[Bug c/57653] filename information discarded when using -imacros

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57653

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

--- Comment #18 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
Thanks!

I think I know the reason why it is failing, but I am not sure about the proper
fix. 

For some reason unknown to me, push_commandline_include should not be called
while processing -imacros. -imacros tries to achieve this but playing tricks
with include_cursor, but that doesn't stop the pre-included files. Calling
cpp_push_include (or cpp_push_default_include) seems to mess up everything
(again, no idea why!). This code is really a mess but the simple patch below
seems to work. Could you test it?


Index: gcc/c-family/c-opts.c
===================================================================
--- gcc/c-family/c-opts.c       (revision 200330)
+++ gcc/c-family/c-opts.c       (working copy)
@@ -1338,10 +1338,14 @@ c_finish_options (void)

 /* Give CPP the next file given by -include, if any.  */
 static void
 push_command_line_include (void)
 {
+  // This can happen if disabled by -imacros for example.
+  if (include_cursor > deferred_count)
+    return;
+
   if (!done_preinclude)
     {
       done_preinclude = true;
       if (flag_hosted && std_inc && !cpp_opts->preprocessed)
        {