[Ada] Re-enable -feliminate-unused-debug-types by default

[Eric Botcazou <ebotcazou at adacore dot com>]

The previous 7 patches paved the way to enabling -feliminate-unused-debug-types 
again by default in Ada.  We measured a 12.5% reduction in debug info size on 
one big application (and an even larger one for another application), as well 
as a 0.5% reduction in compilation time at -O0 -g.

Tested on i586-suse-linux, applied on the mainline.


2011-04-02  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/lang.opt (feliminate-unused-debug-types): Delete.
	* gcc-interface/misc.c (gnat_handle_option): Remove special handling
	code for -feliminate-unused-debug-types
	(gnat_post_options): Likewise.


-- 
Eric Botcazou

Index: gcc-interface/lang.opt
===================================================================
--- gcc-interface/lang.opt	(revision 171818)
+++ gcc-interface/lang.opt	(working copy)
@@ -1,5 +1,5 @@
 ; Options for the Ada front end.
-; Copyright (C) 2003, 2007, 2008, 2010 Free Software Foundation, Inc.
+; Copyright (C) 2003, 2007, 2008, 2010, 2011 Free Software Foundation, Inc.
 ;
 ; This file is part of GCC.
 ;
@@ -94,12 +94,6 @@ nostdlib
 Ada
 ; Don't look for object files
 
-feliminate-unused-debug-types
-Ada
-; Effect documented for C - intercepted for Ada to force the associated flag
-; not to be set by default, as it currently eliminates unreferenced parallel
-; types we need for encoding descriptions to the debugger.
-
 fRTS=
 Ada Joined RejectNegative
 ; Selects the runtime
Index: gcc-interface/misc.c
===================================================================
--- gcc-interface/misc.c	(revision 171862)
+++ gcc-interface/misc.c	(working copy)
@@ -125,14 +125,6 @@ gnat_handle_option (size_t scode, const
       /* These are used in the GCC Makefile.  */
       break;
 
-    case OPT_feliminate_unused_debug_types:
-      /* We arrange for post_option to be able to only set the corresponding
-	 flag to 1 when explicitly requested by the user.  We expect the
-	 default flag value to be either 0 or positive, and expose a positive
-	 -f as a negative value to post_option.  */
-      flag_eliminate_unused_debug_types = -value;
-      break;
-
     case OPT_gant:
       warning (0, "%<-gnat%> misspelled as %<-gant%>");
 
@@ -232,8 +224,7 @@ enum stack_check_type flag_stack_check =
 static bool
 gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 {
-  /* Excess precision other than "fast" requires front-end
-     support.  */
+  /* Excess precision other than "fast" requires front-end support.  */
   if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD
       && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)
     sorry ("-fexcess-precision=standard for Ada");
@@ -245,14 +236,6 @@ gnat_post_options (const char **pfilenam
   /* No psABI change warnings for Ada.  */
   warn_psabi = 0;
 
-  /* Force eliminate_unused_debug_types to 0 unless an explicit positive
-     -f has been passed.  This forces the default to 0 for Ada, which might
-     differ from the common default.  */
-  if (flag_eliminate_unused_debug_types < 0)
-    flag_eliminate_unused_debug_types = 1;
-  else
-    flag_eliminate_unused_debug_types = 0;
-
   optimize = global_options.x_optimize;
   optimize_size = global_options.x_optimize_size;
   flag_compare_debug = global_options.x_flag_compare_debug;