[llvm] [CAS] Add MappedFileRegionArena (PR #114099)

Mon Sep 15 10:24:51 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `openmp-offload-sles-build-only` running on `rocm-worker-hw-04-sles` while building `llvm` at step 5 "compile-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/140/builds/30748

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

```
Step 5 (compile-openmp) failure: build (failure)
...
4.239 [7130/32/247] Building CXX object utils/PerfectShuffle/CMakeFiles/llvm-PerfectShuffle.dir/PerfectShuffle.cpp.o
4.243 [7129/32/248] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/MergingTypeTableBuilder.cpp.o
4.250 [7128/32/249] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/SimpleTypeSerializer.cpp.o
4.252 [7127/32/250] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/StringsAndChecksums.cpp.o
4.252 [7126/32/251] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/RecordSerialization.cpp.o
4.255 [7125/32/252] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/RecordName.cpp.o
4.264 [7124/32/253] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/SymbolRecordMapping.cpp.o
4.264 [7123/32/254] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/SymbolRecordHelpers.cpp.o
4.272 [7122/32/255] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/SymbolSerializer.cpp.o
4.282 [7121/32/256] Building CXX object lib/CAS/CMakeFiles/LLVMCAS.dir/MappedFileRegionArena.cpp.o
FAILED: lib/CAS/CMakeFiles/LLVMCAS.dir/MappedFileRegionArena.cpp.o 
ccache /usr/bin/c++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Ilib/CAS -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS -Iinclude -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/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-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++1z -MD -MT lib/CAS/CMakeFiles/LLVMCAS.dir/MappedFileRegionArena.cpp.o -MF lib/CAS/CMakeFiles/LLVMCAS.dir/MappedFileRegionArena.cpp.o.d -o lib/CAS/CMakeFiles/LLVMCAS.dir/MappedFileRegionArena.cpp.o -c /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS/MappedFileRegionArena.cpp
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS/MappedFileRegionArena.cpp: In static member function ‘static llvm::Expected<llvm::cas::MappedFileRegionArena> llvm::cas::MappedFileRegionArena::create(const llvm::Twine&, uint64_t, uint64_t, llvm::function_ref<llvm::Error(llvm::cas::MappedFileRegionArena&)>)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS/MappedFileRegionArena.cpp:275:10: error: could not convert ‘Result’ from ‘llvm::cas::MappedFileRegionArena’ to ‘llvm::Expected<llvm::cas::MappedFileRegionArena>’
   return Result;
          ^~~~~~
4.286 [7121/31/257] Creating export file for LTO
4.302 [7121/30/258] Linking CXX executable bin/llvm-PerfectShuffle
4.304 [7121/29/259] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeIndexDiscovery.cpp.o
4.309 [7121/28/260] Building CXX object lib/CAS/CMakeFiles/LLVMCAS.dir/BuiltinCAS.cpp.o
4.322 [7121/27/261] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/SymbolDumper.cpp.o
4.342 [7121/26/262] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeDumpVisitor.cpp.o
4.347 [7121/25/263] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeHashing.cpp.o
4.349 [7121/24/264] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeIndex.cpp.o
4.428 [7121/23/265] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeRecordHelpers.cpp.o
4.432 [7121/22/266] Building CXX object lib/LineEditor/CMakeFiles/LLVMLineEditor.dir/LineEditor.cpp.o
4.450 [7121/21/267] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeTableCollection.cpp.o
4.450 [7121/20/268] Building CXX object lib/CAS/CMakeFiles/LLVMCAS.dir/InMemoryCAS.cpp.o
4.454 [7121/19/269] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeStreamMerger.cpp.o
4.462 [7121/18/270] Building CXX object lib/Telemetry/CMakeFiles/LLVMTelemetry.dir/Telemetry.cpp.o
4.463 [7121/17/271] Building CXX object lib/WindowsManifest/CMakeFiles/LLVMWindowsManifest.dir/WindowsManifestMerger.cpp.o
4.471 [7121/16/272] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeRecordMapping.cpp.o
4.502 [7121/15/273] Building CXX object utils/UnicodeData/CMakeFiles/UnicodeNameMappingGenerator.dir/UnicodeNameMappingGenerator.cpp.o
4.523 [7121/14/274] Building CXX object lib/CAS/CMakeFiles/LLVMCAS.dir/ObjectStore.cpp.o
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS/ObjectStore.cpp: In member function ‘llvm::Error llvm::cas::ObjectStore::validateTree(llvm::cas::ObjectRef)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/CAS/ObjectStore.cpp:141:22: warning: unused variable ‘I’ [-Wunused-variable]
     auto [I, Inserted] = ValidatedRefs.insert(Ref);
                      ^
4.532 [7121/13/275] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/Signals.cpp.o
4.538 [7121/12/276] Building CXX object utils/llvm-test-mustache-spec/CMakeFiles/llvm-test-mustache-spec.dir/llvm-test-mustache-spec.cpp.o
4.571 [7121/11/277] Building CXX object tools/flang/unittests/Evaluate/CMakeFiles/leading-zero-bit-count.test.dir/leading-zero-bit-count.cpp.o
4.588 [7121/10/278] Building CXX object third-party/unittest/CMakeFiles/llvm_gtest.dir/googlemock/src/gmock-all.cc.o
4.592 [7121/9/279] Building CXX object third-party/unittest/UnitTestMain/CMakeFiles/llvm_gtest_main.dir/TestMain.cpp.o
4.603 [7121/8/280] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/Path.cpp.o
4.604 [7121/7/281] Building CXX object third-party/unittest/CMakeFiles/llvm_gtest.dir/googletest/src/gtest-all.cc.o
4.942 [7121/6/282] Building CXX object lib/TableGen/CMakeFiles/LLVMTableGen.dir/Main.cpp.o
4.994 [7121/5/283] Building CXX object utils/not/CMakeFiles/not.dir/not.cpp.o
5.382 [7121/4/284] Building CXX object utils/split-file/CMakeFiles/split-file.dir/split-file.cpp.o
5.446 [7121/3/285] Building CXX object utils/yaml-bench/CMakeFiles/yaml-bench.dir/YAMLBench.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/114099