[Bug c++/85385] [8 Regression] Bogus "macro had not yet been defined" message when macro used with wrong arg count

2018-04-12 Thread dmalcolm at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85385

David Malcolm  changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution|--- |FIXED

--- Comment #2 from David Malcolm  ---
Should be fixed by r259360.

[Bug c++/85385] [8 Regression] Bogus "macro had not yet been defined" message when macro used with wrong arg count

2018-04-12 Thread dmalcolm at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85385

--- Comment #1 from David Malcolm  ---
Author: dmalcolm
Date: Thu Apr 12 23:44:09 2018
New Revision: 259360

URL: https://gcc.gnu.org/viewcvs?rev=259360=gcc=rev
Log:
Prevent erroneous "macro had not yet been defined" messages (PR c++/85385)

PR c++/85385 reports an issue where we emit bogus "macro had not yet been
defined" notes when a macro is mis-used:

  $ cat test.c
  #define MACRO(X,Y)

  void test ()
  {
MACRO(42);
  }

  $ ./xg++ -B. -c test.c
  test.c:5:11: error: macro "MACRO" requires 2 arguments, but only 1 given
 MACRO(42);
 ^
  test.c: In function ‘void test()’:
  test.c:5:3: error: ‘MACRO’ was not declared in this scope
 MACRO(42);
 ^
  test.c:5:3: note:
  test.c:1: note: it was later defined here
   #define MACRO(X,Y)

The macro *had* been defined, it was merely misused.

This patch fixes the issue by only issuing the note if the use location
is before the definition location (using linemap_location_before_p).

gcc/cp/ChangeLog:
PR c++/85385
* name-lookup.c (macro_use_before_def::maybe_make): New function,
checking that the use is indeed before the definition.
(macro_use_before_def::macro_use_before_def): Make private.
(macro_use_before_def::~macro_use_before_def): Make private.  Move
check for UNKNOWN_LOCATION to macro_use_before_def::maybe_make.
(lookup_name_fuzzy): Call macro_use_before_def::maybe_make rather
than using new directly.

gcc/testsuite/ChangeLog:
PR c++/85385
* g++.dg/diagnostic/macro-arg-count.C: New test.


Added:
trunk/gcc/testsuite/g++.dg/diagnostic/macro-arg-count.C
Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/name-lookup.c
trunk/gcc/testsuite/ChangeLog