https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112708
Bug ID: 112708
Summary: "gcc -fsanitize=address" produces wrong debug info for
variables in function prologue
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: bruno at clisp dot org
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
As "gcc -fsanitize=address" finds several categories of memory related bugs,
I'm trying to use CC="gcc -fsanitize=address" everywhere. Unfortunately,
in the following case, a variable's value during a function prologue is
wrong when displayed by gdb. The value is displayed correctly when I don't
use the option -fsanitize=address. Which means that the culprit is gcc.
How to reproduce:
1. $ wget https://ftp.gnu.org/gnu/gettext/gettext-0.22.tar.xz
2. $ tar xf gettext-0.22.tar.xz
3. $ cd gettext-0.22
4. $ GCC13DIR=/some/directory/with/gcc-13.2.0
$ PATH=$GCC13DIR/bin:$PATH
Verify it:
$ gcc --version
5. $ CC="gcc -fsanitize=address" CXX="g++ -fsanitize=address
-Wl,-rpath,$GCC13DIR/lib64" CFLAGS=-ggdb ./configure --disable-shared
6. $ make
7. $ cd gettext-tools/src
8. $ cat > foo.vala <<\EOF
primary_text.set_markup(
"<span size=\"large\" weight=\"bold\">%s</span>".printf(_("Welcome
to Shotwell!")));
EOF
9.
$ gdb xgettext
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Reading symbols from xgettext...
(gdb) break xg-message.c:383
Breakpoint 1 at 0x41cad1: file xg-message.c, line 383.
(gdb) run -o - foo.vala
Starting program: /tmp/gettext-0.22/gettext-tools/src/xgettext -o - foo.vala
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Breakpoint 1, remember_a_message (mlp=0x60e000000040, msgctxt=0x0,
msgid=0x603000000a30 "Welcome to Shotwell!", is_utf8=true, pluralp=false,
context=..., pos=0x6100000004c0, extracted_comment=0x0, comment=0x0,
comment_is_utf8=false) at xg-message.c:383
383 set_format_flags_from_context (is_format, context, mp->msgid, pos,
"msgid");
(gdb) print context
$1 = {is_format1 = 3, pass_format1 = 0, is_format2 = 0, pass_format2 = 0,
is_format3 = 0, pass_format3 = 0, is_format4 = 0, pass_format4 = 0}
(gdb) step
set_format_flags_from_context (is_format=0x7fffffffc620, context=...,
string=0x603000000a30 "Welcome to Shotwell!", pos=0x6100000004c0,
pretty_msgstr=0x6f0d40 "msgid") at xg-message.c:50
50 flag_context_ty context, const char
*string,
(gdb) print context
$2 = {is_format1 = 0, pass_format1 = 0, is_format2 = 2, pass_format2 = 0,
is_format3 = 5, pass_format3 = 0, is_format4 = 7, pass_format4 = 0}
(gdb) next
55 if (context.is_format1 != undecided
(gdb) print context
$3 = {is_format1 = 3, pass_format1 = 0, is_format2 = 0, pass_format2 = 0,
is_format3 = 0, pass_format3 = 0, is_format4 = 0, pass_format4 = 0}
The variable 'context' is passed from xg-message.c:383 to
set_format_flags_from_context.
The value printed as $1 and $3 is correct.
The value printed as $2 is nonsense.
