1 # This CMake module is responsible for interpreting the user defined LLVM_
2 # options and executing the appropriate CMake commands to realize the users'
5 # This is commonly needed so make sure it's defined before we include anything
7 string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
9 include(CheckCompilerVersion)
10 include(HandleLLVMStdlib)
11 include(AddLLVMDefinitions)
12 include(CheckCCompilerFlag)
13 include(CheckCXXCompilerFlag)
15 # Ninja Job Pool support
16 # The following only works with the Ninja generator in CMake >= 3.0.
17 set(LLVM_PARALLEL_COMPILE_JOBS "" CACHE STRING
18 "Define the maximum number of concurrent compilation jobs.")
19 if(LLVM_PARALLEL_COMPILE_JOBS)
20 if(NOT CMAKE_MAKE_PROGRAM MATCHES "ninja")
21 message(WARNING "Job pooling is only available with Ninja generators.")
23 set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
24 set(CMAKE_JOB_POOL_COMPILE compile_job_pool)
28 set(LLVM_PARALLEL_LINK_JOBS "" CACHE STRING
29 "Define the maximum number of concurrent link jobs.")
30 if(LLVM_PARALLEL_LINK_JOBS)
31 if(NOT CMAKE_MAKE_PROGRAM MATCHES "ninja")
32 message(WARNING "Job pooling is only available with Ninja generators.")
34 set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
35 set(CMAKE_JOB_POOL_LINK link_job_pool)
40 if (CMAKE_LINKER MATCHES "lld-link.exe")
41 # Pass /MANIFEST:NO so that CMake doesn't run mt.exe on our binaries. Adding
42 # manifests with mt.exe breaks LLD's symbol tables and takes as much time as
43 # the link. See PR24476.
45 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
48 if( LLVM_ENABLE_ASSERTIONS )
49 # MSVC doesn't like _DEBUG on release builds. See PR 4379.
51 add_definitions( -D_DEBUG )
53 # On non-Debug builds cmake automatically defines NDEBUG, so we
54 # explicitly undefine it:
55 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
56 add_definitions( -UNDEBUG )
57 # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
58 foreach (flags_var_to_scrub
59 CMAKE_CXX_FLAGS_RELEASE
60 CMAKE_CXX_FLAGS_RELWITHDEBINFO
61 CMAKE_CXX_FLAGS_MINSIZEREL
63 CMAKE_C_FLAGS_RELWITHDEBINFO
64 CMAKE_C_FLAGS_MINSIZEREL)
65 string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
66 "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
71 if(LLVM_ENABLE_EXPENSIVE_CHECKS)
72 add_definitions(-DEXPENSIVE_CHECKS)
73 add_definitions(-D_GLIBCXX_DEBUG)
76 string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
78 if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" )
79 if( LLVM_ENABLE_ASSERTIONS )
80 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
82 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" )
83 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
84 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
85 # We don't need to do anything special to turn off ABI breaking checks.
86 elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS )
87 # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been
90 message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
94 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
106 if(APPLE OR ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
107 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
109 set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
112 MESSAGE(SEND_ERROR "Unable to determine platform")
116 set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
117 set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
119 # We use *.dylib rather than *.so on darwin.
120 set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
123 if(LLVM_ENABLE_LLD AND LLVM_ENABLE_LTO)
124 message(FATAL_ERROR "lld does not support LTO on Darwin")
126 # Darwin-specific linker flags for loadable modules.
127 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
130 # Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
131 # build might work on ELF but fail on MachO/COFF.
132 if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR
133 ${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD" OR
134 ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD") AND
135 NOT LLVM_USE_SANITIZER)
136 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
140 function(append value)
141 foreach(variable ${ARGN})
142 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
146 function(append_if condition value)
148 foreach(variable ${ARGN})
149 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
154 macro(add_flag_if_supported flag name)
155 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
156 append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
157 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
158 append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
161 function(add_flag_or_print_warning flag name)
162 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
163 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
164 if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
165 message(STATUS "Building with ${flag}")
166 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
167 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
168 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE)
170 message(WARNING "${flag} is not supported.")
174 if( LLVM_ENABLE_LLD )
175 if ( LLVM_USE_LINKER )
176 message(FATAL_ERROR "LLVM_ENABLE_LLD and LLVM_USE_LINKER can't be set at the same time")
178 set(LLVM_USE_LINKER "lld")
181 if( LLVM_USE_LINKER )
182 check_cxx_compiler_flag("-fuse-ld=${LLVM_USE_LINKER}" CXX_SUPPORTS_CUSTOM_LINKER)
183 if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
184 message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'")
186 append("-fuse-ld=${LLVM_USE_LINKER}"
187 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
190 if( LLVM_ENABLE_PIC )
192 # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
193 # know how to disable this, so just force ENABLE_PIC off for now.
194 message(WARNING "-fPIC not supported with Xcode.")
195 elseif( WIN32 OR CYGWIN)
196 # On Windows all code is PIC. MinGW warns if -fPIC is used.
198 add_flag_or_print_warning("-fPIC" FPIC)
202 if(NOT WIN32 AND NOT CYGWIN)
203 # MinGW warns if -fvisibility-inlines-hidden is used.
204 check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
205 append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
208 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
209 # TODO: support other platforms and toolchains.
210 if( LLVM_BUILD_32_BITS )
211 message(STATUS "Building 32 bits executables and libraries.")
212 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
213 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
214 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
215 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
216 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
217 endif( LLVM_BUILD_32_BITS )
218 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
221 # For Xcode enable several build settings that correspond to
222 # many warnings that are on by default in Clang but are
223 # not enabled for historical reasons. For versions of Xcode
224 # that do not support these options they will simply
226 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
227 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
228 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
229 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
230 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
231 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
232 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
233 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
234 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
235 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
236 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
237 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
238 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
239 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
240 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
243 # On Win32 using MS tools, provide an option to set the number of parallel jobs
246 set(LLVM_COMPILER_JOBS "0" CACHE STRING
247 "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
248 if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
249 if( LLVM_COMPILER_JOBS STREQUAL "0" )
250 add_llvm_definitions( /MP )
252 message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
253 add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
256 message(STATUS "Parallel compilation disabled")
260 # set stack reserved size to ~10MB
262 # CMake previously automatically set this value for MSVC builds, but the
263 # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
264 # value (1 MB) which is not enough for us in tasks such as parsing recursive
265 # C++ templates in Clang.
266 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
267 elseif(MINGW) # FIXME: Also cygwin?
268 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
270 # Pass -mbig-obj to mingw gas on Win64. COFF has a 2**16 section limit, and
271 # on Win64, every COMDAT function creates at least 3 sections: .text, .pdata,
273 if (CMAKE_SIZEOF_VOID_P EQUAL 8)
274 append("-Wa,-mbig-obj" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
279 if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 )
280 # For MSVC 2013, disable iterator null pointer checking in debug mode,
281 # especially so std::equal(nullptr, nullptr, nullptr) will not assert.
282 add_llvm_definitions("-D_DEBUG_POINTER_IMPL=")
285 include(ChooseMSVCCRT)
288 add_llvm_definitions(-D_VARIADIC_MAX=10)
291 # Add definitions that make MSVC much less annoying.
292 add_llvm_definitions(
293 # For some reason MS wants to deprecate a bunch of standard functions...
294 -D_CRT_SECURE_NO_DEPRECATE
295 -D_CRT_SECURE_NO_WARNINGS
296 -D_CRT_NONSTDC_NO_DEPRECATE
297 -D_CRT_NONSTDC_NO_WARNINGS
298 -D_SCL_SECURE_NO_DEPRECATE
299 -D_SCL_SECURE_NO_WARNINGS
302 # Tell MSVC to use the Unicode version of the Win32 APIs instead of ANSI.
303 add_llvm_definitions(
308 set(msvc_warning_flags
310 -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline)
311 -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
312 -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
313 -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
314 -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
315 -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
316 -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
317 -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
318 -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
319 -wd4355 # Suppress ''this' : used in base member initializer list'
320 -wd4456 # Suppress 'declaration of 'var' hides local variable'
321 -wd4457 # Suppress 'declaration of 'var' hides function parameter'
322 -wd4458 # Suppress 'declaration of 'var' hides class member'
323 -wd4459 # Suppress 'declaration of 'var' hides global declaration'
324 -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
325 -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
326 -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
327 -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
328 -wd4100 # Suppress 'unreferenced formal parameter'
329 -wd4127 # Suppress 'conditional expression is constant'
330 -wd4512 # Suppress 'assignment operator could not be generated'
331 -wd4505 # Suppress 'unreferenced local function has been removed'
332 -wd4610 # Suppress '<class> can never be instantiated'
333 -wd4510 # Suppress 'default constructor could not be generated'
334 -wd4702 # Suppress 'unreachable code'
335 -wd4245 # Suppress 'signed/unsigned mismatch'
336 -wd4706 # Suppress 'assignment within conditional expression'
337 -wd4310 # Suppress 'cast truncates constant value'
338 -wd4701 # Suppress 'potentially uninitialized local variable'
339 -wd4703 # Suppress 'potentially uninitialized local pointer variable'
340 -wd4389 # Suppress 'signed/unsigned mismatch'
341 -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable'
342 -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation'
343 -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer'
344 -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed'
345 -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared'
346 # C4592 is disabled because of false positives in Visual Studio 2015
347 # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2.
348 -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation)
349 -wd4319 # Suppress ''operator' : zero extending 'type' to 'type' of greater size'
351 # Ideally, we'd like this warning to be enabled, but MSVC 2013 doesn't
352 # support the 'aligned' attribute in the way that clang sources requires (for
353 # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to
354 # avoid unwanted alignment warnings.
355 # When we switch to requiring a version of MSVC that supports the 'alignas'
356 # specifier (MSVC 2015?) this warning can be re-enabled.
357 -wd4324 # Suppress 'structure was padded due to __declspec(align())'
360 -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
362 # Promoted warnings to errors.
363 -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
367 if (LLVM_ENABLE_WARNINGS)
368 # Put /W4 in front of all the -we flags. cl.exe doesn't care, but for
369 # clang-cl having /W4 after the -we flags will re-enable the warnings
371 set(msvc_warning_flags "/W4 ${msvc_warning_flags}")
372 # CMake appends /W3 by default, and having /W3 followed by /W4 will result in
373 # cl : Command line warning D9025 : overriding '/W3' with '/W4'. Since this is
374 # a command line warning and not a compiler warning, it cannot be suppressed except
375 # by fixing the command line.
376 string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
377 string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
379 if (LLVM_ENABLE_PEDANTIC)
380 # No MSVC equivalent available
381 endif (LLVM_ENABLE_PEDANTIC)
382 endif (LLVM_ENABLE_WARNINGS)
383 if (LLVM_ENABLE_WERROR)
384 append("/WX" msvc_warning_flags)
385 endif (LLVM_ENABLE_WERROR)
387 foreach(flag ${msvc_warning_flags})
388 append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
391 append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
393 # /Zc:strictStrings is incompatible with VS12's (Visual Studio 2013's)
394 # debug mode headers. Instead of only enabling them in VS2013's debug mode,
395 # we'll just enable them for Visual Studio 2015 (VS 14, MSVC_VERSION 1900)
397 if (NOT (MSVC_VERSION LESS 1900))
398 # Disable string literal const->non-const type conversion.
399 # "When specified, the compiler requires strict const-qualification
400 # conformance for pointers initialized by using string literals."
401 append("/Zc:strictStrings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
402 endif(NOT (MSVC_VERSION LESS 1900))
404 # "Generate Intrinsic Functions".
405 append("/Oi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
407 # "Enforce type conversion rules".
408 append("/Zc:rvalueCast" CMAKE_CXX_FLAGS)
410 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
411 # clang-cl and cl by default produce non-deterministic binaries because
412 # link.exe /incremental requires a timestamp in the .obj file. clang-cl
413 # has the flag /Brepro to force deterministic binaries. We want to pass that
414 # whenever you're building with clang unless you're passing /incremental.
415 # This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag()
416 # because cl.exe does not emit an error on flags it doesn't understand,
417 # letting check_cxx_compiler_flag() claim it understands all flags.
418 check_cxx_compiler_flag("/Brepro" SUPPORTS_BREPRO)
420 # Check if /INCREMENTAL is passed to the linker and complain that it
421 # won't work with /Brepro.
422 string(TOUPPER "${CMAKE_EXE_LINKER_FLAGS}" upper_exe_flags)
423 string(TOUPPER "${CMAKE_MODULE_LINKER_FLAGS}" upper_module_flags)
424 string(TOUPPER "${CMAKE_SHARED_LINKER_FLAGS}" upper_shared_flags)
426 string(FIND "${upper_exe_flags} ${upper_module_flags} ${upper_shared_flags}"
427 "/INCREMENTAL" linker_flag_idx)
429 if (${linker_flag_idx} GREATER -1)
430 message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic")
432 append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
437 elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
438 if (LLVM_ENABLE_WARNINGS)
439 append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
440 append("-Wcast-qual" CMAKE_CXX_FLAGS)
442 # Turn off missing field initializer warnings for gcc to avoid noise from
443 # false positives with empty {}. Turn them on otherwise (they're off by
444 # default for clang).
445 check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
446 if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
447 if (CMAKE_COMPILER_IS_GNUCXX)
448 append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
450 append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
454 append_if(LLVM_ENABLE_PEDANTIC "-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
455 append_if(LLVM_ENABLE_PEDANTIC "-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
456 add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
457 append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
458 append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
460 # Check if -Wnon-virtual-dtor warns even though the class is marked final.
461 # If it does, don't add it. So it won't be added on clang 3.4 and older.
462 # This also catches cases when -Wnon-virtual-dtor isn't supported by
463 # the compiler at all. This flag is not activated for gcc since it will
464 # incorrectly identify a protected non-virtual base when there is a friend
466 if (NOT CMAKE_COMPILER_IS_GNUCXX)
467 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
468 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor")
469 CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();};
470 class derived final : public base { public: ~derived();};
471 int main() { return 0; }"
472 CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
473 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
474 append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR
475 "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
478 # Enable -Wdelete-non-virtual-dtor if available.
479 add_flag_if_supported("-Wdelete-non-virtual-dtor" DELETE_NON_VIRTUAL_DTOR_FLAG)
481 # Check if -Wcomment is OK with an // comment ending with '\' if the next
482 # line is also a // comment.
483 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
484 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
485 CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}"
486 C_WCOMMENT_ALLOWS_LINE_WRAP)
487 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
488 if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
489 append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
492 # Enable -Wstring-conversion to catch misuse of string literals.
493 add_flag_if_supported("-Wstring-conversion" STRING_CONVERSION_FLAG)
494 endif (LLVM_ENABLE_WARNINGS)
495 append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
496 add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
497 if (LLVM_ENABLE_CXX1Y)
498 check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
499 append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
501 check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
502 if (CXX_SUPPORTS_CXX11)
504 # MinGW and Cygwin are a bit stricter and lack things like
505 # 'strdup', 'stricmp', etc in c++11 mode.
506 append("-std=gnu++11" CMAKE_CXX_FLAGS)
508 append("-std=c++11" CMAKE_CXX_FLAGS)
511 message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
514 if (LLVM_ENABLE_MODULES)
515 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
516 set(module_flags "-fmodules -fmodules-cache-path=${PROJECT_BINARY_DIR}/module.cache")
517 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
518 # On Darwin -fmodules does not imply -fcxx-modules.
519 set(module_flags "${module_flags} -fcxx-modules")
521 if (LLVM_ENABLE_LOCAL_SUBMODULE_VISIBILITY)
522 set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility")
524 if (LLVM_ENABLE_MODULE_DEBUGGING AND
525 ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
526 (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
527 set(module_flags "${module_flags} -gmodules")
529 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${module_flags}")
531 # Check that we can build code with modules enabled, and that repeatedly
532 # including <cassert> still manages to respect NDEBUG properly.
533 CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG
537 int main() { assert(this code is not compiled); }"
538 CXX_SUPPORTS_MODULES)
539 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
540 if (CXX_SUPPORTS_MODULES)
541 append("${module_flags}" CMAKE_CXX_FLAGS)
543 message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler")
545 endif(LLVM_ENABLE_MODULES)
548 macro(append_common_sanitizer_flags)
550 # Append -fno-omit-frame-pointer and turn on debug info to get better
552 add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
553 if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
554 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
555 add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
557 # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
558 if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
559 add_flag_if_supported("-O1" O1)
562 # Keep frame pointers around.
563 append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
564 if (CMAKE_LINKER MATCHES "lld-link.exe")
565 # Use DWARF debug info with LLD.
566 append("-gdwarf" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
568 # Enable codeview otherwise.
569 append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
571 # Always ask the linker to produce symbols with asan.
572 append("-debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
576 # Turn on sanitizers if necessary.
577 if(LLVM_USE_SANITIZER)
579 if (LLVM_USE_SANITIZER STREQUAL "Address")
580 append_common_sanitizer_flags()
581 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
582 elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
583 append_common_sanitizer_flags()
584 append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
585 if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
586 append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
588 elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
589 append_common_sanitizer_flags()
590 append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
591 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
592 append("-fsanitize-blacklist=${CMAKE_SOURCE_DIR}/utils/sanitizers/ubsan_blacklist.txt"
593 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
594 elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
595 append_common_sanitizer_flags()
596 append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
597 elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
598 LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
599 append_common_sanitizer_flags()
600 append("-fsanitize=address,undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
601 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
603 message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
606 if (LLVM_USE_SANITIZER STREQUAL "Address")
607 append_common_sanitizer_flags()
608 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
610 message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}")
613 message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.")
615 if (LLVM_USE_SANITIZER MATCHES "(Undefined;)?Address(;Undefined)?")
616 add_flag_if_supported("-fsanitize-address-use-after-scope"
617 FSANITIZE_USE_AFTER_SCOPE_FLAG)
619 if (LLVM_USE_SANITIZE_COVERAGE)
620 append("-fsanitize-coverage=trace-pc-guard,indirect-calls,trace-cmp" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
624 # Turn on -gsplit-dwarf if requested
625 if(LLVM_USE_SPLIT_DWARF)
626 add_definitions("-gsplit-dwarf")
629 add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
630 add_llvm_definitions( -D__STDC_FORMAT_MACROS )
631 add_llvm_definitions( -D__STDC_LIMIT_MACROS )
633 # clang doesn't print colored diagnostics when invoked from Ninja
635 CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
636 CMAKE_GENERATOR STREQUAL "Ninja")
637 append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
640 # lld doesn't print colored diagnostics when invoked from Ninja
641 if (UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")
642 include(CheckLinkerFlag)
643 check_linker_flag("-Wl,-color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
644 append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,-color-diagnostics"
645 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
648 # Add flags for add_dead_strip().
649 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
650 # But MinSizeRel seems to add that automatically, so maybe disable these
651 # flags instead if LLVM_NO_DEAD_STRIP is set.
652 if(NOT CYGWIN AND NOT WIN32)
653 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
654 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
655 check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
656 if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
657 # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
658 # Doing so will break sanitizers.
659 add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
661 add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
666 # Remove flags here, for exceptions and RTTI.
667 # Each target property or source property should be responsible to control
669 # CL.EXE complains to override flags like "/GR /GR-".
670 string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
671 string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
674 # Provide public options to globally control RTTI and EH
675 option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
676 option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
677 if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
678 message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
681 option(LLVM_BUILD_INSTRUMENTED "Build LLVM and tools with PGO instrumentation (experimental)" Off)
682 mark_as_advanced(LLVM_BUILD_INSTRUMENTED)
683 append_if(LLVM_BUILD_INSTRUMENTED "-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}'"
686 CMAKE_EXE_LINKER_FLAGS
687 CMAKE_SHARED_LINKER_FLAGS)
689 option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation (experimental)" Off)
690 mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE)
691 append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}' -fcoverage-mapping"
694 CMAKE_EXE_LINKER_FLAGS
695 CMAKE_SHARED_LINKER_FLAGS)
697 set(LLVM_ENABLE_LTO OFF CACHE STRING "Build LLVM with LTO. May be specified as Thin or Full to use a particular kind of LTO")
698 string(TOUPPER "${LLVM_ENABLE_LTO}" uppercase_LLVM_ENABLE_LTO)
699 if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
700 append("-flto=thin" CMAKE_CXX_FLAGS CMAKE_C_FLAGS
701 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
702 # On darwin, enable the lto cache. This improves initial build time a little
703 # since we re-link a lot of the same objects, and significantly improves
704 # incremental build time.
705 append_if(APPLE "-Wl,-cache_path_lto,${PROJECT_BINARY_DIR}/lto.cache"
706 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
707 elseif(uppercase_LLVM_ENABLE_LTO STREQUAL "FULL")
708 append("-flto=full" CMAKE_CXX_FLAGS CMAKE_C_FLAGS
709 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
710 elseif(LLVM_ENABLE_LTO)
711 append("-flto" CMAKE_CXX_FLAGS CMAKE_C_FLAGS
712 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
715 # This option makes utils/extract_symbols.py be used to determine the list of
716 # symbols to export from LLVM tools. This is necessary when using MSVC if you
717 # want to allow plugins, though note that the plugin has to explicitly link
718 # against (exactly one) tool so we can't unilaterally turn on
719 # LLVM_ENABLE_PLUGINS when it's enabled.
720 option(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS "Export symbols from LLVM tools so that plugins can import them" OFF)
721 if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
722 message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
724 if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
725 message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
729 # FIXME: Make this configurable.
731 if(BUILD_SHARED_LIBS)
732 set(LLVM_ENABLE_PLUGINS ON)
734 set(LLVM_ENABLE_PLUGINS OFF)
737 set(LLVM_ENABLE_PLUGINS ON)