[Analysis] Link library dependencies to Analysis plugins

[phosek]

Summary

These are needed to avoid undefined symbols which aren't satisfied
by Clang itself.

[phosek]

This is an alternative to D62154. With just the change to HandleLLVMOptions.cmake, we're seeing errors in Analysis plugins due to undefined symbols:

error: 'error' diagnostics seen but not expected:
  (frontend): unable to load plugin './lib/SampleAnalyzerPlugin.so': './lib/SampleAnalyzerPlugin.so: undefined symbol: _ZN4llvm14FoldingSetBase6anchorEv'

and

bin/clang: symbol lookup error: ./lib/SampleAnalyzerPlugin.so: undefined symbol: _ZN5clang4ento15CheckerRegistry10addCheckerEPFvRNS0_14CheckerManagerEEPFbRKNS_11LangOptionsEEN4llvm9StringRefESC_SC_b

I'm not sure where those symbols are supposed to come from, but they're not part of Clang so those errors seem valid. Linking in dependencies unconditionally addresses those failures.

Note that I've been testing this in build of Clang that enables neither shared libraries nor libLLVM.so.

[hintonda]

LGTM. Build and check-llvm were both clean on my Mac for static build. Thanks!

[davezarzycki]

This breaks non-PIC builds. Was this planned or expected? Can we revert this until a fix is found?

[davezarzycki]

Fixed: r361399

clang/test/Analysis/plugins/CheckerDependencyHandling/CMakeLists.txt

 set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/CheckerDependencyHandlingAnalyzerPlugin.exports)
 add_llvm_library(CheckerDependencyHandlingAnalyzerPlugin MODULE CheckerDependencyHandling.cpp PLUGIN_TOOL clang)
 
-if(LLVM_ENABLE_PLUGINS AND (WIN32 OR CYGWIN))
+if(LLVM_ENABLE_PLUGINS)
   target_link_libraries(CheckerDependencyHandlingAnalyzerPlugin PRIVATE
     clangAnalysis
     clangAST
     clangStaticAnalyzerCore
+    clangStaticAnalyzerFrontend
     LLVMSupport
     )
 endif()

clang/test/Analysis/plugins/CheckerOptionHandling/CMakeLists.txt

 set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/CheckerOptionHandlingAnalyzerPlugin.exports)
 add_llvm_library(CheckerOptionHandlingAnalyzerPlugin MODULE CheckerOptionHandling.cpp PLUGIN_TOOL clang)
 
-if(LLVM_ENABLE_PLUGINS AND (WIN32 OR CYGWIN))
+if(LLVM_ENABLE_PLUGINS)
   target_link_libraries(CheckerOptionHandlingAnalyzerPlugin PRIVATE
     clangAnalysis
     clangAST
     clangStaticAnalyzerCore
+    clangStaticAnalyzerFrontend
     LLVMSupport
     )
 endif()

clang/test/Analysis/plugins/SampleAnalyzer/CMakeLists.txt

 set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/SampleAnalyzerPlugin.exports)
 add_llvm_library(SampleAnalyzerPlugin MODULE MainCallChecker.cpp PLUGIN_TOOL clang)
 
-if(LLVM_ENABLE_PLUGINS AND (WIN32 OR CYGWIN))
+if(LLVM_ENABLE_PLUGINS)
   target_link_libraries(SampleAnalyzerPlugin PRIVATE
     clangAnalysis
     clangAST
     clangStaticAnalyzerCore
+    clangStaticAnalyzerFrontend
     LLVMSupport
     )
 endif()

llvm/cmake/modules/HandleLLVMOptions.cmake

if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
   message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
 endif()
 if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
   message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
 endif()
 
 # Plugin support
 # FIXME: Make this configurable.
+if(WIN32 OR CYGWIN)
   if(BUILD_SHARED_LIBS OR LLVM_BUILD_LLVM_DYLIB)
     set(LLVM_ENABLE_PLUGINS ON)
   else()
     set(LLVM_ENABLE_PLUGINS OFF)
   endif()
+else()
+  set(LLVM_ENABLE_PLUGINS ON)
+endif()
 
 # By default we should enable LLVM_ENABLE_IDE only for multi-configuration
 # generators. This option disables optional build system features that make IDEs
 # less usable.
 set(LLVM_ENABLE_IDE_default OFF)
 if (CMAKE_CONFIGURATION_TYPES)
   set(LLVM_ENABLE_IDE_default ON)
 endif()