[libcxx] Cleanup CMake configuration and integrate with LLVM

[EricWF]

Summary

This patch contains the following changes:

1. Require that libc++ can find a LLVM source directory. This is done the same way as libc++abi currently does.
2. Cleanup ugly configuration code in CMakeLists.txt by using add_flags, add_flags_if, and add_flags_if_supported macros.

The goals for this patch are:

1. Help libc++ be more consistent with how LLVM handles CMake options (see PR23670 PR23671).
2. Make it easier to use sanitizers using the LLVM_USE_SANITIZER option.
3. Make libc++'s CMakeLists.txt file easier to understand and change.
4. Move towards allowing libc++ to create Sphinx documentation (see http://efcs.ca/libcxx-docs).
5. Move towards allowing libc++ to use other LLVM utilities such as not and FileCheck.

[EricWF]

Add comments in HandleLibcxxFlags.cmake.

[EricWF]

Update so that the patch applies cleanly to master.

[danalbert]

CMakeLists.txt

64

Nit: the other descriptions end with a period

105

This sentence doesn't make sense. "Set foo to bar is on..." ?

[EricWF]

Address @danalbert's comments.

[danalbert]

LGTM.

CMakeLists.txt

  build directory and run 'cmake /path/to/${PROJECT_NAME} [options]' there."
  )
 
-if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
-  set(LIBCXX_LIBDIR_SUFFIX "" CACHE STRING
-      "Define suffix of library directory name (32/64)")
-
-  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
-  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
-
-  set(LIBCXX_BUILT_STANDALONE 1)
-else()
-  set(LIBCXX_LIBDIR_SUFFIX ${LLVM_LIBDIR_SUFFIX})
-endif()
+# Find the required bits of LLVM
+include(FindLLVM)
+# Include the LLVM CMake functions.
+include(AddLLVM)
 
 #===============================================================================
 # Setup CMake Options
 #===============================================================================
 
-# Define options.
-option(LIBCXX_ENABLE_EXCEPTIONS "Use exceptions." ON)
-option(LIBCXX_ENABLE_RTTI "Use run time type information." ON)
+# Basic options ---------------------------------------------------------------
 option(LIBCXX_ENABLE_ASSERTIONS "Enable assertions independent of build mode." ON)
-option(LIBCXX_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
-option(LIBCXX_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
-option(LIBCXX_ENABLE_CXX1Y "Enable -std=c++1y and use of c++1y language features if the compiler supports it." OFF)
 option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
+
+set(LIBCXX_LIBDIR_SUFFIX "${LLVM_LIBDIR_SUFFIX}" CACHE STRING
+    "Define suffix of library directory name (32/64)")
+option(LIBCXX_INSTALL_HEADERS "Install the libc++ headers." ON)
+option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
+
+# ABI Library options ---------------------------------------------------------
+set(LIBCXX_CXX_ABI "${LIBCXX_CXX_ABI}" CACHE STRING
+    "Specify C++ ABI library to use." FORCE)
+set(CXXABIS none libcxxabi libcxxrt libstdc++ libsupc++)
+set_property(CACHE LIBCXX_CXX_ABI PROPERTY STRINGS ;${CXXABIS})
+
+option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "Statically link the ABI library" OFF)
+
+# Build libc++abi with libunwind. We need this option to determine whether to
+# link with libunwind or libgcc_s while running the test cases.
+option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder." OFF)
+
+# Target options --------------------------------------------------------------
+option(LIBCXX_BUILD_32_BITS "Build 32 bit libc++" OFF)
+set(LIBCXX_SYSROOT "" CACHE STRING "Use alternate sysroot.")
+set(LIBCXX_GCC_TOOLCHAIN "" CACHE STRING "Use alternate GCC toolchain.")
+
+# Feature options -------------------------------------------------------------
+option(LIBCXX_ENABLE_EXCEPTIONS "Use exceptions." ON)
+option(LIBCXX_ENABLE_RTTI "Use run time type information." ON)
 option(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE "Build libc++ with support for the global filesystem namespace." ON)
 option(LIBCXX_ENABLE_STDIN "Build libc++ with support for stdin/std::cin." ON)
 option(LIBCXX_ENABLE_STDOUT "Build libc++ with support for stdout/std::cout." ON)
 option(LIBCXX_ENABLE_THREADS "Build libc++ with support for threads." ON)
 option(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS "Build libc++ with support for thread-unsafe C functions" ON)
-option(LIBCXX_BUILD_32_BITS "Build 32 bit libc++" OFF)
 option(LIBCXX_ENABLE_MONOTONIC_CLOCK
   "Build libc++ with support for a monotonic clock.
    This option may only be used when LIBCXX_ENABLE_THREADS=OFF." ON)
-option(LIBCXX_INSTALL_HEADERS "Install the libc++ headers." ON)
-option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
+
+# Misc options ----------------------------------------------------------------
+option(LIBCXX_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
+option(LIBCXX_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
+
 option(LIBCXX_GENERATE_COVERAGE "Enable generating code coverage." OFF)
 set(LIBCXX_COVERAGE_LIBRARY "" CACHE STRING
-       "The Profile-rt library used to build with code coverage")
-option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "Statically link the ABI library" OFF)
-set(LIBCXX_SYSROOT "" CACHE STRING "Use alternate sysroot.")
-set(LIBCXX_GCC_TOOLCHAIN "" CACHE STRING "Use alternate GCC toolchain.")
-if (LIBCXX_BUILT_STANDALONE)
-  set(LLVM_USE_SANITIZER "" CACHE STRING
-      "Define the sanitizer used to build the library and tests")
+
+#===============================================================================
+# Check option configurations
+#===============================================================================
+
+# Ensure LIBCXX_ENABLE_MONOTONIC_CLOCK is set to ON only when
+# LIBCXX_ENABLE_THREADS is on.
+if(LIBCXX_ENABLE_THREADS AND NOT LIBCXX_ENABLE_MONOTONIC_CLOCK)
+  message(FATAL_ERROR "LIBCXX_ENABLE_MONOTONIC_CLOCK can only be set to OFF"
+                      " when LIBCXX_ENABLE_THREADS is also set to OFF.")
 endif()
 
+# Ensure LLVM_USE_SANITIZER is not specified when LIBCXX_GENERATE_COVERAGE
+# is ON.
+if (LLVM_USE_SANITIZER AND LIBCXX_GENERATE_COVERAGE)
+  message(FATAL_ERROR "LLVM_USE_SANITIZER cannot be used with LIBCXX_GENERATE_COVERAGE")
+endif()
+
+# Set LIBCXX_BUILD_32_BITS to LLVM_BUILD_32_BITS is on and check that
+# we can build with 32 bits
+if (CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32)
+  if (LIBCXX_BUILD_32_BITS OR LLVM_BUILD_32_BITS)
+    if (NOT LLVM_BUILD_32_BITS)
+      message(STATUS "Building 32 bits executables and libraries.")
+    endif()
+    set(LIBCXX_BUILD_32_BITS ON CACHE BOOL "" FORCE)
+  endif()
+elseif(LIBCXX_BUILD_32_BITS)
+  message(FATAL_ERROR "LIBCXX_BUILD_32_BITS=ON is not supported on this platform.")
+endif()
+
+# Check that this option is not enabled on Apple and emit a usage warning.
 if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
   if (APPLE)
     message(FATAL_ERROR "LIBCXX_ENABLE_STATIC_ABI_LIBRARY is not supported on OS X")

   endif()
 endif()
 
-set(CXXABIS none libcxxabi libcxxrt libstdc++ libsupc++)
-if (NOT LIBCXX_CXX_ABI)
-  if (NOT DEFINED LIBCXX_BUILT_STANDALONE AND
-      IS_DIRECTORY "${CMAKE_SOURCE_DIR}/projects/libcxxabi")
-    set(LIBCXX_CXX_ABI_LIBNAME "libcxxabi")
-    set(LIBCXX_CXX_ABI_INCLUDE_PATHS "${CMAKE_SOURCE_DIR}/projects/libcxxabi/include")
-    set(LIBCXX_CXX_ABI_INTREE 1)
-  else ()
-    set(LIBCXX_CXX_ABI_LIBNAME "none")
-  endif ()
-else ()
-  set(LIBCXX_CXX_ABI_LIBNAME "${LIBCXX_CXX_ABI}")
-endif ()
-set(LIBCXX_CXX_ABI "${LIBCXX_CXX_ABI}" CACHE STRING
-    "Specify C++ ABI library to use." FORCE)
-set_property(CACHE LIBCXX_CXX_ABI PROPERTY STRINGS ;${CXXABIS})
-
-# Build libc++abi with libunwind. We need this option to determine whether to
-# link with libunwind or libgcc_s while running the test cases.
-option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder." OFF)
-
 #===============================================================================
 # Configure System
 #===============================================================================

 set(LIBCXX_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
 
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
+
 # Declare libc++ configuration variables.
 # They are intended for use as follows:
 # LIBCXX_CXX_FLAGS: General flags for both the compiler and linker.
 # LIBCXX_COMPILE_FLAGS: Compile only flags.
 # LIBCXX_LINK_FLAGS: Linker only flags.
-set(LIBCXX_CXX_FLAGS "")
 set(LIBCXX_COMPILE_FLAGS "")
 set(LIBCXX_LINK_FLAGS "")
+set(LIBCXX_LIBRARIES "")
 
 # Configure compiler.
 include(config-ix)
-# Configure ABI library
-include(HandleLibCXXABI)
+
 # Configure coverage options.
 if (LIBCXX_GENERATE_COVERAGE)
   include(CodeCoverage)
   set(CMAKE_BUILD_TYPE "COVERAGE" CACHE STRING "" FORCE)
 endif()
 
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+
 #===============================================================================
 # Setup Compiler Flags
 #===============================================================================
+include(HandleLLVMOptions) # Setup LLVM flags
 
-# Get required flags.
-# On all systems the system c++ standard library headers need to be excluded.
-if (MSVC)
-  # MSVC only has -X, which disables all default includes; including the crt.
-  # Thus, we do nothing and hope we don't accidentally include any of the C++
-  # headers.
-else()
-  if (LIBCXX_HAS_NOSTDINCXX_FLAG)
-    list(APPEND LIBCXX_COMPILE_FLAGS -nostdinc++)
-    string(REPLACE "-stdlib=libc++" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    string(REPLACE "-stdlib=libstdc++" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-  endif()
-  # If c++1y has been enabled then attempt to use it. Fail if it is no supported
-  # by the compiler. Otherwise choose c++11 and ensure the compiler supports it.
-  if (LIBCXX_ENABLE_CXX1Y)
-    if (LIBCXX_HAS_STDCXX1Y_FLAG)
-      set(LIBCXX_STD_VERSION c++1y)
-    else()
-      message(FATAL_ERROR "c++1y was enabled but the compiler does not support it.")
-    endif()
-  else()
-    if (LIBCXX_HAS_STDCXX11_FLAG)
-      set(LIBCXX_STD_VERSION c++11)
-    else()
-      message(FATAL_ERROR "c++11 is required by libc++ but is not supported by the compiler")
-    endif()
-  endif()
-  # LIBCXX_STD_VERSION should always be set at this point.
-  list(APPEND LIBCXX_CXX_FLAGS "-std=${LIBCXX_STD_VERSION}")
-endif()
+include(HandleLibCXXABI) # Steup the ABI library flags
 
-macro(append_if list condition var)
-  if (${condition})
-    list(APPEND ${list} ${var})
-  endif()
-endmacro()
+# Include macros for adding and removing libc++ flags.
+include(HandleLibcxxFlags)
+
+# Remove flags that may have snuck in.
+remove_flags(-DNDEBUG -UNDEBUG -D_DEBUG
+             -stdlib=libc++ -stdlib=libstdc++ -lc++abi -m32)
 
-# Get warning flags
-if (NOT MSVC)
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WALL_FLAG -Wall)
-  list(APPEND LIBCXX_COMPILE_FLAGS -Werror=return-type)
+# Required flags ==============================================================
+add_compile_flags_if_supported(-std=c++11)
+if (NOT MSVC AND NOT LIBCXX_SUPPORTS_STD_EQ_CXX11_FLAG)
+  message(FATAL_ERROR "C++11 is required but the compiler does not support -std=c++11")
 endif()
 
-append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_W_FLAG -W)
-append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WNO_UNUSED_PARAMETER_FLAG -Wno-unused-parameter)
-append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WWRITE_STRINGS_FLAG -Wwrite-strings)
-append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WNO_LONG_LONG_FLAG -Wno-long-long)
+# On all systems the system c++ standard library headers need to be excluded.
+# MSVC only has -X, which disables all default includes; including the crt.
+# Thus, we do nothing and hope we don't accidentally include any of the C++
+# headers
+add_compile_flags_if_supported(-nostdinc++)
+
+# Target flags ================================================================
+add_flags_if(LIBCXX_BUILD_32_BITS -m32)
+add_flags_if(LIBCXX_TARGET_TRIPLE "-target ${LIBCXX_TARGET_TRIPLE}")
+add_flags_if(LIBCXX_SYSROOT "--sysroot ${LIBCXX_SYSROOT}")
+add_flags_if(LIBCXX_GCC_TOOLCHAIN "-gcc-toolchain ${LIBCXX_GCC_TOOLCHAIN}")
+
+# Warning flags ===============================================================
+add_compile_flags_if_supported(
+    -Wall -W -Wwrite-strings
+    -Wno-unused-parameter -Wno-long-long
+    -Werror=return-type)
 if (LIBCXX_ENABLE_WERROR)
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WERROR_FLAG -Werror)
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WX_FLAG -WX)
-else()
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_WNO_ERROR_FLAG -Wno-error)
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_NO_WX_FLAG -WX-)
+  add_compile_flags_if_supported(-Werror)
+  add_compile_flags_if_supported(-WX)
 endif()
 if (LIBCXX_ENABLE_PEDANTIC)
-  append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_PEDANTIC_FLAG -pedantic)
+  add_compile_flags_if_supported(-pedantic)
 endif()
 
-# Get feature flags.
-# Exceptions
+# Exception flags =============================================================
 if (LIBCXX_ENABLE_EXCEPTIONS)
   # Catches C++ exceptions only and tells the compiler to assume that extern C
   # functions never throw a C++ exception.
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_EHSC_FLAG -EHsc)
+  add_compile_flags_if_supported(-EHsc)
 else()
-  list(APPEND LIBCXX_CXX_FLAGS -D_LIBCPP_NO_EXCEPTIONS)
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_NO_EHS_FLAG -EHs-)
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_NO_EHA_FLAG -EHa-)
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_FNO_EXCEPTIONS_FLAG -fno-exceptions)
+  add_definitions(-D_LIBCPP_NO_EXCEPTIONS)
+  add_compile_flags_if_supported(-EHs- -EHa-)
+  add_compile_flags_if_supported(-fno-exceptions)
 endif()
-# RTTI
+
+# RTTI flags ==================================================================
 if (NOT LIBCXX_ENABLE_RTTI)
-  list(APPEND LIBCXX_CXX_FLAGS -D_LIBCPP_NO_RTTI)
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_NO_GR_FLAG -GR-)
-  append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_FNO_RTTI_FLAG -fno-rtti)
+  add_definitions(-D_LIBCPP_NO_RTTI)
+  add_compile_flags_if_supported(-GR-)
+  add_compile_flags_if_supported(-fno-rtti)
 endif()
-# Assert
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+
+# Assertion flags =============================================================
+define_if(LIBCXX_ENABLE_ASSERTIONS -UNDEBUG)
+define_if_not(LIBCXX_ENABLE_ASSERTIONS -DNDEBUG)
 if (LIBCXX_ENABLE_ASSERTIONS)
   # MSVC doesn't like _DEBUG on release builds. See PR 4379.
-  if (NOT MSVC)
-    list(APPEND LIBCXX_COMPILE_FLAGS -D_DEBUG)
-  endif()
-  # On Release builds cmake automatically defines NDEBUG, so we
-  # explicitly undefine it:
-  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
-    list(APPEND LIBCXX_COMPILE_FLAGS -UNDEBUG)
-  endif()
-else()
-  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
-    list(APPEND LIBCXX_COMPILE_FLAGS -DNDEBUG)
-  endif()
-endif()
-# Static library
-if (NOT LIBCXX_ENABLE_SHARED)
-  list(APPEND LIBCXX_COMPILE_FLAGS -D_LIBCPP_BUILD_STATIC)
+  define_if_not(MSVC -D_DEBUG)
 endif()
 
-if (CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32)
-  if (LIBCXX_BUILD_32_BITS)
-    message(STATUS "Building 32 bits executables and libraries.")
-    list(APPEND LIBCXX_CXX_FLAGS "-m32")
-  endif()
-elseif(LIBCXX_BUILD_32_BITS)
-  message(FATAL_ERROR "LIBCXX_BUILD_32_BITS=ON is not supported on this platform.")
-endif()
-# This is the _ONLY_ place where add_definitions is called.
-if (MSVC)
-  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
-endif()
-
-# LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE configuration
-if (NOT LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE)
-  add_definitions(-D_LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
-endif()
-
-# LIBCXX_ENABLE_STDIN configuration
-if (NOT LIBCXX_ENABLE_STDIN)
-  add_definitions(-D_LIBCPP_HAS_NO_STDIN)
-endif()
-
-# LIBCXX_ENABLE_STDOUT configuration
-if (NOT LIBCXX_ENABLE_STDOUT)
-  add_definitions(-D_LIBCPP_HAS_NO_STDOUT)
-endif()
-
-# LIBCXX_ENABLE_THREADS configuration
-if (NOT LIBCXX_ENABLE_THREADS)
-  add_definitions(-D_LIBCPP_HAS_NO_THREADS)
-  if (NOT LIBCXX_ENABLE_MONOTONIC_CLOCK)
-    add_definitions(-D_LIBCPP_HAS_NO_MONOTONIC_CLOCK)
-  endif()
-# Ensure LIBCXX_ENABLE_MONOTONIC_CLOCK is set to ON.
-elseif(NOT LIBCXX_ENABLE_MONOTONIC_CLOCK)
-  message(FATAL_ERROR "LIBCXX_ENABLE_MONOTONIC_CLOCK can only be set to OFF"
-                      " when LIBCXX_ENABLE_THREADS is also set to OFF.")
-endif()
-
-# LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS configuration
-if (NOT LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS)
-  add_definitions(-D_LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS)
-endif()
-
-# Configure for sanitizers. If LIBCXX_BUILT_STANDALONE then we have to do
-# the flag translation ourselves. Othewise LLVM's CMakeList.txt will handle it.
-if (LIBCXX_BUILT_STANDALONE)
-  # NOTE: LLVM_USE_SANITIZER checks for a UNIX like system instead of MSVC.
-  # But we don't have LLVM_ON_UNIX so checking for MSVC is the best we can do.
-  if (LLVM_USE_SANITIZER AND NOT MSVC)
-    append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_FNO_OMIT_FRAME_POINTER_FLAG
-              "-fno-omit-frame-pointer")
-    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
-        NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
-      append_if(LIBCXX_CXX_FLAGS LIBCXX_HAS_GLINE_TABLES_ONLY_FLAG
-                "-gline-tables-only")
-    endif()
-    if (LLVM_USE_SANITIZER STREQUAL "Address")
-      list(APPEND LIBCXX_CXX_FLAGS "-fsanitize=address")
-    elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
-      list(APPEND LIBCXX_CXX_FLAGS "-fsanitize=memory")
-      if (LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
-        list(APPEND LIBCXX_CXX_FLAGS "-fsanitize-memory-track-origins")
-      endif()
-    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
-      list(APPEND LIBCXX_CXX_FLAGS
-          "-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover")
-    elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
-      list(APPEND LIBCXX_CXX_FLAGS "-fsanitize=thread")
-    else()
-      message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
-    endif()
-  elseif(MSVC)
-    message(WARNING "LLVM_USE_SANITIZER is not supported with MSVC")
-  endif()
-endif()
-
-append_if(LIBCXX_CXX_FLAGS LIBCXX_TARGET_TRIPLE
-          "-target ${LIBCXX_TARGET_TRIPLE}")
-
-append_if(LIBCXX_CXX_FLAGS LIBCXX_SYSROOT "--sysroot ${LIBCXX_SYSROOT}")
-append_if(LIBCXX_CXX_FLAGS LIBCXX_GCC_TOOLCHAIN
-          "-gcc-toolchain ${LIBCXX_GCC_TOOLCHAIN}")
-
-if (LLVM_USE_SANITIZER AND LIBCXX_GENERATE_COVERAGE)
-  message(FATAL_ERROR "LLVM_USE_SANITIZER cannot be used with LIBCXX_GENERATE_COVERAGE")
-endif()
-
-string(REPLACE ";" " " LIBCXX_CXX_FLAGS "${LIBCXX_CXX_FLAGS}")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LIBCXX_CXX_FLAGS}")
+# Feature flags ===============================================================
+define_if(MSVC -D_CRT_SECURE_NO_WARNINGS)
+define_if_not(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE -D_LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
+define_if_not(LIBCXX_ENABLE_STDIN -D_LIBCPP_HAS_NO_STDIN)
+define_if_not(LIBCXX_ENABLE_STDOUT -D_LIBCPP_HAS_NO_STDOUT)
+define_if_not(LIBCXX_ENABLE_THREADS -D_LIBCPP_HAS_NO_THREADS)
+define_if_not(LIBCXX_ENABLE_MONOTONIC_CLOCK -D_LIBCPP_HAS_NO_MONOTONIC_CLOCK)
+define_if_not(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS -D_LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS)
 
 #===============================================================================
-# Setup Source Code
+# Setup Source Code And Tests
 #===============================================================================
-
 include_directories(include)
 add_subdirectory(include)
-
-# Add source code. This also contains all of the logic for deciding linker flags
-# soname, etc...
 add_subdirectory(lib)
-
-#===============================================================================
-# Setup Tests
-#===============================================================================
-
 add_subdirectory(test)

cmake/Modules/FindLLVM.cmake

+
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  # Rely on llvm-config.
+  set(CONFIG_OUTPUT)
+  find_program(LLVM_CONFIG "llvm-config")
+  if(DEFINED LLVM_PATH)
+    set(LLVM_INCLUDE_DIR ${LLVM_INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_PATH ${LLVM_PATH} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_MAIN_SRC_DIR ${LLVM_PATH})
+    set(LLVM_CMAKE_PATH "${LLVM_PATH}/cmake/modules")
+  elseif(LLVM_CONFIG)
+    message(STATUS "Found LLVM_CONFIG as ${LLVM_CONFIG}")
+    set(CONFIG_COMMAND ${LLVM_CONFIG}
+      "--includedir"
+      "--prefix"
+      "--src-root")
+    execute_process(
+      COMMAND ${CONFIG_COMMAND}
+      RESULT_VARIABLE HAD_ERROR
+      OUTPUT_VARIABLE CONFIG_OUTPUT
+    )
+    if(NOT HAD_ERROR)
+      string(REGEX REPLACE
+        "[ \t]*[\r\n]+[ \t]*" ";"
+        CONFIG_OUTPUT ${CONFIG_OUTPUT})
+    else()
+      string(REPLACE ";" " " CONFIG_COMMAND_STR "${CONFIG_COMMAND}")
+      message(STATUS "${CONFIG_COMMAND_STR}")
+      message(FATAL_ERROR "llvm-config failed with status ${HAD_ERROR}")
+    endif()
+
+    list(GET CONFIG_OUTPUT 0 INCLUDE_DIR)
+    list(GET CONFIG_OUTPUT 1 LLVM_OBJ_ROOT)
+    list(GET CONFIG_OUTPUT 2 MAIN_SRC_DIR)
+
+    set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
+    set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/share/llvm/cmake")
+  else()
+    message(FATAL_ERROR "llvm-config not found and LLVM_MAIN_SRC_DIR not defined. "
+                        "Reconfigure with -DLLVM_CONFIG=path/to/llvm-config "
+                        "or -DLLVM_PATH=path/to/llvm-source-root.")
+  endif()
+
+  if (NOT EXISTS ${LLVM_MAIN_SRC_DIR})
+    message(FATAL_ERROR "Not found: ${LLVM_MAIN_SRC_DIR}")
+  endif()
+
+  if(NOT EXISTS ${LLVM_CMAKE_PATH})
+    message(FATAL_ERROR "Not found: ${LLVM_CMAKE_PATH}")
+  endif()
+
+  list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")
+  list(APPEND CMAKE_MODULE_PATH "${LLVM_MAIN_SRC_DIR}/cmake/modules")
+
+
+  if(LLVM_LIT)
+    # Define the default arguments to use with 'lit', and an option for the user
+    # to override.
+    set(LIT_ARGS_DEFAULT "-sv --show-xfail --show-unsupported")
+    if (MSVC OR XCODE)
+      set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
+    endif()
+    set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
+
+    # On Win32 hosts, provide an option to specify the path to the GnuWin32 tools.
+    if( WIN32 AND NOT CYGWIN )
+      set(LLVM_LIT_TOOLS_DIR "" CACHE PATH "Path to GnuWin32 tools")
+    endif()
+  else()
+    set(LLVM_INCLUDE_TESTS OFF)
+  endif()
+
+  set(LIBCXX_BUILT_STANDALONE 1)
+else()
+  set(LLVM_MAIN_SRC_DIR "${CMAKE_SOURCE_DIR}" CACHE PATH "Path to LLVM source tree")
+  set(LLVM_LIT "${CMAKE_SOURCE_DIR}/utils/lit/lit.py")
+endif()

cmake/Modules/HandleLibCXXABI.cmake

 
 endmacro()
 
+# Setup the default options if LIBCXX_CXX_ABI is not specified.
+if (NOT LIBCXX_CXX_ABI)
+  if (NOT DEFINED LIBCXX_BUILT_STANDALONE AND
+      IS_DIRECTORY "${CMAKE_SOURCE_DIR}/projects/libcxxabi")
+    set(LIBCXX_CXX_ABI_LIBNAME "libcxxabi")
+    set(LIBCXX_CXX_ABI_INCLUDE_PATHS "${CMAKE_SOURCE_DIR}/projects/libcxxabi/include")
+    set(LIBCXX_CXX_ABI_INTREE 1)
+  else ()
+    set(LIBCXX_CXX_ABI_LIBNAME "none")
+  endif ()
+else ()
+  set(LIBCXX_CXX_ABI_LIBNAME "${LIBCXX_CXX_ABI}")
+endif ()
+
+# Configure based on the selected ABI library.
 if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++" OR
     "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libsupc++")
   set(_LIBSUPCXX_INCLUDE_FILES

cmake/Modules/HandleLibcxxFlags.cmake

+# HandleLibcxxFlags - A set of macros used to setup the flags used to compile
+# and link libc++. These macros add flags to the following CMake variables.
+# - LIBCXX_COMPILE_FLAGS: flags used to compile libc++
+# - LIBCXX_LINK_FLAGS: flags used to link libc++
+# - LIBCXX_LIBRARIES: libraries to link libc++ to.
+
+include(CheckCXXCompilerFlag)
+
+unset(add_flag_if_supported)
+
+# Mangle the name of a compiler flag into a valid CMake identifier.
+# Ex: --std=c++11 -> STD_EQ_CXX11
+macro(mangle_name str output)
+  string(STRIP "${str}" strippedStr)
+  string(REGEX REPLACE "^/" "" strippedStr "${strippedStr}")
+  string(REGEX REPLACE "^-+" "" strippedStr "${strippedStr}")
+  string(REGEX REPLACE "-+$" "" strippedStr "${strippedStr}")
+  string(REPLACE "-" "_" strippedStr "${strippedStr}")
+  string(REPLACE "=" "_EQ_" strippedStr "${strippedStr}")
+  string(REPLACE "+" "X" strippedStr "${strippedStr}")
+  string(TOUPPER "${strippedStr}" ${output})
+endmacro()
+
+# Remove a list of flags from all CMake variables that affect compile flags.
+# This can be used to remove unwanted flags specified on the command line
+# or added in other parts of LLVM's cmake configuration.
+macro(remove_flags)
+  foreach(var ${ARGN})
+    string(REPLACE "${var}" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_SHARED_MODULE_FLAGS "${CMAKE_SHARED_MODULE_FLAGS}")
+    remove_definitions(${var})
+  endforeach()
+endmacro(remove_flags)
+
+# Add a macro definition if condition is true.
+macro(define_if condition def)
+  if (${condition})
+    add_definitions(${def})
+  endif()
+endmacro()
+
+# Add a macro definition if condition is not true.
+macro(define_if_not condition def)
+  if (NOT ${condition})
+    add_definitions(${def})
+  endif()
+endmacro()
+
+# Add a specified list of flags to both 'LIBCXX_COMPILE_FLAGS' and
+# 'LIBCXX_LINK_FLAGS'.
+macro(add_flags)
+  foreach(value ${ARGN})
+    list(APPEND LIBCXX_COMPILE_FLAGS ${value})
+    list(APPEND LIBCXX_LINK_FLAGS ${value})
+  endforeach()
+endmacro()
+
+# If the specified 'condition' is true then add a list of flags to both
+# 'LIBCXX_COMPILE_FLAGS' and 'LIBCXX_LINK_FLAGS'.
+macro(add_flags_if condition)
+  if (${condition})
+    add_flags(${ARGN})
+  endif()
+endmacro()
+
+# Add each flag in the list to LIBCXX_COMPILE_FLAGS and LIBCXX_LINK_FLAGS
+# if that flag is supported by the current compiler.
+macro(add_flags_if_supported)
+  foreach(flag ${ARGN})
+      mangle_name("${flag}" flagname)
+      check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+      add_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of flags to 'LIBCXX_COMPILE_FLAGS'.
+macro(add_compile_flags)
+  foreach(f ${ARGN})
+    list(APPEND LIBCXX_COMPILE_FLAGS ${f})
+  endforeach()
+endmacro()
+
+# If 'condition' is true then add the specified list of flags to
+# 'LIBCXX_COMPILE_FLAGS'
+macro(add_compile_flags_if condition)
+  if (${condition})
+    add_compile_flags(${ARGN})
+  endif()
+endmacro()
+
+# For each specified flag, add that flag to 'LIBCXX_COMPILE_FLAGS' if the
+# flag is supported by the C++ compiler.
+macro(add_compile_flags_if_supported)
+  foreach(flag ${ARGN})
+      mangle_name("${flag}" flagname)
+      check_cxx_compiler_flag("-Werror ${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of flags to 'LIBCXX_LINK_FLAGS'.
+macro(add_link_flags)
+  foreach(f ${ARGN})
+    list(APPEND LIBCXX_LINK_FLAGS ${f})
+  endforeach()
+endmacro()
+
+# If 'condition' is true then add the specified list of flags to
+# 'LIBCXX_LINK_FLAGS'
+macro(add_link_flags_if condition)
+  if (${condition})
+    add_link_flags(${ARGN})
+  endif()
+endmacro()
+
+# For each specified flag, add that flag to 'LIBCXX_LINK_FLAGS' if the
+# flag is supported by the C++ compiler.
+macro(add_link_flags_if_supported)
+  foreach(flag ${ARGN})
+    mangle_name("${flag}" flagname)
+    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+    add_link_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of libraries or link flags to 'LIBCXX_LIBRARIES'.
+macro(add_library_flags)
+  foreach(lib ${ARGN})
+    list(APPEND LIBCXX_LIBRARIES ${lib})
+  endforeach()
+endmacro()
+
+# if 'condition' is true then add the specified list of libraries and flags
+# to 'LIBCXX_LIBRARIES'.
+macro(add_library_flags_if condition)
+  if(${condition})
+    add_library_flags(${ARGN})
+  endif()
+endmacro()
+
+# Turn a comma separated CMake list into a space separated string.
+macro(split_list listname)
+  string(REPLACE ";" " " ${listname} "${${listname}}")
+endmacro()

cmake/config-ix.cmake

 include(CheckCXXCompilerFlag)
 
 # Check compiler flags
-check_cxx_compiler_flag(-std=c++11              LIBCXX_HAS_STDCXX11_FLAG)
-check_cxx_compiler_flag(-std=c++1y              LIBCXX_HAS_STDCXX1Y_FLAG)
-check_cxx_compiler_flag(-fPIC                   LIBCXX_HAS_FPIC_FLAG)
-check_cxx_compiler_flag(-fno-omit-frame-pointer LIBCXX_HAS_FNO_OMIT_FRAME_POINTER_FLAG)
-check_cxx_compiler_flag(-nodefaultlibs          LIBCXX_HAS_NODEFAULTLIBS_FLAG)
-check_cxx_compiler_flag(-nostdinc++             LIBCXX_HAS_NOSTDINCXX_FLAG)
-check_cxx_compiler_flag(-Wall                   LIBCXX_HAS_WALL_FLAG)
-check_cxx_compiler_flag(-W                      LIBCXX_HAS_W_FLAG)
-check_cxx_compiler_flag(-Wno-unused-parameter   LIBCXX_HAS_WNO_UNUSED_PARAMETER_FLAG)
-check_cxx_compiler_flag(-Wwrite-strings         LIBCXX_HAS_WWRITE_STRINGS_FLAG)
-check_cxx_compiler_flag(-Wno-long-long          LIBCXX_HAS_WNO_LONG_LONG_FLAG)
-check_cxx_compiler_flag(-pedantic               LIBCXX_HAS_PEDANTIC_FLAG)
-check_cxx_compiler_flag(-Werror                 LIBCXX_HAS_WERROR_FLAG)
-check_cxx_compiler_flag(-Wno-error              LIBCXX_HAS_WNO_ERROR_FLAG)
-check_cxx_compiler_flag(-fno-exceptions         LIBCXX_HAS_FNO_EXCEPTIONS_FLAG)
-check_cxx_compiler_flag(-fno-rtti               LIBCXX_HAS_FNO_RTTI_FLAG)
-check_cxx_compiler_flag(-gline-tables-only      LIBCXX_HAS_GLINE_TABLES_ONLY_FLAG)
+
 check_cxx_compiler_flag(/WX                     LIBCXX_HAS_WX_FLAG)
 check_cxx_compiler_flag(/WX-                    LIBCXX_HAS_NO_WX_FLAG)
 check_cxx_compiler_flag(/EHsc                   LIBCXX_HAS_EHSC_FLAG)

 check_cxx_compiler_flag(/EHa-                   LIBCXX_HAS_NO_EHA_FLAG)
 check_cxx_compiler_flag(/GR-                    LIBCXX_HAS_NO_GR_FLAG)
 
+
 # Check libraries
 check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
 check_library_exists(c printf "" LIBCXX_HAS_C_LIB)

lib/CMakeLists.txt

 endif()
 
 if (LIBCXX_ENABLE_SHARED)
-  add_library(cxx SHARED
-    ${LIBCXX_SOURCES}
-    ${LIBCXX_HEADERS}
-    )
+  add_library(cxx SHARED ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
 else()
-  add_library(cxx STATIC
-    ${LIBCXX_SOURCES}
-    ${LIBCXX_HEADERS}
-    )
-endif()
-
-#if LIBCXX_CXX_ABI_LIBRARY_PATH is defined we want to add it to the search path.
-if (DEFINED LIBCXX_CXX_ABI_LIBRARY_PATH)
-  target_link_libraries(cxx "-L${LIBCXX_CXX_ABI_LIBRARY_PATH}")
+  add_library(cxx STATIC ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
 endif()
 
 if (DEFINED LIBCXX_CXX_ABI_DEPS)
   add_dependencies(cxx LIBCXX_CXX_ABI_DEPS)
 endif()
 
-set(libraries "")
-if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
-    # TODO(ericwf): Remove these GNU specific linker flags and let CMake do the
-    # configuration. This will be more portable.
-    list(APPEND libraries "-Wl,--whole-archive" "-Wl,-Bstatic")
-    list(APPEND libraries "${LIBCXX_CXX_ABI_LIBRARY}")
-    list(APPEND libraries "-Wl,-Bdynamic" "-Wl,--no-whole-archive")
-else()
-    list(APPEND libraries "${LIBCXX_CXX_ABI_LIBRARY}")
-endif()
+#if LIBCXX_CXX_ABI_LIBRARY_PATH is defined we want to add it to the search path.
+add_link_flags_if(LIBCXX_CXX_ABI_LIBRARY_PATH "-L${LIBCXX_CXX_ABI_LIBRARY_PATH}")
 
-# Generate library list.
-append_if(libraries LIBCXX_HAS_PTHREAD_LIB pthread)
-append_if(libraries LIBCXX_HAS_C_LIB c)
-append_if(libraries LIBCXX_HAS_M_LIB m)
-append_if(libraries LIBCXX_HAS_RT_LIB rt)
-append_if(libraries LIBCXX_HAS_GCC_S_LIB gcc_s)
+add_library_flags_if(LIBCXX_COVERAGE_LIBRARY "${LIBCXX_COVERAGE_LIBRARY}")
 
-if (LIBCXX_COVERAGE_LIBRARY)
-  target_link_libraries(cxx ${LIBCXX_COVERAGE_LIBRARY})
-endif()
-target_link_libraries(cxx ${libraries})
+add_library_flags_if(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "-Wl,--whole-archive" "-Wl,-Bstatic")
+add_library_flags("${LIBCXX_CXX_ABI_LIBRARY}")
+add_library_flags_if(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "-Wl,-Bdynamic" "-Wl,--no-whole-archive")
 
+# Generate library list.
+add_library_flags_if(LIBCXX_HAS_PTHREAD_LIB pthread)
+add_library_flags_if(LIBCXX_HAS_C_LIB c)
+add_library_flags_if(LIBCXX_HAS_M_LIB m)
+add_library_flags_if(LIBCXX_HAS_RT_LIB rt)
+add_library_flags_if(LIBCXX_HAS_GCC_S_LIB gcc_s)
 
 # Setup flags.
-append_if(LIBCXX_COMPILE_FLAGS LIBCXX_HAS_FPIC_FLAG -fPIC)
-append_if(LIBCXX_LINK_FLAGS LIBCXX_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
+add_flags_if_supported(-fPIC)
+add_link_flags_if_supported(-nodefaultlibs)
 
 if ( APPLE AND (LIBCXX_CXX_ABI_LIBNAME STREQUAL "libcxxabi" OR
                 LIBCXX_CXX_ABI_LIBNAME STREQUAL "none"))

   endif()
 
   if ( CMAKE_OSX_DEPLOYMENT_TARGET STREQUAL "10.6" )
-    list(APPEND LIBCXX_COMPILE_FLAGS "-U__STRICT_ANSI__")
-    list(APPEND LIBCXX_LINK_FLAGS
+    add_definitions(-D__STRICT_ANSI__)
+    add_link_flags(
       "-compatibility_version 1"
       "-current_version 1"
       "-install_name /usr/lib/libc++.1.dylib"

       set (OSX_RE_EXPORT_LINE "/usr/lib/libc++abi.dylib -Wl,-reexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/libc++abi${LIBCXX_LIBCPPABI_VERSION}.exp")
     endif()
 
-    list(APPEND LIBCXX_LINK_FLAGS
+    add_link_flags(
       "-compatibility_version 1"
       "-install_name /usr/lib/libc++.1.dylib"
       "-Wl,-unexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/libc++unexp.exp"

   endif()
 endif()
 
-string(REPLACE ";" " " LIBCXX_COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}")
-string(REPLACE ";" " " LIBCXX_LINK_FLAGS "${LIBCXX_LINK_FLAGS}")
+target_link_libraries(cxx ${LIBCXX_LIBRARIES})
+split_list(LIBCXX_COMPILE_FLAGS)
+split_list(LIBCXX_LINK_FLAGS)
 
 set_target_properties(cxx
   PROPERTIES

test/CMakeLists.txt

   endif()
 endmacro()
 
-set(LIT_EXECUTABLE "" CACHE FILEPATH "Path to LLVM's llvm-lit.")
-
-if(LIBCXX_BUILT_STANDALONE)
-  # Make sure we can use the console pool for recent cmake and ninja > 1.5
-  if(CMAKE_VERSION VERSION_LESS 3.1.20141117)
-    set(cmake_3_2_USES_TERMINAL)
-  else()
-    set(cmake_3_2_USES_TERMINAL USES_TERMINAL)
-  endif()
-else()
-  include(FindPythonInterp)
-  if(PYTHONINTERP_FOUND)
-    set(LIT_EXECUTABLE
-        ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/utils/lit/lit.py)
-  else()
-    message(WARNING "Could not find Python, cannot set LIT_EXECUTABLE.")
-  endif()
+set(LIBCXX_LIT_VARIANT "libcxx" CACHE STRING
+    "Configuration variant to use for LIT.")
+
+pythonize_bool(LIBCXX_ENABLE_EXCEPTIONS)
+pythonize_bool(LIBCXX_ENABLE_RTTI)
+pythonize_bool(LIBCXX_ENABLE_SHARED)
+pythonize_bool(LIBCXX_BUILD_32_BITS)
+pythonize_bool(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE)
+pythonize_bool(LIBCXX_ENABLE_STDIN)
+pythonize_bool(LIBCXX_ENABLE_STDOUT)
+pythonize_bool(LIBCXX_ENABLE_THREADS)
+pythonize_bool(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS)
+pythonize_bool(LIBCXX_ENABLE_MONOTONIC_CLOCK)
+pythonize_bool(LIBCXX_GENERATE_COVERAGE)
+pythonize_bool(LIBCXXABI_USE_LLVM_UNWINDER)
+
+# The tests shouldn't link to any ABI library when it has been linked into
+# libc++ statically.
+if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+  set(LIBCXX_CXX_ABI_LIBNAME "none")
 endif()
-
-if (LIT_EXECUTABLE)
-  set(LIT_ARGS_DEFAULT "-sv --show-unsupported --show-xfail")
-  if (MSVC OR XCODE)
-    set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
-  endif()
-  set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}"
-      CACHE STRING "Default options for lit")
-  set(LIT_ARGS "${LLVM_LIT_ARGS}")
-  separate_arguments(LIT_ARGS)
-
-  set(LIBCXX_LIT_VARIANT "libcxx" CACHE STRING
-      "Configuration variant to use for LIT.")
-
-  pythonize_bool(LIBCXX_ENABLE_EXCEPTIONS)
-  pythonize_bool(LIBCXX_ENABLE_RTTI)
-  pythonize_bool(LIBCXX_ENABLE_SHARED)
-  pythonize_bool(LIBCXX_BUILD_32_BITS)
-  pythonize_bool(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE)
-  pythonize_bool(LIBCXX_ENABLE_STDIN)
-  pythonize_bool(LIBCXX_ENABLE_STDOUT)
-  pythonize_bool(LIBCXX_ENABLE_THREADS)
-  pythonize_bool(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS)
-  pythonize_bool(LIBCXX_ENABLE_MONOTONIC_CLOCK)
-  pythonize_bool(LIBCXX_GENERATE_COVERAGE)
-  pythonize_bool(LIBCXXABI_USE_LLVM_UNWINDER)
-
-  # The tests shouldn't link to any ABI library when it has been linked into
-  # libc++ statically.
-  if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
-    set(LIBCXX_CXX_ABI_LIBNAME "none")
-  endif()
-  set(LIBCXX_TARGET_INFO "libcxx.test.target_info.LocalTI" CACHE STRING
-      "TargetInfo to use when setting up test environment.")
-  set(LIBCXX_EXECUTOR "None" CACHE STRING
-      "Executor to use when running tests.")
-
-  set(AUTO_GEN_COMMENT "## Autogenerated by libcxx configuration.\n# Do not edit!")
-
-  configure_file(
-    ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-    ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
-    @ONLY)
-
-  add_custom_target(check-libcxx
-    COMMAND ${LIT_EXECUTABLE}
-            ${LIT_ARGS}
-            ${CMAKE_CURRENT_BINARY_DIR}
-    DEPENDS cxx
-    COMMENT "Running libcxx tests"
-    ${cmake_3_2_USES_TERMINAL})
-
-  if (LIBCXX_GENERATE_COVERAGE)
-    include(CodeCoverage)
-    set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/coverage")
-    set(capture_dirs "${LIBCXX_LIB_CMAKEFILES_DIR}/cxx.dir/;${CMAKE_CURRENT_BINARY_DIR}")
-    set(extract_dirs "${LIBCXX_SOURCE_DIR}/include;${LIBCXX_SOURCE_DIR}/src")
-    setup_lcov_test_target_coverage("cxx" "${output_dir}" "${capture_dirs}" "${extract_dirs}")
-  endif()
-else()
-  message(WARNING
-          "LIT_EXECUTABLE not set, no check-libcxx target will be available!")
+set(LIBCXX_TARGET_INFO "libcxx.test.target_info.LocalTI" CACHE STRING
+    "TargetInfo to use when setting up test environment.")
+set(LIBCXX_EXECUTOR "None" CACHE STRING
+    "Executor to use when running tests.")
+
+set(AUTO_GEN_COMMENT "## Autogenerated by libcxx configuration.\n# Do not edit!")
+
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
+  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
+  @ONLY)
+
+add_lit_testsuite(check-libcxx "Running libcxx tests"
+  ${CMAKE_CURRENT_BINARY_DIR}
+  DEPENDS cxx)
+
+if (LIBCXX_GENERATE_COVERAGE)
+  include(CodeCoverage)
+  set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/coverage")
+  set(capture_dirs "${LIBCXX_LIB_CMAKEFILES_DIR}/cxx.dir/;${CMAKE_CURRENT_BINARY_DIR}")
+  set(extract_dirs "${LIBCXX_SOURCE_DIR}/include;${LIBCXX_SOURCE_DIR}/src")
+  setup_lcov_test_target_coverage("cxx" "${output_dir}" "${capture_dirs}" "${extract_dirs}")
 endif()
+

test/lit.site.cfg.in

 @AUTO_GEN_COMMENT@
 config.cxx_under_test           = "@LIBCXX_COMPILER@"
-config.std                      = "@LIBCXX_STD_VERSION@"
 config.libcxx_src_root          = "@LIBCXX_SOURCE_DIR@"
 config.libcxx_obj_root          = "@LIBCXX_BINARY_DIR@"
 config.cxx_library_root         = "@LIBCXX_LIBRARY_DIR@"

www/index.html

 
   <p>In-tree build:</p>
   <ul>
+    <li><code>cd where-you-want-to-live</code></li>
     <li>Check out libcxx and <a href="http://libcxxabi.llvm.org/">libcxxabi</a>
       into llvm/projects</li>
-    <li><code>cd llvm</code></li>
+    <li><code>cd where-you-want-to-build</code></li>
     <li><code>mkdir build &amp;&amp; cd build</code></li>
-    <li><code>cmake .. # Linux may require -DCMAKE_C_COMPILER=clang
+    <li><code>cmake path/to/llvm # Linux may require -DCMAKE_C_COMPILER=clang
         -DCMAKE_CXX_COMPILER=clang++</code></li>
     <li><code>make cxx</code></li>
   </ul>
 
-  <p>Out-of-tree build:</p>
+  <p>Out-of-tree buildc:</p>
   <ul>
-    <li>Check out libcxx</li>
+    <li><code>cd where-you-want-to-live</code></li>
+    <li>Check out libcxx and llvm</li>
     <li>If not on a Mac, also check out
       <a href="http://libcxxabi.llvm.org/">libcxxabi</a></li>
-    <li><code>cd libcxx</code></li>
+    <li><code>cd where-you-want-to-build</code></li>
     <li><code>mkdir build &amp;&amp; cd build</code></li>
-    <li><code>cmake -DLIBCXX_CXX_ABI=libcxxabi
+    <li><code>cmake -DLLVM_PATH=path/to/llvm
+        -DLIBCXX_CXX_ABI=libcxxabi
         -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
-        -DLIT_EXECUTABLE=path/to/llvm/utils/lit/lit.py .. # Linux may require
-        -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li>
+        -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
+        path/to/libcxx
+    </code></li>
     <li><code>make</code></li>
   </ul>