RESOLVED FIXED247622
Avoid using __TIMESTAMP__ when building for a compilation cache 
https://bugs.webkit.org/show_bug.cgi?id=247622
Summary Avoid using __TIMESTAMP__ when building for a compilation cache
Elliott Williams
Reported 2022-11-08 08:37:03 PST
__TIME__, __DATE__, and __TIMESTAMP__ are non-deterministic and interfere with cache reproducibility.
Attachments
Add attachment proposed patch, testcase, etc.
Elliott Williams
Comment 1 2022-11-08 08:54:39 PST
<rdar://problem/102056857>
Elliott Williams
Comment 2 2022-11-08 08:54:54 PST
Pull request: https://github.com/WebKit/WebKit/pull/6256
EWS
Comment 3 2022-11-17 17:46:37 PST
Committed 256816@main (adb96155be5e): <https://commits.webkit.org/256816@main> Reviewed commits have been landed. Closing PR #6256 and removing active labels.
Alexander Kanavin
Comment 4 2023-06-26 03:09:34 PDT
This actually broke reproducibility of cmake-based builds, as (non-reproducible) TIMESTAMP is now injected into binaries where this previously did not happen (look at the changes to CMakeLists.txt in the PR linked to this ticket).
Elliott Williams
Comment 5 2023-06-26 11:05:36 PDT
> This actually broke reproducibility of cmake-based builds, as (non-reproducible) TIMESTAMP is now injected into binaries where this previously did not happen How was it reproducible before? We used to call `jscBytecodeCacheVersion()` in all builds, which was based on __TIMESTAMP__. My intention was to maintain the status quo for cmake builds, since the checksum-based approach did not seem to be easily compatible with cmake's ninja generator.
Michael Catanzaro
Comment 6 2023-06-26 13:57:17 PDT
(In reply to Elliott Williams from comment #5) > How was it reproducible before? __TIMESTAMP__ is the file modification time, which was previously fixed but now changes on every build. See bug #252308 and bug #258517.
Note You need to log in before you can comment on or make changes to this bug.