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")
28 check_cxx_source_compiles("
30 std::atomic<float> x(0.0f);
31 int main() { return (float)x; }"
32 LLVM_NO_OLD_LIBSTDCXX)
33 if(NOT LLVM_NO_OLD_LIBSTDCXX)
34 message(FATAL_ERROR "Host Clang must be able to find libstdc++4.7 or newer!")
36 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
37 set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
39 elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
40 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17.0)
41 message(FATAL_ERROR "Host Visual Studio must be at least 2012 (MSVC 17.0)")
46 if( LLVM_ENABLE_ASSERTIONS )
47 # MSVC doesn't like _DEBUG on release builds. See PR 4379.
49 add_definitions( -D_DEBUG )
51 # On non-Debug builds cmake automatically defines NDEBUG, so we
52 # explicitly undefine it:
53 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
54 add_definitions( -UNDEBUG )
55 # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
56 foreach (flags_var_to_scrub
57 CMAKE_CXX_FLAGS_RELEASE
58 CMAKE_CXX_FLAGS_RELWITHDEBINFO
59 CMAKE_CXX_FLAGS_MINSIZEREL
61 CMAKE_C_FLAGS_RELWITHDEBINFO
62 CMAKE_C_FLAGS_MINSIZEREL)
63 string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
64 "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
70 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
78 # Maximum path length is 160 for non-unicode paths
85 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
87 set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
89 # FIXME: Maximum path length is currently set to 'safe' fixed value
92 MESSAGE(SEND_ERROR "Unable to determine platform")
96 set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
97 set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
99 # We use *.dylib rather than *.so on darwin.
100 set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
103 # Darwin-specific linker flags for loadable modules.
104 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
107 function(append value)
108 foreach(variable ${ARGN})
109 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
113 function(append_if condition value)
115 foreach(variable ${ARGN})
116 set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
121 macro(add_flag_if_supported flag name)
122 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
123 append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
124 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
125 append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
128 function(add_flag_or_print_warning flag name)
129 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
130 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
131 if ("C_SUPPORTS_${name}" AND "CXX_SUPPORTS_${name}")
132 message(STATUS "Building with ${flag}")
133 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
134 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
136 message(WARNING "${flag} is not supported.")
140 if( LLVM_ENABLE_PIC )
142 # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
143 # know how to disable this, so just force ENABLE_PIC off for now.
144 message(WARNING "-fPIC not supported with Xcode.")
145 elseif( WIN32 OR CYGWIN)
146 # On Windows all code is PIC. MinGW warns if -fPIC is used.
148 add_flag_or_print_warning("-fPIC" FPIC)
151 # MinGW warns if -fvisibility-inlines-hidden is used.
153 check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
154 append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
159 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
160 # TODO: support other platforms and toolchains.
161 if( LLVM_BUILD_32_BITS )
162 message(STATUS "Building 32 bits executables and libraries.")
163 add_llvm_definitions( -m32 )
164 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
165 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
166 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
167 endif( LLVM_BUILD_32_BITS )
168 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
171 # For Xcode enable several build settings that correspond to
172 # many warnings that are on by default in Clang but are
173 # not enabled for historical reasons. For versions of Xcode
174 # that do not support these options they will simply
176 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
177 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
178 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
179 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
180 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
181 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
182 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
183 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
184 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
185 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
186 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
187 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
188 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
189 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
190 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
193 # On Win32 using MS tools, provide an option to set the number of parallel jobs
196 set(LLVM_COMPILER_JOBS "0" CACHE STRING
197 "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
198 if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
199 if( LLVM_COMPILER_JOBS STREQUAL "0" )
200 add_llvm_definitions( /MP )
202 message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
203 add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
206 message(STATUS "Parallel compilation disabled")
211 include(ChooseMSVCCRT)
213 if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
214 # set stack reserved size to ~10MB
215 # CMake previously automatically set this value for MSVC builds, but the
216 # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
217 # value (1 MB) which is not enough for us in tasks such as parsing recursive
218 # C++ templates in Clang.
219 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
223 add_llvm_definitions(-D_VARIADIC_MAX=10)
226 # Add definitions that make MSVC much less annoying.
227 add_llvm_definitions(
228 # For some reason MS wants to deprecate a bunch of standard functions...
229 -D_CRT_SECURE_NO_DEPRECATE
230 -D_CRT_SECURE_NO_WARNINGS
231 -D_CRT_NONSTDC_NO_DEPRECATE
232 -D_CRT_NONSTDC_NO_WARNINGS
233 -D_SCL_SECURE_NO_DEPRECATE
234 -D_SCL_SECURE_NO_WARNINGS
237 -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
238 -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
239 -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
240 -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
241 -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
242 -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
243 -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
244 -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
245 -wd4355 # Suppress ''this' : used in base member initializer list'
246 -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
247 -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
248 -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
249 -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
252 -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
254 # Promoted warnings to errors.
255 -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
259 if (LLVM_ENABLE_WARNINGS)
260 add_llvm_definitions( /W4 )
261 if (LLVM_ENABLE_PEDANTIC)
262 # No MSVC equivalent available
263 endif (LLVM_ENABLE_PEDANTIC)
264 endif (LLVM_ENABLE_WARNINGS)
265 if (LLVM_ENABLE_WERROR)
266 add_llvm_definitions( /WX )
267 endif (LLVM_ENABLE_WERROR)
268 elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
269 if (LLVM_ENABLE_WARNINGS)
270 append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
272 # Turn off missing field initializer warnings for gcc to avoid noise from
273 # false positives with empty {}. Turn them on otherwise (they're off by
274 # default for clang).
275 check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
276 if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
277 if (CMAKE_COMPILER_IS_GNUCXX)
278 append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
280 append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
284 append_if(LLVM_ENABLE_PEDANTIC "-pedantic -Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
285 add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
286 append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
287 append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
289 # Check if -Wnon-virtual-dtor warns even though the class is marked final.
290 # If it does, don't add it. So it won't be added on clang 3.4 and older.
291 # This also catches cases when -Wnon-virtual-dtor isn't supported by
292 # the compiler at all.
293 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
294 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor")
295 CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();};
296 class derived final : public base { public: ~derived();};
297 int main() { return 0; }"
298 CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
299 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
300 append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR
301 "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
303 # Check if -Wcomment is OK with an // comment ending with '\' if the next
304 # line is also a // comment.
305 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
306 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
307 CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}"
308 C_WCOMMENT_ALLOWS_LINE_WRAP)
309 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
310 if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
311 append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
313 endif (LLVM_ENABLE_WARNINGS)
314 append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
315 if (NOT LLVM_ENABLE_TIMESTAMPS)
316 add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
318 if (LLVM_ENABLE_CXX1Y)
319 check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
320 append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
322 check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11)
323 if (CXX_SUPPORTS_CXX11)
325 # MinGW and Cygwin are a bit stricter and lack things like
326 # 'strdup', 'stricmp', etc in c++11 mode.
327 append("-std=gnu++11" CMAKE_CXX_FLAGS)
329 append("-std=c++11" CMAKE_CXX_FLAGS)
332 message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.")
337 macro(append_common_sanitizer_flags)
338 # Append -fno-omit-frame-pointer and turn on debug info to get better
340 add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
341 if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
342 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
343 add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
345 # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
346 if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
347 add_flag_if_supported("-O1" O1)
351 # Turn on sanitizers if necessary.
352 if(LLVM_USE_SANITIZER)
354 if (LLVM_USE_SANITIZER STREQUAL "Address")
355 append_common_sanitizer_flags()
356 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
357 elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
358 append_common_sanitizer_flags()
359 append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
360 if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
361 append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
363 elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
364 append_common_sanitizer_flags()
365 append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover"
366 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
368 message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
371 message(WARNING "LLVM_USE_SANITIZER is not supported on this platform.")
375 # Turn on -gsplit-dwarf if requested
376 if(LLVM_USE_SPLIT_DWARF)
377 add_llvm_definitions("-gsplit-dwarf")
380 add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
381 add_llvm_definitions( -D__STDC_FORMAT_MACROS )
382 add_llvm_definitions( -D__STDC_LIMIT_MACROS )
384 # clang doesn't print colored diagnostics when invoked from Ninja
386 CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
387 CMAKE_GENERATOR STREQUAL "Ninja")
388 append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
391 # Add flags for add_dead_strip().
392 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
393 # But MinSizeRel seems to add that automatically, so maybe disable these
394 # flags instead if LLVM_NO_DEAD_STRIP is set.
395 if(NOT CYGWIN AND NOT WIN32)
396 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
397 check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
398 if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
399 # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
400 # Doing so will break sanitizers.
401 add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
403 add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
408 # Prune --out-implib from executables. It doesn't make sense even
409 # with --export-all-symbols.
410 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
411 CMAKE_C_LINK_EXECUTABLE "${CMAKE_C_LINK_EXECUTABLE}")
412 string(REGEX REPLACE "-Wl,--out-implib,[^ ]+ " " "
413 CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_CXX_LINK_EXECUTABLE}")
417 # Remove flags here, for exceptions and RTTI.
418 # Each target property or source property should be responsible to control
420 # CL.EXE complains to override flags like "/GR /GR-".
421 string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
422 string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
425 # Provide public options to globally control RTTI and EH
426 option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
427 option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
428 if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
429 message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
433 # FIXME: Make this configurable.
435 if(BUILD_SHARED_LIBS)
436 set(LLVM_ENABLE_PLUGINS ON)
438 set(LLVM_ENABLE_PLUGINS OFF)
441 set(LLVM_ENABLE_PLUGINS ON)