https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66305
Bug ID: 66305
Summary: -ffat-lto-objects create unreproducible objects
Product: gcc
Version: 5.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: lunar at debian dot org
Target Milestone: ---
Hi!
We are working in Debian—and I know other free software projects
care—in providing our users with a way to reproduce bit-for-bit
identical binary packages from the source and build enviroment.
See <https://wiki.debian.org/ReproducibleBuilds> for more information.
Python packages in Debian are built with `-flto -ffat-lto-objects`
on architectures that support it. Sadly, this makes the resulting
binary unreproducible.
For a trivial test case:
$ cat a.c
int a(void) {
return 42;
}
$ gcc -flto -ffat-lto-objects -c a.c
$ strings a.o | grep lto_
.gnu.lto_.inline.4980dca9e6ae4d45
.gnu.lto_a.4980dca9e6ae4d45
.gnu.lto_.symbol_nodes.4980dca9e6ae4d45
.gnu.lto_.refs.4980dca9e6ae4d45
.gnu.lto_.decls.4980dca9e6ae4d45
.gnu.lto_.symtab.4980dca9e6ae4d45
.gnu.lto_.opts
__gnu_lto_v1
$ gcc -flto -ffat-lto-objects -c a.c
$ strings a.o | grep lto_
.gnu.lto_.inline.24c30dabb443e726
.gnu.lto_a.24c30dabb443e726
.gnu.lto_.symbol_nodes.24c30dabb443e726
.gnu.lto_.refs.24c30dabb443e726
.gnu.lto_.decls.24c30dabb443e726
.gnu.lto_.symtab.24c30dabb443e726
.gnu.lto_.opts
__gnu_lto_v1
Would it be possible to make the section names deterministic?
