https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115323
Bug ID: 115323
Summary: [10/11/12 Regression] signed integer overflow check
missing at -O0, -O2, -O3, -Os
Product: gcc
Version: 12.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: bic60176 at gmail dot com
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
Target Milestone: ---
Created attachment 58328
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58328&action=edit
testcase
OS: Ubuntu 22.04.3 LTS
We found some cases that UBSAN missed checking if there's a signed integer
overflow behavior when compiling with gcc-12.3.0 at optimization levels -O0,
-O2, -O3, -Os.
When compiling with gcc-12.3.0 at optimization level -O1, UBSAN can detect the
undefined behavior.
$ ../compiler-builds/gcc-12.3.0_build/bin/gcc -fsanitize=undefined -g -lgcc_s
-I/home/csmith/include/csmith-2.3.0 -O0 testcase.c -o exec
$ timeout 1s ./exec 2>exec.err
$ cat exec.err
$ ../compiler-builds/gcc-12.3.0_build/bin/gcc -fsanitize=undefined -g -lgcc_s
-I/home/csmith/include/csmith-2.3.0 -O1 testcase.c -o exec
$ timeout 1s ./exec 2>exec.err
$ cat exec.err
testcase.c:26:59: runtime error: signed integer overflow: 65495 * 65529 cannot
be represented in type 'int'
