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| author | Pedro Alves <palves@redhat.com> | 2013-06-28 12:36:47 +0000 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2013-06-28 12:36:47 +0000 |
| commit | d01affbdda5f73c50491bf665864f2480bc92418 (patch) | |
| tree | abf1f498c64d978325900055eb22391af3ebe2a3 /gdb/value.c | |
| parent | 296ea2099b85c831c6a8ab28eb438ae79b18800e (diff) | |
| download | gdb-d01affbdda5f73c50491bf665864f2480bc92418.tar.gz | |
[PR tui/14880] Fetch values before comparing their contents.
PR tui/14880 shows a reproducer that triggers this assertion:
int
value_available_contents_eq (const struct value *val1, int offset1,
const struct value *val2, int offset2,
int length)
{
int idx1 = 0, idx2 = 0;
/* This routine is used by printing routines, where we should
already have read the value. Note that we only know whether a
value chunk is available if we've tried to read it. */
gdb_assert (!val1->lazy && !val2->lazy);
(top-gdb) bt
#0 internal_error (file=0x88a26c "../../src/gdb/value.c", line=549, string=0x88a220 "%s: Assertion `%s' failed.") at ../../src/gdb/utils.c:844
#1 0x000000000057b9cd in value_available_contents_eq (val1=0x10fa900, offset1=0, val2=0x10f9e10, offset2=0, length=8) at ../../src/gdb/value.c:549
#2 0x00000000004fd756 in tui_get_register (frame=0xd5c430, data=0x109a548, regnum=0, changedp=0x109a560) at ../../src/gdb/tui/tui-regs.c:736
#3 0x00000000004fd111 in tui_check_register_values (frame=0xd5c430) at ../../src/gdb/tui/tui-regs.c:521
#4 0x0000000000501884 in tui_check_data_values (frame=0xd5c430) at ../../src/gdb/tui/tui-windata.c:234
#5 0x00000000004f976f in tui_selected_frame_level_changed_hook (level=1) at ../../src/gdb/tui/tui-hooks.c:222
#6 0x00000000006f0681 in select_frame (fi=0xd5c430) at ../../src/gdb/frame.c:1490
#7 0x00000000005dd94b in up_silently_base (count_exp=0x0) at ../../src/gdb/stack.c:2268
#8 0x00000000005dd985 in up_command (count_exp=0x0, from_tty=1) at ../../src/gdb/stack.c:2280
#9 0x00000000004dc5cf in do_cfunc (c=0xd3f720, args=0x0, from_tty=1) at ../../src/gdb/cli/cli-decode.c:113
#10 0x00000000004df664 in cmd_func (cmd=0xd3f720, args=0x0, from_tty=1) at ../../src/gdb/cli/cli-decode.c:1888
#11 0x00000000006e43e1 in execute_command (p=0xc7e6c2 "", from_tty=1) at ../../src/gdb/top.c:489
The fix is to fetch the value before comparing the contents. The
comment additions to value.h explain why it can't be
value_available_contents_eq itself that fetches the contents.
Tested on x86_64 Fedora 17.
gdb/
2013-06-28 Pedro Alves <palves@redhat.com>
PR tui/14880
* tui/tui-regs.c (tui_get_register): Fetch register value contents
before checking whether they're available.
* value.c (value_available_contents_eq): Change comment.
* value.h (value_available_contents_eq): Expand comment.
Diffstat (limited to 'gdb/value.c')
| -rw-r--r-- | gdb/value.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/gdb/value.c b/gdb/value.c index ee3c9983036..fae8b984711 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -543,9 +543,7 @@ value_available_contents_eq (const struct value *val1, int offset1, { int idx1 = 0, idx2 = 0; - /* This routine is used by printing routines, where we should - already have read the value. Note that we only know whether a - value chunk is available if we've tried to read it. */ + /* See function description in value.h. */ gdb_assert (!val1->lazy && !val2->lazy); while (length > 0) |