DavidSpickett added a comment. Hi @jansvoboda11 , we (Linaro) happen to be one of the few running a bot with threading disabled (for reasons that aren't important here). It has been red a lot lately so you won't have seen the report from it.
https://lab.llvm.org/buildbot/#/builders/178/builds/3045 This does not fail on our other bots and I think `LLVM_ENABLE_THREADS=OFF` is what breaks it. From a working build: $ /home/david.spickett/build-llvm-arm/bin/clang-scan-deps -compilation-database /home/david.spickett/build-llvm-arm-broken/tools/clang/test/ClangScanDeps/Output/modules-full-by-mod-name.cpp.tmp.cdb -j 4 -format experimental-full -mode preprocess-dependency-directives -module-name=header1 Building DependencyScanningWorker Building DependencyScanningWorker Building DependencyScanningWorker Building DependencyScanningWorker BaseFS was not null BaseFS was not null BaseFS moved BaseFS moved From a build with no threading: $ /home/david.spickett/build-llvm-arm-broken/bin/clang-scan-deps -compilation-database /home/david.spickett/build-llvm-arm-broken/tools/clang/test/ClangScanDeps/Output/modules-full-by-mod-name.cpp.tmp.cdb -j 4 -format experimental-full -mode preprocess-dependency-directives -module-name=header1 Building DependencyScanningWorker BaseFS was not null BaseFS moved clang-scan-deps: /home/david.spickett/llvm-project/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp:393: bool clang::tooling::dependencies::DependencyScanningWorker::computeDependencies(llvm::StringRef, const std::vector<std::string> &, clang::tooling::dependencies::DependencyConsumer &, clang::DiagnosticConsumer &, llvm::Optional<StringRef>): Assertion `BaseFS' failed. PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace. Stack dump: 0. Program arguments: /home/david.spickett/build-llvm-arm-broken/bin/clang-scan-deps -compilation-database /home/david.spickett/build-llvm-arm-broken/tools/clang/test/ClangScanDeps/Output/modules-full-by-mod-name.cpp.tmp.cdb -j 4 -format experimental-full -mode preprocess-dependency-directives -module-name=header1 Aborted (core dumped) I think I narrowed it down to the move you added (I put a comment on it). When threading is enabled 4 workers are made and so no one tries to use `BaseFs` after it has been moved from. When only one worker is made, it attempts to use after move `BaseFs`. In fact, if you give `-j 1` to the threaded version, it also crashes: $ /home/david.spickett/build-llvm-arm/bin/clang-scan-deps -compilation-database /home/david.spickett/build-llvm-arm-broken/tools/clang/test/Cla ngScanDeps/Output/modules-full-by-mod-name.cpp.tmp.cdb -j 1 -format experimental-full -mode preprocess-dependency-directives -module-name=header1 Building DependencyScanningWorker BaseFS was not null BaseFS moved clang-scan-deps: /home/david.spickett/llvm-project/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp:393: bool clang::tooling::dependencies::DependencyScanningWorker::computeDependencies(llvm::StringRef, const std::vector<std::string> &, clang::tooling::dependencies::DependencyConsumer &, clang::DiagnosticConsumer &, llvm::Optional<StringRef>): Assertion `BaseFS' failed. PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace. Aborted (core dumped) I think the same sort of thing would happen if you said `-j N+1` when you had N cores? One worker would be run twice? I'm not up on all the details. So yeah, to reproduce build without threading or add `-j 1`. Do you have an idea how this might be handled? If you are moving you clearly want to transfer ownership, but I'm not sure if the `BaseFs` can just be rebuilt each time. I suppose if N workers can each have a `BaseFs`, a single worker could recreate it as needed. Let me know what you think there. ================ Comment at: clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp:401 + auto OverlayFS = llvm::makeIntrusiveRefCnt<llvm::vfs::OverlayFileSystem>( + std::move(BaseFS)); + auto InMemoryFS = ---------------- This move seems like a problem when only one worker is made. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D135414/new/ https://reviews.llvm.org/D135414 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
