[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 Jakub Jelinek changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #9 from Jakub Jelinek --- Fixed.
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #8 from CVS Commits --- The releases/gcc-9 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:eb253e4148ba1a79789c623a062d43a126ec4c31 commit r9-10088-geb253e4148ba1a79789c623a062d43a126ec4c31 Author: Jakub Jelinek Date: Wed Jul 14 10:22:50 2021 +0200 godump: Fix -fdump-go-spec= reproduceability issue [PR101407] pot_dummy_types is a hash_set from whose traversal the code prints some type lines. hash_set normally uses default_hash_traits which for pointer types (the hash set hashes const char *) uses pointer_hash which hashes the addresses of the pointers except of the least significant 3 bits. With address space randomization, that results in non-determinism in the -fdump-go-specs= generated file, each invocation can have different order of the lines emitted from pot_dummy_types traversal. This patch fixes it by hashing the string contents instead to make the hashes reproduceable. 2021-07-14 Jakub Jelinek PR go/101407 * godump.c (godump_str_hash): New type. (godump_container::pot_dummy_types): Use string_hash instead of ptr_hash in the hash_set. (cherry picked from commit 3be762c2ed79e36b9c8faaea2be04725c967a34e)
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #7 from CVS Commits --- The releases/gcc-10 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:2c7087f46bb8c3f698cc475ece3786582bd34da0 commit r10-10631-g2c7087f46bb8c3f698cc475ece3786582bd34da0 Author: Jakub Jelinek Date: Wed Jul 14 10:22:50 2021 +0200 godump: Fix -fdump-go-spec= reproduceability issue [PR101407] pot_dummy_types is a hash_set from whose traversal the code prints some type lines. hash_set normally uses default_hash_traits which for pointer types (the hash set hashes const char *) uses pointer_hash which hashes the addresses of the pointers except of the least significant 3 bits. With address space randomization, that results in non-determinism in the -fdump-go-specs= generated file, each invocation can have different order of the lines emitted from pot_dummy_types traversal. This patch fixes it by hashing the string contents instead to make the hashes reproduceable. 2021-07-14 Jakub Jelinek PR go/101407 * godump.c (godump_str_hash): New type. (godump_container::pot_dummy_types): Use string_hash instead of ptr_hash in the hash_set. (cherry picked from commit 3be762c2ed79e36b9c8faaea2be04725c967a34e)
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #6 from CVS Commits --- The releases/gcc-11 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:31b76a815fc177dd579adc03b671ba9a8846ae6c commit r11-8771-g31b76a815fc177dd579adc03b671ba9a8846ae6c Author: Jakub Jelinek Date: Wed Jul 14 10:22:50 2021 +0200 godump: Fix -fdump-go-spec= reproduceability issue [PR101407] pot_dummy_types is a hash_set from whose traversal the code prints some type lines. hash_set normally uses default_hash_traits which for pointer types (the hash set hashes const char *) uses pointer_hash which hashes the addresses of the pointers except of the least significant 3 bits. With address space randomization, that results in non-determinism in the -fdump-go-specs= generated file, each invocation can have different order of the lines emitted from pot_dummy_types traversal. This patch fixes it by hashing the string contents instead to make the hashes reproduceable. 2021-07-14 Jakub Jelinek PR go/101407 * godump.c (godump_str_hash): New type. (godump_container::pot_dummy_types): Use string_hash instead of ptr_hash in the hash_set. (cherry picked from commit 3be762c2ed79e36b9c8faaea2be04725c967a34e)
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #5 from CVS Commits --- The master branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:3be762c2ed79e36b9c8faaea2be04725c967a34e commit r12-2293-g3be762c2ed79e36b9c8faaea2be04725c967a34e Author: Jakub Jelinek Date: Wed Jul 14 10:22:50 2021 +0200 godump: Fix -fdump-go-spec= reproduceability issue [PR101407] pot_dummy_types is a hash_set from whose traversal the code prints some type lines. hash_set normally uses default_hash_traits which for pointer types (the hash set hashes const char *) uses pointer_hash which hashes the addresses of the pointers except of the least significant 3 bits. With address space randomization, that results in non-determinism in the -fdump-go-specs= generated file, each invocation can have different order of the lines emitted from pot_dummy_types traversal. This patch fixes it by hashing the string contents instead to make the hashes reproduceable. 2021-07-14 Jakub Jelinek PR go/101407 * godump.c (godump_str_hash): New type. (godump_container::pot_dummy_types): Use string_hash instead of ptr_hash in the hash_set.
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #4 from Toolybird --- Your patch solves the problem for me. Thank you very much!
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 Jakub Jelinek changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Assignee|ian at airs dot com|jakub at gcc dot gnu.org Ever confirmed|0 |1 Last reconfirmed||2021-07-12 --- Comment #3 from Jakub Jelinek --- Created attachment 51140 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51140=edit gcc12-pr101407.patch I can reproduce it. The problem is that hash_set for pointers by default uses ptr_hash, which hashes the pointer values rather than strings they point to, and that hash_set is then traversed and type lines are emitted during that traversal. So, with address space randomization the strings hash differently between different runs. This patch changes it to hash the strings instead and that should be reproduceable.
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #2 from Toolybird --- > Will try to bisect Well, that was a complete waste of time. There seems to an element of randomness to the problem. It turns out that GCC 10 is also affected as I was able to trigger it all the way back to basepoints/gcc-10 I give up for the moment. Hopefully someone who cares about binary reproducibility sees this, is able to replicate and fix.
[Bug go/101407] non-determinism in -fdump-go-spec
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101407 --- Comment #1 from Toolybird --- The bug is present on trunk. Will try to bisect...
