Keep exports_filter libraries linked in cc_shared_library#694
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cameron-martin wants to merge 8 commits intobazelbuild:mainfrom
Open
Keep exports_filter libraries linked in cc_shared_library#694cameron-martin wants to merge 8 commits intobazelbuild:mainfrom
cameron-martin wants to merge 8 commits intobazelbuild:mainfrom
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Libraries claimed via exports_filter are expected to be provided by the producing cc_shared_library even when they are otherwise unused by that shared library's own objects. Without special handling they can still be wrapped in start-lib/end-lib and dropped by the linker, which breaks downstream shared libraries that rely on those exported symbols through dynamic_deps. Treat libraries matched by exports_filter like other top-level static link inputs for this purpose and wrap them as alwayslink before linking. Add a regression test that covers an exported transitive library used only by a downstream cc_shared_library through dynamic_deps.
cameron-martin
requested review from
c-mita,
pzembrod and
trybka
as code owners
lilygorsheneva
previously approved these changes
Apr 20, 2026
Collaborator
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Tests fail on Bazel 7/8, you should disable them |
Author
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Why do they fail on Bazel 7/8? Is it because they use a version of cc_shared_library that is shipped with Bazel? |
Collaborator
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Yes. |
Author
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I've used the example in tests/alwayslink_srcs/BUILD |
Author
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I attempted to fix this test on windows too but I don't really know enough about how linking & shared libraries on windows works, so is it okay to leave the test nix-only? |
Collaborator
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I'm not sure to what extent we care about that (I know we have a lot of tests disabled for windows but I assumed the underlying feature doesn't work there); @trybka ? |
Collaborator
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Trybka doesn't know, what about @fmeum ? |
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Libraries exposed via exports_filter are expected to be provided by the producing cc_shared_library even when they are otherwise unused by that shared library's own objects. Without special handling they can still be wrapped in start-lib/end-lib and dropped by the linker, which breaks downstream shared libraries that rely on those exported symbols through dynamic_deps.
Any libraries covered by exports_filter are now treated as alwayslink, to avoid this issue.
Fixes bazelbuild/bazel#20428