Fix cache collision with object file and precompiled headers#2268
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sylvestre merged 1 commit intomozilla:mainfrom Oct 5, 2024
Merged
Fix cache collision with object file and precompiled headers#2268sylvestre merged 1 commit intomozilla:mainfrom
sylvestre merged 1 commit intomozilla:mainfrom
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When compiling with PCH enabled, it happens that some times object files end up with PCH content, or that .gch files end up with object code. Simplest way to reproduce the problem: $ touch empty.c $ gcc -c -o out1 empty.c $ gcc -x c-header -c -o out2 empty.c $ file out1 out2 out1: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped out2: GCC precompiled header (version 014) for C The two files are different. But if we feed these compilations to sccache, they lead to the same result: $ sccache gcc -c -o out3 empty.c $ sccache gcc -x c-header -c -o out4 empty.c $ file out3 out4 out3: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped out4: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped Same thing is reproducible with c++ compiler and -x c++-header argument. The reason is that the hash string that identifies each command line is the same. With this patch, compilation of C files is always differentiated from compilations of same C-Header files. And compilation of C++ files is always differentiated from compilations of same C++-Header files. Fixes mozilla#1851.
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Contributor
Author
|
This is ready for review. The weirdest thing happened while I was running the integration tests on my fork: The "clang" integration test failed (the last |
Collaborator
yes, the cache might be full at time |
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #2268 +/- ##
==========================================
+ Coverage 30.91% 40.61% +9.70%
==========================================
Files 53 54 +1
Lines 20112 20746 +634
Branches 9755 9641 -114
==========================================
+ Hits 6217 8427 +2210
- Misses 7922 8150 +228
+ Partials 5973 4169 -1804 ☔ View full report in Codecov by Sentry. |
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nice easy fix, well done :) |
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When compiling with PCH enabled, it happens that some times object files end up with PCH content, or that .gch files end up with object code.
Simplest way to reproduce the problem:
$ touch empty.c
$ gcc -c -o out1 empty.c
$ gcc -x c-header -c -o out2 empty.c
$ file out1 out2
out1: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped
out2: GCC precompiled header (version 014) for C
The two files are different. But if we feed these compilations to sccache, they lead to the same result:
$ sccache gcc -c -o out3 empty.c
$ sccache gcc -x c-header -c -o out4 empty.c
$ file out3 out4
out3: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped
out4: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped
Same thing is reproducible with c++ compiler and -x c++-header argument.
The reason is that the hash string that identifies each command line is the same.
With this patch, compilation of C files is always differentiated from compilations of same C-Header files. And compilation of C++ files is always differentiated from compilations of same C++-Header files.
Fixes #1851.