[OpenMP] Fix layering problem with FrontendOpenMP

[jdoerfert]

Summary

ASTMatchers is used in various places and it now exposes the
LLVMFrontendOpenMP library to its users without them needing to depend
on it explicitly.

[lebedev.ri]

LG

[sylvestre.ledru]

@lebedev.ri @jdoerfert Looks like it might have caused:
https://bugs.llvm.org/show_bug.cgi?id=45453

[aheejin]

Could you revert this patch? This is causing an error like this whenever I run clang binary:

: CommandLine Error: Option 'openmp-ir-builder-optimistic-attributes' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options

This happens when clang is built with -DLLVM_LINK_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB=ON.

[jdoerfert]

In D77574#1967141, @aheejin wrote:

Could you revert this patch? This is causing an error like this whenever I run clang binary:

: CommandLine Error: Option 'openmp-ir-builder-optimistic-attributes' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options

This happens when clang is built with -DLLVM_LINK_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB=ON.

I'll revert it. Is there a buildbot with this configuration? Do you happen to have insights on how to resolve the issue?

[aheejin]

Thanks. Not sure if there's a buildbot that uses -DLLVM_LINK_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB=ON, but I think you can build with it yourself to reproduce it. About how to resolve the issue, I have no idea, sorry.

[tstellar]

clang/lib/ASTMatchers/CMakeLists.txt

17–18

My guess is that this is the problem. Making this change will cause clang binaries to link against the LLVMFrontendOpenMP static library in addition to libLLVM.so (which already contains this library).

clang-tools-extra/clang-reorder-fields/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   support
 )
 
 add_clang_library(clangReorderFields
   ReorderFieldsAction.cpp
 
   LINK_LIBS
   clangAST

clang-tools-extra/clang-tidy/openmp/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support)
 
 add_clang_library(clangTidyOpenMPModule
   ExceptionEscapeCheck.cpp
   OpenMPTidyModule.cpp
   UseDefaultNoneCheck.cpp
 
   LINK_LIBS
   clangAST
   clangASTMatchers
   clangBasic
   clangTidy
   clangTidyUtils
   )

clang/lib/ASTMatchers/CMakeLists.txt

 add_subdirectory(Dynamic)
 
 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
 )
 
 add_clang_library(clangASTMatchers
   ASTMatchFinder.cpp
   ASTMatchersInternal.cpp
   GtestMatchers.cpp
 
   LINK_LIBS
   clangAST
   clangBasic
   clangLex
   )
+
+target_link_libraries(clangASTMatchers PUBLIC LLVMFrontendOpenMP)

clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 add_clang_library(clangStaticAnalyzerCheckers
   AnalysisOrderChecker.cpp
   AnalyzerStatsChecker.cpp
   ArrayBoundChecker.cpp
   ArrayBoundCheckerV2.cpp

clang/lib/StaticAnalyzer/Core/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
 )
 
 add_clang_library(clangStaticAnalyzerCore
   APSIntType.cpp
   AnalysisManager.cpp
   AnalyzerOptions.cpp
   BasicValueFactory.cpp

clang/lib/Tooling/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Option
-  FrontendOpenMP
   Support
   )
 
 add_subdirectory(Core)
 add_subdirectory(Inclusions)
 add_subdirectory(Refactoring)
 add_subdirectory(ASTDiff)
 add_subdirectory(Syntax)

clang/lib/Tooling/Transformer/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
 )
 
 add_clang_library(clangTransformer
   RangeSelector.cpp
   RewriteRule.cpp
   SourceCode.cpp
   SourceCodeBuilders.cpp

clang/unittests/AST/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 if (MSVC)
   set_source_files_properties(ASTImporterTest.cpp PROPERTIES COMPILE_FLAGS /bigobj)
 endif()
 
 add_clang_unittest(ASTTests

clang/unittests/ASTMatchers/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 # By default MSVC has a 2^16 limit on the number of sections in an object file,
 # and this needs more than that.
 if (MSVC)
   set_source_files_properties(InternalASTMatchersTest.cpp PROPERTIES COMPILE_FLAGS /bigobj)
   set_source_files_properties(NodeMatchersTest.cpp PROPERTIES COMPILE_FLAGS /bigobj)

clang/unittests/ASTMatchers/Dynamic/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 add_clang_unittest(DynamicASTMatchersTests
   VariantValueTest.cpp
   ParserTest.cpp
   RegistryTest.cpp
   )

clang/unittests/Analysis/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 add_clang_unittest(ClangAnalysisTests
   CFGDominatorTree.cpp
   CFGTest.cpp
   CloneDetectionTest.cpp
   ExprMutationAnalyzerTest.cpp

clang/unittests/Rename/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   support
   )
 
 # We'd like clang/unittests/Tooling/RewriterTestContext.h in the test.
 include_directories(${CLANG_SOURCE_DIR})
 
 add_clang_unittest(ClangRenameTests
   RenameClassTest.cpp

clang/unittests/Sema/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 add_clang_unittest(SemaTests
   ExternalSemaSourceTest.cpp
   CodeCompleteTest.cpp
   GslOwnerPointerInference.cpp
   )

clang/unittests/StaticAnalyzer/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  FrontendOpenMP
   Support
   )
 
 add_clang_unittest(StaticAnalysisTests
   AnalyzerOptionsTest.cpp
   CallDescriptionTest.cpp
   StoreTest.cpp
   RegisterCustomCheckersTest.cpp

clang/unittests/Tooling/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
-  FrontendOpenMP
   Support
   )
 
 # By default MSVC has a 2^16 limit on the number of sections in an object file,
 # and this needs more than that.
 if (MSVC)
   set_source_files_properties(RecursiveASTVisitorTest.cpp PROPERTIES COMPILE_FLAGS /bigobj)
   set_source_files_properties(RecursiveASTVisitorTestExprVisitor.cpp PROPERTIES COMPILE_FLAGS /bigobj)