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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
35option(LLVM_ENABLE_FATLTO "Build LLVM with -ffat-lto-objects." OFF)
36
37# Ninja Job Pool support
38# The following only works with the Ninja generator in CMake >= 3.0.
39set(LLVM_PARALLEL_COMPILE_JOBS "" CACHE STRING
40  "Define the maximum number of concurrent compilation jobs (Ninja only).")
41if(LLVM_RAM_PER_COMPILE_JOB OR LLVM_RAM_PER_LINK_JOB OR LLVM_RAM_PER_TABLEGEN_JOB)
42  cmake_host_system_information(RESULT available_physical_memory QUERY AVAILABLE_PHYSICAL_MEMORY)
43  cmake_host_system_information(RESULT number_of_logical_cores QUERY NUMBER_OF_LOGICAL_CORES)
44endif()
45if(LLVM_RAM_PER_COMPILE_JOB)
46  math(EXPR jobs_with_sufficient_memory "${available_physical_memory} / ${LLVM_RAM_PER_COMPILE_JOB}" OUTPUT_FORMAT DECIMAL)
47  if (jobs_with_sufficient_memory LESS 1)
48    set(jobs_with_sufficient_memory 1)
49  endif()
50  if (jobs_with_sufficient_memory LESS number_of_logical_cores)
51    set(LLVM_PARALLEL_COMPILE_JOBS "${jobs_with_sufficient_memory}")
52  else()
53    set(LLVM_PARALLEL_COMPILE_JOBS "${number_of_logical_cores}")
54  endif()
55endif()
56if(LLVM_PARALLEL_COMPILE_JOBS)
57  if(NOT CMAKE_GENERATOR MATCHES "Ninja")
58    message(WARNING "Job pooling is only available with Ninja generators.")
59  else()
60    set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
61    set(CMAKE_JOB_POOL_COMPILE compile_job_pool)
62  endif()
63endif()
64
65set(LLVM_PARALLEL_LINK_JOBS "" CACHE STRING
66  "Define the maximum number of concurrent link jobs (Ninja only).")
67if(LLVM_RAM_PER_LINK_JOB)
68  math(EXPR jobs_with_sufficient_memory "${available_physical_memory} / ${LLVM_RAM_PER_LINK_JOB}" OUTPUT_FORMAT DECIMAL)
69  if (jobs_with_sufficient_memory LESS 1)
70    set(jobs_with_sufficient_memory 1)
71  endif()
72  if (jobs_with_sufficient_memory LESS number_of_logical_cores)
73    set(LLVM_PARALLEL_LINK_JOBS "${jobs_with_sufficient_memory}")
74  else()
75    set(LLVM_PARALLEL_LINK_JOBS "${number_of_logical_cores}")
76  endif()
77endif()
78if(CMAKE_GENERATOR MATCHES "Ninja")
79  if(NOT LLVM_PARALLEL_LINK_JOBS AND uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
80    message(STATUS "ThinLTO provides its own parallel linking - limiting parallel link jobs to 2.")
81    set(LLVM_PARALLEL_LINK_JOBS "2")
82  endif()
83  if(LLVM_PARALLEL_LINK_JOBS)
84    set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
85    set(CMAKE_JOB_POOL_LINK link_job_pool)
86  endif()
87elseif(LLVM_PARALLEL_LINK_JOBS)
88  message(WARNING "Job pooling is only available with Ninja generators.")
89endif()
90
91set(LLVM_PARALLEL_TABLEGEN_JOBS "" CACHE STRING
92  "Define the maximum number of concurrent tablegen jobs (Ninja only).")
93if(LLVM_RAM_PER_TABLEGEN_JOB)
94  math(EXPR jobs_with_sufficient_memory "${available_physical_memory} / ${LLVM_RAM_PER_TABLEGEN_JOB}" OUTPUT_FORMAT DECIMAL)
95  if (jobs_with_sufficient_memory LESS 1)
96    set(jobs_with_sufficient_memory 1)
97  endif()
98  if (jobs_with_sufficient_memory LESS number_of_logical_cores)
99    set(LLVM_PARALLEL_TABLEGEN_JOBS "${jobs_with_sufficient_memory}")
100  else()
101    set(LLVM_PARALLEL_TABLEGEN_JOBS "${number_of_logical_cores}")
102  endif()
103endif()
104if(LLVM_PARALLEL_TABLEGEN_JOBS)
105  if(NOT CMAKE_GENERATOR MATCHES "Ninja")
106    message(WARNING "Job pooling is only available with Ninja generators.")
107  else()
108    set_property(GLOBAL APPEND PROPERTY JOB_POOLS tablegen_job_pool=${LLVM_PARALLEL_TABLEGEN_JOBS})
109    # Job pool for tablegen is set on the add_custom_command
110  endif()
111endif()
112
113if( LLVM_ENABLE_ASSERTIONS )
114  # MSVC doesn't like _DEBUG on release builds. See PR 4379.
115  if( NOT MSVC )
116    add_compile_definitions(_DEBUG)
117  endif()
118  # On non-Debug builds cmake automatically defines NDEBUG, so we
119  # explicitly undefine it:
120  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
121    add_compile_options($<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:CXX>>:-UNDEBUG>)
122    if (MSVC)
123      # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
124      foreach (flags_var_to_scrub
125          CMAKE_CXX_FLAGS_RELEASE
126          CMAKE_CXX_FLAGS_RELWITHDEBINFO
127          CMAKE_CXX_FLAGS_MINSIZEREL
128          CMAKE_C_FLAGS_RELEASE
129          CMAKE_C_FLAGS_RELWITHDEBINFO
130          CMAKE_C_FLAGS_MINSIZEREL)
131        string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
132          "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
133      endforeach()
134    endif()
135  endif()
136  # Enable assertions in libstdc++.
137  add_compile_definitions(_GLIBCXX_ASSERTIONS)
138  # Cautiously enable the extensive hardening mode in libc++.
139  if((DEFINED LIBCXX_HARDENING_MODE) AND
140     (NOT LIBCXX_HARDENING_MODE STREQUAL "extensive"))
141    message(WARNING "LLVM_ENABLE_ASSERTIONS implies LIBCXX_HARDENING_MODE \"extensive\" but is overriden from command line with value \"${LIBCXX_HARDENING_MODE}\".")
142  else()
143    set(LIBCXX_HARDENING_MODE "extensive")
144  endif()
145endif()
146
147# If we are targeting a GPU architecture in a runtimes build we want to ignore
148# all the standard flag handling.
149if(LLVM_RUNTIMES_GPU_BUILD)
150  return()
151endif()
152
153if(LLVM_ENABLE_EXPENSIVE_CHECKS)
154  # When LLVM_ENABLE_EXPENSIVE_CHECKS is ON, LLVM will intercept errors
155  # using assert(). An explicit check is performed here.
156  if (NOT LLVM_ENABLE_ASSERTIONS)
157    message(FATAL_ERROR "LLVM_ENABLE_EXPENSIVE_CHECKS requires LLVM_ENABLE_ASSERTIONS \"ON\".")
158  endif()
159  add_compile_definitions(EXPENSIVE_CHECKS)
160
161  # In libstdc++ 9 and earlier, std::min_element is not constexpr when
162  # _GLIBCXX_DEBUG is enabled.
163  CHECK_CXX_SOURCE_COMPILES("
164    #define _GLIBCXX_DEBUG
165    #include <algorithm>
166    int main(int argc, char** argv) {
167      static constexpr int data[] = {0, 1};
168      constexpr const int* min_elt = std::min_element(&data[0], &data[2]);
169      return 0;
170    }" CXX_SUPPORTS_GLIBCXX_DEBUG)
171  if(CXX_SUPPORTS_GLIBCXX_DEBUG)
172    add_compile_definitions(_GLIBCXX_DEBUG)
173  else()
174    add_compile_definitions(_GLIBCXX_ASSERTIONS)
175  endif()
176endif()
177
178if (LLVM_ENABLE_STRICT_FIXED_SIZE_VECTORS)
179  add_compile_definitions(STRICT_FIXED_SIZE_VECTORS)
180endif()
181
182string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
183
184if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "WITH_ASSERTS" )
185  if( LLVM_ENABLE_ASSERTIONS )
186    set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
187  endif()
188elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_ON" )
189  set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
190elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
191  # We don't need to do anything special to turn off ABI breaking checks.
192elseif( NOT DEFINED LLVM_ABI_BREAKING_CHECKS )
193  # Treat LLVM_ABI_BREAKING_CHECKS like "FORCE_OFF" when it has not been
194  # defined.
195else()
196  message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
197endif()
198
199if( LLVM_REVERSE_ITERATION )
200  set( LLVM_ENABLE_REVERSE_ITERATION 1 )
201endif()
202
203if(WIN32)
204  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
205  if(CYGWIN)
206    set(LLVM_ON_WIN32 0)
207    set(LLVM_ON_UNIX 1)
208  else(CYGWIN)
209    set(LLVM_ON_WIN32 1)
210    set(LLVM_ON_UNIX 0)
211  endif(CYGWIN)
212elseif(FUCHSIA OR UNIX)
213  set(LLVM_ON_WIN32 0)
214  set(LLVM_ON_UNIX 1)
215  if(APPLE OR ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
216    set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
217  else()
218    set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
219  endif()
220elseif(CMAKE_SYSTEM_NAME STREQUAL "Generic")
221  set(LLVM_ON_WIN32 0)
222  set(LLVM_ON_UNIX 0)
223  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
224else()
225  MESSAGE(SEND_ERROR "Unable to determine platform")
226endif()
227
228if (CMAKE_SYSTEM_NAME MATCHES "OS390")
229  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
230endif()
231
232set(EXEEXT ${CMAKE_EXECUTABLE_SUFFIX})
233set(LTDL_SHLIB_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
234
235# We use *.dylib rather than *.so on darwin, but we stick with *.so on AIX.
236if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
237  set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_MODULE_SUFFIX})
238else()
239  set(LLVM_PLUGIN_EXT ${CMAKE_SHARED_LIBRARY_SUFFIX})
240endif()
241
242if(APPLE)
243  # Darwin-specific linker flags for loadable modules.
244  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
245endif()
246
247if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
248  # RHEL7 has ar and ranlib being non-deterministic by default. The D flag forces determinism,
249  # however only GNU version of ar and ranlib (2.27) have this option.
250  # RHEL DTS7 is also affected by this, which uses GNU binutils 2.28
251  execute_process(COMMAND ${CMAKE_AR} rD t.a
252                  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
253                  RESULT_VARIABLE AR_RESULT
254                  OUTPUT_QUIET
255                  ERROR_QUIET
256                  )
257  if(${AR_RESULT} EQUAL 0)
258    execute_process(COMMAND ${CMAKE_RANLIB} -D t.a
259                    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
260                    RESULT_VARIABLE RANLIB_RESULT
261                    OUTPUT_QUIET
262                    ERROR_QUIET
263                    )
264    if(${RANLIB_RESULT} EQUAL 0)
265      set(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>"
266          CACHE STRING "archive create command")
267      set(CMAKE_C_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
268      set(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>" CACHE STRING "ranlib command")
269
270      set(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>"
271          CACHE STRING "archive create command")
272      set(CMAKE_CXX_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
273      set(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>" CACHE STRING "ranlib command")
274    endif()
275    file(REMOVE ${CMAKE_BINARY_DIR}/t.a)
276  endif()
277endif()
278
279if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
280  # -fPIC does not enable the large code model for GCC on AIX but does for XL.
281  if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
282    append("-mcmodel=large" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
283    append("-Wl,-bglink=large"
284        CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
285  elseif(CMAKE_CXX_COMPILER_ID MATCHES "XL")
286    # XL generates a small number of relocations not of the large model, -bbigtoc is needed.
287    append("-Wl,-bbigtoc"
288           CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
289    # The default behaviour on AIX processes dynamic initialization of non-local variables with
290    # static storage duration even for archive members that are otherwise unreferenced.
291    # Since `--whole-archive` is not used by the LLVM build to keep such initializations for Linux,
292    # we can limit the processing for archive members to only those that are otherwise referenced.
293    append("-bcdtors:mbr"
294           CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
295  endif()
296  if(BUILD_SHARED_LIBS)
297    # See rpath handling in AddLLVM.cmake
298    # FIXME: Remove this warning if this rpath is no longer hardcoded.
299    message(WARNING "Build and install environment path info may be exposed; binaries will also be unrelocatable.")
300  endif()
301endif()
302
303# Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
304# build might work on ELF but fail on MachO/COFF.
305if(NOT (CMAKE_SYSTEM_NAME MATCHES "Darwin|FreeBSD|OpenBSD|DragonFly|AIX|OS390" OR
306        WIN32 OR CYGWIN) AND
307   NOT LLVM_USE_SANITIZER)
308  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
309endif()
310
311# Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
312# by dlclose(). We need that since the CLI API relies on cross-references
313# between global objects which became horribly broken when one of the libraries
314# is unloaded.
315if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
316  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,nodelete")
317  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-z,nodelete")
318endif()
319
320
321function(append value)
322  foreach(variable ${ARGN})
323    set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
324  endforeach(variable)
325endfunction()
326
327function(append_if condition value)
328  if (${condition})
329    foreach(variable ${ARGN})
330      set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
331    endforeach(variable)
332  endif()
333endfunction()
334
335macro(add_flag_if_supported flag name)
336  check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
337  append_if("C_SUPPORTS_${name}" "${flag}" CMAKE_C_FLAGS)
338  check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
339  append_if("CXX_SUPPORTS_${name}" "${flag}" CMAKE_CXX_FLAGS)
340endmacro()
341
342function(add_flag_or_print_warning flag name)
343  check_c_compiler_flag("-Werror ${flag}" "C_SUPPORTS_${name}")
344  check_cxx_compiler_flag("-Werror ${flag}" "CXX_SUPPORTS_${name}")
345  if (C_SUPPORTS_${name} AND CXX_SUPPORTS_${name})
346    message(STATUS "Building with ${flag}")
347    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
348    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
349    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} ${flag}" PARENT_SCOPE)
350  else()
351    message(WARNING "${flag} is not supported.")
352  endif()
353endfunction()
354
355function(has_msvc_incremental_no_flag flags incr_no_flag_on)
356  set(${incr_no_flag_on} OFF PARENT_SCOPE)
357  string(FIND "${flags}" "/INCREMENTAL" idx REVERSE)
358  if (${idx} GREATER -1)
359    string(SUBSTRING "${flags}" ${idx} 15 no_flag)
360    if (${no_flag} MATCHES "/INCREMENTAL:NO")
361      set(${incr_no_flag_on} ON PARENT_SCOPE)
362    endif()
363  endif()
364endfunction()
365
366if( LLVM_ENABLE_LLD )
367  if ( LLVM_USE_LINKER )
368    message(FATAL_ERROR "LLVM_ENABLE_LLD and LLVM_USE_LINKER can't be set at the same time")
369  endif()
370
371  # In case of MSVC cmake always invokes the linker directly, so the linker
372  # should be specified by CMAKE_LINKER cmake variable instead of by -fuse-ld
373  # compiler option.
374  if ( MSVC )
375    if(NOT CMAKE_LINKER MATCHES "lld-link")
376      get_filename_component(CXX_COMPILER_DIR ${CMAKE_CXX_COMPILER} DIRECTORY)
377      get_filename_component(C_COMPILER_DIR ${CMAKE_C_COMPILER} DIRECTORY)
378      find_program(LLD_LINK NAMES "lld-link" "lld-link.exe" HINTS ${CXX_COMPILER_DIR} ${C_COMPILER_DIR} DOC "lld linker")
379      if(NOT LLD_LINK)
380        message(FATAL_ERROR
381          "LLVM_ENABLE_LLD set, but cannot find lld-link. "
382          "Consider setting CMAKE_LINKER to lld-link path.")
383      endif()
384      set(CMAKE_LINKER ${LLD_LINK})
385    endif()
386  else()
387    set(LLVM_USE_LINKER "lld")
388  endif()
389endif()
390
391if( LLVM_USE_LINKER )
392  append("-fuse-ld=${LLVM_USE_LINKER}"
393    CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
394  check_cxx_source_compiles("int main() { return 0; }" CXX_SUPPORTS_CUSTOM_LINKER)
395  if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
396    message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'. "
397                        "Please make sure that '${LLVM_USE_LINKER}' is installed and "
398                        "that your host compiler can compile a simple program when "
399                        "given the option '-fuse-ld=${LLVM_USE_LINKER}'.")
400  endif()
401endif()
402
403if( LLVM_ENABLE_PIC )
404  if( XCODE )
405    # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
406    # know how to disable this, so just force ENABLE_PIC off for now.
407    message(WARNING "-fPIC not supported with Xcode.")
408  elseif( WIN32 OR CYGWIN)
409    # On Windows all code is PIC. MinGW warns if -fPIC is used.
410  else()
411    add_flag_or_print_warning("-fPIC" FPIC)
412    # Enable interprocedural optimizations for non-inline functions which would
413    # otherwise be disabled due to GCC -fPIC's default.
414    # Note: GCC<10.3 has a bug on SystemZ.
415    #
416    # Note: Clang allows IPO for -fPIC so this optimization is less effective.
417    # Clang 13 has a bug related to -fsanitize-coverage
418    # -fno-semantic-interposition (https://reviews.llvm.org/D117183).
419    if ((CMAKE_COMPILER_IS_GNUCXX AND
420         NOT (LLVM_NATIVE_ARCH STREQUAL "SystemZ" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.3))
421       OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 14))
422      add_flag_if_supported("-fno-semantic-interposition" FNO_SEMANTIC_INTERPOSITION)
423    endif()
424  endif()
425  # GCC for MIPS can miscompile LLVM due to PR37701.
426  if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
427         NOT Uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
428    append("-fno-shrink-wrap" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
429  endif()
430  # gcc with -O3 -fPIC generates TLS sequences that violate the spec on
431  # Solaris/sparcv9, causing executables created with the system linker
432  # to SEGV (GCC PR target/96607).
433  # clang with -O3 -fPIC generates code that SEGVs.
434  # Both can be worked around by compiling with -O instead.
435  if(${CMAKE_SYSTEM_NAME} STREQUAL "SunOS" AND LLVM_NATIVE_ARCH STREQUAL "Sparc")
436    llvm_replace_compiler_option(CMAKE_CXX_FLAGS_RELEASE "-O[23]" "-O")
437    llvm_replace_compiler_option(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O[23]" "-O")
438  endif()
439endif()
440
441if((NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX")) AND
442   (NOT (WIN32 OR CYGWIN) OR (MINGW AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")))
443  # GCC for MinGW does nothing about -fvisibility-inlines-hidden, but warns
444  # about use of the attributes. As long as we don't use the attributes (to
445  # override the default) we shouldn't set the command line options either.
446  # GCC on AIX warns if -fvisibility-inlines-hidden is used and Clang on AIX doesn't currently support visibility.
447  check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
448  append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
449endif()
450
451if(CMAKE_SIZEOF_VOID_P EQUAL 8 AND MINGW)
452  add_compile_definitions(_FILE_OFFSET_BITS=64)
453endif()
454
455if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
456  # TODO: support other platforms and toolchains.
457  if( LLVM_BUILD_32_BITS )
458    message(STATUS "Building 32 bits executables and libraries.")
459    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
460    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
461    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
462    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
463    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
464
465    # FIXME: CMAKE_SIZEOF_VOID_P is still 8
466    add_compile_definitions(_LARGEFILE_SOURCE)
467    add_compile_definitions(_FILE_OFFSET_BITS=64)
468  endif( LLVM_BUILD_32_BITS )
469endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
470
471# If building on a GNU specific 32-bit system, make sure off_t is 64 bits
472# so that off_t can stored offset > 2GB.
473# Android until version N (API 24) doesn't support it.
474if (ANDROID AND (ANDROID_NATIVE_API_LEVEL LESS 24))
475  set(LLVM_FORCE_SMALLFILE_FOR_ANDROID TRUE)
476endif()
477if( CMAKE_SIZEOF_VOID_P EQUAL 4 AND NOT LLVM_FORCE_SMALLFILE_FOR_ANDROID)
478  # FIXME: It isn't handled in LLVM_BUILD_32_BITS.
479  add_compile_definitions(_LARGEFILE_SOURCE)
480  add_compile_definitions(_FILE_OFFSET_BITS=64)
481endif()
482
483if( XCODE )
484  # For Xcode enable several build settings that correspond to
485  # many warnings that are on by default in Clang but are
486  # not enabled for historical reasons.  For versions of Xcode
487  # that do not support these options they will simply
488  # be ignored.
489  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
490  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")
491  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VALUE "YES")
492  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_VARIABLE "YES")
493  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_SIGN_COMPARE "YES")
494  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNUSED_FUNCTION "YES")
495  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED "YES")
496  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS "YES")
497  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_UNINITIALIZED_AUTOS "YES")
498  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_BOOL_CONVERSION "YES")
499  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_EMPTY_BODY "YES")
500  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_ENUM_CONVERSION "YES")
501  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_INT_CONVERSION "YES")
502  set(CMAKE_XCODE_ATTRIBUTE_CLANG_WARN_CONSTANT_CONVERSION "YES")
503  set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_NON_VIRTUAL_DESTRUCTOR "YES")
504endif()
505
506# On Win32 using MS tools, provide an option to set the number of parallel jobs
507# to use.
508if( MSVC_IDE )
509  set(LLVM_COMPILER_JOBS "0" CACHE STRING
510    "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
511  if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
512    if( LLVM_COMPILER_JOBS STREQUAL "0" )
513      add_compile_options(/MP)
514    else()
515      message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
516      add_compile_options(/MP${LLVM_COMPILER_JOBS})
517    endif()
518  else()
519    message(STATUS "Parallel compilation disabled")
520  endif()
521endif()
522
523# set stack reserved size to ~10MB
524if(MSVC)
525  # CMake previously automatically set this value for MSVC builds, but the
526  # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
527  # value (1 MB) which is not enough for us in tasks such as parsing recursive
528  # C++ templates in Clang.
529  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
530elseif(MINGW OR CYGWIN)
531  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
532
533  # Pass -mbig-obj to mingw gas to avoid COFF 2**16 section limit.
534  if (NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
535    append("-Wa,-mbig-obj" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
536  endif()
537endif()
538
539option(LLVM_ENABLE_WARNINGS "Enable compiler warnings." ON)
540
541if( MSVC )
542
543  # Add definitions that make MSVC much less annoying.
544  add_compile_definitions(
545    # For some reason MS wants to deprecate a bunch of standard functions...
546    _CRT_SECURE_NO_DEPRECATE
547    _CRT_SECURE_NO_WARNINGS
548    _CRT_NONSTDC_NO_DEPRECATE
549    _CRT_NONSTDC_NO_WARNINGS
550    _SCL_SECURE_NO_DEPRECATE
551    _SCL_SECURE_NO_WARNINGS
552    )
553
554  # Tell MSVC to use the Unicode version of the Win32 APIs instead of ANSI.
555  add_compile_definitions(
556    UNICODE
557    _UNICODE
558  )
559
560  if (LLVM_WINSYSROOT)
561    if (NOT CLANG_CL)
562      message(ERROR "LLVM_WINSYSROOT requires clang-cl")
563    endif()
564    append("/winsysroot${LLVM_WINSYSROOT}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
565    if (LINKER_IS_LLD_LINK)
566      append("/winsysroot:${LLVM_WINSYSROOT}"
567          CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS
568          CMAKE_SHARED_LINKER_FLAGS)
569    endif()
570  endif()
571
572  if (LLVM_ENABLE_WERROR)
573    append("/WX" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
574  endif (LLVM_ENABLE_WERROR)
575
576  append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
577
578  if (NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
579    # Enable standards-conforming preprocessor.
580    # https://learn.microsoft.com/en-us/cpp/build/reference/zc-preprocessor
581    append("/Zc:preprocessor" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
582  endif ()
583
584  # Some projects use the __cplusplus preprocessor macro to check support for
585  # a particular version of the C++ standard. When this option is not specified
586  # explicitly, macro's value is "199711L" that implies C++98 Standard.
587  # https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
588  append("/Zc:__cplusplus" CMAKE_CXX_FLAGS)
589
590  # Allow users to request PDBs in release mode. CMake offeres the
591  # RelWithDebInfo configuration, but it uses different optimization settings
592  # (/Ob1 vs /Ob2 or -O2 vs -O3). LLVM provides this flag so that users can get
593  # PDBs without changing codegen.
594  option(LLVM_ENABLE_PDB OFF)
595  if (LLVM_ENABLE_PDB AND uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
596    append("/Zi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
597    # /DEBUG disables linker GC and ICF, but we want those in Release mode.
598    append("/DEBUG /OPT:REF /OPT:ICF"
599          CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS
600          CMAKE_SHARED_LINKER_FLAGS)
601  endif()
602
603  # Get all linker flags in upper case form so we can search them.
604  string(CONCAT all_linker_flags_uppercase
605     ${CMAKE_EXE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
606     ${CMAKE_EXE_LINKER_FLAGS} " "
607     ${CMAKE_MODULE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
608     ${CMAKE_MODULE_LINKER_FLAGS} " "
609     ${CMAKE_SHARED_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} " "
610     ${CMAKE_SHARED_LINKER_FLAGS})
611  string(TOUPPER "${all_linker_flags_uppercase}" all_linker_flags_uppercase)
612
613  if (CLANG_CL AND LINKER_IS_LLD)
614    # If we are using clang-cl with lld-link and /debug is present in any of the
615    # linker flag variables, pass -gcodeview-ghash to the compiler to speed up
616    # linking. This flag is orthogonal from /Zi, /Z7, and other flags that
617    # enable debug info emission, and only has an effect if those are also in
618    # use.
619    string(FIND "${all_linker_flags_uppercase}" "/DEBUG" linker_flag_idx)
620    if (${linker_flag_idx} GREATER -1)
621      add_flag_if_supported("-gcodeview-ghash" GCODEVIEW_GHASH)
622    endif()
623  endif()
624
625  # "Generate Intrinsic Functions".
626  append("/Oi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
627
628  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT LLVM_ENABLE_LTO)
629    # clang-cl and cl by default produce non-deterministic binaries because
630    # link.exe /incremental requires a timestamp in the .obj file.  clang-cl
631    # has the flag /Brepro to force deterministic binaries. We want to pass that
632    # whenever you're building with clang unless you're passing /incremental
633    # or using LTO (/Brepro with LTO would result in a warning about the flag
634    # being unused, because we're not generating object files).
635    # This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag()
636    # because cl.exe does not emit an error on flags it doesn't understand,
637    # letting check_cxx_compiler_flag() claim it understands all flags.
638
639    # Check if /INCREMENTAL is passed to the linker and complain that it
640    # won't work with /Brepro.
641    has_msvc_incremental_no_flag("${CMAKE_EXE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_EXE_LINKER_FLAGS}" NO_INCR_EXE)
642    has_msvc_incremental_no_flag("${CMAKE_MODULE_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_MODULE_LINKER_FLAGS}" NO_INCR_MODULE)
643    has_msvc_incremental_no_flag("${CMAKE_SHARED_LINKER_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_SHARED_LINKER_FLAGS}" NO_INCR_SHARED)
644    if (NO_INCR_EXE AND NO_INCR_MODULE AND NO_INCR_SHARED)
645      append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
646    else()
647      message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic")
648    endif()
649  endif()
650  # By default MSVC has a 2^16 limit on the number of sections in an object file,
651  # but in many objects files need more than that. This flag is to increase the
652  # number of sections.
653  append("/bigobj" CMAKE_CXX_FLAGS)
654
655  # Enable standards conformance mode.
656  # This ensures handling of various C/C++ constructs is more similar to other compilers.
657  append("/permissive-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
658endif( MSVC )
659
660# Warnings-as-errors handling for GCC-compatible compilers:
661if ( LLVM_COMPILER_IS_GCC_COMPATIBLE )
662  append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
663  append_if(LLVM_ENABLE_WERROR "-Wno-error" CMAKE_REQUIRED_FLAGS)
664endif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
665
666# Specific default warnings-as-errors for compilers accepting GCC-compatible warning flags:
667if ( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
668  append("-Werror=date-time" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
669endif( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
670
671if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
672  append("-Werror=unguarded-availability-new" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
673endif()
674
675if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
676  # LLVM data structures like llvm::User and llvm::MDNode rely on
677  # the value of object storage persisting beyond the lifetime of the
678  # object (#24952).  This is not standard compliant and causes a runtime
679  # crash if LLVM is built with GCC and LTO enabled (#57740).  Until
680  # these bugs are fixed, we need to disable dead store eliminations
681  # based on object lifetime.
682  append("-fno-lifetime-dse" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
683endif ()
684
685# Modules enablement for GCC-compatible compilers:
686if ( LLVM_COMPILER_IS_GCC_COMPATIBLE AND LLVM_ENABLE_MODULES )
687  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
688  set(module_flags "-fmodules -fmodules-cache-path=${PROJECT_BINARY_DIR}/module.cache")
689  if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
690    # On Darwin -fmodules does not imply -fcxx-modules.
691    set(module_flags "${module_flags} -fcxx-modules")
692  endif()
693  if (LLVM_ENABLE_LOCAL_SUBMODULE_VISIBILITY)
694    set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility")
695  endif()
696  if (LLVM_ENABLE_MODULE_DEBUGGING AND
697      ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
698       (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
699    set(module_flags "${module_flags} -gmodules")
700  endif()
701  append("${module_flags}" CMAKE_CXX_FLAGS)
702endif( LLVM_COMPILER_IS_GCC_COMPATIBLE AND LLVM_ENABLE_MODULES )
703
704if (MSVC)
705  if (NOT CLANG_CL)
706    set(msvc_warning_flags
707      # Disabled warnings.
708      -wd4141 # Suppress ''modifier' : used more than once' (because of __forceinline combined with inline)
709      -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
710      -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
711      -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
712      -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
713      -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
714      -wd4456 # Suppress 'declaration of 'var' hides local variable'
715      -wd4457 # Suppress 'declaration of 'var' hides function parameter'
716      -wd4458 # Suppress 'declaration of 'var' hides class member'
717      -wd4459 # Suppress 'declaration of 'var' hides global declaration'
718      -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
719      -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
720      -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
721      -wd4100 # Suppress 'unreferenced formal parameter'
722      -wd4127 # Suppress 'conditional expression is constant'
723      -wd4512 # Suppress 'assignment operator could not be generated'
724      -wd4505 # Suppress 'unreferenced local function has been removed'
725      -wd4610 # Suppress '<class> can never be instantiated'
726      -wd4510 # Suppress 'default constructor could not be generated'
727      -wd4702 # Suppress 'unreachable code'
728      -wd4245 # Suppress ''conversion' : conversion from 'type1' to 'type2', signed/unsigned mismatch'
729      -wd4706 # Suppress 'assignment within conditional expression'
730      -wd4310 # Suppress 'cast truncates constant value'
731      -wd4701 # Suppress 'potentially uninitialized local variable'
732      -wd4703 # Suppress 'potentially uninitialized local pointer variable'
733      -wd4389 # Suppress 'signed/unsigned mismatch'
734      -wd4611 # Suppress 'interaction between '_setjmp' and C++ object destruction is non-portable'
735      -wd4805 # Suppress 'unsafe mix of type <type> and type <type> in operation'
736      -wd4204 # Suppress 'nonstandard extension used : non-constant aggregate initializer'
737      -wd4577 # Suppress 'noexcept used with no exception handling mode specified; termination on exception is not guaranteed'
738      -wd4091 # Suppress 'typedef: ignored on left of '' when no variable is declared'
739          # C4592 is disabled because of false positives in Visual Studio 2015
740          # Update 1. Re-evaluate the usefulness of this diagnostic with Update 2.
741      -wd4592 # Suppress ''var': symbol will be dynamically initialized (implementation limitation)
742      -wd4319 # Suppress ''operator' : zero extending 'type' to 'type' of greater size'
743          # C4709 is disabled because of a bug with Visual Studio 2017 as of
744          # v15.8.8. Re-evaluate the usefulness of this diagnostic when the bug
745          # is fixed.
746      -wd4709 # Suppress comma operator within array index expression
747
748      # We'd like this warning to be enabled, but it triggers from code in
749      # WinBase.h that we don't have control over.
750      -wd5105 # Suppress macro expansion producing 'defined' has undefined behavior
751
752      # Ideally, we'd like this warning to be enabled, but even MSVC 2019 doesn't
753      # support the 'aligned' attribute in the way that clang sources requires (for
754      # any code that uses the LLVM_ALIGNAS macro), so this is must be disabled to
755      # avoid unwanted alignment warnings.
756      -wd4324 # Suppress 'structure was padded due to __declspec(align())'
757
758      # Promoted warnings.
759      -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
760
761      # Promoted warnings to errors.
762      -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
763      )
764  endif(NOT CLANG_CL)
765
766  # Enable warnings
767  if (LLVM_ENABLE_WARNINGS)
768    # Put /W4 in front of all the -we flags. cl.exe doesn't care, but for
769    # clang-cl having /W4 after the -we flags will re-enable the warnings
770    # disabled by -we.
771    set(msvc_warning_flags "/W4 ${msvc_warning_flags}")
772    # CMake appends /W3 by default, and having /W3 followed by /W4 will result in
773    # cl : Command line warning D9025 : overriding '/W3' with '/W4'.  Since this is
774    # a command line warning and not a compiler warning, it cannot be suppressed except
775    # by fixing the command line.
776    string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
777    string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
778
779    if (LLVM_ENABLE_PEDANTIC)
780      # No MSVC equivalent available
781    endif (LLVM_ENABLE_PEDANTIC)
782  endif (LLVM_ENABLE_WARNINGS)
783
784  foreach(flag ${msvc_warning_flags})
785    append("${flag}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
786  endforeach(flag)
787endif (MSVC)
788
789if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
790
791  # Don't add -Wall for clang-cl, because it maps -Wall to -Weverything for
792  # MSVC compatibility.  /W4 is added above instead.
793  if (NOT CLANG_CL)
794    append("-Wall" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
795  endif()
796
797  append("-Wextra -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
798  append("-Wcast-qual" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
799
800  # Turn off missing field initializer warnings for gcc to avoid noise from
801  # false positives with empty {}. Turn them on otherwise (they're off by
802  # default for clang).
803  if (CMAKE_COMPILER_IS_GNUCXX)
804    append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
805  else()
806    append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
807  endif()
808
809  if (LLVM_ENABLE_PEDANTIC AND LLVM_COMPILER_IS_GCC_COMPATIBLE)
810    append("-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
811    append("-Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
812
813    # GCC warns about redundant toplevel semicolons (enabled by -pedantic
814    # above), while Clang doesn't. Enable the corresponding Clang option to
815    # pick up on these even in builds with Clang.
816    add_flag_if_supported("-Wc++98-compat-extra-semi" CXX98_COMPAT_EXTRA_SEMI_FLAG)
817  endif()
818
819  append("-Wimplicit-fallthrough" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
820
821  set(CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG 0)
822  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
823    set(CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG 1)
824    append("-Wcovered-switch-default" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
825  endif()
826  append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
827  append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
828
829  # Disable -Wnonnull for GCC warning as it is emitting a lot of false positives.
830  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
831    append("-Wno-nonnull" CMAKE_CXX_FLAGS)
832  endif()
833
834  # Disable -Wclass-memaccess, a C++-only warning from GCC 8 that fires on
835  # LLVM's ADT classes.
836  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
837    if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8.1)
838      append("-Wno-class-memaccess" CMAKE_CXX_FLAGS)
839    endif()
840  endif()
841
842  # Disable -Wredundant-move and -Wpessimizing-move on GCC>=9. GCC wants to
843  # remove std::move in code like
844  # "A foo(ConvertibleToA a) { return std::move(a); }",
845  # but this code does not compile (or uses the copy
846  # constructor instead) on clang<=3.8. Clang also has a -Wredundant-move and
847  # -Wpessimizing-move, but they only fire when the types match exactly, so we
848  # can keep them here.
849  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
850    if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 9.1)
851      append("-Wno-redundant-move" CMAKE_CXX_FLAGS)
852      append("-Wno-pessimizing-move" CMAKE_CXX_FLAGS)
853    endif()
854  endif()
855
856  # The LLVM libraries have no stable C++ API, so -Wnoexcept-type is not useful.
857  append("-Wno-noexcept-type" CMAKE_CXX_FLAGS)
858
859  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
860    append("-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
861  endif()
862  append("-Wdelete-non-virtual-dtor" CMAKE_CXX_FLAGS)
863
864  # Enable -Wsuggest-override if it's available, and only if it doesn't
865  # suggest adding 'override' to functions that are already marked 'final'
866  # (which means it is disabled for GCC < 9.2).
867  check_cxx_compiler_flag("-Wsuggest-override" CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
868  if (CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
869    set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
870    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=suggest-override")
871    CHECK_CXX_SOURCE_COMPILES("class base {public: virtual void anchor();};
872                               class derived : base {public: void anchor() final;};
873                               int main() { return 0; }"
874                              CXX_WSUGGEST_OVERRIDE_ALLOWS_ONLY_FINAL)
875    set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
876    append_if(CXX_WSUGGEST_OVERRIDE_ALLOWS_ONLY_FINAL "-Wsuggest-override" CMAKE_CXX_FLAGS)
877  endif()
878
879  # Check if -Wcomment is OK with an // comment ending with '\' if the next
880  # line is also a // comment.
881  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
882  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wcomment")
883  CHECK_C_SOURCE_COMPILES("// \\\\\\n//\\nint main(void) {return 0;}"
884                          C_WCOMMENT_ALLOWS_LINE_WRAP)
885  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
886  if (NOT C_WCOMMENT_ALLOWS_LINE_WRAP)
887    append("-Wno-comment" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
888  endif()
889
890  # Enable -Wstring-conversion to catch misuse of string literals.
891  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
892    append("-Wstring-conversion" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
893  endif()
894
895  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
896    # Disable the misleading indentation warning with GCC; GCC can
897    # produce noisy notes about this getting disabled in large files.
898    # See e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89549
899    append("-Wno-misleading-indentation" CMAKE_CXX_FLAGS)
900  else()
901    # Prevent bugs that can happen with llvm's brace style.
902    add_flag_if_supported("-Wmisleading-indentation" MISLEADING_INDENTATION_FLAG)
903  endif()
904
905  # Enable -Wctad-maybe-unsupported to catch unintended use of CTAD.
906  add_flag_if_supported("-Wctad-maybe-unsupported" CTAD_MAYBE_UNSPPORTED_FLAG)
907endif (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
908
909if (LLVM_COMPILER_IS_GCC_COMPATIBLE AND NOT LLVM_ENABLE_WARNINGS)
910  append("-w" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
911endif()
912
913macro(append_common_sanitizer_flags)
914  if (NOT MSVC OR CLANG_CL)
915    # Append -fno-omit-frame-pointer and turn on debug info to get better
916    # stack traces.
917    append("-fno-omit-frame-pointer" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
918    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
919        NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO" AND
920        CMAKE_CXX_COMPILER_ID MATCHES "Clang")
921      append("-gline-tables-only" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
922    endif()
923    # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
924    if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND LLVM_OPTIMIZE_SANITIZED_BUILDS)
925      append("-O1" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
926    endif()
927  else()
928    # Always ask the linker to produce symbols with asan.
929    append("/Z7" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
930    append("/debug" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
931    # Not compatible with /INCREMENTAL link.
932    foreach (flags_opt_to_scrub
933        CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
934      string (REGEX REPLACE "(^| )/INCREMENTAL($| )" " /INCREMENTAL:NO "
935        "${flags_opt_to_scrub}" "${${flags_opt_to_scrub}}")
936    endforeach()
937    if (LLVM_HOST_TRIPLE MATCHES "i[2-6]86-.*")
938      # Keep frame pointers around.
939      append("/Oy-" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
940    endif()
941  endif()
942endmacro()
943
944# Turn on sanitizers if necessary.
945if(LLVM_USE_SANITIZER)
946  if (LLVM_ON_UNIX)
947    if (LLVM_USE_SANITIZER STREQUAL "Address")
948      append_common_sanitizer_flags()
949      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
950    elseif (LLVM_USE_SANITIZER STREQUAL "HWAddress")
951      append_common_sanitizer_flags()
952      append("-fsanitize=hwaddress" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
953    elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
954      append_common_sanitizer_flags()
955      append("-fsanitize=memory" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
956      if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
957        append("-fsanitize-memory-track-origins" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
958      endif()
959    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
960      append_common_sanitizer_flags()
961      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
962    elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
963      append_common_sanitizer_flags()
964      append("-fsanitize=thread" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
965    elseif (LLVM_USE_SANITIZER STREQUAL "DataFlow")
966      append("-fsanitize=dataflow" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
967    elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
968            LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
969      append_common_sanitizer_flags()
970      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
971      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
972    elseif (LLVM_USE_SANITIZER STREQUAL "Leaks")
973      append_common_sanitizer_flags()
974      append("-fsanitize=leak" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
975    else()
976      message(FATAL_ERROR "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
977    endif()
978  elseif(MINGW)
979    if (LLVM_USE_SANITIZER STREQUAL "Address")
980      append_common_sanitizer_flags()
981      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
982    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
983      append_common_sanitizer_flags()
984      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
985    elseif (LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
986            LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
987      append_common_sanitizer_flags()
988      append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
989      append("${LLVM_UBSAN_FLAGS}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
990    else()
991      message(FATAL_ERROR "This sanitizer not yet supported in a MinGW environment: ${LLVM_USE_SANITIZER}")
992    endif()
993  elseif(MSVC)
994    if (NOT LLVM_USE_SANITIZER MATCHES "^(Address|Undefined|Address;Undefined|Undefined;Address)$")
995      message(FATAL_ERROR "This sanitizer not yet supported in the MSVC environment: ${LLVM_USE_SANITIZER}")
996    endif()
997    append_common_sanitizer_flags()
998    if (LINKER_IS_LLD_LINK)
999      if (LLVM_HOST_TRIPLE MATCHES "i[2-6]86-.*")
1000        set(arch "i386")
1001      else()
1002        set(arch "x86_64")
1003      endif()
1004      # Prepare ASAN runtime if needed
1005      if (LLVM_USE_SANITIZER MATCHES ".*Address.*")
1006        # lld string tail merging interacts badly with ASAN on Windows, turn it off here
1007        # See https://github.com/llvm/llvm-project/issues/62078
1008        append("/opt:nolldtailmerge" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1009        if (${CMAKE_MSVC_RUNTIME_LIBRARY} MATCHES "^(MultiThreaded|MultiThreadedDebug)$")
1010          append("/wholearchive:clang_rt.asan-${arch}.lib /wholearchive:clang_rt.asan_cxx-${arch}.lib"
1011            CMAKE_EXE_LINKER_FLAGS)
1012          append("/wholearchive:clang_rt.asan_dll_thunk-${arch}.lib"
1013            CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1014        else()
1015          append("clang_rt.asan_dynamic-${arch}.lib /wholearchive:clang_rt.asan_dynamic_runtime_thunk-${arch}.lib"
1016            CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1017        endif()
1018      endif()
1019    endif()
1020    if (LLVM_USE_SANITIZER MATCHES ".*Address.*")
1021      if (NOT CLANG_CL)
1022        append("/fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1023        # Not compatible with /RTC flags.
1024        foreach (flags_opt_to_scrub
1025            CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE} CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE})
1026          string (REGEX REPLACE "(^| )/RTC[1csu]*($| )" " "
1027            "${flags_opt_to_scrub}" "${${flags_opt_to_scrub}}")
1028        endforeach()
1029      else()
1030        append("-fsanitize=address" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1031      endif()
1032    endif()
1033    if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
1034      if (NOT CLANG_CL)
1035        message(FATAL_ERROR "This sanitizer is only supported by clang-cl: Undefined")
1036      endif()
1037      append(${LLVM_UBSAN_FLAGS} CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1038    endif()
1039  else()
1040    message(FATAL_ERROR "LLVM_USE_SANITIZER is not supported on this platform.")
1041  endif()
1042  if (LLVM_USE_SANITIZE_COVERAGE)
1043    append("-fsanitize=fuzzer-no-link" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1044  endif()
1045  if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
1046    set(IGNORELIST_FILE "${PROJECT_SOURCE_DIR}/utils/sanitizers/ubsan_ignorelist.txt")
1047    if (EXISTS "${IGNORELIST_FILE}")
1048      # Use this option name version since -fsanitize-ignorelist is only
1049      # accepted with clang 13.0 or newer.
1050      append("-fsanitize-blacklist=${IGNORELIST_FILE}"
1051             CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1052    endif()
1053  endif()
1054endif()
1055
1056# Turn on -gsplit-dwarf if requested in debug builds.
1057if (LLVM_USE_SPLIT_DWARF AND
1058    ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
1059     (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
1060  # Limit to clang and gcc so far. Add compilers supporting this option.
1061  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
1062      CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
1063    add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-gsplit-dwarf>)
1064    include(CheckLinkerFlag)
1065    check_linker_flag(CXX "-Wl,--gdb-index" LINKER_SUPPORTS_GDB_INDEX)
1066    append_if(LINKER_SUPPORTS_GDB_INDEX "-Wl,--gdb-index"
1067      CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1068  endif()
1069endif()
1070
1071add_compile_definitions(__STDC_CONSTANT_MACROS)
1072add_compile_definitions(__STDC_FORMAT_MACROS)
1073add_compile_definitions(__STDC_LIMIT_MACROS)
1074
1075# clang and gcc don't default-print colored diagnostics when invoked from Ninja.
1076if (UNIX AND
1077    CMAKE_GENERATOR MATCHES "Ninja" AND
1078    (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
1079     (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND
1080      NOT (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9))))
1081  append("-fdiagnostics-color" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1082endif()
1083
1084# lld doesn't print colored diagnostics when invoked from Ninja
1085if (UNIX AND CMAKE_GENERATOR MATCHES "Ninja")
1086  include(CheckLinkerFlag)
1087  check_linker_flag(CXX "-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
1088  append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,--color-diagnostics"
1089    CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1090endif()
1091
1092# Add flags for add_dead_strip().
1093# FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
1094# But MinSizeRel seems to add that automatically, so maybe disable these
1095# flags instead if LLVM_NO_DEAD_STRIP is set.
1096if(NOT CYGWIN AND NOT MSVC)
1097  if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
1098     NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
1099    if (CMAKE_CXX_COMPILER_ID MATCHES "XL")
1100      append("-qfuncsect" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1101    else()
1102      append("-ffunction-sections" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1103    endif()
1104    append("-fdata-sections" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1105  endif()
1106elseif(MSVC)
1107  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
1108    append("/Gw" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1109  endif()
1110endif()
1111
1112if(MSVC)
1113  # Remove flags here, for exceptions and RTTI.
1114  # Each target property or source property should be responsible to control
1115  # them.
1116  # CL.EXE complains to override flags like "/GR /GR-".
1117  string(REGEX REPLACE "(^| ) */EH[-cs]+ *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
1118  string(REGEX REPLACE "(^| ) */GR-? *( |$)" "\\1 \\2" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
1119endif()
1120
1121# Provide public options to globally control RTTI and EH
1122option(LLVM_ENABLE_EH "Enable Exception handling" OFF)
1123option(LLVM_ENABLE_RTTI "Enable run time type information" OFF)
1124if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
1125  message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
1126endif()
1127
1128option(LLVM_ENABLE_IR_PGO "Build LLVM and tools with IR PGO instrumentation (deprecated)" Off)
1129mark_as_advanced(LLVM_ENABLE_IR_PGO)
1130
1131set(LLVM_BUILD_INSTRUMENTED OFF CACHE STRING "Build LLVM and tools with PGO instrumentation. May be specified as IR or Frontend")
1132set(LLVM_VP_COUNTERS_PER_SITE "1.5" CACHE STRING "Value profile counters to use per site for IR PGO with Clang")
1133mark_as_advanced(LLVM_BUILD_INSTRUMENTED LLVM_VP_COUNTERS_PER_SITE)
1134string(TOUPPER "${LLVM_BUILD_INSTRUMENTED}" uppercase_LLVM_BUILD_INSTRUMENTED)
1135
1136if (LLVM_BUILD_INSTRUMENTED)
1137  if (LLVM_ENABLE_IR_PGO OR uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "IR")
1138    append("-fprofile-generate=\"${LLVM_PROFILE_DATA_DIR}\""
1139      CMAKE_CXX_FLAGS
1140      CMAKE_C_FLAGS)
1141    if(NOT LINKER_IS_LLD_LINK)
1142      append("-fprofile-generate=\"${LLVM_PROFILE_DATA_DIR}\""
1143        CMAKE_EXE_LINKER_FLAGS
1144        CMAKE_SHARED_LINKER_FLAGS)
1145    endif()
1146    # Set this to avoid running out of the value profile node section
1147    # under clang in dynamic linking mode.
1148    if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
1149        CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 11 AND
1150        LLVM_LINK_LLVM_DYLIB)
1151      append("-Xclang -mllvm -Xclang -vp-counters-per-site=${LLVM_VP_COUNTERS_PER_SITE}"
1152        CMAKE_CXX_FLAGS
1153        CMAKE_C_FLAGS)
1154    endif()
1155  elseif(uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "CSIR")
1156    append("-fcs-profile-generate=\"${LLVM_CSPROFILE_DATA_DIR}\""
1157      CMAKE_CXX_FLAGS
1158      CMAKE_C_FLAGS)
1159    if(NOT LINKER_IS_LLD_LINK)
1160      append("-fcs-profile-generate=\"${LLVM_CSPROFILE_DATA_DIR}\""
1161        CMAKE_EXE_LINKER_FLAGS
1162        CMAKE_SHARED_LINKER_FLAGS)
1163    endif()
1164  else()
1165    append("-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\""
1166      CMAKE_CXX_FLAGS
1167      CMAKE_C_FLAGS)
1168    if(NOT LINKER_IS_LLD_LINK)
1169      append("-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\""
1170        CMAKE_EXE_LINKER_FLAGS
1171        CMAKE_SHARED_LINKER_FLAGS)
1172    endif()
1173  endif()
1174endif()
1175
1176# When using clang-cl with an instrumentation-based tool, add clang's library
1177# resource directory to the library search path. Because cmake invokes the
1178# linker directly, it isn't sufficient to pass -fsanitize=* to the linker.
1179if (CLANG_CL AND (LLVM_BUILD_INSTRUMENTED OR LLVM_USE_SANITIZER))
1180  execute_process(
1181    COMMAND ${CMAKE_CXX_COMPILER} /clang:-print-libgcc-file-name /clang:--rtlib=compiler-rt
1182    OUTPUT_VARIABLE clang_compiler_rt_file
1183    ERROR_VARIABLE clang_cl_stderr
1184    OUTPUT_STRIP_TRAILING_WHITESPACE
1185    ERROR_STRIP_TRAILING_WHITESPACE
1186    RESULT_VARIABLE clang_cl_exit_code)
1187  if (NOT "${clang_cl_exit_code}" STREQUAL "0")
1188    message(FATAL_ERROR
1189      "Unable to invoke clang-cl to find resource dir: ${clang_cl_stderr}")
1190  endif()
1191  file(TO_CMAKE_PATH "${clang_compiler_rt_file}" clang_compiler_rt_file)
1192  get_filename_component(clang_runtime_dir "${clang_compiler_rt_file}" DIRECTORY)
1193  append("/libpath:\"${clang_runtime_dir}\""
1194    CMAKE_EXE_LINKER_FLAGS
1195    CMAKE_MODULE_LINKER_FLAGS
1196    CMAKE_SHARED_LINKER_FLAGS)
1197endif()
1198
1199if(LLVM_PROFDATA_FILE AND EXISTS ${LLVM_PROFDATA_FILE})
1200  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
1201    append("-fprofile-instr-use=\"${LLVM_PROFDATA_FILE}\""
1202      CMAKE_CXX_FLAGS
1203      CMAKE_C_FLAGS)
1204    if(NOT LINKER_IS_LLD_LINK)
1205      append("-fprofile-instr-use=\"${LLVM_PROFDATA_FILE}\""
1206        CMAKE_EXE_LINKER_FLAGS
1207        CMAKE_SHARED_LINKER_FLAGS)
1208    endif()
1209  else()
1210    message(FATAL_ERROR "LLVM_PROFDATA_FILE can only be specified when compiling with clang")
1211  endif()
1212endif()
1213
1214option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation" Off)
1215option(LLVM_INDIVIDUAL_TEST_COVERAGE "Emit individual coverage file for each test case." OFF)
1216mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE)
1217append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate=\"${LLVM_PROFILE_FILE_PATTERN}\" -fcoverage-mapping"
1218  CMAKE_CXX_FLAGS
1219  CMAKE_C_FLAGS
1220  CMAKE_EXE_LINKER_FLAGS
1221  CMAKE_SHARED_LINKER_FLAGS)
1222
1223if (LLVM_BUILD_INSTRUMENTED AND LLVM_BUILD_INSTRUMENTED_COVERAGE)
1224  message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
1225endif()
1226
1227set(LLVM_THINLTO_CACHE_PATH "${PROJECT_BINARY_DIR}/lto.cache" CACHE STRING "Set ThinLTO cache path. This can be used when building LLVM from several different directiories.")
1228
1229if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK AND NOT MINGW)
1230  message(FATAL_ERROR "When compiling for Windows, LLVM_ENABLE_LTO requires using lld as the linker (point CMAKE_LINKER at lld-link.exe)")
1231endif()
1232if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
1233  append("-flto=thin" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1234  if(NOT LINKER_IS_LLD_LINK)
1235    append("-flto=thin" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1236  endif()
1237  # If the linker supports it, enable the lto cache. This improves initial build
1238  # time a little since we re-link a lot of the same objects, and significantly
1239  # improves incremental build time.
1240  # FIXME: We should move all this logic into the clang driver.
1241  if(APPLE)
1242    append("-Wl,-cache_path_lto,${LLVM_THINLTO_CACHE_PATH}"
1243           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1244  elseif((UNIX OR MINGW) AND LLVM_USE_LINKER STREQUAL "lld")
1245    append("-Wl,--thinlto-cache-dir=${LLVM_THINLTO_CACHE_PATH}"
1246           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1247  elseif(LLVM_USE_LINKER STREQUAL "gold")
1248    append("-Wl,--plugin-opt,cache-dir=${LLVM_THINLTO_CACHE_PATH}"
1249           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1250  elseif(LINKER_IS_LLD_LINK)
1251    append("/lldltocache:${LLVM_THINLTO_CACHE_PATH}"
1252           CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1253  endif()
1254elseif(uppercase_LLVM_ENABLE_LTO STREQUAL "FULL")
1255  append("-flto=full" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1256  if(NOT LINKER_IS_LLD_LINK)
1257    append("-flto=full" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1258  endif()
1259elseif(LLVM_ENABLE_LTO)
1260  append("-flto" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
1261  if(NOT LINKER_IS_LLD_LINK)
1262    append("-flto" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
1263  endif()
1264endif()
1265
1266if(LLVM_ENABLE_FATLTO AND UNIX AND NOT APPLE)
1267  append("-ffat-lto-objects" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1268  if(NOT LINKER_IS_LLD_LINK)
1269    append("-ffat-lto-objects" CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS)
1270  endif()
1271endif()
1272
1273# Set an AIX default for LLVM_EXPORT_SYMBOLS_FOR_PLUGINS based on whether we are
1274# doing dynamic linking (see below).
1275set(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default OFF)
1276if (NOT (BUILD_SHARED_LIBS OR LLVM_LINK_LLVM_DYLIB))
1277  set(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default ON)
1278endif()
1279
1280# This option makes utils/extract_symbols.py be used to determine the list of
1281# symbols to export from LLVM tools. This is necessary when on AIX or when using
1282# MSVC if you want to allow plugins. On AIX we don't show this option, and we
1283# enable it by default except when the LLVM libraries are set up for dynamic
1284# linking (due to incompatibility). With MSVC, note that the plugin has to
1285# explicitly link against (exactly one) tool so we can't unilaterally turn on
1286# LLVM_ENABLE_PLUGINS when it's enabled.
1287CMAKE_DEPENDENT_OPTION(LLVM_EXPORT_SYMBOLS_FOR_PLUGINS
1288       "Export symbols from LLVM tools so that plugins can import them" OFF
1289       "NOT ${CMAKE_SYSTEM_NAME} MATCHES AIX" ${LLVM_EXPORT_SYMBOLS_FOR_PLUGINS_AIX_default})
1290if(BUILD_SHARED_LIBS AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
1291  message(FATAL_ERROR "BUILD_SHARED_LIBS not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
1292endif()
1293if(LLVM_LINK_LLVM_DYLIB AND LLVM_EXPORT_SYMBOLS_FOR_PLUGINS)
1294  message(FATAL_ERROR "LLVM_LINK_LLVM_DYLIB not compatible with LLVM_EXPORT_SYMBOLS_FOR_PLUGINS")
1295endif()
1296
1297# By default we should enable LLVM_ENABLE_IDE only for multi-configuration
1298# generators. This option disables optional build system features that make IDEs
1299# less usable.
1300set(LLVM_ENABLE_IDE_default OFF)
1301if (CMAKE_CONFIGURATION_TYPES)
1302  set(LLVM_ENABLE_IDE_default ON)
1303endif()
1304option(LLVM_ENABLE_IDE
1305       "Disable optional build system features that cause problems for IDE generators"
1306       ${LLVM_ENABLE_IDE_default})
1307if (CMAKE_CONFIGURATION_TYPES AND NOT LLVM_ENABLE_IDE)
1308  message(WARNING "Disabling LLVM_ENABLE_IDE on multi-configuration generators is not recommended.")
1309endif()
1310
1311function(get_compile_definitions)
1312  get_directory_property(top_dir_definitions DIRECTORY ${CMAKE_SOURCE_DIR} COMPILE_DEFINITIONS)
1313  foreach(definition ${top_dir_definitions})
1314    if(DEFINED result)
1315      string(APPEND result " -D${definition}")
1316    else()
1317      set(result "-D${definition}")
1318    endif()
1319  endforeach()
1320  set(LLVM_DEFINITIONS "${result}" PARENT_SCOPE)
1321endfunction()
1322get_compile_definitions()
1323
1324option(LLVM_FORCE_ENABLE_STATS "Enable statistics collection for builds that wouldn't normally enable it" OFF)
1325
1326check_symbol_exists(os_signpost_interval_begin "os/signpost.h" macos_signposts_available)
1327if(macos_signposts_available)
1328  check_cxx_source_compiles(
1329    "#include <os/signpost.h>
1330    int main() { os_signpost_interval_begin(nullptr, 0, \"\", \"\"); return 0; }"
1331    macos_signposts_usable)
1332  if(macos_signposts_usable)
1333    set(LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS "WITH_ASSERTS" CACHE STRING
1334        "Enable support for Xcode signposts. Can be WITH_ASSERTS, FORCE_ON, FORCE_OFF")
1335    string(TOUPPER "${LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS}"
1336                   uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS)
1337    if( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "WITH_ASSERTS" )
1338      if( LLVM_ENABLE_ASSERTIONS )
1339        set( LLVM_SUPPORT_XCODE_SIGNPOSTS 1 )
1340      endif()
1341    elseif( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "FORCE_ON" )
1342      set( LLVM_SUPPORT_XCODE_SIGNPOSTS 1 )
1343    elseif( uppercase_LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS STREQUAL "FORCE_OFF" )
1344      # We don't need to do anything special to turn off signposts.
1345    elseif( NOT DEFINED LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS )
1346      # Treat LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS like "FORCE_OFF" when it has not been
1347      # defined.
1348    else()
1349      message(FATAL_ERROR "Unknown value for LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS:"
1350                          " \"${LLVM_ENABLE_SUPPORT_XCODE_SIGNPOSTS}\"!")
1351    endif()
1352  endif()
1353endif()
1354
1355set(LLVM_SOURCE_PREFIX "" CACHE STRING "Use prefix for sources")
1356
1357option(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO "Use relative paths in debug info" OFF)
1358
1359if(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO)
1360  check_c_compiler_flag("-fdebug-prefix-map=foo=bar" SUPPORTS_FDEBUG_PREFIX_MAP)
1361  if(LLVM_ENABLE_PROJECTS_USED)
1362    get_filename_component(source_root "${LLVM_MAIN_SRC_DIR}/.." ABSOLUTE)
1363  else()
1364    set(source_root "${LLVM_MAIN_SRC_DIR}")
1365  endif()
1366  file(RELATIVE_PATH relative_root "${CMAKE_BINARY_DIR}" "${source_root}")
1367  append_if(SUPPORTS_FDEBUG_PREFIX_MAP "-fdebug-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1368  append_if(SUPPORTS_FDEBUG_PREFIX_MAP "-fdebug-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1369  if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
1370    append("-no-canonical-prefixes" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1371  endif()
1372endif()
1373
1374option(LLVM_USE_RELATIVE_PATHS_IN_FILES "Use relative paths in sources and debug info" OFF)
1375
1376if(LLVM_USE_RELATIVE_PATHS_IN_FILES)
1377  check_c_compiler_flag("-ffile-prefix-map=foo=bar" SUPPORTS_FFILE_PREFIX_MAP)
1378  if(LLVM_ENABLE_PROJECTS_USED)
1379    get_filename_component(source_root "${LLVM_MAIN_SRC_DIR}/.." ABSOLUTE)
1380  else()
1381    set(source_root "${LLVM_MAIN_SRC_DIR}")
1382  endif()
1383  file(RELATIVE_PATH relative_root "${CMAKE_BINARY_DIR}" "${source_root}")
1384  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1385  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1386  if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
1387    append("-no-canonical-prefixes" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
1388  endif()
1389endif()
1390
1391set(LLVM_THIRD_PARTY_DIR  ${CMAKE_CURRENT_SOURCE_DIR}/../third-party CACHE STRING
1392    "Directory containing third party software used by LLVM (e.g. googletest)")
1393
1394set(LLVM_UNITTEST_LINK_FLAGS "" CACHE STRING
1395    "Additional linker flags for unit tests")
1396
1397if(LLVM_ENABLE_LLVM_LIBC)
1398  check_library_exists(llvmlibc printf "" HAVE_LLVM_LIBC)
1399  if(NOT HAVE_LLVM_LIBC)
1400    message(WARNING "Unable to link against LLVM libc. LLVM will be built without linking against the LLVM libc overlay.")
1401  endif()
1402endif()
1403