[patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Jan Kratochvil]

Hi,

this is an improved patch of a former:
	[patch] workaround gcc46: prologue skip skips too far (PR 12435)
	http://sourceware.org/ml/gdb-patches/2011-03/msg01108.html
	cancel/FYI: Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435)
	http://sourceware.org/ml/gdb-patches/2011-03/msg01123.html

For example `break error' does not work for debugging GDB with gcc-4.6.x.

As gcc-4.6.0 and now even 4.6.1 still has this bug and I have seen a user(s?)
on non-Fedora platform asking about this bug and as there may be enough
binaries out there (although it affects only -O0 -g compilation) coded it
properly I have coded the workaround properly this time.

It does not solve overlays well, but the code just does not work for overlays,
it has no other negative effect.

I will update the code after FSF gcc gets fixed to minimize the workaround.

No regressions on {x86_64,x86_64-m32,i686}-fedora16pre-linux-gnu.

I would welcome a comment whether it is suitable for FSF GDB.


Thanks,
Jan


gdb/
2011-07-22  Jan Kratochvil  <jan.kratochvil@redhat.com>

	PR breakpoints/12435
	* amd64-tdep.c (amd64_skip_prologue): New variables start_pc_sal,
	next_sal, buf, offset and xmmreg.  Advance PC if it sees the PR.
	* dwarf2read.c (process_full_comp_unit): Initialize
	amd64_prologue_line_bug.
	* symtab.h (struct symtab): New field amd64_prologue_line_bug.

gdb/testsuite/
2011-07-22  Jan Kratochvil  <jan.kratochvil@redhat.com>

	PR breakpoints/12435
	* gdb.arch/amd64-prologue-xmm.c: New file.
	* gdb.arch/amd64-prologue-xmm.exp: New file.
	* gdb.arch/amd64-prologue-xmm.s: New file.

--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -1902,6 +1902,9 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
 {
   struct amd64_frame_cache cache;
   CORE_ADDR pc;
+  struct symtab_and_line start_pc_sal, next_sal;
+  gdb_byte buf[4 + 8 * 7];
+  int offset, xmmreg;
 
   amd64_init_frame_cache (&cache);
   pc = amd64_analyze_prologue (gdbarch, start_pc, 0xffffffffffffffffLL,
@@ -1909,7 +1912,71 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
   if (cache.frameless_p)
     return start_pc;
 
-  return pc;
+  /* GCC PR debug/48827 produced false prologue end:
+     84 c0                test   %al,%al
+     74 23                je     after
+     <-- here is 0 lines advance - the false prologue end marker.
+     0f 29 85 70 ff ff ff movaps %xmm0,-0x90(%rbp)
+     0f 29 4d 80          movaps %xmm1,-0x80(%rbp)
+     0f 29 55 90          movaps %xmm2,-0x70(%rbp)
+     0f 29 5d a0          movaps %xmm3,-0x60(%rbp)
+     0f 29 65 b0          movaps %xmm4,-0x50(%rbp)
+     0f 29 6d c0          movaps %xmm5,-0x40(%rbp)
+     0f 29 75 d0          movaps %xmm6,-0x30(%rbp)
+     0f 29 7d e0          movaps %xmm7,-0x20(%rbp)
+     after:  */
+
+  if (pc == start_pc)
+    return pc;
+
+  start_pc_sal = find_pc_sect_line (start_pc, NULL, 0);
+  if (start_pc_sal.symtab == NULL
+      || !start_pc_sal.symtab->amd64_prologue_line_bug
+      || start_pc_sal.pc != start_pc || pc >= start_pc_sal.end)
+    return pc;
+
+  next_sal = find_pc_sect_line (start_pc_sal.end, NULL, 0);
+  if (next_sal.line != start_pc_sal.line)
+    return pc;
+
+  /* START_PC can be from overlayed memory, ignored here.  */
+  if (target_read_memory (next_sal.pc - 4, buf, sizeof (buf)) != 0)
+    return pc;
+
+  /* test %al,%al */
+  if (buf[0] != 0x84 || buf[1] != 0xc0)
+    return pc;
+  /* je AFTER */
+  if (buf[2] != 0x74)
+    return pc;
+
+  offset = 4;
+  for (xmmreg = 0; xmmreg < 8; xmmreg++)
+    {
+      /* movaps %xmmreg?,-0x??(%rbp) */
+      if (buf[offset] != 0x0f || buf[offset + 1] != 0x29
+          || (buf[offset + 2] & 0b00111111) != (xmmreg << 3 | 0b101))
+	return pc;
+
+      if ((buf[offset + 2] & 0b11000000) == 0b01000000)
+	{
+	  /* 8-bit displacement.  */
+	  offset += 4;
+	}
+      else if ((buf[offset + 2] & 0b11000000) == 0b10000000)
+	{
+	  /* 32-bit displacement.  */
+	  offset += 7;
+	}
+      else
+	return pc;
+    }
+
+  /* je AFTER */
+  if (offset - 4 != buf[3])
+    return pc;
+
+  return next_sal.end;
 }
 \f
 
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -4818,6 +4818,9 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu)
 
       if (gcc_4_minor >= 5)
 	symtab->epilogue_unwind_valid = 1;
+
+      if (gcc_4_minor >= 6)
+	symtab->amd64_prologue_line_bug = 1;
     }
 
   if (dwarf2_per_objfile->using_index)
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -784,6 +784,11 @@ struct symtab
 
   unsigned int epilogue_unwind_valid : 1;
 
+  /* At least GCC 4.6.0 and 4.6.1 can produce invalid false prologue and marker
+     on amd64.  This flag is set independently of the symtab arch.  */
+
+  unsigned amd64_prologue_line_bug : 1;
+
   /* The macro table for this symtab.  Like the blockvector, this
      may be shared between different symtabs --- and normally is for
      all the symtabs in a given compilation unit.  */
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-prologue-xmm.c
@@ -0,0 +1,38 @@
+/* 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/>.  */
+
+static volatile int v, fail;
+
+static void
+func (int i, ...)
+{
+  v = i;
+}
+
+static void
+marker (void)
+{
+}
+
+int
+main (void)
+{
+  func (1);
+  fail = 1;
+  marker ();
+  return 0;
+}
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-prologue-xmm.exp
@@ -0,0 +1,46 @@
+# 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/>.
+
+# Test GCC PR debug/48827 workaround in GDB.
+
+set testfile "amd64-prologue-xmm"
+set srcfile ${testfile}.s
+set csrcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}.x
+set opts {}
+
+if [info exists COMPILE] {
+    # make check RUNTESTFLAGS='gdb.arch/amd64-prologue-xmm.exp COMPILE=1'
+    set srcfile ${csrcfile}
+    lappend opts debug optimize=-O0
+} elseif { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
+    verbose "Skipping amd64-prologue-xmm test."
+    return 0
+}
+
+if {[prepare_for_testing ${testfile}.exp ${testfile} $srcfile $opts]} {
+    return -1
+}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint "func"
+gdb_breakpoint "marker"
+
+gdb_continue_to_breakpoint "func"
+
+gdb_test "p fail" " = 0" "stopped at func"
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-prologue-xmm.s
@@ -0,0 +1,400 @@
+/* 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/>.  */
+      	
+/* This file is compiled from gdb.arch/amd64-prologue-xmm.c
+   using -g -dA -S.  */
+
+	.file	"amd64-prologue-xmm.c"
+	.text
+.Ltext0:
+	.local	v
+	.comm	v,4,4
+	.local	fail
+	.comm	fail,4,4
+	.type	func, @function
+func:
+.LFB0:
+	.file 1 "gdb.arch/amd64-prologue-xmm.c"
+	# gdb.arch/amd64-prologue-xmm.c:22
+	.loc 1 22 0
+	.cfi_startproc
+	# basic block 2
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	subq	$72, %rsp
+	movq	%rsi, -168(%rbp)
+	movq	%rdx, -160(%rbp)
+	movq	%rcx, -152(%rbp)
+	movq	%r8, -144(%rbp)
+	movq	%r9, -136(%rbp)
+	testb	%al, %al
+	je	.L2
+	# basic block 3
+	# gdb.arch/amd64-prologue-xmm.c:22
+	.loc 1 22 0
+	movaps	%xmm0, -128(%rbp)
+	movaps	%xmm1, -112(%rbp)
+	movaps	%xmm2, -96(%rbp)
+	movaps	%xmm3, -80(%rbp)
+	movaps	%xmm4, -64(%rbp)
+	movaps	%xmm5, -48(%rbp)
+	movaps	%xmm6, -32(%rbp)
+	movaps	%xmm7, -16(%rbp)
+.L2:
+	# basic block 4
+	movl	%edi, -180(%rbp)
+	# gdb.arch/amd64-prologue-xmm.c:23
+	.loc 1 23 0
+	movl	-180(%rbp), %eax
+	movl	%eax, v(%rip)
+	# gdb.arch/amd64-prologue-xmm.c:24
+	.loc 1 24 0
+	leave
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE0:
+	.size	func, .-func
+	.type	marker, @function
+marker:
+.LFB1:
+	# gdb.arch/amd64-prologue-xmm.c:28
+	.loc 1 28 0
+	.cfi_startproc
+	# basic block 2
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	# gdb.arch/amd64-prologue-xmm.c:29
+	.loc 1 29 0
+	popq	%rbp
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE1:
+	.size	marker, .-marker
+	.globl	main
+	.type	main, @function
+main:
+.LFB2:
+	# gdb.arch/amd64-prologue-xmm.c:33
+	.loc 1 33 0
+	.cfi_startproc
+	# basic block 2
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	# gdb.arch/amd64-prologue-xmm.c:34
+	.loc 1 34 0
+	movl	$1, %edi
+	movl	$0, %eax
+	call	func
+	# gdb.arch/amd64-prologue-xmm.c:35
+	.loc 1 35 0
+	movl	$1, fail(%rip)
+	# gdb.arch/amd64-prologue-xmm.c:36
+	.loc 1 36 0
+	call	marker
+	# gdb.arch/amd64-prologue-xmm.c:37
+	.loc 1 37 0
+	movl	$0, %eax
+	# gdb.arch/amd64-prologue-xmm.c:38
+	.loc 1 38 0
+	popq	%rbp
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE2:
+	.size	main, .-main
+.Letext0:
+	.section	.debug_info,"",@progbits
+.Ldebug_info0:
+	.long	0xc0	# Length of Compilation Unit Info
+	.value	0x4	# DWARF version number
+	.long	.Ldebug_abbrev0	# Offset Into Abbrev. Section
+	.byte	0x8	# Pointer Size (in bytes)
+	.uleb128 0x1	# (DIE (0xb) DW_TAG_compile_unit)
+	.long	.LASF1	# DW_AT_producer: "GNU C 4.6.1 20110715 (Red Hat 4.6.1-3)"
+	.byte	0x1	# DW_AT_language
+	.long	.LASF2	# DW_AT_name: "gdb.arch/amd64-prologue-xmm.c"
+	.long	.LASF3	# DW_AT_comp_dir: ""
+	.quad	.Ltext0	# DW_AT_low_pc
+	.quad	.Letext0	# DW_AT_high_pc
+	.long	.Ldebug_line0	# DW_AT_stmt_list
+	.uleb128 0x2	# (DIE (0x2d) DW_TAG_subprogram)
+	.long	.LASF4	# DW_AT_name: "func"
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x15	# DW_AT_decl_line
+			# DW_AT_prototyped
+	.quad	.LFB0	# DW_AT_low_pc
+	.quad	.LFE0	# DW_AT_high_pc
+	.uleb128 0x1	# DW_AT_frame_base
+	.byte	0x9c	# DW_OP_call_frame_cfa
+			# DW_AT_GNU_all_call_sites
+	.long	0x59	# DW_AT_sibling
+	.uleb128 0x3	# (DIE (0x4a) DW_TAG_formal_parameter)
+	.ascii "i\0"	# DW_AT_name
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x15	# DW_AT_decl_line
+	.long	0x59	# DW_AT_type
+	.uleb128 0x3	# DW_AT_location
+	.byte	0x91	# DW_OP_fbreg
+	.sleb128 -196
+	.uleb128 0x4	# (DIE (0x57) DW_TAG_unspecified_parameters)
+	.byte	0	# end of children of DIE 0x2d
+	.uleb128 0x5	# (DIE (0x59) DW_TAG_base_type)
+	.byte	0x4	# DW_AT_byte_size
+	.byte	0x5	# DW_AT_encoding
+	.ascii "int\0"	# DW_AT_name
+	.uleb128 0x6	# (DIE (0x60) DW_TAG_subprogram)
+	.long	.LASF5	# DW_AT_name: "marker"
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x1b	# DW_AT_decl_line
+			# DW_AT_prototyped
+	.quad	.LFB1	# DW_AT_low_pc
+	.quad	.LFE1	# DW_AT_high_pc
+	.uleb128 0x1	# DW_AT_frame_base
+	.byte	0x9c	# DW_OP_call_frame_cfa
+			# DW_AT_GNU_all_call_sites
+	.uleb128 0x7	# (DIE (0x79) DW_TAG_subprogram)
+			# DW_AT_external
+	.long	.LASF6	# DW_AT_name: "main"
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x20	# DW_AT_decl_line
+			# DW_AT_prototyped
+	.long	0x59	# DW_AT_type
+	.quad	.LFB2	# DW_AT_low_pc
+	.quad	.LFE2	# DW_AT_high_pc
+	.uleb128 0x1	# DW_AT_frame_base
+	.byte	0x9c	# DW_OP_call_frame_cfa
+			# DW_AT_GNU_all_tail_call_sites
+	.uleb128 0x8	# (DIE (0x96) DW_TAG_variable)
+	.ascii "v\0"	# DW_AT_name
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x12	# DW_AT_decl_line
+	.long	0xa9	# DW_AT_type
+	.uleb128 0x9	# DW_AT_location
+	.byte	0x3	# DW_OP_addr
+	.quad	v
+	.uleb128 0x9	# (DIE (0xa9) DW_TAG_volatile_type)
+	.long	0x59	# DW_AT_type
+	.uleb128 0xa	# (DIE (0xae) DW_TAG_variable)
+	.long	.LASF0	# DW_AT_name: "fail"
+	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-prologue-xmm.c)
+	.byte	0x12	# DW_AT_decl_line
+	.long	0xa9	# DW_AT_type
+	.uleb128 0x9	# DW_AT_location
+	.byte	0x3	# DW_OP_addr
+	.quad	fail
+	.byte	0	# end of children of DIE 0xb
+	.section	.debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+	.uleb128 0x1	# (abbrev code)
+	.uleb128 0x11	# (TAG: DW_TAG_compile_unit)
+	.byte	0x1	# DW_children_yes
+	.uleb128 0x25	# (DW_AT_producer)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x13	# (DW_AT_language)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x1b	# (DW_AT_comp_dir)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x11	# (DW_AT_low_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x12	# (DW_AT_high_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x10	# (DW_AT_stmt_list)
+	.uleb128 0x17	# (DW_FORM_sec_offset)
+	.byte	0
+	.byte	0
+	.uleb128 0x2	# (abbrev code)
+	.uleb128 0x2e	# (TAG: DW_TAG_subprogram)
+	.byte	0x1	# DW_children_yes
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x27	# (DW_AT_prototyped)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.uleb128 0x11	# (DW_AT_low_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x12	# (DW_AT_high_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x40	# (DW_AT_frame_base)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.uleb128 0x2117	# (DW_AT_GNU_all_call_sites)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.uleb128 0x1	# (DW_AT_sibling)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.byte	0
+	.byte	0
+	.uleb128 0x3	# (abbrev code)
+	.uleb128 0x5	# (TAG: DW_TAG_formal_parameter)
+	.byte	0	# DW_children_no
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0x8	# (DW_FORM_string)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x49	# (DW_AT_type)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.uleb128 0x2	# (DW_AT_location)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.byte	0
+	.byte	0
+	.uleb128 0x4	# (abbrev code)
+	.uleb128 0x18	# (TAG: DW_TAG_unspecified_parameters)
+	.byte	0	# DW_children_no
+	.byte	0
+	.byte	0
+	.uleb128 0x5	# (abbrev code)
+	.uleb128 0x24	# (TAG: DW_TAG_base_type)
+	.byte	0	# DW_children_no
+	.uleb128 0xb	# (DW_AT_byte_size)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3e	# (DW_AT_encoding)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0x8	# (DW_FORM_string)
+	.byte	0
+	.byte	0
+	.uleb128 0x6	# (abbrev code)
+	.uleb128 0x2e	# (TAG: DW_TAG_subprogram)
+	.byte	0	# DW_children_no
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x27	# (DW_AT_prototyped)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.uleb128 0x11	# (DW_AT_low_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x12	# (DW_AT_high_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x40	# (DW_AT_frame_base)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.uleb128 0x2117	# (DW_AT_GNU_all_call_sites)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.byte	0
+	.byte	0
+	.uleb128 0x7	# (abbrev code)
+	.uleb128 0x2e	# (TAG: DW_TAG_subprogram)
+	.byte	0	# DW_children_no
+	.uleb128 0x3f	# (DW_AT_external)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x27	# (DW_AT_prototyped)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.uleb128 0x49	# (DW_AT_type)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.uleb128 0x11	# (DW_AT_low_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x12	# (DW_AT_high_pc)
+	.uleb128 0x1	# (DW_FORM_addr)
+	.uleb128 0x40	# (DW_AT_frame_base)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.uleb128 0x2116	# (DW_AT_GNU_all_tail_call_sites)
+	.uleb128 0x19	# (DW_FORM_flag_present)
+	.byte	0
+	.byte	0
+	.uleb128 0x8	# (abbrev code)
+	.uleb128 0x34	# (TAG: DW_TAG_variable)
+	.byte	0	# DW_children_no
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0x8	# (DW_FORM_string)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x49	# (DW_AT_type)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.uleb128 0x2	# (DW_AT_location)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.byte	0
+	.byte	0
+	.uleb128 0x9	# (abbrev code)
+	.uleb128 0x35	# (TAG: DW_TAG_volatile_type)
+	.byte	0	# DW_children_no
+	.uleb128 0x49	# (DW_AT_type)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.byte	0
+	.byte	0
+	.uleb128 0xa	# (abbrev code)
+	.uleb128 0x34	# (TAG: DW_TAG_variable)
+	.byte	0	# DW_children_no
+	.uleb128 0x3	# (DW_AT_name)
+	.uleb128 0xe	# (DW_FORM_strp)
+	.uleb128 0x3a	# (DW_AT_decl_file)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x3b	# (DW_AT_decl_line)
+	.uleb128 0xb	# (DW_FORM_data1)
+	.uleb128 0x49	# (DW_AT_type)
+	.uleb128 0x13	# (DW_FORM_ref4)
+	.uleb128 0x2	# (DW_AT_location)
+	.uleb128 0x18	# (DW_FORM_exprloc)
+	.byte	0
+	.byte	0
+	.byte	0
+	.section	.debug_aranges,"",@progbits
+	.long	0x2c	# Length of Address Ranges Info
+	.value	0x2	# DWARF Version
+	.long	.Ldebug_info0	# Offset of Compilation Unit Info
+	.byte	0x8	# Size of Address
+	.byte	0	# Size of Segment Descriptor
+	.value	0	# Pad to 16 byte boundary
+	.value	0
+	.quad	.Ltext0	# Address
+	.quad	.Letext0-.Ltext0	# Length
+	.quad	0
+	.quad	0
+	.section	.debug_line,"",@progbits
+.Ldebug_line0:
+	.section	.debug_str,"MS",@progbits,1
+.LASF3:
+	.string	""
+.LASF0:
+	.string	"fail"
+.LASF4:
+	.string	"func"
+.LASF1:
+	.string	"GNU C 4.6.1 20110715 (Red Hat 4.6.1-3)"
+.LASF2:
+	.string	"gdb.arch/amd64-prologue-xmm.c"
+.LASF5:
+	.string	"marker"
+.LASF6:
+	.string	"main"
+	.ident	"GCC: (GNU) 4.6.1 20110715 (Red Hat 4.6.1-3)"
+	.section	.note.GNU-stack,"",@progbits

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Mark Kettenis]

> Date: Fri, 22 Jul 2011 23:58:21 +0200
> From: Jan Kratochvil <jan.kratochvil@redhat.com>
> 
> Hi,
> 
> this is an improved patch of a former:
> 	[patch] workaround gcc46: prologue skip skips too far (PR 12435)
> 	http://sourceware.org/ml/gdb-patches/2011-03/msg01108.html
> 	cancel/FYI: Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435)
> 	http://sourceware.org/ml/gdb-patches/2011-03/msg01123.html
> 
> For example `break error' does not work for debugging GDB with gcc-4.6.x.
> 
> As gcc-4.6.0 and now even 4.6.1 still has this bug and I have seen a user(s?)
> on non-Fedora platform asking about this bug and as there may be enough
> binaries out there (although it affects only -O0 -g compilation) coded it
> properly I have coded the workaround properly this time.
> 
> It does not solve overlays well, but the code just does not work for
> overlays, it has no other negative effect.

Sorry, but what do you mean with "overlays" here?

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Jan Kratochvil]

On Sun, 24 Jul 2011 20:03:53 +0200, Mark Kettenis wrote:
> > It does not solve overlays well, but the code just does not work for
> > overlays, it has no other negative effect.
> 
> Sorry, but what do you mean with "overlays" here?

See skip_prologue_sal:
      /* If the function is in an unmapped overlay, use its unmapped LMA address,
         so that gdbarch_skip_prologue has something unique to work on.  */
      if (section_is_overlay (section) && !section_is_mapped (section))
        pc = overlay_unmapped_address (pc, section);

      /* Skip "first line" of function (which is actually its prologue).  */
      pc += gdbarch_deprecated_function_start_offset (gdbarch);
      if (skip)
        pc = gdbarch_skip_prologue (gdbarch, pc);

      /* For overlays, map pc back into its mapped VMA range.  */
      pc = overlay_mapped_address (pc, section);

So in gdbarch_skip_prologue the PC is LMA, I do not know how
gdbarch_skip_prologue could read the bytes at PC (without introducing new
parameter(s) to gdbarch_skip_prologue).


Thanks,
Jan

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Jan Kratochvil]

On Fri, 22 Jul 2011 23:58:21 +0200, Jan Kratochvil wrote:
> gdb/
> 2011-07-22  Jan Kratochvil  <jan.kratochvil@redhat.com>
> 
> 	PR breakpoints/12435
> 	* amd64-tdep.c (amd64_skip_prologue): New variables start_pc_sal,
> 	next_sal, buf, offset and xmmreg.  Advance PC if it sees the PR.
> 	* dwarf2read.c (process_full_comp_unit): Initialize
> 	amd64_prologue_line_bug.
> 	* symtab.h (struct symtab): New field amd64_prologue_line_bug.
> 
> gdb/testsuite/
> 2011-07-22  Jan Kratochvil  <jan.kratochvil@redhat.com>
> 
> 	PR breakpoints/12435
> 	* gdb.arch/amd64-prologue-xmm.c: New file.
> 	* gdb.arch/amd64-prologue-xmm.exp: New file.
> 	* gdb.arch/amd64-prologue-xmm.s: New file.

Checked in:
	http://sourceware.org/ml/gdb-cvs/2011-09/msg00046.html


Thanks,
Jan

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Doug Evans]

On Fri, Jul 22, 2011 at 2:58 PM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> Hi,
>
> this is an improved patch of a former:
>        [patch] workaround gcc46: prologue skip skips too far (PR 12435)
>        http://sourceware.org/ml/gdb-patches/2011-03/msg01108.html
>        cancel/FYI: Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435)
>        http://sourceware.org/ml/gdb-patches/2011-03/msg01123.html
>
> [...]
>
> I will update the code after FSF gcc gets fixed to minimize the workaround.

I realize this is checked in, but a couple of comments for maybe the
next patch for this.

> [...]
>
> --- a/gdb/amd64-tdep.c
> +++ b/gdb/amd64-tdep.c
> @@ -1902,6 +1902,9 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
>  {
>   struct amd64_frame_cache cache;
>   CORE_ADDR pc;
> +  struct symtab_and_line start_pc_sal, next_sal;
> +  gdb_byte buf[4 + 8 * 7];
> +  int offset, xmmreg;
>
>   amd64_init_frame_cache (&cache);
>   pc = amd64_analyze_prologue (gdbarch, start_pc, 0xffffffffffffffffLL,
> @@ -1909,7 +1912,71 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
>   if (cache.frameless_p)
>     return start_pc;
>
> -  return pc;
> +  /* GCC PR debug/48827 produced false prologue end:
> +     84 c0                test   %al,%al
> +     74 23                je     after
> +     <-- here is 0 lines advance - the false prologue end marker.
> +     0f 29 85 70 ff ff ff movaps %xmm0,-0x90(%rbp)
> +     0f 29 4d 80          movaps %xmm1,-0x80(%rbp)
> +     0f 29 55 90          movaps %xmm2,-0x70(%rbp)
> +     0f 29 5d a0          movaps %xmm3,-0x60(%rbp)
> +     0f 29 65 b0          movaps %xmm4,-0x50(%rbp)
> +     0f 29 6d c0          movaps %xmm5,-0x40(%rbp)
> +     0f 29 75 d0          movaps %xmm6,-0x30(%rbp)
> +     0f 29 7d e0          movaps %xmm7,-0x20(%rbp)
> +     after:  */
> +
> +  if (pc == start_pc)
> +    return pc;
> +
> +  start_pc_sal = find_pc_sect_line (start_pc, NULL, 0);
> +  if (start_pc_sal.symtab == NULL
> +      || !start_pc_sal.symtab->amd64_prologue_line_bug
> +      || start_pc_sal.pc != start_pc || pc >= start_pc_sal.end)
> +    return pc;
> +
> +  next_sal = find_pc_sect_line (start_pc_sal.end, NULL, 0);
> +  if (next_sal.line != start_pc_sal.line)
> +    return pc;
> +
> +  /* START_PC can be from overlayed memory, ignored here.  */
> +  if (target_read_memory (next_sal.pc - 4, buf, sizeof (buf)) != 0)
> +    return pc;
> +
> +  /* test %al,%al */
> +  if (buf[0] != 0x84 || buf[1] != 0xc0)
> +    return pc;
> +  /* je AFTER */
> +  if (buf[2] != 0x74)
> +    return pc;
> +
> +  offset = 4;
> +  for (xmmreg = 0; xmmreg < 8; xmmreg++)
> +    {
> +      /* movaps %xmmreg?,-0x??(%rbp) */
> +      if (buf[offset] != 0x0f || buf[offset + 1] != 0x29
> +          || (buf[offset + 2] & 0b00111111) != (xmmreg << 3 | 0b101))
> +       return pc;
> +
> +      if ((buf[offset + 2] & 0b11000000) == 0b01000000)
> +       {
> +         /* 8-bit displacement.  */
> +         offset += 4;
> +       }
> +      else if ((buf[offset + 2] & 0b11000000) == 0b10000000)
> +       {
> +         /* 32-bit displacement.  */
> +         offset += 7;
> +       }
> +      else
> +       return pc;
> +    }
> +
> +  /* je AFTER */
> +  if (offset - 4 != buf[3])
> +    return pc;
> +
> +  return next_sal.end;
>  }

These kinds of functions tend to grow and grow and become hard to maintain.
IWBN if all this new code is about a specific issue then tuck it away
in its own function.
[Or at least document both the start and end of it.]

> [...]
>
> --- a/gdb/symtab.h
> +++ b/gdb/symtab.h
> @@ -784,6 +784,11 @@ struct symtab
>
>   unsigned int epilogue_unwind_valid : 1;
>
> +  /* At least GCC 4.6.0 and 4.6.1 can produce invalid false prologue and marker
> +     on amd64.  This flag is set independently of the symtab arch.  */
> +
> +  unsigned amd64_prologue_line_bug : 1;
> +
>   /* The macro table for this symtab.  Like the blockvector, this
>      may be shared between different symtabs --- and normally is for
>      all the symtabs in a given compilation unit.  */

I can hear the screams of pushback if a random net person wanted to
check in anything architecture specific to the architecture
independent part of gdb. :-)

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Jan Kratochvil]

On Thu, 08 Sep 2011 19:15:59 +0200, Doug Evans wrote:
> These kinds of functions tend to grow and grow and become hard to maintain.
> IWBN if all this new code is about a specific issue then tuck it away
> in its own function.

I agree it is a good improvement.


> > +  /* At least GCC 4.6.0 and 4.6.1 can produce invalid false prologue and marker
> > +     on amd64.  This flag is set independently of the symtab arch.  */
> > +
> > +  unsigned amd64_prologue_line_bug : 1;
> 
> I can hear the screams of pushback if a random net person wanted to
> check in anything architecture specific to the architecture
> independent part of gdb. :-)

That is a good comment.  There is also symtab->producer, not just cu->producer
so it is not needed at all.

I will check it in.


Thanks,
Jan


gdb/
2011-09-08  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Code cleanup.
	* amd64-tdep.c (amd64_skip_prologue): Move the XMM code to ...
	(amd64_skip_xmm_prologue): ... this new function.  Describe its
	parameters.  No longer use amd64_prologue_line_bug.
	* defs.h (producer_is_gcc_ge_4): New declaration.
	* dwarf2read.c (producer_is_gcc_ge_4): Move to utils.c.
	(process_full_comp_unit): Update its caller.  Remove
	amd64_prologue_line_bug initialization.
	* symtab.h (struct symtab): Remove field amd64_prologue_line_bug.
	* utils.c (producer_is_gcc_ge_4): Moved here from dwarf2read.c.

--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -1910,43 +1910,37 @@ amd64_analyze_prologue (struct gdbarch *gdbarch,
   return pc;
 }
 
-/* Return PC of first real instruction.  */
+/* Work around false termination of prologue - GCC PR debug/48827.
+
+   START_PC is the first instruction of a function, PC is its minimal already
+   determined advanced address.  Function returns PC if it has nothing to do.
+
+   84 c0                test   %al,%al
+   74 23                je     after
+   <-- here is 0 lines advance - the false prologue end marker.
+   0f 29 85 70 ff ff ff movaps %xmm0,-0x90(%rbp)
+   0f 29 4d 80          movaps %xmm1,-0x80(%rbp)
+   0f 29 55 90          movaps %xmm2,-0x70(%rbp)
+   0f 29 5d a0          movaps %xmm3,-0x60(%rbp)
+   0f 29 65 b0          movaps %xmm4,-0x50(%rbp)
+   0f 29 6d c0          movaps %xmm5,-0x40(%rbp)
+   0f 29 75 d0          movaps %xmm6,-0x30(%rbp)
+   0f 29 7d e0          movaps %xmm7,-0x20(%rbp)
+   after:  */
 
 static CORE_ADDR
-amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
+amd64_skip_xmm_prologue (CORE_ADDR pc, CORE_ADDR start_pc)
 {
-  struct amd64_frame_cache cache;
-  CORE_ADDR pc;
   struct symtab_and_line start_pc_sal, next_sal;
   gdb_byte buf[4 + 8 * 7];
   int offset, xmmreg;
 
-  amd64_init_frame_cache (&cache);
-  pc = amd64_analyze_prologue (gdbarch, start_pc, 0xffffffffffffffffLL,
-			       &cache);
-  if (cache.frameless_p)
-    return start_pc;
-
-  /* GCC PR debug/48827 produced false prologue end:
-     84 c0                test   %al,%al
-     74 23                je     after
-     <-- here is 0 lines advance - the false prologue end marker.
-     0f 29 85 70 ff ff ff movaps %xmm0,-0x90(%rbp)
-     0f 29 4d 80          movaps %xmm1,-0x80(%rbp)
-     0f 29 55 90          movaps %xmm2,-0x70(%rbp)
-     0f 29 5d a0          movaps %xmm3,-0x60(%rbp)
-     0f 29 65 b0          movaps %xmm4,-0x50(%rbp)
-     0f 29 6d c0          movaps %xmm5,-0x40(%rbp)
-     0f 29 75 d0          movaps %xmm6,-0x30(%rbp)
-     0f 29 7d e0          movaps %xmm7,-0x20(%rbp)
-     after:  */
-
   if (pc == start_pc)
     return pc;
 
   start_pc_sal = find_pc_sect_line (start_pc, NULL, 0);
   if (start_pc_sal.symtab == NULL
-      || !start_pc_sal.symtab->amd64_prologue_line_bug
+      || producer_is_gcc_ge_4 (start_pc_sal.symtab->producer) < 6
       || start_pc_sal.pc != start_pc || pc >= start_pc_sal.end)
     return pc;
 
@@ -1993,6 +1987,23 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
 
   return next_sal.end;
 }
+
+/* Return PC of first real instruction.  */
+
+static CORE_ADDR
+amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
+{
+  struct amd64_frame_cache cache;
+  CORE_ADDR pc;
+
+  amd64_init_frame_cache (&cache);
+  pc = amd64_analyze_prologue (gdbarch, start_pc, 0xffffffffffffffffLL,
+			       &cache);
+  if (cache.frameless_p)
+    return start_pc;
+
+  return amd64_skip_xmm_prologue (pc, start_pc);
+}
 \f
 
 /* Normal frames.  */
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -431,6 +431,8 @@ extern int parse_pid_to_attach (char *args);
 
 extern struct cleanup *make_bpstat_clear_actions_cleanup (void);
 
+extern int producer_is_gcc_ge_4 (const char *producer);
+
 /* From demangle.c */
 
 extern void set_demangling_style (char *);
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -4723,50 +4723,6 @@ compute_delayed_physnames (struct dwarf2_cu *cu)
     }
 }
 
-/* Check for GCC >= 4.x.  Return minor version (x) of 4.x in such case.  If it
-   is not GCC or it is GCC older than 4.x return -1.  If it is GCC 5.x or
-   higher return INT_MAX.  */
-
-static int
-producer_is_gcc_ge_4 (struct dwarf2_cu *cu)
-{
-  const char *cs;
-  int major, minor;
-
-  if (cu->producer == NULL)
-    {
-      /* For unknown compilers expect their behavior is not compliant.  For GCC
-	 this case can also happen for -gdwarf-4 type units supported since
-	 gcc-4.5.  */
-
-      return -1;
-    }
-
-  /* Skip any identifier after "GNU " - such as "C++" or "Java".  */
-
-  if (strncmp (cu->producer, "GNU ", strlen ("GNU ")) != 0)
-    {
-      /* For non-GCC compilers expect their behavior is not compliant.  */
-
-      return -1;
-    }
-  cs = &cu->producer[strlen ("GNU ")];
-  while (*cs && !isdigit (*cs))
-    cs++;
-  if (sscanf (cs, "%d.%d", &major, &minor) != 2)
-    {
-      /* Not recognized as GCC.  */
-
-      return -1;
-    }
-
-  if (major < 4)
-    return -1;
-  if (major > 4)
-    return INT_MAX;
-  return minor;
-}
-
 /* Generate full symbol information for PST and CU, whose DIEs have
    already been loaded into memory.  */
 
@@ -4806,7 +4762,7 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu)
 
   if (symtab != NULL)
     {
-      int gcc_4_minor = producer_is_gcc_ge_4 (cu);
+      int gcc_4_minor = producer_is_gcc_ge_4 (cu->producer);
 
       /* Set symtab language to language from DW_AT_language.  If the
 	 compilation is from a C file generated by language preprocessors, do
@@ -4829,9 +4785,6 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu)
 
       if (gcc_4_minor >= 5)
 	symtab->epilogue_unwind_valid = 1;
-
-      if (gcc_4_minor >= 6)
-	symtab->amd64_prologue_line_bug = 1;
     }
 
   if (dwarf2_per_objfile->using_index)
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -784,11 +784,6 @@ struct symtab
 
   unsigned int epilogue_unwind_valid : 1;
 
-  /* At least GCC 4.6.0 and 4.6.1 can produce invalid false prologue and marker
-     on amd64.  This flag is set independently of the symtab arch.  */
-
-  unsigned amd64_prologue_line_bug : 1;
-
   /* The macro table for this symtab.  Like the blockvector, this
      may be shared between different symtabs --- and normally is for
      all the symtabs in a given compilation unit.  */
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -3691,6 +3691,50 @@ make_bpstat_clear_actions_cleanup (void)
   return make_cleanup (do_bpstat_clear_actions_cleanup, NULL);
 }
 
+/* Check for GCC >= 4.x according to the symtab->producer string.  Return minor
+   version (x) of 4.x in such case.  If it is not GCC or it is GCC older than
+   4.x return -1.  If it is GCC 5.x or higher return INT_MAX.  */
+
+int
+producer_is_gcc_ge_4 (const char *producer)
+{
+  const char *cs;
+  int major, minor;
+
+  if (producer == NULL)
+    {
+      /* For unknown compilers expect their behavior is not compliant.  For GCC
+	 this case can also happen for -gdwarf-4 type units supported since
+	 gcc-4.5.  */
+
+      return -1;
+    }
+
+  /* Skip any identifier after "GNU " - such as "C++" or "Java".  */
+
+  if (strncmp (producer, "GNU ", strlen ("GNU ")) != 0)
+    {
+      /* For non-GCC compilers expect their behavior is not compliant.  */
+
+      return -1;
+    }
+  cs = &producer[strlen ("GNU ")];
+  while (*cs && !isdigit (*cs))
+    cs++;
+  if (sscanf (cs, "%d.%d", &major, &minor) != 2)
+    {
+      /* Not recognized as GCC.  */
+
+      return -1;
+    }
+
+  if (major < 4)
+    return -1;
+  if (major > 4)
+    return INT_MAX;
+  return minor;
+}
+
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_utils;
 

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Jan Kratochvil]

On Thu, 08 Sep 2011 20:22:27 +0200, Jan Kratochvil wrote:
> gdb/
> 2011-09-08  Jan Kratochvil  <jan.kratochvil@redhat.com>
> 
> 	Code cleanup.
> 	* amd64-tdep.c (amd64_skip_prologue): Move the XMM code to ...
> 	(amd64_skip_xmm_prologue): ... this new function.  Describe its
> 	parameters.  No longer use amd64_prologue_line_bug.
> 	* defs.h (producer_is_gcc_ge_4): New declaration.
> 	* dwarf2read.c (producer_is_gcc_ge_4): Move to utils.c.
> 	(process_full_comp_unit): Update its caller.  Remove
> 	amd64_prologue_line_bug initialization.
> 	* symtab.h (struct symtab): Remove field amd64_prologue_line_bug.
> 	* utils.c (producer_is_gcc_ge_4): Moved here from dwarf2read.c.

Checked in:
	http://sourceware.org/ml/gdb-cvs/2011-09/msg00056.html


Thanks,
Jan

Re: [patch] workaround gcc46: prologue skip skips too far (PR 12435) #2

[Doug Evans]

On Fri, Sep 9, 2011 at 12:41 PM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> On Thu, 08 Sep 2011 20:22:27 +0200, Jan Kratochvil wrote:
>> gdb/
>> 2011-09-08  Jan Kratochvil  <jan.kratochvil@redhat.com>
>>
>>       Code cleanup.
>>       * amd64-tdep.c (amd64_skip_prologue): Move the XMM code to ...
>>       (amd64_skip_xmm_prologue): ... this new function.  Describe its
>>       parameters.  No longer use amd64_prologue_line_bug.
>>       * defs.h (producer_is_gcc_ge_4): New declaration.
>>       * dwarf2read.c (producer_is_gcc_ge_4): Move to utils.c.
>>       (process_full_comp_unit): Update its caller.  Remove
>>       amd64_prologue_line_bug initialization.
>>       * symtab.h (struct symtab): Remove field amd64_prologue_line_bug.
>>       * utils.c (producer_is_gcc_ge_4): Moved here from dwarf2read.c.
>
> Checked in:
>        http://sourceware.org/ml/gdb-cvs/2011-09/msg00056.html
>
>
> Thanks,
> Jan
>

"works for me".  Thanks.