1# This CMake module is responsible for interpreting the user defined LLVM_ 2# options and executing the appropriate CMake commands to realize the users' 3# selections. 4 5# This is commonly needed so make sure it's defined before we include anything 6# else. 7string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE) 8 9include(CheckCompilerVersion) 10include(HandleLLVMStdlib) 11include(AddLLVMDefinitions) 12include(CheckCCompilerFlag) 13include(CheckCXXCompilerFlag) 14 15 16if (CMAKE_LINKER MATCHES "lld-link.exe") 17 # Pass /MANIFEST:NO so that CMake doesn't run mt.exe on our binaries. Adding 18 # manifests with mt.exe breaks LLD's symbol tables and takes as much time as 19 # the link. See PR24476. 20 append("/MANIFEST:NO" 21 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 22endif() 23 24if( LLVM_ENABLE_ASSERTIONS ) 25 # MSVC doesn't like _DEBUG on release builds. See PR 4379. 26 if( NOT MSVC ) 27 add_definitions( -D_DEBUG ) 28 endif() 29 # On non-Debug builds cmake automatically defines NDEBUG, so we 30 # explicitly undefine it: 31 if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" ) 32 add_definitions( -UNDEBUG ) 33 # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines. 34 foreach (flags_var_to_scrub 35 CMAKE_CXX_FLAGS_RELEASE 36 CMAKE_CXX_FLAGS_RELWITHDEBINFO 37 CMAKE_CXX_FLAGS_MINSIZEREL 38 CMAKE_C_FLAGS_RELEASE 39 CMAKE_C_FLAGS_RELWITHDEBINFO 40 CMAKE_C_FLAGS_MINSIZEREL) 41 string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " " 42 "${flags_var_to_scrub}" "${${flags_var_to_scrub}}") 43 endforeach() 44 endif() 45endif() 46 47if(LLVM_ENABLE_EXPENSIVE_CHECKS) 48 add_definitions(-DEXPENSIVE_CHECKS) 49 add_definitions(-D_GLIBCXX_DEBUG) 50endif() 51 52string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS) 53 54if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" ) 55 if( LLVM_ENABLE_ASSERTIONS ) 56 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 ) 57 endif() 58elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" ) 59 set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 ) 60elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" ) 61 # We don't need to do anything special to turn off ABI breaking checks. 62elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS ) 63 # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been 64 # defined. 65else() 66 message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!") 67endif() 68 69if(WIN32) 70 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0) 71 if(CYGWIN) 72 set(LLVM_ON_WIN32 0) 73 set(LLVM_ON_UNIX 1) 74 else(CYGWIN) 75 set(LLVM_ON_WIN32 1) 76 set(LLVM_ON_UNIX 0) 77 endif(CYGWIN) 78else(WIN32) 79 if(UNIX) 80 set(LLVM_ON_WIN32 0) 81 set(LLVM_ON_UNIX 1) 82 if(APPLE OR ${CMAKE_SYSTEM_NAME} MATCHES "AIX") 83 set(LLVM_HAVE_LINK_VERSION_SCRIPT 0) 84 else() 85 set(LLVM_HAVE_LINK_VERSION_SCRIPT 1) 86 endif() 87 else(UNIX) 88 MESSAGE(SEND_ERROR "Unable to determine platform") 89 endif(UNIX) 90endif(WIN32) 91 92set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX}) 93set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX}) 94 95# We use *.dylib rather than *.so on darwin. 96set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX}) 97 98if(APPLE) 99 if(LLVM_ENABLE_LLD AND LLVM_ENABLE_LTO) 100 message(FATAL_ERROR "lld does not support LTO on Darwin") 101 endif() 102 # Darwin-specific linker flags for loadable modules. 103 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress") 104endif() 105 106# Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO 107# build might work on ELF but fail on MachO/COFF. 108if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR 109 ${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD" OR 110 ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD") AND 111 NOT LLVM_USE_SANITIZER) 112 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs") 113endif() 114 115 116function(append value) 117 foreach(variable ${ARGN}) 118 set(${variable} "${${variable}} ${value}" PARENT_SCOPE) 119 endforeach(variable) 120endfunction() 121 122function(append_if condition value) 123 if (${condition}) 124 foreach(variable ${ARGN}) 125 set(${variable} "${${variable}} ${value}" PARENT_SCOPE) 126 endforeach(variable) 127 endif() 128endfunction() 129 130macro(add_flag_if_supported flag name) 131 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}") 132 append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS) 133 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}") 134 append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS) 135endmacro() 136 137function(add_flag_or_print_warning flag name) 138 check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}") 139 check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}") 140 if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name}) 141 message(STATUS "Building with ${flag}") 142 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE) 143 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE) 144 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE) 145 else() 146 message(WARNING "${flag} is not supported.") 147 endif() 148endfunction() 149 150if(LLVM_ENABLE_LLD) 151 check_cxx_compiler_flag("-fuse-ld=lld" CXX_SUPPORTS_LLD) 152 append_if(CXX_SUPPORTS_LLD "-fuse-ld=lld" 153 CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 154endif() 155 156if( LLVM_ENABLE_PIC ) 157 if( XCODE ) 158 # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't 159 # know how to disable this, so just force ENABLE_PIC off for now. 160 message(WARNING "-fPIC not supported with Xcode.") 161 elseif( WIN32 OR CYGWIN) 162 # On Windows all code is PIC. MinGW warns if -fPIC is used. 163 else() 164 add_flag_or_print_warning("-fPIC" FPIC) 165 endif() 166endif() 167 168if(NOT WIN32 AND NOT CYGWIN) 169 # MinGW warns if -fvisibility-inlines-hidden is used. 170 check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG) 171 append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS) 172endif() 173 174if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 ) 175 # TODO: support other platforms and toolchains. 176 if( LLVM_BUILD_32_BITS ) 177 message(STATUS "Building 32 bits executables and libraries.") 178 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32") 179 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32") 180 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32") 181 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32") 182 set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32") 183 endif( LLVM_BUILD_32_BITS ) 184endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 ) 185 186if( XCODE ) 187 # For Xcode enable several build settings that correspond to 188 # many warnings that are on by default in Clang but are 189 # not enabled for historical reasons. For versions of Xcode 190 # that do not support these options they will simply 191 # be ignored. 192 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES") 193 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES") 194 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES") 195 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES") 196 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES") 197 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES") 198 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES") 199 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES") 200 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES") 201 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES") 202 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES") 203 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES") 204 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES") 205 set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES") 206 set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES") 207endif() 208 209# On Win32 using MS tools, provide an option to set the number of parallel jobs 210# to use. 211if( MSVC_IDE ) 212 set(LLVM_COMPILER_JOBS "0" CACHE STRING 213 "Number of parallel compiler jobs. 0 means use all processors. Default is 0.") 214 if( NOT LLVM_COMPILER_JOBS STREQUAL "1" ) 215 if( LLVM_COMPILER_JOBS STREQUAL "0" ) 216 add_llvm_definitions( /MP ) 217 else() 218 message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS}) 219 add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} ) 220 endif() 221 else() 222 message(STATUS "Parallel compilation disabled") 223 endif() 224endif() 225 226# set stack reserved size to ~10MB 227if(MSVC) 228 # CMake previously automatically set this value for MSVC builds, but the 229 # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default 230 # value (1 MB) which is not enough for us in tasks such as parsing recursive 231 # C++ templates in Clang. 232 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000") 233elseif(MINGW) # FIXME: Also cygwin? 234 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216") 235endif() 236 237if( MSVC ) 238 if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 ) 239 # For MSVC 2013, disable iterator null pointer checking in debug mode, 240 # especially so std::equal(nullptr, nullptr, nullptr) will not assert. 241 add_llvm_definitions("-D_DEBUG_POINTER_IMPL=") 242 endif() 243 244 include(ChooseMSVCCRT) 245 246 if( MSVC11 ) 247 add_llvm_definitions(-D_VARIADIC_MAX=10) 248 endif() 249 250 # Add definitions that make MSVC much less annoying. 251 add_llvm_definitions( 252 # For some reason MS wants to deprecate a bunch of standard functions... 253 -D_CRT_SECURE_NO_DEPRECATE 254 -D_CRT_SECURE_NO_WARNINGS 255 -D_CRT_NONSTDC_NO_DEPRECATE 256 -D_CRT_NONSTDC_NO_WARNINGS 257 -D_SCL_SECURE_NO_DEPRECATE 258 -D_SCL_SECURE_NO_WARNINGS 259 ) 260 261 # Tell MSVC to use the Unicode version of the Win32 APIs instead of ANSI. 262 add_llvm_definitions( 263 -DUNICODE 264 -D_UNICODE 265 ) 266 267 set(msvc_warning_flags 268 # Disabled warnings. 269 -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline) 270 -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned' 271 -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored' 272 -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data' 273 -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used' 274 -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data' 275 -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception' 276 -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized' 277 -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized' 278 -wd4355 # Suppress ''this' : used in base member initializer list' 279 -wd4456 # Suppress 'declaration of 'var' hides local variable' 280 -wd4457 # Suppress 'declaration of 'var' hides function parameter' 281 -wd4458 # Suppress 'declaration of 'var' hides class member' 282 -wd4459 # Suppress 'declaration of 'var' hides global declaration' 283 -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated' 284 -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible' 285 -wd4722 # Suppress 'function' : destructor never returns, potential memory leak 286 -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)' 287 -wd4100 # Suppress 'unreferenced formal parameter' 288 -wd4127 # Suppress 'conditional expression is constant' 289 -wd4512 # Suppress 'assignment operator could not be generated' 290 -wd4505 # Suppress 'unreferenced local function has been removed' 291 -wd4610 # Suppress '<class> can never be instantiated' 292 -wd4510 # Suppress 'default constructor could not be generated' 293 -wd4702 # Suppress 'unreachable code' 294 -wd4245 # Suppress 'signed/unsigned mismatch' 295 -wd4706 # Suppress 'assignment within conditional expression' 296 -wd4310 # Suppress 'cast truncates constant value' 297 -wd4701 # Suppress 'potentially uninitialized local variable' 298 -wd4703 # Suppress 'potentially uninitialized local pointer variable' 299 -wd4389 # Suppress 'signed/unsigned mismatch' 300 -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable' 301 -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation' 302 -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer' 303 -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed' 304 -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared' 305 # C4592 is disabled because of false positives in Visual Studio 2015 306 # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2. 307 -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation) 308 -wd4319 # Suppress ''operator' : zero extending 'type' to 'type' of greater size' 309 310 # Ideally, we'd like this warning to be enabled, but MSVC 2013 doesn't 311 # support the 'aligned' attribute in the way that clang sources requires (for 312 # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to 313 # avoid unwanted alignment warnings. 314 # When we switch to requiring a version of MSVC that supports the 'alignas' 315 # specifier (MSVC 2015?) this warning can be re-enabled. 316 -wd4324 # Suppress 'structure was padded due to __declspec(align())' 317 318 # Promoted warnings. 319 -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning. 320 321 # Promoted warnings to errors. 322 -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error. 323 ) 324 325 # Enable warnings 326 if (LLVM_ENABLE_WARNINGS) 327 # Put /W4 in front of all the -we flags. cl.exe doesn't care, but for 328 # clang-cl having /W4 after the -we flags will re-enable the warnings 329 # disabled by -we. 330 set(msvc_warning_flags "/W4 ${msvc_warning_flags}") 331 # CMake appends /W3 by default, and having /W3 followed by /W4 will result in 332 # cl : Command line warning D9025 : overriding '/W3' with '/W4'. Since this is 333 # a command line warning and not a compiler warning, it cannot be suppressed except 334 # by fixing the command line. 335 string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}") 336 string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}") 337 338 if (LLVM_ENABLE_PEDANTIC) 339 # No MSVC equivalent available 340 endif (LLVM_ENABLE_PEDANTIC) 341 endif (LLVM_ENABLE_WARNINGS) 342 if (LLVM_ENABLE_WERROR) 343 append("/WX" msvc_warning_flags) 344 endif (LLVM_ENABLE_WERROR) 345 346 foreach(flag ${msvc_warning_flags}) 347 append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 348 endforeach(flag) 349 350 append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 351 352 # /Zc:strictStrings is incompatible with VS12's (Visual Studio 2013's) 353 # debug mode headers. Instead of only enabling them in VS2013's debug mode, 354 # we'll just enable them for Visual Studio 2015 (VS 14, MSVC_VERSION 1900) 355 # and up. 356 if (NOT (MSVC_VERSION LESS 1900)) 357 # Disable string literal const->non-const type conversion. 358 # "When specified, the compiler requires strict const-qualification 359 # conformance for pointers initialized by using string literals." 360 append("/Zc:strictStrings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 361 endif(NOT (MSVC_VERSION LESS 1900)) 362 363 # "Generate Intrinsic Functions". 364 append("/Oi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 365 366 # "Enforce type conversion rules". 367 append("/Zc:rvalueCast" CMAKE_CXX_FLAGS) 368 369 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang") 370 # clang-cl and cl by default produce non-deterministic binaries because 371 # link.exe /incremental requires a timestamp in the .obj file. clang-cl 372 # has the flag /Brepro to force deterministic binaries. We want to pass that 373 # whenever you're building with clang unless you're passing /incremental. 374 # This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag() 375 # because cl.exe does not emit an error on flags it doesn't understand, 376 # letting check_cxx_compiler_flag() claim it understands all flags. 377 check_cxx_compiler_flag("/Brepro" SUPPORTS_BREPRO) 378 if (SUPPORTS_BREPRO) 379 # Check if /INCREMENTAL is passed to the linker and complain that it 380 # won't work with /Brepro. 381 string(TOUPPER "${CMAKE_EXE_LINKER_FLAGS}" upper_exe_flags) 382 string(TOUPPER "${CMAKE_MODULE_LINKER_FLAGS}" upper_module_flags) 383 string(TOUPPER "${CMAKE_SHARED_LINKER_FLAGS}" upper_shared_flags) 384 385 string(FIND "${upper_exe_flags} ${upper_module_flags} ${upper_shared_flags}" 386 "/INCREMENTAL" linker_flag_idx) 387 388 if (${linker_flag_idx} GREATER -1) 389 message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic") 390 else() 391 append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 392 endif() 393 endif() 394 endif() 395 396elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE ) 397 if (LLVM_ENABLE_WARNINGS) 398 append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 399 append("-Wcast-qual" CMAKE_CXX_FLAGS) 400 401 # Turn off missing field initializer warnings for gcc to avoid noise from 402 # false positives with empty {}. Turn them on otherwise (they're off by 403 # default for clang). 404 check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG) 405 if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG) 406 if (CMAKE_COMPILER_IS_GNUCXX) 407 append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 408 else() 409 append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 410 endif() 411 endif() 412 413 append_if(LLVM_ENABLE_PEDANTIC "-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 414 append_if(LLVM_ENABLE_PEDANTIC "-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 415 add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG) 416 append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS) 417 append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS) 418 419 # Check if -Wnon-virtual-dtor warns even though the class is marked final. 420 # If it does, don't add it. So it won't be added on clang 3.4 and older. 421 # This also catches cases when -Wnon-virtual-dtor isn't supported by 422 # the compiler at all. This flag is not activated for gcc since it will 423 # incorrectly identify a protected non-virtual base when there is a friend 424 # declaration. 425 if (NOT CMAKE_COMPILER_IS_GNUCXX) 426 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS}) 427 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11 -Werror=non-virtual-dtor") 428 CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();protected: ~base();}; 429 class derived final : public base { public: ~derived();}; 430 int main() { return 0; }" 431 CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR) 432 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS}) 433 append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR 434 "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS) 435 endif() 436 437 # Enable -Wdelete-non-virtual-dtor if available. 438 add_flag_if_supported("-Wdelete-non-virtual-dtor" DELETE_NON_VIRTUAL_DTOR_FLAG) 439 440 # Check if -Wcomment is OK with an // comment ending with '\' if the next 441 # line is also a // comment. 442 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS}) 443 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment") 444 CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main() {return 0;}" 445 C_WCOMMENT_ALLOWS_LINE_WRAP) 446 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS}) 447 if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP) 448 append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 449 endif() 450 endif (LLVM_ENABLE_WARNINGS) 451 append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 452 add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME) 453 if (LLVM_ENABLE_CXX1Y) 454 check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y) 455 append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS) 456 else() 457 check_cxx_compiler_flag("-std=c++11" CXX_SUPPORTS_CXX11) 458 if (CXX_SUPPORTS_CXX11) 459 if (CYGWIN OR MINGW) 460 # MinGW and Cygwin are a bit stricter and lack things like 461 # 'strdup', 'stricmp', etc in c++11 mode. 462 append("-std=gnu++11" CMAKE_CXX_FLAGS) 463 else() 464 append("-std=c++11" CMAKE_CXX_FLAGS) 465 endif() 466 else() 467 message(FATAL_ERROR "LLVM requires C++11 support but the '-std=c++11' flag isn't supported.") 468 endif() 469 endif() 470 if (LLVM_ENABLE_MODULES) 471 set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS}) 472 set(module_flags "-fmodules -fmodules-cache-path=${PROJECT_BINARY_DIR}/module.cache") 473 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin") 474 # On Darwin -fmodules does not imply -fcxx-modules. 475 set(module_flags "${module_flags} -fcxx-modules") 476 endif() 477 if (LLVM_ENABLE_LOCAL_SUBMODULE_VISIBILITY) 478 set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility") 479 endif() 480 if (LLVM_ENABLE_MODULE_DEBUGGING AND 481 ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR 482 (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO"))) 483 set(module_flags "${module_flags} -gmodules") 484 endif() 485 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${module_flags}") 486 487 # Check that we can build code with modules enabled, and that repeatedly 488 # including <cassert> still manages to respect NDEBUG properly. 489 CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG 490 #include <cassert> 491 #define NDEBUG 492 #include <cassert> 493 int main() { assert(this code is not compiled); }" 494 CXX_SUPPORTS_MODULES) 495 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS}) 496 if (CXX_SUPPORTS_MODULES) 497 append("${module_flags}" CMAKE_CXX_FLAGS) 498 else() 499 message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler") 500 endif() 501 endif(LLVM_ENABLE_MODULES) 502endif( MSVC ) 503 504macro(append_common_sanitizer_flags) 505 if (NOT MSVC) 506 # Append -fno-omit-frame-pointer and turn on debug info to get better 507 # stack traces. 508 add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER) 509 if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND 510 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO") 511 add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY) 512 endif() 513 # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large. 514 if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") 515 add_flag_if_supported("-O1" O1) 516 endif() 517 elseif (CLANG_CL) 518 # Keep frame pointers around. 519 append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 520 if (CMAKE_LINKER MATCHES "lld-link.exe") 521 # Use DWARF debug info with LLD. 522 append("-gdwarf" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 523 else() 524 # Enable codeview otherwise. 525 append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 526 endif() 527 # Always ask the linker to produce symbols with asan. 528 append("-debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 529 endif() 530endmacro() 531 532# Turn on sanitizers if necessary. 533if(LLVM_USE_SANITIZER) 534 if (LLVM_ON_UNIX) 535 if (LLVM_USE_SANITIZER STREQUAL "Address") 536 append_common_sanitizer_flags() 537 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 538 elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?") 539 append_common_sanitizer_flags() 540 append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 541 if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins") 542 append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 543 endif() 544 elseif (LLVM_USE_SANITIZER STREQUAL "Undefined") 545 append_common_sanitizer_flags() 546 append("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all" 547 CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 548 elseif (LLVM_USE_SANITIZER STREQUAL "Thread") 549 append_common_sanitizer_flags() 550 append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 551 elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR 552 LLVM_USE_SANITIZER STREQUAL "Undefined;Address") 553 append_common_sanitizer_flags() 554 append("-fsanitize=address,undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all" 555 CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 556 else() 557 message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}") 558 endif() 559 elseif(MSVC) 560 if (LLVM_USE_SANITIZER STREQUAL "Address") 561 append_common_sanitizer_flags() 562 append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 563 else() 564 message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}") 565 endif() 566 else() 567 message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.") 568 endif() 569 if (LLVM_USE_SANITIZE_COVERAGE) 570 append("-fsanitize-coverage=trace-pc-guard,indirect-calls,trace-cmp" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 571 endif() 572endif() 573 574# Turn on -gsplit-dwarf if requested 575if(LLVM_USE_SPLIT_DWARF) 576 add_definitions("-gsplit-dwarf") 577endif() 578 579add_llvm_definitions( -D__STDC_CONSTANT_MACROS ) 580add_llvm_definitions( -D__STDC_FORMAT_MACROS ) 581add_llvm_definitions( -D__STDC_LIMIT_MACROS ) 582 583# clang doesn't print colored diagnostics when invoked from Ninja 584if (UNIX AND 585 CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND 586 CMAKE_GENERATOR STREQUAL "Ninja") 587 append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) 588endif() 589 590# Add flags for add_dead_strip(). 591# FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF? 592# But MinSizeRel seems to add that automatically, so maybe disable these 593# flags instead if LLVM_NO_DEAD_STRIP is set. 594if(NOT CYGWIN AND NOT WIN32) 595 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND 596 NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") 597 check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS) 598 if (C_SUPPORTS_FNO_FUNCTION_SECTIONS) 599 # Don't add -ffunction-section if it can be disabled with -fno-function-sections. 600 # Doing so will break sanitizers. 601 add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS) 602 endif() 603 add_flag_if_supported("-fdata-sections" FDATA_SECTIONS) 604 endif() 605endif() 606 607if(MSVC) 608 # Remove flags here, for exceptions and RTTI. 609 # Each target property or source property should be responsible to control 610 # them. 611 # CL.EXE complains to override flags like "/GR /GR-". 612 string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}") 613 string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}") 614endif() 615 616# Provide public options to globally control RTTI and EH 617option(LLVM_ENABLE_EH "Enable Exception handling" OFF) 618option(LLVM_ENABLE_RTTI "Enable run time type information" OFF) 619if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI) 620 message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON") 621endif() 622 623option(LLVM_BUILD_INSTRUMENTED "Build LLVM and tools with PGO instrumentation (experimental)" Off) 624mark_as_advanced(LLVM_BUILD_INSTRUMENTED) 625append_if(LLVM_BUILD_INSTRUMENTED "-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}'" 626 CMAKE_CXX_FLAGS 627 CMAKE_C_FLAGS 628 CMAKE_EXE_LINKER_FLAGS 629 CMAKE_SHARED_LINKER_FLAGS) 630 631option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation (experimental)" Off) 632mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE) 633append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate='${LLVM_PROFILE_FILE_PATTERN}' -fcoverage-mapping" 634 CMAKE_CXX_FLAGS 635 CMAKE_C_FLAGS 636 CMAKE_EXE_LINKER_FLAGS 637 CMAKE_SHARED_LINKER_FLAGS) 638 639set(LLVM_ENABLE_LTO OFF CACHE STRING "Build LLVM with LTO. May be specified as Thin or Full to use a particular kind of LTO") 640string(TOUPPER "${LLVM_ENABLE_LTO}" uppercase_LLVM_ENABLE_LTO) 641if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN") 642 append("-flto=thin" CMAKE_CXX_FLAGS CMAKE_C_FLAGS 643 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 644 # On darwin, enable the lto cache. This improves initial build time a little 645 # since we re-link a lot of the same objects, and significantly improves 646 # incremental build time. 647 append_if(APPLE "-Wl,-cache_path_lto,${PROJECT_BINARY_DIR}/lto.cache" 648 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 649elseif(uppercase_LLVM_ENABLE_LTO STREQUAL "FULL") 650 append("-flto=full" CMAKE_CXX_FLAGS CMAKE_C_FLAGS 651 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 652elseif(LLVM_ENABLE_LTO) 653 append("-flto" CMAKE_CXX_FLAGS CMAKE_C_FLAGS 654 CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS) 655endif() 656 657# This option makes utils/extract_symbols.py be used to determine the list of 658# symbols to export from LLVM tools. This is necessary when using MSVC if you 659# want to allow plugins, though note that the plugin has to explicitly link 660# against (exactly one) tool so we can't unilaterally turn on 661# LLVM_ENABLE_PLUGINS when it's enabled. 662option(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS "Export symbols from LLVM tools so that plugins can import them" OFF) 663if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS) 664 message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS") 665endif() 666if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS) 667 message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS") 668endif() 669 670# Plugin support 671# FIXME: Make this configurable. 672if(WIN32 OR CYGWIN) 673 if(BUILD_SHARED_LIBS) 674 set(LLVM_ENABLE_PLUGINS ON) 675 else() 676 set(LLVM_ENABLE_PLUGINS OFF) 677 endif() 678else() 679 set(LLVM_ENABLE_PLUGINS ON) 680endif() 681