[SOLVED] Split function-like macro call between two source files

Issue

Is there anything in the C Standard preventing me of doing the following?

// main.c
#define DECORATE(x) ***x***
#include "call_macro.h"
this is the text I want decorated)

// call_macro.h
DECORATE(

When running it though gcc -E main.c, I expected to get

*** this is the text I want decorated***

Instead, it complained about macro_call.h:2: error: unterminated argument list invoking macro "DECORATE", but I can't actually find any prohibition of it in the standard.

Thoughts?

Solution

5.1.1.2 Translation phases
(1.4) Preprocessing directives are executed, macro invocations are expanded, and _Pragma unary operator expressions are executed... A #include preprocessing directive causes the named header or source file to be processed from phase 1 through phase 4, recursively. All preprocessing directives are then deleted.

I believe this says that each included header is preprocessed separately, before being "merged" into the overall translation unit. It is at this point that an incomplete function-like macro invocation would be ill-formed:

6.10.3/4 ... There shall exist a ) preprocessing token that terminates the invocation.

Answered By - Igor Tandetnik