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 ${_in_test_dll})
141      # This target should be replaced by the DLL
142      set(_build_type "dll")
143      set(ABSL_CC_LIB_IS_INTERFACE 1)
144    else()
145      # Building a DLL, but this target is not part of the DLL
146      set(_build_type "dll_dep")
147    endif()
148  elseif(BUILD_SHARED_LIBS)
149    set(_build_type "shared")
150  else()
151    set(_build_type "static")
152  endif()
153
154  # Generate a pkg-config file for every library:
155  if(ABSL_ENABLE_INSTALL)
156    if(absl_VERSION)
157      set(PC_VERSION "${absl_VERSION}")
158    else()
159      set(PC_VERSION "head")
160    endif()
161    if(NOT _build_type STREQUAL "dll")
162      set(LNK_LIB "${LNK_LIB} -labsl_${_NAME}")
163    endif()
164    foreach(dep ${ABSL_CC_LIB_DEPS})
165      if(${dep} MATCHES "^absl::(.*)")
166        # for DLL builds many libs are not created, but add
167        # the pkgconfigs nevertheless, pointing to the dll.
168        if(_build_type STREQUAL "dll")
169          # hide this MATCHES in an if-clause so it doesn't overwrite
170          # the CMAKE_MATCH_1 from (${dep} MATCHES "^absl::(.*)")
171          if(NOT PC_DEPS MATCHES "abseil_dll")
172            # Join deps with commas.
173            if(PC_DEPS)
174              set(PC_DEPS "${PC_DEPS},")
175            endif()
176            # don't duplicate dll-dep if it exists already
177            set(PC_DEPS "${PC_DEPS} abseil_dll = ${PC_VERSION}")
178            set(LNK_LIB "${LNK_LIB} -labseil_dll")
179          endif()
180        else()
181          # Join deps with commas.
182          if(PC_DEPS)
183            set(PC_DEPS "${PC_DEPS},")
184          endif()
185          set(PC_DEPS "${PC_DEPS} absl_${CMAKE_MATCH_1} = ${PC_VERSION}")
186        endif()
187      endif()
188    endforeach()
189    foreach(cflag ${ABSL_CC_LIB_COPTS})
190      if(${cflag} MATCHES "^(-Wno|/wd)")
191        # These flags are needed to suppress warnings that might fire in our headers.
192        set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
193      elseif(${cflag} MATCHES "^(-W|/w[1234eo])")
194        # Don't impose our warnings on others.
195      elseif(${cflag} MATCHES "^-m")
196        # Don't impose CPU instruction requirements on others, as
197        # the code performs feature detection on runtime.
198      else()
199        set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
200      endif()
201    endforeach()
202    string(REPLACE ";" " " PC_LINKOPTS "${ABSL_CC_LIB_LINKOPTS}")
203    FILE(GENERATE OUTPUT "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc" CONTENT "\
204prefix=${CMAKE_INSTALL_PREFIX}\n\
205exec_prefix=\${prefix}\n\
206libdir=${CMAKE_INSTALL_FULL_LIBDIR}\n\
207includedir=${CMAKE_INSTALL_FULL_INCLUDEDIR}\n\
208\n\
209Name: absl_${_NAME}\n\
210Description: Abseil ${_NAME} library\n\
211URL: https://abseil.io/\n\
212Version: ${PC_VERSION}\n\
213Requires:${PC_DEPS}\n\
214Libs: -L\${libdir} ${PC_LINKOPTS} $<$<NOT:$<BOOL:${ABSL_CC_LIB_IS_INTERFACE}>>:${LNK_LIB}>\n\
215Cflags: -I\${includedir}${PC_CFLAGS}\n")
216    INSTALL(FILES "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc"
217            DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
218  endif()
219
220  if(NOT ABSL_CC_LIB_IS_INTERFACE)
221    if(_build_type STREQUAL "dll_dep")
222      # This target depends on the DLL. When adding dependencies to this target,
223      # any depended-on-target which is contained inside the DLL is replaced
224      # with a dependency on the DLL.
225      add_library(${_NAME} STATIC "")
226      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
227      absl_internal_dll_targets(
228        DEPS ${ABSL_CC_LIB_DEPS}
229        OUTPUT _dll_deps
230      )
231      target_link_libraries(${_NAME}
232        PUBLIC ${_dll_deps}
233        PRIVATE
234          ${ABSL_CC_LIB_LINKOPTS}
235          ${ABSL_DEFAULT_LINKOPTS}
236      )
237
238      if (ABSL_CC_LIB_TESTONLY)
239        set(_gtest_link_define "GTEST_LINKED_AS_SHARED_LIBRARY=1")
240      else()
241        set(_gtest_link_define)
242      endif()
243
244      target_compile_definitions(${_NAME}
245        PUBLIC
246          ABSL_CONSUME_DLL
247          "${_gtest_link_define}"
248      )
249
250    elseif(_build_type STREQUAL "static" OR _build_type STREQUAL "shared")
251      add_library(${_NAME} "")
252      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
253      target_link_libraries(${_NAME}
254      PUBLIC ${ABSL_CC_LIB_DEPS}
255      PRIVATE
256        ${ABSL_CC_LIB_LINKOPTS}
257        ${ABSL_DEFAULT_LINKOPTS}
258      )
259    else()
260      message(FATAL_ERROR "Invalid build type: ${_build_type}")
261    endif()
262
263    # Linker language can be inferred from sources, but in the case of DLLs we
264    # don't have any .cc files so it would be ambiguous. We could set it
265    # explicitly only in the case of DLLs but, because "CXX" is always the
266    # correct linker language for static or for shared libraries, we set it
267    # unconditionally.
268    set_property(TARGET ${_NAME} PROPERTY LINKER_LANGUAGE "CXX")
269
270    target_include_directories(${_NAME} ${ABSL_INTERNAL_INCLUDE_WARNING_GUARD}
271      PUBLIC
272        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
273        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
274    )
275    target_compile_options(${_NAME}
276      PRIVATE ${ABSL_CC_LIB_COPTS})
277    target_compile_definitions(${_NAME} PUBLIC ${ABSL_CC_LIB_DEFINES})
278
279    # Add all Abseil targets to a a folder in the IDE for organization.
280    if(ABSL_CC_LIB_PUBLIC)
281      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER})
282    elseif(ABSL_CC_LIB_TESTONLY)
283      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
284    else()
285      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/internal)
286    endif()
287
288    if(ABSL_PROPAGATE_CXX_STD)
289      # Abseil libraries require C++14 as the current minimum standard. When
290      # compiled with C++17 (either because it is the compiler's default or
291      # explicitly requested), then Abseil requires C++17.
292      _absl_target_compile_features_if_available(${_NAME} PUBLIC ${ABSL_INTERNAL_CXX_STD_FEATURE})
293    else()
294      # Note: This is legacy (before CMake 3.8) behavior. Setting the
295      # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
296      # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
297      # that is the default value anyway.
298      #
299      # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
300      # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
301      # "decaying" to an older standard if the requested one isn't available).
302      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
303      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
304    endif()
305
306    # When being installed, we lose the absl_ prefix.  We want to put it back
307    # to have properly named lib files.  This is a no-op when we are not being
308    # installed.
309    if(ABSL_ENABLE_INSTALL)
310      set_target_properties(${_NAME} PROPERTIES
311        OUTPUT_NAME "absl_${_NAME}"
312        SOVERSION "2301.0.0"
313      )
314    endif()
315  else()
316    # Generating header-only library
317    add_library(${_NAME} INTERFACE)
318    target_include_directories(${_NAME} ${ABSL_INTERNAL_INCLUDE_WARNING_GUARD}
319      INTERFACE
320        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
321        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
322      )
323
324    if (_build_type STREQUAL "dll")
325        set(ABSL_CC_LIB_DEPS abseil_dll)
326    endif()
327
328    target_link_libraries(${_NAME}
329      INTERFACE
330        ${ABSL_CC_LIB_DEPS}
331        ${ABSL_CC_LIB_LINKOPTS}
332        ${ABSL_DEFAULT_LINKOPTS}
333    )
334    target_compile_definitions(${_NAME} INTERFACE ${ABSL_CC_LIB_DEFINES})
335
336    if(ABSL_PROPAGATE_CXX_STD)
337      # Abseil libraries require C++14 as the current minimum standard.
338      # Top-level application CMake projects should ensure a consistent C++
339      # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
340      _absl_target_compile_features_if_available(${_NAME} INTERFACE ${ABSL_INTERNAL_CXX_STD_FEATURE})
341
342      # (INTERFACE libraries can't have the CXX_STANDARD property set, so there
343      # is no legacy behavior else case).
344    endif()
345  endif()
346
347  if(ABSL_ENABLE_INSTALL)
348    install(TARGETS ${_NAME} EXPORT ${PROJECT_NAME}Targets
349          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
350          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
351          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
352    )
353  endif()
354
355    add_library(absl::${ABSL_CC_LIB_NAME} ALIAS ${_NAME})
356endfunction()
357
358# absl_cc_test()
359#
360# CMake function to imitate Bazel's cc_test rule.
361#
362# Parameters:
363# NAME: name of target (see Usage below)
364# SRCS: List of source files for the binary
365# DEPS: List of other libraries to be linked in to the binary targets
366# COPTS: List of private compile options
367# DEFINES: List of public defines
368# LINKOPTS: List of link options
369#
370# Note:
371# By default, absl_cc_test will always create a binary named absl_${NAME}.
372# This will also add it to ctest list as absl_${NAME}.
373#
374# Usage:
375# absl_cc_library(
376#   NAME
377#     awesome
378#   HDRS
379#     "a.h"
380#   SRCS
381#     "a.cc"
382#   PUBLIC
383# )
384#
385# absl_cc_test(
386#   NAME
387#     awesome_test
388#   SRCS
389#     "awesome_test.cc"
390#   DEPS
391#     absl::awesome
392#     GTest::gmock
393#     GTest::gtest_main
394# )
395function(absl_cc_test)
396  if(NOT (BUILD_TESTING AND ABSL_BUILD_TESTING))
397    return()
398  endif()
399
400  cmake_parse_arguments(ABSL_CC_TEST
401    ""
402    "NAME"
403    "SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
404    ${ARGN}
405  )
406
407  set(_NAME "absl_${ABSL_CC_TEST_NAME}")
408
409  add_executable(${_NAME} "")
410  target_sources(${_NAME} PRIVATE ${ABSL_CC_TEST_SRCS})
411  target_include_directories(${_NAME}
412    PUBLIC ${ABSL_COMMON_INCLUDE_DIRS}
413    PRIVATE ${absl_gtest_src_dir}/googletest/include ${absl_gtest_src_dir}/googlemock/include
414  )
415
416  if (${ABSL_BUILD_DLL})
417    target_compile_definitions(${_NAME}
418      PUBLIC
419        ${ABSL_CC_TEST_DEFINES}
420        ABSL_CONSUME_DLL
421        ABSL_CONSUME_TEST_DLL
422        GTEST_LINKED_AS_SHARED_LIBRARY=1
423    )
424
425    # Replace dependencies on targets inside the DLL with abseil_dll itself.
426    absl_internal_dll_targets(
427      DEPS ${ABSL_CC_TEST_DEPS}
428      OUTPUT ABSL_CC_TEST_DEPS
429    )
430  else()
431    target_compile_definitions(${_NAME}
432      PUBLIC
433        ${ABSL_CC_TEST_DEFINES}
434    )
435  endif()
436  target_compile_options(${_NAME}
437    PRIVATE ${ABSL_CC_TEST_COPTS}
438  )
439
440  target_link_libraries(${_NAME}
441    PUBLIC ${ABSL_CC_TEST_DEPS}
442    PRIVATE ${ABSL_CC_TEST_LINKOPTS}
443  )
444  # Add all Abseil targets to a folder in the IDE for organization.
445  set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
446
447  if(ABSL_PROPAGATE_CXX_STD)
448    # Abseil libraries require C++14 as the current minimum standard.
449    # Top-level application CMake projects should ensure a consistent C++
450    # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
451    _absl_target_compile_features_if_available(${_NAME} PUBLIC ${ABSL_INTERNAL_CXX_STD_FEATURE})
452  else()
453    # Note: This is legacy (before CMake 3.8) behavior. Setting the
454    # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
455    # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
456    # that is the default value anyway.
457    #
458    # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
459    # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
460    # "decaying" to an older standard if the requested one isn't available).
461    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
462    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
463  endif()
464
465  add_test(NAME ${_NAME} COMMAND ${_NAME})
466endfunction()
467