[CMake][Release] Disable PGO #88465
[CMake][Release] Disable PGO #88465
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Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors.
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@llvm/pr-subscribers-clang Author: Tom Stellard (tstellar) ChangesRunning the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run Full diff: https://github.com/llvm/llvm-project/pull/88465.diff 1 Files Affected:
diff --git a/clang/cmake/caches/Release.cmake b/clang/cmake/caches/Release.cmake
index 1ca9138b980731..bd1f688d61a7ea 100644
--- a/clang/cmake/caches/Release.cmake
+++ b/clang/cmake/caches/Release.cmake
@@ -4,7 +4,7 @@
# General Options
set(LLVM_RELEASE_ENABLE_LTO THIN CACHE STRING "")
-set(LLVM_RELEASE_ENABLE_PGO ON CACHE BOOL "")
+set(LLVM_RELEASE_ENABLE_PGO OFF CACHE BOOL "")
set(CMAKE_BUILD_TYPE RELEASE CACHE STRING "")
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LGTM.
I've run into the issue where profile data is generated again where it shouldn't be. I've meant to open up an issue and look into it at some point, but haven't had time to do so. I haven't previously run into this causing recompilations, but the outlined flow makes sense.
I'm assuming this is a stop-gap, and the plan is to eventually fix the issue and reenable PGO in the release cache?
Yes, I would like to fix this at some point, but not sure when I'll get to it. |
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/cherry-pick 0d2bb7f) |
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Failed to cherry-pick: 0d2bb7f) https://github.com/llvm/llvm-project/actions/runs/8668528827 Please manually backport the fix and push it to your github fork. Once this is done, please create a pull request |
Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors.
Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors. (cherry picked from commit 0d2bb7f)
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PR is here: #89000 |
Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors. (cherry picked from commit 0d2bb7f)
Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors. (cherry picked from commit 0d2bb7f)
Running the test-release.sh script with PGO enabled causes build errors like: ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run `ninja check-all` and then `ninja install` like we do in test-release.sh, then the profile data is regenerated during `ninja install` and some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors.
Running the test-release.sh script with PGO enabled causes build errors like:
ld.lld: error: Function Import: link error: linking module flags 'ProfileSummary': IDs have conflicting values
I believe this a build system bug due to the PGO profile data being generated unconditionally. If you run
ninja check-alland thenninja installlike we do in test-release.sh, then the profile data is regenerated duringninja installand some of the clang tools which are not test dependencies get build during the ninja install step with different profile data. When these tools link against the LLVM libraries, like libSupport, we end up with these errors.