1#
2# Copyright 2017 The Abseil Authors.
3#
4# Licensed under the Apache License, Version 2.0 (the "License");
5# you may not use this file except in compliance with the License.
6# You may obtain a copy of the License at
7#
8#    https://www.apache.org/licenses/LICENSE-2.0
9#
10# Unless required by applicable law or agreed to in writing, software
11# distributed under the License is distributed on an "AS IS" BASIS,
12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13# See the License for the specific language governing permissions and
14# limitations under the License.
15#
16
17include(CMakeParseArguments)
18include(AbseilConfigureCopts)
19include(AbseilDll)
20
21# The IDE folder for Abseil that will be used if Abseil is included in a CMake
22# project that sets
23#    set_property(GLOBAL PROPERTY USE_FOLDERS ON)
24# For example, Visual Studio supports folders.
25if(NOT DEFINED ABSL_IDE_FOLDER)
26  set(ABSL_IDE_FOLDER Abseil)
27endif()
28
29if(ABSL_USE_SYSTEM_INCLUDES)
30  set(ABSL_INTERNAL_INCLUDE_WARNING_GUARD SYSTEM)
31else()
32  set(ABSL_INTERNAL_INCLUDE_WARNING_GUARD "")
33endif()
34
35# absl_cc_library()
36#
37# CMake function to imitate Bazel's cc_library rule.
38#
39# Parameters:
40# NAME: name of target (see Note)
41# HDRS: List of public header files for the library
42# SRCS: List of source files for the library
43# DEPS: List of other libraries to be linked in to the binary targets
44# COPTS: List of private compile options
45# DEFINES: List of public defines
46# LINKOPTS: List of link options
47# PUBLIC: Add this so that this library will be exported under absl::
48# Also in IDE, target will appear in Abseil folder while non PUBLIC will be in Abseil/internal.
49# TESTONLY: When added, this target will only be built if both
50#           BUILD_TESTING=ON and ABSL_BUILD_TESTING=ON.
51#
52# Note:
53# By default, absl_cc_library will always create a library named absl_${NAME},
54# and alias target absl::${NAME}.  The absl:: form should always be used.
55# This is to reduce namespace pollution.
56#
57# absl_cc_library(
58#   NAME
59#     awesome
60#   HDRS
61#     "a.h"
62#   SRCS
63#     "a.cc"
64# )
65# absl_cc_library(
66#   NAME
67#     fantastic_lib
68#   SRCS
69#     "b.cc"
70#   DEPS
71#     absl::awesome # not "awesome" !
72#   PUBLIC
73# )
74#
75# absl_cc_library(
76#   NAME
77#     main_lib
78#   ...
79#   DEPS
80#     absl::fantastic_lib
81# )
82#
83# TODO: Implement "ALWAYSLINK"
84function(absl_cc_library)
85  cmake_parse_arguments(ABSL_CC_LIB
86    "DISABLE_INSTALL;PUBLIC;TESTONLY"
87    "NAME"
88    "HDRS;SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
89    ${ARGN}
90  )
91
92  if(ABSL_CC_LIB_TESTONLY AND
93      NOT ((BUILD_TESTING AND ABSL_BUILD_TESTING) OR
94        (ABSL_BUILD_TEST_HELPERS AND ABSL_CC_LIB_PUBLIC)))
95    return()
96  endif()
97
98  if(ABSL_ENABLE_INSTALL)
99    set(_NAME "${ABSL_CC_LIB_NAME}")
100  else()
101    set(_NAME "absl_${ABSL_CC_LIB_NAME}")
102  endif()
103
104  # Check if this is a header-only library
105  # Note that as of February 2019, many popular OS's (for example, Ubuntu
106  # 16.04 LTS) only come with cmake 3.5 by default.  For this reason, we can't
107  # use list(FILTER...)
108  set(ABSL_CC_SRCS "${ABSL_CC_LIB_SRCS}")
109  foreach(src_file IN LISTS ABSL_CC_SRCS)
110    if(${src_file} MATCHES ".*\\.(h|inc)")
111      list(REMOVE_ITEM ABSL_CC_SRCS "${src_file}")
112    endif()
113  endforeach()
114
115  if(ABSL_CC_SRCS STREQUAL "")
116    set(ABSL_CC_LIB_IS_INTERFACE 1)
117  else()
118    set(ABSL_CC_LIB_IS_INTERFACE 0)
119  endif()
120
121  # Determine this build target's relationship to the DLL. It's one of four things:
122  # 1. "dll"     -- This target is part of the DLL
123  # 2. "dll_dep" -- This target is not part of the DLL, but depends on the DLL.
124  #                 Note that we assume any target not in the DLL depends on the
125  #                 DLL. This is not a technical necessity but a convenience
126  #                 which happens to be true, because nearly every target is
127  #                 part of the DLL.
128  # 3. "shared"  -- This is a shared library, perhaps on a non-windows platform
129  #                 where DLL doesn't make sense.
130  # 4. "static"  -- This target does not depend on the DLL and should be built
131  #                 statically.
132  if (${ABSL_BUILD_DLL})
133    if(ABSL_ENABLE_INSTALL)
134      absl_internal_dll_contains(TARGET ${_NAME} OUTPUT _in_dll)
135      absl_internal_test_dll_contains(TARGET ${_NAME} OUTPUT _in_test_dll)
136    else()
137      absl_internal_dll_contains(TARGET ${ABSL_CC_LIB_NAME} OUTPUT _in_dll)
138      absl_internal_test_dll_contains(TARGET ${ABSL_CC_LIB_NAME} OUTPUT _in_test_dll)
139    endif()
140    if (${_in_dll} OR ${_in_test_dll})
141      # This target should be replaced by the DLL
142      set(_build_type "dll")
143      set(ABSL_CC_LIB_IS_INTERFACE 1)
144    else()
145      # Building a DLL, but this target is not part of the DLL
146      set(_build_type "dll_dep")
147    endif()
148  elseif(BUILD_SHARED_LIBS)
149    set(_build_type "shared")
150  else()
151    set(_build_type "static")
152  endif()
153
154  # Generate a pkg-config file for every library:
155  if(ABSL_ENABLE_INSTALL)
156    if(NOT ABSL_CC_LIB_TESTONLY)
157      if(absl_VERSION)
158        set(PC_VERSION "${absl_VERSION}")
159      else()
160        set(PC_VERSION "head")
161      endif()
162      if(NOT _build_type STREQUAL "dll")
163        set(LNK_LIB "${LNK_LIB} -labsl_${_NAME}")
164      endif()
165      foreach(dep ${ABSL_CC_LIB_DEPS})
166        if(${dep} MATCHES "^absl::(.*)")
167          # for DLL builds many libs are not created, but add
168          # the pkgconfigs nevertheless, pointing to the dll.
169          if(_build_type STREQUAL "dll")
170            # hide this MATCHES in an if-clause so it doesn't overwrite
171            # the CMAKE_MATCH_1 from (${dep} MATCHES "^absl::(.*)")
172            if(NOT PC_DEPS MATCHES "abseil_dll")
173              # Join deps with commas.
174              if(PC_DEPS)
175                set(PC_DEPS "${PC_DEPS},")
176              endif()
177              # don't duplicate dll-dep if it exists already
178              set(PC_DEPS "${PC_DEPS} abseil_dll = ${PC_VERSION}")
179              set(LNK_LIB "${LNK_LIB} -labseil_dll")
180            endif()
181          else()
182            # Join deps with commas.
183            if(PC_DEPS)
184              set(PC_DEPS "${PC_DEPS},")
185            endif()
186            set(PC_DEPS "${PC_DEPS} absl_${CMAKE_MATCH_1} = ${PC_VERSION}")
187          endif()
188        endif()
189      endforeach()
190      foreach(cflag ${ABSL_CC_LIB_COPTS})
191        if(${cflag} MATCHES "^(-Wno|/wd)")
192          # These flags are needed to suppress warnings that might fire in our headers.
193          set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
194        elseif(${cflag} MATCHES "^(-W|/w[1234eo])")
195          # Don't impose our warnings on others.
196        elseif(${cflag} MATCHES "^-m")
197          # Don't impose CPU instruction requirements on others, as
198          # the code performs feature detection on runtime.
199        else()
200          set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
201        endif()
202      endforeach()
203      string(REPLACE ";" " " PC_LINKOPTS "${ABSL_CC_LIB_LINKOPTS}")
204      FILE(GENERATE OUTPUT "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc" CONTENT "\
205prefix=${CMAKE_INSTALL_PREFIX}\n\
206exec_prefix=\${prefix}\n\
207libdir=${CMAKE_INSTALL_FULL_LIBDIR}\n\
208includedir=${CMAKE_INSTALL_FULL_INCLUDEDIR}\n\
209\n\
210Name: absl_${_NAME}\n\
211Description: Abseil ${_NAME} library\n\
212URL: https://abseil.io/\n\
213Version: ${PC_VERSION}\n\
214Requires:${PC_DEPS}\n\
215Libs: -L\${libdir} ${PC_LINKOPTS} $<$<NOT:$<BOOL:${ABSL_CC_LIB_IS_INTERFACE}>>:${LNK_LIB}>\n\
216Cflags: -I\${includedir}${PC_CFLAGS}\n")
217      INSTALL(FILES "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc"
218              DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
219    endif()
220  endif()
221
222  if(NOT ABSL_CC_LIB_IS_INTERFACE)
223    if(_build_type STREQUAL "dll_dep")
224      # This target depends on the DLL. When adding dependencies to this target,
225      # any depended-on-target which is contained inside the DLL is replaced
226      # with a dependency on the DLL.
227      add_library(${_NAME} STATIC "")
228      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
229      absl_internal_dll_targets(
230        DEPS ${ABSL_CC_LIB_DEPS}
231        OUTPUT _dll_deps
232      )
233      target_link_libraries(${_NAME}
234        PUBLIC ${_dll_deps}
235        PRIVATE
236          ${ABSL_CC_LIB_LINKOPTS}
237          ${ABSL_DEFAULT_LINKOPTS}
238      )
239
240      if (ABSL_CC_LIB_TESTONLY)
241        set(_gtest_link_define "GTEST_LINKED_AS_SHARED_LIBRARY=1")
242      else()
243        set(_gtest_link_define)
244      endif()
245
246      target_compile_definitions(${_NAME}
247        PUBLIC
248          ABSL_CONSUME_DLL
249          "${_gtest_link_define}"
250      )
251
252    elseif(_build_type STREQUAL "static" OR _build_type STREQUAL "shared")
253      add_library(${_NAME} "")
254      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
255      target_link_libraries(${_NAME}
256      PUBLIC ${ABSL_CC_LIB_DEPS}
257      PRIVATE
258        ${ABSL_CC_LIB_LINKOPTS}
259        ${ABSL_DEFAULT_LINKOPTS}
260      )
261    else()
262      message(FATAL_ERROR "Invalid build type: ${_build_type}")
263    endif()
264
265    # Linker language can be inferred from sources, but in the case of DLLs we
266    # don't have any .cc files so it would be ambiguous. We could set it
267    # explicitly only in the case of DLLs but, because "CXX" is always the
268    # correct linker language for static or for shared libraries, we set it
269    # unconditionally.
270    set_property(TARGET ${_NAME} PROPERTY LINKER_LANGUAGE "CXX")
271
272    target_include_directories(${_NAME} ${ABSL_INTERNAL_INCLUDE_WARNING_GUARD}
273      PUBLIC
274        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
275        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
276    )
277    target_compile_options(${_NAME}
278      PRIVATE ${ABSL_CC_LIB_COPTS})
279    target_compile_definitions(${_NAME} PUBLIC ${ABSL_CC_LIB_DEFINES})
280
281    # Add all Abseil targets to a a folder in the IDE for organization.
282    if(ABSL_CC_LIB_PUBLIC)
283      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER})
284    elseif(ABSL_CC_LIB_TESTONLY)
285      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
286    else()
287      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/internal)
288    endif()
289
290    if(ABSL_PROPAGATE_CXX_STD)
291      # Abseil libraries require C++14 as the current minimum standard. When
292      # compiled with C++17 (either because it is the compiler's default or
293      # explicitly requested), then Abseil requires C++17.
294      _absl_target_compile_features_if_available(${_NAME} PUBLIC ${ABSL_INTERNAL_CXX_STD_FEATURE})
295    else()
296      # Note: This is legacy (before CMake 3.8) behavior. Setting the
297      # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
298      # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
299      # that is the default value anyway.
300      #
301      # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
302      # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
303      # "decaying" to an older standard if the requested one isn't available).
304      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
305      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
306    endif()
307
308    # When being installed, we lose the absl_ prefix.  We want to put it back
309    # to have properly named lib files.  This is a no-op when we are not being
310    # installed.
311    if(ABSL_ENABLE_INSTALL)
312      set_target_properties(${_NAME} PROPERTIES
313        OUTPUT_NAME "absl_${_NAME}"
314        SOVERSION "2301.0.0"
315      )
316    endif()
317  else()
318    # Generating header-only library
319    add_library(${_NAME} INTERFACE)
320    target_include_directories(${_NAME} ${ABSL_INTERNAL_INCLUDE_WARNING_GUARD}
321      INTERFACE
322        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
323        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
324      )
325
326    if (_build_type STREQUAL "dll")
327        set(ABSL_CC_LIB_DEPS abseil_dll)
328    endif()
329
330    target_link_libraries(${_NAME}
331      INTERFACE
332        ${ABSL_CC_LIB_DEPS}
333        ${ABSL_CC_LIB_LINKOPTS}
334        ${ABSL_DEFAULT_LINKOPTS}
335    )
336    target_compile_definitions(${_NAME} INTERFACE ${ABSL_CC_LIB_DEFINES})
337
338    if(ABSL_PROPAGATE_CXX_STD)
339      # Abseil libraries require C++14 as the current minimum standard.
340      # Top-level application CMake projects should ensure a consistent C++
341      # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
342      _absl_target_compile_features_if_available(${_NAME} INTERFACE ${ABSL_INTERNAL_CXX_STD_FEATURE})
343
344      # (INTERFACE libraries can't have the CXX_STANDARD property set, so there
345      # is no legacy behavior else case).
346    endif()
347  endif()
348
349  # TODO currently we don't install googletest alongside abseil sources, so
350  # installed abseil can't be tested.
351  if(NOT ABSL_CC_LIB_TESTONLY AND ABSL_ENABLE_INSTALL)
352    install(TARGETS ${_NAME} EXPORT ${PROJECT_NAME}Targets
353          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
354          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
355          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
356    )
357  endif()
358
359    add_library(absl::${ABSL_CC_LIB_NAME} ALIAS ${_NAME})
360endfunction()
361
362# absl_cc_test()
363#
364# CMake function to imitate Bazel's cc_test rule.
365#
366# Parameters:
367# NAME: name of target (see Usage below)
368# SRCS: List of source files for the binary
369# DEPS: List of other libraries to be linked in to the binary targets
370# COPTS: List of private compile options
371# DEFINES: List of public defines
372# LINKOPTS: List of link options
373#
374# Note:
375# By default, absl_cc_test will always create a binary named absl_${NAME}.
376# This will also add it to ctest list as absl_${NAME}.
377#
378# Usage:
379# absl_cc_library(
380#   NAME
381#     awesome
382#   HDRS
383#     "a.h"
384#   SRCS
385#     "a.cc"
386#   PUBLIC
387# )
388#
389# absl_cc_test(
390#   NAME
391#     awesome_test
392#   SRCS
393#     "awesome_test.cc"
394#   DEPS
395#     absl::awesome
396#     GTest::gmock
397#     GTest::gtest_main
398# )
399function(absl_cc_test)
400  if(NOT (BUILD_TESTING AND ABSL_BUILD_TESTING))
401    return()
402  endif()
403
404  cmake_parse_arguments(ABSL_CC_TEST
405    ""
406    "NAME"
407    "SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
408    ${ARGN}
409  )
410
411  set(_NAME "absl_${ABSL_CC_TEST_NAME}")
412
413  add_executable(${_NAME} "")
414  target_sources(${_NAME} PRIVATE ${ABSL_CC_TEST_SRCS})
415  target_include_directories(${_NAME}
416    PUBLIC ${ABSL_COMMON_INCLUDE_DIRS}
417    PRIVATE ${absl_gtest_src_dir}/googletest/include ${absl_gtest_src_dir}/googlemock/include
418  )
419
420  if (${ABSL_BUILD_DLL})
421    target_compile_definitions(${_NAME}
422      PUBLIC
423        ${ABSL_CC_TEST_DEFINES}
424        ABSL_CONSUME_DLL
425        ABSL_CONSUME_TEST_DLL
426        GTEST_LINKED_AS_SHARED_LIBRARY=1
427    )
428
429    # Replace dependencies on targets inside the DLL with abseil_dll itself.
430    absl_internal_dll_targets(
431      DEPS ${ABSL_CC_TEST_DEPS}
432      OUTPUT ABSL_CC_TEST_DEPS
433    )
434  else()
435    target_compile_definitions(${_NAME}
436      PUBLIC
437        ${ABSL_CC_TEST_DEFINES}
438    )
439  endif()
440  target_compile_options(${_NAME}
441    PRIVATE ${ABSL_CC_TEST_COPTS}
442  )
443
444  target_link_libraries(${_NAME}
445    PUBLIC ${ABSL_CC_TEST_DEPS}
446    PRIVATE ${ABSL_CC_TEST_LINKOPTS}
447  )
448  # Add all Abseil targets to a folder in the IDE for organization.
449  set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
450
451  if(ABSL_PROPAGATE_CXX_STD)
452    # Abseil libraries require C++14 as the current minimum standard.
453    # Top-level application CMake projects should ensure a consistent C++
454    # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
455    _absl_target_compile_features_if_available(${_NAME} PUBLIC ${ABSL_INTERNAL_CXX_STD_FEATURE})
456  else()
457    # Note: This is legacy (before CMake 3.8) behavior. Setting the
458    # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
459    # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
460    # that is the default value anyway.
461    #
462    # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
463    # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
464    # "decaying" to an older standard if the requested one isn't available).
465    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
466    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
467  endif()
468
469  add_test(NAME ${_NAME} COMMAND ${_NAME})
470endfunction()
471