[CMake] Use generator expression to get in-tree libc++ path

When using the in-tree libc++, we should be using the full path to
ensure that we're using the right library and not accidentally pick up
the system library.

Differential Revision: https://reviews.llvm.org/D118200

compiler-rt/CMakeLists.txt

@@ -532,16 +532,17 @@ endif()
 
 if (SANITIZER_TEST_CXX_LIBNAME STREQUAL "libc++")
   if (SANITIZER_TEST_CXX_INTREE)
-    if (SANITIZER_USE_STATIC_TEST_CXX AND (TARGET cxx_static OR HAVE_LIBCXX))
-      list(APPEND SANITIZER_TEST_CXX_LIBRARIES cxx_static)
-    elseif (TARGET cxx_shared OR HAVE_LIBCXX)
-      list(APPEND SANITIZER_TEST_CXX_LIBRARIES cxx_shared)
+    if (SANITIZER_USE_STATIC_TEST_CXX)
+      set(cxx_target cxx_static)
+    else()
+      set(cxx_target cxx_shared)
     endif()
+    list(APPEND SANITIZER_TEST_CXX_LIBRARIES "$<$<BOOL:$<TARGET_NAME_IF_EXISTS:${cxx_target}>>:$<TARGET_LINKER_FILE:${cxx_target}>>")
   else()
-    append_list_if(COMPILER_RT_HAS_LIBCXX c++ SANITIZER_TEST_CXX_LIBRARIES)
+    append_list_if(COMPILER_RT_HAS_LIBCXX -lc++ SANITIZER_TEST_CXX_LIBRARIES)
   endif()
 elseif (SANITIZER_TEST_CXX_LIBNAME STREQUAL "libstdc++")
-  append_list_if(COMPILER_RT_HAS_LIBSTDCXX stdc++ SANITIZER_TEST_CXX_LIBRARIES)
+  append_list_if(COMPILER_RT_HAS_LIBSTDCXX -lstdc++ SANITIZER_TEST_CXX_LIBRARIES)
 endif()
 
 # TODO: There's a lot of duplication across lib/*/tests/CMakeLists.txt files,

compiler-rt/lib/memprof/tests/CMakeLists.txt

@@ -36,9 +36,8 @@ if(NOT WIN32)
   list(APPEND MEMPROF_UNITTEST_LINK_FLAGS -pthread)
 endif()
 
-foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
-  list(APPEND MEMPROF_UNITTEST_LINK_FLAGS -l${lib})
-endforeach()
+set(MEMPROF_UNITTEST_LINK_LIBRARIES ${SANITIZER_TEST_CXX_LIBRARIES})
+list(APPEND MEMPROF_UNITTEST_LINK_LIBRARIES "dl")
 
 if(COMPILER_RT_DEFAULT_TARGET_ARCH IN_LIST MEMPROF_SUPPORTED_ARCH)
   # MemProf unit tests are only run on the host machine.
@@ -55,7 +54,7 @@ if(COMPILER_RT_DEFAULT_TARGET_ARCH IN_LIST MEMPROF_SUPPORTED_ARCH)
     $<TARGET_OBJECTS:RTSanitizerCommonSymbolizer.${arch}>)
   set_target_compile_flags(MemProfUnitTests ${MEMPROF_UNITTEST_CFLAGS})
   set_target_link_flags(MemProfUnitTests ${MEMPROF_UNITTEST_LINK_FLAGS})
-  target_link_libraries(MemProfUnitTests dl)
+  target_link_libraries(MemProfUnitTests ${MEMPROF_UNITTEST_LINK_LIBRARIES})
 
   if (TARGET cxx-headers OR HAVE_LIBCXX)
     add_dependencies(MemProfUnitTests cxx-headers)

compiler-rt/lib/orc/unittests/CMakeLists.txt

@@ -37,6 +37,7 @@ set(ORC_TEST_ARCH ${ORC_SUPPORTED_ARCH})
 set(ORC_UNITTEST_LINK_FLAGS
   ${COMPILER_RT_UNITTEST_LINK_FLAGS}
   ${CMAKE_THREAD_LIBS_INIT}
+  ${SANITIZER_TEST_CXX_LIBRARIES}
   )
 
 if(APPLE)
@@ -51,10 +52,6 @@ else()
   append_list_if(COMPILER_RT_HAS_LIBEXECINFO -lexecinfo ORC_UNITTEST_LINK_FLAGS)
 endif()
 
-foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
-  list(APPEND ORC_UNITTEST_LINK_FLAGS -l${lib})
-endforeach()
-
 set(ORC_DEPS gtest orc)
 # ORC uses C++ standard library headers.
 if (TARGET cxx-headers OR HAVE_LIBCXX)

compiler-rt/lib/scudo/standalone/tests/CMakeLists.txt

@@ -33,10 +33,10 @@ endif()
 set(SCUDO_TEST_ARCH ${SCUDO_STANDALONE_SUPPORTED_ARCH})
 
 # gtests requires c++
-set(LINK_FLAGS ${COMPILER_RT_UNITTEST_LINK_FLAGS})
-foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
-  list(APPEND LINK_FLAGS -l${lib})
-endforeach()
+set(LINK_FLAGS
+  ${COMPILER_RT_UNITTEST_LINK_FLAGS}
+  ${SANITIZER_TEST_CXX_LIBRARIES}
+  )
 list(APPEND LINK_FLAGS -pthread)
 # Linking against libatomic is required with some compilers
 check_library_exists(atomic __atomic_load_8 "" COMPILER_RT_HAS_LIBATOMIC)

compiler-rt/lib/tsan/tests/CMakeLists.txt

@@ -24,10 +24,10 @@ append_list_if(COMPILER_RT_HAS_MSSE4_2_FLAG -msse4.2 TSAN_UNITTEST_CFLAGS)
 
 set(TSAN_TEST_ARCH ${TSAN_SUPPORTED_ARCH})
 
-set(LINK_FLAGS ${COMPILER_RT_UNITTEST_LINK_FLAGS})
-foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
-  list(APPEND LINK_FLAGS -l${lib})
-endforeach()
+set(LINK_FLAGS
+  ${COMPILER_RT_UNITTEST_LINK_FLAGS}
+  ${SANITIZER_TEST_CXX_LIBRARIES}
+  )
 
 if(APPLE)
 

compiler-rt/lib/xray/tests/CMakeLists.txt

@@ -50,6 +50,7 @@ set(XRAY_TEST_ARCH ${XRAY_SUPPORTED_ARCH})
 set(XRAY_UNITTEST_LINK_FLAGS
   ${COMPILER_RT_UNITTEST_LINK_FLAGS}
   ${CMAKE_THREAD_LIBS_INIT}
+  ${SANITIZER_TEST_CXX_LIBRARIES}
   )
 
 if (NOT APPLE)
@@ -82,10 +83,6 @@ if (NOT APPLE)
   append_list_if(COMPILER_RT_HAS_LIBEXECINFO -lexecinfo XRAY_UNITTEST_LINK_FLAGS)
 endif()
 
-foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
-  list(APPEND XRAY_UNITTEST_LINK_FLAGS -l${lib})
-endforeach()
-
 macro(add_xray_unittest testname)
   cmake_parse_arguments(TEST "" "" "SOURCES;HEADERS" ${ARGN})
   if(UNIX AND NOT APPLE)