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 "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
8
9include(CheckCompilerVersion)
10include(CheckProblematicConfigurations)
11include(HandleLLVMStdlib)
12include(CheckCCompilerFlag)
13include(CheckCSourceCompiles)
14include(CheckCXXCompilerFlag)
15include(CheckCXXSourceCompiles)
16include(CheckSymbolExists)
17include(CMakeDependentOption)
18include(LLVMProcessSources)
19
20if(CMAKE_LINKER MATCHES ".*lld" OR (LLVM_USE_LINKER STREQUAL "lld" OR LLVM_ENABLE_LLD))
21  set(LINKER_IS_LLD TRUE)
22else()
23  set(LINKER_IS_LLD FALSE)
24endif()
25
26if(CMAKE_LINKER MATCHES "lld-link" OR (MSVC AND (LLVM_USE_LINKER STREQUAL "lld" OR LLVM_ENABLE_LLD)))
27  set(LINKER_IS_LLD_LINK TRUE)
28else()
29  set(LINKER_IS_LLD_LINK FALSE)
30endif()
31
32set(LLVM_ENABLE_LTO OFF CACHE STRING "Build LLVM with LTO. May be specified as Thin or Full to use a particular kind of LTO")
33string(TOUPPER "${LLVM_ENABLE_LTO}" uppercase_LLVM_ENABLE_LTO)
34
35# Ninja Job Pool support
36# The following only works with the Ninja generator in CMake >= 3.0.
37set(LLVM_PARALLEL_COMPILE_JOBS "" CACHE STRING
38  "Define the maximum number of concurrent compilation jobs (Ninja only).")
39if(LLVM_RAM_PER_COMPILE_JOB OR LLVM_RAM_PER_LINK_JOB)
40  cmake_host_system_information(RESULT available_physical_memory QUERY AVAILABLE_PHYSICAL_MEMORY)
41  cmake_host_system_information(RESULT number_of_logical_cores QUERY NUMBER_OF_LOGICAL_CORES)
42endif()
43if(LLVM_RAM_PER_COMPILE_JOB)
44  math(EXPR jobs_with_sufficient_memory "${available_physical_memory} / ${LLVM_RAM_PER_COMPILE_JOB}" OUTPUT_FORMAT DECIMAL)
45  if (jobs_with_sufficient_memory LESS 1)
46    set(jobs_with_sufficient_memory 1)
47  endif()
48  if (jobs_with_sufficient_memory LESS number_of_logical_cores)
49    set(LLVM_PARALLEL_COMPILE_JOBS "${jobs_with_sufficient_memory}")
50  else()
51    set(LLVM_PARALLEL_COMPILE_JOBS "${number_of_logical_cores}")
52  endif()
53endif()
54if(LLVM_PARALLEL_COMPILE_JOBS)
55  if(NOT CMAKE_GENERATOR MATCHES "Ninja")
56    message(WARNING "Job pooling is only available with Ninja generators.")
57  else()
58    set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
59    set(CMAKE_JOB_POOL_COMPILE compile_job_pool)
60  endif()
61endif()
62
63set(LLVM_PARALLEL_LINK_JOBS "" CACHE STRING
64  "Define the maximum number of concurrent link jobs (Ninja only).")
65if(LLVM_RAM_PER_LINK_JOB)
66  math(EXPR jobs_with_sufficient_memory "${available_physical_memory} / ${LLVM_RAM_PER_LINK_JOB}" OUTPUT_FORMAT DECIMAL)
67  if (jobs_with_sufficient_memory LESS 1)
68    set(jobs_with_sufficient_memory 1)
69  endif()
70  if (jobs_with_sufficient_memory LESS number_of_logical_cores)
71    set(LLVM_PARALLEL_LINK_JOBS "${jobs_with_sufficient_memory}")
72  else()
73    set(LLVM_PARALLEL_LINK_JOBS "${number_of_logical_cores}")
74  endif()
75endif()
76if(CMAKE_GENERATOR MATCHES "Ninja")
77  if(NOT LLVM_PARALLEL_LINK_JOBS AND uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
78    message(STATUS "ThinLTO provides its own parallel linking - limiting parallel link jobs to 2.")
79    set(LLVM_PARALLEL_LINK_JOBS "2")
80  endif()
81  if(LLVM_PARALLEL_LINK_JOBS)
82    set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
83    set(CMAKE_JOB_POOL_LINK link_job_pool)
84  endif()
85elseif(LLVM_PARALLEL_LINK_JOBS)
86  message(WARNING "Job pooling is only available with Ninja generators.")
87endif()
88
89if( LLVM_ENABLE_ASSERTIONS )
90  # MSVC doesn't like _DEBUG on release builds. See PR 4379.
91  if( NOT MSVC )
92    add_compile_definitions(_DEBUG)
93  endif()
94  # On non-Debug builds cmake automatically defines NDEBUG, so we
95  # explicitly undefine it:
96  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
97    add_compile_options($<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:CXX>>:-UNDEBUG>)
98    if (MSVC)
99      # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
100      foreach (flags_var_to_scrub
101          CMAKE_CXX_FLAGS_RELEASE
102          CMAKE_CXX_FLAGS_RELWITHDEBINFO
103          CMAKE_CXX_FLAGS_MINSIZEREL
104          CMAKE_C_FLAGS_RELEASE
105          CMAKE_C_FLAGS_RELWITHDEBINFO
106          CMAKE_C_FLAGS_MINSIZEREL)
107        string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
108          "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
109      endforeach()
110    endif()
111  endif()
112  # Enable assertions in libstdc++.
113  add_compile_definitions(_GLIBCXX_ASSERTIONS)
114  # Cautiously enable the extensive hardening mode in libc++.
115  if((DEFINED LIBCXX_HARDENING_MODE) AND
116     (NOT LIBCXX_HARDENING_MODE STREQUAL "extensive"))
117    message(WARNING "LLVM_ENABLE_ASSERTIONS implies LIBCXX_HARDENING_MODE \"extensive\" but is overriden from command line with value \"${LIBCXX_HARDENING_MODE}\".")
118  else()
119    set(LIBCXX_HARDENING_MODE "extensive")
120  endif()
121endif()
122
123if(LLVM_ENABLE_EXPENSIVE_CHECKS)
124  add_compile_definitions(EXPENSIVE_CHECKS)
125
126  # In some libstdc++ versions, std::min_element is not constexpr when
127  # _GLIBCXX_DEBUG is enabled.
128  CHECK_CXX_SOURCE_COMPILES("
129    #define _GLIBCXX_DEBUG
130    #include <algorithm>
131    int main(int argc, char** argv) {
132      static constexpr int data[] = {0, 1};
133      constexpr const int* min_elt = std::min_element(&data[0], &data[2]);
134      return 0;
135    }" CXX_SUPPORTS_GLIBCXX_DEBUG)
136  if(CXX_SUPPORTS_GLIBCXX_DEBUG)
137    add_compile_definitions(_GLIBCXX_DEBUG)
138  else()
139    add_compile_definitions(_GLIBCXX_ASSERTIONS)
140  endif()
141endif()
142
143if(LLVM_EXPERIMENTAL_DEBUGINFO_ITERATORS)
144  add_compile_definitions(EXPERIMENTAL_DEBUGINFO_ITERATORS)
145endif()
146
147if (LLVM_ENABLE_STRICT_FIXED_SIZE_VECTORS)
148  add_compile_definitions(STRICT_FIXED_SIZE_VECTORS)
149endif()
150
151string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
152
153if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" )
154  if( LLVM_ENABLE_ASSERTIONS )
155    set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
156  endif()
157elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" )
158  set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
159elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
160  # We don't need to do anything special to turn off ABI breaking checks.
161elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS )
162  # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been
163  # defined.
164else()
165  message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
166endif()
167
168if( LLVM_REVERSE_ITERATION )
169  set( LLVM_ENABLE_REVERSE_ITERATION 1 )
170endif()
171
172if(WIN32)
173  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
174  if(CYGWIN)
175    set(LLVM_ON_WIN32 0)
176    set(LLVM_ON_UNIX 1)
177  else(CYGWIN)
178    set(LLVM_ON_WIN32 1)
179    set(LLVM_ON_UNIX 0)
180  endif(CYGWIN)
181elseif(FUCHSIA OR UNIX)
182  set(LLVM_ON_WIN32 0)
183  set(LLVM_ON_UNIX 1)
184  if(APPLE OR ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
185    set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
186  else()
187    set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
188  endif()
189elseif(CMAKE_SYSTEM_NAME STREQUAL "Generic")
190  set(LLVM_ON_WIN32 0)
191  set(LLVM_ON_UNIX 0)
192  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
193else()
194  MESSAGE(SEND_ERROR "Unable to determine platform")
195endif()
196
197if (CMAKE_SYSTEM_NAME MATCHES "OS390")
198  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
199endif()
200
201set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
202set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
203
204# We use *.dylib rather than *.so on darwin, but we stick with *.so on AIX.
205if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
206  set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_MODULE_SUFFIX})
207else()
208  set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
209endif()
210
211if(APPLE)
212  # Darwin-specific linker flags for loadable modules.
213  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
214endif()
215
216if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
217  # RHEL7 has ar and ranlib being non-deterministic by default. The D flag forces determinism,
218  # however only GNU version of ar and ranlib (2.27) have this option.
219  # RHEL DTS7 is also affected by this, which uses GNU binutils 2.28
220  execute_process(COMMAND ${CMAKE_AR} rD t.a
221                  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
222                  RESULT_VARIABLE AR_RESULT
223                  OUTPUT_QUIET
224                  ERROR_QUIET
225                  )
226  if(${AR_RESULT} EQUAL 0)
227    execute_process(COMMAND ${CMAKE_RANLIB} -D t.a
228                    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
229                    RESULT_VARIABLE RANLIB_RESULT
230                    OUTPUT_QUIET
231                    ERROR_QUIET
232                    )
233    if(${RANLIB_RESULT} EQUAL 0)
234      set(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>"
235          CACHE STRING "archive create command")
236      set(CMAKE_C_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
237      set(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>" CACHE STRING "ranlib command")
238
239      set(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>"
240          CACHE STRING "archive create command")
241      set(CMAKE_CXX_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
242      set(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>" CACHE STRING "ranlib command")
243    endif()
244    file(REMOVE ${CMAKE_BINARY_DIR}/t.a)
245  endif()
246endif()
247
248if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
249  # -fPIC does not enable the large code model for GCC on AIX but does for XL.
250  if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
251    append("-mcmodel=large" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
252    append("-Wl,-bglink=large"
253        CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
254  elseif(CMAKE_CXX_COMPILER_ID MATCHES "XL")
255    # XL generates a small number of relocations not of the large model, -bbigtoc is needed.
256    append("-Wl,-bbigtoc"
257           CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
258    # The default behaviour on AIX processes dynamic initialization of non-local variables with
259    # static storage duration even for archive members that are otherwise unreferenced.
260    # Since `--whole-archive` is not used by the LLVM build to keep such initializations for Linux,
261    # we can limit the processing for archive members to only those that are otherwise referenced.
262    append("-bcdtors:mbr"
263           CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
264  endif()
265  if(BUILD_SHARED_LIBS)
266    # See rpath handling in AddLLVM.cmake
267    # FIXME: Remove this warning if this rpath is no longer hardcoded.
268    message(WARNING "Build and install environment path info may be exposed; binaries will also be unrelocatable.")
269  endif()
270endif()
271
272# Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
273# build might work on ELF but fail on MachO/COFF.
274if(NOT (CMAKE_SYSTEM_NAME MATCHES "Darwin|FreeBSD|OpenBSD|DragonFly|AIX|OS390" OR
275        WIN32 OR CYGWIN) AND
276   NOT LLVM_USE_SANITIZER)
277  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
278endif()
279
280# Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
281# by dlclose(). We need that since the CLI API relies on cross-references
282# between global objects which became horribly broken when one of the libraries
283# is unloaded.
284if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
285  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,nodelete")
286  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-z,nodelete")
287endif()
288
289
290function(append value)
291  foreach(variable ${ARGN})
292    set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
293  endforeach(variable)
294endfunction()
295
296function(append_if condition value)
297  if (${condition})
298    foreach(variable ${ARGN})
299      set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
300    endforeach(variable)
301  endif()
302endfunction()
303
304macro(add_flag_if_supported flag name)
305  check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
306  append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
307  check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
308  append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
309endmacro()
310
311function(add_flag_or_print_warning flag name)
312  check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
313  check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
314  if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
315    message(STATUS "Building with ${flag}")
316    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
317    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
318    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE)
319  else()
320    message(WARNING "${flag} is not supported.")
321  endif()
322endfunction()
323
324function(has_msvc_incremental_no_flag flags incr_no_flag_on)
325  set(${incr_no_flag_on} OFF PARENT_SCOPE)
326  string(FIND "${flags}" "/INCREMENTAL" idx REVERSE)
327  if (${idx} GREATER -1)
328    string(SUBSTRING "${flags}" ${idx} 15 no_flag)
329    if (${no_flag} MATCHES "/INCREMENTAL:NO")
330      set(${incr_no_flag_on} ON PARENT_SCOPE)
331    endif()
332  endif()
333endfunction()
334
335if( LLVM_ENABLE_LLD )
336  if ( LLVM_USE_LINKER )
337    message(FATAL_ERROR "LLVM_ENABLE_LLD and LLVM_USE_LINKER can't be set at the same time")
338  endif()
339
340  # In case of MSVC cmake always invokes the linker directly, so the linker
341  # should be specified by CMAKE_LINKER cmake variable instead of by -fuse-ld
342  # compiler option.
343  if ( MSVC )
344    if(NOT CMAKE_LINKER MATCHES "lld-link")
345      get_filename_component(CXX_COMPILER_DIR ${CMAKE_CXX_COMPILER} DIRECTORY)
346      get_filename_component(C_COMPILER_DIR ${CMAKE_C_COMPILER} DIRECTORY)
347      find_program(LLD_LINK NAMES "lld-link" "lld-link.exe" HINTS ${CXX_COMPILER_DIR} ${C_COMPILER_DIR} DOC "lld linker")
348      if(NOT LLD_LINK)
349        message(FATAL_ERROR
350          "LLVM_ENABLE_LLD set, but cannot find lld-link. "
351          "Consider setting CMAKE_LINKER to lld-link path.")
352      endif()
353      set(CMAKE_LINKER ${LLD_LINK})
354    endif()
355  else()
356    set(LLVM_USE_LINKER "lld")
357  endif()
358endif()
359
360if( LLVM_USE_LINKER )
361  append("-fuse-ld=${LLVM_USE_LINKER}"
362    CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
363  check_cxx_source_compiles("int main() { return 0; }" CXX_SUPPORTS_CUSTOM_LINKER)
364  if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
365    message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'. "
366                        "Please make sure that '${LLVM_USE_LINKER}' is installed and "
367                        "that your host compiler can compile a simple program when "
368                        "given the option '-fuse-ld=${LLVM_USE_LINKER}'.")
369  endif()
370endif()
371
372if( LLVM_ENABLE_PIC )
373  if( XCODE )
374    # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
375    # know how to disable this, so just force ENABLE_PIC off for now.
376    message(WARNING "-fPIC not supported with Xcode.")
377  elseif( WIN32 OR CYGWIN)
378    # On Windows all code is PIC. MinGW warns if -fPIC is used.
379  else()
380    add_flag_or_print_warning("-fPIC" FPIC)
381    # Enable interprocedural optimizations for non-inline functions which would
382    # otherwise be disabled due to GCC -fPIC's default.
383    # Note: GCC<10.3 has a bug on SystemZ.
384    #
385    # Note: Clang allows IPO for -fPIC so this optimization is less effective.
386    # Clang 13 has a bug related to -fsanitize-coverage
387    # -fno-semantic-interposition (https://reviews.llvm.org/D117183).
388    if ((CMAKE_COMPILER_IS_GNUCXX AND
389         NOT (LLVM_NATIVE_ARCH STREQUAL "SystemZ" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.3))
390       OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 14))
391      add_flag_if_supported("-fno-semantic-interposition" FNO_SEMANTIC_INTERPOSITION)
392    endif()
393  endif()
394  # GCC for MIPS can miscompile LLVM due to PR37701.
395  if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
396         NOT Uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
397    add_flag_or_print_warning("-fno-shrink-wrap" FNO_SHRINK_WRAP)
398  endif()
399  # gcc with -O3 -fPIC generates TLS sequences that violate the spec on
400  # Solaris/sparcv9, causing executables created with the system linker
401  # to SEGV (GCC PR target/96607).
402  # clang with -O3 -fPIC generates code that SEGVs.
403  # Both can be worked around by compiling with -O instead.
404  if(${CMAKE_SYSTEM_NAME} STREQUAL "SunOS" AND LLVM_NATIVE_ARCH STREQUAL "Sparc")
405    llvm_replace_compiler_option(CMAKE_CXX_FLAGS_RELEASE "-O[23]" "-O")
406    llvm_replace_compiler_option(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O[23]" "-O")
407  endif()
408endif()
409
410if((NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX")) AND
411   (NOT (WIN32 OR CYGWIN) OR (MINGW AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")))
412  # GCC for MinGW does nothing about -fvisibility-inlines-hidden, but warns
413  # about use of the attributes. As long as we don't use the attributes (to
414  # override the default) we shouldn't set the command line options either.
415  # GCC on AIX warns if -fvisibility-inlines-hidden is used and Clang on AIX doesn't currently support visibility.
416  check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
417  append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
418endif()
419
420if(CMAKE_SIZEOF_VOID_P EQUAL 8 AND MINGW)
421  add_compile_definitions(_FILE_OFFSET_BITS=64)
422endif()
423
424if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
425  # TODO: support other platforms and toolchains.
426  if( LLVM_BUILD_32_BITS )
427    message(STATUS "Building 32 bits executables and libraries.")
428    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
429    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
430    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
431    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
432    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
433
434    # FIXME: CMAKE_SIZEOF_VOID_P is still 8
435    add_compile_definitions(_LARGEFILE_SOURCE)
436    add_compile_definitions(_FILE_OFFSET_BITS=64)
437  endif( LLVM_BUILD_32_BITS )
438endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
439
440# If building on a GNU specific 32-bit system, make sure off_t is 64 bits
441# so that off_t can stored offset > 2GB.
442# Android until version N (API 24) doesn't support it.
443if (ANDROID AND (ANDROID_NATIVE_API_LEVEL LESS 24))
444  set(LLVM_FORCE_SMALLFILE_FOR_ANDROID TRUE)
445endif()
446if( CMAKE_SIZEOF_VOID_P EQUAL 4 AND NOT LLVM_FORCE_SMALLFILE_FOR_ANDROID)
447  # FIXME: It isn't handled in LLVM_BUILD_32_BITS.
448  add_compile_definitions(_LARGEFILE_SOURCE)
449  add_compile_definitions(_FILE_OFFSET_BITS=64)
450endif()
451
452if( XCODE )
453  # For Xcode enable several build settings that correspond to
454  # many warnings that are on by default in Clang but are
455  # not enabled for historical reasons.  For versions of Xcode
456  # that do not support these options they will simply
457  # be ignored.
458  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
459  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
460  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
461  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
462  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
463  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
464  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
465  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
466  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
467  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
468  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
469  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
470  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
471  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
472  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
473endif()
474
475# On Win32 using MS tools, provide an option to set the number of parallel jobs
476# to use.
477if( MSVC_IDE )
478  set(LLVM_COMPILER_JOBS "0" CACHE STRING
479    "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
480  if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
481    if( LLVM_COMPILER_JOBS STREQUAL "0" )
482      add_compile_options(/MP)
483    else()
484      message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
485      add_compile_options(/MP${LLVM_COMPILER_JOBS})
486    endif()
487  else()
488    message(STATUS "Parallel compilation disabled")
489  endif()
490endif()
491
492# set stack reserved size to ~10MB
493if(MSVC)
494  # CMake previously automatically set this value for MSVC builds, but the
495  # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
496  # value (1 MB) which is not enough for us in tasks such as parsing recursive
497  # C++ templates in Clang.
498  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
499elseif(MINGW OR CYGWIN)
500  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
501
502  # Pass -mbig-obj to mingw gas to avoid COFF 2**16 section limit.
503  if (NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
504    append("-Wa,-mbig-obj" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
505  endif()
506endif()
507
508option(LLVM_ENABLE_WARNINGS "Enable compiler warnings." ON)
509
510if( MSVC )
511
512  # Add definitions that make MSVC much less annoying.
513  add_compile_definitions(
514    # For some reason MS wants to deprecate a bunch of standard functions...
515    _CRT_SECURE_NO_DEPRECATE
516    _CRT_SECURE_NO_WARNINGS
517    _CRT_NONSTDC_NO_DEPRECATE
518    _CRT_NONSTDC_NO_WARNINGS
519    _SCL_SECURE_NO_DEPRECATE
520    _SCL_SECURE_NO_WARNINGS
521    )
522
523  # Tell MSVC to use the Unicode version of the Win32 APIs instead of ANSI.
524  add_compile_definitions(
525    UNICODE
526    _UNICODE
527  )
528
529  if (LLVM_WINSYSROOT)
530    if (NOT CLANG_CL)
531      message(ERROR "LLVM_WINSYSROOT requires clang-cl")
532    endif()
533    append("/winsysroot${LLVM_WINSYSROOT}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
534    if (LINKER_IS_LLD_LINK)
535      append("/winsysroot:${LLVM_WINSYSROOT}"
536          CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS
537          CMAKE_SHARED_LINKER_FLAGS)
538    endif()
539  endif()
540
541  if (LLVM_ENABLE_WERROR)
542    append("/WX" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
543  endif (LLVM_ENABLE_WERROR)
544
545  append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
546
547  if (NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
548    # Enable standards-conforming preprocessor.
549    # https://learn.microsoft.com/en-us/cpp/build/reference/zc-preprocessor
550    append("/Zc:preprocessor" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
551  endif ()
552
553  # Some projects use the __cplusplus preprocessor macro to check support for
554  # a particular version of the C++ standard. When this option is not specified
555  # explicitly, macro's value is "199711L" that implies C++98 Standard.
556  # https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
557  append("/Zc:__cplusplus" CMAKE_CXX_FLAGS)
558
559  # Allow users to request PDBs in release mode. CMake offeres the
560  # RelWithDebInfo configuration, but it uses different optimization settings
561  # (/Ob1 vs /Ob2 or -O2 vs -O3). LLVM provides this flag so that users can get
562  # PDBs without changing codegen.
563  option(LLVM_ENABLE_PDB OFF)
564  if (LLVM_ENABLE_PDB AND uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
565    append("/Zi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
566    # /DEBUG disables linker GC and ICF, but we want those in Release mode.
567    append("/DEBUG /OPT:REF /OPT:ICF"
568          CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS
569          CMAKE_SHARED_LINKER_FLAGS)
570  endif()
571
572  # Get all linker flags in upper case form so we can search them.
573  string(CONCAT all_linker_flags_uppercase
574     ${CMAKE_EXE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
575     ${CMAKE_EXE_LINKER_FLAGS} " "
576     ${CMAKE_MODULE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
577     ${CMAKE_MODULE_LINKER_FLAGS} " "
578     ${CMAKE_SHARED_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
579     ${CMAKE_SHARED_LINKER_FLAGS})
580  string(TOUPPER "${all_linker_flags_uppercase}" all_linker_flags_uppercase)
581
582  if (CLANG_CL AND LINKER_IS_LLD)
583    # If we are using clang-cl with lld-link and /debug is present in any of the
584    # linker flag variables, pass -gcodeview-ghash to the compiler to speed up
585    # linking. This flag is orthogonal from /Zi, /Z7, and other flags that
586    # enable debug info emission, and only has an effect if those are also in
587    # use.
588    string(FIND "${all_linker_flags_uppercase}" "/DEBUG" linker_flag_idx)
589    if (${linker_flag_idx} GREATER -1)
590      add_flag_if_supported("-gcodeview-ghash" GCODEVIEW_GHASH)
591    endif()
592  endif()
593
594  # "Generate Intrinsic Functions".
595  append("/Oi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
596
597  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT LLVM_ENABLE_LTO)
598    # clang-cl and cl by default produce non-deterministic binaries because
599    # link.exe /incremental requires a timestamp in the .obj file.  clang-cl
600    # has the flag /Brepro to force deterministic binaries. We want to pass that
601    # whenever you're building with clang unless you're passing /incremental
602    # or using LTO (/Brepro with LTO would result in a warning about the flag
603    # being unused, because we're not generating object files).
604    # This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag()
605    # because cl.exe does not emit an error on flags it doesn't understand,
606    # letting check_cxx_compiler_flag() claim it understands all flags.
607    check_cxx_compiler_flag("/Brepro" SUPPORTS_BREPRO)
608    if (SUPPORTS_BREPRO)
609      # Check if /INCREMENTAL is passed to the linker and complain that it
610      # won't work with /Brepro.
611      has_msvc_incremental_no_flag("${CMAKE_EXE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_EXE_LINKER_FLAGS}" NO_INCR_EXE)
612      has_msvc_incremental_no_flag("${CMAKE_MODULE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_MODULE_LINKER_FLAGS}" NO_INCR_MODULE)
613      has_msvc_incremental_no_flag("${CMAKE_SHARED_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_SHARED_LINKER_FLAGS}" NO_INCR_SHARED)
614      if (NO_INCR_EXE AND NO_INCR_MODULE AND NO_INCR_SHARED)
615        append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
616      else()
617        message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic")
618      endif()
619    endif()
620  endif()
621  # By default MSVC has a 2^16 limit on the number of sections in an object file,
622  # but in many objects files need more than that. This flag is to increase the
623  # number of sections.
624  append("/bigobj" CMAKE_CXX_FLAGS)
625
626  # Enable standards conformance mode.
627  # This ensures handling of various C/C++ constructs is more similar to other compilers.
628  append("/permissive-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
629endif( MSVC )
630
631# Warnings-as-errors handling for GCC-compatible compilers:
632if ( LLVM_COMPILER_IS_GCC_COMPATIBLE )
633  append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
634  append_if(LLVM_ENABLE_WERROR "-Wno-error" CMAKE_REQUIRED_FLAGS)
635endif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
636
637# Specific default warnings-as-errors for compilers accepting GCC-compatible warning flags:
638if ( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
639  add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
640  add_flag_if_supported("-Werror=unguarded-availability-new" WERROR_UNGUARDED_AVAILABILITY_NEW)
641endif( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
642
643if ( LLVM_COMPILER_IS_GCC_COMPATIBLE )
644  # LLVM data structures like llvm::User and llvm::MDNode rely on
645  # the value of object storage persisting beyond the lifetime of the
646  # object (#24952).  This is not standard compliant and causes a runtime
647  # crash if LLVM is built with GCC and LTO enabled (#57740).  Until
648  # these bugs are fixed, we need to disable dead store eliminations
649  # based on object lifetime.
650  add_flag_if_supported("-fno-lifetime-dse" CMAKE_CXX_FLAGS)
651endif ( LLVM_COMPILER_IS_GCC_COMPATIBLE )
652
653# Modules enablement for GCC-compatible compilers:
654if ( LLVM_COMPILER_IS_GCC_COMPATIBLE AND LLVM_ENABLE_MODULES )
655  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
656  set(module_flags "-fmodules -fmodules-cache-path=${PROJECT_BINARY_DIR}/module.cache")
657  if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
658    # On Darwin -fmodules does not imply -fcxx-modules.
659    set(module_flags "${module_flags} -fcxx-modules")
660  endif()
661  if (LLVM_ENABLE_LOCAL_SUBMODULE_VISIBILITY)
662    set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility")
663  endif()
664  if (LLVM_ENABLE_MODULE_DEBUGGING AND
665      ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
666       (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
667    set(module_flags "${module_flags} -gmodules")
668  endif()
669  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${module_flags}")
670
671  # Check that we can build code with modules enabled, and that repeatedly
672  # including <cassert> still manages to respect NDEBUG properly.
673  CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG
674                             #include <cassert>
675                             #define NDEBUG
676                             #include <cassert>
677                             int main() { assert(this code is not compiled); }"
678                             CXX_SUPPORTS_MODULES)
679  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
680  if (CXX_SUPPORTS_MODULES)
681    append("${module_flags}" CMAKE_CXX_FLAGS)
682  else()
683    message(FATAL_ERROR "LLVM_ENABLE_MODULES is not supported by this compiler")
684  endif()
685endif( LLVM_COMPILER_IS_GCC_COMPATIBLE AND LLVM_ENABLE_MODULES )
686
687if (MSVC)
688  if (NOT CLANG_CL)
689    set(msvc_warning_flags
690      # Disabled warnings.
691      -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline)
692      -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
693      -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
694      -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
695      -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
696      -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
697      -wd4456 # Suppress 'declaration of 'var' hides local variable'
698      -wd4457 # Suppress 'declaration of 'var' hides function parameter'
699      -wd4458 # Suppress 'declaration of 'var' hides class member'
700      -wd4459 # Suppress 'declaration of 'var' hides global declaration'
701      -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
702      -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
703      -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
704      -wd4100 # Suppress 'unreferenced formal parameter'
705      -wd4127 # Suppress 'conditional expression is constant'
706      -wd4512 # Suppress 'assignment operator could not be generated'
707      -wd4505 # Suppress 'unreferenced local function has been removed'
708      -wd4610 # Suppress '<class> can never be instantiated'
709      -wd4510 # Suppress 'default constructor could not be generated'
710      -wd4702 # Suppress 'unreachable code'
711      -wd4245 # Suppress ''conversion' : conversion from 'type1' to 'type2', signed/unsigned mismatch'
712      -wd4706 # Suppress 'assignment within conditional expression'
713      -wd4310 # Suppress 'cast truncates constant value'
714      -wd4701 # Suppress 'potentially uninitialized local variable'
715      -wd4703 # Suppress 'potentially uninitialized local pointer variable'
716      -wd4389 # Suppress 'signed/unsigned mismatch'
717      -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable'
718      -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation'
719      -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer'
720      -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed'
721      -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared'
722          # C4592 is disabled because of false positives in Visual Studio 2015
723          # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2.
724      -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation)
725      -wd4319 # Suppress ''operator' : zero extending 'type' to 'type' of greater size'
726          # C4709 is disabled because of a bug with Visual Studio 2017 as of
727          # v15.8.8. Re-evaluate the usefulness of this diagnostic when the bug
728          # is fixed.
729      -wd4709 # Suppress comma operator within array index expression
730
731      # We'd like this warning to be enabled, but it triggers from code in
732      # WinBase.h that we don't have control over.
733      -wd5105 # Suppress macro expansion producing 'defined' has undefined behavior
734
735      # Ideally, we'd like this warning to be enabled, but even MSVC 2019 doesn't
736      # support the 'aligned' attribute in the way that clang sources requires (for
737      # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to
738      # avoid unwanted alignment warnings.
739      -wd4324 # Suppress 'structure was padded due to __declspec(align())'
740
741      # Promoted warnings.
742      -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
743
744      # Promoted warnings to errors.
745      -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
746      )
747  endif(NOT CLANG_CL)
748
749  # Enable warnings
750  if (LLVM_ENABLE_WARNINGS)
751    # Put /W4 in front of all the -we flags. cl.exe doesn't care, but for
752    # clang-cl having /W4 after the -we flags will re-enable the warnings
753    # disabled by -we.
754    set(msvc_warning_flags "/W4 ${msvc_warning_flags}")
755    # CMake appends /W3 by default, and having /W3 followed by /W4 will result in
756    # cl : Command line warning D9025 : overriding '/W3' with '/W4'.  Since this is
757    # a command line warning and not a compiler warning, it cannot be suppressed except
758    # by fixing the command line.
759    string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
760    string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
761
762    if (LLVM_ENABLE_PEDANTIC)
763      # No MSVC equivalent available
764    endif (LLVM_ENABLE_PEDANTIC)
765  endif (LLVM_ENABLE_WARNINGS)
766
767  foreach(flag ${msvc_warning_flags})
768    append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
769  endforeach(flag)
770endif (MSVC)
771
772if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
773
774  # Don't add -Wall for clang-cl, because it maps -Wall to -Weverything for
775  # MSVC compatibility.  /W4 is added above instead.
776  if (NOT CLANG_CL)
777    append("-Wall" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
778  endif()
779
780  append("-Wextra -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
781  append("-Wcast-qual" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
782
783  # Turn off missing field initializer warnings for gcc to avoid noise from
784  # false positives with empty {}. Turn them on otherwise (they're off by
785  # default for clang).
786  check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
787  if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
788    if (CMAKE_COMPILER_IS_GNUCXX)
789      append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
790    else()
791      append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
792    endif()
793  endif()
794
795  if (LLVM_ENABLE_PEDANTIC AND LLVM_COMPILER_IS_GCC_COMPATIBLE)
796    append("-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
797    append("-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
798
799    # GCC warns about redundant toplevel semicolons (enabled by -pedantic
800    # above), while Clang doesn't. Enable the corresponding Clang option to
801    # pick up on these even in builds with Clang.
802    add_flag_if_supported("-Wc++98-compat-extra-semi" CXX98_COMPAT_EXTRA_SEMI_FLAG)
803  endif()
804
805  add_flag_if_supported("-Wimplicit-fallthrough" IMPLICIT_FALLTHROUGH_FLAG)
806  add_flag_if_supported("-Wcovered-switch-default" COVERED_SWITCH_DEFAULT_FLAG)
807  append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
808  append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
809
810  # Disable -Wnonnull for GCC warning as it is emitting a lot of false positives.
811  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
812    append("-Wno-nonnull" CMAKE_CXX_FLAGS)
813  endif()
814
815  # Disable -Wclass-memaccess, a C++-only warning from GCC 8 that fires on
816  # LLVM's ADT classes.
817  check_cxx_compiler_flag("-Wclass-memaccess" CXX_SUPPORTS_CLASS_MEMACCESS_FLAG)
818  append_if(CXX_SUPPORTS_CLASS_MEMACCESS_FLAG "-Wno-class-memaccess" CMAKE_CXX_FLAGS)
819
820  # Disable -Wredundant-move and -Wpessimizing-move on GCC>=9. GCC wants to
821  # remove std::move in code like "A foo(ConvertibleToA a) {
822  # return std::move(a); }", but this code does not compile (or uses the copy
823  # constructor instead) on clang<=3.8. Clang also has a -Wredundant-move and
824  # -Wpessimizing-move, but they only fire when the types match exactly, so we
825  # can keep them here.
826  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
827    check_cxx_compiler_flag("-Wredundant-move" CXX_SUPPORTS_REDUNDANT_MOVE_FLAG)
828    append_if(CXX_SUPPORTS_REDUNDANT_MOVE_FLAG "-Wno-redundant-move" CMAKE_CXX_FLAGS)
829    check_cxx_compiler_flag("-Wpessimizing-move" CXX_SUPPORTS_PESSIMIZING_MOVE_FLAG)
830    append_if(CXX_SUPPORTS_PESSIMIZING_MOVE_FLAG "-Wno-pessimizing-move" CMAKE_CXX_FLAGS)
831  endif()
832
833  # The LLVM libraries have no stable C++ API, so -Wnoexcept-type is not useful.
834  check_cxx_compiler_flag("-Wnoexcept-type" CXX_SUPPORTS_NOEXCEPT_TYPE_FLAG)
835  append_if(CXX_SUPPORTS_NOEXCEPT_TYPE_FLAG "-Wno-noexcept-type" CMAKE_CXX_FLAGS)
836
837  # Check if -Wnon-virtual-dtor warns for a class marked final, when it has a
838  # friend declaration. If it does, don't add -Wnon-virtual-dtor. The case is
839  # considered unhelpful (https://gcc.gnu.org/PR102168).
840  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
841  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=non-virtual-dtor")
842  CHECK_CXX_SOURCE_COMPILES("class f {};
843                             class base {friend f; public: virtual void anchor();protected: ~base();};
844                             int main() { return 0; }"
845                            CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR)
846  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
847  append_if(CXX_WONT_WARN_ON_FINAL_NONVIRTUALDTOR "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
848
849  append("-Wdelete-non-virtual-dtor" CMAKE_CXX_FLAGS)
850
851  # Enable -Wsuggest-override if it's available, and only if it doesn't
852  # suggest adding 'override' to functions that are already marked 'final'
853  # (which means it is disabled for GCC < 9.2).
854  check_cxx_compiler_flag("-Wsuggest-override" CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
855  if (CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
856    set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
857    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=suggest-override")
858    CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();};
859                               class derived : base {public: void anchor() final;};
860                               int main() { return 0; }"
861                              CXX_WSUGGEST_OVERRIDE_ALLOWS_ONLY_FINAL)
862    set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
863    append_if(CXX_WSUGGEST_OVERRIDE_ALLOWS_ONLY_FINAL "-Wsuggest-override" CMAKE_CXX_FLAGS)
864  endif()
865
866  # Check if -Wcomment is OK with an // comment ending with '\' if the next
867  # line is also a // comment.
868  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
869  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
870  CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main(void) {return 0;}"
871                          C_WCOMMENT_ALLOWS_LINE_WRAP)
872  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
873  if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
874    append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
875  endif()
876
877  # Enable -Wstring-conversion to catch misuse of string literals.
878  add_flag_if_supported("-Wstring-conversion" STRING_CONVERSION_FLAG)
879
880  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
881    # Disable the misleading indentation warning with GCC; GCC can
882    # produce noisy notes about this getting disabled in large files.
883    # See e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89549
884    check_cxx_compiler_flag("-Wmisleading-indentation" CXX_SUPPORTS_MISLEADING_INDENTATION_FLAG)
885    append_if(CXX_SUPPORTS_MISLEADING_INDENTATION_FLAG "-Wno-misleading-indentation" CMAKE_CXX_FLAGS)
886  else()
887    # Prevent bugs that can happen with llvm's brace style.
888    add_flag_if_supported("-Wmisleading-indentation" MISLEADING_INDENTATION_FLAG)
889  endif()
890
891  # Enable -Wctad-maybe-unsupported to catch unintended use of CTAD.
892  add_flag_if_supported("-Wctad-maybe-unsupported" CTAD_MAYBE_UNSPPORTED_FLAG)
893endif (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
894
895if (LLVM_COMPILER_IS_GCC_COMPATIBLE AND NOT LLVM_ENABLE_WARNINGS)
896  append("-w" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
897endif()
898
899macro(append_common_sanitizer_flags)
900  if (NOT MSVC OR CLANG_CL)
901    # Append -fno-omit-frame-pointer and turn on debug info to get better
902    # stack traces.
903    add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
904    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
905        NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
906      add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
907    endif()
908    # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
909    if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND LLVM_OPTIMIZE_SANITIZED_BUILDS)
910      add_flag_if_supported("-O1" O1)
911    endif()
912  else()
913    # Always ask the linker to produce symbols with asan.
914    append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
915    append("/debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
916    # Not compatible with /INCREMENTAL link.
917    foreach (flags_opt_to_scrub
918        CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
919      string (REGEX REPLACE "(^| )/INCREMENTAL($| )" " /INCREMENTAL:NO "
920        "${flags_opt_to_scrub}" "${${flags_opt_to_scrub}}")
921    endforeach()
922    if (LLVM_HOST_TRIPLE MATCHES "i[2-6]86-.*")
923      # Keep frame pointers around.
924      append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
925    endif()
926  endif()
927endmacro()
928
929# Turn on sanitizers if necessary.
930if(LLVM_USE_SANITIZER)
931  if (LLVM_ON_UNIX)
932    if (LLVM_USE_SANITIZER STREQUAL "Address")
933      append_common_sanitizer_flags()
934      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
935    elseif (LLVM_USE_SANITIZER STREQUAL "HWAddress")
936      append_common_sanitizer_flags()
937      append("-fsanitize=hwaddress" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
938    elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
939      append_common_sanitizer_flags()
940      append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
941      if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
942        append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
943      endif()
944    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
945      append_common_sanitizer_flags()
946      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
947    elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
948      append_common_sanitizer_flags()
949      append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
950    elseif (LLVM_USE_SANITIZER STREQUAL "DataFlow")
951      append("-fsanitize=dataflow" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
952    elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
953            LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
954      append_common_sanitizer_flags()
955      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
956      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
957    elseif (LLVM_USE_SANITIZER STREQUAL "Leaks")
958      append_common_sanitizer_flags()
959      append("-fsanitize=leak" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
960    else()
961      message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
962    endif()
963  elseif(MINGW)
964    if (LLVM_USE_SANITIZER STREQUAL "Address")
965      append_common_sanitizer_flags()
966      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
967    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
968      append_common_sanitizer_flags()
969      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
970    elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
971            LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
972      append_common_sanitizer_flags()
973      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
974      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
975    else()
976      message(FATAL_ERROR "This sanitizer not yet supported in a MinGW environment: ${LLVM_USE_SANITIZER}")
977    endif()
978  elseif(MSVC)
979    if (NOT LLVM_USE_SANITIZER MATCHES "^(Address|Undefined|Address;Undefined|Undefined;Address)$")
980      message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}")
981    endif()
982    append_common_sanitizer_flags()
983    if (LINKER_IS_LLD_LINK)
984      if (LLVM_HOST_TRIPLE MATCHES "i[2-6]86-.*")
985        set(arch "i386")
986      else()
987        set(arch "x86_64")
988      endif()
989      # Prepare ASAN runtime if needed
990      if (LLVM_USE_SANITIZER MATCHES ".*Address.*")
991        # lld string tail merging interacts badly with ASAN on Windows, turn it off here
992        # See https://github.com/llvm/llvm-project/issues/62078
993        append("/opt:nolldtailmerge" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
994        if (${CMAKE_MSVC_RUNTIME_LIBRARY} MATCHES "^(MultiThreaded|MultiThreadedDebug)$")
995          append("/wholearchive:clang_rt.asan-${arch}.lib /wholearchive:clang_rt.asan_cxx-${arch}.lib"
996            CMAKE_EXE_LINKER_FLAGS)
997          append("/wholearchive:clang_rt.asan_dll_thunk-${arch}.lib"
998            CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
999        else()
1000          append("clang_rt.asan_dynamic-${arch}.lib /wholearchive:clang_rt.asan_dynamic_runtime_thunk-${arch}.lib"
1001            CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1002        endif()
1003      endif()
1004    endif()
1005    if (LLVM_USE_SANITIZER MATCHES ".*Address.*")
1006      if (NOT CLANG_CL)
1007        append("/fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1008        # Not compatible with /RTC flags.
1009        foreach (flags_opt_to_scrub
1010            CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE} CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE})
1011          string (REGEX REPLACE "(^| )/RTC[1csu]*($| )" " "
1012            "${flags_opt_to_scrub}" "${${flags_opt_to_scrub}}")
1013        endforeach()
1014      else()
1015        append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1016      endif()
1017    endif()
1018    if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
1019      if (NOT CLANG_CL)
1020        message(FATAL_ERROR "This sanitizer is only supported by clang-cl: Undefined")
1021      endif()
1022      append(${LLVM_UBSAN_FLAGS} CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1023    endif()
1024  else()
1025    message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.")
1026  endif()
1027  if (LLVM_USE_SANITIZE_COVERAGE)
1028    append("-fsanitize=fuzzer-no-link" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1029  endif()
1030  if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
1031    set(IGNORELIST_FILE "${PROJECT_SOURCE_DIR}/utils/sanitizers/ubsan_ignorelist.txt")
1032    if (EXISTS "${IGNORELIST_FILE}")
1033      # Use this option name version since -fsanitize-ignorelist is only
1034      # accepted with clang 13.0 or newer.
1035      append("-fsanitize-blacklist=${IGNORELIST_FILE}"
1036             CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1037    endif()
1038  endif()
1039endif()
1040
1041# Turn on -gsplit-dwarf if requested in debug builds.
1042if (LLVM_USE_SPLIT_DWARF AND
1043    ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
1044     (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
1045  # Limit to clang and gcc so far. Add compilers supporting this option.
1046  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
1047      CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
1048    add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-gsplit-dwarf>)
1049    include(LLVMCheckLinkerFlag)
1050    llvm_check_linker_flag(CXX "-Wl,--gdb-index" LINKER_SUPPORTS_GDB_INDEX)
1051    append_if(LINKER_SUPPORTS_GDB_INDEX "-Wl,--gdb-index"
1052      CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1053  endif()
1054endif()
1055
1056add_compile_definitions(__STDC_CONSTANT_MACROS)
1057add_compile_definitions(__STDC_FORMAT_MACROS)
1058add_compile_definitions(__STDC_LIMIT_MACROS)
1059
1060# clang and gcc don't default-print colored diagnostics when invoked from Ninja.
1061if (UNIX AND
1062    CMAKE_GENERATOR MATCHES "Ninja" AND
1063    (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
1064     (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND
1065      NOT (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9))))
1066  append("-fdiagnostics-color" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1067endif()
1068
1069# lld doesn't print colored diagnostics when invoked from Ninja
1070if (UNIX AND CMAKE_GENERATOR MATCHES "Ninja")
1071  include(LLVMCheckLinkerFlag)
1072  llvm_check_linker_flag(CXX "-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
1073  append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,--color-diagnostics"
1074    CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1075endif()
1076
1077# Add flags for add_dead_strip().
1078# FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
1079# But MinSizeRel seems to add that automatically, so maybe disable these
1080# flags instead if LLVM_NO_DEAD_STRIP is set.
1081if(NOT CYGWIN AND NOT MSVC)
1082  if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
1083     NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
1084    check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
1085    if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
1086      # Don't add -ffunction-sections if it can't be disabled with -fno-function-sections.
1087      # Doing so will break sanitizers.
1088      add_flag_if_supported("-ffunction-sections" FFUNCTION_SECTIONS)
1089    elseif (CMAKE_CXX_COMPILER_ID MATCHES "XL")
1090      append("-qfuncsect" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1091    endif()
1092    add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
1093  endif()
1094elseif(MSVC)
1095  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
1096    append("/Gw" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1097  endif()
1098endif()
1099
1100if(MSVC)
1101  # Remove flags here, for exceptions and RTTI.
1102  # Each target property or source property should be responsible to control
1103  # them.
1104  # CL.EXE complains to override flags like "/GR /GR-".
1105  string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
1106  string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
1107endif()
1108
1109# Provide public options to globally control RTTI and EH
1110option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
1111option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
1112if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
1113  message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
1114endif()
1115
1116option(LLVM_ENABLE_IR_PGO "Build LLVM and tools with IR PGO instrumentation (deprecated)" Off)
1117mark_as_advanced(LLVM_ENABLE_IR_PGO)
1118
1119set(LLVM_BUILD_INSTRUMENTED OFF CACHE STRING "Build LLVM and tools with PGO instrumentation. May be specified as IR or Frontend")
1120set(LLVM_VP_COUNTERS_PER_SITE "1.5" CACHE STRING "Value profile counters to use per site for IR PGO with Clang")
1121mark_as_advanced(LLVM_BUILD_INSTRUMENTED LLVM_VP_COUNTERS_PER_SITE)
1122string(TOUPPER "${LLVM_BUILD_INSTRUMENTED}" uppercase_LLVM_BUILD_INSTRUMENTED)
1123
1124if (LLVM_BUILD_INSTRUMENTED)
1125  if (LLVM_ENABLE_IR_PGO OR uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "IR")
1126    append("-fprofile-generate=\"${LLVM_PROFILE_DATA_DIR}\""
1127      CMAKE_CXX_FLAGS
1128      CMAKE_C_FLAGS)
1129    if(NOT LINKER_IS_LLD_LINK)
1130      append("-fprofile-generate=\"${LLVM_PROFILE_DATA_DIR}\""
1131        CMAKE_EXE_LINKER_FLAGS
1132        CMAKE_SHARED_LINKER_FLAGS)
1133    endif()
1134    # Set this to avoid running out of the value profile node section
1135    # under clang in dynamic linking mode.
1136    if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
1137        CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 11 AND
1138        LLVM_LINK_LLVM_DYLIB)
1139      append("-Xclang -mllvm -Xclang -vp-counters-per-site=${LLVM_VP_COUNTERS_PER_SITE}"
1140        CMAKE_CXX_FLAGS
1141        CMAKE_C_FLAGS)
1142    endif()
1143  elseif(uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "CSIR")
1144    append("-fcs-profile-generate=\"${LLVM_CSPROFILE_DATA_DIR}\""
1145      CMAKE_CXX_FLAGS
1146      CMAKE_C_FLAGS)
1147    if(NOT LINKER_IS_LLD_LINK)
1148      append("-fcs-profile-generate=\"${LLVM_CSPROFILE_DATA_DIR}\""
1149        CMAKE_EXE_LINKER_FLAGS
1150        CMAKE_SHARED_LINKER_FLAGS)
1151    endif()
1152  else()
1153    append("-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\""
1154      CMAKE_CXX_FLAGS
1155      CMAKE_C_FLAGS)
1156    if(NOT LINKER_IS_LLD_LINK)
1157      append("-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\""
1158        CMAKE_EXE_LINKER_FLAGS
1159        CMAKE_SHARED_LINKER_FLAGS)
1160    endif()
1161  endif()
1162endif()
1163
1164# When using clang-cl with an instrumentation-based tool, add clang's library
1165# resource directory to the library search path. Because cmake invokes the
1166# linker directly, it isn't sufficient to pass -fsanitize=* to the linker.
1167if (CLANG_CL AND (LLVM_BUILD_INSTRUMENTED OR LLVM_USE_SANITIZER))
1168  execute_process(
1169    COMMAND ${CMAKE_CXX_COMPILER} /clang:-print-libgcc-file-name /clang:--rtlib=compiler-rt
1170    OUTPUT_VARIABLE clang_compiler_rt_file
1171    ERROR_VARIABLE clang_cl_stderr
1172    OUTPUT_STRIP_TRAILING_WHITESPACE
1173    ERROR_STRIP_TRAILING_WHITESPACE
1174    RESULT_VARIABLE clang_cl_exit_code)
1175  if (NOT "${clang_cl_exit_code}" STREQUAL "0")
1176    message(FATAL_ERROR
1177      "Unable to invoke clang-cl to find resource dir: ${clang_cl_stderr}")
1178  endif()
1179  file(TO_CMAKE_PATH "${clang_compiler_rt_file}" clang_compiler_rt_file)
1180  get_filename_component(clang_runtime_dir "${clang_compiler_rt_file}" DIRECTORY)
1181  append("/libpath:\"${clang_runtime_dir}\""
1182    CMAKE_EXE_LINKER_FLAGS
1183    CMAKE_MODULE_LINKER_FLAGS
1184    CMAKE_SHARED_LINKER_FLAGS)
1185endif()
1186
1187if(LLVM_PROFDATA_FILE AND EXISTS ${LLVM_PROFDATA_FILE})
1188  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
1189    append("-fprofile-instr-use=\"${LLVM_PROFDATA_FILE}\""
1190      CMAKE_CXX_FLAGS
1191      CMAKE_C_FLAGS)
1192    if(NOT LINKER_IS_LLD_LINK)
1193      append("-fprofile-instr-use=\"${LLVM_PROFDATA_FILE}\""
1194        CMAKE_EXE_LINKER_FLAGS
1195        CMAKE_SHARED_LINKER_FLAGS)
1196    endif()
1197  else()
1198    message(FATAL_ERROR "LLVM_PROFDATA_FILE can only be specified when compiling with clang")
1199  endif()
1200endif()
1201
1202option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation" Off)
1203option(LLVM_INDIVIDUAL_TEST_COVERAGE "Emit individual coverage file for each test case." OFF)
1204mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE)
1205append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\" -fcoverage-mapping"
1206  CMAKE_CXX_FLAGS
1207  CMAKE_C_FLAGS
1208  CMAKE_EXE_LINKER_FLAGS
1209  CMAKE_SHARED_LINKER_FLAGS)
1210
1211if (LLVM_BUILD_INSTRUMENTED AND LLVM_BUILD_INSTRUMENTED_COVERAGE)
1212  message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
1213endif()
1214
1215set(LLVM_THINLTO_CACHE_PATH "${PROJECT_BINARY_DIR}/lto.cache" CACHE STRING "Set ThinLTO cache path. This can be used when building LLVM from several different directiories.")
1216
1217if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK AND NOT MINGW)
1218  message(FATAL_ERROR "When compiling for Windows, LLVM_ENABLE_LTO requires using lld as the linker (point CMAKE_LINKER at lld-link.exe)")
1219endif()
1220if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
1221  append("-flto=thin" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1222  if(NOT LINKER_IS_LLD_LINK)
1223    append("-flto=thin" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1224  endif()
1225  # If the linker supports it, enable the lto cache. This improves initial build
1226  # time a little since we re-link a lot of the same objects, and significantly
1227  # improves incremental build time.
1228  # FIXME: We should move all this logic into the clang driver.
1229  if(APPLE)
1230    append("-Wl,-cache_path_lto,${LLVM_THINLTO_CACHE_PATH}"
1231           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1232  elseif((UNIX OR MINGW) AND LLVM_USE_LINKER STREQUAL "lld")
1233    append("-Wl,--thinlto-cache-dir=${LLVM_THINLTO_CACHE_PATH}"
1234           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1235  elseif(LLVM_USE_LINKER STREQUAL "gold")
1236    append("-Wl,--plugin-opt,cache-dir=${LLVM_THINLTO_CACHE_PATH}"
1237           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1238  elseif(LINKER_IS_LLD_LINK)
1239    append("/lldltocache:${LLVM_THINLTO_CACHE_PATH}"
1240           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1241  endif()
1242elseif(uppercase_LLVM_ENABLE_LTO STREQUAL "FULL")
1243  append("-flto=full" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1244  if(NOT LINKER_IS_LLD_LINK)
1245    append("-flto=full" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1246  endif()
1247elseif(LLVM_ENABLE_LTO)
1248  append("-flto" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1249  if(NOT LINKER_IS_LLD_LINK)
1250    append("-flto" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1251  endif()
1252endif()
1253
1254# Set an AIX default for LLVM_EXPORT_SYMBOLS_FOR_PLUGINS based on whether we are
1255# doing dynamic linking (see below).
1256set(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default OFF)
1257if (NOT (BUILD_SHARED_LIBS OR LLVM_LINK_LLVM_DYLIB))
1258  set(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default ON)
1259endif()
1260
1261# This option makes utils/extract_symbols.py be used to determine the list of
1262# symbols to export from LLVM tools. This is necessary when on AIX or when using
1263# MSVC if you want to allow plugins. On AIX we don't show this option, and we
1264# enable it by default except when the LLVM libraries are set up for dynamic
1265# linking (due to incompatibility). With MSVC, note that the plugin has to
1266# explicitly link against (exactly one) tool so we can't unilaterally turn on
1267# LLVM_ENABLE_PLUGINS when it's enabled.
1268CMAKE_DEPENDENT_OPTION(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS
1269       "Export symbols from LLVM tools so that plugins can import them" OFF
1270       "NOT ${CMAKE_SYSTEM_NAME} MATCHES AIX" ${LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default})
1271if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
1272  message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
1273endif()
1274if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
1275  message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
1276endif()
1277
1278# By default we should enable LLVM_ENABLE_IDE only for multi-configuration
1279# generators. This option disables optional build system features that make IDEs
1280# less usable.
1281set(LLVM_ENABLE_IDE_default OFF)
1282if (CMAKE_CONFIGURATION_TYPES)
1283  set(LLVM_ENABLE_IDE_default ON)
1284endif()
1285option(LLVM_ENABLE_IDE
1286       "Disable optional build system features that cause problems for IDE generators"
1287       ${LLVM_ENABLE_IDE_default})
1288if (CMAKE_CONFIGURATION_TYPES AND NOT LLVM_ENABLE_IDE)
1289  message(WARNING "Disabling LLVM_ENABLE_IDE on multi-configuration generators is not recommended.")
1290endif()
1291
1292function(get_compile_definitions)
1293  get_directory_property(top_dir_definitions DIRECTORY ${CMAKE_SOURCE_DIR} COMPILE_DEFINITIONS)
1294  foreach(definition ${top_dir_definitions})
1295    if(DEFINED result)
1296      string(APPEND result " -D${definition}")
1297    else()
1298      set(result "-D${definition}")
1299    endif()
1300  endforeach()
1301  set(LLVM_DEFINITIONS "${result}" PARENT_SCOPE)
1302endfunction()
1303get_compile_definitions()
1304
1305option(LLVM_FORCE_ENABLE_STATS "Enable statistics collection for builds that wouldn't normally enable it" OFF)
1306
1307check_symbol_exists(os_signpost_interval_begin "os/signpost.h" macos_signposts_available)
1308if(macos_signposts_available)
1309  check_cxx_source_compiles(
1310    "#include <os/signpost.h>
1311    int main() { os_signpost_interval_begin(nullptr, 0, \"\", \"\"); return 0; }"
1312    macos_signposts_usable)
1313  if(macos_signposts_usable)
1314    set(LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS "WITH_ASSERTS" CACHE STRING
1315        "Enable support for Xcode signposts. Can be WITH_ASSERTS, FORCE_ON, FORCE_OFF")
1316    string(TOUPPER "${LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS}"
1317                   uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS)
1318    if( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "WITH_ASSERTS" )
1319      if( LLVM_ENABLE_ASSERTIONS )
1320        set( LLVM_SUPPORT_XCODE_SIGNPOSTS 1 )
1321      endif()
1322    elseif( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "FORCE_ON" )
1323      set( LLVM_SUPPORT_XCODE_SIGNPOSTS 1 )
1324    elseif( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "FORCE_OFF" )
1325      # We don't need to do anything special to turn off signposts.
1326    elseif( NOT DEFINED LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS )
1327      # Treat LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS like "FORCE_OFF" when it has not been
1328      # defined.
1329    else()
1330      message(FATAL_ERROR "Unknown value for LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS:"
1331                          " \"${LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS}\"!")
1332    endif()
1333  endif()
1334endif()
1335
1336set(LLVM_SOURCE_PREFIX "" CACHE STRING "Use prefix for sources")
1337
1338option(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO "Use relative paths in debug info" OFF)
1339
1340if(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO)
1341  check_c_compiler_flag("-fdebug-prefix-map=foo=bar" SUPPORTS_FDEBUG_PREFIX_MAP)
1342  if(LLVM_ENABLE_PROJECTS_USED)
1343    get_filename_component(source_root "${LLVM_MAIN_SRC_DIR}/.." ABSOLUTE)
1344  else()
1345    set(source_root "${LLVM_MAIN_SRC_DIR}")
1346  endif()
1347  file(RELATIVE_PATH relative_root "${CMAKE_BINARY_DIR}" "${source_root}")
1348  append_if(SUPPORTS_FDEBUG_PREFIX_MAP "-fdebug-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1349  append_if(SUPPORTS_FDEBUG_PREFIX_MAP "-fdebug-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1350  add_flag_if_supported("-no-canonical-prefixes" NO_CANONICAL_PREFIXES)
1351endif()
1352
1353option(LLVM_USE_RELATIVE_PATHS_IN_FILES "Use relative paths in sources and debug info" OFF)
1354
1355if(LLVM_USE_RELATIVE_PATHS_IN_FILES)
1356  check_c_compiler_flag("-ffile-prefix-map=foo=bar" SUPPORTS_FFILE_PREFIX_MAP)
1357  if(LLVM_ENABLE_PROJECTS_USED)
1358    get_filename_component(source_root "${LLVM_MAIN_SRC_DIR}/.." ABSOLUTE)
1359  else()
1360    set(source_root "${LLVM_MAIN_SRC_DIR}")
1361  endif()
1362  file(RELATIVE_PATH relative_root "${CMAKE_BINARY_DIR}" "${source_root}")
1363  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1364  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1365  add_flag_if_supported("-no-canonical-prefixes" NO_CANONICAL_PREFIXES)
1366endif()
1367
1368set(LLVM_THIRD_PARTY_DIR  ${CMAKE_CURRENT_SOURCE_DIR}/../third-party CACHE STRING
1369    "Directory containing third party software used by LLVM (e.g. googletest)")
1370
1371set(LLVM_UNITTEST_LINK_FLAGS "" CACHE STRING
1372    "Additional linker flags for unit tests")
1373
1374if(LLVM_ENABLE_LLVM_LIBC)
1375  check_library_exists(llvmlibc printf "" HAVE_LLVM_LIBC)
1376  if(NOT HAVE_LLVM_LIBC)
1377    message(WARNING "Unable to link against LLVM libc. LLVM will be built without linking against the LLVM libc overlay.")
1378  endif()
1379endif()
1380