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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
 
Tags
    Impact
      Clean code attribute
        1. Pointer and reference parameters should be "const" if the corresponding object is not modified

           Code Smell
        2. Non-standard characters should not occur in header file names in "#include" directives

           Bug
        3. Functions should not be declared at block scope

           Code Smell
        4. Literal suffix "L" for long integers shall be upper case

           Code Smell
        5. Digraphs should not be used

           Code Smell
        6. The first element of an array should not be accessed implicitly

           Code Smell
        7. A single L in a literal suffix should only be used for long values

           Code Smell
        8. Loop variables should be declared in the minimal possible scope

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

           Code Smell
        10. "sizeof" should not be called on pointers

           Bug
        11. Control characters should not be used in literals

           Code Smell
        12. Parameters should be passed in the correct order

           Code Smell
        13. Redundant casts should not be used

           Code Smell
        14. Multiple variables should not be declared on the same line

           Code Smell
        15. Unused local variables should be removed

           Code Smell
        16. Octal values should not be used

           Code Smell
        17. A "while" loop should be used instead of a "for" loop

           Code Smell
        18. Sections of code should not be commented out

           Code Smell
        19. Redundant pairs of parentheses should be removed

           Code Smell

        Functions should not be declared at block scope

        intentionality - clear
        maintainability
        Code Smell
        Quick FixIDE quick fixes available with SonarLint
        • misra-c++2008
        • misra-c2004

        Why is this an issue?

        How can I fix it?

        More Info

        It is rarely useful to declare a function at block scope. Such a function will not get special access to any name in its enclosing scope, and therefore, it is equivalent but clearer to declare it instead in the enclosing namespace.

        Additionally, when a function is declared at block scope, the intent is often not to declare a function but instead to declare and initialize a variable. This problem is nicknamed the most vexing parse and stems from the fact that some syntaxes can be ambiguous, and that in that case the language unintuitively favors function declaration:

        void f() {
          int a;
          string b();
          short c(short (a));
        }
        
        • b could be interpreted as:
          • A variable of type string with empty initialization or
          • A function with no argument and returning a string.
          The second interpretation is selected.
        • Similarly, c could be interpreted as:
          • A variable of type short initialized with the value a converted to short or
          • A function that takes a parameter named a (with extra parentheses) of type short and returning a short
          Here again, the second interpretation is selected.

        There are several ways to write the code differently so that b and c can only be interpreted as variables. For instance:

        void f() {
          int a;
          string b {};
          auto c = short (a);
        }
        

        By raising issues on local function declaration, this rule helps detect when a function is inadvertently declared.

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          Developer Edition
          Available Since
          9.1

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