value_fetch_lazy, ensure parent is not lazy and check parent for validity.

  http://sourceware.org/ml/gdb-patches/2013-07/msg00316.html

gdb/ChangeLog

        * value.c (value_fetch_lazy): Ensure parent value is not lazy
        before checking which bits of the parent, not the child, value are
        valid.

gdb/testsuite/ChangeLog

        * gdb.dwarf2/pieces-optimized-out.exp: New file.
        * gdb.dwarf2/pieces-optimized-out.c: New file.
        * gdb.dwarf2/pieces-optimized-out.S: New file.

6 files changed, 660 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 825599d..fd02aa4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2013-07-30  Andrew Burgess  <aburgess@broadcom.com>
+
+	* value.c (value_fetch_lazy): Ensure parent value is not lazy
+	before checking which bits of the parent, not the child, value are
+	valid.
+
 2013-07-30  Muhammad Bilal  <mbilal@codesorcery.com>
 
 	PR gdb/15715
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b90def4..666d083 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2013-07-30  Andrew Burgess  <aburgess@broadcom.com>
+
+	* gdb.dwarf2/pieces-optimized-out.exp: New file.
+	* gdb.dwarf2/pieces-optimized-out.c: New file.
+	* gdb.dwarf2/pieces-optimized-out.S: New file.
+
 2013-07-30  Muhammad Bilal  <mbilal@codesourcery.com>
 
 	PR gdb/15715
diff --git a/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.S b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.S
new file mode 100644
index 0000000..06aa707
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.S
@@ -0,0 +1,548 @@
+/*
+   Copyright 2010-2013 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 was compiled with gcc version 4.7.2 using:
+        gcc -O3 -m32 -g -o pieces-optimized-out.S -S pieces-optimized-out.c
+   The contents of this file are otherwise unmodified.  */
+
+        .file	"pieces-optimized-out.c"
+	.text
+.Ltext0:
+	.p2align 4,,15
+	.globl	foo
+	.type	foo, @function
+foo:
+.LFB0:
+	.file 1 "pieces-optimized-out.c"
+	.loc 1 33 0
+.LVL0:
+	.loc 1 35 0
+	movl	4(%esp), %eax
+	ret
+.LFE0:
+	.size	foo, .-foo
+	.section	.text.startup,"ax",@progbits
+	.p2align 4,,15
+	.globl	main
+	.type	main, @function
+main:
+.LFB1:
+	.loc 1 39 0
+.LVL1:
+	subl	$4, %esp
+.LCFI0:
+	.loc 1 44 0
+	movl	$10, (%esp)
+	call	foo
+.LVL2:
+	.loc 1 46 0
+	addl	$4, %esp
+.LCFI1:
+	.loc 1 45 0
+	addl	$20, %eax
+.LVL3:
+	.loc 1 46 0
+	ret
+.LFE1:
+	.size	main, .-main
+	.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	.LFB0
+	.long	.LFE0-.LFB0
+	.align 4
+.LEFDE0:
+.LSFDE2:
+	.long	.LEFDE2-.LASFDE2
+.LASFDE2:
+	.long	.Lframe0
+	.long	.LFB1
+	.long	.LFE1-.LFB1
+	.byte	0x4
+	.long	.LCFI0-.LFB1
+	.byte	0xe
+	.uleb128 0x8
+	.byte	0x4
+	.long	.LCFI1-.LCFI0
+	.byte	0xe
+	.uleb128 0x4
+	.align 4
+.LEFDE2:
+	.section	.eh_frame,"a",@progbits
+.Lframe1:
+	.long	.LECIE1-.LSCIE1
+.LSCIE1:
+	.long	0
+	.byte	0x1
+	.string	""
+	.uleb128 0x1
+	.sleb128 -4
+	.byte	0x8
+	.byte	0xc
+	.uleb128 0x4
+	.uleb128 0x4
+	.byte	0x88
+	.uleb128 0x1
+	.align 4
+.LECIE1:
+.LSFDE5:
+	.long	.LEFDE5-.LASFDE5
+.LASFDE5:
+	.long	.LASFDE5-.Lframe1
+	.long	.LFB0
+	.long	.LFE0-.LFB0
+	.align 4
+.LEFDE5:
+.LSFDE7:
+	.long	.LEFDE7-.LASFDE7
+.LASFDE7:
+	.long	.LASFDE7-.Lframe1
+	.long	.LFB1
+	.long	.LFE1-.LFB1
+	.byte	0x4
+	.long	.LCFI0-.LFB1
+	.byte	0xe
+	.uleb128 0x8
+	.byte	0x4
+	.long	.LCFI1-.LCFI0
+	.byte	0xe
+	.uleb128 0x4
+	.align 4
+.LEFDE7:
+	.text
+.Letext0:
+	.section	.debug_info,"",@progbits
+.Ldebug_info0:
+	.long	0xe4
+	.value	0x2
+	.long	.Ldebug_abbrev0
+	.byte	0x4
+	.uleb128 0x1
+	.long	.LASF0
+	.byte	0x1
+	.long	.LASF1
+	.long	.LASF2
+	.long	.Ldebug_ranges0+0
+	.long	0
+	.long	0
+	.long	.Ldebug_line0
+	.uleb128 0x2
+	.string	"str"
+	.byte	0xc
+	.byte	0x1
+	.byte	0x17
+	.long	0x6c
+	.uleb128 0x3
+	.string	"a"
+	.byte	0x1
+	.byte	0x19
+	.long	0x6c
+	.byte	0x2
+	.byte	0x23
+	.uleb128 0
+	.uleb128 0x3
+	.string	"b"
+	.byte	0x1
+	.byte	0x1a
+	.long	0x6c
+	.byte	0x2
+	.byte	0x23
+	.uleb128 0x4
+	.uleb128 0x4
+	.string	"c"
+	.byte	0x1
+	.byte	0x1b
+	.long	0x6c
+	.byte	0x4
+	.byte	0x3
+	.byte	0x1d
+	.byte	0x2
+	.byte	0x23
+	.uleb128 0x8
+	.uleb128 0x4
+	.string	"d"
+	.byte	0x1
+	.byte	0x1c
+	.long	0x6c
+	.byte	0x4
+	.byte	0x3
+	.byte	0x1a
+	.byte	0x2
+	.byte	0x23
+	.uleb128 0x8
+	.byte	0
+	.uleb128 0x5
+	.byte	0x4
+	.byte	0x5
+	.string	"int"
+	.uleb128 0x6
+	.byte	0x1
+	.string	"foo"
+	.byte	0x1
+	.byte	0x20
+	.byte	0x1
+	.long	0x6c
+	.long	.LFB0
+	.long	.LFE0
+	.byte	0x2
+	.byte	0x74
+	.sleb128 4
+	.byte	0x1
+	.long	0x9f
+	.uleb128 0x7
+	.string	"arg"
+	.byte	0x1
+	.byte	0x20
+	.long	0x6c
+	.byte	0x2
+	.byte	0x91
+	.sleb128 0
+	.byte	0
+	.uleb128 0x8
+	.byte	0x1
+	.long	.LASF3
+	.byte	0x1
+	.byte	0x26
+	.byte	0x1
+	.long	0x6c
+	.long	.LFB1
+	.long	.LFE1
+	.long	.LLST0
+	.byte	0x1
+	.uleb128 0x9
+	.string	"s"
+	.byte	0x1
+	.byte	0x28
+	.long	0x29
+	.byte	0x6
+	.byte	0x35
+	.byte	0x9f
+	.byte	0x93
+	.uleb128 0x4
+	.byte	0x93
+	.uleb128 0x8
+	.uleb128 0xa
+	.string	"v"
+	.byte	0x1
+	.byte	0x29
+	.long	0x6c
+	.long	.LLST1
+	.uleb128 0xb
+	.long	.LVL2
+	.long	0x73
+	.uleb128 0xc
+	.byte	0x2
+	.byte	0x74
+	.sleb128 0
+	.byte	0x1
+	.byte	0x3a
+	.byte	0
+	.byte	0
+	.byte	0
+	.section	.debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+	.uleb128 0x1
+	.uleb128 0x11
+	.byte	0x1
+	.uleb128 0x25
+	.uleb128 0xe
+	.uleb128 0x13
+	.uleb128 0xb
+	.uleb128 0x3
+	.uleb128 0xe
+	.uleb128 0x1b
+	.uleb128 0xe
+	.uleb128 0x55
+	.uleb128 0x6
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x52
+	.uleb128 0x1
+	.uleb128 0x10
+	.uleb128 0x6
+	.byte	0
+	.byte	0
+	.uleb128 0x2
+	.uleb128 0x13
+	.byte	0x1
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x1
+	.uleb128 0x13
+	.byte	0
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0xd
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x38
+	.uleb128 0xa
+	.byte	0
+	.byte	0
+	.uleb128 0x4
+	.uleb128 0xd
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0xd
+	.uleb128 0xb
+	.uleb128 0xc
+	.uleb128 0xb
+	.uleb128 0x38
+	.uleb128 0xa
+	.byte	0
+	.byte	0
+	.uleb128 0x5
+	.uleb128 0x24
+	.byte	0
+	.uleb128 0xb
+	.uleb128 0xb
+	.uleb128 0x3e
+	.uleb128 0xb
+	.uleb128 0x3
+	.uleb128 0x8
+	.byte	0
+	.byte	0
+	.uleb128 0x6
+	.uleb128 0x2e
+	.byte	0x1
+	.uleb128 0x3f
+	.uleb128 0xc
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x27
+	.uleb128 0xc
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x12
+	.uleb128 0x1
+	.uleb128 0x40
+	.uleb128 0xa
+	.uleb128 0x2117
+	.uleb128 0xc
+	.uleb128 0x1
+	.uleb128 0x13
+	.byte	0
+	.byte	0
+	.uleb128 0x7
+	.uleb128 0x5
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x2
+	.uleb128 0xa
+	.byte	0
+	.byte	0
+	.uleb128 0x8
+	.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 0x49
+	.uleb128 0x13
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x12
+	.uleb128 0x1
+	.uleb128 0x40
+	.uleb128 0x6
+	.uleb128 0x2117
+	.uleb128 0xc
+	.byte	0
+	.byte	0
+	.uleb128 0x9
+	.uleb128 0x34
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x2
+	.uleb128 0xa
+	.byte	0
+	.byte	0
+	.uleb128 0xa
+	.uleb128 0x34
+	.byte	0
+	.uleb128 0x3
+	.uleb128 0x8
+	.uleb128 0x3a
+	.uleb128 0xb
+	.uleb128 0x3b
+	.uleb128 0xb
+	.uleb128 0x49
+	.uleb128 0x13
+	.uleb128 0x2
+	.uleb128 0x6
+	.byte	0
+	.byte	0
+	.uleb128 0xb
+	.uleb128 0x4109
+	.byte	0x1
+	.uleb128 0x11
+	.uleb128 0x1
+	.uleb128 0x31
+	.uleb128 0x13
+	.byte	0
+	.byte	0
+	.uleb128 0xc
+	.uleb128 0x410a
+	.byte	0
+	.uleb128 0x2
+	.uleb128 0xa
+	.uleb128 0x2111
+	.uleb128 0xa
+	.byte	0
+	.byte	0
+	.byte	0
+	.section	.debug_loc,"",@progbits
+.Ldebug_loc0:
+.LLST0:
+	.long	.LFB1
+	.long	.LCFI0
+	.value	0x2
+	.byte	0x74
+	.sleb128 4
+	.long	.LCFI0
+	.long	.LCFI1
+	.value	0x2
+	.byte	0x74
+	.sleb128 8
+	.long	.LCFI1
+	.long	.LFE1
+	.value	0x2
+	.byte	0x74
+	.sleb128 4
+	.long	0
+	.long	0
+.LLST1:
+	.long	.LVL1
+	.long	.LVL2
+	.value	0x2
+	.byte	0x3a
+	.byte	0x9f
+	.long	.LVL2
+	.long	.LVL3
+	.value	0x3
+	.byte	0x70
+	.sleb128 10
+	.byte	0x9f
+	.long	.LVL3
+	.long	.LFE1
+	.value	0x3
+	.byte	0x70
+	.sleb128 -10
+	.byte	0x9f
+	.long	0
+	.long	0
+	.section	.debug_aranges,"",@progbits
+	.long	0x24
+	.value	0x2
+	.long	.Ldebug_info0
+	.byte	0x4
+	.byte	0
+	.value	0
+	.value	0
+	.long	.Ltext0
+	.long	.Letext0-.Ltext0
+	.long	.LFB1
+	.long	.LFE1-.LFB1
+	.long	0
+	.long	0
+	.section	.debug_ranges,"",@progbits
+.Ldebug_ranges0:
+	.long	.Ltext0
+	.long	.Letext0
+	.long	.LFB1
+	.long	.LFE1
+	.long	0
+	.long	0
+	.section	.debug_line,"",@progbits
+.Ldebug_line0:
+	.section	.debug_str,"MS",@progbits,1
+.LASF2:
+	.string	"/home/username/"
+.LASF1:
+	.string	"pieces-optimized-out.c"
+.LASF0:
+	.string	"GNU C 4.7.2"
+.LASF3:
+	.string	"main"
+	.ident	"GCC: (GNU) 4.7.2"
+	.section	.note.GNU-stack,"",@progbits
diff --git a/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.c b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.c
new file mode 100644
index 0000000..2bf9cf8
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.c
@@ -0,0 +1,47 @@
+/* Copyright (C) 2013 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 not actually compiled, the .S file is committed alongside
+   this file.  The reason is that changes to the compiler might result
+   in different debug information being created, this could break the
+   test.  */
+
+struct str
+{
+  int a;
+  int b;
+  int c : 3;
+  int d : 3;
+};
+
+int __attribute__ ((noinline))
+foo (int arg)
+{  
+  return arg;
+}
+
+int
+main ( void )
+{
+  struct str s = {5, 7, 1, 2};
+  int v;
+
+  v = (s.a << 1);
+  v += foo (v);
+  return v + 5 + s.a;
+}
+
diff --git a/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.exp b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.exp
new file mode 100644
index 0000000..2e4d028
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/pieces-optimized-out.exp
@@ -0,0 +1,49 @@
+# Copyright 2013 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
+# Test some DWARF piece operators.
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+    return 0  
+}
+# This test can only be run on x86 targets.
+if {![is_x86_like_target]} {
+    return 0  
+}
+
+standard_testfile .S
+set csrcfile ${testfile}.c
+
+if {[prepare_for_testing ${testfile}.exp ${testfile} $srcfile]} {
+    return -1
+}
+
+if ![runto foo] {
+    return -1
+}
+
+# Move back up to main.
+gdb_test "up" "#1  $hex in main.*" "move up a frame"
+
+# Now take a look at the 's' structure.
+gdb_test "p s" \
+    " = {a = 5, b = <optimized out>, c = <optimized out>, d = <optimized out>}" \
+    "print s"
+gdb_test "p s.a" " = 5" "print s.a"
+gdb_test "p s.b" " = <optimized out>" "print s.b"
+gdb_test "p s.c" "value has been optimized out" "print s.c"
+gdb_test "p s.d" "value has been optimized out" "print s.d"
+
diff --git a/gdb/value.c b/gdb/value.c
index 04f325f..8e0f8c4 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -3433,7 +3433,10 @@ value_fetch_lazy (struct value *val)
       LONGEST offset = value_offset (val);
       LONGEST num;
 
-      if (!value_bits_valid (val,
+      if (value_lazy (parent))
+	value_fetch_lazy (parent);
+
+      if (!value_bits_valid (parent,
 			     TARGET_CHAR_BIT * offset + value_bitpos (val),
 			     value_bitsize (val)))
 	error (_("value has been optimized out"));