aboutsummaryrefslogtreecommitdiff
path: root/gdb/value.h
diff options
context:
space:
mode:
authorPedro Alves <palves@redhat.com>2013-06-28 12:36:48 +0000
committerPedro Alves <palves@redhat.com>2013-06-28 12:36:48 +0000
commit4eb591088281a5374a828ea6bf6e25eb33d30e2a (patch)
tree09d4b1446c0d9e17b0d0ee9b122f9c81cc0548ba /gdb/value.h
parent257b6bec774c0b9ec2c52494fc4898f472fcdbb8 (diff)
downloadgdb-4eb591088281a5374a828ea6bf6e25eb33d30e2a.zip
gdb-4eb591088281a5374a828ea6bf6e25eb33d30e2a.tar.gz
gdb-4eb591088281a5374a828ea6bf6e25eb33d30e2a.tar.bz2
[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.h')
-rw-r--r--gdb/value.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/gdb/value.h b/gdb/value.h
index 4e839d3..8a66aa4 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -463,7 +463,12 @@ extern void mark_value_bytes_unavailable (struct value *value,
value_available_contents_eq(val, 4, val, 12, 2) => 1
value_available_contents_eq(val, 4, val, 12, 4) => 0
value_available_contents_eq(val, 3, val, 4, 4) => 0
-*/
+
+ We only know whether a value chunk is available if we've tried to
+ read it. As this routine is used by printing routines, which may
+ be printing values in the value history, long after the inferior is
+ gone, it works with const values. Therefore, this routine must not
+ be called with lazy values. */
extern int value_available_contents_eq (const struct value *val1, int offset1,
const struct value *val2, int offset2,