[Bug c/91669] New: #pragma's and _Pragma's work but _Pragma's used in an equivalent macro don't

[pskocik at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91669

            Bug ID: 91669
           Summary: #pragma's and _Pragma's work but _Pragma's used in an
                    equivalent macro don't
           Product: gcc
           Version: 5.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pskocik at gmail dot com
  Target Milestone: ---

The problem appears to exist on all gcc versions.

Example Code:

#define BX_gcc_push(Category,...) BX_pragma(GCC Category push ) BX_pragma(GCC
Category __VA_ARGS__)
#define BX_gcc_pop(Category) BX_pragma(GCC Category pop)
#define BX_nodiag_push(DiagStr) BX_gcc_push(diagnostic, ignored DiagStr)
#define BX_nodiag_pop() BX_gcc_pop(diagnostic)
#define BX_pragma(...) _Pragma(#__VA_ARGS__)


int foo(void)
{

//This silences -Wreturn-type on the closing curly as it should
BX_nodiag_push("-Wreturn-type")
}
BX_nodiag_pop()



#define BX_retundef(Rbr) /*{{{*/ \
        BX_nodiag_push("-Wreturn-type") \
        Rbr \
        BX_nodiag_pop()
        /*}}}*/

int bar(void)
{
//This FAILS to silence -Wreturn on the closing curly
//(works on clang and the code obtained from text-expanding the macro (gcc -E)
//works on gcc too) 
BX_retundef(})