[CMake] Add experimental support for building compiler-rt for iOS

[beanz]

Summary

This is a reunification of three separate reviews D11073, D11082, D11083.

Having them separate was not constructive even though the patches were smaller because it led to fragmented conversations, and this is really all about one change.

This patch incorporates feedback from samsonov, and refactors the hacky darwin code out of the root CMakeLists.txt and int config-ix.cmake.

[beanz]

Updating formatting based on Feedback from bogner.

[beanz]

samsonov, ping?

[beanz]

Fixing a bug I found this morning building with COMPILER_RT_ENABLE_IOS=Off (the default behavior). My code for filtering unsupported architectures wasn't quite right.

[filcab]

Minor nits and comments inline.
Thanks a lot for working on this!

cmake/Modules/CompilerRTDarwinUtils.cmake

31 ↗

(On Diff #31678)

Nit: Do we care about having the "LTO support" string?

63 ↗

(On Diff #31678)

"will build", but then you remove that arch?
Why is the iossim different from OS X, here?

65 ↗

(On Diff #31678)

Nit: You've consistently kept local variable all_lowercase except for this one.

cmake/config-ix.cmake

318 ↗

(On Diff #31678)

What's the behavior you want if MACOSX_VERSION_MIN_FLAG is set? I'm guessing you're going with "just assume the user just wants OS X, since they passed that flag in the CXX flags".
Shouldn't we at least test the OS X archs?

Why are we skipping iOS and iOS Simulator when we have a specific minimum OS X version? (I'm good with "so we don't change the user's CXX flags", but want to double-check)

335 ↗

(On Diff #31678)

Does clang not pass the proper flag to the linker for the iOS Simulator (when the flag below is passed)?
If not, are they both needed, still? Since clang should only be invoking the linker.
Why didn't we need this for OS X? Why are the versions slightly different?

357 ↗

(On Diff #31678)

Same as for iOS Simulator.

[beanz]

I'll send updated patches shortly. Comments inline below.

cmake/Modules/CompilerRTDarwinUtils.cmake

31 ↗

(On Diff #31678)

The "LTO Support" string is needed to escape the end of the regex. Since .* matches everything and nothing, and the behavior is to match as much as possible without the "LTO Support" string it matches the whole rest of the output.

I'm no regex expert though, so if you have a better suggestion I'm open.

63 ↗

(On Diff #31678)

I should explain better. The trivial test program does compile for x86_64h because it falls back to using the x86_64 libraries, but x86_64h isn't actually a valid simulator architecture, so other things will fail. I've had trouble finding a non-hacky way to make that detection work.

cmake/config-ix.cmake

318 ↗

(On Diff #31678)

The behavior if the user set macos-version-min explicitly is kinda complicated and probably broken. As it is now, I'm pretty sure we just don't build the sanitizers if you specify an explicit version min.

The rationale for skipping iOS and the simulator I assume is because we don't want to change the user's CXX flags, and there may be other incompatibilities. I don't know for sure though because that code exists in-tree today. This patch just moves it from the root CMakeLists.txt to config-ix as per samsonov's comments on previous reviews.

335 ↗

(On Diff #31678)

You're right. Since the driver should be passing this through we don't need it explicitly set.

[beanz]

Updates based on feedback from filcab.

[beanz]

Fixing regex as per filcab's suggestion.

[samsonov]

Sorry for the late response! This actually looks mostly good, I've got several minor comments.

cmake/Modules/AddCompilerRT.cmake

22 ↗

(On Diff #31720)

object library is just a collection of .o files. Why do you need link flags here?
(sorry if you've already replied me and I failed to notice it)

cmake/Modules/CompilerRTDarwinUtils.cmake

80 ↗

(On Diff #31720)

Please fix

cmake/Modules/CompilerRTUtils.cmake

66 ↗

(On Diff #31720)

Consider using

list(APPEND ${output} ${it})

cmake/config-ix.cmake

176 ↗

(On Diff #31720)

Consider replacing it with

elseif(NOT APPLE)

with a comment that COMPILER_RT_SUPPORTED_ARCH list for Apple platforms is generated below.

262 ↗

(On Diff #31720)

s/aarch64/${ARM64}

280 ↗

(On Diff #31720)

Looks like some part was lost in rebase. You need to put the block below under

if(NOT SANITIZER_MIN_OSX_VERSION)

so that the user can manually specify -DSANITIZER_MIN_OSX_VERSION at configure time (I was specifically asked to add this feature by Chromium folks).

(you might still look for MACOSX_VERSION_MIN_FLAG, because you're using it below).

380 ↗

(On Diff #31720)

Why not

list_union(ASAN_SUPPORTED_ARCH ALL_ASAN_SUPPORTED_ARCH SANITIZER_COMMON_SUPPORTED_ARCH)

?

[beanz]

Comments inline. Updated patches coming shortly.

cmake/Modules/AddCompilerRT.cmake

22 ↗

(On Diff #31720)

You are right. I will fix this.

cmake/Modules/CompilerRTUtils.cmake

66 ↗

(On Diff #31720)

You are right. I will fix this.

cmake/config-ix.cmake

176 ↗

(On Diff #31720)

Sure. I'll update this.

262 ↗

(On Diff #31720)

You are right. I will fix this.

280 ↗

(On Diff #31720)

You are right. I will fix this.

380 ↗

(On Diff #31720)

No particular reason. I will fix this.

[beanz]

Updates based on feedback from samsonov.

[samsonov]

OK, let's move this in, so that you can experiment with iOS build. Please watch linux/freebsd bots after commit. Thank you!

[beanz]

Thank you! I will land the patches shortly and watch the bots.

compiler-rt/trunk/CMakeLists.txt

 append_list_if(COMPILER_RT_HAS_WVARIADIC_MACROS_FLAG -Wno-variadic-macros SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WC99_EXTENSIONS_FLAG -Wno-c99-extensions SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WNON_VIRTUAL_DTOR_FLAG -Wno-non-virtual-dtor SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4146_FLAG /wd4146 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4291_FLAG /wd4291 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4391_FLAG /wd4391 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4722_FLAG /wd4722 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4800_FLAG /wd4800 SANITIZER_COMMON_CFLAGS)
-if(APPLE)
-  macro(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 ${var}
-      OUTPUT_STRIP_TRAILING_WHITESPACE
-      ERROR_FILE /dev/null
-    )
-    if(${var} STREQUAL "")
-      execute_process(
-        COMMAND xcodebuild -version -sdk ${sdk_name} Path
-        OUTPUT_VARIABLE ${var}
-        OUTPUT_STRIP_TRAILING_WHITESPACE
-        ERROR_FILE /dev/null
-      )
-    endif()
-  endmacro()
-
-  find_darwin_sdk_dir(OSX_SDK_DIR macosx)
-  find_darwin_sdk_dir(IOSSIM_SDK_DIR iphonesimulator)
-
-  set(SANITIZER_COMMON_SUPPORTED_OS osx)
-  if(NOT SANITIZER_MIN_OSX_VERSION)
-    string(REGEX MATCH "-mmacosx-version-min=([.0-9]+)"
-           MACOSX_VERSION_MIN_FLAG "${CMAKE_CXX_FLAGS}")
-    if(MACOSX_VERSION_MIN_FLAG)
-      set(SANITIZER_MIN_OSX_VERSION "${CMAKE_MATCH_1}")
-    elseif(CMAKE_OSX_DEPLOYMENT_TARGET)
-      set(SANITIZER_MIN_OSX_VERSION ${CMAKE_OSX_DEPLOYMENT_TARGET})
-    else()
-      set(SANITIZER_MIN_OSX_VERSION 10.9)
-      if(IOSSIM_SDK_DIR)
-        list(APPEND SANITIZER_COMMON_SUPPORTED_OS iossim)
-      endif()
-    endif()
-  endif()
-  if(SANITIZER_MIN_OSX_VERSION VERSION_LESS "10.7")
-    message(FATAL_ERROR "Too old OS X version: ${SANITIZER_MIN_OSX_VERSION}")
-  endif()
-
-  set(CMAKE_OSX_DEPLOYMENT_TARGET "") # We evaluate target OS X version above.
-  set(DARWIN_osx_CFLAGS -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION}
-    -stdlib=libc++)
-  set(DARWIN_iossim_CFLAGS
-    -stdlib=libc++
-    -mios-simulator-version-min=7.0 -isysroot ${IOSSIM_SDK_DIR})
-  set(DARWIN_osx_LINKFLAGS -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION}
-    -stdlib=libc++ -lc++ -lc++abi)
-  set(DARWIN_iossim_LINKFLAGS
-    -stdlib=libc++ -lc++ -lc++abi
-    -Wl,-ios_simulator_version_min,7.0.0
-    -mios-simulator-version-min=7.0
-    -isysroot ${IOSSIM_SDK_DIR})
-
-  if(OSX_SDK_DIR)
-    list(APPEND DARWIN_osx_CFLAGS -isysroot ${OSX_SDK_DIR})
-    list(APPEND DARWIN_osx_LINKFLAGS -isysroot ${OSX_SDK_DIR})
-  endif()
-endif()
 
 if(APPLE AND SANITIZER_MIN_OSX_VERSION VERSION_LESS "10.9")
   # Mac OS X prior to 10.9 had problems with exporting symbols from
   # libc++/libc++abi.
   set(SANITIZER_CAN_USE_CXXABI FALSE)
 else()
   set(SANITIZER_CAN_USE_CXXABI TRUE)
 endif()

compiler-rt/trunk/cmake/Modules/AddCompilerRT.cmake

 function(add_compiler_rt_object_libraries name)
   cmake_parse_arguments(LIB "" "" "OS;ARCHS;SOURCES;CFLAGS;DEFS" ${ARGN})
   set(libnames)
   if(APPLE)
     foreach(os ${LIB_OS})
       set(libname "${name}.${os}")
       set(libnames ${libnames} ${libname})
       set(extra_cflags_${libname} ${DARWIN_${os}_CFLAGS})
+      list_union(LIB_ARCHS_${libname} DARWIN_${os}_ARCHS LIB_ARCHS)
     endforeach()
   else()
     foreach(arch ${LIB_ARCHS})
       set(libname "${name}.${arch}")
       set(libnames ${libnames} ${libname})
       set(extra_cflags_${libname} ${TARGET_${arch}_CFLAGS})
       if(NOT CAN_TARGET_${arch})
         message(FATAL_ERROR "Architecture ${arch} can't be targeted")
         return()
       endif()
     endforeach()
   endif()
   
   foreach(libname ${libnames})
     add_library(${libname} OBJECT ${LIB_SOURCES})
     set_target_compile_flags(${libname}
       ${CMAKE_CXX_FLAGS} ${extra_cflags_${libname}} ${LIB_CFLAGS})
     set_property(TARGET ${libname} APPEND PROPERTY
       COMPILE_DEFINITIONS ${LIB_DEFS})
     if(APPLE)
-      set_target_properties(${libname} PROPERTIES OSX_ARCHITECTURES "${LIB_ARCHS}")
+      set_target_properties(${libname} PROPERTIES
+        OSX_ARCHITECTURES "${LIB_ARCHS_${libname}}")
     endif()
   endforeach()
 endfunction()
 
 # Adds static or shared runtime for a given architecture and puts it in the
 # proper directory in the build and install trees.
 # add_compiler_rt_runtime(<name> <arch> {STATIC,SHARED}
 #                         SOURCES <source files>

 #                                        LINKFLAGS <link flags>)
 macro(add_compiler_rt_darwin_dynamic_runtime name os)
   cmake_parse_arguments(LIB "" "" "ARCHS;SOURCES;CFLAGS;DEFS;LINKFLAGS" ${ARGN})
   add_library(${name} SHARED ${LIB_SOURCES})
   set_target_compile_flags(${name} ${LIB_CFLAGS} ${DARWIN_${os}_CFLAGS})
   set_target_link_flags(${name} ${LIB_LINKFLAGS} ${DARWIN_${os}_LINKFLAGS})
   set_property(TARGET ${name} APPEND PROPERTY
     COMPILE_DEFINITIONS ${LIB_DEFS})
+  list_union(filtered_arches DARWIN_${os}_ARCHS LIB_ARCHS)
   set_target_properties(${name} PROPERTIES
-    OSX_ARCHITECTURES "${LIB_ARCHS}"
+    OSX_ARCHITECTURES "${filtered_arches}"
     LIBRARY_OUTPUT_DIRECTORY ${COMPILER_RT_LIBRARY_OUTPUT_DIR})
   install(TARGETS ${name}
     LIBRARY DESTINATION ${COMPILER_RT_LIBRARY_INSTALL_DIR})
 endmacro()
 
 set(COMPILER_RT_TEST_CFLAGS)
 
 # Unittests support.

compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake

+# 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 ${sdk_name}.internal Path
+    OUTPUT_VARIABLE var_internal
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_FILE /dev/null
+  )
+  if("" STREQUAL "${var_internal}")
+    execute_process(
+      COMMAND xcodebuild -version -sdk ${sdk_name} Path
+      OUTPUT_VARIABLE var_internal
+      OUTPUT_STRIP_TRAILING_WHITESPACE
+      ERROR_FILE /dev/null
+    )
+  endif()
+  set(${var} ${var_internal} PARENT_SCOPE)
+endfunction()
+
+# There isn't a clear mapping of what architectures are supported with a given
+# target platform, but ld's version output does list the architectures it can
+# link for.
+function(darwin_get_toolchain_supported_archs output_var)
+  execute_process(
+    COMMAND ld -v
+    ERROR_VARIABLE LINKER_VERSION)
+
+  string(REGEX MATCH "configured to support archs: ([^\n]+)"
+         ARCHES_MATCHED "${LINKER_VERSION}")
+  if(ARCHES_MATCHED)
+    set(ARCHES "${CMAKE_MATCH_1}")
+    message("Matched ARCHES: ${ARCHES}")
+    string(REPLACE " " ";" ARCHES ${ARCHES})
+  else()
+    # If auto-detecting fails, fall back to a default set
+    message(WARNING "Detecting supported architectures from 'ld -v' failed. Returning default set.")
+    set(ARCHES "i386;x86_64;armv7;armv7s;arm64")
+  endif()
+  
+  set(${output_var} ${ARCHES} PARENT_SCOPE)
+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.
+function(darwin_test_archs os valid_archs)
+  set(archs ${ARGN})
+  message(STATUS "Finding valid architectures for ${os}...")
+  set(SIMPLE_CPP ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/src.cpp)
+  file(WRITE ${SIMPLE_CPP} "#include <iostream>\nint main() { return 0; }\n")
+
+  set(os_linker_flags)
+  foreach(flag ${DARWIN_${os}_LINKFLAGS})
+    set(os_linker_flags "${os_linker_flags} ${flag}")
+  endforeach()
+
+  # The simple program will build for x86_64h on the simulator because it is 
+  # compatible with x86_64 libraries (mostly), but since x86_64h isn't actually
+  # a valid or useful architecture for the iOS simulator we should drop it.
+  if(${os} STREQUAL "iossim")
+    list(REMOVE_ITEM archs "x86_64h")
+  endif()
+
+  set(working_archs)
+  foreach(arch ${archs})
+    
+    set(arch_linker_flags "-arch ${arch} ${os_linker_flags}")
+    try_compile(CAN_TARGET_${os}_${arch} ${CMAKE_BINARY_DIR} ${SIMPLE_CPP}
+                COMPILE_DEFINITIONS "-v -arch ${arch}" ${DARWIN_${os}_CFLAGS}
+                CMAKE_FLAGS "-DCMAKE_EXE_LINKER_FLAGS=${arch_linker_flags}"
+                OUTPUT_VARIABLE TEST_OUTPUT)
+    if(${CAN_TARGET_${os}_${arch}})
+      list(APPEND working_archs ${arch})
+    endif()
+  endforeach()
+  set(${valid_archs} ${working_archs} PARENT_SCOPE)
+endfunction()

compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake

 
 macro(append_have_file_definition filename varname list)
   check_include_file("${filename}" "${varname}")
   if (NOT ${varname})
     set("${varname}" 0)
   endif()
   list(APPEND ${list} "${varname}=${${varname}}")
 endmacro()
+
+macro(list_union 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()

compiler-rt/trunk/cmake/config-ix.cmake

 endif()
 
 # Generate the COMPILER_RT_SUPPORTED_ARCH list.
 if(ANDROID)
   # Can't rely on LLVM_NATIVE_ARCH in cross-compilation.
   # Examine compiler output instead.
   detect_target_arch()
   set(COMPILER_RT_OS_SUFFIX "-android")
-else()
+elseif(NOT APPLE) # Supported archs for Apple platforms are generated later
   if("${LLVM_NATIVE_ARCH}" STREQUAL "X86")
     if(NOT MSVC)
       test_target_arch(x86_64 "" "-m64")
       # FIXME: We build runtimes for both i686 and i386, as "clang -m32" may
       # target different variant than "$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")
elseif(NOT APPLE) # Supported archs for Apple platforms are generated later
   elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "aarch32")
     test_target_arch(aarch32 "" "-march=armv8-a")
   elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "aarch64")
     test_target_arch(aarch64 "" "-march=armv8-a")
   endif()
   set(COMPILER_RT_OS_SUFFIX "")
 endif()
 
-message(STATUS "Compiler-RT supported architectures: ${COMPILER_RT_SUPPORTED_ARCH}")
-
 # 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()
 
 # 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: ${arch}")
   else()
     set(${out_var} ${TARGET_${arch}_CFLAGS} PARENT_SCOPE)
   endif()
 endfunction()
 
+set(ARM64 aarch64)
+set(ARM32 arm)
+set(X86_64 x86_64)
+if(APPLE)
+  set(ARM64 arm64)
+  set(ARM32 armv7 armv7s)
+  set(X86_64 x86_64 x86_64h)
+endif()
+
+set(ALL_SANITIZER_COMMON_SUPPORTED_ARCH ${X86_64} i386 i686 powerpc64
+  powerpc64le ${ARM32} ${ARM64} mips mips64 mipsel mips64el)
+set(ALL_ASAN_SUPPORTED_ARCH ${X86_64} i386 i686 powerpc64 powerpc64le ${ARM32}
+  ${ARM64} mips mipsel mips64 mips64el)
+set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} mips64 mips64el ${ARM64})
+set(ALL_LSAN_SUPPORTED_ARCH ${X86_64} mips64 mips64el)
+set(ALL_MSAN_SUPPORTED_ARCH ${X86_64} mips64 mips64el)
+set(ALL_PROFILE_SUPPORTED_ARCH ${X86_64} i386 i686 ${ARM32} mips mips64
+    mipsel mips64el ${ARM64} powerpc64 powerpc64le)
+set(ALL_TSAN_SUPPORTED_ARCH ${X86_64} mips64 mips64el)
+set(ALL_UBSAN_SUPPORTED_ARCH ${X86_64} i386 i686 ${ARM32} ${ARM64} mips
+    mipsel mips64 mips64el powerpc64 powerpc64le)
+set(ALL_SAFESTACK_SUPPORTED_ARCH ${X86_64} i386 i686)
+
+if(APPLE)
+  include(CompilerRTDarwinUtils)
+
+  option(COMPILER_RT_ENABLE_IOS "Enable building for iOS - Experimental" Off)
+
+  find_darwin_sdk_dir(OSX_SDK_DIR macosx)
+  find_darwin_sdk_dir(IOSSIM_SDK_DIR iphonesimulator)
+  find_darwin_sdk_dir(IOS_SDK_DIR iphoneos)
+
+  # Note: In order to target x86_64h on OS X the minimum deployment target must
+  # be 10.8 or higher.
+  set(SANITIZER_COMMON_SUPPORTED_OS osx)
+  if(NOT SANITIZER_MIN_OSX_VERSION)
+    string(REGEX MATCH "-mmacosx-version-min=([.0-9]+)"
+           MACOSX_VERSION_MIN_FLAG "${CMAKE_CXX_FLAGS}")
+    if(MACOSX_VERSION_MIN_FLAG)
+      set(SANITIZER_MIN_OSX_VERSION "${CMAKE_MATCH_1}")
+    elseif(CMAKE_OSX_DEPLOYMENT_TARGET)
+      set(SANITIZER_MIN_OSX_VERSION ${CMAKE_OSX_DEPLOYMENT_TARGET})
+    else()
+      set(SANITIZER_MIN_OSX_VERSION 10.9)
+    endif()
+    if(SANITIZER_MIN_OSX_VERSION VERSION_LESS "10.7")
+      message(FATAL_ERROR "Too old OS X version: ${SANITIZER_MIN_OSX_VERSION}")
+    endif()
+  endif()
+
+  # We're setting the flag manually for each target OS
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "")
+  
+  set(DARWIN_COMMON_CFLAGS -stdlib=libc++)
+  set(DARWIN_COMMON_LINKFLAGS
+    -stdlib=libc++
+    -lc++
+    -lc++abi)
+  
+  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})
+
+  if(OSX_SDK_DIR)
+    list(APPEND DARWIN_osx_CFLAGS -isysroot ${OSX_SDK_DIR})
+    list(APPEND DARWIN_osx_LINKFLAGS -isysroot ${OSX_SDK_DIR})
+  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()
+
+    if(IOSSIM_SDK_DIR)
+      set(DARWIN_iossim_CFLAGS
+        ${DARWIN_COMMON_CFLAGS}
+        -mios-simulator-version-min=7.0
+        -isysroot ${IOSSIM_SDK_DIR})
+      set(DARWIN_iossim_LINKFLAGS
+        ${DARWIN_COMMON_LINKFLAGS}
+        -mios-simulator-version-min=7.0
+        -isysroot ${IOSSIM_SDK_DIR})
+
+      list(APPEND SANITIZER_COMMON_SUPPORTED_OS iossim)
+      darwin_test_archs(iossim
+        DARWIN_iossim_ARCHS
+        ${toolchain_arches})
+      message(STATUS "iOS Simulator supported arches: ${DARWIN_iossim_ARCHS}")
+      foreach(arch ${DARWIN_iossim_ARCHS})
+        list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+        set(CAN_TARGET_${arch} 1)
+      endforeach()
+    endif()
+
+    if(IOS_SDK_DIR AND COMPILER_RT_ENABLE_IOS)
+      set(DARWIN_ios_CFLAGS
+        ${DARWIN_COMMON_CFLAGS}
+        -miphoneos-version-min=7.0
+        -isysroot ${IOS_SDK_DIR})
+      set(DARWIN_ios_LINKFLAGS
+        ${DARWIN_COMMON_LINKFLAGS}
+        -miphoneos-version-min=7.0
+        -isysroot ${IOS_SDK_DIR})
+
+      list(APPEND SANITIZER_COMMON_SUPPORTED_OS ios)
+      darwin_test_archs(ios
+        DARWIN_ios_ARCHS
+        ${toolchain_arches})
+      message(STATUS "iOS supported arches: ${DARWIN_ios_ARCHS}")
+      foreach(arch ${DARWIN_ios_ARCHS})
+        list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
+        set(CAN_TARGET_${arch} 1)
+      endforeach()
+    endif()
+  endif()
+
+  # for list_union
+  include(CompilerRTUtils)
+
+  list_union(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_union(ASAN_SUPPORTED_ARCH
+    ALL_ASAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_union(DFSAN_SUPPORTED_ARCH
+    ALL_DFSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_union(LSAN_SUPPORTED_ARCH
+    ALL_LSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_union(MSAN_SUPPORTED_ARCH
+    ALL_MSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  # Note: profiles is only built for OS X
+  list_union(PROFILE_SUPPORTED_ARCH
+    ALL_PROFILE_SUPPORTED_ARCH
+    DARWIN_osx_ARCHS)
+  list_union(TSAN_SUPPORTED_ARCH
+    ALL_TSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_union(UBSAN_SUPPORTED_ARCH
+    ALL_UBSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_union(SAFESTACK_SUPPORTED_ARCH
+    ALL_SAFESTACK_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
+else()
   # Architectures supported by compiler-rt libraries.
   filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
-  x86_64 i386 i686 powerpc64 powerpc64le arm aarch64 mips mips64 mipsel mips64el)
-# LSan and UBSan common files should be available on all architectures supported
-# by other sanitizers (even if they build into dummy object files).
+    ${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})
-filter_available_targets(ASAN_SUPPORTED_ARCH
-  x86_64 i386 i686 powerpc64 powerpc64le arm mips mipsel mips64 mips64el aarch64)
-filter_available_targets(DFSAN_SUPPORTED_ARCH x86_64 mips64 mips64el aarch64)
-filter_available_targets(LSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
-filter_available_targets(MSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
-filter_available_targets(PROFILE_SUPPORTED_ARCH x86_64 i386 i686 arm mips mips64
-  mipsel mips64el aarch64 powerpc64 powerpc64le)
-filter_available_targets(TSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
-filter_available_targets(UBSAN_SUPPORTED_ARCH x86_64 i386 i686 arm aarch64 mips
-  mipsel mips64 mips64el powerpc64 powerpc64le)
-filter_available_targets(SAFESTACK_SUPPORTED_ARCH x86_64 i386 i686)
+  filter_available_targets(ASAN_SUPPORTED_ARCH ${ALL_ASAN_SUPPORTED_ARCH})
+  filter_available_targets(DFSAN_SUPPORTED_ARCH ${ALL_DFSAN_SUPPORTED_ARCH})
+  filter_available_targets(LSAN_SUPPORTED_ARCH ${ALL_LSAN_SUPPORTED_ARCH})
+  filter_available_targets(MSAN_SUPPORTED_ARCH ${ALL_MSAN_SUPPORTED_ARCH})
+  filter_available_targets(PROFILE_SUPPORTED_ARCH ${ALL_PROFILE_SUPPORTED_ARCH})
+  filter_available_targets(TSAN_SUPPORTED_ARCH ${ALL_TSAN_SUPPORTED_ARCH})
+  filter_available_targets(UBSAN_SUPPORTED_ARCH ${ALL_UBSAN_SUPPORTED_ARCH})
+  filter_available_targets(SAFESTACK_SUPPORTED_ARCH
+    ${ALL_SAFESTACK_SUPPORTED_ARCH})
+endif()
+
+message(STATUS "Compiler-RT supported architectures: ${COMPILER_RT_SUPPORTED_ARCH}")
 
 if(ANDROID)
   set(OS_NAME "Android")
 else()
   set(OS_NAME "${CMAKE_SYSTEM_NAME}")
 endif()
 
 if (SANITIZER_COMMON_SUPPORTED_ARCH AND NOT LLVM_USE_SANITIZER AND