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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
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  • Code Smell207

  • Quick Fix 19
Filtered: 17 rules found
bad-practice
    Impact
      Clean code attribute
        1. Pointer and reference parameters should be "const" if the corresponding object is not modified

           Code Smell
        2. Reserved identifiers should not be defined or declared

           Code Smell
        3. Only standard forms of the "defined" directive should be used

           Code Smell
        4. Function-like macros should not be used

           Code Smell
        5. Recursion should not be used

           Code Smell
        6. "continue" should not be used

           Code Smell
        7. Bitwise operators should not be applied to signed operands

           Bug
        8. Functions should be declared explicitly

           Code Smell
        9. Names of well-known C standard library macros and functions should not be used as identifiers

           Code Smell
        10. Macros should not be used as replacements for "typedef" and "using"

           Code Smell
        11. Size of bit fields should not exceed the size of their types

           Code Smell
        12. Pointer and reference local variables should be "const" if the corresponding object is not modified

           Code Smell
        13. Argument of "printf" should be a format string

           Code Smell
        14. Loops with at most one iteration should be refactored

           Bug
        15. "if" statements should be preferred over "switch" when simpler

           Code Smell
        16. Track uses of "NOSONAR" comments

           Code Smell
        17. Deprecated attributes should include explanations

           Code Smell

        Function-like macros should not be used

        intentionality - clear
        maintainability
        Code Smell
        • cppcoreguidelines
        • based-on-misra
        • preprocessor
        • bad-practice
        • cert

        Why is this an issue?

        More Info

        Even if function-like macros may look similar to functions, they work differently. For example, functions provide parameter type-checking, whereas macros do not. Furthermore, since macros result in textual replacements, the code within a macro argument may be evaluated multiple times or in unexpected ways.

        Generally, functions provide a more secure and reliable mechanism than function-like macros. This safety usually outweighs the speed advantages allegedly offered by macros. Therefore, whenever possible, functions should be preferred.

        Noncompliant code example

        #define CUBE (X) ((X) * (X) * (X)) // Noncompliant
        
        void func(void) {
          int i = 2;
          int a = CUBE(++i); // Noncompliant. Expands to: int a = ((++i) * (++i) * (++i))
          // ...
        }
        

        Compliant solution

        inline int cube(int i) {
          return i * i * i;
        }
        
        void func(void) {
          int i = 2;
          int a = cube(++i); // yields 27
          // ...
        }
        

        Exceptions

        In a few situations, actual functions can’t replace function-like macros because the macro relies on features that only work with textual replacement. For instance:

        • Using manipulation of tokens, such as ## (token-pasting) and # (stringification).
        • Getting information about the context into which the macro is expanded by using __FILE__, __LINE__, __func__, or other similar compiler-specific constructs. Note that C++20 std::source_location can be a good replacement for some of these use cases — see S6190.

        This rule will ignore macros that make use of those features.

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