[PATCH] D12488: Enable linking tools, shared libraries against libLLVM

Wed Sep 2 10:56:42 PDT 2015

beanz added a comment.

Clang builds, but it doesn’t link libLLVM. See:

  > grep "build bin/clang-3.8" ./build.ninja
  build bin/clang-3.8: CXX_EXECUTABLE_LINKER__clang tools/clang/tools/driver/CMakeFiles/clang.dir/driver.cpp.o tools/clang/tools/driver/CMakeFiles/clang.dir/cc1_main.cpp.o tools/clang/tools/driver/CMakeFiles/clang.dir/cc1as_main.cpp.o | lib/libLLVM.3.8.0svn.dylib lib/libclangBasic.a lib/libclangCodeGen.a lib/libclangDriver.a lib/libclangFrontend.a lib/libclangFrontendTool.a lib/libclangCodeGen.a lib/libLLVMBitWriter.a lib/libLLVMipo.a lib/libLLVMVectorize.a lib/libLLVMIRReader.a lib/libLLVMAsmParser.a lib/libLLVMInstrumentation.a lib/libLLVMLinker.a lib/libLLVMObjCARCOpts.a lib/libLLVMProfileData.a lib/libLLVMObject.a lib/libLLVMScalarOpts.a lib/libLLVMInstCombine.a lib/libLLVMTarget.a lib/libLLVMTransformUtils.a lib/libLLVMAnalysis.a lib/libclangRewriteFrontend.a lib/libclangARCMigrate.a lib/libclangStaticAnalyzerFrontend.a lib/libclangFrontend.a lib/libclangDriver.a lib/libLLVMOption.a lib/libclangParse.a lib/libLLVMMCParser.a lib/libclangSerialization.a lib/libLLVMBitReader.a lib/libclangSema.a lib/libclangEdit.a lib/libclangStaticAnalyzerCheckers.a lib/libclangStaticAnalyzerCore.a lib/libclangAnalysis.a lib/libclangAST.a lib/libclangRewrite.a lib/libclangLex.a lib/libclangBasic.a lib/libLLVMCore.a lib/libLLVMMC.a lib/libLLVMSupport.a || lib/libLLVMInstCombine.a lib/libLLVMAsmParser.a lib/libLLVMProfileData.a lib/libLLVMScalarOpts.a lib/libLLVMipo.a lib/libLLVMVectorize.a lib/libLLVMObjCARCOpts.a lib/libLLVMLinker.a lib/libLLVMAnalysis.a lib/libLLVMMC.a lib/libLLVMMCParser.a lib/libLLVMObject.a lib/libLLVMOption.a lib/libLLVMTarget.a tools/clang/include/clang/AST/ClangCommentCommandList tools/clang/include/clang/AST/ClangCommentCommandInfo tools/clang/include/clang/AST/ClangCommentHTMLNamedCharacterReferences tools/clang/include/clang/AST/ClangCommentHTMLTagsProperties tools/clang/include/clang/AST/ClangCommentNodes tools/clang/include/clang/AST/ClangAttrImpl tools/clang/include/clang/AST/ClangStmtNodes tools/clang/include/clang/AST/ClangAttrClasses tools/clang/include/clang/AST/ClangAttrDump tools/clang/include/clang/AST/ClangCommentHTMLTags tools/clang/include/clang/AST/ClangDeclNodes tools/clang/include/clang/AST/ClangAttrVisitor tools/clang/include/clang/Basic/ClangARMNeon tools/clang/include/clang/Basic/ClangDiagnosticIndexName tools/clang/include/clang/Basic/ClangDiagnosticParse tools/clang/include/clang/Basic/ClangDiagnosticFrontend tools/clang/include/clang/Basic/ClangDiagnosticSerialization tools/clang/include/clang/Basic/ClangDiagnosticLex tools/clang/include/clang/Basic/ClangDiagnosticCommon tools/clang/include/clang/Basic/ClangDiagnosticSema tools/clang/include/clang/Basic/ClangAttrList tools/clang/include/clang/Basic/ClangDiagnosticComment tools/clang/include/clang/Basic/ClangAttrHasAttributeImpl tools/clang/include/clang/Basic/ClangDiagnosticAST tools/clang/include/clang/Basic/ClangDiagnosticDriver tools/clang/include/clang/Basic/ClangDiagnosticGroups tools/clang/include/clang/Basic/ClangDiagnosticAnalysis tools/clang/include/clang/Parse/ClangAttrParserStringSwitches tools/clang/include/clang/Sema/ClangAttrParsedAttrList tools/clang/include/clang/Sema/ClangAttrTemplateInstantiate tools/clang/include/clang/Sema/ClangAttrSpellingListIndex tools/clang/include/clang/Sema/ClangAttrParsedAttrImpl tools/clang/include/clang/Sema/ClangAttrParsedAttrKinds tools/clang/include/clang/Serialization/ClangAttrPCHWrite tools/clang/include/clang/Serialization/ClangAttrPCHRead tools/clang/lib/Headers/clang-headers lib/libclangBasic.a lib/libclangLex.a lib/libclangParse.a lib/libclangAST.a lib/libclangSema.a lib/libclangCodeGen.a lib/libclangAnalysis.a lib/libclangEdit.a lib/libclangRewrite.a lib/libclangARCMigrate.a lib/libclangDriver.a lib/libclangSerialization.a lib/libclangFrontend.a lib/libclangRewriteFrontend.a lib/libclangFrontendTool.a lib/libclangStaticAnalyzerCore.a lib/libclangStaticAnalyzerCheckers.a lib/libclangStaticAnalyzerFrontend.a lib/libLLVM.dylib lib/libLLVMSupport.a lib/libLLVMCore.a lib/libLLVMIRReader.a lib/libLLVMBitReader.a lib/libLLVMBitWriter.a lib/libLLVMTransformUtils.a lib/libLLVMInstrumentation.a

It is actually impossible for your change to work as implemented because the libLLVM targets don’t exist until after clang, lld, and lldb targets are generated.

See the comment at the top of tools/CMakeLists.txt WRT ordering issues.

One of the other problems that you should account for is that not all tools and subprojects use AddLLVM. The AddLLVM macros shouldn't be calling `target_link_libraries` for LLVM libraries (I know the code did that in some places already and I'm not asking you to clean it up, just don't make it worse). Instead we should be relying on `llvm_config`. We should add an option "USE_SHARED" to `llvm_config`, and we should have code that filters the list of components passed into `explicit_llvm_config` based on the components included in the dylib and calls `target_link_libraries` as appropriate.

For this to work there are two changes required further out in CMake. (1) LLVM_DYLIB_COMPONENTS needs to be defined in the root CMakeLists (it can default to 'all'), and (2) tools/CMakeLists.txt needs to explicitly add llvm-shlib before any other tools.

It is probably reasonable to have `add_llvm_utility` default to not using the shared library, as I can't think of a single utility that is shipped as part of a distribution (and if there is one we should probably make it a tool).

http://reviews.llvm.org/D12488