[PATCH] Fix #pragma implementation diagnostics (PR c++/69145, take 2)

[Jakub Jelinek]

Hi!

On Tue, Jan 05, 2016 at 03:19:04PM -0500, David Malcolm wrote:
> Isn't the line_table available from the cpp_reader as a field, though?
> cpp_included_before could in theory access pfile->line_table.

You are right, that works too.
So I'm offering an alternate patch too:

2016-01-07  Jakub Jelinek  <ja...@redhat.com>

        PR c++/69145
        * files.c (cpp_included_before): If IS_ADHOC_LOC (location), lookup
        real location from the line_table.

        * g++.dg/ext/pr69145-1.C: New test.
        * g++.dg/ext/pr69145-2-very-long-filename.cc: New file.
        * g++.dg/ext/pr69145-2.h: New file.

--- libcpp/files.c.jj   2016-01-05 12:26:58.000000000 +0100
+++ libcpp/files.c      2016-01-07 10:01:35.958676922 +0100
@@ -1224,10 +1224,16 @@ bool
 cpp_included_before (cpp_reader *pfile, const char *fname,
                     source_location location)
 {
-  struct cpp_file_hash_entry *entry;
+  struct cpp_file_hash_entry *entry
+    = (struct cpp_file_hash_entry *)
+      htab_find_with_hash (pfile->file_hash, fname, htab_hash_string (fname));
 
-  entry = (struct cpp_file_hash_entry *)
-     htab_find_with_hash (pfile->file_hash, fname, htab_hash_string (fname));
+  if (IS_ADHOC_LOC (location))
+    {
+      location &= MAX_SOURCE_LOCATION;
+      location
+       = pfile->line_table->location_adhoc_data_map.data[location].locus;
+    }
 
   while (entry && (entry->start_dir == NULL || entry->u.file->err_no
                   || entry->location > location))
--- gcc/testsuite/g++.dg/ext/pr69145-1.C.jj     2016-01-05 12:22:58.206729760 
+0100
+++ gcc/testsuite/g++.dg/ext/pr69145-1.C        2016-01-05 12:22:52.017818392 
+0100
@@ -0,0 +1,4 @@
+// PR c++/69145
+// { dg-do compile }
+#pragma implementation "pr69145-2-very-long-filename.cc" // { dg-bogus 
"appears after file is included" }
+#include "pr69145-2-very-long-filename.cc"
--- gcc/testsuite/g++.dg/ext/pr69145-2-very-long-filename.cc.jj 2016-01-05 
12:23:47.151028824 +0100
+++ gcc/testsuite/g++.dg/ext/pr69145-2-very-long-filename.cc    2016-01-05 
12:23:42.629093583 +0100
@@ -0,0 +1,3 @@
+// PR c++/69145
+// { dg-do compile } */
+#include "pr69145-2.h"
--- gcc/testsuite/g++.dg/ext/pr69145-2.h.jj     2016-01-05 12:23:49.963988539 
+0100
+++ gcc/testsuite/g++.dg/ext/pr69145-2.h        2016-01-05 12:06:42.000000000 
+0100
@@ -0,0 +1,3 @@
+#ifndef PR69145_2_H
+# define PR69145_2_H
+#endif

        Jakub