasons why a programmer may occasionally want to retain an unused enum and for this reason this message is distinguished from 768 (unused member). See message 768 for ways of selectively suppressing this message. 770 tag 'Symbol' defined identically at Location -- The struct, union, or enum tag Symbol was defined identically in different locations (usually two different files). This is not an error but it is not necessarily good programming practice either. It is better to place common definitions of this kind in a header file where they can be shared among several modules. If you do this, you will not get this message. Note that if the tag is defined differently in different scopes, you will receive warning 631 rather than this message. 771 Symbol 'Symbol' (Location) conceivably not initialized -- The named symbol, declared at Location, was initialized in the main portion of a control loop (while, for, or do) and subsequently used outside the loop. If it is possible for the main body of the loop to not be fully executed, then the given symbol would remain uninitialized resulting in an error. PC-lint/FlexeLint does not do a great job of evaluating expressions and hence may not recognize that a loop is executed at least once. This is particularly true after initializing an array. Satisfy yourself that the loop is executed and then suppress the message. You may wish to suppress the message globally with -e771 or just for specific symbols using -esym. Don't forget that a simple assignment statement may be all that's needed to suppress the message. See Section 9. 772 Symbol 'Symbol' (Location) conceivably not initialized -- The address of the named Symbol was passed to a function expecting to receive a pointer to a const item. This requires the Symbol to have been initialized. See Warning 603 for an explanation of the dangers of such a construct. See Informational message 771 for an explanation of "conceivably not initialized." 773 Expression-like macro 'Symbol' not parenthesized -- A macro that appeared to be an expression contained unparenthesized binary operators and therefore may result in unexpected associations when used with other operators. For example, #define A B + 1 may be used later in the context: f( A * 2 ); with the surprising result that B+2 gets passed to f and not the (B+1)*2 Corrective action is to define A as: #define A (B + 1) Lowest precedence binary operators are not reported upon. Thus: #define A s.x does not elicit this message because this case does not seem to represent a problem. Also, unparenthesized unary operators (including casts) do not generate this message. Information about such unparenthesized parameters can be found by enabling Elective Note 973. [22 section 20.5] 774 Boolean within 'String' always evaluates to [True/False] -- The indicated clause (String is one of if, while or for (2nd expression)) has an argument that appears to always evaluate to either 'True' or 'False' (as indicated in the message). Information is gleaned from a variety of sources including prior assignment statements and initializers. Compare this with message 506, which is based on testing constants or combinations of constants. Also compare with the Elective Note 944, which can sometimes provide more detailed information. See Section 9. 775 non-negative quantity cannot be less than zero -- A non-negative quantity is being compared for being <=0. This is a little suspicious since a non-negative quantity can be equal to 0 but never less than 0. The non-negative quantity may be of type unsigned or may have been promoted from an unsigned type or may have been judged not to have a sign by virtue of it having been AND'ed with a quantity known not to have a sign bit an enum that may not be negative, etc. See also Warning 568. 776 Possible truncation of addition -- An int expression (signed or unsigned) involving addition or subtraction is converted to long implicitly or explicitly. Moreover, the precision of a long is greater than that of int. If an overflow occurred, information would be lost. Either cast one of the operands to some form of long or cast the result to some form of int. See Warning 647 for a further description and an example of this kind of error. See also messages 790 and 942. 777 Testing float's for equality -- This message is issued when the operands of operators == and != are some form of floating type (float, double, or long double). Testing for equality between two floating point quantities is suspect because of round-off error and the lack of perfect representation of fractions. If your numerical algorithm calls for such testing turn the message off. The message is suppressed when one of the operands can be represented exactly, such as 0 or 13.5. 778 Constant expression evaluates to 0 in operation: String -- A constant expression involving addition, subtraction, multiplication, shifting, or negation resulted in a 0. This could be a purposeful computation but could also have been unintended. If this is intentional, suppress the message. If one of the operands is 0, Elective Note 941 may be issued rather than a 778. 779 String constant in comparison operator: Operator -- A string constant appeared as an argument to a comparison operator. For example: if( s == "abc" ) ... This is usually an error. Did the programmer intend to use strcmp? It certainly looks suspicious. At the very least, any such comparison is bound to be machine-dependent. If you cast the string constant, the message is suppressed. 780 Vacuous array element -- A declaration of an array looks suspicious because the array element is an array of 0 dimension. For example: extern int a[][]; extern int a[10][]; will both emit this message but extern int a[][10]; will not. In the latter case, proper array accessing will take place even though the outermost dimension is missing. If extern were omitted, the construct would be given a more serious error message. 781 Inconsistent use of tag 'Symbol' conflicts with Location -- A tag specified as a union, struct, or enum was specified as some other type in another module (location given by Location). For example, if tag is specified as union in one module and is specified as struct in the current module you will get this message. See also Warning 407. 782 Line exceeds Integer characters -- An internal limit on the size of the input buffer has been reached. The message contains the maximum permissible size. This does not necessarily mean that the input will be processed erroneously. Additional characters will be read on a subsequent read. However the line sequence numbers reported on messages will be incorrect. 783 Line does not end with new-line -- This message is issued when an input line is not terminated by a new-line or when a NUL character appears within an input line. When input lines are read, an fgets is used. A strlen call is made to determine the number of characters read. If the new-line character is not seen at the presumed end, this message is issued. If your editor is in the habit of not appending new-lines onto the end of the last line of the file then suppress this message. Otherwise, examine the file for NUL characters and eliminate them. 784 Nul character truncated from string -- During initialization of an array with a string constant there was not enough room to hold the trailing NUL character. For example: char a[3] = "abc"; would evoke such a message. This may not be an error since the easiest way to do this initialization is in the manner indicated. It is more convenient than: char a[3] = { 'a', 'b', 'c' }; On the other hand, if it really is an error it may be especially difficult to find. 785 Too few initializers for aggregate -- The number of initializers in a brace-enclosed initializer was less than the number of items in the aggregate. Default initialization is taken. An exception is made with the initializer {0}. This is given a separate message number in the Elective Note category ( 943). It is normally considered to be simply a stylized way of initializing all members to 0. 786 String concatenation within initializer -- Although it is perfectly 'legal' to concatenate string constants within an initializer, this is a frequent source of error. Consider: char *s[] = { "abc" "def" }; Did the programmer intend to have an array of two strings but forget the comma separator? Or was a single string intended? 787 enum constant 'Symbol' not used within switch -- A switch expression is an enumerated type and at least one of the enumerated constants was not present as a case label. Moreover, no default case was provided. 788 enum constant 'Symbol' not used within defaulted switch -- A switch expression is an enumerated type and at least one of the enumerated constants was not present as a case label. However, unlike Info 787, a default case was provided. This is a mild form of the case reported by Info 787. The user may thus elect to inhibit this mild form while retaining Info 787. 789 Assigning address of auto variable 'Symbol' to static -- The address of an auto variable (Symbol) is being assigned to a static variable. This is dangerous because the static variable will persist after return from the function in which the auto is declared but the auto will be, in theory, gone. This can prove to be among the hardest bugs to find. If you have one of these, make cer tain there is no error and use -esym to suppress the message for a particular variable. 790 Suspicious truncation, integral to float -- This message is issued when it appears that there may have been an unintended loss of information during an operation involving integrals, the result of which is later converted to a floating point quantity. The operations that are scrutinized and reported upon by this message are: shift left and multiplication. Addition and subtraction are covered by Elective Note 942. See also messages 647 and 776. 791 unusual option sequence -- A temporary message suppression option (one having the form: !e...) followed a regular option. Was this intended? 792 void cast of void expression -- A void expression has been cast to void. Was this intended? 793 ANSI limit of 'String' 'Name' exceeded -- Some ANSI limit has been exceeded. These limits are described in Section 2.2.4.1 of the ANSI C Standard. Programs exceeding these limits are not considered maximally portable. However, they may work for individual compilers. Many large programs exceed the ANSI limit of 511 external identifiers. This will result in message 793 "ANSI limit of 511 'external identifiers' exceeded". It may not be obvious how to inhibit this message for identifiers while leaving other limits in a reportable state. The second parameter of the message is designated Name and so the -esym may be used. Because the symbol contains a blank, quotes must be used. The option becomes: -"esym(793,external identifiers)" 794 Conceivable use of null pointer 'Symbol' in [left/right] argument to operator 'String' Reference -- From information gleaned from earlier statements it is conceivable that a null pointer (a pointer whose value is 0) can be used in a context where null pointers are inappropriate. In the case of binary operators one of the words 'left' or 'right' is used to designate which operand is null. Symbol identifies the pointer variable that may be NULL. This is similar to messages 413 and 613 and differs from them in that the likelihood is not as great. For example: int *p = 0; int i; for( i = 0; i < n; i++ ) p = &a[i]; *p = 0; If the body of the for loop is never taken then p remains null. 795 Conceivable division by 0 -- In a division or modulus operation the division is deduced to be conceivably 0. See Section 9.2 Value Tracking for the meaning of "conceivable". 796 Conceivable access of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer may conceivably have been accessed. See message 415 for a description of the parameters Integer and String. For example: int a[10]; int j = 100; for( i = 0; i < n; i++ ) j = n; a[j] = 0; Here, the access to a[j] is flagged because it is conceivable that the for loop is not executed leaving the unacceptable index of 100 in variable j. This message is similar to messages 415 and 661 but differing from them by the degree of probability. 797 Conceivable creation of out-of-bounds pointer ('Integer' beyond end of data) by operator 'String' -- An out-of-bounds pointer is potentially being created. See message 415 for a description of the parameters Integer and String. See message 796 for an example of how a probability can be considered 'conceivable'. See also message 416 and/or Section 9.2 Value Tracking) for a description of the difference between pointer 'creation' and pointer 'access'. 798 Redundant character 'Char' -- The indicated character char is redundant and can be eliminated from the input source. A typical example is a backslash on a line by itself. 799 numerical constant 'Integer' larger than unsigned long -- An integral constant was found to be larger than the largest value allowed for unsigned long quantities. By default, an unsigned long is 4 bytes but can be respecified via the option -sl#. If the long long type is permitted (see option +fll) this message is automatically suppressed. See also message 417. 801 Use of goto is deprecated -- A goto was detected. Use of the goto is not considered good programming practice by most authors and its use is normally discouraged. There are a few cases where the goto can be effectively employed but often these can be rewritten just as effectively without the goto. The use of goto's can have a devastating effect on the structure of large functions creating a mass of spaghetti-like confusion. For this reason its use has been banned in many venues. 802 Conceivably passing a null pointer to function 'Symbol', Context Reference -- A NULL pointer is conceivably being passed to a function identified by Symbol. The argument in question is given by Context. The function is either a library function designed not to receive a NULL pointer or a user function dubbed so via the option -function. See Section 10. See Section 9.2 Value Tracking for the meaning of 'conceivable'. 803 Conceivable data overrun for function 'Symbol', argument Integer exceeds argument Integer Reference -- This message is for data transfer functions such as memcpy, strcpy, fgets, etc. when the size indicated by the first cited argument (or arguments) can conceivably exceed the size of the buffer area cited by the second. The message may also be issued for user functions via the -function option. See Section 10. See Section 9.2 Value Tracking for the meaning of 'conceivable'. 804 Conceivable access beyond array for function 'Symbol', argument Integer exceeds Integer Reference -- This message is issued for several library functions (such as fwrite, memcmp, etc) wherein there is conceivably an attempt to access more data than exist. For example, if the length of data specified in the fwrite call can exceed the size of the data specified. The function is specified by Symbol and the arguments are identified by argument number. See also Section 10.1 Function Mimicry (function) and Section 9.2 Value Tracking. 805 Expected L"..." to initialize wide char string -- An initializer for a wide character array or pointer did not use a preceding 'L'. For example: wchar_t a[] = "abc"; was found whereas wchar_t a[] = L"abc": was expected. 806 Small bit field is signed rather than unsigned -- A small bit field (less than an int wide) was found and the base type is signed rather than unsigned. Since the most significant bit is a sign bit this practice can produce surprising results. For example, struct { int b:1; } s; s.b = 1; if( s.b > 0 ) /* should succeed but actually fails */ ... 807 Conceivably passing to function 'Symbol' a negative value (Integer), Context Reference -- An integral value that may conceivably be negative is being passed to a function that is expecting only positive values for a particular argument. The message contains the name of the function (Symbol), the questionable value (Integer) and the argument number (Context). The function may be a standard library function designed to accept only positive values such as malloc or memcpy (third argument), or may have been identified by the user as such through the -function or -sem options. See message 422 for an example and further explanation. 808 No explicit type given symbol 'Symbol' given, assumed int -- An explicit type was missing in a declaration. Unlike Warning 601, the declaration may have been accompanied by a storage class or modifier (qualifier) or both. For example: extern f(void); will draw message 808. Had the extern not been present, a 601 would have been raised. The keywords unsigned, signed, short and long are taken to be explicit type specifiers even though int is implicitly assumed as a base. 809 Possible return of address of auto through variable 'Symbol' -- The value held by a pointer variable may have been the address of an auto variable. It is normally incorrect to return the address of an item on the stack because the portion of the stack allocated to the returning function is subject to being obliterated after return. 810 Arithmetic modification of custodial variable 'Symbol' -- We define the custodial variable as that variable directly receiving the result of a malloc or new or equivalent call. It is inappropriate to modify such a variable because it must ultimately be free'ed or delete'ed. You should first make a copy of the custodial pointer and then modify the copy. The copy is known as an alias. 811 Possible deallocation of pointer alias -- A free or a delete was applied to a pointer that did not appear to be the custodial variable of the storage that had been allocated. Please refer to message 810 for the definition of 'custodial variable'. Deleting an alias pointer is bad because it can result in deleting the same area twice. This can cause strange behavior at unpredictable times. Always try to identify the custodial pointer as opposed to copies (or aliases) of it. Then deallocate storage through the custodial pointer. Modify only the alias pointers. 812 static variable 'Symbol' has size 'Integer' -- The amount of storage for a static symbol has reached or exceeded a value that was specified in a -size option ( See Section 5.). 813 auto variable 'Symbol' in function 'Symbol' has size 'Integer' -- The amount of storage for an auto symbol has reached or exceeded a value that was specified in a -size option ( See Section 5.). 815 Arithmetic modification of unsaved pointer -- An allocation expression (malloc, calloc, new) is not immediately assigned to a variable but is used as an operand in some expression. This would make it difficult to free the allocated storage. For example: p = new X[n] + 2; will elicit this message. A preferred sequence is: q = new X[n]; p = q+2; In this way the storage may be freed via the custodial pointer q. Another example of a statement that will yield this message is: p = new (char *) [n]; This is a gruesome blunder on the part of the programmer. It does NOT allocate an array of pointers as a novice might think. It is parsed as: p = (new (char *)) [n]; which represents an allocation of a single pointer followed by an index into this 'array' of one pointer. 816 Non-ANSI format specification -- A non-standard format specifier was found in a format-processing function such as printf or scanf. Such a specifier could be unique to a particular compiler or could be a de facto standard but is not ANSI. 817 Conceivably negative subscript (Integer) in operator 'String' -- An integer whose value was conceivably negative was added to an array or to a pointer to an allocated area (allocated by malloc, operator new, etc.) This message is not given for pointers whose origin is unknown since a negative subscript is in general legal. The addition could have occurred as part of a subscript operation or as part of a pointer arithmetic operation. The operator is denoted by String. The value of the integer is given by Integer. 818 Pointer parameter 'Symbol' (Location) could be declared ptr to const -- As an example: int f( int *p ) { return *p; } can be redeclared as: int f( const int *p ) { return *p; } Declaring a parameter a pointer to const offers advantages that a mere pointer does not. In particular, you can pass to such a parameter the address of a const data item. In addition it can offer better documentation. Other situations in which a const can be added to a declaration are covered in messages 952, 953, 954 and 1764. 820 Boolean test of a parenthesized assignment -- A Boolean test was made on the result of an assignment and, moreover, the assignment was parenthesized. For example: if ( (a = b) ) ... // Info 820 will draw this informational whereas if ( a = b ) ... // Info 720 (i.e. the unparenthesized case) will, instead, draw Info 720. We, of course, do not count the outer parentheses, required by the language, that always accompany the if clause. The reason for partitioning the messages in this fashion is to allow the programmer to adopt the convention, advanced by some compilers (in particular gcc), of always placing a redundant set of parentheses around any assignment that is to be tested. In this case you can suppress Info 820 (via -e820) while still enabling Info 720. 821 Right hand side of assignment not parenthesized -- An assignment operator was found having one of the following forms: a = b || c a = b && c a = b ? c : d Moreover, the assignment appeared in a context where a value was being obtained. For example: f( a = b ? c : d ); The reader of such code could easily confuse the assignment for a test for equality. To eliminate any such doubts we suggest parenthesizing the right hand side as in: f( a = (b ? c : d) ); 825 control flows into case/default without -fallthrough comment -- A common programming mistake is to forget a break statement between case statements of a switch. For example: case 'a': a = 0; case 'b': a++; Is the fall through deliberate or is this a bug? To signal that this is intentional use the -fallthrough option within a lint comment as in: case 'a': a = 0; //lint -fallthrough case 'b': a++; This message is similar to Warning 616 ("control flows into case/default") and is intended to provide a stricter alternative. Warning 616 is suppressed by any comment appearing at the point of the fallthrough. Thus, an accidental omission of a break can go undetected by the insertion of a neutral comment. This can be hazardous to well-commented programs. 826 Suspicious pointer-to-pointer conversion (area too small) -- A pointer was converted into another either implicitly or explicitly. The area pointed to by the destination pointer is larger than the area that was designated by the source pointer. For example: long *f( char *p ) { return (long *) p; } 827 Loop not reachable -- A loop structure (for, while, or do) could not be reached. Was this an oversight? It may be that the body of the loop has a labeled statement and that the plan of the programmer is to jump into the middle of the loop through that label. It is for this reason that we give an Informational message and not the Warning ( 527) that we would normally deliver for an unreachable statement. But please note that jumping into a loop is a questionable practice in any regard. 828 Semantics of function 'Name' copied to function 'Name' -- A function with built-in semantics or user-defined semantics was #define'd to be some other function with a similar name formed by prepending or appending underscores. For example: #define strcmp(a,b) __strcmp__(a,b) will cause Info 828 to be issued. As the message indicates, the semantics will be automatically transferred to the new function. 829 A +headerwarn option was previously issued for header 'Symbol' -- Some coding standards discourage or even prohibit the use of certain header files. PC-lint can guard against their use if we by activating the lint option +headerwarn(Symbol). Later, if the file is used, we will then issue this message. 830 Location cited in prior message -- Message 830 is a vehicle to convey in 'canonical form' the location information embedded within some other message. For example, consider the (somewhat simplified) message: file x.c line 37: Declaration for 'x' conflicts with line 22 This contains the location ("line 22") embedded in the text of the message. Embedded location information is not normally understood by editors and IDE's (Interactive Development Environments), which can only position to the nominal location (line 37 in this example). By adding this additional message with the nominal location of line 22 the user can, by stepping to the next message, see what the 'conflict' is all about. 831 Reference cited in prior message -- Message 831 is similar to message 830 in that it is a vehicle to convey in 'canonical form' location information embedded within some other message. In the case of Info 831 the information is Reference information. This is a sequence of 1 or more locations that support a particular message. For example, consider the (somewhat simplified) message: file y.c line 701: Possible divide by 0 [Reference: file z.c lines 22, 23] Accompanying this message will be two Info 831 messages, one for each of the references cited in the message. Without this it would be a relatively tedious matter to locate each one of the references to determine just why there is a potential divide by 0. With these additional messages, editors and IDE's can automatically position the focus of editing to the nominal locations of the message. 832 Parameter 'Symbol' not explicitly declared, int assumed -- In an old-style function definition a parameter was not explicitly declared. To illustrate: void f( n, m ) int n; { ... This is an example of an old-style function definition with n and m the parameters. n is explicitly declared and m is allowed to default to int. An 832 will be issued for m. 833 Symbol 'Symbol' is typed differently (String) in another module, compare with Location -- Two objects, functions or definials are typed differently in two different modules. This is a case where the difference is legal but may cause confusion on the part of program maintenance. 834 Operator 'Name' followed by operator 'Name' is confusing. Use parentheses. -- Some combinations of operators seem to be confusing. For example: a = b - c - d; a = b - c + d; a = b / c / d; a = b / c * d; tend to befuddle the reader. To reduce confusion we recommend using parentheses to make the association of these operators explicit. For example: a = (b - c) - d; a = (b - c) + d; a = (b / c) / d; a = (b / c) * d; in place of the above. 17.6 C Elective Notes Messages in the 900 level are termed "elective" because they are not normally on. They must be explicitly turned on with an option of the form +e9... or -w4. Messages in the range 910-919 involve implicit conversions. Messages in the range 920-930 involve explicit conversions (casts). 900 Successful completion, 'Integer' messages produced -- This message exists to provide some way of ensuring that an output message is always produced, even if there are no other messages. This is required for some windowing systems. For this purpose use the option +e900. 909 Implicit conversion from Type to bool -- A non-bool was tested as a Boolean. For example, in the following function: int f(int n) { if( n ) return n; else return 0; } the programmer tests 'n' directly rather than using an explicit Boolean expression such as 'n != 0'. Some shops prefer the explicit test. 910 Implicit conversion (Context) from 0 to pointer -- A pointer was assigned (or initialized) with a 0. Some programmers prefer other conventions such as NULL or nil. This message will help such programmers root out cavalier uses of 0. This is relatively easy in C since you can define NULL as follows: #define NULL (void *)0 However, in C++, a void* cannot be assigned to other pointers without a cast. Instead, assuming that NULL is defined to be 0, use the option: --emacro((910),NULL) This will inhibit message 910 in expressions using NULL. This method will also work in C. Both methods assume that you expressly turn on this message with a +e910 or equivalent. 911 Implicit expression promotion from Type to Type -- Notes whenever a sub-integer expression such as a char, short, enum, or bit-field is promoted to int for the purpose of participating in some arithmetic operation or function call. 912 Implicit binary conversion from Type to Type -- Notes whenever a binary operation (other than assignment) requires a type balancing. A smaller range type is promoted to a larger range type. For example: 3 + 5.5 will trigger such a message because int is converted to double. 913 Implicit adjustment of expected argument type from Type to Type -- Notes whenever an old-style function definition contains a sub-integer or float type. For example: int f( ch, x ) char ch; float x; { ... contains two 913 adjustments. 914 Implicit adjustment of function return value from Type to Type -- Notes whenever the function return value is implicitly adjusted. This message is given only for functions returning arrays. 915 Implicit conversion (Context) Type to Type -- Notes whenever an assignment, initialization or return implies an arithmetic conversion (Context specifies which). 916 Implicit pointer assignment conversion (Context) -- Notes whenever an assignment, initialization or return implies an implicit pointer conversion (Context specifies which). 917 Prototype coercion (Context) Type to Type -- Notes whenever an implicit arithmetic conversion takes place as the result of a prototype. For example: double sqrt(double); ... sqrt(3); ... will elicit this message because 3 is quietly converted to double. 918 Prototype coercion (Context) of pointers -- Notes whenever a pointer is implicitly converted because of a prototype. Because of prototype conversion, near pointers will otherwise be silently mapped into far pointers. far pointers mapped into near pointers also generate message 619. 919 Implicit conversion (Context) Type to Type -- A lower precision quantity was assigned to a higher precision variable as when an int is assigned to a double. 920 Cast from Type to void -- A cast is being made from the given type to void. 921 Cast from Type to Type -- A cast is being made from one integral type to another. 922 Cast from Type to Type -- A cast is being made to or from one of the floating types (float, double, long double). 923 Cast from Type to Type -- A cast is being made either from a pointer to a non-pointer or from a non-pointer to a pointer. 924 Cast from Type to Type -- A cast is being made from a struct or a union. If the cast is not to a compatible struct or union error 69 is issued. 925 Cast from pointer to pointer -- A cast is being made to convert one pointer to another such that one of the pointers is a pointer to void. Such conversions are considered harmless and normally do not even need a cast. 926 Cast from pointer to pointer -- A cast is being made to convert a char pointer to a char pointer (one or both of the char's may be unsigned). This is considered a 'safe' cast. 927 Cast from pointer to pointer -- A cast is being made to convert a char (or unsigned char) pointer to a non-char pointer. char pointers are sometimes implemented differently from other pointers and there could be an information loss in such a conversion. 928 Cast from pointer to pointer -- A cast is being made from a non-char pointer to a char pointer. This is generally considered to be a 'safe' conversion. 929 Cast from pointer to pointer -- A cast is being made to convert one pointer to another that does not fall into one of the classifications described in 925 through 928 above. This could be nonportable on machines that distinguish between pointer to char and pointer to word. Consider casting a pointer to pointer to char to a pointer to pointer to word. The indirect bit pattern remains unchanged. 930 Cast from Type to Type -- A cast is being made to or from an enumeration type. 931 Both sides have side effects -- Indicates when both sides of an expression have side-effects. An example is n++ + f(). This is normally benign. The really troublesome cases such as n++ + n are caught via Warning 564. 932 Passing near pointer to library function 'Symbol' (Context) -- A source of error in Windows programming is to pass a near pointer to a library function (See Chapter 6.). If the library is a DLL library, then in supplying the missing segment, the library would assume its own data segment, which would probably be wrong. See also messages 933 and 934. 933 Passing near pointer to far function (Context) -- A source of error in Windows programming is to pass a near pointer to a DLL function. Most Microsoft functions in DLLs are declared with the far modifier. Hence this can be tentatively used as a discriminant to decide that a pointer is too short. An advantage that this Note has over 932 is that it can catch functions designated only by pointer. Also you may be using libraries that are not DLLs and that share the same DS segment. In this case, 932 may produce too many superfluous messages. See also message 934. 934 taking address of near auto variable 'Symbol' (Context) -- A source of error in writing DLL libraries is that the stack segment may be different from the data segment. In taking the address of a near data object only the offset is obtained. In supplying the missing segment, the compiler would assume the data segment, which could be wrong. See also messages 932 and 933. 935 int within struct -- This Note helps to locate non-portable data items within struct's. If instead of containing int's and unsigned int's, a struct were to contain short's and long's then the data would be more portable across machines and memory models. Note that bit fields and union's do not get complaints. 936 old-style function definition for function 'Symbol' -- An "old-style" function definition is one in which the types are not included between parentheses. Only names are provided between parentheses with the type information following the right parenthesis. This is the only style allowed by K&R. 937 old-style function declaration for function 'Symbol' -- An "old-style" function declaration is one without type information for its arguments. 938 parameter 'Symbol' not explicitly declared -- In an "old-style" function definition it is possible to let a function parameter default to int by simply not providing a separate declaration for it. 939 return type defaults to int for function 'Symbol' -- A function was declared without an explicit return type. If no explicit storage class is given, then Informational 745 is also given provided the Deduce Return mode flag (fdr) is off. This is meant to catch all cases. 940 omitted braces within an initializer -- An initializer for a subaggregate does not have braces. For example: int a[2][2] = { 1, 2, 3, 4 }; This is legal C but may violate local programming standards. The worst violations are covered by Warning 651. 941 Result 0 due to operand(s) equaling 0 in operation 'String' -- The result of a constant evaluation is 0 owing to one of the operands of a binary operation being 0. This is less severe than Info 778 wherein neither operand is 0. For example, expression (2&1) yields a 778 whereas expression (2&0) yields a 941. 942 Possibly truncated addition promoted to float -- An integral expression (signed or unsigned) involving addition or subtraction is converted to a floating point number. If an overflow occurred, information would be lost. See also messages 647, 776 and 790. 943 Too few initializers for aggregate -- The initializer {0} was used to initialize an aggregate of more than one item. Since this is a very common thing to do it is given a separate message number, which is normally suppressed. See 785 for more flagrant abuses. 944 [left/right/] argument for operator 'String' always evaluates to [True/False] -- The indicated operator (given by String has an argument that appears to always evaluate to either 'True' or 'False' (as indicated in the message). This is given for Boolean operators (||and && and for Unary operator !) and information is gleaned from a variety of sources including prior assignment statements and initializers. Compare this with message 506, which is based on testing constants or combinations of constants. 945 Undefined struct used with extern -- Some compilers refuse to process declarations of the form: extern struct X s; where struct X is not yet defined. This note can alert a programmer porting to such platforms. 946 Relational or subtract operator applied to pointers -- A relational operator (one of >, >=, <, <=) or the subtract operator has been applied to a pair of pointers. The reason this is of note is that when large model pointers are compared (in one of the four ways above) or subtracted, only the offset portion of the pointers is subject to the arithmetic. It is presumed that the segment portion is the same. If this presumption is not accurate then disaster looms. By enabling this message you can focus in on the potential trouble spots. 947 Subtract operator applied to pointers -- An expression of the form p - q was found where both p and q are pointers. This is of special importance in cases where the maximum pointer can overflow the type that holds pointer differences. For example, suppose that the maximum pointer is 3 Gigabytes -1, and that pointer differences are represented by a long, where the maximum long is 2 Gigabytes -1. Note that both of these quantities fit within a 32 bit word. Then subtracting a small pointer from a very large pointer will produce an apparent negative value in the long representing the pointer difference. Conversely, subtracting a very large pointer from a small pointer can produce a positive quantity. The alert reader will note that a potential problem exists whenever the size of the type of a pointer difference equals the size of a pointer. But the problem doesn't usually manifest itself since the highest pointer values are usually less than what a pointer could theoretically hold. For this reason, the message cannot be given automatically based on scalar types and hence has been made an Elective Note. Compare this Note with that of 946, which was designed for a slightly different pointer difference problem. 950 Non-ISO/ANSI reserved word or construct: 'Symbol' -- Symbol is either a reserved word that is non-ISO/ANSI or a construct (such as the // form of comment in a C module). This Elective Note is enabled automatically by the -A option. If these messages are occurring in a compiler or library header file over which you have no control, you may want to use the option -elib(950). If the reserved word is one you want to completely disable, then use the option -rw(Word). 951 Pointer to incomplete type 'Symbol' employed in operation -- A pointer to an incomplete type (for example, struct X where struct X has not yet been defined in the current module) was employed in an assignment or in a comparison (for equality) operator. For example, suppose a module consisted only of the following function: struct A * f(struct A *p ) { return p; } Since struct A had not been defined, this message will be issued. Such employment is permitted by the standard but is not permitted by all C compilers. If you want to deploy your application to the maximum number of platforms you should enable this Elective Note. 952 Parameter 'Symbol' (Location) could be declared const -- A parameter is not modified by a function. For example: int f( char *p, int n ) { return *p = n; } can be redeclared as: int f( char * const p, const int n ) { return *p = n; } There are few advantages to declaring an unchanging parameter a const. It signals to the person reading the code that a parameter is unchanging, but, in the estimate of most, reduces legibility. For this reason the message has been given an Elective Note status. However, there is a style of programming that encourages declaring parameters const. For the above example, this style would declare f as int f( char * p, int n); and would use the const qualifier only in the definition. Note that the two forms are compatible according to the standard. The declaration is considered the interface specification where const does not matter. The const's do matter in the definition of the function, which is considered the implementation. Message 952 could be used to support this style. Marking a parameter as const does not affect the type of argument that can be passed to the parameter. In particular, it does not mean that only const arguments may be passed. This is in contrast to declaring a parameter as pointer to const or reference to const. For these situations, Informational messages are issued ( 818 and 1764 respectively) and these do affect the kinds of arguments that may be passed. See also messages 953 and 954. 953 Variable 'Symbol' (Location) could be declared as const -- A local variable (either static or auto) is initialized but never modified thereafter. Such a variable could be declared const. One advantage in making such a declaration is that it can furnish a clue to the program reader that the variable is unchanging. In the case of static data it can mean that the data is ROM'able. Other situations in which a const can be added to a declaration are covered in messages 818, 952, 954 and 1764. 954 Pointer variable 'Symbol' (Location) could be declared as pointing to a const -- The data pointed to by a pointer is never changed (at least not through that pointer). It may therefore be better, or at least more descriptive, if the variable were typed pointer to const. For example: { char *p = "abc"; for( ; *p; p++ ) print(*p); } can be redeclared as: { const char *p = "abc"; for( ; *p; p++ ) print(*p); } It is interesting to contrast this situation with that of pointer parameters. The latter is given Informational status ( 818) because it has an effect of enhancing the set of pointers that can be passed into a function. Other situations in which a const can be added to a declaration are covered in messages 952, 953 and 1764. 955 Parameter name missing from prototype for function 'Symbol' -- In a function declaration a parameter name is missing. For example: void f(int); will raise this message. This is perfectly legal but misses an opportunity to instruct the user of a library routine on the nature of the parameter. For example: void f(int count); would presumably be more meaningful. [27, Rule 34]. This message is not given for function definitions, only function declarations. 956 Non const, non volatile static or external variable 'Symbol' -- This check has been advocated by programmers whose applications are multi-threaded. Software that contains modifiable data of static duration is often non-reentrant. That is, two or more threads cannot run the code concurrently. By 'static duration' we mean variables declared static or variables declared external to any function. For example: int count = 0; void bump() { count++; } void get_count() { return count; } If the purpose is to obtain a count of all the bump()'s by a given thread then this program clearly will not do since the global variable count sums up the bump()'s from all the threads. Moreover, if the purpose of the code is to obtain a count of all bump()'s by all threads, it still may contain a subtle error (depending on the compiler and the machine). If it is possible to interrupt a thread between the access of count and the subsequent store, then two threads that are bump()'ing at the same time, may register an increase in the count by just one. Please note that not all code is intended to be re-entrant. In fact most programs are not designed that way and so this Elective Note need not be enabled for the majority of programs. If the program is intended to be re-entrant, all uses of non-const static variables should be examined carefully for non-reentrant properties. 957 Function 'Symbol' defined without a prototype in scope -- A function was defined without a prototype in scope. It is usually good practice to declare prototypes for all functions in header files and have those header files checked against the definitions of the function to assure that they match. If you are linting all the files of your project together such cross checking will be done in the natural course of things. For this reason this message has been given a relatively low urgency of Elective Note. 958 Padding of Integer byte(s) is required to align member on Integer byte boundary -- This message is given whenever padding is necessary within a struct to achieve a required member alignment. Consider: struct A { char c; int n; }; Assuming that int must be aligned on a 4-byte boundary and assuming the size of a char to be 1, then this message will be issued indicating that there will be a padding of 3 bytes. The alignment requirements vary with the compiler, the machine and, sometimes, compiler options. When separately compiled programs need to share data at the binary level it helps to remove any artificially created padding from any of the structures that may be shared. 959 struct size (Integer bytes) is not an even multiple of the maximum member alignment (Integer bytes) -- The alignment of a structure (or union) is equal to the maximum alignment of any of its members. When an array of structures is allocated, the compiler ensures that each structure is allocated at an address with the proper alignment. This will require padding if the size of the structure is not an even multiple of its maximum alignment. For example: struct A { int n; char ch; } a[10]; Assuming the size and alignment of int is 4 then the size of each struct is 5 but its alignment is 4. As a result each struct in the array will be padded with 3 bytes. Alignment can vary with the compiler and the machine. If binary data is to be shared by separately compiled modules, it is safer to make sure that all shared structures and unions are explicitly padded. 960 Violates MISRA Required Rule Name, String -- MISRA is the "Guidelines for the use of the C Language in Vehicle Based Software". You may disable individual rules to your taste by using the Rule number in an esym option. For example: -esym( 960, 75, 8? ) will suppress MISRA rules 75 and any of those between 80 and 89 inclusive that are issued as the result of a message 960. See [10] for information on the MISRA guidelines. 961 Violates MISRA Advisory Rule Name, String -- This message is issued when a violation of the MISRA advisory guidelines is detected. See also Message 960. 964 Header file FileName not directly used in module String -- The given header file was not used in the given module, however it, itself, included a header file (possibly indirectly) that was used. An example of this is os2.h that is an umbrella header serving only to include other headers. Compare this message with 766. See also the discussion in Section 11.8.1 Unused Headers. 966 Indirectly included header file 'FileName' not used in module 'String' -- The header file given by FileName was unused directly or indirectly in a given module outside of its group. It was not, however, directly included by the module and so may not easily be excluded without disturbing the header including it. Since this header may be included in other places caution is advised. This message is a weaker version of 766. See the discussion in Section 11.8.1 Unused Headers. See also message 964. 970 Use of modifier or type 'Name' outside of a typedef -- Some standards require the use of type names (defined in typedef's) in preference to raw names used within the text of the program. For example they may want you to use INT32 rather than int where INT32 is defined as: typedef int INT32; This message is normally issued for the standard intrinsic types: bool, char, wchar_t, int, float, double, and for modifiers unsigned, signed, short and long. You may enable this message and then suppress the message for individual types to obtain special effects. For example the following will enable the message for all but bool. +e970 -esym(970,bool) 971 Use of 'char' without 'signed' or 'unsigned' -- The 'char' type was specified without an explicit modifier to indicate whether the char was signed or unsigned. The plain char type can be regarded by the compiler as identifying a signed or an unsigned quantity, whichever is more efficient to implement. Because of this ambiguity, some standards do not like the use of char without an explicit modifier to indicate its signedness. 973 Unary operator in macro 'Symbol' not parenthesized -- A unary operator appearing in an expression-like macro was found to be not parenthesized. For example: #define N -1 The user may prefer to parenthesize such things as: #define N (-1) This has been placed in the elective note category because we cannot find an instance when this really produces a problem. The important case of unparenthesized binary operators is covered with message 773. 17.7 C++ Syntax Errors 1001 Scope 'Name' must be a struct or class name -- In an expression of the form X::Y, X must be a class name. [11 section 10.4] 1002 'this' must be used in class member function -- The keyword this refers to the class being passed implicitly to a member function. It is invalid outside a class member function. [11 section 5.1] 1003 'this' may not be used in a static member function -- A static member function receives no this pointer. [11 section 9.4] 1004 Expected a pointer to member after .* or ->* -- The .* and ->* operators require pointer to members on the right hand side. [11 section 5.5] 1005 Destructor declaration requires class -- While expecting a declaration a '~' character was encountered. This was presumed to be the start of a destructor. However no class was specified. [11 section 12.4] 1006 Language feature 'String' not supported -- The indicated feature, while not supported in the current version, will hopefully be supported in future versions of the product. 1007 Pure specifier for function 'Symbol' requires a virtual function -- An '=' was found after a declaration. Was this the start of a pure specifier? The declaration was not that of a member function, which it must be. Also, the member function should be virtual. [11 section 10.3] 1008 Expected '0' to follow '=', text ignored -- Some nonstandard extensions to C++ allow integers to follow '=' for declarations of member functions. If you are using such extensions simply suppress this message. If only library headers are using this extension use -elib(1008). [11 section 10.3] 1009 operator String not redefinable -- The cited operator, one of '.*', '?', '::' or '.', may not be overloaded. [11 section 13.4] 1010 Expected a type or an operator -- Following the keyword operator the parser expected either an operator (including new, delete, (), [], comma) or a type. [11 sections 13.4 and 12.3.2] 1011 Conversion Type Name too long -- An upper limit of 50 characters has been reached on a conversion type name. 1012 Type not needed before 'operator type' -- The return type of a function introduced with 'operator Type' is Type and may not be preceded with the same or any other Type. [11 section 12.3.2] 1013 Symbol 'Name' not a member of class 'Name' -- The second operand of a scope operator or a '.' or '->' operator is not a member of the class (struct or union) expressed or implied by the left hand operand. [11 section 3.2] 1014 Explicit storage class not needed for member function 'Symbol' -- An explicit Symbol storage class such as extern or static was given in a separate definition of a class member. The storage class is effectively defined by its appearance within the class and may not be restated at definition time. 1015 Symbol 'Name' not found in class -- In an expression of the form X::Y, Y must be a member of X or of a public or protected base class of X. [11 section 10.4] 1016 Symbol 'Symbol' is supposed to denote a class -- In a base-specifier an identifier is supposed to specify a base class. However, the identifier was not previously declared in this module. [11 section 10] 1017 conflicting access-specifier 'String' -- Two different access specifiers were given in a simple base-specifier. [11 section 10] 1018 Expected a type after 'new' -- In an expression involving new, a type is expected after possibly processing a placement. None was found. [11 section 5.3.3] 1019 Could not find match for function 'Symbol(String)' -- In attempting to find a match between a set of overloaded functions or operators (name given as Symbol) and an actual argument list (provided as String) no match could be found. [11 section 13.2] 1022 Function: 'String' must be a class member -- There are four operators not to be defined except as class members. These are: = () [] -> The parameter String indicates which it is. [11 sections 13.4.3 and 13.4.6] 1023 Call 'String(String)' is ambiguous; candidates: 'String' -- A call to an overloaded function or operator is ambiguous. The candidates of choice are provided in the message. [11 section 13.2] 1024 No function has same argument count as 'Name' -- A call to an overloaded function could not be resolved successfully because no function is declared with the same number of arguments as in the call. [11 section 13.2] 1025 No function matches invocation 'Name' on arg no. Integer -- A call to an overloaded function could not be resolved because each declared function has a type incompatibility with the indicated argument. [11 section 13.2] 1026 Undominated function 'String' does not dominate 'String' on call to 'String' -- A call to an overloaded function could not be resolved because no one function dominates all others. This is a subtle issue in the overload resolution process. The selected function must be strictly better than any non-selected function in at least one argument. [11 section 13.2] 1027 Non-consecutive default arguments in function 'String', assumed 0 -- Default arguments need to be consecutive. For example void f(int i=0, int j, int k=0); is illegal. [11 section 8.2.6] 1028 Last argument not default in first instance of function 'String', assumed 0 -- If any argument of a function is given a default value then all subsequent arguments need to be given a default value. [11 section 8.2.6] 1029 Default argument repeated in function 'String' -- A default value for a given argument for a given function should only be given once. [11 section 8.2.6] 1030 Not all arguments after arg no. Integer are default in function 'String' -- An argument that has a default value must either be followed by another argument that has a default value, or must be the last argument. [11 section 8.2.6] 1031 Local variable 'Symbol' used in default argument expression -- Default values for arguments may not use local variables. [11 section 8.2.6] 1032 Member 'String' cannot be called without object -- There was an attempt to call a non-static member function without specifying or implying an object that could serve as the basis for the this pointer. If the member name is known at compile time it will be printed with the message. [11 section 5.24] 1033 Static member functions cannot be virtual -- You may not declare a static member function virtual. [11 section 10.2] 1034 Static member 'Symbol' is global and cannot be redefined -- This can come as a surprise to the novice C++ programmer. The word 'static' within a class definition is used to describe a member that is alone and apart from any one object of a class. But such a member has program scope not file scope. The word 'static' outside a class definition implies file scope not program scope. [11 section 9.4] 1035 Non-static member 'Symbol' cannot initialize a default argument -- A default argument cannot be initialized from a class member unless an instantiation of the class is provided. [11 section 8.2.6] 1036 ambiguous reference to constructor; candidates: 'String' -- There is more than one constructor that can be used to make a desired conversion. [11 section 12.3.2] 1037 ambiguous reference to conversion function; candidates: 'String' -- There is more than one conversion function (of the form operator type () ) that will perform a desired conversion. [11 section 12.3.2] 1038 type 'Name' not found, nested type 'Name::String' assumed -- We have found what appears to be a reference to a type but no such type is in scope. We have, however, been able to locate a type buried within another class. Is this what the user intended? If this is what is intended, use full scoping. If your compiler doesn't support the scoping, suppress with -esym. [11 section 3.2] 1039 Symbol 'Symbol' is not a member of class 'String' -- In a declaration for the symbol X::Y, Y was not previously established as a member of X. [11 section 10.4] 1040 Symbol 'Symbol' is not a legal declaration within class 'String' -- A declaration of the symbol X::Y appears within a class definition (other than for class X). It is not a friend declaration. Therefore it is in error. 1041 Can't declare 'String', assumed 'operator String' -- This message can be given with String equal to new or delete. Each 'String' in this message has the same value. A common mistake with beginning C++ programmers is to declare (and/or define) new when they mean to define opera tor new. We presume this was what was intended. [11 section 12.5] 1042 At least one class-like operand is required with Name -- In defining (or declaring) an operator you must have at least one class as an operand. [11 section 13.4] 1043 Attempting to 'delete' a non-pointer -- An expression being delete'd is a non-pointer, non-array. You may only delete that created with an invocation of new. [11 section 5.3.4] 1046 member 'Symbol', referenced in a static function, requires an object -- The Symbol is a non-static member of a class and hence requires a class instantiation. None is in sight. [10 section 9.4] 1047 a template declaration must be made at file scope -- A template declaration may not appear within a function or within a class. [10 section 14.1] 1048 expected a constant expression -- Within a template argument list a constant expression was expected. An expression of the form T was encountered and arg i for some i corresponds to a non-class parameter in the original template declaration. Such arguments need to be constants. [10 section 14.5] 1049 Too many template arguments -- There are more arguments in the template class-name than there were parameters in the original template declaration. [10 section 14.5] 1050 expected a template argument list '<...>' for template 'Symbol' -- The name of a class template identified by Symbol was used without specifying a template argument list. [10 section 14.5] 1051 Symbol 'Name' is both a function and a variable -- Whereas it is possible to overload a function name by giving it two different parameter lists, it is not possible to overload a name in any other way. In particular a function name may not also be used as a variable name. [11 section 9.2] 1052 a type was expected, 'class' assumed -- A template parameter list consists of 2 kinds of parameters: class identifier and type. The parameter did not begin with class and was not a type. [10 section 14.5] 1053 'String' cannot be distinguished from 'String' -- An overloaded function name had two parameter lists that were so close that discrimination between them would be difficult and error prone. Eg. void f(const int); and void f(int); [11 section 13] 1054 template variable declaration expects a type, int assumed -- An expression of the form T was encountered. One of the arguments corresponding to a type parameter in the original template declaration is not a type. [10 section 14.5] 1055 Symbol 'Symbol' undeclared, assumed to return int -- Whereas in C you may call a function without a prior declaration, in C++ you must supply such a declaration. For C programs you would have received an Informational message ( 718) in this event. [11 section 5.2.2] 1056 assignment from void * is not allowed in C++ -- Whereas in C you may assign from void* to any other (data) pointer without a diagnostic, in C++ you may not do this. It will require a cast. [11 section 4.6] 1057 member 'Symbol' cannot be used without an object -- The indicated member referenced via scope operator cannot be used in the absence of this pointer. [11 section 5.2.4] 1058 Initializing a non-const reference 'Symbol' with a non-lvalue -- A reference is normally initialized with an lvalue. If you attempt to initialize a reference with a non-lvalue, a temporary is created to serve as a surrogate lvalue. However, modifications made to the temporary will be lost. This was legal at one time and is now illegal. Make the reference a const if you can. You may be initializing a reference without realizing it. A member function has an implicit parameter, which is taken to be a reference to its object. If this is the situation make the member const. That is, use void f(...) const; rather than void f(...); 1059 Can't convert from Type to Type -- An attempt was made to initialize a reference with an object having a type other than the target type but no function could be found to effect the required conversion. [11 section 12.3] 1060 String member 'Symbol is not accessible to non-member non-friend functions -- There is an attempt to access a private or protected member of a class and the access is considered a violation of the access rules (although everything else proceeds as though no violation occurred). Specifically, the function attempting to make access must be a friend or member of the nominal class through which the access is made. See also 1061. [11 section 11] 1061 String member 'Symbol' is not accessible through non-public inheritance -- There is an attempt to access a private, protected or public member (the text of the message indicates which kind as well as which member) of a class through a class derived from the original. There is an access violation (see 1060 for the more common access violation) critically dependent on the fact that the inheritance relationship is non-public. [11 section 11.2] 1062 template must be either a class or a function -- Following template < arglist > the parser expects to find either the token class or a function declaration or definition. [10 section 14.5] 1063 Argument to copy constructor for class 'Symbol' should be a reference -- A constructor for a class closely resembles a copy constructor. A copy constructor for class X is typically declared as: X( const X &) If you leave off the '&' then a copy constructor would be needed just to copy the argument into the copy constructor. This is a runaway recursion. [11 section 12.1] 1064 Template parameter list for template 'Symbol' inconsistent with Location -- The template parameter list for a template function declaration or definition is inconsistent with that of a prior declaration or definition. [10 section 14.5] 1065 Symbol 'Symbol' not declared as "C" conflicts with Location -- A symbol previously declared as extern "C" in some other module is not declared as extern "C" in this module. This could be the source of very mysterious linker diagnostics since a name declared as extern "C" is not subject to the name mangling procedures that strictly C++ functions are. [11 section 7.4] 1066 Symbol 'Symbol' declared as "C" conflicts with Location -- A symbol is being declared as extern "C" and was not so declared in some other module. This could be the source of very mysterious linker diagnostics since a name declared as extern "C" is not subject to the name mangling procedures that strictly C++ functions are. [11 section 7.4] 1067 invalid prototype for function 'Symbol' -- Whenever operator delete or operator delete [] is defined its first parameter must be declared as void *. For member functions an optional second parameter may be size_t. [10 section 12.5]. 1068 Symbol 'Symbol' can not be overloaded -- operator delete or operator delete [] can be redefined but not overloaded. There can only be one operator delete and one operator delete [] but neither of these can be overloaded. [10 section 12.5]. 1069 Symbol 'Name' is not a base class of class 'Name' -- Within a constructor initialization list a name was found that did not correspond to either a direct base class of the class being defined or a member of the class. 1070 No scope in which to find symbol 'Name' -- This could arise in an expression of the form X::Y where X does not represent a valid scope. 1071 Constructors and destructors can not have return type -- Constructors and destructors may not be declared with a return type, not even void. See ARM Section 12.1 and 12.4. 1072 Reference variable 'Symbol' must be initialized -- A reference variable must have an initializer at the point of declaration. 1073 Insufficient number of template parameters; 'String' assumed -- A (class) template instantiation did not have a sufficient number of parameters. String indicates what the missing argument is presumed to be. 1074 Expected a namespace identifier -- In a declaration of the form: namespace name = scoped-identifier the scoped-identifier must identify a namespace. 1075 Ambiguous reference to symbol 'Symbol' and symbol 'Symbol' -- Two namespaces contain the same name. A reference to such a name could not be disambiguated. You must fully qualify this name in order to indicate the name intended. 1077 Could not evaluate default template parameter 'String' -- The evaluation of template parameters is deferred until needed. Thus: template< class T = abc > class A { /* ... */ }; will be greeted with an Error 1077 only if an instantiation of A requires evaluation of the default argument and if that evaluation cannot be made. In that event int is assumed for type parameters and 0 is assumed for object parameters. 1078 class 'Symbol' should not have itself as a base class -- The following situation will trigger this message. class A : public A { }; You can't define A in terms of itself as there is no escape from the recursive plummet. 1079 Could not find '>' or ',' to terminate template parameter at Location -- The default value for a template parameter appears to be malformed. For example, suppose the user mistakenly substituted a ']' for a '>' producing the following: template class X { }; This will cause PC-lint/FlexeLint to process to the end of the file looking (in vain) for the terminating pointy bracket. Not finding it will cause this message to be printed. Fortunately, the message will bear the Location of the malformed template. 1080 Definition for class 'Name' is not in scope -- This message would be issued whenever a class definition were required and it were not available. For example: Class X; // declare class X X *p; // OK, no definition required X a; // Error 1080 17.8 C++ Warning Messages 1401 member symbol 'Symbol' (Location) not initialized by constructor -- The indicated member symbol was not initialized by a constructor. Was this an oversight? 1402 member 'Symbol' (Location) not initialized -- The indicated member symbol was not initialized before use. Either this is in a constructor where it is presumed that no members are pre-initialized or this is after a statement removing its initialization such as a delete or a free. 1403 member 'Symbol' (Location) not initialized -- The indicated member symbol was not initialized before a point where its address is being passed to a constant pointer. This looks suspicious. Either this is in a constructor where it is presumed that no members are pre-initialized or this is after a statement removing its initialization such as a delete or a free. 1404 deleting an object of type 'Symbol' before type is defined -- The following situation was detected: class X; ... X *p; ... delete p; That is, a placeholder declaration for a class is given and an object of that type is deleted before any definition is seen. This may or may not be followed by the actual class definition: class X { ... }; A delete before the class is defined is dangerous because, among other things, any operator delete that may be defined within the class could be ignored. 1411 Member with different signature hides virtual member 'Symbol' (Location) -- A member function has the same name as a virtual member of a derived class but it has a different signature (different parameter list). This is legal but suspicious, because it looks as though the function would override the virtual function but doesn't. You should either adjust the parameters of the member so that the signatures conform or choose a different name. See also message 1511. 1412 Reference member 'Symbol' is not initialized -- A class member typed reference to class (or struct or union) is mentioned in a constructor initializer list. But the class (or struct or union) referenced has no constructor and so is never initialized. 1413 function 'Symbol' is returning a temporary via a reference -- It appears that a function (identified as Symbol in the message) declared to return a reference is returning a temporary. According to the C++ standard (Section 12.2), in addressing the issue of binding temporary values to references, says "A temporary bound to the returned value in a function return statement ... persists until the function exits". Thus the information being returned is not guaranteed to last longer than the function being called. It would probably be better to return by value rather than reference. Alternatively, you may return a static variable by reference. This will have validity at least until the next call upon the same function. 1501 data member 'Symbol' has zero size -- A data member had zero size. It could be an array of zero length or a class with no data members. This is considered an error in C (Error 43) but in C++ we give this warning. Check your code to make sure this is not an error. Some libraries employ clever templating, which will elicit this message. In such a case it is necessary for you to inhibit the message outright (using -e1501) or through a judicious use of -esym(1501,...). 1502 defined object 'Symbol' has no data members -- A variable (Symbol) is being instantiated that belongs to a class that contains no data members (either directly or indirectly through inheritance). [11 section 9] 1503 a tagged union is not anonymous -- A tagged union without a declarator appeared within a struct/union declaration. An anonymous union requires no tag. [11 section 9.5] 1504 useless struct declaration -- An untagged struct declaration appeared within a struct/union and has no declarator. It is not treated like an anonymous union. Was this intended? 1505 no access specifier provided, 'String' assumed -- A base class specifier provides no access specifier (public, private or protected). An explicit access specifier is always recommended since the default behavior is often not what is expected. For example: class A : B { int a; }; would make B a private base class by default. class A : private B { int a; }; is preferred if that's what you want. [11 section 11.1] 1506 Call to virtual function 'Symbol' within a constructor or destructor -- A call to a virtual function was found in a constructor or a destructor of a class. If this class is a base class of some other class (why else make a virtual call?), then the function called is not the overriding function of the derived class but rather the function associated with the base class. If you use an explicit scope operator this message will not be produced. [20 section 9] 1507 attempting to 'delete' an array -- The type of an object to be delete'd is usually a pointer. This is because operator new always returns a pointer and delete may only delete that allocated via new. Perhaps this is a programmer error attempting to delete an auto array? [19] 1509 base class destructor for class 'Name' is not virtual -- The indicated class is a base class for some derived class. It has a non-virtual destructor. Was this a mistake? It is conventional to virtualize destructors of base classes so that it is safe to delete a base class pointer. [19] 1510 base class 'Name' has no destructor -- The indicated class is a base class for some derived class that has a destructor. The base class does not have a destructor. Is this a mistake? The difficulty that you may encounter is this; if you represent (and manipulate) a heterogeneous collection of possibly derived objects via a pointer to the base class then you will need a virtual base class destructor to invoke the derived class destructor. [13 section 4] 1511 Member hides non-virtual member 'Symbol' (Location) -- The named member of a derived class hides a similarly named member of a base class. Moreover, the base class member is not virtual. Is this a mistake? Was the base member supposed to have been declared virtual? By unnecessarily using the same name, confusion could be created. 1512 destructor for base class 'Symbol' (Location) is not virtual -- In a final pass through all the classes, we have found a class (named in the message) that is the base class of a derivation and has a destructor but the destructor is not virtual. It is conventional for inherited classes to have virtual destructors so that it is safe to 'delete' a pointer to a base class. [19] 1513 storage class ignored -- A storage class (one of auto, extern, or register) was found within a class definition. The only storage classes that are significant when declaring members are static and typedef. [11 section 9.2] 1514 Creating temporary to copy 'Type' to 'Type' (context: Context) -- A temporary was created in order to initialize (or pass a value to or return a value to) a reference. This is suspect because any modification to the value will be a modification of this temporary. This message is not issued when initializing a const reference. [11 section 12.2] 1515 Default constructor not available for member 'Symbol' -- A member of a class was found that had a type for which a constructor was defined but for which a default constructor (one with no arguments) was not defined. 1516 Data member hides inherited member 'Symbol' (Location) -- A data member of a class happens to have the same name as a member of a base class. Was this deliberate? Identical names can cause confusion. To inhibit this message for a particular symbol or for an identifiable set of symbols use -esym(). 1520 Multiple assignment operators for class 'Symbol' -- More than one assignment operator has been declared for a given class. For example, for class X there may have been declared: void operator=(X); void operator=(X) const; Which is to be used for assignment? 1521 Multiple copy constructors for class 'Symbol' -- For a given class, more than one function was declared that could serve as a copy constructor. Typically this means that you declared both X( X& ) and X( const X& ) for the same class. This is probably a mistake. 1522 Symbol 'Symbol' is an array of empty objects -- An array (Symbol) is being allocated. Each member of the array appears to be empty. Although this is legal, it could be the result of human error. If this is deliberate policy, inhibit the message, either globally, or for this Symbol. 1524 new in constructor for class 'Name' which has no explicit destructor -- A call to new has been found in a constructor for a class for which no explicit destructor has been declared. A destructor was expected because how else can the storage be freed? [10 section 12.5] 1526 Member function 'Symbol' (Location) not defined -- A member function (named in the message) of a non-library class was not defined. This message is suppressed for unit checkout (-u option). 1527 static member 'Symbol' (Location) not defined -- A static data member (named in the message) of a non-library class was not defined. In addition to its declaration within the class, it must be defined in some module. 1528 call to String does not match function template String -- The first String of the message designates an actual function call that appeared to be the invocation of the template function identified by the second String. No match could be made between the arguments of the call and the template parameters. 1529 Symbol 'Symbol' not first checking for assignment to this -- The assignment operator does not appear to be checking for assignment of the value of a variable to itself (assignment to this). Specifically PC-lint/FlexeLint is looking for one of: if( &arg == this ) if( &arg != this ) if( this == &arg ) if( this != &arg ) as the first statement of the function. It is important to check for a self assignment so as to know whether the old value should be subject to a delete operation. This is often overlooked by a class designer since it is counter-intuitive to assign to oneself. But through the magic of aliasing (pointers, references, function arguments) it is possible for an unsuspecting programmer to stumble into a disguised self-assignment [12, Item 17]. If you are currently using the following test if( arg == *this) we recommend you replace this with the more efficient: if( &arg == this || arg == *this) 1531 Symbol 'Symbol' (Location) should have compared argument against sizeof(class) -- This warning is given for either operator new or operator delete when defined as member functions of a class that is the base class of a derivation. In this case you can't be certain of the size of allocation and therefore your allocation functions should test the size parameter for equality to the sizeof the class. See Elective Note 1921 for more details. 1532 Symbol 'Symbol' not checking argument for NULL -- This message is given for a function operator delete which is a member function of a class that does not have a destructor. It should check for NULL because delete p where p has the NULL value will be passed in to it. See also 1922. 1533 Repeated friend declaration for symbol 'Symbol' -- A friend declaration for a particular symbol (class or function) was repeated in the same class. Usually this is a harmless redundancy. 1534 static variable 'Symbol' found within inline function in header -- A static variable (Symbol) was found within an inline function within a header file. This can be a source of error since the static variable will not retain the same value across multiple modules. Rather each module will retain its own version of the variable. If multiple modules need to use the function then have the function refer to an external variable rather than a static variable. Conversely if only one module needs to use the function then place the definition of the function within the module that requires it. [23, Item 26]. 1535 Exposing low access data through member 'Symbol' -- A member function is returning an address being held by the indicated member symbol (presumably a pointer). The member's access (such as private or protected) is lower than the access of the function returning the address. 1536 Exposing low access member 'Symbol' -- A member function is returning the non-const address of a member either directly or via a reference. Moreover, the member's access (such as private or protected) is lower than the access of the function returning the address. For example: class X { private: int a; public: int *f() { return &a; } }; This looks like a breach of the access system [12, Item 30]. You may lower the access rights of the function, raise the accessibility of the member or make the return value a const pointer or reference. In the above example you could change the function to: const int *f() { return &a; } 1537 const function returns pointer data member 'Symbol' -- A const function is behaving suspiciously. It is returning a pointer data member (or equivalently a pointer to data that is pointed to by a data member). For example, class X { int *p; int *f() const { return p; } }; Since f is supposedly const and since p is presumptively pointing to data that is logically part of class X we certainly have the potential for a security breach. Either return a pointer to const or remove the const modifier to the function. [12, Item 29 ]. Note, if a const function returns the address of a data member then a 605 (capability increase) is issued. 1538 base class 'Name' absent from initializer list for copy constructor -- The indicated base class did not appear in the initializer list for a copy constructor. Was this an oversight? If the initializer list does not contain an initializer for a base class, the default constructor is used for the base class. This is not normally appropriate for a copy constructor. The following is more typical: class B { ... }; class D : public B { D( const D &arg ) : B( arg ) { ... } ... }; 1539 member 'Symbol' (Location) not assigned by assignment operator -- The indicated Symbol was not assigned by an assignment operator. Was this an oversight? It is not strictly necessary to initialize all members in an assignment operator because the 'this' class is presumably already initialized. But it is easy to overlook the assignment of individual members. It is also easy to overlook your responsibility to assign base class members. This is not done for you automatically. [12, Item 16] The message is not given for const members or reference members. If you have a member that is deliberately not initialized you may suppress the message for that member only using -esym. 1540 pointer member 'Symbol' (Location) neither freed nor zero'ed by destructor -- The indicated member is a non-static pointer member of a class that was apparently not freed by the class' destructor. Was this an oversight? By freeing, we mean either a call to the free() function or use of the delete operator. If the pointer is only intended to point to static information during its lifetime then, of course, it never should be freed. In that case you should signal closure by assign ing it the NULL pointer (0). 1541 member 'Symbol' (Location) possibly not initialized by constructor -- The indicated member symbol may not have been initialized by a constructor. Was this an oversight? Some of the paths that the constructor takes do initialize the member. See Section 9. 1542 member 'Symbol' (Location) possibly not initialized -- The indicated member symbol may not have been initialized before use. Either this is in a constructor where it is presumed that no members are pre-initialized or this is after a statement removing its initialization such as a delete or a free. See Section 9. 1543 member 'Symbol' (Location) possibly not initialized -- The indicated member symbol may not have been initialized before a point where its address is being passed to a constant pointer. This looks suspicious. Either this is in a constructor where it is presumed that no members are pre-initialized or this is after a statement removing its initialization such as a delete or a free. 1544 value of variable 'Symbol' (Location) indeterminate (order of initialization) -- A variable (identified by Symbol) was used in the run-time initialization of a static variable. However this variable itself was initialized at run-time. Since the order of initialization cannot be predicted this is the source of possible error. Whereas addresses are completely known at initialization time values may not be. Whether the value or merely the address of a variable is used in the initialization of a second variable is not an easy thing to determine when an argument is passed by reference or via pointer. For example, class X { X( const X & ); }; extern X x1; X x2 = x1; X x1 = x2; It is theoretically possible, but unlikely, that the constructor X() is interested only in the address of its argument and not its current value. If so, it only means you will be getting a spurious report, which you can suppress based on variable name. However, if the const is missing when passing a reference parameter (or a pointer parameter) then we cannot easily assume that values are being used. In this case no report will be issued. The moral is that if you want to get the checking implied by this message you should make your constructor reference arguments const. 1545 value of variable 'Symbol' used previously to initialize variable 'Symbol' (Location) -- A variable identified by Symbol was used previously to initialize some other variable. This variable is now itself being initialized with run-time code. The order of these initializations cannot be predicted. See also message 1544. 1546 throw() called within destructor 'Symbol' -- The body of a destructor (signature provided within the message) contains a throw not within a try block. This is dangerous because destructors are themselves triggered by exceptions in sometimes unpredictable ways. The result can be a perpetual loop. [23, Item 11] 1547 Assignment of array to pointer to base class (Context) -- An assignment from an array of a derived class to a pointer to a base class was detected. For example: class B { }; class D : public B {}; D a[10]; B *p = a; // Warning 1547 B *q = &a[0]; // OK In this example p is being assigned the address of the first element of an array. This is fraught with danger since access to any element other than the zeroeth must be considered an error (we presume that B and D actually have or have the potential to have different sizes). [23, Item 3]. We do not warn about the assignment to q because it appears that the programmer realizes the situation and wishes to confine q to the base object of the zeroeth element of a only. As a further precaution against inappropriate array access, out of bounds warnings are issued for subsequent references to p[1] and q[1]. 1548 Exception specification for 'Symbol' conflicts with Location -- The exception specification of a function begins with the keyword 'throw' and follows the prototype. Two declarations were found for the same function with inconsistent exception specifications. 1549 Exception thrown for function 'Symbol' not declared to throw -- An exception was thrown (i.e., a throw was detected) within a function and not within a try block; moreover the function was not declared to throw anything. The preferred remedy is to declare the function as potentially throwing an exception. [23, Item 11] 1550 function 'Symbol' may throw an exception in function 'Symbol' -- A function was called (first Symbol) which was declared to throw an exception. The call was not made from within a try block and the function making the call was not declared to throw anything. Either declare the calling function as potentially throwing an exception, or place the call inside a try block and catch the throw. 1551 function 'Symbol' may throw an exception in destructor 'Symbol' -- A call to a function (name given by the first Symbol) was made from within a destructor. The function was declared as potentially throwing an exception. Such exceptions need to be caught within a try block because destructors should never throw exceptions. [23, Item 11]. 1552 Converting pointer to array-of-derived to pointer to base -- This warning is similar to Warning 1547 and is sometimes given in conjunction with it. It uses value tracking to determine that an array (that could be dynamically allocated) is being assigned to a base class pointer. For example, Derived *d = new Derived[10]; Base *b; b = d; // Warning 1552 b = &d[0]; // OK [23, Item 3] Also, see the article by Mark Nelson (Bug++ of the Month, Windows developer's Journal, May 1997, pp. 43-44). 1553 struct 'Symbol' declared as extern "C" contains C++ substructure 'Symbol' (Location) -- A C++ substructure was found in a structure or class declared as extern "C". Was this intended? 1554 Direct pointer copy of member 'Symbol' within copy constructor: 'Symbol' -- In a copy constructor a pointer was merely copied rather than recreated with new storage. This can create a situation where two objects have the same data and this, in turn, causes problems when these objects are deleted or modified. For example, the following class will draw this warning: class X { char *p; X( const X & x ) { p = x.p; } ... }; Here, member p is expected to be recreated using new or some variant. 1555 Direct pointer copy of member 'Symbol' within copy assignment operator: 'Symbol' -- In a copy assignment operator a pointer was merely copied rather than recreated with new storage. This can create a situation where two objects have the same data and this, in turn, causes problems when these objects are deleted or modified. For example, the following class will draw this warning: class X { char *p; X& operator=( const X & x ) { p = x.p; } ... }; Here, member p is expected to be recreated using new or some variant. 1556 'new Type(integer)' is suspicious -- A new expression had the form new T(Integer) where type T has no constructor. For example: new int(10); will draw this warning. The expression allocates an area of storage large enough to hold one integer. It then initializes that integer to the value 10. Could this have been a botched attempt to allocate an array of 10 integers? Even if it was a deliberate attempt to allocate and initialize a single integer, a casual inspection of the code could easily lead a reader astray. The warning is only given when the type T has no constructor. If T has a constructor then either a syntactic error will result because no constructor matches the argument or a match will be found. In the latter case no warning will or should be issued. 1557 const member 'Symbol' is not initialized -- A class member typed const class (or struct or union) is mentioned in a constructor initializer list. But the class (or struct or union) referenced has no constructor and hence the member is not initialized. See also message 1769. 1559 Uncaught exception 'Name' may be thrown in destructor 'Symbol' -- The named exception occurred within a try block and was either not caught by any handler or was caught but then thrown from the handler. Destructors should normally not throw exceptions [23, Item 11]. 1560 Uncaught exception 'Name' not on throw-list of function 'Symbol' -- A direct or indirect throw of the named exception occurred within a try block and was either not caught by any handler or was rethrown by the handler. Uncaught exceptions should normally be declared in the function's exception specification. 1561 Reference initialization causes loss of const/volatile integrity (Context) -- A reference initialization is resulting in a capability gain that can cause a loss of const or volatile integrity. Typically the message is given on initializing a non-const reference with a const. For example: void f( int &x ); const int n = 0; ... f(n); Here, function f() could assign a value to its argument and thereby modify n, which is declared to be const. The message can also be issued when a pointer is initialized. Consider the following example. void h( const int *&q ); int *p; ... h(p); It might seem that passing a regular (i.e., non-const) pointer to a const int * could cause no harm. That would be correct if it were not for the reference. If function h() were to assign a pointer to const to its parameter q then upon return from the call, p could be used to modify const data. There are many subtle cases that can boggle the mind. See the commentary to Message 605. 17.9 C++ Informational Messages 1701 redundant access-specifier 'String' -- The given access specifier (one of 'public', 'private' or 'protected') has been repeated. [11 section 11.1] 1702 operator 'Name' is both an ordinary function 'String' and a member function 'String' -- In attempting to resolve the definition of an operator it was found that the same operator was declared as both a member function and a non-member function. Was this intended? Symmetric binary operators (such as '+', '-', '==', '>', etc.) are usually defined external to a class definition so that they can support non-objects on the left hand side. [11 section 13.4.2] 1703 Function 'String' arbitrarily selected. Refer to Error 'Integer' -- This informational message is given with error numbers 1023, 1024, 1025 and 1026. These are issued when an error is encountered during the overload resolution process, and is issued merely to indicate which function was arbitrarily selected. [11 section 13.2] 1704 Constructor 'Symbol' has private access specification -- A private constructor is legal and has its uses but can also result in messages that are difficult to interpret. If you use private constructors as a programming technique then you may suppress this message with a -e1704. But it's probably better to suppress this on a constructor by constructor basis using -esym. 1705 static class member may be accessed by the scoping operator -- A static class member was accessed using a class object and -> or . notation. For example: s.member or p->member But an instance of the object is not necessary. It could just as easily have been referenced as: X::member where X is the class name. [10 section 9.4] 1706 Declaration with scope operator is unusual within a class -- Class members within a class are not normally declared with the scope operator. For example: class X { int X::n; ... will elicit this message. If the (redundant) class specification (X::) were replaced by some different class specification and the declaration was not friend an error ( 1040) would be issued. [11 section 9.2] 1707 static assumed for String -- operator new() and operator delete(), when declared as member functions, should be declared as static. They do not operate on an object instantiation (implied this pointer). [11 section 12.5] 1708 typedef 'Symbol not declared as "C" conflicts with Location -- A typedef symbol previously declared as extern "C" was not so declared at the current location. This is not considered as serious a situation as is indicated by message 1065, which is given for external function and variable names. If this is your programming style you may suppress this message. 1709 typedef 'Symbol' declared as "C" conflicts with Location -- A typedef symbol was previously not declared as extern "C" but is so declared at the current location. This is not considered as serious a situation as is indicated by message 1066, which is given for external function and variable names. If this is your programming style you may suppress this message. 1711 class 'Symbol' (Location) has a virtual function but is not inherited -- The given class has a virtual function but is not the base class of any derivation. Was this a mistake? There is no advantage to making member functions virtual unless their class is the base of a derivation tree. In fact, there is a disadvantage because there is a time and space penalty for virtual functions. This message is not given for library classes and is suppressed for unit checkout. [13 section 4] 1712 default constructor not defined for class 'Name' -- A class was defined with one or more constructors but none of these could be used as a (0 argument) default constructor. Is this an omission? The default constructor is used in declarations and for new when no explicit initialization is given. It is also used when the class is a base class and no mem-initializer is given. It is used for arrays as well. A default constructor should therefore be omitted only for good reason. If you have such a good reason for class X you can employ option -esym(1712,X). [19] 1713 Redundant parentheses ignored -- A vacuous initializer within a new-initializer for an object for which a constructor was not defined is a "syntactic convenience and has no special meaning". For example, new double is the same as new double(). [11 section 5.3.3] 1714 Member function 'Symbol' (Location) not referenced -- A member function was not referenced. This message is automatically suppressed for unit checkout (-u) and for members of a library class. 1715 static member 'Symbol' (Location) not referenced -- A static data member of a class was not referenced. This message is automatically suppressed for unit checkout (-u) and for members of a library class. 1716 Virtual member function 'Symbol' (Location) not referenced -- A virtual member function was apparently not referenced. Not only was the function itself not referenced but the function or functions that it overrides were not referenced either. The message is not given if the member function itself or any member function that it overrides is a library member function. This is because the original virtual function may be called implicitly by the library. This message is suppressed for unit checkout (-u). 1717 empty prototype for function declaration, assumed '(void)' -- An empty prototype, as in: void f(); has a different meaning in C than in C++. In C it says nothing about the arguments of the function; in C++, it says there are no arguments. This message is not given for member function declarations or for function definitions. Rather, weaker Elective Notes ( 1917 and 1918) are given. This is because the chance of ambiguity does not exist in these cases. [11 section 8.2.5] 1718 expression within brackets ignored -- In the expression: delete [ expression ] p the expression is ignored. The expression is a vestige of an earlier time when this information provided a count of the number of items in the array being released. Note that empty square brackets are considered necessary for deleting an array. This is a complaint directed toward the expression within the brackets not the brackets themselves. [11 section 5.3.4] 1719 assignment operator for class 'Symbol' has non-reference parameter -- The typical assignment operator for a class is of the form: X& operator =(const X &) If the argument is not a reference then your program is subject to implicit function calls and less efficient operation. [11 section 13.4.3] 1720 assignment operator for class 'Symbol' has non-const parameter -- The typical assignment operator for a class is of the form: X& operator =(const X &) If the argument is not const then your program will not be diagnosed as completely as it might otherwise be. [11 section 13.4.3] 1721 operator =() for class 'Symbol' is not assignment operator -- The assignment operator for a class has the form: X& operator =(const X &) A member function whose name is operator =, but does not have that form, is not an assignment operator. This could be a source of subtle confusion for a program reader. If this is not an error you may selectively suppress this message for the given class. [11 section 13.4.3] 1722 assignment operator for class 'Symbol' does not return a reference to class -- The typical assignment operator for a class X is of the form: X& operator =(const X &); The reason for returning a reference to class is to support multiple assignment as in: a = b = c [11 section 13.4.3] 1724 Argument to copy constructor for class 'Symbol' should be a const reference -- A copy constructor for class X is typically declared as: X( const X & ); If you leave off the 'const' then some diagnostics will not be possible. [19] 1725 class member 'Symbol' is a reference -- There are a number of subtle difficulties with reference data members. If a class containing a reference is assigned, the default assignment operator will presumably copy the raw underlying pointer. This violates the principle that a reference's underlying pointer, once established, is never modified. Some compilers protect against this eventuality by refusing to create a default assignment operator for classes containing references. Similar remarks can be made about copy constructors. If you are careful about how you design your copy constructors and assignment operators, then references within classes can be a useful programming technique. They should not, however, be employed casually. [21 section 2.1.3] 1726 taking address of overloaded function name 'Symbol' -- A reference is being made to an overloaded function without an immediately following '('. Thus there is no argument list to distinguish the function intended. Resolution of the overloaded name can only be made by analyzing the destination. Is this what the programmer intended? [11 section 13.3] 1727 inline 'Symbol' not previously defined inline at (Location) -- A function declared or defined inline was not previously declared inline. Was this intended? If this is your standard practice then suppress this message. [11 section 9.3.2] 1728 Symbol 'Symbol' was previously defined inline at (Location) -- A function was previously declared or defined inline. The inline modifier is absent from the current declaration or definition. Was this intended? If this is your standard practice then suppress this message. [11 section 9.3.2] 1729 Initializer inversion detected for member 'Symbol' -- In a constructor initializer the order of evaluation is determined by the member order not the order in which the initializers are given. At least one of the initializers was given out of order. Was there a reason for this? Did the programmer think that by changing the order that he/she would affect the order of evaluation? Place the initializers in the order of their occurrence within the class so that there can be no mistaken assumptions. [12, Item 13] 1730 class/struct inconsistency for symbol 'Symbol' (conflicts with Location) -- An object is declared both with the keyword class and with the keyword struct. Though this is legal it is suspect. [11 section 7.1.6] 1732 new in constructor for class 'Name' which has no assignment operator -- Within a constructor for the cited class, there appeared a new. However, no assignment operator was declared for this class. Presumably some class member (or members) points to dynamically allocated memory. Such memory is not treated properly by the default assignment operator. Normally a custom assignment operator would be needed. Thus, if x and y are both of type Symbol x = y; will result in pointer duplication. A later delete would create chaos. [12, Item 11] 1733 new in constructor for class 'Name' which has no copy constructor -- Within a constructor for the cited class, there appeared a new. However, no copy constructor was declared for this class. Presumably, because of the new, some class member (or members) points to dynamically allo cated memory. Such memory is not treated properly by the default copy constructor. Normally a custom copy constructor would be needed. [12, Item 11] 1734 Had difficulty compiling template function: 'Symbol' -- At template wrap-up time where there is an attempt to 'compile' each template function according to arguments provided, the cited function could not be processed fully. The difficulty may be the result of syntax errors cited earlier and if these errors are repaired then this message should go away. 1735 Virtual function 'Symbol' has default parameter -- A virtual function was detected with a default parameter. For example: class B { virtual void f( int n = 5 ); ... }; The difficulty is that every virtual function f overriding this virtual function must contain a default parameter and its default parameter must be identical to that shown above. If this is not done, no warnings are issued but behavior may have surprising effects. This is because when f() is called through a base class pointer (or reference) the function is determined from the actual type (the dynamic type) and the default argument is determined from the nominal type (the static type). [12, Item 38]. 1736 Redundant access specifier (String) -- An access specifier (one of public, private, or protected as shown in String) is redundant. That is, the explicitly given access specifier did not have to be given because an earlier access specifier of the same type is currently active. This message is NOT given for an access specifier that is the first item to appear in a class definition. Thus class abc { private: ... does not draw this message. The reason this message is issued is because it is very easy to make the following mistake. class A { public: // declare private members: ... public: // declare public members: ... In general there are no compiler warnings that would result from such an unintentional botch. 1737 Symbol 'Symbol' hides global operator new -- The indicated Symbol is a class member operator new. It is not compatible with the global operator new and, moreover, no other operator new within the class is argument list compatible with the global operator new. For this reason the user of these classes will get a surprise if he/she calls for new X where X is the class name. It will be greeted with an error. The solution is to define a single argument operator new as a class member. [12, Item 9]. 1738 non-copy constructor 'Symbol' used to initialize copy constructor -- In an initializer list for a copy constructor, a base class constructor was invoked. However, this base class constructor was not itself a copy constructor. We expect that copy constructors will invoke copy constructors. Was this an oversight or was there some good reason for choosing a different kind of con structor? If this was deliberate, suppress this message. See also message 1538. 1739 Binary operator 'Symbol' should be non-member function -- The indicated function was declared as a member function. There were a number of indicators to suggest that it should have been a non-member function. The class, X of which it was a member has a constructor that could be used to convert numeric values to X. The parameter to the operator was X or its equivalent. For this reason the operator would behave unsymmetrically. A numeric value on the right hand side would be promoted but not a value on the left hand side. For example, X op 27 would work but 27 op X would not. [12, Item 19]. 1740 pointer member 'Symbol' (Location) not directly freed or zero'ed by destructor -- A destructor did not free or zero a pointer member. However, it did call out to another (non-const) member function which may have done the required work. This Informational message is a companion to Warning 1540, which covers the situation where no member function is called from within the destructor. 1741 member 'Symbol' (Location) conceivably not initialized by constructor -- The indicated member symbol may not have been initialized by a constructor. Was this an oversight? There appears to be a path through a loop that does initialize the member and the warning is issued because it is not clear that the loop is always executed at least once. See Section 9. 1742 member 'Symbol' (Location) conceivably not initialized -- The indicated member symbol conceivably may not have been initialized by a constructor. Was this an oversight? Some of the execution paths that the constructor takes, do initialize the member. See Section 9. 1743 member 'Symbol' (Location) conceivably not initialized -- The indicated member symbol conceivably may not have been initialized before use. Either this is in a constructor where it is presumed that no members are pre-initialized or this is after a statement removing its initialization such as a delete or a free. See Section 9. 1744 member 'Symbol' (Location) possibly not initialized by private constructor -- The designated member was possibly not initialized by a private constructor. This message is similar to messages 1401, 1541 and 1741, which are given for ordinary (non private) constructors. It is given a special error number because a private constructor may be one that, by design, is never called and variables may be deliberately left uninitialized. In that case this message should be suppressed. 1745 member 'Symbol' (Location) not assigned by private assignment operator -- The indicated Symbol was not assigned by a private assignment operator. This is very much like Warning 1539 except that the assignment operator in question is private. A private assignment operator may simply be a device to thwart unintended use of the assignment operator. In this case you may not care about unassigned members. If this is so, suppress this message. The message is not given for const members or reference members. [12, Item 16] 1746 parameter 'Symbol' of function 'Symbol' could be made const reference -- The indicated parameter is a candidate to be declared as a const reference. For example: void f( X x ) { // x not modified. } Then the function definition can be replaced with: void f( const X &x ) { // x not modified. } The result is more efficient since less information needs to be placed onto the stack and a constructor need not be called. The message is only given with class-like arguments (including struct's and union's) and only if the parameter is not subsequently modified or potentially modified by the function. The parameter is potentially modified if it is passed to a function whose corresponding parameter is a reference (not const) or if its address is passed to a non-const pointer. [12, Item 22]. 1747 binary operator 'Symbol' returning a reference -- An operator-like function was found to be returning a reference. For example: X &operator+ ( X &, X & ); This is almost always a bad idea. [12, Item 23]. You normally can't return a reference unless you allocate the object, but then who is going to delete it. The usual way this is declared is: X operator+ ( X &, X & ); 1748 non-virtual base class 'Name' included twice in class 'Name' -- Through indirect means, a given class was included at least twice as a base class for another class. At least one of these is not virtual. Although legal, this may be an oversight. Such base classes are usually marked virtual resulting in one rather than two separate instances of the base class. This is done for two rea sons. First, it saves memory; second, references to members of such a base class will not be ambiguous. 1749 base class 'Symbol' of class 'Symbol' need not be virtual -- The designated base class is a direct base class of the second class and the derivation was specified as 'virtual'. But the base class was not doubly included (using this link) within any class in the entire project. Since a virtual link is less efficient than a normal link this may well be an unenlightened use of 'virtual'. [23, Item 24]. The message is inhibited if unit checkout (-u) is selected. 1750 local template 'Symbol' (Location) not referenced -- A 'local' template is one that is not defined in a header file. The template was not used in the module in which it was defined. 1752 catch parameter Integer is not a reference -- This message is issued for every catch parameter that is not a reference and is not numeric. The problem with pointers is a problem of ownership and delete responsibilities; the problem with a non-ref object is the problem of slicing away derivedness [23, Item 13]. 1753 Overloading special operator 'Symbol' -- This message is issued whenever an attempt is made to declare one of these operators as having some user-defined meaning: operator || operator && operator , The difficulty is that the working semantics of the overloaded operator is bound to be sufficiently different from the built-in operators, as to result in possible confusion on the part of the programmer. With the built-in versions of these operators, evaluation is strictly left-to-right. With the overloaded versions, this is not guaranteed. More critically, with the built-in versions of && and ||, evaluation of the 2nd argument is conditional upon the result of the first. This will never be true of the overloaded version. [23, Item 7]. 1754 Expected symbol 'Symbol' to be declared for class 'Symbol' -- The first Symbol is of the form: operator op= where op is a binary operator. A binary operator op was declared for type X where X is identified by the second Symbol. For example, the appearance of: X operator+( const X &, const X & ); somewhere in the program would suggest that a += version appear as a member function of class X. This is not only to fulfill reasonable expectations on the part of the programmer but also because operator+= is likely to be more efficient than operator+ and because operator+ can be written in terms of operator+=. [23, Item 22] The message is also given for member binary operators. In all cases the message is not given unless the return value matches the first argument (this is the implicit argument in the case of a member function). 1755 global template 'Symbol' (Location) not referenced -- A 'global' template is one defined in a header file. This message is given for templates defined in non-library header files. The template is not used in any of the modules comprising the program. The message is suppressed for unit checkout (-u). 1757 Discarded instance of post decrement/increment -- A postfix increment or postfix decrement operator was used in a context in which the result of the operation was discarded. For example: X a; ... a++; In such contexts it is just as correct to use prefix decrement/increment. For example this could be replaced with: X a; ... ++a; The prefix form is (or should be) more efficient than the postfix form because, in the case of user-defined types, it should return a reference rather than a value (see 1758 and 1759). This presumes that the side effects of the postfix form are equivalent to those of the prefix form. If this is not the case then either make them equivalent (the preferred choice) or turn this message off. [23, Item 6]. 1758 Prefix increment/decrement operator 'Symbol' returns a non-reference -- To conform with most programming expectations, a prefix increment/decrement operator should return a reference. Returning a reference is both more flexible and more efficient [23, Item 6]. The expected form is as shown below: class X { X & operator++(); // prefix operator X operator++( int ); // postfix operator ... }; 1759 Postfix increment/decrement operator 'Symbol' returns a reference. -- To conform with most programming expectations, a postfix increment/decrement operator should return a value as opposed to a reference. [23, Item 6]. See example in message 1758. 1760 Redundant template 'Symbol' defined identically at Location -- A template was defined identically in the same module. Was this a mistake? 1761 Declaration of function 'Symbol' hides overloaded function 'Symbol' (Location) -- A function declaration hides an overloaded function. This does not contribute to the overloaded-ness of the function but completely hides all the overloaded functions in some prior scope. If this is your intent suppress this message. 1762 Member function 'Symbol' could be made const -- The indicated (non-static) member function did not modify member data and did not call non-const functions. Moreover, it does not make any deep modification to the class member. A modification is considered deep if it modifies information indirectly through a class member pointer. Therefore it could and probably should be declared as a const member function. See also Info 1763 and Elective Note 1962. 1763 Member function 'Symbol' marked as const indirectly modifies class -- The designated symbol is a member function declared as const. Though technically valid, the const may be misleading because the member function modifies (or exposes) information indirectly referenced by the object. For example: class X { char *pc; char & get(int i) const { return pc[i]; } }; results in Info 1763 for function X::get. This is because the function exposes information indirectly held by the class X. Experts [24] recommend that a pair of functions be made available in this situation: class X { char *pc; const char & get(int i) const { return pc[i]; } char & get(int i) { return pc[i]; } }; In this way, if the object is const then only the const function will be called, which will return the protected reference. Related messages are also 1762 and 1962. See also [12, Item 29] for a further description. 1764 Reference parameter could be declared const reference -- As an example: int f( int & k ) { return k; } can be redeclared as: int f( const int & k ) { return k; } Declaring a parameter a reference to const offers advantages that a mere reference does not. In particular, you can pass constants, temporaries and const types into such a parameter where otherwise you may not. In addition it can offer better documentation. Other situations in which a const can be added to a declaration are covered in messages 818, 952, 953 and 954. 1768 Virtual function 'Symbol' has an access (String) different from the access (String) in the base class (String) -- An overriding virtual function has an access (public, protected or private) in the derived class different from the access of the overridden virtual function in the base class. Was this an oversight? Since calls to the overriding virtual function are usually made through the base class, making the access different is unusual (though legal). 1769 Member or base class 'Symbol' has no constructor -- An initializer of the form Symbol() is ignored. Symbol is either a class member with a class, struct, or union type or is a base class. In either case the class (or struct or union) has no constructor and hence what appears to be an initialization is not. See also message 1557. 1770 function 'Symbol' defined without function 'String' -- A typical Info 1770 message is: function 'operator new(unsigned)' defined without function 'operator delete' There are three others: operator delete without an operator new, operator new[] without an operator delete[], and operator delete[] without an operator new[]. In general it is not a good idea to create one of these functions without the other in the pairing. [23, Item 27] You can suppress any of these without suppressing them all. Simply do a -esym(1770,name) where name is the first function named in the message. 1771 function 'Symbol' replaces global function -- This message is given for operator new and operator delete (and for their [] cousins) when a definition for one of these functions is found. Redefining the built-in version of these functions is not considered sound programming practice. [23, Item 27] 1772 Assignment operator 'Symbol' is not returning *this -- The assignment operator should return *this. This is to allow for multiple assignments as in: a = b = c; It is also better to return the object that has just been modified rather than the argument. [12, Item 15] 1773 Attempt to cast away const (or volatile) -- An attempt was made to cast away const. This can break the integrity of the const system. This message will be suppressed if you use const_cast. Thus: char *f( const char * p ) { if( test() ) return (char *) p; // Info 1773 else return const_cast(p); // OK } See [12, Item 21]. 1774 Could use dynamic_cast to downcast ptr to polymorphic type 'Symbol' -- A downcast was detected of a pointer to a polymorphic type (i.e., one with virtual functions). A dynamic_cast could be used to cast this pointer safely. For example: class B { virtual ~B(); }; class D : public B {}; ... D *f( B *p ) { return dynamic_cast(p); } In the above example, if p is not a pointer to a D then the dynamic cast will result in a NULL pointer value. In this way, the validity of the conversion can be directly tested. B needs to be a polymorphic type in order to use dynamic_cast. If B is not polymorphic, message 1939 is issued. 1775 catch block does not catch any declared exception -- A catch handler does not seem to catch any exceptions. For example: try { f(); } catch( B& ) {} catch( D& ) {} // Info 1775 catch( ... ) {} catch( char * ) {} // Info 1775 If f() is declared to throw type D, and if B is a public base class of D, then the first catch handler will process that exception and the second handler will never be used. The fourth handler will also not be used since the third handler will catch all exceptions not caught by the first two. If f() is not declared to throw an exception then Info 1775 will be issued for all four catch handlers. 1776 Converting string literals to char * is deprecated (Context) -- A string literal, according to Standard C++ is typed an array of const char. This message is issued when such a literal is assigned to a non-const pointer. For example: char *p = "string"; will trigger this message. This pointer could then be used to modify the string literal and that could produce some very strange behavior. Such an assignment is legal but "deprecated" by the C++ Standard. The reason for not ruling it illegal is that numerous existing functions have their arguments typed as char * and this would break working code. Note that this message is only given for string literals. If an expression is typed as pointer to const char in some way other than via string literal, then an assignment of that pointer to a non-const pointer will receive a more severe warning. 17.10 C++ Elective Notes 1901 Creating a temporary of type 'Symbol' -- PC-lint/FlexeLint judges that a temporary needs to be created. This occurs, typically, when a conversion is required to a user object (i.e. class object). Where temporaries are created, can be an issue of some concern to programmers seeking a better understanding of how their programs are likely to behave. But compilers differ in this regard. 1902 useless ';' follows '}' in function definition -- It is possible to follow a function body with a useless semi-colon. This is not necessarily 'lint' to be removed but may be a preferred style of programming (as semi-colons are placed at the end of other declarations). 1904 Old-style C comment -- For the real bridge-burner one can hunt down and remove all instances of the /* ... */ form of comment. [12, Item 4] 1905 implicit default constructor generated for class 'Name' -- A default constructor was not defined for a class but a base class or a member has a non-trivial default constructor and so a non-trivial default constructor is generated for this class. 1907 implicit destructor generated for class 'Name' -- The named class does not itself have an explicit destructor but either had a base class that has a destructor or has a member class that has a destructor (or both). In this case a destructor will be generated by the compiler. [11 section 12.4] 1908 'virtual' assumed for destructor'~Name()' (inherited from base class 'Name() -- The destructor cited was inherited from a base class with a virtual destructor. This word 'virtual' was omitted from the declaration. It is common practice to omit this keyword when implied. A warning is issued ( 1512) when a base class's destructor is not virtual. See also 1909. 1909 'virtual' assumed, see: function 'Symbol' (Location) -- The named function overrides a base class virtual function and so is virtual. It is common practice to omit the virtual keyword in these cases although some feel that this leads to sloppy programming. This message allows pro grammers to detect and make explicit which functions are actually virtual. 1911 Implicit call of constructor 'Symbol' (see text) -- The Symbol in the message is the name of a constructor called to make an implicit conversion. This message can be helpful in tracking down hidden sources of inefficiencies. [11 section 12.1] 1912 Implicit call of conversion function from class 'Name' to type 'Type' -- A conversion function (one of the form Symbol::operator Type ()) was implicitly called. This message can be helpful in tracking down hidden sources of inefficiencies. 1914 Default constructor 'Symbol' (Location) not referenced -- A default constructor was not referenced. When a member function of a class is not referenced, you will normally receive an Informational message ( 1714) to that effect. When the member function is the default constructor, however, we give this Elective Note instead. The rationale for this different treatment lay in the fact that many authors recommend defining a default constructor as a general principle. Indeed we give an Informational message ( 1712) when a default constructor is not defined for a class. Therefore, if you are following a modus operandi of not always defining a default constructor you may want to turn off message 1712 and turn on message 1914 instead. 1916 Ellipsis encountered -- An ellipsis was encountered while processing the prototype of some function declaration. An ellipsis is a way of breaking the typing system of C or C++. 1917 empty prototype for definition, assumed '(void)' -- Whereas we give an Informational Message ( 1717) when a (non-member) declaration contains no prototype, we give a much milder Elective Note when a definition does the same. For example: int f(); // Info 1717 int f() { return 1; } // Elective Note 1917 The reason for this is that the declaration form has a different meaning in C and C++. In C it is an incomplete declaration saying nothing about arguments. In C++ the declaration says there are no arguments. The definition, however, means the same in both languages. See also message 1918. [11 section 8.2.5] 1918 empty prototype for member declaration, assumed (void) -- A function declaration within a class contains an empty prototype. This case is similar to Info 1717, which complains about an empty prototype outside a class. It receives a lighter classification (Elective Note) because an empty prototype within a class cannot be ambiguous because C does not allow functions within classes. [11 section 8.2.5] 1919 Multiple assignment operators for class 'Symbol' -- For a given class more than one function was declared whose name was 'operator ='. This is not necessarily a bad thing. For example, a String class may very well have an assignment from char * and such an assignment may be advisable from an efficiency standpoint. However, it represents a loss of elegance because there will almost certainly be a char * constructor and an assignment operator, which will represent another way of achieving the same effect. 1920 Casting to a reference -- The ARM [11] (Section 5.4) states that reference casts are often 'misguided'. However, too many programs are openly using reference casts to place such casts in the Informational category. [11 section 5.4] 1921 Symbol 'Symbol' not checking argument against sizeof(class) -- This note is given for either operator new or operator delete when defined as member functions. As member functions they are called when new (or delete) is applied to a class type or any derived class type. The difficulty is with the derived class type. Any specialized allocator is likely to be useless for a derived class type and hence experts suggest that a test be made of the size_t argument against sizeof(class). Specifically PC-lint/FlexeLint is looking for one of: if( arg == sizeof(class) ) if( arg != sizeof(class) ) if( sizeof(class) == arg ) if( sizeof(class) != arg ) or the equivalent. If any such function is found that is a member of a class that is the base of a derivation, then in addition to Note 1921, we issue Warning 1531. (see Steve Simpson, "More on Memory Management", Dr. Dobb's Journal, August 1994, p. 10). 1922 Symbol 'Symbol' not checking argument for NULL -- This message is given for a function operator delete which is not checking its parameter for being the NULL pointer. We would normally expect to see some such check as: if( arg ) if( arg == 0 ) if( arg != NULL ) etc. Class destructors will normally filter out passing the NULL pointer into the operator delete so that this message is only in the Elective Note category. If there is no destructor you obtain a warning. See Warning 1532. 1923 macro 'Symbol' could become const variable -- The designated macro could probably be replaced by a const variable. A const variable is preferred in some quarters where, for example, a local debugger may not understand macros but would understand variables. [12, Item 1]. The message is issued for macros containing at least one constant or constant equivalent (an earlier const-able macro or const variable) and no other variables or tokens such as ';' of a non-expression nature. 1924 C-style cast -- A C-style cast was detected. This can be replaced by one of the newer C++ casts having the form: Name(Expression) where Name is one of static_cast, dynamic_cast, const_cast or reinterpret_cast. [23, Item 2]. 1925 Symbol 'Symbol' is a public data member -- The indicated Symbol is a public data member of a class. If the class is introduced with the keyword struct the message is not issued. In some quarters the use of public data members is deprecated. The rationale is that if function calls replace data references in the public interface, the implementation can change without affecting the interface. [12, Item 20] 1926 Symbol 'Symbol's default constructor implicitly called -- A member of a class (identified by Symbol) did not appear in the constructor initialization list. Since it had a default constructor this constructor was implicitly called. Is this what the user intended? Some authorities suggest that all members should appear in the constructor initialization list. [12, Item 12]. 1927 Symbol 'Symbol' was not initialized in the constructor initializer list -- A member of a class (identified by Symbol) did not appear in a constructor initialization list. If the item remains uninitialized through the whole of the constructor, a Warning 1401 is issued. Some authorities suggest that all members should appear in the constructor initialization list. [12, Item 12]. 1928 Symbol 'Name' did not appear in the constructor initializer list -- A base class (identified by Symbol) did not appear in a constructor initialization list. If a constructor does not appear, then the default constructor is called. This may or may not be valid behavior. If a base class is missing from a copy constructor's initializer list, then a more severe Warning ( 1538) is issued. [12, Item 12]. 1929 function 'Symbol' returning a reference -- A non-member function was found to be returning a reference. This is not normally considered good practice because responsibility for deleting the object is not easily assigned. [12, Item 23]. 1930 Conversion operator 'Symbol' found -- A conversion operator is a member function of the form: operator Type (); This will be called implicitly by the compiler whenever an object (of the class type) is to be converted to type Type. Some programmers consider such implicit calls to be potentially harmful leading to programming situations that are difficult to diagnose. See for example [23, Item 5]. 1931 Constructor 'Symbol' can be used for implicit conversions -- A constructor was found that could be used for implicit conversions. For example: class X { public: X(int); ... }; Here, any int (or type convertible to int) could be automatically converted to X. This can sometimes cause confusing behavior [23, Item 5]. If this is not what was intended, use the keyword 'explicit' as in: explicit X(int); This will also serve to suppress this message. 1932 Base class 'Symbol' is not abstract. -- An abstract class is a class with at least one pure virtual specifier. At least one author has argued [23, Item 33] that all base classes should be abstract although this suggestion flies in the face of existing practice. 1933 Call to unqualified virtual function 'Symbol' from non-static member function -- A classical C++ gotcha is the calling of a virtual function from within a constructor or a destructor. When we discover a direct call from a constructor or destructor to a virtual function we issue Warning 1506. But what about indirect calls. Suppose a constructor calls a function that in turn, perhaps through several levels of call, calls a virtual function. This could be difficult to detect. Dan Saks [24] has suggested a compromise Guideline that "imposes few, if any, practical restrictions". The Guideline, implemented by this Elective Note, issues a message whenever an unqualified virtual function is called by any other (non-static) member function (for the same 'this' object). For example: class X { virtual void f(); void g(); }; void X::g() { f(); // Note 1933 X::f(); // ok -- non virtual call. } Even if total abstinence is unwarranted, turning on message 1933 occasionally can be helpful in detecting situations when constructors or destructors call virtual functions. 1934 Shift operator 'Symbol' should be non-member function -- It has been suggested [12, Item 19] that you should never make a shift operator a member function unless you're defining ostream or istream (the message is suppressed in these two cases). The reason is that there is a temptation on the part of the novice to, for example, define output to ostream as a class member function left shift that takes ostream as an argument. This is exactly backwards. The shift operator normally employs the destination (or source) on the left. On the other hand, if the class you are defining is the source or destination then defining the shift operators is entirely appropriate. 1935 Dynamic initialization for class object 'Symbol1' (references 'Symbol2') -- A static class-like object whose name is Symbol1 is dynamically initialized by referencing Symbol2 (the latter is normally a constructor for the former). The reason for noting this initialization is that the order of inter-module dynamic initializations is not defined. (Within a module, however, the intializations are done in the order of appearance.) Hence, if the constructor is itself dependent on dynamic initialization occurring in another module the behavior is undefined. For example: class X { X(): ... }; X x: This will elicit Elective Note 1935 that x is being initialized dynamically by a call to X::X(). Now, if this constructor were to be accessing information that depended on the order of evaluation (such as accessing the value of x itself) the result would be undefined. We have no evidence of this at this point. and for this reason the message is in the Elective Note category. However, programmers with a suspected order-of-initialization problem will probably want to turn this on. See also 1936, 1937, 1544 and 1545. 1936 Dynamic initialization for variable 'Symbol1' (references 'Symbol2') -- A static scalar whose name is Symbol1 is dynamically initialized and references Symbol2 during the initialization. For example, let a module consist only of: int f(); int n = f(); Here we report that n is dynamically initialized by f(). There may be other symbols referenced, Symbol2 is just the first. The reason for noting this initialization is that the order of inter-module dynamic initializations is not defined. (Within a module, however, the initializations are done in the order of appearance.) If Symbol2 were a variable, then PC-lint/FlexeLint could determine that the variable is dynamically initialized in another module and issue a 1544 or 1545 as appropriate. However, the symbol referenced could be a function (as in the example) and PC-lint/FlexeLint does not analyze the complete function call graph to determine whether there is a dependency on another dynamic initialization. See also 1935 and 1937. 1937 Static variable 'Symbol' has a destructor. -- A static scalar whose name is Symbol has a destructor. Destructors of static objects are invoked in a predictable order only for objects within the same module (the reverse order of construction). For objects in different modules this order is indeterminate. Hence, if the correct operation of a destructor depends on the existence of an object in some other module an indeterminacy could result. See also 1935, 1936, 1544 and 1545. 1938 constructor 'Symbol' accesses global data. -- A constructor is accessing global data. It is generally not a good idea for constructors to access global data because order of initialization dependencies can be created. If the global data is itself initialized in another module and if the constructor is accessed during initialization, a 'race' condition is established. [12, Item 47] 1939 Down cast detected -- A down cast is a cast from a pointer (or reference) to a base class to a pointer (or reference) to a derived class. A cast down the class hierarchy is fraught with danger. Are you sure that the alleged base class pointer really points to an object in the derived class. Some amount of down casting is necessary but a wise programmer will reduce this to a minimum. [12, Item 39] 1961 virtual member function 'Symbol' could be made const -- This message is similar to message 1762 (member function could be made const) except that it is issued for a virtual function. You may not want to make virtual functions const because then any overriding function would have to be const as well. Consider, for example: class A { virtual void f() {} /* ... */ }; class B : public A { int a; void f() { a = 0; } }; Here, class B overrides A's function f() and, in doing so, modifies member a. If A::f() had been declared const, this would not have been possible. Nonetheless, a particularly rigorous user may want to hunt down such virtual functions and make them all const and so this Note is provided. This message is also similar to Note 1962, which is issued for functions that make deep modifications. Note 1962 takes priority over 1961. That is, a virtual function that makes a deep modification (but no shallow modifications) will have Note 1962 issued but not Note 1961. 1962 Non-const member function 'Symbol' contains a deep modification. -- The designated member function could be declared const but shouldn't be because it contains a deep modification. For example: class X { char *p; public: void f() { *p = 0; } x(); }; will elicit this message indicating that X::f() contains a deep modification. A modification is considered shallow if it modifies (or exposes for modification) a class member directly. A modification is considered deep if it modifies information indirectly through a class member pointer. This Elective Note is available for completeness so that a programmer can find all functions that could result in a class being modified. It does not indicate that the programming is deficient. In particular, if the function is marked const an Info 1763 will be issued. See also 1762, 1763.