2006-05-19  Jakub Jelinek  <jakub@redhat.com>

	* dwarf2out.c (gen_subprogram_die): If -fno-frame-base-loclist,

	set frame base to hard fp or stack pointer.

	* toplev.c (flag_frame_base_loclist): New variable.

	(f_options): Add -fframe-base-loclist.

	* flags.h (flag_frame_base_loclist): New extern.

	* common.opt (frame-base-loclist): New flag.

	* opts.c (common_handle_option): Handle -f{,no-}frame-base-loclist.

--- gcc/dwarf2out.c.jj	2006-05-15 14:02:35.000000000 +0200

+++ gcc/dwarf2out.c	2006-05-15 14:21:40.000000000 +0200

@@ -11389,33 +11389,35 @@ gen_subprogram_die (tree decl, dw_die_re

 #endif

 #ifdef DWARF2_UNWIND_INFO

-      /* We define the "frame base" as the function's CFA.  This is more

-	 convenient for several reasons: (1) It's stable across the prologue

-	 and epilogue, which makes it better than just a frame pointer,

-	 (2) With dwarf3, there exists a one-byte encoding that allows us

-	 to reference the .debug_frame data by proxy, but failing that,

-	 (3) We can at least reuse the code inspection and interpretation

-	 code that determines the CFA position at various points in the

-	 function.  */

-      /* ??? Use some command-line or configury switch to enable the use

-	 of dwarf3 DW_OP_call_frame_cfa.  At present there are no dwarf

-	 consumers that understand it; fall back to "pure" dwarf2 and

-	 convert the CFA data into a location list.  */

-      {

-	dw_loc_list_ref list = convert_cfa_to_loc_list ();

-	if (list->dw_loc_next)

-	  add_AT_loc_list (subr_die, DW_AT_frame_base, list);

-	else

-	  add_AT_loc (subr_die, DW_AT_frame_base, list->expr);

-      }

+      if (flag_frame_base_loclist)

+	{

+	  /* We define the "frame base" as the function's CFA.  This is more

+	     convenient for several reasons: (1) It's stable across the prologue

+	     and epilogue, which makes it better than just a frame pointer,

+	     (2) With dwarf3, there exists a one-byte encoding that allows us

+	     to reference the .debug_frame data by proxy, but failing that,

+	     (3) We can at least reuse the code inspection and interpretation

+	     code that determines the CFA position at various points in the

+	     function.  */

+	  /* ??? Use some command-line or configury switch to enable the use

+	     of dwarf3 DW_OP_call_frame_cfa.  At present there are no dwarf

+	     consumers that understand it; fall back to "pure" dwarf2 and

+	     convert the CFA data into a location list.  */

+	  dw_loc_list_ref list = convert_cfa_to_loc_list ();

+	  if (list->dw_loc_next)

+	    add_AT_loc_list (subr_die, DW_AT_frame_base, list);

+	  else

+	    add_AT_loc (subr_die, DW_AT_frame_base, list->expr);

-      /* Compute a displacement from the "steady-state frame pointer" to

-	 the CFA.  The former is what all stack slots and argument slots

-	 will reference in the rtl; the later is what we've told the

-	 debugger about.  We'll need to adjust all frame_base references

-	 by this displacement.  */

-      compute_frame_pointer_to_cfa_displacement ();

-#else

+	  /* Compute a displacement from the "steady-state frame pointer" to

+	     the CFA.  The former is what all stack slots and argument slots

+	     will reference in the rtl; the later is what we've told the

+	     debugger about.  We'll need to adjust all frame_base references

+	     by this displacement.  */

+	  compute_frame_pointer_to_cfa_displacement ();

+	}

+      else

+#endif

       /* For targets which support DWARF2, but not DWARF2 call-frame info,

 	 we just use the stack pointer or frame pointer.  */

       /* ??? Should investigate getting better info via callbacks, or else

@@ -11425,7 +11427,6 @@ gen_subprogram_die (tree decl, dw_die_re

 	  = frame_pointer_needed ? hard_frame_pointer_rtx : stack_pointer_rtx;

 	add_AT_loc (subr_die, DW_AT_frame_base, reg_loc_descriptor (fp_reg));

       }

-#endif

 #if 0

       /* ??? This fails for nested inline functions, because context_display

--- gcc/toplev.c.jj	2005-11-21 14:55:43.000000000 +0100

+++ gcc/toplev.c	2006-05-15 14:25:14.000000000 +0200

@@ -961,6 +961,10 @@ int flag_tracer = 0;

 int flag_unit_at_a_time = 0;

+/* Nonzero if DWARF2 DW_AT_frame_base can be a location list.  */

+

+int flag_frame_base_loclist = 1;

+

 /* Nonzero if we should track variables.  When

    flag_var_tracking == AUTODETECT_FLAG_VAR_TRACKING it will be set according

    to optimize, debug_info_level and debug_hooks in process_options ().  */

@@ -1165,7 +1169,8 @@ static const lang_independent_options f_

   { "trapv", &flag_trapv, 1 },

   { "wrapv", &flag_wrapv, 1 },

   { "new-ra", &flag_new_regalloc, 1 },

-  { "var-tracking", &flag_var_tracking, 1}

+  { "var-tracking", &flag_var_tracking, 1},

+  { "frame-base-loclist", &flag_frame_base_loclist, 1}

 };

 /* Here is a table, controlled by the tm.h file, listing each -m switch

--- gcc/flags.h.jj	2005-11-21 14:43:20.000000000 +0100

+++ gcc/flags.h	2006-05-15 14:25:06.000000000 +0200

@@ -746,6 +746,9 @@ extern int flag_remove_unreachable_funct

 /* Nonzero if we should track variables.  */

 extern int flag_var_tracking;

+/* Nonzero if DWARF2 DW_AT_frame_base can be a location list.  */

+extern int flag_frame_base_loclist;

+

 /* A string that's used when a random name is required.  NULL means

    to make it really random.  */

--- gcc/common.opt.jj	2005-11-21 08:43:20.000000000 -0500

+++ gcc/common.opt	2006-05-19 06:24:09.000000000 -0400

@@ -718,6 +718,10 @@ fvar-tracking

 Common

 Perform variable tracking

+fframe-base-loclist

+Common

+Allow use of DWARF2 location lists for frame base

+

 fverbose-asm

 Common

 Add extra commentary to assembler output

--- gcc/opts.c.jj	2005-11-21 08:43:21.000000000 -0500

+++ gcc/opts.c	2006-05-19 06:26:26.000000000 -0400

@@ -1461,6 +1461,10 @@ common_handle_option (size_t scode, cons

       flag_var_tracking = value;

       break;

+    case OPT_fframe_base_loclist:

+      flag_frame_base_loclist = value;

+      break;

+

     case OPT_fverbose_asm:

       flag_verbose_asm = value;

       break;