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      1 # This CMake module is responsible for interpreting the user defined LLVM_
      2 # options and executing the appropriate CMake commands to realize the users'
      3 # selections.
      4 
      5 # This is commonly needed so make sure it's defined before we include anything
      6 # else.
      7 string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
      8 
      9 include(CheckCompilerVersion)
     10 include(HandleLLVMStdlib)
     11 include(CheckCCompilerFlag)
     12 include(CheckCXXCompilerFlag)
     13 
     14 if(CMAKE_LINKER MATCHES "lld-link.exe" OR (WIN32 AND LLVM_USE_LINKER STREQUAL "lld"))
     15   set(LINKER_IS_LLD_LINK TRUE)
     16 else()
     17   set(LINKER_IS_LLD_LINK FALSE)
     18 endif()
     19 
     20 set(LLVM_ENABLE_LTO OFF CACHE STRING "Build LLVM with LTO. May be specified as Thin or Full to use a particular kind of LTO")
     21 string(TOUPPER "${LLVM_ENABLE_LTO}" uppercase_LLVM_ENABLE_LTO)
     22 
     23 # Ninja Job Pool support
     24 # The following only works with the Ninja generator in CMake >= 3.0.
     25 set(LLVM_PARALLEL_COMPILE_JOBS "" CACHE STRING
     26   "Define the maximum number of concurrent compilation jobs.")
     27 if(LLVM_PARALLEL_COMPILE_JOBS)
     28   if(NOT CMAKE_MAKE_PROGRAM MATCHES "ninja")
     29     message(WARNING "Job pooling is only available with Ninja generators.")
     30   else()
     31     set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
     32     set(CMAKE_JOB_POOL_COMPILE compile_job_pool)
     33   endif()
     34 endif()
     35 
     36 set(LLVM_PARALLEL_LINK_JOBS "" CACHE STRING
     37   "Define the maximum number of concurrent link jobs.")
     38 if(CMAKE_MAKE_PROGRAM MATCHES "ninja")
     39   if(NOT LLVM_PARALLEL_LINK_JOBS AND uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
     40     message(STATUS "ThinLTO provides its own parallel linking - limiting parallel link jobs to 2.")
     41     set(LLVM_PARALLEL_LINK_JOBS "2")
     42   endif()
     43   if(LLVM_PARALLEL_LINK_JOBS)
     44     set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
     45     set(CMAKE_JOB_POOL_LINK link_job_pool)
     46   endif()
     47 elseif(LLVM_PARALLEL_LINK_JOBS)
     48   message(WARNING "Job pooling is only available with Ninja generators.")
     49 endif()
     50 
     51 if( LLVM_ENABLE_ASSERTIONS )
     52   # MSVC doesn't like _DEBUG on release builds. See PR 4379.
     53   if( NOT MSVC )
     54     add_definitions( -D_DEBUG )
     55   endif()
     56   # On non-Debug builds cmake automatically defines NDEBUG, so we
     57   # explicitly undefine it:
     58   if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
     59     add_definitions( -UNDEBUG )
     60     # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
     61     foreach (flags_var_to_scrub
     62         CMAKE_CXX_FLAGS_RELEASE
     63         CMAKE_CXX_FLAGS_RELWITHDEBINFO
     64         CMAKE_CXX_FLAGS_MINSIZEREL
     65         CMAKE_C_FLAGS_RELEASE
     66         CMAKE_C_FLAGS_RELWITHDEBINFO
     67         CMAKE_C_FLAGS_MINSIZEREL)
     68       string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
     69         "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
     70     endforeach()
     71   endif()
     72 endif()
     73 
     74 if(LLVM_ENABLE_EXPENSIVE_CHECKS)
     75   add_definitions(-DEXPENSIVE_CHECKS)
     76   add_definitions(-D_GLIBCXX_DEBUG)
     77 endif()
     78 
     79 string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
     80 
     81 if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" )
     82   if( LLVM_ENABLE_ASSERTIONS )
     83     set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
     84   endif()
     85 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" )
     86   set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
     87 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
     88   # We don't need to do anything special to turn off ABI breaking checks.
     89 elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS )
     90   # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been
     91   # defined.
     92 else()
     93   message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
     94 endif()
     95 
     96 if( LLVM_REVERSE_ITERATION )
     97   set( LLVM_ENABLE_REVERSE_ITERATION 1 )
     98 endif()
     99 
    100 if(WIN32)
    101   set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
    102   if(CYGWIN)
    103     set(LLVM_ON_WIN32 0)
    104     set(LLVM_ON_UNIX 1)
    105   else(CYGWIN)
    106     set(LLVM_ON_WIN32 1)
    107     set(LLVM_ON_UNIX 0)
    108   endif(CYGWIN)
    109 else(WIN32)
    110   if(FUCHSIA OR UNIX)
    111     set(LLVM_ON_WIN32 0)
    112     set(LLVM_ON_UNIX 1)
    113     if(APPLE OR ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
    114       set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
    115     else()
    116       set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
    117     endif()
    118   else(FUCHSIA OR UNIX)
    119     MESSAGE(SEND_ERROR "Unable to determine platform")
    120   endif(FUCHSIA OR UNIX)
    121 endif(WIN32)
    122 
    123 set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
    124 set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
    125 
    126 # We use *.dylib rather than *.so on darwin.
    127 set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
    128 
    129 if(APPLE)
    130   if(LLVM_ENABLE_LLD AND LLVM_ENABLE_LTO)
    131     message(FATAL_ERROR "lld does not support LTO on Darwin")
    132   endif()
    133   # Darwin-specific linker flags for loadable modules.
    134   set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
    135 endif()
    136 
    137 # Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
    138 # build might work on ELF but fail on MachO/COFF.
    139 if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR
    140         ${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD" OR
    141         ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD") AND
    142    NOT LLVM_USE_SANITIZER)
    143   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
    144 endif()
    145 
    146 # Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
    147 # by dlclose(). We need that since the CLI API relies on cross-references
    148 # between global objects which became horribly broken when one of the libraries
    149 # is unloaded.
    150 if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
    151   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,nodelete")
    152   set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-z,nodelete")
    153 endif()
    154 
    155 
    156 function(append value)
    157   foreach(variable ${ARGN})
    158     set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
    159   endforeach(variable)
    160 endfunction()
    161 
    162 function(append_if condition value)
    163   if (${condition})
    164     foreach(variable ${ARGN})
    165       set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
    166     endforeach(variable)
    167   endif()
    168 endfunction()
    169 
    170 macro(add_flag_if_supported flag name)
    171   check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
    172   append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
    173   check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
    174   append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
    175 endmacro()
    176 
    177 function(add_flag_or_print_warning flag name)
    178   check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
    179   check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
    180   if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
    181     message(STATUS "Building with ${flag}")
    182     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
    183     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
    184     set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE)
    185   else()
    186     message(WARNING "${flag} is not supported.")
    187   endif()
    188 endfunction()
    189 
    190 if( LLVM_ENABLE_LLD )
    191 	if ( LLVM_USE_LINKER )
    192 		message(FATAL_ERROR "LLVM_ENABLE_LLD and LLVM_USE_LINKER can't be set at the same time")
    193 	endif()
    194 	set(LLVM_USE_LINKER "lld")
    195 endif()
    196 
    197 if( LLVM_USE_LINKER )
    198   set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
    199   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fuse-ld=${LLVM_USE_LINKER}")
    200   check_cxx_source_compiles("int main() { return 0; }" CXX_SUPPORTS_CUSTOM_LINKER)
    201   if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
    202 	  message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'")
    203   endif()
    204   set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
    205   append("-fuse-ld=${LLVM_USE_LINKER}"
    206     CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    207 endif()
    208 
    209 if( LLVM_ENABLE_PIC )
    210   if( XCODE )
    211     # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
    212     # know how to disable this, so just force ENABLE_PIC off for now.
    213     message(WARNING "-fPIC not supported with Xcode.")
    214   elseif( WIN32 OR CYGWIN)
    215     # On Windows all code is PIC. MinGW warns if -fPIC is used.
    216   else()
    217     add_flag_or_print_warning("-fPIC" FPIC)
    218   endif()
    219 endif()
    220 
    221 if(NOT WIN32 AND NOT CYGWIN)
    222   # MinGW warns if -fvisibility-inlines-hidden is used.
    223   check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
    224   append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
    225 endif()
    226 
    227 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
    228   # TODO: support other platforms and toolchains.
    229   if( LLVM_BUILD_32_BITS )
    230     message(STATUS "Building 32 bits executables and libraries.")
    231     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
    232     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
    233     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
    234     set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
    235     set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
    236 
    237     # FIXME: CMAKE_SIZEOF_VOID_P is still 8
    238     add_definitions(-D_LARGEFILE_SOURCE)
    239     add_definitions(-D_FILE_OFFSET_BITS=64)
    240   endif( LLVM_BUILD_32_BITS )
    241 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
    242 
    243 # If building on a GNU specific 32-bit system, make sure off_t is 64 bits
    244 # so that off_t can stored offset > 2GB.
    245 # Android until version N (API 24) doesn't support it.
    246 if (ANDROID AND (ANDROID_NATIVE_API_LEVEL LESS 24))
    247   set(LLVM_FORCE_SMALLFILE_FOR_ANDROID TRUE)
    248 endif()
    249 if( CMAKE_SIZEOF_VOID_P EQUAL 4 AND NOT LLVM_FORCE_SMALLFILE_FOR_ANDROID)
    250   # FIXME: It isn't handled in LLVM_BUILD_32_BITS.
    251   add_definitions( -D_LARGEFILE_SOURCE )
    252   add_definitions( -D_FILE_OFFSET_BITS=64 )
    253 endif()
    254 
    255 if( XCODE )
    256   # For Xcode enable several build settings that correspond to
    257   # many warnings that are on by default in Clang but are
    258   # not enabled for historical reasons.  For versions of Xcode
    259   # that do not support these options they will simply
    260   # be ignored.
    261   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
    262   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
    263   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
    264   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
    265   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
    266   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
    267   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
    268   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
    269   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
    270   set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
    271   set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
    272   set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
    273   set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
    274   set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
    275   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
    276 endif()
    277 
    278 # On Win32 using MS tools, provide an option to set the number of parallel jobs
    279 # to use.
    280 if( MSVC_IDE )
    281   set(LLVM_COMPILER_JOBS "0" CACHE STRING
    282     "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
    283   if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
    284     if( LLVM_COMPILER_JOBS STREQUAL "0" )
    285       add_definitions( /MP )
    286     else()
    287       message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
    288       add_definitions( /MP${LLVM_COMPILER_JOBS} )
    289     endif()
    290   else()
    291     message(STATUS "Parallel compilation disabled")
    292   endif()
    293 endif()
    294 
    295 # set stack reserved size to ~10MB
    296 if(MSVC)
    297   # CMake previously automatically set this value for MSVC builds, but the
    298   # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
    299   # value (1 MB) which is not enough for us in tasks such as parsing recursive
    300   # C++ templates in Clang.
    301   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
    302 elseif(MINGW) # FIXME: Also cygwin?
    303   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
    304 
    305   # Pass -mbig-obj to mingw gas on Win64. COFF has a 2**16 section limit, and
    306   # on Win64, every COMDAT function creates at least 3 sections: .text, .pdata,
    307   # and .xdata.
    308   if (CMAKE_SIZEOF_VOID_P EQUAL 8)
    309     append("-Wa,-mbig-obj" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    310   endif()
    311 endif()
    312 
    313 if( MSVC )
    314   if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 )
    315     # For MSVC 2013, disable iterator null pointer checking in debug mode,
    316     # especially so std::equal(nullptr, nullptr, nullptr) will not assert.
    317     add_definitions("-D_DEBUG_POINTER_IMPL=")
    318   endif()
    319 
    320   include(ChooseMSVCCRT)
    321 
    322   if( MSVC11 )
    323     add_definitions(-D_VARIADIC_MAX=10)
    324   endif()
    325 
    326   # Add definitions that make MSVC much less annoying.
    327   add_definitions(
    328     # For some reason MS wants to deprecate a bunch of standard functions...
    329     -D_CRT_SECURE_NO_DEPRECATE
    330     -D_CRT_SECURE_NO_WARNINGS
    331     -D_CRT_NONSTDC_NO_DEPRECATE
    332     -D_CRT_NONSTDC_NO_WARNINGS
    333     -D_SCL_SECURE_NO_DEPRECATE
    334     -D_SCL_SECURE_NO_WARNINGS
    335     )
    336 
    337   # Tell MSVC to use the Unicode version of the Win32 APIs instead of ANSI.
    338   add_definitions(
    339     -DUNICODE
    340     -D_UNICODE
    341   )
    342 
    343   if (LLVM_ENABLE_WERROR)
    344     append("/WX" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    345   endif (LLVM_ENABLE_WERROR)
    346 
    347   append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    348 
    349   # Allow users to request PDBs in release mode. CMake offeres the
    350   # RelWithDebInfo configuration, but it uses different optimization settings
    351   # (/Ob1 vs /Ob2 or -O2 vs -O3). LLVM provides this flag so that users can get
    352   # PDBs without changing codegen.
    353   option(LLVM_ENABLE_PDB OFF)
    354   if (LLVM_ENABLE_PDB AND uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
    355     append("/Zi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    356     # /DEBUG disables linker GC and ICF, but we want those in Release mode.
    357     append("/DEBUG /OPT:REF /OPT:ICF"
    358           CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS
    359           CMAKE_SHARED_LINKER_FLAGS)
    360   endif()
    361 
    362   # /Zc:strictStrings is incompatible with VS12's (Visual Studio 2013's)
    363   # debug mode headers. Instead of only enabling them in VS2013's debug mode,
    364   # we'll just enable them for Visual Studio 2015 (VS 14, MSVC_VERSION 1900)
    365   # and up.
    366   if (NOT (MSVC_VERSION LESS 1900))
    367     # Disable string literal const->non-const type conversion.
    368     # "When specified, the compiler requires strict const-qualification
    369     # conformance for pointers initialized by using string literals."
    370     append("/Zc:strictStrings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    371   endif(NOT (MSVC_VERSION LESS 1900))
    372 
    373   # "Generate Intrinsic Functions".
    374   append("/Oi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    375 
    376   # "Enforce type conversion rules".
    377   append("/Zc:rvalueCast" CMAKE_CXX_FLAGS)
    378 
    379   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT LLVM_ENABLE_LTO)
    380     # clang-cl and cl by default produce non-deterministic binaries because
    381     # link.exe /incremental requires a timestamp in the .obj file.  clang-cl
    382     # has the flag /Brepro to force deterministic binaries. We want to pass that
    383     # whenever you're building with clang unless you're passing /incremental
    384     # or using LTO (/Brepro with LTO would result in a warning about the flag
    385     # being unused, because we're not generating object files).
    386     # This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag()
    387     # because cl.exe does not emit an error on flags it doesn't understand,
    388     # letting check_cxx_compiler_flag() claim it understands all flags.
    389     check_cxx_compiler_flag("/Brepro" SUPPORTS_BREPRO)
    390     if (SUPPORTS_BREPRO)
    391       # Check if /INCREMENTAL is passed to the linker and complain that it
    392       # won't work with /Brepro.
    393       string(TOUPPER "${CMAKE_EXE_LINKER_FLAGS}" upper_exe_flags)
    394       string(TOUPPER "${CMAKE_MODULE_LINKER_FLAGS}" upper_module_flags)
    395       string(TOUPPER "${CMAKE_SHARED_LINKER_FLAGS}" upper_shared_flags)
    396 
    397       string(FIND "${upper_exe_flags} ${upper_module_flags} ${upper_shared_flags}"
    398         "/INCREMENTAL" linker_flag_idx)
    399 
    400       if (${linker_flag_idx} GREATER -1)
    401         message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic")
    402       else()
    403         append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    404       endif()
    405     endif()
    406   endif()
    407 
    408 elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
    409   append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    410   append_if(LLVM_ENABLE_WERROR "-Wno-error" CMAKE_REQUIRED_FLAGS)
    411   add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
    412   add_flag_if_supported("-Werror=unguarded-availability-new" WERROR_UNGUARDED_AVAILABILITY_NEW)
    413   if (LLVM_ENABLE_CXX1Y)
    414     check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
    415     append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
    416   elseif(LLVM_ENABLE_CXX1Z)
    417     check_cxx_compiler_flag("-std=c++1z" CXX_SUPPORTS_CXX1Z)
    418     append_if(CXX_SUPPORTS_CXX1Z "-std=c++1z" CMAKE_CXX_FLAGS)
    419   else()
    420     check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
    421     if (CXX_SUPPORTS_CXX11)
    422       if (CYGWIN OR MINGW)
    423         # MinGW and Cygwin are a bit stricter and lack things like
    424         # 'strdup', 'stricmp', etc in c++11 mode.
    425         append("-std=gnu++11" CMAKE_CXX_FLAGS)
    426       else()
    427         append("-std=c++11" CMAKE_CXX_FLAGS)
    428       endif()
    429     else()
    430       message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
    431     endif()
    432   endif()
    433   if (LLVM_ENABLE_MODULES)
    434     set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
    435     set(module_flags "-fmodules -fmodules-cache-path=${PROJECT_BINARY_DIR}/module.cache")
    436     if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
    437       # On Darwin -fmodules does not imply -fcxx-modules.
    438       set(module_flags "${module_flags} -fcxx-modules")
    439     endif()
    440     if (LLVM_ENABLE_LOCAL_SUBMODULE_VISIBILITY)
    441       set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility")
    442     endif()
    443     if (LLVM_ENABLE_MODULE_DEBUGGING AND
    444         ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
    445          (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
    446       set(module_flags "${module_flags} -gmodules")
    447     endif()
    448     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${module_flags}")
    449 
    450     # Check that we can build code with modules enabled, and that repeatedly
    451     # including <cassert> still manages to respect NDEBUG properly.
    452     CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG
    453                                #include <cassert>
    454                                #define NDEBUG
    455                                #include <cassert>
    456                                int main() { assert(this code is not compiled); }"
    457                                CXX_SUPPORTS_MODULES)
    458     set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
    459     if (CXX_SUPPORTS_MODULES)
    460       append("${module_flags}" CMAKE_CXX_FLAGS)
    461     else()
    462       message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler")
    463     endif()
    464   endif(LLVM_ENABLE_MODULES)
    465 endif( MSVC )
    466 
    467 if (MSVC)
    468   if (NOT CLANG_CL)
    469     set(msvc_warning_flags
    470       # Disabled warnings.
    471       -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline)
    472       -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
    473       -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
    474       -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
    475       -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
    476       -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
    477       -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
    478       -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
    479       -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
    480       -wd4355 # Suppress ''this' : used in base member initializer list'
    481       -wd4456 # Suppress 'declaration of 'var' hides local variable'
    482       -wd4457 # Suppress 'declaration of 'var' hides function parameter'
    483       -wd4458 # Suppress 'declaration of 'var' hides class member'
    484       -wd4459 # Suppress 'declaration of 'var' hides global declaration'
    485       -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
    486       -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
    487       -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
    488       -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
    489       -wd4100 # Suppress 'unreferenced formal parameter'
    490       -wd4127 # Suppress 'conditional expression is constant'
    491       -wd4512 # Suppress 'assignment operator could not be generated'
    492       -wd4505 # Suppress 'unreferenced local function has been removed'
    493       -wd4610 # Suppress '<class> can never be instantiated'
    494       -wd4510 # Suppress 'default constructor could not be generated'
    495       -wd4702 # Suppress 'unreachable code'
    496       -wd4245 # Suppress 'signed/unsigned mismatch'
    497       -wd4706 # Suppress 'assignment within conditional expression'
    498       -wd4310 # Suppress 'cast truncates constant value'
    499       -wd4701 # Suppress 'potentially uninitialized local variable'
    500       -wd4703 # Suppress 'potentially uninitialized local pointer variable'
    501       -wd4389 # Suppress 'signed/unsigned mismatch'
    502       -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable'
    503       -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation'
    504       -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer'
    505       -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed'
    506       -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared'
    507           # C4592 is disabled because of false positives in Visual Studio 2015
    508           # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2.
    509       -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation)
    510       -wd4319 # Suppress ''operator' : zero extending 'type' to 'type' of greater size'
    511 
    512       # Ideally, we'd like this warning to be enabled, but MSVC 2013 doesn't
    513       # support the 'aligned' attribute in the way that clang sources requires (for
    514       # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to
    515       # avoid unwanted alignment warnings.
    516       # When we switch to requiring a version of MSVC that supports the 'alignas'
    517       # specifier (MSVC 2015?) this warning can be re-enabled.
    518       -wd4324 # Suppress 'structure was padded due to __declspec(align())'
    519 
    520       # Promoted warnings.
    521       -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
    522 
    523       # Promoted warnings to errors.
    524       -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
    525       )
    526   endif(NOT CLANG_CL)
    527 
    528   # Enable warnings
    529   if (LLVM_ENABLE_WARNINGS)
    530     # Put /W4 in front of all the -we flags. cl.exe doesn't care, but for
    531     # clang-cl having /W4 after the -we flags will re-enable the warnings
    532     # disabled by -we.
    533     set(msvc_warning_flags "/W4 ${msvc_warning_flags}")
    534     # CMake appends /W3 by default, and having /W3 followed by /W4 will result in
    535     # cl : Command line warning D9025 : overriding '/W3' with '/W4'.  Since this is
    536     # a command line warning and not a compiler warning, it cannot be suppressed except
    537     # by fixing the command line.
    538     string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
    539     string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
    540 
    541     if (LLVM_ENABLE_PEDANTIC)
    542       # No MSVC equivalent available
    543     endif (LLVM_ENABLE_PEDANTIC)
    544   endif (LLVM_ENABLE_WARNINGS)
    545 
    546   foreach(flag ${msvc_warning_flags})
    547     append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    548   endforeach(flag)
    549 endif (MSVC)
    550 
    551 if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
    552 
    553   # Don't add -Wall for clang-cl, because it maps -Wall to -Weverything for
    554   # MSVC compatibility.  /W4 is added above instead.
    555   if (NOT CLANG_CL)
    556     append("-Wall" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    557   endif()
    558 
    559   append("-Wextra -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    560   append("-Wcast-qual" CMAKE_CXX_FLAGS)
    561 
    562   # Turn off missing field initializer warnings for gcc to avoid noise from
    563   # false positives with empty {}. Turn them on otherwise (they're off by
    564   # default for clang).
    565   check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
    566   if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
    567     if (CMAKE_COMPILER_IS_GNUCXX)
    568       append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    569     else()
    570       append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    571     endif()
    572   endif()
    573 
    574   if (LLVM_ENABLE_PEDANTIC AND LLVM_COMPILER_IS_GCC_COMPATIBLE)
    575     append("-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    576     append("-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    577   endif()
    578 
    579   add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
    580   append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
    581   append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
    582 
    583   # Disable -Wclass-memaccess, a C++-only warning from GCC 8 that fires on
    584   # LLVM's ADT classes.
    585   check_cxx_compiler_flag("-Wclass-memaccess" CXX_SUPPORTS_CLASS_MEMACCESS_FLAG)
    586   append_if(CXX_SUPPORTS_CLASS_MEMACCESS_FLAG "-Wno-class-memaccess" CMAKE_CXX_FLAGS)
    587 
    588   # Check if -Wnon-virtual-dtor warns even though the class is marked final.
    589   # If it does, don't add it. So it won't be added on clang 3.4 and older.
    590   # This also catches cases when -Wnon-virtual-dtor isn't supported by
    591   # the compiler at all.  This flag is not activated for gcc since it will
    592   # incorrectly identify a protected non-virtual base when there is a friend
    593   # declaration. Don't activate this in general on Windows as this warning has
    594   # too many false positives on COM-style classes, which are destroyed with
    595   # Release() (PR32286).
    596   if (NOT CMAKE_COMPILER_IS_GNUCXX AND NOT WIN32)
    597     set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
    598     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor")
    599     CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();};
    600                                class derived final : public base { public: ~derived();};
    601                                int main() { return 0; }"
    602                               CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
    603     set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
    604     append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR
    605               "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
    606   endif()
    607 
    608   # Enable -Wdelete-non-virtual-dtor if available.
    609   add_flag_if_supported("-Wdelete-non-virtual-dtor" DELETE_NON_VIRTUAL_DTOR_FLAG)
    610 
    611   # Check if -Wcomment is OK with an // comment ending with '\' if the next
    612   # line is also a // comment.
    613   set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
    614   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
    615   CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}"
    616                           C_WCOMMENT_ALLOWS_LINE_WRAP)
    617   set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
    618   if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
    619     append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    620   endif()
    621 
    622   # Enable -Wstring-conversion to catch misuse of string literals.
    623   add_flag_if_supported("-Wstring-conversion" STRING_CONVERSION_FLAG)
    624 endif (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
    625 
    626 if (LLVM_COMPILER_IS_GCC_COMPATIBLE AND NOT LLVM_ENABLE_WARNINGS)
    627   append("-w" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    628 endif()
    629 
    630 macro(append_common_sanitizer_flags)
    631   if (NOT MSVC)
    632     # Append -fno-omit-frame-pointer and turn on debug info to get better
    633     # stack traces.
    634     add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
    635     if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
    636         NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
    637       add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
    638     endif()
    639     # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
    640     if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND LLVM_OPTIMIZE_SANITIZED_BUILDS)
    641       add_flag_if_supported("-O1" O1)
    642     endif()
    643   elseif (CLANG_CL)
    644     # Keep frame pointers around.
    645     append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    646     if (LINKER_IS_LLD_LINK)
    647       # Use DWARF debug info with LLD.
    648       append("-gdwarf" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    649     else()
    650       # Enable codeview otherwise.
    651       append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    652     endif()
    653     # Always ask the linker to produce symbols with asan.
    654     append("-debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    655   endif()
    656 endmacro()
    657 
    658 # Turn on sanitizers if necessary.
    659 if(LLVM_USE_SANITIZER)
    660   if (LLVM_ON_UNIX)
    661     if (LLVM_USE_SANITIZER STREQUAL "Address")
    662       append_common_sanitizer_flags()
    663       append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    664     elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
    665       append_common_sanitizer_flags()
    666       append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    667       if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
    668         append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    669       endif()
    670     elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
    671       append_common_sanitizer_flags()
    672       append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
    673               CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    674     elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
    675       append_common_sanitizer_flags()
    676       append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    677     elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
    678             LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
    679       append_common_sanitizer_flags()
    680       append("-fsanitize=address,undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
    681               CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    682     elseif (LLVM_USE_SANITIZER STREQUAL "Leaks")
    683       append_common_sanitizer_flags()
    684       append("-fsanitize=leak" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    685     else()
    686       message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
    687     endif()
    688   elseif(MSVC)
    689     if (LLVM_USE_SANITIZER STREQUAL "Address")
    690       append_common_sanitizer_flags()
    691       append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    692     else()
    693       message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}")
    694     endif()
    695   else()
    696     message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.")
    697   endif()
    698   if (LLVM_USE_SANITIZER MATCHES "(Undefined;)?Address(;Undefined)?")
    699     add_flag_if_supported("-fsanitize-address-use-after-scope"
    700                           FSANITIZE_USE_AFTER_SCOPE_FLAG)
    701   endif()
    702   if (LLVM_USE_SANITIZE_COVERAGE)
    703     append("-fsanitize=fuzzer-no-link" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    704   endif()
    705   if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
    706     set(BLACKLIST_FILE "${CMAKE_SOURCE_DIR}/utils/sanitizers/ubsan_blacklist.txt")
    707     if (EXISTS "${BLACKLIST_FILE}")
    708       append("-fsanitize-blacklist=${BLACKLIST_FILE}"
    709              CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    710     endif()
    711   endif()
    712 endif()
    713 
    714 # Turn on -gsplit-dwarf if requested
    715 if(LLVM_USE_SPLIT_DWARF)
    716   add_definitions("-gsplit-dwarf")
    717 endif()
    718 
    719 add_definitions( -D__STDC_CONSTANT_MACROS )
    720 add_definitions( -D__STDC_FORMAT_MACROS )
    721 add_definitions( -D__STDC_LIMIT_MACROS )
    722 
    723 # clang and gcc don't default-print colored diagnostics when invoked from Ninja.
    724 if (UNIX AND
    725     CMAKE_GENERATOR STREQUAL "Ninja" AND
    726     (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
    727      (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND
    728       NOT (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9))))
    729   append("-fdiagnostics-color" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    730 endif()
    731 
    732 # lld doesn't print colored diagnostics when invoked from Ninja
    733 if (UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")
    734   include(CheckLinkerFlag)
    735   check_linker_flag("-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
    736   append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,--color-diagnostics"
    737     CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    738 endif()
    739 
    740 # Add flags for add_dead_strip().
    741 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
    742 # But MinSizeRel seems to add that automatically, so maybe disable these
    743 # flags instead if LLVM_NO_DEAD_STRIP is set.
    744 if(NOT CYGWIN AND NOT WIN32)
    745   if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
    746      NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
    747     check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
    748     if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
    749       # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
    750       # Doing so will break sanitizers.
    751       add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
    752     endif()
    753     add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
    754   endif()
    755 endif()
    756 
    757 if(MSVC)
    758   # Remove flags here, for exceptions and RTTI.
    759   # Each target property or source property should be responsible to control
    760   # them.
    761   # CL.EXE complains to override flags like "/GR /GR-".
    762   string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
    763   string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
    764 endif()
    765 
    766 # Provide public options to globally control RTTI and EH
    767 option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
    768 option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
    769 if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
    770   message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
    771 endif()
    772 
    773 option(LLVM_ENABLE_IR_PGO "Build LLVM and tools with IR PGO instrumentation (deprecated)" Off)
    774 mark_as_advanced(LLVM_ENABLE_IR_PGO)
    775 
    776 set(LLVM_BUILD_INSTRUMENTED OFF CACHE STRING "Build LLVM and tools with PGO instrumentation. May be specified as IR or Frontend")
    777 mark_as_advanced(LLVM_BUILD_INSTRUMENTED)
    778 string(TOUPPER "${LLVM_BUILD_INSTRUMENTED}" uppercase_LLVM_BUILD_INSTRUMENTED)
    779 
    780 if (LLVM_BUILD_INSTRUMENTED)
    781   if (LLVM_ENABLE_IR_PGO OR uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "IR")
    782     append("-fprofile-generate='${LLVM_PROFILE_DATA_DIR}'"
    783       CMAKE_CXX_FLAGS
    784       CMAKE_C_FLAGS
    785       CMAKE_EXE_LINKER_FLAGS
    786       CMAKE_SHARED_LINKER_FLAGS)
    787   else()
    788     append("-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}'"
    789       CMAKE_CXX_FLAGS
    790       CMAKE_C_FLAGS
    791       CMAKE_EXE_LINKER_FLAGS
    792       CMAKE_SHARED_LINKER_FLAGS)
    793   endif()
    794 endif()
    795 
    796 option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation" Off)
    797 mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE)
    798 append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}' -fcoverage-mapping"
    799   CMAKE_CXX_FLAGS
    800   CMAKE_C_FLAGS
    801   CMAKE_EXE_LINKER_FLAGS
    802   CMAKE_SHARED_LINKER_FLAGS)
    803 
    804 if (LLVM_BUILD_INSTRUMENTED AND LLVM_BUILD_INSTRUMENTED_COVERAGE)
    805   message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
    806 endif()
    807 
    808 if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK)
    809   message(FATAL_ERROR "When compiling for Windows, LLVM_ENABLE_LTO requires using lld as the linker (point CMAKE_LINKER at lld-link.exe)")
    810 endif()
    811 if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
    812   append("-flto=thin" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
    813   if(NOT LINKER_IS_LLD_LINK)
    814     append("-flto=thin" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    815   endif()
    816   # If the linker supports it, enable the lto cache. This improves initial build
    817   # time a little since we re-link a lot of the same objects, and significantly
    818   # improves incremental build time.
    819   # FIXME: We should move all this logic into the clang driver.
    820   if(APPLE)
    821     append("-Wl,-cache_path_lto,${PROJECT_BINARY_DIR}/lto.cache"
    822            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    823   elseif(UNIX AND LLVM_USE_LINKER STREQUAL "lld")
    824     append("-Wl,--thinlto-cache-dir=${PROJECT_BINARY_DIR}/lto.cache"
    825            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    826   elseif(LLVM_USE_LINKER STREQUAL "gold")
    827     append("-Wl,--plugin-opt,cache-dir=${PROJECT_BINARY_DIR}/lto.cache"
    828            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    829   endif()
    830 elseif(uppercase_LLVM_ENABLE_LTO STREQUAL "FULL")
    831   append("-flto=full" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
    832   if(NOT LINKER_IS_LLD_LINK)
    833     append("-flto=full" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    834   endif()
    835 elseif(LLVM_ENABLE_LTO)
    836   append("-flto" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
    837   if(NOT LINKER_IS_LLD_LINK)
    838     append("-flto" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
    839   endif()
    840 endif()
    841 
    842 # This option makes utils/extract_symbols.py be used to determine the list of
    843 # symbols to export from LLVM tools. This is necessary when using MSVC if you
    844 # want to allow plugins, though note that the plugin has to explicitly link
    845 # against (exactly one) tool so we can't unilaterally turn on
    846 # LLVM_ENABLE_PLUGINS when it's enabled.
    847 option(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS "Export symbols from LLVM tools so that plugins can import them" OFF)
    848 if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
    849   message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
    850 endif()
    851 if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
    852   message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
    853 endif()
    854 
    855 # Plugin support
    856 # FIXME: Make this configurable.
    857 if(WIN32 OR CYGWIN)
    858   if(BUILD_SHARED_LIBS OR LLVM_BUILD_LLVM_DYLIB)
    859     set(LLVM_ENABLE_PLUGINS ON)
    860   else()
    861     set(LLVM_ENABLE_PLUGINS OFF)
    862   endif()
    863 else()
    864   set(LLVM_ENABLE_PLUGINS ON)
    865 endif()
    866 
    867 set(LLVM_ENABLE_IDE_default OFF)
    868 if (XCODE OR MSVC_IDE OR CMAKE_EXTRA_GENERATOR)
    869   set(LLVM_ENABLE_IDE_default ON)
    870 endif()
    871 option(LLVM_ENABLE_IDE "Generate targets and process sources for use with an IDE"
    872     ${LLVM_ENABLE_IDE_default})
    873 
    874 function(get_compile_definitions)
    875   get_directory_property(top_dir_definitions DIRECTORY ${CMAKE_SOURCE_DIR} COMPILE_DEFINITIONS)
    876   foreach(definition ${top_dir_definitions})
    877     if(DEFINED result)
    878       string(APPEND result " -D${definition}")
    879     else()
    880       set(result "-D${definition}")
    881     endif()
    882   endforeach()
    883   set(LLVM_DEFINITIONS "${result}" PARENT_SCOPE)
    884 endfunction()
    885 get_compile_definitions()
    886 
    887 option(LLVM_FORCE_ENABLE_STATS "Enable statistics collection for builds that wouldn't normally enable it" OFF)
    888