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 include(HandleLLVMStdlib)
6 include(AddLLVMDefinitions)
7 include(CheckCCompilerFlag)
8 include(CheckCXXCompilerFlag)
10 if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
11 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
12 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
13 message(FATAL_ERROR "Host GCC version must be at least 4.7!")
15 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
16 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
17 message(FATAL_ERROR "Host Clang version must be at least 3.1!")
20 # Also test that we aren't using too old of a version of libstdc++ with the
21 # Clang compiler. This is tricky as there is no real way to check the
22 # version of libstdc++ directly. Instead we test for a known bug in
23 # libstdc++4.6 that is fixed in libstdc++4.7.
24 if(NOT LLVM_ENABLE_LIBCXX)
25 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
26 set(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
27 set(CMAKE_REQUIRED_FLAGS "-std=c++0x")
29 set(CMAKE_REQUIRED_LIBRARIES "atomic")
31 check_cxx_source_compiles("
33 std::atomic<float> x(0.0f);
34 int main() { return (float)x; }"
35 LLVM_NO_OLD_LIBSTDCXX)
36 if(NOT LLVM_NO_OLD_LIBSTDCXX)
37 message(FATAL_ERROR "Host Clang must be able to find libstdc++4.7 or newer!")
39 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
40 set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
42 elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
43 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17.0)
44 message(FATAL_ERROR "Host Visual Studio must be at least 2012 (MSVC 17.0)")
49 if( LLVM_ENABLE_ASSERTIONS )
50 # MSVC doesn't like _DEBUG on release builds. See PR 4379.
52 add_definitions( -D_DEBUG )
54 # On non-Debug builds cmake automatically defines NDEBUG, so we
55 # explicitly undefine it:
56 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
57 add_definitions( -UNDEBUG )
58 # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
59 set(REGEXP_NDEBUG "(^| )[/-]D *NDEBUG($| )")
60 string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
61 CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
62 string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
63 CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
64 string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
65 CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL}")
68 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" )
69 if( NOT MSVC_IDE AND NOT XCODE )
70 add_definitions( -DNDEBUG )
76 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
84 # Maximum path length is 160 for non-unicode paths
91 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
93 set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
95 # FIXME: Maximum path length is currently set to 'safe' fixed value
98 MESSAGE(SEND_ERROR "Unable to determine platform")
102 set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
103 set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
105 # We use *.dylib rather than *.so on darwin.
106 set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
109 # Darwin-specific linker flags for loadable modules.
110 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
113 function(add_flag_or_print_warning flag)
114 check_c_compiler_flag(${flag} C_SUPPORTS_FLAG)
115 check_cxx_compiler_flag(${flag} CXX_SUPPORTS_FLAG)
116 if (C_SUPPORTS_FLAG AND CXX_SUPPORTS_FLAG)
117 message(STATUS "Building with ${flag}")
118 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
119 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
121 message(WARNING "${flag} is not supported.")
125 function(append value)
126 foreach(variable ${ARGN})
127 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
131 function(append_if condition value)
133 foreach(variable ${ARGN})
134 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
139 macro(add_flag_if_supported flag)
140 check_c_compiler_flag(${flag} C_SUPPORTS_FLAG)
141 append_if(C_SUPPORTS_FLAG "${flag}" CMAKE_C_FLAGS)
142 check_cxx_compiler_flag(${flag} CXX_SUPPORTS_FLAG)
143 append_if(CXX_SUPPORTS_FLAG "${flag}" CMAKE_CXX_FLAGS)
146 if( LLVM_ENABLE_PIC )
148 # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
149 # know how to disable this, so just force ENABLE_PIC off for now.
150 message(WARNING "-fPIC not supported with Xcode.")
151 elseif( WIN32 OR CYGWIN)
152 # On Windows all code is PIC. MinGW warns if -fPIC is used.
154 add_flag_or_print_warning("-fPIC")
157 # MinGW warns if -fvisibility-inlines-hidden is used.
159 check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
160 append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
165 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
166 # TODO: support other platforms and toolchains.
167 if( LLVM_BUILD_32_BITS )
168 message(STATUS "Building 32 bits executables and libraries.")
169 add_llvm_definitions( -m32 )
170 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
171 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
172 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
173 endif( LLVM_BUILD_32_BITS )
174 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
177 # For Xcode enable several build settings that correspond to
178 # many warnings that are on by default in Clang but are
179 # not enabled for historical reasons. For versions of Xcode
180 # that do not support these options they will simply
182 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
183 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
184 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
185 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
186 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
187 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
188 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
189 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
190 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
191 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
192 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
193 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
194 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
195 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
196 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
199 # On Win32 using MS tools, provide an option to set the number of parallel jobs
202 set(LLVM_COMPILER_JOBS "0" CACHE STRING
203 "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
204 if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
205 if( LLVM_COMPILER_JOBS STREQUAL "0" )
206 add_llvm_definitions( /MP )
208 message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
209 add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
212 message(STATUS "Parallel compilation disabled")
217 include(ChooseMSVCCRT)
219 if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
220 # set stack reserved size to ~10MB
221 # CMake previously automatically set this value for MSVC builds, but the
222 # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
223 # value (1 MB) which is not enough for us in tasks such as parsing recursive
224 # C++ templates in Clang.
225 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
229 add_llvm_definitions(-D_VARIADIC_MAX=10)
232 # Add definitions that make MSVC much less annoying.
233 add_llvm_definitions(
234 # For some reason MS wants to deprecate a bunch of standard functions...
235 -D_CRT_SECURE_NO_DEPRECATE
236 -D_CRT_SECURE_NO_WARNINGS
237 -D_CRT_NONSTDC_NO_DEPRECATE
238 -D_CRT_NONSTDC_NO_WARNINGS
239 -D_SCL_SECURE_NO_DEPRECATE
240 -D_SCL_SECURE_NO_WARNINGS
243 -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
244 -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
245 -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
246 -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
247 -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
248 -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
249 -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
250 -wd4355 # Suppress ''this' : used in base member initializer list'
251 -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
252 -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
253 -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
254 -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
257 -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
259 # Promoted warnings to errors.
260 -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
264 if (LLVM_ENABLE_WARNINGS)
265 add_llvm_definitions( /W4 )
266 if (LLVM_ENABLE_PEDANTIC)
267 # No MSVC equivalent available
268 endif (LLVM_ENABLE_PEDANTIC)
269 endif (LLVM_ENABLE_WARNINGS)
270 if (LLVM_ENABLE_WERROR)
271 add_llvm_definitions( /WX )
272 endif (LLVM_ENABLE_WERROR)
273 elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
274 if (LLVM_ENABLE_WARNINGS)
275 append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
277 # Turn off missing field initializer warnings for gcc to avoid noise from
278 # false positives with empty {}. Turn them on otherwise (they're off by
279 # default for clang).
280 check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
281 if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
282 if (CMAKE_COMPILER_IS_GNUCXX)
283 append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
285 append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
289 append_if(LLVM_ENABLE_PEDANTIC "-pedantic -Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
290 check_cxx_compiler_flag("-Werror -Wcovered-switch-default" CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
291 append_if(CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG "-Wcovered-switch-default" CMAKE_CXX_FLAGS)
292 check_c_compiler_flag("-Werror -Wcovered-switch-default" C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
293 append_if(C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG "-Wcovered-switch-default" CMAKE_C_FLAGS)
294 append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
295 append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
296 check_cxx_compiler_flag("-Werror -Wnon-virtual-dtor" CXX_SUPPORTS_NON_VIRTUAL_DTOR_FLAG)
297 append_if(CXX_SUPPORTS_NON_VIRTUAL_DTOR_FLAG "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
298 endif (LLVM_ENABLE_WARNINGS)
299 append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
300 if (LLVM_ENABLE_CXX1Y)
301 check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
302 append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
304 check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
305 if (CXX_SUPPORTS_CXX11)
307 # MinGW and Cygwin are a bit stricter and lack things like
308 # 'strdup', 'stricmp', etc in c++11 mode.
309 append("-std=gnu++11" CMAKE_CXX_FLAGS)
311 append("-std=c++11" CMAKE_CXX_FLAGS)
314 message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
319 macro(append_common_sanitizer_flags)
320 # Append -fno-omit-frame-pointer and turn on debug info to get better
322 add_flag_if_supported("-fno-omit-frame-pointer")
323 if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
324 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
325 add_flag_if_supported("-gline-tables-only")
327 # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
328 if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
329 add_flag_if_supported("-O1")
333 # Turn on sanitizers if necessary.
334 if(LLVM_USE_SANITIZER)
336 if (LLVM_USE_SANITIZER STREQUAL "Address")
337 append_common_sanitizer_flags()
338 add_flag_or_print_warning("-fsanitize=address")
339 elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
340 append_common_sanitizer_flags()
341 add_flag_or_print_warning("-fsanitize=memory")
342 if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
343 add_flag_or_print_warning("-fsanitize-memory-track-origins")
346 message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
349 message(WARNING "LLVM_USE_SANITIZER is not supported on this platform.")
353 # Turn on -gsplit-dwarf if requested
354 if(LLVM_USE_SPLIT_DWARF)
355 add_llvm_definitions("-gsplit-dwarf")
358 add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
359 add_llvm_definitions( -D__STDC_FORMAT_MACROS )
360 add_llvm_definitions( -D__STDC_LIMIT_MACROS )
362 # clang doesn't print colored diagnostics when invoked from Ninja
364 CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
365 CMAKE_GENERATOR STREQUAL "Ninja")
366 append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
369 # Add flags for add_dead_strip().
370 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
371 # But MinSizeRel seems to add that automatically, so maybe disable these
372 # flags instead if LLVM_NO_DEAD_STRIP is set.
373 if(NOT CYGWIN AND NOT WIN32)
374 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
375 check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
376 if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
377 # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
378 # Doing so will break sanitizers.
379 check_c_compiler_flag("-Werror -ffunction-sections" C_SUPPORTS_FFUNCTION_SECTIONS)
380 check_cxx_compiler_flag("-Werror -ffunction-sections" CXX_SUPPORTS_FFUNCTION_SECTIONS)
381 append_if(C_SUPPORTS_FFUNCTION_SECTIONS "-ffunction-sections" CMAKE_C_FLAGS)
382 append_if(CXX_SUPPORTS_FFUNCTION_SECTIONS "-ffunction-sections" CMAKE_CXX_FLAGS)
384 check_c_compiler_flag("-Werror -fdata-sections" C_SUPPORTS_FDATA_SECTIONS)
385 check_cxx_compiler_flag("-Werror -fdata-sections" CXX_SUPPORTS_FDATA_SECTIONS)
386 append_if(C_SUPPORTS_FDATA_SECTIONS "-fdata-sections" CMAKE_C_FLAGS)
387 append_if(CXX_SUPPORTS_FDATA_SECTIONS "-fdata-sections" CMAKE_CXX_FLAGS)
392 # Prune --out-implib from executables. It doesn't make sense even
393 # with --export-all-symbols.
394 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
395 CMAKE_C_LINK_EXECUTABLE "${CMAKE_C_LINK_EXECUTABLE}")
396 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
397 CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_CXX_LINK_EXECUTABLE}")
401 # Remove flags here, for exceptions and RTTI.
402 # Each target property or source property should be responsible to control
404 # CL.EXE complains to override flags like "/GR /GR-".
405 string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
406 string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")