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

Tue Apr 15 11:51:12 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-cmake-x86_64-avx512-linux` running on `avx512-intel64` while building `clang,llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/133/builds/14559

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

```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
...
[778/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/GenericDomTreeTest.cpp.o
[779/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ManagedStatic.cpp.o
[780/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/InstructionCostTest.cpp.o
[781/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ModRefTest.cpp.o
[782/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/MemoryBufferRefTest.cpp.o
[783/1011] Building CXX object unittests/IR/CMakeFiles/IRTests.dir/ConstantRangeTest.cpp.o
[784/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/MD5Test.cpp.o
[785/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/FileOutputBufferTest.cpp.o
[786/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/OptimizedStructLayoutTest.cpp.o
[787/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o
FAILED: unittests/Support/CMakeFiles/SupportTests.dir/ProgramStackTest.cpp.o 
/usr/bin/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/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/unittests/Support -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/unittests/Support -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/third-party/unittest/googletest/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/third-party/unittest/googlemock/include -march=cascadelake -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-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -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 /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/unittests/Support/ProgramStackTest.cpp
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/unittests/Support/ProgramStackTest.cpp: In member function ‘virtual void ProgramStackTest_runOnNewStack_Test::TestBody()’:
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/unittests/Support/ProgramStackTest.cpp:33:16: error: call of overloaded ‘runOnNewStack(int, llvm::function_ref<void(int&)>, int&)’ is ambiguous
   33 |   runOnNewStack(0, function_ref<void(int &)>(func2), A);
      |   ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/unittests/Support/ProgramStackTest.cpp:9:
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/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&}]’
   48 | R runOnNewStack(unsigned StackSize, function_ref<R(Ts...)> Fn, Ts &&...Args) {
      |   ^~~~~~~~~~~~~
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/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&}]’
   55 | void runOnNewStack(unsigned StackSize, function_ref<void(Ts...)> Fn,
      |      ^~~~~~~~~~~~~
[788/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/PerThreadBumpPtrAllocatorTest.cpp.o
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[793/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ProcessTest.cpp.o
[794/1011] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ReverseIterationTest.cpp.o
[795/1011] Linking CXX executable unittests/MI/MITests
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[813/1011] Linking CXX executable unittests/ExecutionEngine/Orc/OrcJITTests

```

</details>

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