https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96002
Bug ID: 96002
Summary: Wrong argument value shown by gdb at Og
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: wrong-debug
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: massarelli at diag dot uniroma1.it
Target Milestone: ---
Keywords: wrong-debug
The second time line 5 is hit arguments p_21 is assigned a wrong value.
$ cat -n a.c
1 int a, c;
2 int *b[3];
3 void d(int e, short f, int g, char p_21) {
4 int h;
5 for (; c < 3; c++)
6 b[c] = &h;
7 }
8 int main() { d(a, 0, 1, 0); }
$ cat a.c
int a, c;
int *b[3];
void d(int e, short f, int g, char p_21) {
int h;
for (; c < 3; c++)
b[c] = &h;
}
int main() { d(a, 0, 1, 0); }
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ./configure --prefix=/tmp/gcc_build --disable-multilib
--enable-languages=c,c++
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.0.0 20200624 (experimental) (GCC)
$ gcc -Og -g -o opt a.c
$ gdb opt
Reading symbols from opt...
(gdb) b main
Breakpoint 1 at 0x4004ad: file a.c, line 8.
(gdb) r
Starting program: opt
Breakpoint 1, main () at a.c:8
8 int main() { d(a, 0, 1, 0); }
(gdb) s
d (e=0, f=f@entry=0, g=g@entry=1, p_21=p_21@entry=0 '\000') at a.c:5
5 for (; c < 3; c++)
(gdb) s
6 b[c] = &h;
(gdb) bt
#0 d (e=0, f=f@entry=0, g=g@entry=1, p_21=p_21@entry=0 '\000') at a.c:6
#1 0x00000000004004c7 in main () at a.c:8
(gdb) s
5 for (; c < 3; c++)
(gdb) bt
#0 d (e=0, f=f@entry=0, g=g@entry=1, p_21=124 '|', p_21@entry=0 '\000') at
a.c:5
#1 0x00000000004004c7 in main () at a.c:8
(gdb)
