re PR middle-end/56461 (GCC is leaking lots of memory)

	PR middle-end/56461
	* internal.h (struct cpp_buffer): Add to_free field.
	(_cpp_pop_file_buffer): Add third argument.
	* files.c (_cpp_stack_file): Set buffer->to_free.
	(_cpp_pop_file_buffer): Add to_free argument.  Free to_free
	if non-NULL, and if equal to file->buffer_start, also clear
	file->buffer{,_start,_valid}.
	* directives.c (_cpp_pop_buffer): Pass buffer->to_free
	to _cpp_pop_file_buffer.

From-SVN: r196497

libcpp/ChangeLog

+2013-03-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/56461
+	* internal.h (struct cpp_buffer): Add to_free field.
+	(_cpp_pop_file_buffer): Add third argument.
+	* files.c (_cpp_stack_file): Set buffer->to_free.
+	(_cpp_pop_file_buffer): Add to_free argument.  Free to_free
+	if non-NULL, and if equal to file->buffer_start, also clear
+	file->buffer{,_start,_valid}.
+	* directives.c (_cpp_pop_buffer): Pass buffer->to_free
+	to _cpp_pop_file_buffer.
+
 2013-03-01  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/56461

libcpp/directives.c

@@ -2558,6 +2558,7 @@ _cpp_pop_buffer (cpp_reader *pfile)
   cpp_buffer *buffer = pfile->buffer;
   struct _cpp_file *inc = buffer->file;
   struct if_stack *ifs;
+  const unsigned char *to_free;
 
   /* Walk back up the conditional stack till we reach its level at
      entry to this file, issuing error messages.  */
@@ -2571,6 +2572,7 @@ _cpp_pop_buffer (cpp_reader *pfile)
   /* _cpp_do_file_change expects pfile->buffer to be the new one.  */
   pfile->buffer = buffer->prev;
 
+  to_free = buffer->to_free;
   free (buffer->notes);
 
   /* Free the buffer object now; we may want to push a new buffer
@@ -2579,7 +2581,7 @@ _cpp_pop_buffer (cpp_reader *pfile)
 
   if (inc)
     {
-      _cpp_pop_file_buffer (pfile, inc);
+      _cpp_pop_file_buffer (pfile, inc, to_free);
 
       _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);
     }

libcpp/files.c

@@ -894,6 +894,7 @@ _cpp_stack_file (cpp_reader *pfile, _cpp_file *file, bool import)
 			    && !CPP_OPTION (pfile, directives_only));
   buffer->file = file;
   buffer->sysp = sysp;
+  buffer->to_free = file->buffer_start;
 
   /* Initialize controlling macro state.  */
   pfile->mi_valid = true;
@@ -1435,7 +1436,8 @@ cpp_push_default_include (cpp_reader *pfile, const char *fname)
 /* Do appropriate cleanup when a file INC's buffer is popped off the
    input stack.  */
 void
-_cpp_pop_file_buffer (cpp_reader *pfile, _cpp_file *file)
+_cpp_pop_file_buffer (cpp_reader *pfile, _cpp_file *file,
+		      const unsigned char *to_free)
 {
   /* Record the inclusion-preventing macro, which could be NULL
      meaning no controlling macro.  */
@@ -1445,12 +1447,15 @@ _cpp_pop_file_buffer (cpp_reader *pfile, _cpp_file *file)
   /* Invalidate control macros in the #including file.  */
   pfile->mi_valid = false;
 
-  if (file->buffer_start)
+  if (to_free)
     {
-      free ((void *) file->buffer_start);
-      file->buffer_start = NULL;
-      file->buffer = NULL;
-      file->buffer_valid = false;
+      if (to_free == file->buffer_start)
+	{
+	  file->buffer_start = NULL;
+	  file->buffer = NULL;
+	  file->buffer_valid = false;
+	}
+      free ((void *) to_free);
     }
 }
 

libcpp/internal.h

@@ -301,6 +301,8 @@ struct cpp_buffer
 
   const unsigned char *buf;        /* Entire character buffer.  */
   const unsigned char *rlimit;     /* Writable byte at end of file.  */
+  const unsigned char *to_free;	   /* Pointer that should be freed when
+				      popping the buffer.  */
 
   _cpp_line_note *notes;           /* Array of notes.  */
   unsigned int cur_note;           /* Next note to process.  */
@@ -635,7 +637,8 @@ extern int _cpp_compare_file_date (cpp_reader *, const char *, int);
 extern void _cpp_report_missing_guards (cpp_reader *);
 extern void _cpp_init_files (cpp_reader *);
 extern void _cpp_cleanup_files (cpp_reader *);
-extern void _cpp_pop_file_buffer (cpp_reader *, struct _cpp_file *);
+extern void _cpp_pop_file_buffer (cpp_reader *, struct _cpp_file *,
+				  const unsigned char *);
 extern bool _cpp_save_file_entries (cpp_reader *pfile, FILE *f);
 extern bool _cpp_read_file_entries (cpp_reader *, FILE *);
 extern const char *_cpp_get_file_name (_cpp_file *);