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C

C static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C code

  • All rules 315
  • Vulnerability13
  • Bug76
  • Security Hotspot19
  • Code Smell207

  • Quick Fix 19
Filtered: 37 rules found
suspicious
    Impact
      Clean code attribute
        1. "offsetof" macro should not be used

           Code Smell
        2. "errno" should not be used

           Code Smell
        3. Function names should be used either as a call with a parameter list or with the "&" operator

           Code Smell
        4. "enum" values should not be used as operands to built-in operators other than [ ], =, ==, !=, unary &, and the relational operators <, <=, >, >=

           Code Smell
        5. "bool" expressions should not be used as operands to built-in operators other than =, &&, ||, !, ==, !=, unary &, and the conditional operator

           Code Smell
        6. A cast shall not remove any const or volatile qualification from the type of a pointer or reference

           Code Smell
        7. Trigraphs should not be used

           Code Smell
        8. "#pragma pack" should be used correctly

           Bug
        9. Only valid arguments should be passed to UNIX/POSIX functions

           Code Smell
        10. Only valid arguments should be passed to stream functions

           Code Smell
        11. "^" should not be confused with exponentiation

           Code Smell
        12. Size of variable length arrays should be greater than zero

           Code Smell
        13. "mktemp" family of functions templates should have at least six trailing "X"s

           Code Smell
        14. Unevaluated operands should not have side effects

           Code Smell
        15. Size argument of memory functions should be consistent

           Code Smell
        16. Return value of "nodiscard" functions should not be ignored

           Code Smell
        17. Implicit casts should not lower precision

           Code Smell
        18. Appropriate size arguments should be passed to "strncat" and "strlcpy"

           Code Smell
        19. User-defined types should not be passed as variadic arguments

           Bug
        20. Array values should not be replaced unconditionally

           Bug
        21. A conditionally executed single line should be denoted by indentation

           Code Smell
        22. Conditionals should start on new lines

           Code Smell
        23. "case" ranges should cover multiple values

           Code Smell
        24. "switch" statements should cover all cases

           Code Smell
        25. Redundant pointer operator sequences should be removed

           Code Smell
        26. Conditionally executed code should be reachable

           Bug
        27. Flexible array members should not be declared

           Code Smell
        28. Track parsing failures

           Code Smell
        29. Recursion should not be infinite

           Bug
        30. Two branches in a conditional structure should not have exactly the same implementation

           Code Smell
        31. Pre-defined macros should not be defined, redefined or undefined

           Code Smell
        32. Switch cases should end with an unconditional "break" statement

           Code Smell
        33. "switch" statements should not contain non-case labels

           Code Smell
        34. Methods should not be empty

           Code Smell
        35. Assignments should not be made from within conditions

           Code Smell
        36. Variables should not be shadowed

           Code Smell
        37. Nested blocks of code should not be left empty

           Code Smell

        "#pragma pack" should be used correctly

        intentionality - logical
        reliability
        Bug
        • suspicious

        Why is this an issue?

        #pragma pack is a non-standard extension that specifies the packing alignment for structure, union, and class members.

        It is useful to

        • remove padding and decrease the size of objects
        • align members to better fit optimal cpu alignment

        However, the pragma pack directives need to be correctly defined to work properly.

        This rule raises an issue if:

        • the specified packing value is incorrect: it can only be 1, 2, 4, 8, or 16
        • a parameter is ill-formed
        • the pop variant of this #pragma is called with both arguments identifier and value: such a call is undefined behavior
        • a #pragma pack(push...) is performed but there is not corresponding use of #pragma pack(pop...)
        • a #pragma pack(pop...) is performed but there is not corresponding use of #pragma pack(push...)
        • a #pragma pack is in effect across several files: this becomes too complex and could easily lead to undefined behavior, the same structure having a different layout when seen from different translation units

        Noncompliant code example

        #pragma pack(5) // Noncompliant, value is invalid
        #pragma pack(2+2) // Noncompliant, value should be a literal
        
        #pragma pack(4)
        #include "myFile.h" // Noncompliant, the specified alignment value will be applied to this file
        
        struct T {
           int i;
           short j;
           double k;
        };
        
        #pragma pack(push, r1, 16)
        #pragma pack(pop, r1, 4)  // Noncompliant, call to pop with two arguments is undefined
        
        #pragma pack(push, r2, 16) // Noncompliant, call to push with no matching pop
        #pragma pack(pop, r3)  // Noncompliant, call to pop with no matching push
        
        #pragma pack(push, 8) // Noncompliant, unmatched push
        

        Compliant solution

        #include "myFile.h"
        
        #pragma pack(4)
        
        struct T {
           int i;
           short j;
           double k;
        };
        
        #pragma pack(push, r1, 16)
        #pragma pack(pop, r1)
        
        #pragma pack(push, r2, 16)
        #pragma pack(pop, r2)
        
        #pragma pack(push, 8)
        #pragma pack(pop)
        
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