https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85310
Bug ID: 85310
Summary: optimization ignoring strlen() results
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: kees at outflux dot net
Target Milestone: ---
Created attachment 43889
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43889&action=edit
test case
Something is gcc 8 is broken when dealing with strlen() results.
The correct behavior is seen in earlier versions of the compiler:
$ gcc --version
gcc (Ubuntu 7.3.0-14ubuntu1) 7.3.0
...
$ gcc -Wall -O2 -o testcase testcase.c
$ ./testcase
MY_SIZE: 16
dst: 15
done...
The bad version happens in the current gcc trunk:
$ /home/kees/bin/gcc-snapshot/gcc --version
gcc (Ubuntu 20180322-1ubuntu1) 8.0.1 20180322 (experimental) [trunk revision
258755]
...
$ /home/kees/bin/gcc-snapshot/gcc -Wall -O2 -o testcase testcase.c
$ ./testcase
MY_SIZE: 16
dst: 32
done...
Segmentation fault (core dumped)
Checking with godbolt confirms there is no test against "16" in the output:
https://godbolt.org/g/63Sbir
