[patch] [entryval] fixup: Unhandled dwarf expression opcode 0xf3

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

Hi,

with GCC HEAD (4.7.0 experimental) GDB now prints:
Breakpoint 1, 0x00000000004004b8 in f (param=Unhandled dwarf expression opcode 0xf3
)
instead of:
Breakpoint 1, 0x00000000004004b8 in f (param=<optimized out>)

With archer-jankratochvil-entryval it prints the correct calculated parameter
value.  But archer-jankratochvil-entryval still needs some cleanups and it will
not make it in gdb-7.3.  And even if not gdb-7.3 it is disturbing with FSF GDB
HEAD for FSF GCC HEAD, therefore providing at least this quick hack as
a temporary solution.

No regressions on {x86_64,x86_64-m32,i686}-fedora15-linux-gnu.


Thanks,
Jan


gdb/
2011-03-21  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* dwarf2expr.c (execute_stack_op): Handle DW_OP_GNU_entry_value.  New
	label abort_expression.
	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Handle
	DWARF_VALUE_OPTIMIZED_OUT.

gdb/testsuite/
2011-03-21  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.dwarf2/dw2-entry-value-main.c: New file.
	* gdb.dwarf2/dw2-entry-value.S: New file.
	* gdb.dwarf2/dw2-entry-value.exp: New file.

--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -904,6 +904,13 @@ execute_stack_op (struct dwarf_expr_context *ctx,
 	  op_ptr += 4;
 	  ctx->dwarf_call (ctx, result);
 	  goto no_push;
+	
+	case DW_OP_GNU_entry_value:
+	  /* This operation is not yet supported by GDB.  */
+	  ctx->location = DWARF_VALUE_OPTIMIZED_OUT;
+	  ctx->stack_len = 0;
+	  ctx->num_pieces = 0;
+	  goto abort_expression;
 
 	default:
 	  error (_("Unhandled dwarf expression opcode 0x%x"), op);
@@ -921,6 +928,7 @@ execute_stack_op (struct dwarf_expr_context *ctx,
   if (ctx->location == DWARF_VALUE_IMPLICIT_POINTER)
     add_piece (ctx, 8 * ctx->addr_size, 0);
 
+abort_expression:
   ctx->recursion_depth--;
   gdb_assert (ctx->recursion_depth >= 0);
 #undef sign_ext
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -1220,12 +1220,17 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	  }
 	  break;
 
+	case DWARF_VALUE_OPTIMIZED_OUT:
+	  retval = allocate_value (type);
+	  VALUE_LVAL (retval) = not_lval;
+	  set_value_optimized_out (retval, 1);
+	  break;
+
 	  /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
 	     operation by execute_stack_op.  */
 	case DWARF_VALUE_IMPLICIT_POINTER:
 	  /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
 	     it can only be encountered when making a piece.  */
-	case DWARF_VALUE_OPTIMIZED_OUT:
 	default:
 	  internal_error (__FILE__, __LINE__, _("invalid location type"));
 	}
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-entry-value-main.c
@@ -0,0 +1,37 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2011 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+asm (".globl f_start");
+asm ("f_start:");
+
+volatile int v;
+
+void
+f (int x)
+{
+  v++;
+}
+
+asm (".globl f_end");
+asm ("f_end:");
+
+int
+main (void)
+{
+  f (1);
+  return 0;
+}
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-entry-value.S
@@ -0,0 +1,104 @@
+/* Copyright 2011 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+	.section	.debug_info
+debug_start:
+	.long	debug_end - 1f	/* Length of Compilation Unit Info */
+1:
+	.2byte	0x3	/* DWARF version number */
+	.long	.Ldebug_abbrev0	/* Offset Into Abbrev. Section */
+	.byte	0x4	/* Pointer Size (in bytes) */
+	.uleb128 0x1	/* (DIE (0xb) DW_TAG_compile_unit) */
+	.ascii "GNU C 4.4.3\0"	/* DW_AT_producer */
+	.byte	0x1	/* DW_AT_language */
+	.ascii "1.c\0"	/* DW_AT_name */
+	.uleb128 0x4	/* (DIE (0x3c) DW_TAG_subprogram) */
+	.ascii "f\0"	/* DW_AT_name */
+	.long	f_start	/* DW_AT_low_pc */
+	.long	f_end	/* DW_AT_high_pc */
+	.byte	0x1	/* DW_AT_prototyped */
+	.uleb128 0x5	/* (DIE (0x42) DW_TAG_formal_parameter) */
+	.ascii	"param\0"		/* DW_AT_name */
+	.long	type - debug_start	/* DW_AT_type */
+	.long	loclist	/* DW_AT_location */
+	.byte	0x0	/* end of children of DIE 0x3c */
+type:
+	.uleb128	3			/* Abbrev: DW_TAG_base_type */
+	.ascii		"int\0"			/* DW_AT_name */
+	.byte		4			/* DW_AT_byte_size */
+	.byte		5			/* DW_AT_encoding */
+
+	.byte	0x0	/* end of children of DIE 0xb */
+debug_end:
+
+	.section	.debug_loc
+loclist:
+	.long	f_start, f_end
+	.2byte	2f-1f
+1:	.byte	0xf3	/* DW_OP_GNU_entry_value */
+	.uleb128  2f-3f
+3:	.byte	0x50	/* DW_OP_reg0 */
+2:
+	.long	0, 0
+
+	.section	.debug_abbrev
+.Ldebug_abbrev0:
+	.uleb128 0x1	/* (abbrev code) */
+	.uleb128 0x11	/* (TAG: DW_TAG_compile_unit) */
+	.byte	0x1	/* DW_children_yes */
+	.uleb128 0x25	/* (DW_AT_producer) */
+	.uleb128 0x8	/* (DW_FORM_string) */
+	.uleb128 0x13	/* (DW_AT_language) */
+	.uleb128 0xb	/* (DW_FORM_data1) */
+	.uleb128 0x3	/* (DW_AT_name) */
+	.uleb128 0x8	/* (DW_FORM_string) */
+	.byte	0x0
+	.byte	0x0
+	.uleb128	3			/* Abbrev code */
+	.uleb128	0x24			/* DW_TAG_base_type */
+	.byte		0			/* has_children */
+	.uleb128	0x3			/* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128	0xb			/* DW_AT_byte_size */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.uleb128	0x3e			/* DW_AT_encoding */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+	.uleb128 0x4	/* (abbrev code) */
+	.uleb128 0x2e	/* (TAG: DW_TAG_subprogram) */
+	.byte	0x1	/* DW_children_yes */
+	.uleb128 0x3	/* (DW_AT_name) */
+	.uleb128 0x8	/* (DW_FORM_string) */
+	.uleb128 0x11	/* (DW_AT_low_pc) */
+	.uleb128 0x1	/* (DW_FORM_addr) */
+	.uleb128 0x12	/* (DW_AT_high_pc) */
+	.uleb128 0x1	/* (DW_FORM_addr) */
+	.uleb128 0x27	/* (DW_AT_prototyped) */
+	.uleb128 0xc	/* (DW_FORM_flag) */
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x5	/* (abbrev code) */
+	.uleb128 0x5	/* (TAG: DW_TAG_formal_parameter) */
+	.byte	0x0	/* DW_children_no */
+	.uleb128	0x3			/* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128 0x49	/* (DW_AT_type) */
+	.uleb128 0x13	/* (DW_FORM_ref4) */
+	.uleb128 0x02	/* (DW_AT_location) */
+	.uleb128 0x06	/* (DW_FORM_data4) */
+	.byte	0x0
+	.byte	0x0
+	.byte	0x0
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-entry-value.exp
@@ -0,0 +1,32 @@
+# Copyright 2011 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+    return 0  
+}
+
+if { [prepare_for_testing dw2-entry-value.exp "dw2-entry-value" {dw2-entry-value-main.c dw2-entry-value.S} {nodebug}] } {
+    return -1
+}
+
+if ![runto f] {
+    return -1
+}
+
+# FAIL was printing:
+# param=Unhandled dwarf expression opcode 0xf3
+gdb_test "frame" "param=<optimized out>.*" "<optimized out> is printed"