[libcxxabi] Use cxx-headers target to consume libcxx headers

Rather than including libc++ include dir, use the cxx-headers target.

Differential Revision: https://reviews.llvm.org/D98367

libcxxabi/CMakeLists.txt

@@ -156,9 +156,23 @@ if (NOT LIBCXXABI_ENABLE_SHARED AND NOT LIBCXXABI_ENABLE_STATIC)
   message(FATAL_ERROR "libc++abi must be built as either a shared or static library.")
 endif()
 
-set(LIBCXXABI_LIBCXX_INCLUDES "${LIBCXXABI_LIBCXX_PATH}/include" CACHE PATH
+# TODO: This is a workaround for the fact that Standalone builds can't use
+# targets from the other runtimes (so the cxx-headers target doesn't exist).
+set(LIBCXXABI_LIBCXX_INCLUDES "" CACHE PATH
     "Specify path to libc++ includes.")
-message(STATUS "Libc++abi will be using libc++ includes from ${LIBCXXABI_LIBCXX_INCLUDES}")
+if (LIBCXXABI_STANDALONE_BUILD)
+  if (NOT IS_DIRECTORY ${LIBCXXABI_LIBCXX_INCLUDES})
+    message(FATAL_ERROR
+      "LIBCXXABI_LIBCXX_INCLUDES=${LIBCXXABI_LIBCXX_INCLUDES} is not a valid directory. "
+      "Please provide the path to where the libc++ headers have been installed.")
+  endif()
+  add_library(cxx-headers INTERFACE)
+  if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC" OR "${CMAKE_CXX_SIMULATE_ID}" STREQUAL "MSVC")
+    target_compile_options(cxx-headers INTERFACE /I "${LIBCXXABI_LIBCXX_INCLUDES}")
+  else()
+    target_compile_options(cxx-headers INTERFACE -I "${LIBCXXABI_LIBCXX_INCLUDES}")
+  endif()
+endif()
 
 option(LIBCXXABI_HERMETIC_STATIC_LIBRARY
   "Do not export any symbols from the static library." OFF)
@@ -180,6 +194,7 @@ set(CMAKE_MODULE_PATH
   )
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   if(LIBCXX_LIBDIR_SUBDIR)
@@ -187,9 +202,11 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
   endif()
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+  set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
 else()
+  set(LIBCXXABI_HEADER_DIR ${CMAKE_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
 endif()

libcxxabi/src/CMakeLists.txt

@@ -56,8 +56,6 @@ if (MSVC_IDE OR XCODE)
   endif()
 endif()
 
-include_directories("${LIBCXXABI_LIBCXX_INCLUDES}")
-
 # stdlib_stdexcept.cpp depends on libc++ internals.
 include_directories("${LIBCXXABI_LIBCXX_PATH}")
 
@@ -178,7 +176,7 @@ endif()
 # Build the shared library.
 if (LIBCXXABI_ENABLE_SHARED)
   add_library(cxxabi_shared SHARED ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})
-  target_link_libraries(cxxabi_shared PRIVATE ${LIBCXXABI_SHARED_LIBRARIES} ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_shared PRIVATE cxx-headers ${LIBCXXABI_SHARED_LIBRARIES} ${LIBCXXABI_LIBRARIES})
   if (TARGET pstl::ParallelSTL)
     target_link_libraries(cxxabi_shared PUBLIC pstl::ParallelSTL)
   endif()
@@ -245,7 +243,7 @@ endif()
 # Build the static library.
 if (LIBCXXABI_ENABLE_STATIC)
   add_library(cxxabi_static STATIC ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})
-  target_link_libraries(cxxabi_static PRIVATE ${LIBCXXABI_STATIC_LIBRARIES} ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_static PRIVATE cxx-headers ${LIBCXXABI_STATIC_LIBRARIES} ${LIBCXXABI_LIBRARIES})
   if (TARGET pstl::ParallelSTL)
     target_link_libraries(cxxabi_static PUBLIC pstl::ParallelSTL)
   endif()

libcxxabi/test/libcxxabi/test/config.py

@@ -16,12 +16,16 @@ class Configuration(LibcxxConfiguration):
     # pylint: disable=redefined-outer-name
     def __init__(self, lit_config, config):
         super(Configuration, self).__init__(lit_config, config)
+        self.libcxxabi_hdr_root = None
         self.libcxxabi_src_root = None
         self.libcxxabi_obj_root = None
         self.abi_library_root = None
         self.libcxx_src_root = None
 
     def configure_src_root(self):
+        self.libcxxabi_hdr_root = self.get_lit_conf(
+            'libcxxabi_hdr_root',
+            self.project_obj_root)
         self.libcxxabi_src_root = self.get_lit_conf(
             'libcxxabi_src_root',
             os.path.dirname(self.config.test_source_root))
@@ -57,9 +61,8 @@ class Configuration(LibcxxConfiguration):
 
     def configure_compile_flags_header_includes(self):
         self.configure_config_site_header()
-        cxx_headers = self.get_lit_conf(
-            'cxx_headers',
-            os.path.join(self.libcxx_src_root, '/include'))
+        cxx_headers = self.get_lit_conf('cxx_headers', None) or \
+            os.path.join(self.libcxxabi_hdr_root, 'include', 'c++', 'v1')
         if cxx_headers == '':
             self.lit_config.note('using the systems c++ headers')
         else:

libcxxabi/test/lit.site.cfg.in

@@ -5,6 +5,7 @@ import site
 
 config.cxx_under_test           = "@CMAKE_CXX_COMPILER@"
 config.project_obj_root         = "@CMAKE_BINARY_DIR@"
+config.libcxxabi_hdr_root       = "@LIBCXXABI_HEADER_DIR@"
 config.libcxxabi_src_root       = "@LIBCXXABI_SOURCE_DIR@"
 config.libcxxabi_obj_root       = "@LIBCXXABI_BINARY_DIR@"
 config.abi_library_root         = "@LIBCXXABI_LIBRARY_DIR@"