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

Tue Apr 15 15:55:56 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-with-thin-lto-ubuntu` running on `as-worker-92` while building `clang,llvm` at step 6 "build-stage1-compiler".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/127/builds/3025

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

```
Step 6 (build-stage1-compiler) failure: build (failure)
...
934.144 [171/72/6308] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ModRefTest.cpp.o
934.159 [170/72/6309] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/MemoryBufferRefTest.cpp.o
934.195 [169/72/6310] Building CXX object unittests/IR/CMakeFiles/IRTests.dir/InstructionsTest.cpp.o
934.242 [168/72/6311] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/FileOutputBufferTest.cpp.o
934.277 [167/72/6312] Linking CXX executable tools/clang/unittests/AST/ASTTests
934.400 [166/72/6313] Building CXX object unittests/SandboxIR/CMakeFiles/SandboxIRTests.dir/PassTest.cpp.o
934.554 [165/72/6314] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/BalancedPartitioningTest.cpp.o
934.753 [164/72/6315] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/OptimizedStructLayoutTest.cpp.o
934.789 [163/72/6316] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/RecyclerTest.cpp.o
934.810 [162/72/6317] 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_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/unittests/Support -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/unittests/Support -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/include -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/include -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/third-party/unittest/googletest/include -I/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/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-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  -Wno-dangling-else -Wno-variadic-macros -fno-exceptions -funwind-tables -fno-rtti -Wno-suggest-override -std=c++17 -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/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/unittests/Support/ProgramStackTest.cpp
/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/unittests/Support/ProgramStackTest.cpp: In member function ‘virtual void ProgramStackTest_runOnNewStack_Test::TestBody()’:
/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/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 /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/unittests/Support/ProgramStackTest.cpp:9:
/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/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) {
      |   ^~~~~~~~~~~~~
/home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/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,
      |      ^~~~~~~~~~~~~
934.852 [162/71/6318] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/LineIteratorTest.cpp.o
935.275 [162/70/6319] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/MatchersTest.cpp.o
935.336 [162/69/6320] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ReverseIterationTest.cpp.o
935.352 [162/68/6321] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/PerThreadBumpPtrAllocatorTest.cpp.o
935.391 [162/67/6322] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/SHA256.cpp.o
935.454 [162/66/6323] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ProcessTest.cpp.o
935.638 [162/65/6324] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/RISCVAttributeParserTest.cpp.o
935.639 [162/64/6325] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/NativeFormatTests.cpp.o
935.741 [162/63/6326] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/LockFileManagerTest.cpp.o
935.849 [162/62/6327] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/SipHashTest.cpp.o
935.901 [162/61/6328] Building CXX object unittests/ProfileData/CMakeFiles/ProfileDataTests.dir/SampleProfTest.cpp.o
935.998 [162/60/6329] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/ReplaceFileTest.cpp.o
936.191 [162/59/6330] Building CXX object unittests/SandboxIR/CMakeFiles/SandboxIRTests.dir/RegionTest.cpp.o
936.338 [162/58/6331] Building CXX object unittests/SandboxIR/CMakeFiles/SandboxIRTests.dir/UtilsTest.cpp.o
936.342 [162/57/6332] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/GlobPatternTest.cpp.o
936.384 [162/56/6333] Building CXX object unittests/Passes/Plugins/CMakeFiles/PluginsTests.dir/PluginsTest.cpp.o
936.534 [162/55/6334] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/SignalsTest.cpp.o
936.562 [162/54/6335] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/RegexTest.cpp.o
936.823 [162/53/6336] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/TypeNameTest.cpp.o
936.888 [162/52/6337] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/DataExtractorTest.cpp.o
937.014 [162/51/6338] Linking CXX executable unittests/ExecutionEngine/Orc/OrcJITTests
937.017 [162/50/6339] Linking CXX executable unittests/CodeGen/CodeGenTests
937.033 [162/49/6340] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/SwapByteOrderTest.cpp.o
937.097 [162/48/6341] Building CXX object unittests/Object/CMakeFiles/ObjectTests.dir/ELFObjectFileTest.cpp.o
937.181 [162/47/6342] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/FileCollectorTest.cpp.o
937.200 [162/46/6343] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/BinaryStreamTest.cpp.o

```

</details>

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