[MLIR] Some tools combine dylib and static component libs (link errors on Windows, random misbehavior on Linux)

[andrurogerz]

Overview

When configured to build as a Windows DLL, LLVM does not build successfully when the mlir project is included.

LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: static class llvm::ErrorOr<class std::unique_ptr<class llvm::MemoryBuffer,struct std::default_delete<class llvm::MemoryBuffer> > > __cdecl llvm::MemoryBuffer::getFileOrSTDIN(class llvm::Twine const &,bool,bool,class std::optional<struct llvm::Align>)" (?getFileOrSTDIN@MemoryBuffer@llvm@@SA?AV?$ErrorOr@V?$unique_ptr@VMemoryBuffer@llvm@@U?$default_delete@VMemoryBuffer@llvm@@@std@@@std@@@2@AEBVTwine@2@_N1V?$optional@UAlign@llvm@@@std@@@Z) already defined in LLVMSupport.lib(MemoryBuffer.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::CleanupInstaller::~CleanupInstaller(void)" (??1CleanupInstaller@llvm@@QEAA@XZ) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::ToolOutputFile::ToolOutputFile(class llvm::StringRef,class std::error_code &,enum llvm::sys::fs::OpenFlags)" (??0ToolOutputFile@llvm@@QEAA@VStringRef@1@AEAVerror_code@std@@W4OpenFlags@fs@sys@1@@Z) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)

The duplicate symbols are exported by the LLVM DLL and by a static library linked as a transitive dependency.

Repro

On Windows 11:

git checkout 25d1285eecbab731eaf418c8aab44e4eb5f9e538

cmake -B build -S llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;llvm;mlir" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_BUILD_TESTS=ON -DLLVM_BUILD_EXAMPLES=ON -DCMAKE_BUILD_TYPE=Release  -DCLANG_LINK_CLANG_DYLIB=OFF -DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB_VIS=ON -DLLVM_LINK_LLVM_DYLIB=ON

ninja -C build

Observe build errors.

C:\WINDOWS\system32\cmd.exe /C "cd . && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests  -- C:\PROGRA~1\MICROS~4\2022\COMMUN~1\VC\Tools\MSVC\1439~1.335\bin\HostX64\x64\link.exe /nologo tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\mlir-src-sharder.cpp.obj tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\S_\llvm\llvm-project\llvm\resources\windows_version_resource.rc.res  /out:bin\mlir-src-sharder.exe /implib:lib\mlir-src-sharder.lib /pdb:bin\mlir-src-sharder.pdb /version:0.0 /machine:x64 /STACK:10000000 /INCREMENTAL:NO /subsystem:console  lib\LLVMSupport.lib  lib\LLVMTableGen.lib  lib\MLIRSupport.lib  psapi.lib  shell32.lib  ole32.lib  uuid.lib  advapi32.lib  ws2_32.lib  ntdll.lib  delayimp.lib  -delayload:shell32.dll  -delayload:ole32.dll  lib\LLVMDemangle.lib  lib\LLVM-22git.lib  kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
LINK: command "C:\PROGRA~1\MICROS~4\2022\COMMUN~1\VC\Tools\MSVC\1439~1.335\bin\HostX64\x64\link.exe /nologo tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\mlir-src-sharder.cpp.obj tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\S_\llvm\llvm-project\llvm\resources\windows_version_resource.rc.res /out:bin\mlir-src-sharder.exe /implib:lib\mlir-src-sharder.lib /pdb:bin\mlir-src-sharder.pdb /version:0.0 /machine:x64 /STACK:10000000 /INCREMENTAL:NO /subsystem:console lib\LLVMSupport.lib lib\LLVMTableGen.lib lib\MLIRSupport.lib psapi.lib shell32.lib ole32.lib uuid.lib advapi32.lib ws2_32.lib ntdll.lib delayimp.lib -delayload:shell32.dll -delayload:ole32.dll lib\LLVMDemangle.lib lib\LLVM-22git.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST:EMBED,ID=1" failed (exit code 1169) with the following output:
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: static class llvm::ErrorOr<class std::unique_ptr<class llvm::MemoryBuffer,struct std::default_delete<class llvm::MemoryBuffer> > > __cdecl llvm::MemoryBuffer::getFileOrSTDIN(class llvm::Twine const &,bool,bool,class std::optional<struct llvm::Align>)" (?getFileOrSTDIN@MemoryBuffer@llvm@@SA?AV?$ErrorOr@V?$unique_ptr@VMemoryBuffer@llvm@@U?$default_delete@VMemoryBuffer@llvm@@@std@@@std@@@2@AEBVTwine@2@_N1V?$optional@UAlign@llvm@@@std@@@Z) already defined in LLVMSupport.lib(MemoryBuffer.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::CleanupInstaller::~CleanupInstaller(void)" (??1CleanupInstaller@llvm@@QEAA@XZ) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::ToolOutputFile::ToolOutputFile(class llvm::StringRef,class std::error_code &,enum llvm::sys::fs::OpenFlags)" (??0ToolOutputFile@llvm@@QEAA@VStringRef@1@AEAVerror_code@std@@W4OpenFlags@fs@sys@1@@Z) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
   Creating library lib\mlir-src-sharder.lib and object lib\mlir-src-sharder.exp
bin\mlir-src-sharder.exe : fatal error LNK1169: one or more multiply defined symbols found

[llvmbot]

@llvm/issue-subscribers-mlir

Author: Andrew Rogers (andrurogerz)

## Overview When configured to build as a Windows DLL, LLVM does not build successfully when the `mlir` project is included.

LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: static class llvm::ErrorOr&lt;class std::unique_ptr&lt;class llvm::MemoryBuffer,struct std::default_delete&lt;class llvm::MemoryBuffer&gt; &gt; &gt; __cdecl llvm::MemoryBuffer::getFileOrSTDIN(class llvm::Twine const &amp;,bool,bool,class std::optional&lt;struct llvm::Align&gt;)" (?getFileOrSTDIN@<!-- -->MemoryBuffer@<!-- -->llvm@@<!-- -->SA?AV?$ErrorOr@<!-- -->V?$unique_ptr@<!-- -->VMemoryBuffer@<!-- -->llvm@@<!-- -->U?$default_delete@<!-- -->VMemoryBuffer@<!-- -->llvm@@@<!-- -->std@@@<!-- -->std@@@<!-- -->2@<!-- -->AEBVTwine@<!-- -->2@<!-- -->_N1V?$optional@<!-- -->UAlign@<!-- -->llvm@@@<!-- -->std@@@<!-- -->Z) already defined in LLVMSupport.lib(MemoryBuffer.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::CleanupInstaller::~CleanupInstaller(void)" (??1CleanupInstaller@<!-- -->llvm@@<!-- -->QEAA@<!-- -->XZ) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::ToolOutputFile::ToolOutputFile(class llvm::StringRef,class std::error_code &amp;,enum llvm::sys::fs::OpenFlags)" (??0ToolOutputFile@<!-- -->llvm@@<!-- -->QEAA@<!-- -->VStringRef@<!-- -->1@<!-- -->AEAVerror_code@<!-- -->std@@<!-- -->W4OpenFlags@<!-- -->fs@<!-- -->sys@<!-- -->1@@<!-- -->Z) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)

The duplicate symbols are exported by the LLVM DLL and by a static library linked as a transitive dependency.

Repro

On Windows 11:

git checkout 66d1c37eb69c8ab38af6e61a38b7605f5f05d75b

cmake -B build -S llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;llvm;mlir" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_BUILD_TESTS=ON -DLLVM_BUILD_EXAMPLES=ON -DCMAKE_BUILD_TYPE=Release  -DCLANG_LINK_CLANG_DYLIB=OFF -DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB_VIS=ON -DLLVM_LINK_LLVM_DYLIB=ON

ninja -C build

Observe build errors.

C:\WINDOWS\system32\cmd.exe /C "cd . && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests  -- C:\PROGRA~1\MICROS~4\2022\COMMUN~1\VC\Tools\MSVC\1439~1.335\bin\HostX64\x64\link.exe /nologo tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\mlir-src-sharder.cpp.obj tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\S_\llvm\llvm-project\llvm\resources\windows_version_resource.rc.res  /out:bin\mlir-src-sharder.exe /implib:lib\mlir-src-sharder.lib /pdb:bin\mlir-src-sharder.pdb /version:0.0 /machine:x64 /STACK:10000000 /INCREMENTAL:NO /subsystem:console  lib\LLVMSupport.lib  lib\LLVMTableGen.lib  lib\MLIRSupport.lib  psapi.lib  shell32.lib  ole32.lib  uuid.lib  advapi32.lib  ws2_32.lib  ntdll.lib  delayimp.lib  -delayload:shell32.dll  -delayload:ole32.dll  lib\LLVMDemangle.lib  lib\LLVM-22git.lib  kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
LINK: command "C:\PROGRA~1\MICROS~4\2022\COMMUN~1\VC\Tools\MSVC\1439~1.335\bin\HostX64\x64\link.exe /nologo tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\mlir-src-sharder.cpp.obj tools\mlir\tools\mlir-src-sharder\CMakeFiles\mlir-src-sharder.dir\S_\llvm\llvm-project\llvm\resources\windows_version_resource.rc.res /out:bin\mlir-src-sharder.exe /implib:lib\mlir-src-sharder.lib /pdb:bin\mlir-src-sharder.pdb /version:0.0 /machine:x64 /STACK:10000000 /INCREMENTAL:NO /subsystem:console lib\LLVMSupport.lib lib\LLVMTableGen.lib lib\MLIRSupport.lib psapi.lib shell32.lib ole32.lib uuid.lib advapi32.lib ws2_32.lib ntdll.lib delayimp.lib -delayload:shell32.dll -delayload:ole32.dll lib\LLVMDemangle.lib lib\LLVM-22git.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST:EMBED,ID=1" failed (exit code 1169) with the following output:
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: static class llvm::ErrorOr&lt;class std::unique_ptr&lt;class llvm::MemoryBuffer,struct std::default_delete&lt;class llvm::MemoryBuffer&gt; &gt; &gt; __cdecl llvm::MemoryBuffer::getFileOrSTDIN(class llvm::Twine const &amp;,bool,bool,class std::optional&lt;struct llvm::Align&gt;)" (?getFileOrSTDIN@<!-- -->MemoryBuffer@<!-- -->llvm@@<!-- -->SA?AV?$ErrorOr@<!-- -->V?$unique_ptr@<!-- -->VMemoryBuffer@<!-- -->llvm@@<!-- -->U?$default_delete@<!-- -->VMemoryBuffer@<!-- -->llvm@@@<!-- -->std@@@<!-- -->std@@@<!-- -->2@<!-- -->AEBVTwine@<!-- -->2@<!-- -->_N1V?$optional@<!-- -->UAlign@<!-- -->llvm@@@<!-- -->std@@@<!-- -->Z) already defined in LLVMSupport.lib(MemoryBuffer.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::CleanupInstaller::~CleanupInstaller(void)" (??1CleanupInstaller@<!-- -->llvm@@<!-- -->QEAA@<!-- -->XZ) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
LLVM-22git.lib(LLVM-22git.dll) : error LNK2005: "public: __cdecl llvm::ToolOutputFile::ToolOutputFile(class llvm::StringRef,class std::error_code &amp;,enum llvm::sys::fs::OpenFlags)" (??0ToolOutputFile@<!-- -->llvm@@<!-- -->QEAA@<!-- -->VStringRef@<!-- -->1@<!-- -->AEAVerror_code@<!-- -->std@@<!-- -->W4OpenFlags@<!-- -->fs@<!-- -->sys@<!-- -->1@@<!-- -->Z) already defined in LLVMSupport.lib(ToolOutputFile.cpp.obj)
   Creating library lib\mlir-src-sharder.lib and object lib\mlir-src-sharder.exp
bin\mlir-src-sharder.exe : fatal error LNK1169: one or more multiply defined symbols found

[mgorny]

I've noticed this very problem while debugging #157885 (comment). While this kind of linking is not an error on Linux (I really think it should be), it is likely to cause random issues at runtime.

FWICS it affects multiple tools (found via simple grep, so possibly incomplete):

bin/mlir-pdll
bin/mlir-pdll-lsp-server
bin/mlir-src-sharder
bin/tblgen-lsp-server
bin/tblgen-to-irdl

[mgorny]

…and the problem stems from MLIRPDLLParser using DISABLE_LLVM_LINK_LLVM_DYLIB which implies that this library must not be used in anything that links to dylib. And that seems to stem from the fact that it uses TableGen bits which really shouldn't be used by anything but tablegens, which are lightweight standalone tools used only at build time. The whole problem seems to be present since day one, and I don't see any easy way to fix it, short of some major redesign to fix layering violations.