[clang][unittests] Fix a clang unittest linking issue

[SixWeining]

Summary

Currently the clang/unittests/Basic/CMakeLists.txt links LLVMTestingSupport in an incorrect way that would cause ninja check-clang failing with a linking error when the LLVM_LINK_LLVM_DYLIB variable is set to ON:

$ cmake ../llvm -DLLVM_ENABLE_PROJECTS="clang" \

-DLLVM_TARGETS_TO_BUILD="X86"           \
-DCMAKE_BUILD_TYPE=Release              \
-DLLVM_ENABLE_ASSERTIONS=ON             \
-DLLVM_LINK_LLVM_DYLIB=ON               \
-G Ninja

$ ninja check-clang

...

/usr/bin/ld: tools/clang/unittests/Basic/CMakeFiles/BasicTests.dir/FileManagerTest.cpp.o: in function `(anonymous namespace)::FileManagerTest_getBypassFile_Test::TestBody()':
FileManagerTest.cpp:(.text._ZN12_GLOBAL__N_134FileManagerTest_getBypassFile_Test8TestBodyEv+0x3a3): undefined reference to `llvm::detail::TakeError(llvm::Error)'

This patch changes the linking method of LLVMTestingSupport from clang_target_link_libraries to target_link_libraries just like other tests have done.

[SixWeining]

Modify the summary to be more descriptive.

[SixWeining]

diff1 and diff2 are the same, but diff1 build pass while diff2 build fail. So weird. Just reupload the patch to have a try. Sorry for the noise.

[dexonsmith]

LGTM. Sorry for missing this before. Looks to me like the debian build failure above is unrelated.

If you need someone to commit for you, please include the info for GIT_AUTHOR_NAME and GIT_AUTHOR_EMAIL.

[SixWeining]

In D114505#3181637, @dexonsmith wrote:

LGTM. Sorry for missing this before. Looks to me like the debian build failure above is unrelated.

If you need someone to commit for you, please include the info for GIT_AUTHOR_NAME and GIT_AUTHOR_EMAIL.

Thanks @dexonsmith . I don't have commit access, could you help to land this patch for me? Please use below info to commit the change.

	email = [e-mail]
	name = Weining Lu

BTW, according to the policy, a "Differential Revision: <URL>" line should be added to the commit message. But it seems that I'm not allowed to add such line without commit access. Could you help to add it?

[SixWeining]

ping

[dexonsmith]

Lost track of this again :/. Was just about to commit this for you (finally) but it looks like https://reviews.llvm.org/D115580 has already fixed it.

[SixWeining]

Abandon because https://reviews.llvm.org/D115580 has already fixed it although later than my fix.

Thanks @dexonsmith

clang/unittests/Basic/CMakeLists.txt

add_clang_unittest(BasicTests
   SourceManagerTest.cpp
   )
 
 clang_target_link_libraries(BasicTests
   PRIVATE
   clangAST
   clangBasic
   clangLex
+  )
+
+target_link_libraries(BasicTests
+  PRIVATE
   LLVMTestingSupport
-  )