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
5include(AddLLVMDefinitions)
6include(CheckCCompilerFlag)
7include(CheckCXXCompilerFlag)
8
9if( CMAKE_COMPILER_IS_GNUCXX )
10  set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
11elseif( MSVC )
12  set(LLVM_COMPILER_IS_GCC_COMPATIBLE OFF)
13elseif( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
14  set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
15endif()
16
17if( LLVM_ENABLE_ASSERTIONS )
18  # MSVC doesn't like _DEBUG on release builds. See PR 4379.
19  if( NOT MSVC )
20    add_definitions( -D_DEBUG )
21  endif()
22  # On non-Debug builds cmake automatically defines NDEBUG, so we
23  # explicitly undefine it:
24  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
25    add_definitions( -UNDEBUG )
26    # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
27    set(REGEXP_NDEBUG "(^| )[/-]D *NDEBUG($| )")
28    string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
29      CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
30    string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
31      CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
32    string (REGEX REPLACE "${REGEXP_NDEBUG}" " "
33      CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL}")
34  endif()
35else()
36  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" )
37    if( NOT MSVC_IDE AND NOT XCODE )
38      add_definitions( -DNDEBUG )
39    endif()
40  endif()
41endif()
42
43if(WIN32)
44  if(CYGWIN)
45    set(LLVM_ON_WIN32 0)
46    set(LLVM_ON_UNIX 1)
47  else(CYGWIN)
48    set(LLVM_ON_WIN32 1)
49    set(LLVM_ON_UNIX 0)
50  endif(CYGWIN)
51  set(LTDL_SHLIB_EXT ".dll")
52  set(EXEEXT ".exe")
53  # Maximum path length is 160 for non-unicode paths
54  set(MAXPATHLEN 160)
55else(WIN32)
56  if(UNIX)
57    set(LLVM_ON_WIN32 0)
58    set(LLVM_ON_UNIX 1)
59    if(APPLE)
60      set(LTDL_SHLIB_EXT ".dylib")
61    else(APPLE)
62      set(LTDL_SHLIB_EXT ".so")
63    endif(APPLE)
64    set(EXEEXT "")
65    # FIXME: Maximum path length is currently set to 'safe' fixed value
66    set(MAXPATHLEN 2024)
67  else(UNIX)
68    MESSAGE(SEND_ERROR "Unable to determine platform")
69  endif(UNIX)
70endif(WIN32)
71
72function(add_flag_or_print_warning flag)
73  check_c_compiler_flag(${flag} C_SUPPORTS_FLAG)
74  check_cxx_compiler_flag(${flag} CXX_SUPPORTS_FLAG)
75  if (C_SUPPORTS_FLAG AND CXX_SUPPORTS_FLAG)
76    message(STATUS "Building with ${flag}")
77    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE)
78    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE)
79  else()
80    message(WARNING "${flag} is not supported.")
81  endif()
82endfunction()
83
84function(append value)
85  foreach(variable ${ARGN})
86    set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
87  endforeach(variable)
88endfunction()
89
90function(append_if condition value)
91  if (${condition})
92    foreach(variable ${ARGN})
93      set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
94    endforeach(variable)
95  endif()
96endfunction()
97
98macro(add_flag_if_supported flag)
99  check_c_compiler_flag(${flag} C_SUPPORTS_FLAG)
100  append_if(C_SUPPORTS_FLAG "${flag}" CMAKE_C_FLAGS)
101  check_cxx_compiler_flag(${flag} CXX_SUPPORTS_FLAG)
102  append_if(CXX_SUPPORTS_FLAG "${flag}" CMAKE_CXX_FLAGS)
103endmacro()
104
105if( LLVM_ENABLE_PIC )
106  if( XCODE )
107    # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
108    # know how to disable this, so just force ENABLE_PIC off for now.
109    message(WARNING "-fPIC not supported with Xcode.")
110  elseif( WIN32 OR CYGWIN)
111    # On Windows all code is PIC. MinGW warns if -fPIC is used.
112  else()
113    add_flag_or_print_warning("-fPIC")
114
115    if( WIN32 OR CYGWIN)
116      # MinGW warns if -fvisibility-inlines-hidden is used.
117    else()
118      check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
119      append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
120    endif()
121  endif()
122endif()
123
124if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
125  # TODO: support other platforms and toolchains.
126  if( LLVM_BUILD_32_BITS )
127    message(STATUS "Building 32 bits executables and libraries.")
128    add_llvm_definitions( -m32 )
129    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
130    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
131    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
132  endif( LLVM_BUILD_32_BITS )
133endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
134
135# On Win32 using MS tools, provide an option to set the number of parallel jobs
136# to use.
137if( MSVC_IDE )
138  set(LLVM_COMPILER_JOBS "0" CACHE STRING
139    "Number of parallel compiler jobs. 0 means use all processors. Default is 0.")
140  if( NOT LLVM_COMPILER_JOBS STREQUAL "1" )
141    if( LLVM_COMPILER_JOBS STREQUAL "0" )
142      add_llvm_definitions( /MP )
143    else()
144      if (MSVC10)
145        message(FATAL_ERROR
146          "Due to a bug in CMake only 0 and 1 is supported for "
147          "LLVM_COMPILER_JOBS when generating for Visual Studio 2010")
148      else()
149        message(STATUS "Number of parallel compiler jobs set to " ${LLVM_COMPILER_JOBS})
150        add_llvm_definitions( /MP${LLVM_COMPILER_JOBS} )
151      endif()
152    endif()
153  else()
154    message(STATUS "Parallel compilation disabled")
155  endif()
156endif()
157
158if( MSVC )
159  include(ChooseMSVCCRT)
160
161  if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
162    # set stack reserved size to ~10MB
163    # CMake previously automatically set this value for MSVC builds, but the
164    # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
165    # value (1 MB) which is not enough for us in tasks such as parsing recursive
166    # C++ templates in Clang.
167    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
168  endif()
169
170  if( MSVC10 )
171    # MSVC 10 will complain about headers in the STL not being exported, but
172    # will not complain in MSVC 11.
173    add_llvm_definitions(
174      -wd4275 # Suppress 'An exported class was derived from a class that was not exported.'
175    )
176  elseif( MSVC11 )
177    add_llvm_definitions(-D_VARIADIC_MAX=10)
178  endif()
179
180  # Add definitions that make MSVC much less annoying.
181  add_llvm_definitions(
182    # For some reason MS wants to deprecate a bunch of standard functions...
183    -D_CRT_SECURE_NO_DEPRECATE
184    -D_CRT_SECURE_NO_WARNINGS
185    -D_CRT_NONSTDC_NO_DEPRECATE
186    -D_CRT_NONSTDC_NO_WARNINGS
187    -D_SCL_SECURE_NO_DEPRECATE
188    -D_SCL_SECURE_NO_WARNINGS
189
190    # Disabled warnings.
191    -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
192    -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
193    -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
194    -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
195    -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
196    -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
197    -wd4355 # Suppress ''this' : used in base member initializer list'
198    -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
199    -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
200    -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'
201    -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
202
203    # Promoted warnings.
204    -w14062 # Promote 'enumerator in switch of enum is not handled' to level 1 warning.
205
206    # Promoted warnings to errors.
207    -we4238 # Promote 'nonstandard extension used : class rvalue used as lvalue' to error.
208    )
209
210  # Enable warnings
211  if (LLVM_ENABLE_WARNINGS)
212    add_llvm_definitions( /W4 )
213    if (LLVM_ENABLE_PEDANTIC)
214      # No MSVC equivalent available
215    endif (LLVM_ENABLE_PEDANTIC)
216  endif (LLVM_ENABLE_WARNINGS)
217  if (LLVM_ENABLE_WERROR)
218    add_llvm_definitions( /WX )
219  endif (LLVM_ENABLE_WERROR)
220elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
221  if (LLVM_ENABLE_WARNINGS)
222    append("-Wall -W -Wno-unused-parameter -Wwrite-strings" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
223
224    # Turn off missing field initializer warnings for gcc to avoid noise from
225    # false positives with empty {}. Turn them on otherwise (they're off by
226    # default for clang).
227    check_cxx_compiler_flag("-Wmissing-field-initializers" CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
228    if (CXX_SUPPORTS_MISSING_FIELD_INITIALIZERS_FLAG)
229      if (CMAKE_COMPILER_IS_GNUCXX)
230        append("-Wno-missing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
231      else()
232        append("-Wmissing-field-initializers" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
233      endif()
234    endif()
235
236    append_if(LLVM_ENABLE_PEDANTIC "-pedantic -Wno-long-long" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
237    check_cxx_compiler_flag("-Werror -Wcovered-switch-default" CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
238    append_if(CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG "-Wcovered-switch-default" CMAKE_CXX_FLAGS)
239    check_c_compiler_flag("-Werror -Wcovered-switch-default" C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
240    append_if(C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG "-Wcovered-switch-default" CMAKE_C_FLAGS)
241    append_if(USE_NO_UNINITIALIZED "-Wno-uninitialized" CMAKE_CXX_FLAGS)
242    append_if(USE_NO_MAYBE_UNINITIALIZED "-Wno-maybe-uninitialized" CMAKE_CXX_FLAGS)
243    check_cxx_compiler_flag("-Werror -Wnon-virtual-dtor" CXX_SUPPORTS_NON_VIRTUAL_DTOR_FLAG)
244    append_if(CXX_SUPPORTS_NON_VIRTUAL_DTOR_FLAG "-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
245  endif (LLVM_ENABLE_WARNINGS)
246  if (LLVM_ENABLE_WERROR)
247    add_llvm_definitions( -Werror )
248  endif (LLVM_ENABLE_WERROR)
249endif( MSVC )
250
251macro(append_common_sanitizer_flags)
252  # Append -fno-omit-frame-pointer and turn on debug info to get better
253  # stack traces.
254  add_flag_if_supported("-fno-omit-frame-pointer")
255  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
256      NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
257    add_flag_if_supported("-gline-tables-only")
258  endif()
259  # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
260  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
261    add_flag_if_supported("-O1")
262  endif()
263endmacro()
264
265# Turn on sanitizers if necessary.
266if(LLVM_USE_SANITIZER)
267  if (LLVM_ON_UNIX)
268    if (LLVM_USE_SANITIZER STREQUAL "Address")
269      append_common_sanitizer_flags()
270      add_flag_or_print_warning("-fsanitize=address")
271    elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
272      append_common_sanitizer_flags()
273      add_flag_or_print_warning("-fsanitize=memory")
274      if(LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
275        add_flag_or_print_warning("-fsanitize-memory-track-origins")
276      endif()
277    else()
278      message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
279    endif()
280  else()
281    message(WARNING "LLVM_USE_SANITIZER is not supported on this platform.")
282  endif()
283endif()
284
285# Turn on -gsplit-dwarf if requested
286if(LLVM_USE_SPLIT_DWARF)
287  add_llvm_definitions("-gsplit-dwarf")
288endif()
289
290add_llvm_definitions( -D__STDC_CONSTANT_MACROS )
291add_llvm_definitions( -D__STDC_FORMAT_MACROS )
292add_llvm_definitions( -D__STDC_LIMIT_MACROS )
293
294# clang doesn't print colored diagnostics when invoked from Ninja
295if (UNIX AND
296    CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
297    CMAKE_GENERATOR STREQUAL "Ninja")
298  append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
299endif()
300