[Bug c/61803] New: error reports macro location first, but should not

["tromey at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61803

            Bug ID: 61803
           Summary: error reports macro location first, but should not
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tromey at gcc dot gnu.org

This is not really a C-specific bug but I wasn't sure
where else to file it.

Consider this source:

#define Nil ((int *) 0)

double *fun(void)
{
  return Nil;
}


Now compile:

barimba. gcc --syntax-only q.c
q.c: In function âfunâ:
q.c:1:13: warning: return from incompatible pointer type
[-Wincompatible-pointer-types]
 #define Nil ((int *) 0)
             ^
q.c:5:10: note: in expansion of macro âNilâ
   return Nil;
          ^


I think the "warning" and the "note" should be switched here.

Some tools -- e.g., emacs -- prioritize different output from the
compiler differently.  By default emacs' next-error will take one
to the errors and warnings, but skip the "note"s.  This seems
reasonable enough to me.  However, for the above output, this means
skipping the spot that is probably the cause of the error.

I think instead it would be better to emit the warning at the "final"
location and then print the macro definition information as notes.