include(CheckCXXCompilerFlag)
include(CheckLibraryExists)
include(CheckSymbolExists)

# CodeGen options.
check_cxx_compiler_flag(-fPIC                COMPILER_RT_HAS_FPIC_FLAG)
check_cxx_compiler_flag(-fPIE                COMPILER_RT_HAS_FPIE_FLAG)
check_cxx_compiler_flag(-fno-builtin         COMPILER_RT_HAS_FNO_BUILTIN_FLAG)
check_cxx_compiler_flag(-fno-exceptions      COMPILER_RT_HAS_FNO_EXCEPTIONS_FLAG)
check_cxx_compiler_flag(-fomit-frame-pointer COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG)
check_cxx_compiler_flag(-funwind-tables      COMPILER_RT_HAS_FUNWIND_TABLES_FLAG)
check_cxx_compiler_flag(-fno-stack-protector COMPILER_RT_HAS_FNO_STACK_PROTECTOR_FLAG)
check_cxx_compiler_flag(-fvisibility=hidden  COMPILER_RT_HAS_FVISIBILITY_HIDDEN_FLAG)
check_cxx_compiler_flag(-fno-rtti            COMPILER_RT_HAS_FNO_RTTI_FLAG)
check_cxx_compiler_flag(-ffreestanding       COMPILER_RT_HAS_FFREESTANDING_FLAG)
check_cxx_compiler_flag("-Werror -fno-function-sections" COMPILER_RT_HAS_FNO_FUNCTION_SECTIONS_FLAG)
check_cxx_compiler_flag(-std=c++11           COMPILER_RT_HAS_STD_CXX11_FLAG)
check_cxx_compiler_flag(-ftls-model=initial-exec COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC)

check_cxx_compiler_flag(/GR COMPILER_RT_HAS_GR_FLAG)
check_cxx_compiler_flag(/GS COMPILER_RT_HAS_GS_FLAG)
check_cxx_compiler_flag(/MT COMPILER_RT_HAS_MT_FLAG)
check_cxx_compiler_flag(/Oy COMPILER_RT_HAS_Oy_FLAG)

# Debug info flags.
check_cxx_compiler_flag(-gline-tables-only COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG)
check_cxx_compiler_flag(-g COMPILER_RT_HAS_G_FLAG)
check_cxx_compiler_flag(/Zi COMPILER_RT_HAS_Zi_FLAG)
 
# Warnings.
check_cxx_compiler_flag(-Wall COMPILER_RT_HAS_WALL_FLAG)
check_cxx_compiler_flag(-Werror COMPILER_RT_HAS_WERROR_FLAG)
check_cxx_compiler_flag("-Werror -Wframe-larger-than=512" COMPILER_RT_HAS_WFRAME_LARGER_THAN_FLAG)
check_cxx_compiler_flag("-Werror -Wglobal-constructors"   COMPILER_RT_HAS_WGLOBAL_CONSTRUCTORS_FLAG)
check_cxx_compiler_flag("-Werror -Wc99-extensions"     COMPILER_RT_HAS_WC99_EXTENSIONS_FLAG)
check_cxx_compiler_flag("-Werror -Wgnu"                COMPILER_RT_HAS_WGNU_FLAG)
check_cxx_compiler_flag("-Werror -Wnon-virtual-dtor"   COMPILER_RT_HAS_WNON_VIRTUAL_DTOR_FLAG)
check_cxx_compiler_flag("-Werror -Wvariadic-macros"    COMPILER_RT_HAS_WVARIADIC_MACROS_FLAG)

check_cxx_compiler_flag(/W3 COMPILER_RT_HAS_W3_FLAG)
check_cxx_compiler_flag(/WX COMPILER_RT_HAS_WX_FLAG)
check_cxx_compiler_flag(/wd4146 COMPILER_RT_HAS_WD4146_FLAG)
check_cxx_compiler_flag(/wd4291 COMPILER_RT_HAS_WD4291_FLAG)
check_cxx_compiler_flag(/wd4391 COMPILER_RT_HAS_WD4391_FLAG)
check_cxx_compiler_flag(/wd4722 COMPILER_RT_HAS_WD4722_FLAG)
check_cxx_compiler_flag(/wd4800 COMPILER_RT_HAS_WD4800_FLAG)

# Symbols.
check_symbol_exists(__func__ "" COMPILER_RT_HAS_FUNC_SYMBOL)

# Libraries.
check_library_exists(c printf "" COMPILER_RT_HAS_LIBC)
check_library_exists(dl dlopen "" COMPILER_RT_HAS_LIBDL)
check_library_exists(m pow "" COMPILER_RT_HAS_LIBM)
check_library_exists(pthread pthread_create "" COMPILER_RT_HAS_LIBPTHREAD)
check_library_exists(stdc++ __cxa_throw "" COMPILER_RT_HAS_LIBSTDCXX)

# Architectures.

# List of all architectures we can target.
set(COMPILER_RT_SUPPORTED_ARCH)

# 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")

# test_target_arch(<arch> <target flags...>)
# Sets the target flags for a given architecture and determines if this
# architecture is supported by trying to build a simple file.
macro(test_target_arch arch)
  set(TARGET_${arch}_CFLAGS ${ARGN})
  set(argstring "${CMAKE_EXE_LINKER_FLAGS}")
  foreach(arg ${ARGN})
    set(argstring "${argstring} ${arg}")
  endforeach()
  try_compile(CAN_TARGET_${arch} ${CMAKE_BINARY_DIR} ${SIMPLE_SOURCE}
              COMPILE_DEFINITIONS "${TARGET_${arch}_CFLAGS}"
              OUTPUT_VARIABLE TARGET_${arch}_OUTPUT
              CMAKE_FLAGS "-DCMAKE_EXE_LINKER_FLAGS:STRING=${argstring}")
  if(${CAN_TARGET_${arch}})
    list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
  elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "${arch}")
    # 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()

# Add $arch as supported with no additional flags.
macro(add_default_target_arch arch)
  set(TARGET_${arch}_CFLAGS "")
  set(CAN_TARGET_${arch} 1)
  list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
endmacro()

macro(detect_target_arch)
  check_symbol_exists(__arm__ "" __ARM)
  check_symbol_exists(__aarch64__ "" __AARCH64)
  check_symbol_exists(__x86_64__ "" __X86_64)
  check_symbol_exists(__i686__ "" __I686)
  check_symbol_exists(__i386__ "" __I386)
  check_symbol_exists(__mips__ "" __MIPS)
  check_symbol_exists(__mips64__ "" __MIPS64)
  if(__ARM)
    add_default_target_arch(arm)
  elseif(__AARCH64)
    add_default_target_arch(aarch64)
  elseif(__X86_64)
    add_default_target_arch(x86_64)
  elseif(__I686)
    add_default_target_arch(i686)
  elseif(__I386)
    add_default_target_arch(i386)
  elseif(__MIPS64) # must be checked before __MIPS
    add_default_target_arch(mips64)
  elseif(__MIPS)
    add_default_target_arch(mips)
  endif()
endmacro()

# 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()
  if("${LLVM_NATIVE_ARCH}" STREQUAL "X86")
    if (NOT MSVC)
      test_target_arch(x86_64 ${TARGET_64_BIT_CFLAGS})
    endif()
    test_target_arch(i386 ${TARGET_32_BIT_CFLAGS})
  elseif("${LLVM_NATIVE_ARCH}" STREQUAL "PowerPC")
    test_target_arch(powerpc64 ${TARGET_64_BIT_CFLAGS})
    test_target_arch(powerpc64le ${TARGET_64_BIT_CFLAGS})
  elseif("${LLVM_NATIVE_ARCH}" STREQUAL "Mips")
    if("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "mipsel|mips64el")
      # regex for mipsel, mips64el
      test_target_arch(mipsel ${TARGET_32_BIT_CFLAGS})
      test_target_arch(mips64el ${TARGET_64_BIT_CFLAGS})
    else()
      test_target_arch(mips ${TARGET_32_BIT_CFLAGS})
      test_target_arch(mips64 ${TARGET_64_BIT_CFLAGS})
    endif()
  elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "arm")
    test_target_arch(arm "-march=armv7-a")
  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=aarch64")
  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)
  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()

# Arhcitectures supported by compiler-rt libraries.
filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
  x86_64 i386 i686 powerpc64 powerpc64le arm aarch64 mips mips64 mipsel mips64el)
filter_available_targets(ASAN_SUPPORTED_ARCH
  x86_64 i386 i686 powerpc64 powerpc64le arm mips mipsel mips64 mips64el)
filter_available_targets(DFSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
filter_available_targets(LSAN_SUPPORTED_ARCH x86_64)
# LSan 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(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)
filter_available_targets(UBSAN_SUPPORTED_ARCH x86_64 i386 i686 arm aarch64 mips mipsel)

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
    (OS_NAME MATCHES "Android|Darwin|Linux|FreeBSD" OR
    (OS_NAME MATCHES "Windows" AND MSVC AND CMAKE_SIZEOF_VOID_P EQUAL 4)))
  set(COMPILER_RT_HAS_SANITIZER_COMMON TRUE)
else()
  set(COMPILER_RT_HAS_SANITIZER_COMMON FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND ASAN_SUPPORTED_ARCH)
  set(COMPILER_RT_HAS_ASAN TRUE)
else()
  set(COMPILER_RT_HAS_ASAN FALSE)
endif()

# TODO: Add builtins support.

if (COMPILER_RT_HAS_SANITIZER_COMMON AND DFSAN_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Linux")
  set(COMPILER_RT_HAS_DFSAN TRUE)
else()
  set(COMPILER_RT_HAS_DFSAN FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND LSAN_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Darwin|Linux|FreeBSD")
  set(COMPILER_RT_HAS_LSAN TRUE)
else()
  set(COMPILER_RT_HAS_LSAN FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND LSAN_COMMON_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Android")
  set(COMPILER_RT_HAS_LSAN_COMMON TRUE)
else()
  set(COMPILER_RT_HAS_LSAN_COMMON FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND MSAN_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Linux")
  set(COMPILER_RT_HAS_MSAN TRUE)
else()
  set(COMPILER_RT_HAS_MSAN FALSE)
endif()

if (PROFILE_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Darwin|Linux|FreeBSD")
  set(COMPILER_RT_HAS_PROFILE TRUE)
else()
  set(COMPILER_RT_HAS_PROFILE FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND TSAN_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Linux|FreeBSD")
  set(COMPILER_RT_HAS_TSAN TRUE)
else()
  set(COMPILER_RT_HAS_TSAN FALSE)
endif()

if (COMPILER_RT_HAS_SANITIZER_COMMON AND UBSAN_SUPPORTED_ARCH AND
    OS_NAME MATCHES "Darwin|Linux|FreeBSD")
  set(COMPILER_RT_HAS_UBSAN TRUE)
else()
  set(COMPILER_RT_HAS_UBSAN FALSE)
endif()