Fix resolving of variables at locations lists in prelinked libs (BZ 466901).

Index: gdb-6.8.50.20081128/gdb/dwarf2loc.c
===================================================================
--- gdb-6.8.50.20081128.orig/gdb/dwarf2loc.c	2008-12-08 11:00:45.000000000 +0100
+++ gdb-6.8.50.20081128/gdb/dwarf2loc.c	2008-12-08 18:02:49.000000000 +0100
@@ -55,7 +55,9 @@ find_location_expression (struct dwarf2_
   CORE_ADDR low, high;
   gdb_byte *loc_ptr, *buf_end;
   int length;
-  struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu);
+  struct objfile *objfile1 = dwarf2_per_cu_objfile (baton->per_cu);
+  struct objfile *objfile = objfile1->separate_debug_objfile
+			    ? objfile1->separate_debug_objfile : objfile1;
   struct gdbarch *gdbarch = get_objfile_arch (objfile);
   unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu);
   CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
Index: gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked.exp
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked.exp	2008-12-08 18:00:43.000000000 +0100
@@ -0,0 +1,102 @@
+# Copyright 2008 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 2 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+# Minimal DWARF-2 unit test
+
+# This test can only be run on i386/x86_64 targets which support DWARF-2.
+# For now pick a sampling of likely targets.
+if {(![istarget *-*-linux*]
+     && ![istarget *-*-gnu*]
+     && ![istarget *-*-elf*]
+     && ![istarget *-*-openbsd*])
+    || (![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"])} {
+    return 0  
+}
+
+set testfile "dw2-loclist-prelinked"
+set srcfuncfile ${testfile}-func.S
+set binsharedfuncfile ${objdir}/${subdir}/${testfile}.so
+set srcmainfile ${testfile}-main.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+remote_exec build "rm -f ${binfile}"
+
+# get the value of gcc_compiled
+if [get_compiler_info ${binfile}] {
+    return -1
+}
+
+# This test can only be run on gcc as we use additional_flags=FIXME
+if {$gcc_compiled == 0} {
+    return 0
+}
+
+if  { [gdb_compile_shlib "${srcdir}/${subdir}/${srcfuncfile}" "${binsharedfuncfile}" {debug additional_flags=-m32}] != "" } {
+    untested "Couldn't compile test library"
+    return -1
+}
+
+# The new separate debug info file will be stored in the .debug subdirectory.
+
+if [gdb_gnu_strip_debug ${binsharedfuncfile}] {
+    # check that you have a recent version of strip and objcopy installed
+    unsupported "cannot produce separate debug info files"
+    return -1
+}
+
+if {[catch "system \"/usr/sbin/prelink -qNR --no-exec-shield ${binsharedfuncfile}\""] != 0} {
+    # Maybe we don't have prelink.
+    return -1
+}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcmainfile}" \
+		   "${binfile}" executable [list debug additional_flags=-m32 shlib=${binsharedfuncfile}]] != "" } {
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+gdb_run_cmd
+
+gdb_test "" "Program received signal SIGABRT, Aborted..*" "Enter abort()"
+
+# Incorrect:
+# #0  0x00110430 in __kernel_vsyscall ()
+# No symbol table info available.
+# #1  0x003d44c0 in raise () from /lib/libc.so.6
+# No symbol table info available.
+# #2  0x003d5e88 in abort () from /lib/libc.so.6
+# No symbol table info available.
+# #3  0x44f10437 in func () at dw2-loclist-prelinked.c:8
+# 	i = Could not find the frame base for "func".
+
+# Correct:
+# #0  0x00110430 in __kernel_vsyscall ()
+# No symbol table info available.
+# #1  0x003d44c0 in raise () from /lib/libc.so.6
+# No symbol table info available.
+# #2  0x003d5e88 in abort () from /lib/libc.so.6
+# No symbol table info available.
+# #3  0x4ae36437 in func () at dw2-loclist-prelinked.c:8
+# 	i = 3827288
+# #4  0x0804851a in main () at ../../../gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked-main.c:24
+# No locals.
+
+# `abort' can get expressed as `*__GI_abort'.
+gdb_test "bt full" "in \[^ \]*abort \\(.*in func \\(.*\ti = -?\[0-9\].*in main \\(.*" "Backtrace after abort()"
Index: gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked-main.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked-main.c	2008-12-08 18:00:43.000000000 +0100
@@ -0,0 +1,26 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2008 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/>.  */
+
+/* dw2-loclist-prelinked-func.S */
+extern void func (void);
+
+int
+main (void)
+{
+  func ();
+  return 0;
+}
Index: gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked-func.S
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb-6.8.50.20081128/gdb/testsuite/gdb.dwarf2/dw2-loclist-prelinked-func.S	2008-12-08 18:00:43.000000000 +0100
@@ -0,0 +1,328 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2008 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/>.  */
+
+/*
+#include <stdlib.h>
+
+void
+func (void)
+{
+  int i;
+
+  abort ();
+}
+*/
+	.file	"dw2-loclist-prelinked.c"
+	.section	.debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+	.section	.debug_info,"",@progbits
+.Ldebug_info0:
+	.section	.debug_line,"",@progbits
+.Ldebug_line0:
+	.text
+.Ltext0:
+.globl func
+	.type	func, @function
+func:
+.LFB2:
+	.file 1 "dw2-loclist-prelinked.c"
+	.loc 1 5 0
+	pushl	%ebp
+.LCFI0:
+	movl	%esp, %ebp
+.LCFI1:
+	subl	$24, %esp
+.LCFI2:
+	.loc 1 8 0
+	call	abort
+.LFE2:
+	.size	func, .-func
+	.section	.debug_frame,"",@progbits
+.Lframe0:
+	.long	.LECIE0-.LSCIE0
+.LSCIE0:
+	.long	0xffffffff
+	.byte	0x1
+	.string	""
+	.uleb128 0x1
+	.sleb128 -4
+	.byte	0x8
+	.byte	0xc
+	.uleb128 0x4
+	.uleb128 0x4
+	.byte	0x88
+	.uleb128 0x1
+	.align 4
+.LECIE0:
+.LSFDE0:
+	.long	.LEFDE0-.LASFDE0
+.LASFDE0:
+	.long	.Lframe0
+	.long	.LFB2
+	.long	.LFE2-.LFB2
+	.byte	0x4
+	.long	.LCFI0-.LFB2
+	.byte	0xe
+	.uleb128 0x8
+	.byte	0x85
+	.uleb128 0x2
+	.byte	0x4
+	.long	.LCFI1-.LCFI0
+	.byte	0xd
+	.uleb128 0x5
+	.align 4
+.LEFDE0:
+	.text
+.Letext0:
+	.section	.debug_loc,"",@progbits
+.Ldebug_loc0:
+.LLST0:
+	.long	.LFB2-.Ltext0
+	.long	.LCFI0-.Ltext0
+	.value	0x2
+	.byte	0x74
+	.sleb128 4
+	.long	.LCFI0-.Ltext0
+	.long	.LCFI1-.Ltext0
+	.value	0x2
+	.byte	0x74
+	.sleb128 8
+	.long	.LCFI1-.Ltext0
+	.long	.LFE2-.Ltext0
+	.value	0x2
+	.byte	0x75
+	.sleb128 8
+	.long	0x0
+	.long	0x0
+	.section	.debug_info
+	.long	0x94
+	.value	0x2
+	.long	.Ldebug_abbrev0
+	.byte	0x4
+	.uleb128 0x1
+	.long	.LASF10
+	.byte	0x1
+	.long	.LASF11
+	.long	.LASF12
+	.long	.Ltext0
+	.long	.Letext0
+	.long	.Ldebug_line0
+	.uleb128 0x2
+	.byte	0x4
+	.byte	0x7
+	.long	.LASF0
+	.uleb128 0x3
+	.byte	0x4
+	.byte	0x5
+	.string	"int"
+	.uleb128 0x2
+	.byte	0x4
+	.byte	0x5
+	.long	.LASF1
+	.uleb128 0x2
+	.byte	0x1
+	.byte	0x8
+	.long	.LASF2
+	.uleb128 0x2
+	.byte	0x2
+	.byte	0x7
+	.long	.LASF3
+	.uleb128 0x2
+	.byte	0x4
+	.byte	0x7
+	.long	.LASF4
+	.uleb128 0x2
+	.byte	0x1
+	.byte	0x6
+	.long	.LASF5
+	.uleb128 0x2
+	.byte	0x2
+	.byte	0x5
+	.long	.LASF6
+	.uleb128 0x2
+	.byte	0x8
+	.byte	0x5
+	.long	.LASF7
+	.uleb128 0x2
+	.byte	0x8
+	.byte	0x7
+	.long	.LASF8
+	.uleb128 0x4
+	.byte	0x4
+	.byte	0x7
+	.uleb128 0x2
+	.byte	0x1
+	.byte	0x6
+	.long	.LASF9
+	.uleb128 0x5
+	.byte	0x1
+	.long	.LASF13
+	.byte	0x1
+	.byte	0x5
+	.byte	0x1
+	.long	.LFB2
+	.long	.LFE2
+	.long	.LLST0
+	.uleb128 0x6
+	.string	"i"
+	.byte	0x1
+	.byte	0x6
+	.long	0x2c
+	.byte	0x2
+	.byte	0x91
+	.sleb128 -12
+	.byte	0x0
+	.byte	0x0
+	.section	.debug_abbrev
+	.uleb128 0x1
+	.uleb128 0x11
+	.byte	0x1
+	.uleb128 0x25
+	.uleb128 0xe
+	.uleb128 0x13
+	.uleb128 0xb
+	.uleb128 0x3
+	.uleb128 0xe
+	.uleb128 0x1b
+	.uleb128 0xe
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x12
+	.uleb128 0x1
+	.uleb128 0x10
+	.uleb128 0x6
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x2
+	.uleb128 0x24
+	.byte	0x0
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0x3e
+	.uleb128 0xb
+	.uleb128 0x3
+	.uleb128 0xe
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x3
+	.uleb128 0x24
+	.byte	0x0
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0x3e
+	.uleb128 0xb
+	.uleb128 0x3
+	.uleb128 0x8
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x4
+	.uleb128 0x24
+	.byte	0x0
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0x3e
+	.uleb128 0xb
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x5
+	.uleb128 0x2e
+	.byte	0x1
+	.uleb128 0x3f
+	.uleb128 0xc
+	.uleb128 0x3
+	.uleb128 0xe
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x27
+	.uleb128 0xc
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x12
+	.uleb128 0x1
+	.uleb128 0x40
+	.uleb128 0x6
+	.byte	0x0
+	.byte	0x0
+	.uleb128 0x6
+	.uleb128 0x34
+	.byte	0x0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x2
+	.uleb128 0xa
+	.byte	0x0
+	.byte	0x0
+	.byte	0x0
+	.section	.debug_pubnames,"",@progbits
+	.long	0x17
+	.value	0x2
+	.long	.Ldebug_info0
+	.long	0x98
+	.long	0x75
+	.string	"func"
+	.long	0x0
+	.section	.debug_aranges,"",@progbits
+	.long	0x1c
+	.value	0x2
+	.long	.Ldebug_info0
+	.byte	0x4
+	.byte	0x0
+	.value	0x0
+	.value	0x0
+	.long	.Ltext0
+	.long	.Letext0-.Ltext0
+	.long	0x0
+	.long	0x0
+	.section	.debug_str,"MS",@progbits,1
+.LASF7:
+	.string	"long long int"
+.LASF0:
+	.string	"unsigned int"
+.LASF11:
+	.string	"dw2-loclist-prelinked.c"
+.LASF12:
+	.string	"gdb-6.8/gdb/testsuite/gdb.dwarf2"
+.LASF4:
+	.string	"long unsigned int"
+.LASF8:
+	.string	"long long unsigned int"
+.LASF2:
+	.string	"unsigned char"
+.LASF9:
+	.string	"char"
+.LASF1:
+	.string	"long int"
+.LASF3:
+	.string	"short unsigned int"
+.LASF5:
+	.string	"signed char"
+.LASF10:
+	.string	"GNU C 4.3.2 20081007 (Red Hat 4.3.2-6)"
+.LASF13:
+	.string	"func"
+.LASF6:
+	.string	"short int"
+	.ident	"GCC: (GNU) 4.3.2 20081007 (Red Hat 4.3.2-6)"
+	.section	.note.GNU-stack,"",@progbits