[CMake] Support platform building builtins without a full toolchain

[beanz]

Summary

This patch adds support to building lib/builtins without a fully functioning toolchain. It allows you to bootstrap a cross-compiler, which previously couldn't be done with CMake.

This patch contains the following specific changes:

• Split builtin-specific code out of config-ix.cmake into builtin-config-ix.cmake
• Split some common CMake functionality needed by both builtins and sanitizers into base-config-ix.cmake
• Moved some macros and functions out of config-ix.cmake into more common places
• Added BuiltinTests.cmake which has some custom implementations of compiler testing that don't rely on having a functional liker or sysroot
• Made lib/builtins/CMakeLists.txt able to be a top-level CMake configuration

I realize this patch is quite large, and I can break parts of it apart. I wanted to present it as a monolithic piece so that the other changes make sense.

I have tested this on Darwin targeting embedded Darwin, and on FreeBSD x86_64 targeting FreeBSD AArch64.

[samsonov]

Thanks for doing this! Overall, I'm fine with the direction of this patch and it all makes sense.
I agree we have to introduce alternative and simple way to build "builtins" library for cross-compilation use cases w/o relying on valid working toolchain that is necessary for sanitizers.
Please do break this into a series of smaller patches: as I understand, many of them will just involve moving code around, splitting common configuration routines into separate files, etc.

Some issues/nits/suggestions that caught my eye as I skimmed through the patch.

CMakeLists.txt

270

Sink this include to the files which actually use smth. from AddLLVM? (test/CMakeLists.txt and unittest/CMakeLists.txt)?

cmake/Modules/BuiltinTests.cmake

2

This comment is wrong.

cmake/Modules/CompilerRTDarwinUtils.cmake

115

Why can't use the same TEST_COMPILE_ONLY variable as in test_target_arch, and merge this into darwin_test_archs instead?

cmake/base-config-ix.cmake

1

The comment is now irrelevant here: we actually set CMake version in a different place.

26

IIRC there were changes in these files recently: we've add COMPILER_RT_TEST_CXX_COMPILER, you might need to rebase.

74

Hm... do you think it's worth moving these architecture support checking to a yet another .cmake module?

84

Wait, are you using argstring at all in this branch?

cmake/config-ix.cmake

102

Looks like you've moved this macro to a different location, should it be deleted here now?

[beanz]

This morning I committed the first two broken out patches in this sequence. They are both NFC, and I took into account the feedback provided by @samsonov.

The commits are r261105 and r261108.

The first commit pushes the AddLLVM dependency down into the test CMakeLists so it is only included where explicitly needed. The second commit moves the definitions of some macros out of config-ix.cmake into CompilerRTUtils.

[beanz]

Abandoning this review.

The last two parts of this change are out for review as:
http://reviews.llvm.org/D19692
http://reviews.llvm.org/D19742

Thanks,
-Chris

CMakeLists.txt

else()
   # Use ${cmake_2_8_12_KEYWORD} intead of KEYWORD in target_link_libraries().
   set(cmake_2_8_12_INTERFACE INTERFACE)
   set(cmake_2_8_12_PRIVATE PRIVATE)
   if(POLICY CMP0022)
     cmake_policy(SET CMP0022 NEW) # automatic when 2.8.12 is required
   endif()
 endif()
 
-# Top level target used to build all compiler-rt libraries.
-add_custom_target(compiler-rt ALL)
+# Add path for custom compiler-rt modules.
+list(INSERT CMAKE_MODULE_PATH 0
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
+  )
+
+include(base-config-ix)
 
 option(COMPILER_RT_BUILD_BUILTINS "Build builtins" ON)
 mark_as_advanced(COMPILER_RT_BUILD_BUILTINS)
 option(COMPILER_RT_BUILD_SANITIZERS "Build sanitizers" ON)
 mark_as_advanced(COMPILER_RT_BUILD_SANITIZERS)
 
-if (NOT COMPILER_RT_STANDALONE_BUILD)
-  # Compute the Clang version from the LLVM version.
-  # FIXME: We should be able to reuse CLANG_VERSION variable calculated
-  #        in Clang cmake files, instead of copying the rules here.
-  string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
-         ${PACKAGE_VERSION})
-  # Setup the paths where compiler-rt runtimes and headers should be stored.
-  set(COMPILER_RT_OUTPUT_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION})
-  set(COMPILER_RT_EXEC_OUTPUT_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
-  set(COMPILER_RT_INSTALL_PATH lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION})
-  option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests."
-         ${LLVM_INCLUDE_TESTS})
- option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered"
-        ${LLVM_ENABLE_WERROR})
-  # Use just-built Clang to compile/link tests on all platforms, except for
-  # Windows where we need to use clang-cl instead.
-  if(NOT MSVC)
-    set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
-  else()
-    set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang.exe)
-  endif()
-else()
-  # Take output dir and install path from the user.
-  set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
-    "Path where built compiler-rt libraries should be stored.")
-  set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
-    "Path where built compiler-rt executables should be stored.")
-  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
-    "Path where built compiler-rt libraries should be installed.")
-  option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
-  option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
-  # Use a host compiler to compile/link tests.
-  set(COMPILER_RT_TEST_COMPILER ${CMAKE_C_COMPILER} CACHE PATH "Compiler to use for testing")
+if (COMPILER_RT_STANDALONE_BUILD)
 
   if (NOT LLVM_CONFIG_PATH)
     find_program(LLVM_CONFIG_PATH "llvm-config"
                  DOC "Path to llvm-config binary")
     if (NOT LLVM_CONFIG_PATH)
       message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
     endif()
   endif()
if (COMPILER_RT_STANDALONE_BUILD)
   # Define default arguments to lit.
   set(LIT_ARGS_DEFAULT "-sv")
   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")
 endif()
 
-if("${COMPILER_RT_TEST_COMPILER}" MATCHES "clang[+]*$")
-  set(COMPILER_RT_TEST_COMPILER_ID Clang)
-elseif("${COMPILER_RT_TEST_COMPILER}" MATCHES "clang.*.exe$")
-  set(COMPILER_RT_TEST_COMPILER_ID Clang)
-else()
-  set(COMPILER_RT_TEST_COMPILER_ID GNU)
-endif()
-
 set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${TARGET_TRIPLE} CACHE STRING
     "Default triple for which compiler-rt runtimes will be built.")
 if(DEFINED COMPILER_RT_TEST_TARGET_TRIPLE)
   # Backwards compatibility: this variable used to be called
   # COMPILER_RT_TEST_TARGET_TRIPLE.
   set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${COMPILER_RT_TEST_TARGET_TRIPLE})
 endif()
 
 string(REPLACE "-" ";" TARGET_TRIPLE_LIST ${COMPILER_RT_DEFAULT_TARGET_TRIPLE})
 list(GET TARGET_TRIPLE_LIST 0 COMPILER_RT_DEFAULT_TARGET_ARCH)
 list(GET TARGET_TRIPLE_LIST 1 COMPILER_RT_DEFAULT_TARGET_OS)
 list(GET TARGET_TRIPLE_LIST 2 COMPILER_RT_DEFAULT_TARGET_ABI)
 # Determine if test target triple is specified explicitly, and doesn't match the
 # default.
 if(NOT COMPILER_RT_DEFAULT_TARGET_TRIPLE STREQUAL TARGET_TRIPLE)
   set(COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE TRUE)
 else()
   set(COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE FALSE)
 endif()
-
-if ("${COMPILER_RT_DEFAULT_TARGET_ABI}" STREQUAL "androideabi")
-  set(ANDROID 1)
-endif()
-
-string(TOLOWER ${CMAKE_SYSTEM_NAME} COMPILER_RT_OS_DIR)
-set(COMPILER_RT_LIBRARY_OUTPUT_DIR
-  ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
-set(COMPILER_RT_LIBRARY_INSTALL_DIR
-  ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
-
-# Add path for custom compiler-rt modules.
-set(CMAKE_MODULE_PATH
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  ${CMAKE_MODULE_PATH}
-  )
 include(CompilerRTUtils)
 
 set(COMPILER_RT_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(COMPILER_RT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 # We support running instrumented tests when we're not cross compiling
 # and target a UNIX-like system or Windows.
 # We can run tests on Android even when we are cross-compiling.

 else()
   set(COMPILER_RT_HAS_LLD_SOURCES FALSE)
 endif()
 pythonize_bool(COMPILER_RT_HAS_LLD_SOURCES)
 
 add_subdirectory(lib)
 
 if(COMPILER_RT_INCLUDE_TESTS)
+  # Building the tests requires LLVM's CMake modules for lit support
+  include(AddLLVM)
   add_subdirectory(unittests)
   add_subdirectory(test)
 endif()

cmake/Modules/AddCompilerRT.cmake

-include(AddLLVM)
 include(ExternalProject)
 include(CompilerRTUtils)
 
 # Tries to add an "object library" target for a given list of OSs and/or
 # architectures with name "<name>.<arch>" for non-Darwin platforms if
 # architecture can be targeted, and "<name>.<os>" for Darwin platforms.
 # add_compiler_rt_object_libraries(<name>
 #                                  OS <os names>

cmake/Modules/BuiltinTests.cmake

+
+# This function takes an OS and a list of architectures and identifies the
+# subset of the architectures list that the installed toolchain can target.
+function(try_compile_only output)
+  set(SIMPLE_C ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/src.c)
+  file(WRITE ${SIMPLE_C} "int foo(int x, int y) { return x + y; }\n")
+
+  execute_process(
+    COMMAND ${CMAKE_C_COMPILER} ${CMAKE_C_FLAGS} "${ARGN}" -c ${SIMPLE_C}
+    RESULT_VARIABLE result
+    OUTPUT_VARIABLE TEST_OUTPUT
+    ERROR_VARIABLE TEST_ERROR
+  )
+  if(result EQUAL 0)
+    set(${output} True PARENT_SCOPE)
+  else()
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Testing compiler for supporting ${ARGN}:\n"
+        "${TEST_OUTPUT}\n${TEST_ERROR}\n")
+    set(${output} False PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(builtin_check_c_compiler_flag flag output)
+  message(STATUS "Performing Test ${output}")
+  try_compile_only(result ${flag})
+  set(${output} ${result} PARENT_SCOPE)
+  if(${result})
+    message(STATUS "Performing Test ${output} - Success")
+  else()
+    message(STATUS "Performing Test ${output} - Failed")
+  endif()
+endfunction()

cmake/Modules/CompilerRTDarwinUtils.cmake

+include(CMakeParseArguments)
+
 # On OS X SDKs can be installed anywhere on the base system and xcode-select can
 # set the default Xcode to use. This function finds the SDKs that are present in
 # the current Xcode.
 function(find_darwin_sdk_dir var sdk_name)
   # Let's first try the internal SDK, otherwise use the public SDK.
   execute_process(
     COMMAND xcodebuild -version -sdk ${sdk_name}.internal Path
     OUTPUT_VARIABLE var_internal
else()
         "Testing compiler for supporting ${os}-${arch}:\n"
         "${TEST_OUTPUT}\n")
     endif()
   endforeach()
   set(${valid_archs} ${working_archs}
     CACHE STRING "List of valid architectures for platform ${os}.")
 endfunction()
 
+# This function takes an OS and a list of architectures and identifies the
+# subset of the architectures list that the installed toolchain can target.
+# This variant of the function is specifically for generating builtin libraries
+# where we don't need a fully functioning sysroot.
+function(darwin_builtin_test_archs os valid_archs)
+  if(${valid_archs})
+    message(STATUS "Using cached valid architectures for ${os}.")
+    return()
+  endif()
+
+  set(archs ${ARGN})
+
+  # The simple program will build for x86_64h on the simulator because it is 
+  # compatible with x86_64 libraries (mostly), but since x86_64h isn't actually
+  # a valid or useful architecture for the iOS simulator we should drop it.
+  if(${os} STREQUAL "iossim")
+    list(REMOVE_ITEM archs "x86_64h")
+  endif()
+
+  set(working_archs)
+  foreach(arch ${archs})
+    set(arch_linker_flags "-arch ${arch} ${os_linker_flags}")
+    try_compile_only(CAN_TARGET_${os}_${arch} -v -arch ${arch} ${DARWIN_${os}_CFLAGS})
+    if(CAN_TARGET_${os}_${arch})
+      list(APPEND working_archs ${arch})
+    endif()
+  endforeach()
+  set(${valid_archs} ${working_archs} PARENT_SCOPE)
+endfunction()
+
 # This function checks the host cpusubtype to see if it is post-haswell. Haswell
 # and later machines can run x86_64h binaries. Haswell is cpusubtype 8.
 function(darwin_filter_host_archs input output)
   list_intersect(tmp_var DARWIN_osx_ARCHS ${input})
   execute_process(
     COMMAND sysctl hw.cpusubtype
     OUTPUT_VARIABLE SUBTYPE)
 

cmake/Modules/CompilerRTUtils.cmake

+include(CMakePushCheckState)
+include(CheckSymbolExists)
+
 # Because compiler-rt spends a lot of time setting up custom compile flags,
 # define a handy helper function for it. The compile flags setting in CMake
 # has serious issues that make its syntax challenging at best.
 function(set_target_compile_flags target)
   set(argstring "")
   foreach(arg ${ARGN})
     set(argstring "${argstring} ${arg}")
   endforeach()
macro(list_intersect output input1 input2)
   set(${output})
   foreach(it ${${input1}})
     list(FIND ${input2} ${it} index)
     if( NOT (index EQUAL -1))
       list(APPEND ${output} ${it})
     endif()
   endforeach()
 endmacro()
+
+# Takes ${ARGN} and puts only supported architectures in @out_var list.
+function(filter_available_targets out_var)
+  set(archs ${${out_var}})
+  foreach(arch ${ARGN})
+    list(FIND COMPILER_RT_SUPPORTED_ARCH ${arch} ARCH_INDEX)
+    if(NOT (ARCH_INDEX EQUAL -1) AND CAN_TARGET_${arch})
+      list(APPEND archs ${arch})
+    endif()
+  endforeach()
+  set(${out_var} ${archs} PARENT_SCOPE)
+endfunction()
+
+function(check_compile_definition def argstring out_var)
+  if("${def}" STREQUAL "")
+    set(${out_var} TRUE PARENT_SCOPE)
+    return()
+  endif()
+  cmake_push_check_state()
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${argstring}")
+  check_symbol_exists(${def} "" ${out_var})
+  cmake_pop_check_state()
+endfunction()
+
+

cmake/base-config-ix.cmake

+# The CompilerRT build system requires CMake version 2.8.8 or higher in order
+# to use its support for building convenience "libraries" as a collection of
+# .o files. This is particularly useful in producing larger, more complex
+# runtime libraries.
+
+# Top level target used to build all compiler-rt libraries.
+add_custom_target(compiler-rt ALL)
+
+if (NOT COMPILER_RT_STANDALONE_BUILD)
+  # Compute the Clang version from the LLVM version.
+  # FIXME: We should be able to reuse CLANG_VERSION variable calculated
+  #        in Clang cmake files, instead of copying the rules here.
+  string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+         ${PACKAGE_VERSION})
+  # Setup the paths where compiler-rt runtimes and headers should be stored.
+  set(COMPILER_RT_OUTPUT_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION})
+  set(COMPILER_RT_EXEC_OUTPUT_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+  set(COMPILER_RT_INSTALL_PATH lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION})
+  option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests."
+         ${LLVM_INCLUDE_TESTS})
+ option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered"
+        ${LLVM_ENABLE_WERROR})
+  # Use just-built Clang to compile/link tests on all platforms, except for
+  # Windows where we need to use clang-cl instead.
+  if(NOT MSVC)
+    set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
+  else()
+    set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang.exe)
+  endif()
+else()
+    # Take output dir and install path from the user.
+  set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
+    "Path where built compiler-rt libraries should be stored.")
+  set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
+    "Path where built compiler-rt executables should be stored.")
+  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
+    "Path where built compiler-rt libraries should be installed.")
+  option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
+  option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
+  # Use a host compiler to compile/link tests.
+  set(COMPILER_RT_TEST_COMPILER ${CMAKE_C_COMPILER} CACHE PATH "Compiler to use for testing")
+endif()
+
+if("${COMPILER_RT_TEST_COMPILER}" MATCHES "clang[+]*$")
+  set(COMPILER_RT_TEST_COMPILER_ID Clang)
+elseif("${COMPILER_RT_TEST_COMPILER}" MATCHES "clang.*.exe$")
+  set(COMPILER_RT_TEST_COMPILER_ID Clang)
+else()
+  set(COMPILER_RT_TEST_COMPILER_ID GNU)
+endif()
+
+if ("${COMPILER_RT_DEFAULT_TARGET_ABI}" STREQUAL "androideabi")
+  set(ANDROID 1)
+endif()
+
+string(TOLOWER ${CMAKE_SYSTEM_NAME} COMPILER_RT_OS_DIR)
+set(COMPILER_RT_LIBRARY_OUTPUT_DIR
+  ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
+set(COMPILER_RT_LIBRARY_INSTALL_DIR
+  ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
+
+if(APPLE)
+  option(COMPILER_RT_ENABLE_IOS "Enable building for iOS - Experimental" Off)
+  option(COMPILER_RT_ENABLE_WATCHOS "Enable building for watchOS - Experimental" Off)
+  option(COMPILER_RT_ENABLE_TVOS "Enable building for tvOS - Experimental" Off)
+endif()
+
+# test_target_arch(<arch> <def> <target flags...>)
+# Checks if architecture is supported: runs host compiler with provided
+# flags to verify that:
+#   1) <def> is defined (if non-empty)
+#   2) simple file can be successfully built.
+# If successful, saves target flags for this architecture.
+macro(test_target_arch arch def)
+  set(TARGET_${arch}_CFLAGS ${ARGN})
+  set(argstring "")
+  foreach(arg ${ARGN})
+    set(argstring "${argstring} ${arg}")
+  endforeach()
+  check_compile_definition("${def}" "${argstring}" HAS_${arch}_DEF)
+  if(NOT HAS_${arch}_DEF)
+    set(CAN_TARGET_${arch} FALSE)
+  elseif(TEST_COMPILE_ONLY)
+    set(argstring "${CMAKE_EXE_LINKER_FLAGS} ${argstring}")
+    try_compile_only(CAN_TARGET_${arch} ${TARGET_${arch}_CFLAGS})
+  else()
+    set(argstring "${CMAKE_EXE_LINKER_FLAGS} ${argstring}")
+    try_compile(CAN_TARGET_${arch} ${CMAKE_BINARY_DIR} ${SIMPLE_SOURCE}
+                COMPILE_DEFINITIONS "${TARGET_${arch}_CFLAGS}"
+                OUTPUT_VARIABLE TARGET_${arch}_OUTPUT
+                CMAKE_FLAGS "-DCMAKE_EXE_LINKER_FLAGS:STRING=${argstring}")
+  endif()
+  if(${CAN_TARGET_${arch}})
+    list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "${arch}" AND
+         COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE)
+    # Bail out if we cannot target the architecture we plan to test.
+    message(FATAL_ERROR "Cannot compile for ${arch}:\n${TARGET_${arch}_OUTPUT}")
+  endif()
+endmacro()
+
+macro(test_targets)
+  # Generate the COMPILER_RT_SUPPORTED_ARCH list.
+  if(ANDROID)
+    # Examine compiler output to determine target architecture.
+    detect_target_arch()
+    set(COMPILER_RT_OS_SUFFIX "-android")
+  elseif(NOT APPLE) # Supported archs for Apple platforms are generated later
+    if("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "i[2-6]86|x86|amd64")
+      if(NOT MSVC)
+        test_target_arch(x86_64 "" "-m64")
+        # FIXME: We build runtimes for both i686 and i386, as "clang -m32" may
+        # target different variant than "$CMAKE_C_COMPILER -m32". This part should
+        # be gone after we resolve PR14109.
+        test_target_arch(i686 __i686__ "-m32")
+        test_target_arch(i386 __i386__ "-m32")
+      else()
+        if (CMAKE_SIZEOF_VOID_P EQUAL 4)
+          test_target_arch(i386 "" "")
+        else()
+          test_target_arch(x86_64 "" "")
+        endif()
+      endif()
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "powerpc")
+      TEST_BIG_ENDIAN(HOST_IS_BIG_ENDIAN)
+      if(HOST_IS_BIG_ENDIAN)
+        test_target_arch(powerpc64 "" "-m64")
+      else()
+        test_target_arch(powerpc64le "" "-m64")
+      endif()
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "mipsel|mips64el")
+      # Gcc doesn't accept -m32/-m64 so we do the next best thing and use
+      # -mips32r2/-mips64r2. We don't use -mips1/-mips3 because we want to match
+      # clang's default CPU's. In the 64-bit case, we must also specify the ABI
+      # since the default ABI differs between gcc and clang.
+      # FIXME: Ideally, we would build the N32 library too.
+      test_target_arch(mipsel "" "-mips32r2" "--target=mipsel-linux-gnu")
+      test_target_arch(mips64el "" "-mips64r2" "--target=mips64el-linux-gnu" "-mabi=n64")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "mips")
+      test_target_arch(mips "" "-mips32r2" "--target=mips-linux-gnu")
+      test_target_arch(mips64 "" "-mips64r2" "--target=mips64-linux-gnu" "-mabi=n64")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "arm")
+      test_target_arch(arm "" "-march=armv7-a" "-mfloat-abi=soft" "-target=arm")
+      test_target_arch(armhf "" "-march=armv7-a" "-mfloat-abi=hard" "-target=arm")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "aarch32")
+      test_target_arch(aarch32 "" "-march=armv8-a" "-target" "arm")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "aarch64")
+      test_target_arch(aarch64 "" "-march=armv8-a" "-target" "aarch64")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "wasm32")
+      test_target_arch(wasm32 "" "--target=wasm32-unknown-unknown")
+    elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "wasm64")
+      test_target_arch(wasm64 "" "--target=wasm64-unknown-unknown")
+    endif()
+    set(COMPILER_RT_OS_SUFFIX "")
+  endif()
+endmacro()

cmake/builtin-config-ix.cmake

+include(BuiltinTests)
+
+builtin_check_c_compiler_flag(-fPIC                 COMPILER_RT_HAS_FPIC_FLAG)
+builtin_check_c_compiler_flag(-fPIE                 COMPILER_RT_HAS_FPIE_FLAG)
+builtin_check_c_compiler_flag(-fno-builtin          COMPILER_RT_HAS_FNO_BUILTIN_FLAG)
+builtin_check_c_compiler_flag(-std=c99              COMPILER_RT_HAS_STD_C99_FLAG)
+builtin_check_c_compiler_flag(-fvisibility=hidden   COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG)
+builtin_check_c_compiler_flag(-fomit-frame-pointer  COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG)
+builtin_check_c_compiler_flag(-ffreestanding        COMPILER_RT_HAS_FREESTANDING_FLAG)
+builtin_check_c_compiler_flag(-mfloat-abi=soft      COMPILER_RT_HAS_FLOAT_ABI_SOFT_FLAG)
+builtin_check_c_compiler_flag(-mfloat-abi=hard      COMPILER_RT_HAS_FLOAT_ABI_HARD_FLAG)
+builtin_check_c_compiler_flag(-static               COMPILER_RT_HAS_STATIC_FLAG)
+
+set(ARM64 aarch64)
+set(ARM32 arm armhf)
+set(X86 i386 i686)
+set(X86_64 x86_64)
+set(MIPS32 mips mipsel)
+set(MIPS64 mips64 mips64el)
+set(PPC64 powerpc64 powerpc64le)
+set(WASM32 wasm32)
+set(WASM64 wasm64)
+
+if(APPLE)
+  set(ARM64 arm64)
+  set(ARM32 armv7 armv7s)
+  set(X86_64 x86_64 x86_64h)
+endif()
+
+set(ALL_BUILTIN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
+    ${MIPS32} ${MIPS64} ${WASM32} ${WASM64})
+
+include(CompilerRTUtils)
+include(CompilerRTDarwinUtils)
+
+if(APPLE)
+  # On Darwin if /usr/include doesn't exist, the user probably has Xcode but not
+  # the command line tools. If this is the case, we need to find the OS X
+  # sysroot to pass to clang.
+  if(NOT EXISTS /usr/include)
+    execute_process(COMMAND xcodebuild -version -sdk macosx Path
+       OUTPUT_VARIABLE OSX_SYSROOT
+       ERROR_QUIET
+       OUTPUT_STRIP_TRAILING_WHITESPACE)
+    set(OSX_SYSROOT_FLAG "-isysroot${OSX_SYSROOT}")
+  endif()
+
+  option(COMPILER_RT_ENABLE_IOS "Enable building for iOS - Experimental" Off)
+  option(COMPILER_RT_ENABLE_WATCHOS "Enable building for watchOS - Experimental" Off)
+  option(COMPILER_RT_ENABLE_TVOS "Enable building for tvOS - Experimental" Off)
+
+  find_darwin_sdk_dir(DARWIN_osx_SYSROOT macosx)
+  find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
+  find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
+  find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
+  find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
+  find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
+  find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
+
+  set(DARWIN_EMBEDDED_PLATFORMS)
+
+  if(COMPILER_RT_ENABLE_IOS)
+    list(APPEND DARWIN_EMBEDDED_PLATFORMS ios)
+    set(DARWIN_ios_MIN_VER_FLAG -miphoneos-version-min)
+    set(DARWIN_ios_BUILTIN_MIN_VER 6.0)
+    set(DARWIN_ios_BUILTIN_MIN_VER_FLAG
+      ${DARWIN_ios_MIN_VER_FLAG}=${DARWIN_ios_BUILTIN_MIN_VER})
+  endif()
+  if(COMPILER_RT_ENABLE_WATCHOS)
+    list(APPEND DARWIN_EMBEDDED_PLATFORMS watchos)
+    set(DARWIN_watchos_MIN_VER_FLAG -mwatchos-version-min)
+    set(DARWIN_watchos_BUILTIN_MIN_VER 2.0)
+    set(DARWIN_watchos_BUILTIN_MIN_VER_FLAG
+      ${DARWIN_watchos_MIN_VER_FLAG}=${DARWIN_watchos_BUILTIN_MIN_VER})
+  endif()
+  if(COMPILER_RT_ENABLE_TVOS)
+    list(APPEND DARWIN_EMBEDDED_PLATFORMS tvos)
+    set(DARWIN_tvos_MIN_VER_FLAG -mtvos-version-min)
+    set(DARWIN_tvos_BUILTIN_MIN_VER 9.0)
+    set(DARWIN_tvos_BUILTIN_MIN_VER_FLAG
+      ${DARWIN_tvos_MIN_VER_FLAG}=${DARWIN_tvos_BUILTIN_MIN_VER})
+  endif()
+
+  set(BUILTIN_SUPPORTED_OS osx)
+
+  # We're setting the flag manually for each target OS
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "")
+
+  if(NOT DARWIN_osx_ARCHS)
+    set(DARWIN_osx_ARCHS i386 x86_64 x86_64h)
+  endif()
+
+  set(DARWIN_sim_ARCHS i386 x86_64)
+  set(DARWIN_device_ARCHS armv7 armv7s armv7k arm64)
+  
+  message(STATUS "OSX supported arches: ${DARWIN_osx_ARCHS}")
+  foreach(arch ${DARWIN_osx_ARCHS})
+    list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+    set(CAN_TARGET_${arch} 1)
+  endforeach()
+
+  # Need to build a 10.4 compatible libclang_rt
+  set(DARWIN_10.4_SYSROOT ${DARWIN_osx_SYSROOT})
+  set(DARWIN_10.4_BUILTIN_MIN_VER 10.4)
+  set(DARWIN_10.4_BUILTIN_MIN_VER_FLAG
+      -mmacosx-version-min=${DARWIN_10.4_BUILTIN_MIN_VER})
+  set(DARWIN_10.4_SKIP_CC_KEXT On)
+  darwin_builtin_test_archs(10.4 DARWIN_10.4_ARCHS i386 x86_64)
+  message(STATUS "OSX 10.4 supported builtin arches: ${DARWIN_10.4_ARCHS}")
+  if(DARWIN_10.4_ARCHS)
+    # don't include the Haswell slice in the 10.4 compatibility library
+    list(REMOVE_ITEM DARWIN_10.4_ARCHS x86_64h)
+    list(APPEND BUILTIN_SUPPORTED_OS 10.4)
+  endif()
+
+  foreach(platform ${DARWIN_EMBEDDED_PLATFORMS})
+
+    if(DARWIN_${platform}sim_SYSROOT)
+      set(DARWIN_${platform}sim_BUILTIN_MIN_VER
+        ${DARWIN_${platform}_BUILTIN_MIN_VER})
+      set(DARWIN_${platform}sim_BUILTIN_MIN_VER_FLAG
+        ${DARWIN_${platform}_BUILTIN_MIN_VER_FLAG})
+
+      set(DARWIN_${platform}sim_SKIP_CC_KEXT On)
+
+      set(test_arches ${DARWIN_sim_ARCHS})
+      if(DARWIN_${platform}sim_ARCHS)
+        set(test_arches DARWIN_${platform}sim_ARCHS)
+      endif()
+
+      darwin_builtin_test_archs(${platform}sim
+        DARWIN_${platform}sim_ARCHS
+        ${test_arches})
+      message(STATUS "${platform} Simulator supported builtin arches: ${DARWIN_${platform}sim_ARCHS}")
+      if(DARWIN_iossim_ARCHS)
+        list(APPEND BUILTIN_SUPPORTED_OS ${platform}sim)
+      endif()
+      foreach(arch ${DARWIN_${platform}sim_ARCHS})
+        list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+        set(CAN_TARGET_${arch} 1)
+      endforeach()
+    endif()
+
+    if(DARWIN_${platform}_SYSROOT)
+      set(test_arches ${DARWIN_device_ARCHS})
+      if(DARWIN_${platform}_ARCHS)
+        set(test_arches DARWIN_${platform}_ARCHS)
+      endif()
+
+      darwin_builtin_test_archs(${platform}
+        DARWIN_${platform}_ARCHS
+        ${test_arches})
+      message(STATUS "${platform} supported builtin arches: ${DARWIN_${platform}_ARCHS}")
+      if(DARWIN_${platform}_ARCHS)
+        list(APPEND BUILTIN_SUPPORTED_OS ${platform})
+      endif()
+      foreach(arch ${DARWIN_${platform}_ARCHS})
+        list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+        set(CAN_TARGET_${arch} 1)
+      endforeach()
+    endif()
+  endforeach()
+
+  # for list_intersect
+  include(CompilerRTUtils)
+
+  list_intersect(BUILTIN_SUPPORTED_ARCH ALL_BUILTIN_SUPPORTED_ARCH COMPILER_RT_SUPPORTED_ARCH)
+
+else()
+  # If we're not building the builtins standalone, just rely on the  tests in
+  # config-ix.cmake to tell us what to build. Otherwise we need to do some leg
+  # work here...
+  if(COMPILER_RT_BUILTINS_STANDALONE_BUILD)
+    set(TEST_COMPILE_ONLY On)
+    test_targets()
+  endif()
+  # Architectures supported by compiler-rt libraries.
+  filter_available_targets(BUILTIN_SUPPORTED_ARCH
+    ${ALL_BUILTIN_SUPPORTED_ARCH})
+endif()
+
+message(STATUS "Builtin supported architectures: ${BUILTIN_SUPPORTED_ARCH}")

cmake/config-ix.cmake

 
 # Try to compile a very simple source file to ensure we can target the given
 # platform. We use the results of these tests to build only the various target
 # runtime libraries supported by our current compilers cross-compiling
 # abilities.
 set(SIMPLE_SOURCE ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/simple.cc)
 file(WRITE ${SIMPLE_SOURCE} "#include <stdlib.h>\n#include <limits>\nint main() {}\n")
 
-function(check_compile_definition def argstring out_var)
-  if("${def}" STREQUAL "")
-    set(${out_var} TRUE PARENT_SCOPE)
-    return()
-  endif()
-  cmake_push_check_state()
-  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${argstring}")
-  check_symbol_exists(${def} "" ${out_var})
-  cmake_pop_check_state()
-endfunction()
-
 # test_target_arch(<arch> <def> <target flags...>)
 # Checks if architecture is supported: runs host compiler with provided
 # flags to verify that:
 #   1) <def> is defined (if non-empty)
 #   2) simple file can be successfully built.
 # If successful, saves target flags for this architecture.
 macro(test_target_arch arch def)
   set(TARGET_${arch}_CFLAGS ${ARGN})
   set(argstring "")
   foreach(arg ${ARGN})
     set(argstring "${argstring} ${arg}")
   endforeach()
   check_compile_definition("${def}" "${argstring}" HAS_${arch}_DEF)
   if(NOT HAS_${arch}_DEF)
     set(CAN_TARGET_${arch} FALSE)

 
 # Detect whether the current target platform is 32-bit or 64-bit, and setup
 # the correct commandline flags needed to attempt to target 32-bit and 64-bit.
 if (NOT CMAKE_SIZEOF_VOID_P EQUAL 4 AND
     NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
   message(FATAL_ERROR "Please use architecture with 4 or 8 byte pointers.")
 endif()
 
-# Generate the COMPILER_RT_SUPPORTED_ARCH list.
-if(ANDROID)
-  # Examine compiler output to determine target architecture.
-  detect_target_arch()
-  set(COMPILER_RT_OS_SUFFIX "-android")
-elseif(NOT APPLE) # Supported archs for Apple platforms are generated later
-  if("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "i[2-6]86|x86|amd64")
-    if(NOT MSVC)
-      test_target_arch(x86_64 "" "-m64")
-      # FIXME: We build runtimes for both i686 and i386, as "clang -m32" may
-      # target different variant than "$CMAKE_C_COMPILER -m32". This part should
-      # be gone after we resolve PR14109.
-      test_target_arch(i686 __i686__ "-m32")
-      test_target_arch(i386 __i386__ "-m32")
-    else()
-      if (CMAKE_SIZEOF_VOID_P EQUAL 4)
-        test_target_arch(i386 "" "")
-      else()
-        test_target_arch(x86_64 "" "")
-      endif()
-    endif()
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "powerpc")
-    TEST_BIG_ENDIAN(HOST_IS_BIG_ENDIAN)
-    if(HOST_IS_BIG_ENDIAN)
-      test_target_arch(powerpc64 "" "-m64")
-    else()
-      test_target_arch(powerpc64le "" "-m64")
-    endif()
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "mipsel|mips64el")
-    # Gcc doesn't accept -m32/-m64 so we do the next best thing and use
-    # -mips32r2/-mips64r2. We don't use -mips1/-mips3 because we want to match
-    # clang's default CPU's. In the 64-bit case, we must also specify the ABI
-    # since the default ABI differs between gcc and clang.
-    # FIXME: Ideally, we would build the N32 library too.
-    test_target_arch(mipsel "" "-mips32r2" "--target=mipsel-linux-gnu")
-    test_target_arch(mips64el "" "-mips64r2" "--target=mips64el-linux-gnu" "-mabi=n64")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "mips")
-    test_target_arch(mips "" "-mips32r2" "--target=mips-linux-gnu")
-    test_target_arch(mips64 "" "-mips64r2" "--target=mips64-linux-gnu" "-mabi=n64")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "arm")
-    test_target_arch(arm "" "-march=armv7-a" "-mfloat-abi=soft")
-    test_target_arch(armhf "" "-march=armv7-a" "-mfloat-abi=hard")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "aarch32")
-    test_target_arch(aarch32 "" "-march=armv8-a")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "aarch64")
-    test_target_arch(aarch64 "" "-march=armv8-a")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "wasm32")
-    test_target_arch(wasm32 "" "--target=wasm32-unknown-unknown")
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "wasm64")
-    test_target_arch(wasm64 "" "--target=wasm64-unknown-unknown")
-  endif()
-  set(COMPILER_RT_OS_SUFFIX "")
-endif()
-
-# Takes ${ARGN} and puts only supported architectures in @out_var list.
-function(filter_available_targets out_var)
-  set(archs ${${out_var}})
-  foreach(arch ${ARGN})
-    list(FIND COMPILER_RT_SUPPORTED_ARCH ${arch} ARCH_INDEX)
-    if(NOT (ARCH_INDEX EQUAL -1) AND CAN_TARGET_${arch})
-      list(APPEND archs ${arch})
-    endif()
-  endforeach()
-  set(${out_var} ${archs} PARENT_SCOPE)
-endfunction()
+test_targets()
 
 # Returns a list of architecture specific target cflags in @out_var list.
 function(get_target_flags_for_arch arch out_var)
   list(FIND COMPILER_RT_SUPPORTED_ARCH ${arch} ARCH_INDEX)
   if(ARCH_INDEX EQUAL -1)
     message(FATAL_ERROR "Unsupported architecture: ${arch}")
   else()
     if (NOT APPLE)

 set(WASM64 wasm64)
 
 if(APPLE)
   set(ARM64 arm64)
   set(ARM32 armv7 armv7s)
   set(X86_64 x86_64 x86_64h)
 endif()
 
-set(ALL_BUILTIN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
-    ${MIPS32} ${MIPS64} ${WASM32} ${WASM64})
 set(ALL_SANITIZER_COMMON_SUPPORTED_ARCH ${X86} ${X86_64} ${PPC64}
     ${ARM32} ${ARM64} ${MIPS32} ${MIPS64})
 set(ALL_ASAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
     ${MIPS32} ${MIPS64} ${PPC64})
 set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 set(ALL_LSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 set(ALL_MSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 set(ALL_PROFILE_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${PPC64}
if(APPLE)
   if(NOT EXISTS /usr/include)
     execute_process(COMMAND xcodebuild -version -sdk macosx Path
        OUTPUT_VARIABLE OSX_SYSROOT
        ERROR_QUIET
        OUTPUT_STRIP_TRAILING_WHITESPACE)
     set(OSX_SYSROOT_FLAG "-isysroot${OSX_SYSROOT}")
   endif()
 
-  option(COMPILER_RT_ENABLE_IOS "Enable building for iOS - Experimental" Off)
-  option(COMPILER_RT_ENABLE_WATCHOS "Enable building for watchOS - Experimental" Off)
-  option(COMPILER_RT_ENABLE_TVOS "Enable building for tvOS - Experimental" Off)
-
   find_darwin_sdk_dir(DARWIN_osx_SYSROOT macosx)
   find_darwin_sdk_dir(DARWIN_iossim_SYSROOT iphonesimulator)
   find_darwin_sdk_dir(DARWIN_ios_SYSROOT iphoneos)
   find_darwin_sdk_dir(DARWIN_watchossim_SYSROOT watchsimulator)
   find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
   find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
   find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
 
   if(COMPILER_RT_ENABLE_IOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS ios)
     set(DARWIN_ios_MIN_VER_FLAG -miphoneos-version-min)
     set(DARWIN_ios_SANITIZER_MIN_VER_FLAG
       ${DARWIN_ios_MIN_VER_FLAG}=7.0)
-    set(DARWIN_ios_BUILTIN_MIN_VER 6.0)
-    set(DARWIN_ios_BUILTIN_MIN_VER_FLAG
-      ${DARWIN_ios_MIN_VER_FLAG}=${DARWIN_ios_BUILTIN_MIN_VER})
   endif()
   if(COMPILER_RT_ENABLE_WATCHOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS watchos)
     set(DARWIN_watchos_MIN_VER_FLAG -mwatchos-version-min)
     set(DARWIN_watchos_SANITIZER_MIN_VER_FLAG
       ${DARWIN_watchos_MIN_VER_FLAG}=2.0)
-    set(DARWIN_watchos_BUILTIN_MIN_VER 2.0)
-    set(DARWIN_watchos_BUILTIN_MIN_VER_FLAG
-      ${DARWIN_watchos_MIN_VER_FLAG}=${DARWIN_watchos_BUILTIN_MIN_VER})
   endif()
   if(COMPILER_RT_ENABLE_TVOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS tvos)
     set(DARWIN_tvos_MIN_VER_FLAG -mtvos-version-min)
     set(DARWIN_tvos_SANITIZER_MIN_VER_FLAG
       ${DARWIN_tvos_MIN_VER_FLAG}=9.0)
-    set(DARWIN_tvos_BUILTIN_MIN_VER 9.0)
-    set(DARWIN_tvos_BUILTIN_MIN_VER_FLAG
-      ${DARWIN_tvos_MIN_VER_FLAG}=${DARWIN_tvos_BUILTIN_MIN_VER})
   endif()
 
   # Note: In order to target x86_64h on OS X the minimum deployment target must
   # be 10.8 or higher.
   set(SANITIZER_COMMON_SUPPORTED_OS osx)
-  set(BUILTIN_SUPPORTED_OS osx)
   set(PROFILE_SUPPORTED_OS osx)
   set(TSAN_SUPPORTED_OS osx)
   if(NOT SANITIZER_MIN_OSX_VERSION)
     string(REGEX MATCH "-mmacosx-version-min=([.0-9]+)"
            MACOSX_VERSION_MIN_FLAG "${CMAKE_CXX_FLAGS}")
     if(MACOSX_VERSION_MIN_FLAG)
       set(SANITIZER_MIN_OSX_VERSION "${CMAKE_MATCH_1}")
     elseif(CMAKE_OSX_DEPLOYMENT_TARGET)
if(APPLE)
   endif()
 
   set(DARWIN_osx_CFLAGS
     ${DARWIN_COMMON_CFLAGS}
     -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION})
   set(DARWIN_osx_LINKFLAGS
     ${DARWIN_COMMON_LINKFLAGS}
     -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION})
-  set(DARWIN_osx_BUILTIN_MIN_VER 10.5)
-  set(DARWIN_osx_BUILTIN_MIN_VER_FLAG
-      -mmacosx-version-min=${DARWIN_osx_BUILTIN_MIN_VER})
 
   if(DARWIN_osx_SYSROOT)
     list(APPEND DARWIN_osx_CFLAGS -isysroot ${DARWIN_osx_SYSROOT})
     list(APPEND DARWIN_osx_LINKFLAGS -isysroot ${DARWIN_osx_SYSROOT})
   endif()
 
   # Figure out which arches to use for each OS
   darwin_get_toolchain_supported_archs(toolchain_arches)
   message(STATUS "Toolchain supported arches: ${toolchain_arches}")
   
   if(NOT MACOSX_VERSION_MIN_FLAG)
     darwin_test_archs(osx
       DARWIN_osx_ARCHS
       ${toolchain_arches})
     message(STATUS "OSX supported arches: ${DARWIN_osx_ARCHS}")
     foreach(arch ${DARWIN_osx_ARCHS})
       list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
       set(CAN_TARGET_${arch} 1)
     endforeach()
 
-    # Need to build a 10.4 compatible libclang_rt
-    set(DARWIN_10.4_SYSROOT ${DARWIN_osx_SYSROOT})
-    set(DARWIN_10.4_BUILTIN_MIN_VER 10.4)
-    set(DARWIN_10.4_BUILTIN_MIN_VER_FLAG
-        -mmacosx-version-min=${DARWIN_10.4_BUILTIN_MIN_VER})
-    set(DARWIN_10.4_SKIP_CC_KEXT On)
-    darwin_test_archs(10.4
-      DARWIN_10.4_ARCHS
-      ${toolchain_arches})
-    message(STATUS "OSX 10.4 supported arches: ${DARWIN_10.4_ARCHS}")
-    if(DARWIN_10.4_ARCHS)
-      # don't include the Haswell slice in the 10.4 compatibility library
-      list(REMOVE_ITEM DARWIN_10.4_ARCHS x86_64h)
-      list(APPEND BUILTIN_SUPPORTED_OS 10.4)
-    endif()
-
     foreach(platform ${DARWIN_EMBEDDED_PLATFORMS})
       if(DARWIN_${platform}sim_SYSROOT)
         set(DARWIN_${platform}sim_CFLAGS
           ${DARWIN_COMMON_CFLAGS}
           ${DARWIN_${platform}_SANITIZER_MIN_VER_FLAG}
           -isysroot ${DARWIN_iossim_SYSROOT})
         set(DARWIN_${platform}sim_LINKFLAGS
           ${DARWIN_COMMON_LINKFLAGS}
           ${DARWIN_${platform}_SANITIZER_MIN_VER_FLAG}
           -isysroot ${DARWIN_${platform}sim_SYSROOT})
-        set(DARWIN_${platform}sim_BUILTIN_MIN_VER
-          ${DARWIN_${platform}_BUILTIN_MIN_VER})
-        set(DARWIN_${platform}sim_BUILTIN_MIN_VER_FLAG
-          ${DARWIN_${platform}_BUILTIN_MIN_VER_FLAG})
 
         set(DARWIN_${platform}sim_SKIP_CC_KEXT On)
         darwin_test_archs(${platform}sim
           DARWIN_${platform}sim_ARCHS
           ${toolchain_arches})
         message(STATUS "${platform} Simulator supported arches: ${DARWIN_${platform}sim_ARCHS}")
         if(DARWIN_iossim_ARCHS)
           list(APPEND SANITIZER_COMMON_SUPPORTED_OS ${platform}sim)
-          list(APPEND BUILTIN_SUPPORTED_OS ${platform}sim)
           list(APPEND PROFILE_SUPPORTED_OS ${platform}sim)
         endif()
         foreach(arch ${DARWIN_${platform}sim_ARCHS})
           list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
           set(CAN_TARGET_${arch} 1)
         endforeach()
       endif()
 
       if(DARWIN_${platform}_SYSROOT)
         set(DARWIN_${platform}_CFLAGS
           ${DARWIN_COMMON_CFLAGS}
           ${DARWIN_${platform}_SANITIZER_MIN_VER_FLAG}
           -isysroot ${DARWIN_${platform}_SYSROOT})
         set(DARWIN_${platform}_LINKFLAGS
           ${DARWIN_COMMON_LINKFLAGS}
           ${DARWIN_${platform}_SANITIZER_MIN_VER_FLAG}
           -isysroot ${DARWIN_${platform}_SYSROOT})
 
         darwin_test_archs(${platform}
           DARWIN_${platform}_ARCHS
           ${toolchain_arches})
         message(STATUS "${platform} supported arches: ${DARWIN_${platform}_ARCHS}")
         if(DARWIN_${platform}_ARCHS)
           list(APPEND SANITIZER_COMMON_SUPPORTED_OS ${platform})
-          list(APPEND BUILTIN_SUPPORTED_OS ${platform})
           list(APPEND PROFILE_SUPPORTED_OS ${platform})
         endif()
         foreach(arch ${DARWIN_${platform}_ARCHS})
           list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
           set(CAN_TARGET_${arch} 1)
         endforeach()
       endif()
     endforeach()
   endif()
 
   # for list_intersect
   include(CompilerRTUtils)
 
-  list_intersect(BUILTIN_SUPPORTED_ARCH ALL_BUILTIN_SUPPORTED_ARCH toolchain_arches)
 
   list_intersect(SANITIZER_COMMON_SUPPORTED_ARCH
     ALL_SANITIZER_COMMON_SUPPORTED_ARCH
     COMPILER_RT_SUPPORTED_ARCH
     )
   set(LSAN_COMMON_SUPPORTED_ARCH ${SANITIZER_COMMON_SUPPORTED_ARCH})
   set(UBSAN_COMMON_SUPPORTED_ARCH ${SANITIZER_COMMON_SUPPORTED_ARCH})
   list_intersect(ASAN_SUPPORTED_ARCH
if(APPLE)
   list_intersect(SAFESTACK_SUPPORTED_ARCH
     ALL_SAFESTACK_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
   list_intersect(CFI_SUPPORTED_ARCH
     ALL_CFI_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
 else()
   # Architectures supported by compiler-rt libraries.
-  filter_available_targets(BUILTIN_SUPPORTED_ARCH
-    ${ALL_BUILTIN_SUPPORTED_ARCH})
   filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
     ${ALL_SANITIZER_COMMON_SUPPORTED_ARCH})
   # LSan and UBSan common files should be available on all architectures
   # supported by other sanitizers (even if they build into dummy object files).
   filter_available_targets(LSAN_COMMON_SUPPORTED_ARCH
     ${SANITIZER_COMMON_SUPPORTED_ARCH})
   filter_available_targets(UBSAN_COMMON_SUPPORTED_ARCH
     ${SANITIZER_COMMON_SUPPORTED_ARCH})

lib/builtins/CMakeLists.txt

 # This directory contains a large amount of C code which provides
 # generic implementations of the core runtime library along with optimized
 # architecture-specific code in various subdirectories.
 
 # TODO: Need to add a mechanism for logging errors when builtin source files are
 # added to a sub-directory and not this CMakeLists file.
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  cmake_minimum_required(VERSION 3.2)
+
+  project(CompilerRTBuiltins C CXX ASM)
+  set(COMPILER_RT_STANDALONE_BUILD TRUE)
+  set(COMPILER_RT_BUILTINS_STANDALONE_BUILD TRUE)
+  list(INSERT CMAKE_MODULE_PATH 0
+    "${CMAKE_SOURCE_DIR}/../../cmake"
+    "${CMAKE_SOURCE_DIR}/../../cmake/Modules")
+  include(base-config-ix)
+  include(CompilerRTUtils)
+  if(APPLE)
+    include(CompilerRTDarwinUtils)
+  endif()
+  include(AddCompilerRT)
+endif()
+
+include(builtin-config-ix)
 
 set(GENERIC_SOURCES
   absvdi2.c
   absvsi2.c
   absvti2.c
   adddf3.c
   addsf3.c
   addtf3.c