===== Links =====

  * [[https://wiki.sei.cmu.edu/confluence/display/c]]

===== Preprocessor (PRE) =====

==== 2.1 PRE30-C. Do not create a universal character name through concatenation ====

==== 2.2 PRE31-C. Avoid side effects in arguments to unsafe macros ====

An unsafe function-like macro is one whose expansion results in evaluating one of its parameters more than once or not at all.

<code>
#define ABS(x) (((x) < 0) ? -(x) : (x)) /* UNSAFE */
  
void func(int n) {
  /* Validate that n is within the desired range */
  ++n;
  int m = ABS(n);
 
  /* ... */
}
</code>
==== 2.3 PRE32-C. Do not use preprocessor directives in invocations of function-like macros ====

The arguments to a macro must not include preprocessor directives, such as #define, #ifdef, and #include.

<code>
void func(const char *src) {
  /* Validate the source string; calculate size */
  char *dest;
  /* malloc() destination string */
  memcpy(dest, src,
    #ifdef PLATFORM1
      12
    #else
      24
    #endif
  );
  /* ... */
}
</code>

===== 3 Declarations and Initialization (DCL) =====

==== 3.1 DCL30-C. Declare objects with appropriate storage durations ====

==== 3.2 DCL31-C. Declare identifiers before using them ====

==== 3.3 DCL36-C. Do not declare an identifier with conflicting linkage classifications ====

==== 3.4 DCL37-C. Do not declare or define a reserved identifier ====

==== 3.5 DCL38-C. Use the correct syntax when declaring a flexible array member ====

  * The incomplete array type must be the last element within the structure.
  * There cannot be an array of structures that contain a flexible array member.
  * Structures that contain a flexible array member cannot be used as a member of another structure.
  * The structure must contain at least one named member in addition to the flexible array member.

<code>
struct flexArrayStruct{
  int num;
  int data[];
};
</code>
==== 3.6 DCL39-C. Avoid information leakage when passing a structure across a trust boundary ====

==== 3.7 DCL40-C. Do not create incompatible declarations of the same function or object ====

==== 3.8 DCL41-C. Do not declare variables inside a switch statement before the first case label ====