[incremental] Patch: FYI: linemap -vs- free

[Tom Tromey]

I'm checking this in on the incremental-compiler branch.

When I added a realloc function to the line map I neglected to add a
free function.  This isn't really needed -- gcc proper does not ever
call linemap_free -- but it is good to have internal consistency.

The trunk needs this as well, I'll do it sooner or later.

Tom

libcpp/ChangeLog:
2008-04-18  Tom Tromey  <tromey@redhat.com>

	* line-map.c (linemap_free): Use free function.
	* include/line-map.h (line_map_free): New typedef.
	(struct line_maps) <freer>: New field.

gcc/ChangeLog:
2008-04-18  Tom Tromey  <tromey@redhat.com>

	* toplev.c (free_for_line_map): New function.
	(general_init): Use it.

Index: libcpp/line-map.c
===================================================================
--- libcpp/line-map.c	(revision 132956)
+++ libcpp/line-map.c	(working copy)
@@ -64,9 +64,11 @@
 {
   if (set->maps)
     {
+      line_map_free free_fn = set->freer ? set->freer : free;
+
       linemap_check_files_exited (set);
 
-      free (set->maps);
+      (*free_fn) (set->maps);
     }
 }
 
Index: libcpp/include/line-map.h
===================================================================
--- libcpp/include/line-map.h	(revision 132956)
+++ libcpp/include/line-map.h	(working copy)
@@ -1,5 +1,5 @@
 /* Map logical line numbers to (source file, line number) pairs.
-   Copyright (C) 2001, 2003, 2004, 2007
+   Copyright (C) 2001, 2003, 2004, 2007, 2008
    Free Software Foundation, Inc.
 
 This program is free software; you can redistribute it and/or modify it
@@ -42,6 +42,9 @@
 /* Memory allocation function typedef.  Works like xrealloc.  */
 typedef void *(*line_map_realloc) (void *, size_t);
 
+/* Type of function used for freeing memory.  Works like free.  */
+typedef void (*line_map_free) (void *);
+
 /* Physical source file TO_FILE at line TO_LINE at column 0 is represented
    by the logical START_LOCATION.  TO_LINE+L at column C is represented by
    START_LOCATION+(L*(1<<column_bits))+C, as long as C<(1<<column_bits),
@@ -102,6 +105,8 @@
   /* If non-null, the allocator to use when resizing 'maps'.  If null,
      xrealloc is used.  */
   line_map_realloc reallocator;
+  /* Likewise, used for freeing.  */
+  line_map_free freer;
 };
 
 /* Initialize a line map set.  */
Index: gcc/toplev.c
===================================================================
--- gcc/toplev.c	(revision 134400)
+++ gcc/toplev.c	(working copy)
@@ -1716,6 +1716,13 @@
   return ggc_realloc (ptr, len);
 }
 
+/* A helper function used to release memory for cpp's line table.  */
+static void
+free_for_line_map (void *mem ATTRIBUTE_UNUSED)
+{
+  /* Do nothing, the GC will handle it.  */
+}
+
 /* Initialization of the front end environment, before command line
    options are parsed.  Signal handlers, internationalization etc.
    ARGV0 is main's argv[0].  */
@@ -1777,6 +1784,7 @@
   line_table = GGC_NEW (struct line_maps);
   linemap_init (line_table);
   line_table->reallocator = realloc_for_line_map;
+  line_table->freer = free_for_line_map;
   linemap_add (line_table, LC_RENAME, 0, 0, _("<built-in>"), 0);
   loc = linemap_line_start (line_table, 0, 1);
   gcc_assert (loc == BUILTINS_LOCATION);