[clang] [llvm] [llvm][clang] Allocate a new stack instead of spawning a new thread to get more stack space (PR #133173)

Tue Apr 15 13:25:09 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-linux-multistage` running on `ppc64le-clang-multistage-test` while building `clang,llvm` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/76/builds/8770

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (ninja check 1) failure: stage 1 checked (failure)
...
[8/16] Generating exported symbols for clang_rt.asan-powerpc64le
[9/16] Generating exported symbols for clang_rt.msan-powerpc64le
[10/16] Generating version list for clang_rt.asan-dynamic-powerpc64le
[11/16] Generating exported symbols for clang_rt.tsan-powerpc64le
[12/16] Building CXX object compiler-rt/lib/ubsan/CMakeFiles/RTUbsan_dynamic_version_script_dummy.powerpc64le.dir/dummy.cpp.o
[13/16] Building CXX object compiler-rt/lib/asan/CMakeFiles/RTAsan_dynamic_version_script_dummy.powerpc64le.dir/dummy.cpp.o
[14/16] Linking CXX shared library /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/lib/clang/21/lib/powerpc64le-unknown-linux-gnu/libclang_rt.ubsan_standalone.so
[15/16] Generating /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/compile_commands.json
[16/16] Linking CXX shared library /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/lib/clang/21/lib/powerpc64le-unknown-linux-gnu/libclang_rt.asan.so
[643/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o
FAILED: unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o 
ccache /usr/lib64/ccache/c++ -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_STATIC -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/unittests/Support -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/unittests/Support -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/third-party/unittest/googletest/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/third-party/unittest/googlemock/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=c++17  -Wno-dangling-else -Wno-variadic-macros -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -Wno-suggest-override -MD -MT unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o -MF unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o.d -o unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o -c /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/unittests/Support/ProgramStackTest.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/unittests/Support/ProgramStackTest.cpp: In member function ‘virtual void ProgramStackTest_runOnNewStack_Test::TestBody()’:
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/unittests/Support/ProgramStackTest.cpp:33:55: error: call of overloaded ‘runOnNewStack(int, llvm::function_ref<void(int&)>, int&)’ is ambiguous
   runOnNewStack(0, function_ref<void(int &)>(func2), A);
                                                       ^
In file included from /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/unittests/Support/ProgramStackTest.cpp:9:
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/include/llvm/Support/ProgramStack.h:48:3: note: candidate: ‘R llvm::runOnNewStack(unsigned int, llvm::function_ref<Ret(Params ...)>, Ts&& ...) [with R = void; Ts = {int&}]’
 R runOnNewStack(unsigned StackSize, function_ref<R(Ts...)> Fn, Ts &&...Args) {
   ^~~~~~~~~~~~~
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/include/llvm/Support/ProgramStack.h:55:6: note: candidate: ‘void llvm::runOnNewStack(unsigned int, llvm::function_ref<void(Ts ...)>, Ts&& ...) [with Ts = {int&}]’
 void runOnNewStack(unsigned StackSize, function_ref<void(Ts...)> Fn,
      ^~~~~~~~~~~~~
[665/1225] Linking CXX executable tools/clang/unittests/ASTMatchers/ASTMatchersTests
[667/1225] Building CXX object unittests/ADT/CMakeFiles/ADTTests.dir/APSIntTest.cpp.o
[668/1225] Building CXX object unittests/ADT/CMakeFiles/ADTTests.dir/CombinationGeneratorTest.cpp.o
[669/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/raw_fd_stream_test.cpp.o
[670/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/xxhashTest.cpp.o
[671/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/TimerTest.cpp.o
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[674/1225] Building CXX object unittests/BinaryFormat/CMakeFiles/BinaryFormatTests.dir/TestFileMagic.cpp.o
[675/1225] Building CXX object unittests/MC/CMakeFiles/MCTests.dir/MCDisassemblerTest.cpp.o
[676/1225] Building CXX object unittests/Frontend/CMakeFiles/LLVMFrontendTests.dir/OpenMPCompositionTest.cpp.o
[677/1225] Building CXX object tools/clang/tools/extra/clangd/unittests/CMakeFiles/ClangdTests.dir/support/ContextTests.cpp.o
[678/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/TrailingObjectsTest.cpp.o
[679/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/IndexedAccessorTest.cpp.o
[680/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ReverseIterationTest.cpp.o
[681/1225] Building CXX object unittests/Target/CMakeFiles/TargetMachineCTests.dir/TargetMachineOptionsTest.cpp.o
[682/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ErrorOrTest.cpp.o
[683/1225] Building CXX object unittests/MC/CMakeFiles/MCTests.dir/TargetRegistry.cpp.o
[684/1225] Building CXX object unittests/Transforms/Utils/CMakeFiles/UtilsTests.dir/ScalarEvolutionExpanderTest.cpp.o
[685/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/BlockFrequencyTest.cpp.o
[686/1225] Building CXX object tools/clang/tools/extra/clangd/unittests/CMakeFiles/ClangdTests.dir/TestFS.cpp.o
[687/1225] Building CXX object unittests/ADT/CMakeFiles/ADTTests.dir/IntrusiveRefCntPtrTest.cpp.o
[688/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/PerThreadBumpPtrAllocatorTest.cpp.o
[689/1225] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/DivisionByConstantTest.cpp.o
[690/1225] Building CXX object unittests/ADT/CMakeFiles/ADTTests.dir/StringSetTest.cpp.o
[691/1225] Building CXX object unittests/ADT/CMakeFiles/ADTTests.dir/APFixedPointTest.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/133173