https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89454
Bug ID: 89454
Summary: gcc generates wrong debug information at -Og
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: qrzhang at gatech dot edu
Target Milestone: ---
It bug affects the latest trunk.
It also affects gcc-8 to gcc-4.8.
With "-Og", it incorrectly prints "l=0".
$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/9.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 9.0.1 20190222 (experimental) [trunk revision 269113] (GCC)
$ cat abc.c
int a;
int main() {
char l = 0;
if (a)
;
else
l = 10 || 0;
optimize_me_not();
}
$ cat cmds
b 8
r
p l
kill
q
$ cat outer.c
optimize_me_not() {}
$ gcc-trunk -g abc.c outer.c
$ gdb -x cmds -batch a.out
Breakpoint 1 at 0x40049c: file abc.c, line 8.
Breakpoint 1, main () at abc.c:8
8 optimize_me_not();
$1 = 1 '\001'
Kill the program being debugged? (y or n) [answered Y; input not from terminal]
$ gcc-trunk -g abc.c outer.c -Og
$ gdb -x cmds -batch a.out
Breakpoint 1 at 0x400486: file abc.c, line 8.
Breakpoint 1, main () at abc.c:8
8 optimize_me_not();
$1 = 0 '\000'
Kill the program being debugged? (y or n) [answered Y; input not from terminal]
