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(HandleLLVMStdlib)
10 include(AddLLVMDefinitions)
11 include(CheckCCompilerFlag)
12 include(CheckCXXCompilerFlag)
14 if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
15 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
16 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
17 message(FATAL_ERROR "Host GCC version must be at least 4.7!")
19 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
20 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
21 message(FATAL_ERROR "Host Clang version must be at least 3.1!")
24 if (CMAKE_CXX_SIMULATE_ID MATCHES "MSVC")
25 if (CMAKE_CXX_SIMULATE_VERSION VERSION_LESS 18.0)
26 message(FATAL_ERROR "Host Clang must have at least -fms-compatibility-version=18.0")
29 elseif(NOT LLVM_ENABLE_LIBCXX)
30 # Otherwise, test that we aren't using too old of a version of libstdc++
31 # with the Clang compiler. This is tricky as there is no real way to
32 # check the version of libstdc++ directly. Instead we test for a known
33 # bug in libstdc++4.6 that is fixed in libstdc++4.7.
34 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
35 set(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
36 set(CMAKE_REQUIRED_FLAGS "-std=c++0x")
37 check_cxx_source_compiles("
39 std::atomic<float> x(0.0f);
40 int main() { return (float)x; }"
41 LLVM_NO_OLD_LIBSTDCXX)
42 if(NOT LLVM_NO_OLD_LIBSTDCXX)
43 message(FATAL_ERROR "Host Clang must be able to find libstdc++4.7 or newer!")
45 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
46 set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
48 elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
49 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 18.0)
50 message(FATAL_ERROR "Host Visual Studio must be at least 2013")
51 elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 18.0.31101)
52 message(WARNING "Host Visual Studio should at least be 2013 Update 4 (MSVC 18.0.31101)"
53 " due to miscompiles from earlier versions")
58 if( LLVM_ENABLE_ASSERTIONS )
59 # MSVC doesn't like _DEBUG on release builds. See PR 4379.
61 add_definitions( -D_DEBUG )
63 # On non-Debug builds cmake automatically defines NDEBUG, so we
64 # explicitly undefine it:
65 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
66 add_definitions( -UNDEBUG )
67 # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
68 foreach (flags_var_to_scrub
69 CMAKE_CXX_FLAGS_RELEASE
70 CMAKE_CXX_FLAGS_RELWITHDEBINFO
71 CMAKE_CXX_FLAGS_MINSIZEREL
73 CMAKE_C_FLAGS_RELWITHDEBINFO
74 CMAKE_C_FLAGS_MINSIZEREL)
75 string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
76 "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
81 string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
83 if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" )
84 if( LLVM_ENABLE_ASSERTIONS )
85 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
87 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" )
88 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
89 elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
90 # We don't need to do anything special to turn off ABI breaking checks.
91 elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS )
92 # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been
95 message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
99 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
112 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
114 set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
117 MESSAGE(SEND_ERROR "Unable to determine platform")
121 set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
122 set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
124 # We use *.dylib rather than *.so on darwin.
125 set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
128 # Darwin-specific linker flags for loadable modules.
129 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
132 # Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
133 # build might work on ELF but fail on MachO/COFF.
134 if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR
135 ${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD" OR
136 ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD") AND
137 NOT LLVM_USE_SANITIZER)
138 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
142 function(append value)
143 foreach(variable ${ARGN})
144 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
148 function(append_if condition value)
150 foreach(variable ${ARGN})
151 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
156 macro(add_flag_if_supported flag name)
157 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
158 append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
159 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
160 append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
163 function(add_flag_or_print_warning flag name)
164 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
165 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
166 if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
167 message(STATUS "Building with ${flag}")
168 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
169 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
170 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE)
172 message(WARNING "${flag} is not supported.")
176 if( LLVM_ENABLE_PIC )
178 # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
179 # know how to disable this, so just force ENABLE_PIC off for now.
180 message(WARNING "-fPIC not supported with Xcode.")
181 elseif( WIN32 OR CYGWIN)
182 # On Windows all code is PIC. MinGW warns if -fPIC is used.
184 add_flag_or_print_warning("-fPIC" FPIC)
188 if(NOT WIN32 AND NOT CYGWIN)
189 # MinGW warns if -fvisibility-inlines-hidden is used.
190 check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
191 append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
194 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
195 # TODO: support other platforms and toolchains.
196 if( LLVM_BUILD_32_BITS )
197 message(STATUS "Building 32 bits executables and libraries.")
198 add_llvm_definitions( -m32 )
199 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
200 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
201 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
202 endif( LLVM_BUILD_32_BITS )
203 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
205 if (LLVM_BUILD_STATIC)
206 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
210 # For Xcode enable several build settings that correspond to
211 # many warnings that are on by default in Clang but are
212 # not enabled for historical reasons. For versions of Xcode
213 # that do not support these options they will simply
215 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
216 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
217 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
218 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
219 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
220 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
221 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
222 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
223 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
224 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
225 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
226 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
227 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
228 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
229 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
232 # On Win32 using MS tools, provide an option to set the number of parallel jobs
235 set(LLVM_COMPILER_JOBS "0" CACHE STRING
236 "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
237 if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
238 if( LLVM_COMPILER_JOBS STREQUAL "0" )
239 add_llvm_definitions( /MP )
241 message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
242 add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
245 message(STATUS "Parallel compilation disabled")
250 if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 )
251 # For MSVC 2013, disable iterator null pointer checking in debug mode,
252 # especially so std::equal(nullptr, nullptr, nullptr) will not assert.
253 add_llvm_definitions("-D_DEBUG_POINTER_IMPL=")
256 include(ChooseMSVCCRT)
258 if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
259 # set stack reserved size to ~10MB
260 # CMake previously automatically set this value for MSVC builds, but the
261 # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
262 # value (1 MB) which is not enough for us in tasks such as parsing recursive
263 # C++ templates in Clang.
264 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
268 add_llvm_definitions(-D_VARIADIC_MAX=10)
271 # Add definitions that make MSVC much less annoying.
272 add_llvm_definitions(
273 # For some reason MS wants to deprecate a bunch of standard functions...
274 -D_CRT_SECURE_NO_DEPRECATE
275 -D_CRT_SECURE_NO_WARNINGS
276 -D_CRT_NONSTDC_NO_DEPRECATE
277 -D_CRT_NONSTDC_NO_WARNINGS
278 -D_SCL_SECURE_NO_DEPRECATE
279 -D_SCL_SECURE_NO_WARNINGS
282 set(msvc_warning_flags
284 -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline)
285 -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
286 -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
287 -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
288 -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
289 -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
290 -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
291 -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
292 -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
293 -wd4355 # Suppress ''this' : used in base member initializer list'
294 -wd4456 # Suppress 'declaration of 'var' hides local variable'
295 -wd4457 # Suppress 'declaration of 'var' hides function parameter'
296 -wd4458 # Suppress 'declaration of 'var' hides class member'
297 -wd4459 # Suppress 'declaration of 'var' hides global declaration'
298 -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
299 -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
300 -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
301 -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
302 -wd4100 # Suppress 'unreferenced formal parameter'
303 -wd4127 # Suppress 'conditional expression is constant'
304 -wd4512 # Suppress 'assignment operator could not be generated'
305 -wd4505 # Suppress 'unreferenced local function has been removed'
306 -wd4610 # Suppress '<class> can never be instantiated'
307 -wd4510 # Suppress 'default constructor could not be generated'
308 -wd4702 # Suppress 'unreachable code'
309 -wd4245 # Suppress 'signed/unsigned mismatch'
310 -wd4706 # Suppress 'assignment within conditional expression'
311 -wd4310 # Suppress 'cast truncates constant value'
312 -wd4701 # Suppress 'potentially uninitialized local variable'
313 -wd4703 # Suppress 'potentially uninitialized local pointer variable'
314 -wd4389 # Suppress 'signed/unsigned mismatch'
315 -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable'
316 -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation'
317 -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer'
318 -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed'
319 -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared'
320 # C4592 is disabled because of false positives in Visual Studio 2015
321 # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2.
322 -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation)
324 # Ideally, we'd like this warning to be enabled, but MSVC 2013 doesn't
325 # support the 'aligned' attribute in the way that clang sources requires (for
326 # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to
327 # avoid unwanted alignment warnings.
328 # When we switch to requiring a version of MSVC that supports the 'alignas'
329 # specifier (MSVC 2015?) this warning can be re-enabled.
330 -wd4324 # Suppress 'structure was padded due to __declspec(align())'
333 -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
335 # Promoted warnings to errors.
336 -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
340 if (LLVM_ENABLE_WARNINGS)
341 append("/W4" msvc_warning_flags)
342 # CMake appends /W3 by default, and having /W3 followed by /W4 will result in
343 # cl : Command line warning D9025 : overriding '/W3' with '/W4'. Since this is
344 # a command line warning and not a compiler warning, it cannot be suppressed except
345 # by fixing the command line.
346 string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
347 string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
349 if (LLVM_ENABLE_PEDANTIC)
350 # No MSVC equivalent available
351 endif (LLVM_ENABLE_PEDANTIC)
352 endif (LLVM_ENABLE_WARNINGS)
353 if (LLVM_ENABLE_WERROR)
354 append("/WX" msvc_warning_flags)
355 endif (LLVM_ENABLE_WERROR)
357 foreach(flag ${msvc_warning_flags})
358 append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
361 append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
363 # Disable sized deallocation if the flag is supported. MSVC fails to compile
364 # the operator new overload in User otherwise.
365 check_c_compiler_flag("/WX /Zc:sizedDealloc-" SUPPORTS_SIZED_DEALLOC)
366 append_if(SUPPORTS_SIZED_DEALLOC "/Zc:sizedDealloc-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
368 elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
369 if (LLVM_ENABLE_WARNINGS)
370 append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
371 append("-Wcast-qual" CMAKE_CXX_FLAGS)
373 # Turn off missing field initializer warnings for gcc to avoid noise from
374 # false positives with empty {}. Turn them on otherwise (they're off by
375 # default for clang).
376 check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
377 if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
378 if (CMAKE_COMPILER_IS_GNUCXX)
379 append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
381 append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
385 append_if(LLVM_ENABLE_PEDANTIC "-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
386 append_if(LLVM_ENABLE_PEDANTIC "-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
387 add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
388 append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
389 append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
391 # Check if -Wnon-virtual-dtor warns even though the class is marked final.
392 # If it does, don't add it. So it won't be added on clang 3.4 and older.
393 # This also catches cases when -Wnon-virtual-dtor isn't supported by
394 # the compiler at all.
395 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
396 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor")
397 CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();};
398 class derived final : public base { public: ~derived();};
399 int main() { return 0; }"
400 CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
401 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
402 append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR
403 "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
405 # Check if -Wcomment is OK with an // comment ending with '\' if the next
406 # line is also a // comment.
407 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
408 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
409 CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}"
410 C_WCOMMENT_ALLOWS_LINE_WRAP)
411 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
412 if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
413 append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
415 endif (LLVM_ENABLE_WARNINGS)
416 append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
417 if (NOT LLVM_ENABLE_TIMESTAMPS)
418 add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
420 if (LLVM_ENABLE_CXX1Y)
421 check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
422 append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
424 check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
425 if (CXX_SUPPORTS_CXX11)
427 # MinGW and Cygwin are a bit stricter and lack things like
428 # 'strdup', 'stricmp', etc in c++11 mode.
429 append("-std=gnu++11" CMAKE_CXX_FLAGS)
431 append("-std=c++11" CMAKE_CXX_FLAGS)
434 message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
437 if (LLVM_ENABLE_MODULES)
438 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
439 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fmodules")
440 # Check that we can build code with modules enabled, and that repeatedly
441 # including <cassert> still manages to respect NDEBUG properly.
442 CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG
446 int main() { assert(this code is not compiled); }"
447 CXX_SUPPORTS_MODULES)
448 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
449 if (CXX_SUPPORTS_MODULES)
450 append_if(CXX_SUPPORTS_MODULES "-fmodules" CMAKE_C_FLAGS)
451 append_if(CXX_SUPPORTS_MODULES "-fmodules -fcxx-modules" CMAKE_CXX_FLAGS)
453 message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler")
455 endif(LLVM_ENABLE_MODULES)
458 macro(append_common_sanitizer_flags)
460 # Append -fno-omit-frame-pointer and turn on debug info to get better
462 add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
463 if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
464 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
465 add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
467 # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
468 if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
469 add_flag_if_supported("-O1" O1)
472 # Keep frame pointers around.
473 append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
474 if (CMAKE_LINKER MATCHES "lld-link.exe")
475 # Use DWARF debug info with LLD.
476 append("-gdwarf" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
477 # Pass /MANIFEST:NO so that CMake doesn't run mt.exe on our binaries.
478 # Adding manifests with mt.exe breaks LLD's symbol tables. See PR24476.
479 append("/MANIFEST:NO"
480 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
482 # Enable codeview otherwise.
483 append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
485 # Always ask the linker to produce symbols with asan.
486 append("-debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
490 # Turn on sanitizers if necessary.
491 if(LLVM_USE_SANITIZER)
493 if (LLVM_USE_SANITIZER STREQUAL "Address")
494 append_common_sanitizer_flags()
495 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
496 elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
497 append_common_sanitizer_flags()
498 append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
499 if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
500 append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
502 elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
503 append_common_sanitizer_flags()
504 append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
505 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
506 elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
507 append_common_sanitizer_flags()
508 append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
509 elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
510 LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
511 append_common_sanitizer_flags()
512 append("-fsanitize=address,undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all"
513 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
515 message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
518 if (LLVM_USE_SANITIZER STREQUAL "Address")
519 append_common_sanitizer_flags()
520 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
522 message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}")
525 message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.")
527 if (LLVM_USE_SANITIZE_COVERAGE)
528 append("-fsanitize-coverage=edge,indirect-calls,8bit-counters,trace-cmp" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
532 # Turn on -gsplit-dwarf if requested
533 if(LLVM_USE_SPLIT_DWARF)
534 add_definitions("-gsplit-dwarf")
537 add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
538 add_llvm_definitions( -D__STDC_FORMAT_MACROS )
539 add_llvm_definitions( -D__STDC_LIMIT_MACROS )
541 # clang doesn't print colored diagnostics when invoked from Ninja
543 CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
544 CMAKE_GENERATOR STREQUAL "Ninja")
545 append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
548 # Add flags for add_dead_strip().
549 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
550 # But MinSizeRel seems to add that automatically, so maybe disable these
551 # flags instead if LLVM_NO_DEAD_STRIP is set.
552 if(NOT CYGWIN AND NOT WIN32)
553 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
554 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
555 check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
556 if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
557 # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
558 # Doing so will break sanitizers.
559 add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
561 add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
566 # Prune --out-implib from executables. It doesn't make sense even
567 # with --export-all-symbols.
568 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
569 CMAKE_C_LINK_EXECUTABLE "${CMAKE_C_LINK_EXECUTABLE}")
570 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
571 CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_CXX_LINK_EXECUTABLE}")
575 # Remove flags here, for exceptions and RTTI.
576 # Each target property or source property should be responsible to control
578 # CL.EXE complains to override flags like "/GR /GR-".
579 string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
580 string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
583 # Provide public options to globally control RTTI and EH
584 option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
585 option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
586 if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
587 message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
590 option(LLVM_BUILD_INSTRUMENTED "Build LLVM and tools with PGO instrumentation (experimental)" Off)
591 mark_as_advanced(LLVM_BUILD_INSTRUMENTED)
592 append_if(LLVM_BUILD_INSTRUMENTED "-fprofile-instr-generate"
595 CMAKE_EXE_LINKER_FLAGS
596 CMAKE_SHARED_LINKER_FLAGS)
599 # FIXME: Make this configurable.
601 if(BUILD_SHARED_LIBS)
602 set(LLVM_ENABLE_PLUGINS ON)
604 set(LLVM_ENABLE_PLUGINS OFF)
607 set(LLVM_ENABLE_PLUGINS ON)