Does C have __func__ functionality for names of the arguments of a function?

Question

Does the "C" standard support something similar to __func__ for the function arguments' names?

Answer 1

No, the C99 standard has the following:

6.10.8 Predefined macro names

The following macro names shall be defined by the implementation:

__DATE__ 
__FILE__ 
__LINE__ 
__STDC__ 
__STDC_HOSTED__ 
__STDC_MB_MIGHT_NEQ_WC__ 
__STDC_VERSION__ 
__TIME__ 

The following macro names are conditionally defined by the implementation:

__STDC_IEC_559__ 
__STDC_IEC_559_COMPLEX__ 
__STDC_ISO_10646__ 

6.4.2.2 Predefined identifiers

The identifier __func__ shall be implicitly declared by the translator as if, immediately following the opening brace of each function definition, the declaration

     static const char __func__[] = "function-name";

appeared, where function-name is the name of the lexically-enclosing function.63)

gcc adds some extensions, as I imagine other compilers do.

Answer 2

if you want a quick and dirty solution for this make pre-processor macros like this...

#define FUNCTION_HEADER(a) a { const char* __func__ = #a;
#define FUNCTION_FOOTER() }

... and use it for your function headers and footers like this (tested with VS 2008):

#include <windows.h>

#define FUNCTION_HEADER(a) a { const char* __func__ = #a;
#define FUNCTION_FOOTER() }

FUNCTION_HEADER( int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) )
    MessageBoxA(0, __func__, __func__, MB_OK);
    return 0;
FUNCTION_FOOTER()

This should work exactly how you want, but it is ugly.