QA·C Help - 0859

	0859	[L] Number of arguments in macro call exceeds 31 - program does not conform strictly to ISO:C90.

ISO C90 Conformance limits		REFERENCE - ISO:C90-5.2.4.1 Translation Limits

The translation limits specified in the ISO:C Standard define a minimum set of conditions which a compiler must support in order to be described as conforming. In practice, compilers will often tolerate code which exceeds these minimal requirements. However, in order to ensure portability, it is advisable to avoid writing code that assumes a level of compiler capability which may not always be supported.

Message 0859 identifies the situation where a function-like macro has been called with more than 31 arguments, the minimum requirement of the ISO:C90 Standard. This message is not identifying incorrect code but does identify code which is described in the standard as not strictly conforming.

For example:


/*PRQA S 2017,3205,3408,3429,3453 ++*/

#define MAC(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,aa,bb,cc,dd,ee,ff) 1  /* Message 0858 */

extern void foo(void)
{
    int i =  MAC(1,1,1,1,1,1,1,1,1,1,
                 1,1,1,1,1,1,1,1,1,1,
                 1,1,1,1,1,1,1,1,1,1,
                 1,1);                                                                /* Message 0859 */

}

MISRA C:2012 Rules applicable to message 0859:

Dir-1.1 (Required)

Any implementation-defined behaviour on which the output of the program depends shall be documented and understood