clang.cmake

## Copyright 2009-2021 Intel Corporation
## SPDX-License-Identifier: Apache-2.0

MACRO(_SET_IF_EMPTY VAR VALUE)
  IF(NOT ${VAR})
    SET(${VAR} "${VALUE}")
  ENDIF()
ENDMACRO()

IF (EMBREE_ARM)
  IF ("x86_64" IN_LIST CMAKE_OSX_ARCHITECTURES)
    # set ARM an x86 flags for macOS universal binary build
    SET(FLAGS_SSE2 "-D__SSE__ -D__SSE2__ -msse -msse2 -mno-sse4.2")
    SET(FLAGS_SSE42 "-D__SSE4_2__  -D__SSE4_1__ -msse4.2")
    SET(FLAGS_AVX "-D__AVX__ -D__SSE4_2__  -D__SSE4_1__  -D__BMI__ -D__BMI2__ -D__LZCNT__ -mavx")
    SET(FLAGS_AVX2 "-D__AVX2__ -D__AVX__ -D__SSE4_2__  -D__SSE4_1__  -D__BMI__ -D__BMI2__ -D__LZCNT__ -mf16c -mavx2 -mfma -mlzcnt -mbmi -mbmi2")
    _SET_IF_EMPTY(FLAGS_AVX512 "-march=skx")
  ELSE ()
    SET(FLAGS_SSE2 "-D__SSE__ -D__SSE2__")
    SET(FLAGS_SSE42 "-D__SSE4_2__  -D__SSE4_1__")
    SET(FLAGS_AVX "-D__AVX__ -D__SSE4_2__  -D__SSE4_1__  -D__BMI__ -D__BMI2__ -D__LZCNT__")
    SET(FLAGS_AVX2 "-D__AVX2__ -D__AVX__ -D__SSE4_2__  -D__SSE4_1__  -D__BMI__ -D__BMI2__ -D__LZCNT__")
  ENDIF ()
ELSE ()
  # for `thread` keyword
  _SET_IF_EMPTY(FLAGS_SSE2  "-msse -msse2 -mno-sse4.2")
  _SET_IF_EMPTY(FLAGS_SSE42 "-msse4.2")
  _SET_IF_EMPTY(FLAGS_AVX   "-mavx")
  _SET_IF_EMPTY(FLAGS_AVX2  "-mf16c -mavx2 -mfma -mlzcnt -mbmi -mbmi2")
  _SET_IF_EMPTY(FLAGS_AVX512 "-march=skx")
ENDIF ()

IF (WIN32)

  SET(COMMON_CXX_FLAGS "")
  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /EHsc")        # catch C++ exceptions only and extern "C" functions never throw a C++ exception
#  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /MP")          # compile source files in parallel
  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /GR")          # enable runtime type information (on by default)
  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} -Xclang -fcxx-exceptions") # enable C++ exceptions in Clang
  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /w")          # disable all warnings
  SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /Gy")          # package individual functions
  IF (EMBREE_STACK_PROTECTOR)
    SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /GS")          # protects against return address overrides
  ELSE()
    SET(COMMON_CXX_FLAGS "${COMMON_CXX_FLAGS} /GS-")          # do not protect against return address overrides
  ENDIF()
  MACRO(DISABLE_STACK_PROTECTOR_FOR_FILE file)
    IF (EMBREE_STACK_PROTECTOR)
      SET_SOURCE_FILES_PROPERTIES(${file} PROPERTIES COMPILE_FLAGS "/GS-")
    ENDIF()
  ENDMACRO()
  
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${COMMON_CXX_FLAGS}")
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /DDEBUG")                     # enables assertions
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /DTBB_USE_DEBUG")             # configures TBB in debug mode
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Ox")                         # enable full optimizations
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Oi")                         # inline intrinsic functions
  SET(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} /DEBUG")        # generate debug information
  SET(CMAKE_SHARED_LINKER_FLAGS_DEBUG "${CMAKE_SHARED_LINKER_FLAGS_DEBUG} /DEBUG")  # generate debug information

  SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} ${COMMON_CXX_FLAGS}")
  SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /Ox")                       # enable full optimizations
  SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /Oi")                       # inline intrinsic functions
  
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} ${COMMON_CXX_FLAGS}")
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /Ox")                      # enable full optimizations
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /Oi")                      # inline intrinsic functions
  SET(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO} /DEBUG")        # generate debug information
  SET(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO} /DEBUG")  # generate debug information
  
  SET(SECURE_LINKER_FLAGS "")
  SET(SECURE_LINKER_FLAGS "${SECURE_LINKER_FLAGS} /NXCompat")    # compatible with data execution prevention (on by default)
  SET(SECURE_LINKER_FLAGS "${SECURE_LINKER_FLAGS} /DynamicBase") # random rebase of executable at load time
  IF (CMAKE_SIZEOF_VOID_P EQUAL 4)
    SET(SECURE_LINKER_FLAGS "${SECURE_LINKER_FLAGS} /SafeSEH")     # invoke known exception handlers (Win32 only, x64 exception handlers are safe by design)
  ENDIF()
  SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${SECURE_LINKER_FLAGS}")
  SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${SECURE_LINKER_FLAGS}")

  INCLUDE(msvc_post)
ELSE()

  OPTION(EMBREE_IGNORE_CMAKE_CXX_FLAGS "When enabled Embree ignores default CMAKE_CXX_FLAGS." ON)
  OPTION(EMBREE_ADDRESS_SANITIZER "Enabled CLANG address sanitizer." OFF)
  IF(EMBREE_IGNORE_CMAKE_CXX_FLAGS)
    IF(CMAKE_CXX_FLAGS)
      MESSAGE(WARNING "Ignoring CMAKE_CXX_FLAGS because EMBREE_IGNORE_CMAKE_CXX_FLAGS is enabled. Configure with -DEMBREE_IGNORE_CMAKE_CXX_FLAGS=OFF to honor CMAKE_CXX_FLAGS. Ignored value: '${CMAKE_CXX_FLAGS}'")
    ENDIF()
    SET(CMAKE_CXX_FLAGS "")
  ENDIF()

  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}") 
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")                       # enables most warnings
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wformat -Wformat-security")  # enables string format vulnerability warnings
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsigned-char")               # treat char as signed on all processors, including ARM
  IF (NOT APPLE)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIE")                     # enables support for more secure position independent execution
  ENDIF()
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")                       # generate position independent code suitable for shared libraries
  SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -fPIC")                       # generate position independent code suitable for shared libraries
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")                  # enables C++11 features    
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")         # makes all symbols hidden by default
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility-inlines-hidden") # makes all inline symbols hidden by default
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-strict-aliasing")        # disables strict aliasing rules
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-tree-vectorize")         # disable auto vectorizer
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_FORTIFY_SOURCE=2")         # perform extra security checks for some standard library calls
  IF (EMBREE_STACK_PROTECTOR)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector")           # protects against return address overrides
  ENDIF()
  MACRO(DISABLE_STACK_PROTECTOR_FOR_FILE file)
    IF (EMBREE_STACK_PROTECTOR)
      SET_SOURCE_FILES_PROPERTIES(${file} PROPERTIES COMPILE_FLAGS "-fno-stack-protector")
    ENDIF()
  ENDMACRO()

  IF (EMBREE_ADDRESS_SANITIZER)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address -fsanitize-address-use-after-scope -fno-omit-frame-pointer -fno-optimize-sibling-calls")
  ENDIF()

  IF (EMSCRIPTEN)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions")              # enable exceptions
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")                  # enable threads
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msimd128")                 # enable SIMD intrinsics
  ENDIF()

  SET(CMAKE_CXX_FLAGS_DEBUG "")
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g")              # generate debug information
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DDEBUG")         # enable assertions
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DTBB_USE_DEBUG") # configure TBB in debug mode
  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O3")             # enable full optimizations

  SET(CMAKE_CXX_FLAGS_RELEASE "")
  SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DNDEBUG")     # disable assertions
  SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")          # enable full optimizations

  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "")
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -g")              # generate debug information
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -DNDEBUG")        # disable assertions
  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -O3")             # enable full optimizations

  IF (APPLE)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mmacosx-version-min=10.7")   # makes sure code runs on older MacOSX versions
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")             # link against libc++ which supports C++11 features
  ELSE(APPLE)
    IF (NOT EMBREE_ADDRESS_SANITIZER) # for address sanitizer this causes link errors
      SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined") # issues link error for undefined symbols in shared library
      SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -pie")                     # enables position independent execution for executable
      IF (NOT EMSCRIPTEN)
        SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -z relro -z now")    # re-arranges data sections to increase security
        SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -z noexecstack")     # we do not need an executable stack
        SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -z relro -z now")          # re-arranges data sections to increase security
        SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -z noexecstack")           # we do not need an executable stack
      ENDIF()
    ENDIF()
  ENDIF(APPLE)


ENDIF()