HandleLLVMOptions.cmake [plain text]
# This CMake module is responsible for interpreting the user defined LLVM_
# options and executing the appropriate CMake commands to realize the users'
# selections.
# This is commonly needed so make sure it's defined before we include anything
# else.
string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
include(HandleLLVMStdlib)
include(AddLLVMDefinitions)
include(CheckCCompilerFlag)
include(CheckCXXCompilerFlag)
if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
message(FATAL_ERROR "Host GCC version must be at least 4.7!")
endif()
elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
message(FATAL_ERROR "Host Clang version must be at least 3.1!")
endif()
# Also test that we aren't using too old of a version of libstdc++ with the
# Clang compiler. This is tricky as there is no real way to check the
# version of libstdc++ directly. Instead we test for a known bug in
# libstdc++4.6 that is fixed in libstdc++4.7.
if(NOT LLVM_ENABLE_LIBCXX)
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
set(CMAKE_REQUIRED_FLAGS "-std=c++0x")
check_cxx_source_compiles("
#include <atomic>
std::atomic<float> x(0.0f);
int main() { return (float)x; }"
LLVM_NO_OLD_LIBSTDCXX)
if(NOT LLVM_NO_OLD_LIBSTDCXX)
message(FATAL_ERROR "Host Clang must be able to find libstdc++4.7 or newer!")
endif()
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
endif()
elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17.0)
message(FATAL_ERROR "Host Visual Studio must be at least 2012 (MSVC 17.0)")
endif()
endif()
endif()
if( LLVM_ENABLE_ASSERTIONS )
# MSVC doesn't like _DEBUG on release builds. See PR 4379.
if( NOT MSVC )
add_definitions( -D_DEBUG )
endif()
# On non-Debug builds cmake automatically defines NDEBUG, so we
# explicitly undefine it:
if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
add_definitions( -UNDEBUG )
# Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
foreach (flags_var_to_scrub
CMAKE_CXX_FLAGS_RELEASE
CMAKE_CXX_FLAGS_RELWITHDEBINFO
CMAKE_CXX_FLAGS_MINSIZEREL
CMAKE_C_FLAGS_RELEASE
CMAKE_C_FLAGS_RELWITHDEBINFO
CMAKE_C_FLAGS_MINSIZEREL)
string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
"${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
endforeach()
endif()
endif()
if(WIN32)
set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
if(CYGWIN)
set(LLVM_ON_WIN32 0)
set(LLVM_ON_UNIX 1)
else(CYGWIN)
set(LLVM_ON_WIN32 1)
set(LLVM_ON_UNIX 0)
endif(CYGWIN)
else(WIN32)
if(UNIX)
set(LLVM_ON_WIN32 0)
set(LLVM_ON_UNIX 1)
if(APPLE)
set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
else(APPLE)
set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
endif(APPLE)
else(UNIX)
MESSAGE(SEND_ERROR "Unable to determine platform")
endif(UNIX)
endif(WIN32)
set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
# We use *.dylib rather than *.so on darwin.
set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
if(APPLE)
# Darwin-specific linker flags for loadable modules.
set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
endif()
# Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
# build might work on ELF but fail on MachO/COFF.
if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR
${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD") AND
NOT LLVM_USE_SANITIZER)
set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
endif()
function(append value)
foreach(variable ${ARGN})
set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
endforeach(variable)
endfunction()
function(append_if condition value)
if (${condition})
foreach(variable ${ARGN})
set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
endforeach(variable)
endif()
endfunction()
macro(add_flag_if_supported flag name)
check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
endmacro()
function(add_flag_or_print_warning flag name)
check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
message(STATUS "Building with ${flag}")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
else()
message(WARNING "${flag} is not supported.")
endif()
endfunction()
if( LLVM_ENABLE_PIC )
if( XCODE )
# Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
# know how to disable this, so just force ENABLE_PIC off for now.
message(WARNING "-fPIC not supported with Xcode.")
elseif( WIN32 OR CYGWIN)
# On Windows all code is PIC. MinGW warns if -fPIC is used.
else()
add_flag_or_print_warning("-fPIC" FPIC)
if( WIN32 OR CYGWIN)
# MinGW warns if -fvisibility-inlines-hidden is used.
else()
check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
endif()
endif()
endif()
if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
# TODO: support other platforms and toolchains.
if( LLVM_BUILD_32_BITS )
message(STATUS "Building 32 bits executables and libraries.")
add_llvm_definitions( -m32 )
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
endif( LLVM_BUILD_32_BITS )
endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
if (LLVM_BUILD_STATIC)
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
endif()
if( XCODE )
# For Xcode enable several build settings that correspond to
# many warnings that are on by default in Clang but are
# not enabled for historical reasons. For versions of Xcode
# that do not support these options they will simply
# be ignored.
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
endif()
# On Win32 using MS tools, provide an option to set the number of parallel jobs
# to use.
if( MSVC_IDE )
set(LLVM_COMPILER_JOBS "0" CACHE STRING
"Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
if( LLVM_COMPILER_JOBS STREQUAL "0" )
add_llvm_definitions( /MP )
else()
message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
endif()
else()
message(STATUS "Parallel compilation disabled")
endif()
endif()
if( MSVC )
include(ChooseMSVCCRT)
if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
# set stack reserved size to ~10MB
# CMake previously automatically set this value for MSVC builds, but the
# behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
# value (1 MB) which is not enough for us in tasks such as parsing recursive
# C++ templates in Clang.
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
endif()
if( MSVC11 )
add_llvm_definitions(-D_VARIADIC_MAX=10)
endif()
# Add definitions that make MSVC much less annoying.
add_llvm_definitions(
# For some reason MS wants to deprecate a bunch of standard functions...
-D_CRT_SECURE_NO_DEPRECATE
-D_CRT_SECURE_NO_WARNINGS
-D_CRT_NONSTDC_NO_DEPRECATE
-D_CRT_NONSTDC_NO_WARNINGS
-D_SCL_SECURE_NO_DEPRECATE
-D_SCL_SECURE_NO_WARNINGS
# Disabled warnings.
-wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
-wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
-wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
-wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
-wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
-wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
-wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
-wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
-wd4355 # Suppress ''this' : used in base member initializer list'
-wd4456 # Suppress 'declaration of 'var' hides local variable'
-wd4457 # Suppress 'declaration of 'var' hides function parameter'
-wd4458 # Suppress 'declaration of 'var' hides class member'
-wd4459 # Suppress 'declaration of 'var' hides global declaration'
-wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
-wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
-wd4722 # Suppress 'function' : destructor never returns, potential memory leak
-wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
# Promoted warnings.
-w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
# Promoted warnings to errors.
-we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
)
# Enable warnings
if (LLVM_ENABLE_WARNINGS)
add_llvm_definitions( /W4 )
if (LLVM_ENABLE_PEDANTIC)
# No MSVC equivalent available
endif (LLVM_ENABLE_PEDANTIC)
endif (LLVM_ENABLE_WARNINGS)
if (LLVM_ENABLE_WERROR)
add_llvm_definitions( /WX )
endif (LLVM_ENABLE_WERROR)
elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
if (LLVM_ENABLE_WARNINGS)
append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
append("-Wcast-qual" CMAKE_CXX_FLAGS)
# Turn off missing field initializer warnings for gcc to avoid noise from
# false positives with empty {}. Turn them on otherwise (they're off by
# default for clang).
check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
if (CMAKE_COMPILER_IS_GNUCXX)
append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
else()
append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
endif()
append_if(LLVM_ENABLE_PEDANTIC "-pedantic -Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
# Check if -Wnon-virtual-dtor warns even though the class is marked final.
# If it does, don't add it. So it won't be added on clang 3.4 and older.
# This also catches cases when -Wnon-virtual-dtor isn't supported by
# the compiler at all.
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor")
CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();};
class derived final : public base { public: ~derived();};
int main() { return 0; }"
CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR
"-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
# Check if -Wcomment is OK with an // comment ending with '\' if the next
# line is also a // comment.
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}"
C_WCOMMENT_ALLOWS_LINE_WRAP)
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
endif (LLVM_ENABLE_WARNINGS)
append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
if (NOT LLVM_ENABLE_TIMESTAMPS)
add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
endif ()
if (LLVM_ENABLE_CXX1Y)
check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
else()
check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
if (CXX_SUPPORTS_CXX11)
if (CYGWIN OR MINGW)
# MinGW and Cygwin are a bit stricter and lack things like
# 'strdup', 'stricmp', etc in c++11 mode.
append("-std=gnu++11" CMAKE_CXX_FLAGS)
else()
append("-std=c++11" CMAKE_CXX_FLAGS)
endif()
else()
message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
endif()
endif()
if (LLVM_ENABLE_MODULES)
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fmodules -fcxx-modules")
# Check that we can build code with modules enabled, and that repeatedly
# including <cassert> still manages to respect NDEBUG properly.
CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG
#include <cassert>
#define NDEBUG
#include <cassert>
int main() { assert(this code is not compiled); }"
CXX_SUPPORTS_MODULES)
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
if (CXX_SUPPORTS_MODULES)
append_if(CXX_SUPPORTS_MODULES "-fmodules" CMAKE_C_FLAGS)
append_if(CXX_SUPPORTS_MODULES "-fmodules -fcxx-modules" CMAKE_CXX_FLAGS)
else()
message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler")
endif()
endif(LLVM_ENABLE_MODULES)
endif( MSVC )
macro(append_common_sanitizer_flags)
# Append -fno-omit-frame-pointer and turn on debug info to get better
# stack traces.
add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
endif()
# Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
add_flag_if_supported("-O1" O1)
endif()
endmacro()
# Turn on sanitizers if necessary.
if(LLVM_USE_SANITIZER)
if (LLVM_ON_UNIX)
if (LLVM_USE_SANITIZER STREQUAL "Address")
append_common_sanitizer_flags()
append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
append_common_sanitizer_flags()
append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
append_common_sanitizer_flags()
append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover"
CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
append_common_sanitizer_flags()
append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
append_common_sanitizer_flags()
append("-fsanitize=address,undefined -fno-sanitize=vptr,function -fno-sanitize-recover"
CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
else()
message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
endif()
else()
message(WARNING "LLVM_USE_SANITIZER is not supported on this platform.")
endif()
if (LLVM_USE_SANITIZE_COVERAGE)
append("-fsanitize-coverage=4" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
endif()
# Turn on -gsplit-dwarf if requested
if(LLVM_USE_SPLIT_DWARF)
add_definitions("-gsplit-dwarf")
endif()
add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
add_llvm_definitions( -D__STDC_FORMAT_MACROS )
add_llvm_definitions( -D__STDC_LIMIT_MACROS )
# clang doesn't print colored diagnostics when invoked from Ninja
if (UNIX AND
CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
CMAKE_GENERATOR STREQUAL "Ninja")
append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
# Add flags for add_dead_strip().
# FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
# But MinSizeRel seems to add that automatically, so maybe disable these
# flags instead if LLVM_NO_DEAD_STRIP is set.
if(NOT CYGWIN AND NOT WIN32)
if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
# Don't add -ffunction-section if it can be disabled with -fno-function-sections.
# Doing so will break sanitizers.
add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
endif()
add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
endif()
endif()
if(CYGWIN OR MINGW)
# Prune --out-implib from executables. It doesn't make sense even
# with --export-all-symbols.
string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
CMAKE_C_LINK_EXECUTABLE "${CMAKE_C_LINK_EXECUTABLE}")
string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_CXX_LINK_EXECUTABLE}")
endif()
if(MSVC)
# Remove flags here, for exceptions and RTTI.
# Each target property or source property should be responsible to control
# them.
# CL.EXE complains to override flags like "/GR /GR-".
string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
endif()
# Provide public options to globally control RTTI and EH
option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
endif()
# Plugin support
# FIXME: Make this configurable.
if(WIN32 OR CYGWIN)
if(BUILD_SHARED_LIBS)
set(LLVM_ENABLE_PLUGINS ON)
else()
set(LLVM_ENABLE_PLUGINS OFF)
endif()
else()
set(LLVM_ENABLE_PLUGINS ON)
endif()