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)
20include(AbseilInstallDirs)
21
22# The IDE folder for Abseil that will be used if Abseil is included in a CMake
23# project that sets
24#    set_property(GLOBAL PROPERTY USE_FOLDERS ON)
25# For example, Visual Studio supports folders.
26set(ABSL_IDE_FOLDER Abseil)
27
28# absl_cc_library()
29#
30# CMake function to imitate Bazel's cc_library rule.
31#
32# Parameters:
33# NAME: name of target (see Note)
34# HDRS: List of public header files for the library
35# SRCS: List of source files for the library
36# DEPS: List of other libraries to be linked in to the binary targets
37# COPTS: List of private compile options
38# DEFINES: List of public defines
39# LINKOPTS: List of link options
40# PUBLIC: Add this so that this library will be exported under absl::
41# Also in IDE, target will appear in Abseil folder while non PUBLIC will be in Abseil/internal.
42# TESTONLY: When added, this target will only be built if user passes -DABSL_RUN_TESTS=ON to CMake.
43#
44# Note:
45# By default, absl_cc_library will always create a library named absl_${NAME},
46# and alias target absl::${NAME}.  The absl:: form should always be used.
47# This is to reduce namespace pollution.
48#
49# absl_cc_library(
50#   NAME
51#     awesome
52#   HDRS
53#     "a.h"
54#   SRCS
55#     "a.cc"
56# )
57# absl_cc_library(
58#   NAME
59#     fantastic_lib
60#   SRCS
61#     "b.cc"
62#   DEPS
63#     absl::awesome # not "awesome" !
64#   PUBLIC
65# )
66#
67# absl_cc_library(
68#   NAME
69#     main_lib
70#   ...
71#   DEPS
72#     absl::fantastic_lib
73# )
74#
75# TODO: Implement "ALWAYSLINK"
76function(absl_cc_library)
77  cmake_parse_arguments(ABSL_CC_LIB
78    "DISABLE_INSTALL;PUBLIC;TESTONLY"
79    "NAME"
80    "HDRS;SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
81    ${ARGN}
82  )
83
84  if(ABSL_CC_LIB_TESTONLY AND NOT ABSL_RUN_TESTS)
85    return()
86  endif()
87
88  if(ABSL_ENABLE_INSTALL)
89    set(_NAME "${ABSL_CC_LIB_NAME}")
90  else()
91    set(_NAME "absl_${ABSL_CC_LIB_NAME}")
92  endif()
93
94  # Check if this is a header-only library
95  # Note that as of February 2019, many popular OS's (for example, Ubuntu
96  # 16.04 LTS) only come with cmake 3.5 by default.  For this reason, we can't
97  # use list(FILTER...)
98  set(ABSL_CC_SRCS "${ABSL_CC_LIB_SRCS}")
99  foreach(src_file IN LISTS ABSL_CC_SRCS)
100    if(${src_file} MATCHES ".*\\.(h|inc)")
101      list(REMOVE_ITEM ABSL_CC_SRCS "${src_file}")
102    endif()
103  endforeach()
104
105  if("${ABSL_CC_SRCS}" STREQUAL "")
106    set(ABSL_CC_LIB_IS_INTERFACE 1)
107  else()
108    set(ABSL_CC_LIB_IS_INTERFACE 0)
109  endif()
110
111  # Determine this build target's relationship to the DLL. It's one of four things:
112  # 1. "dll"     -- This target is part of the DLL
113  # 2. "dll_dep" -- This target is not part of the DLL, but depends on the DLL.
114  #                 Note that we assume any target not in the DLL depends on the
115  #                 DLL. This is not a technical necessity but a convenience
116  #                 which happens to be true, because nearly every target is
117  #                 part of the DLL.
118  # 3. "shared"  -- This is a shared library, perhaps on a non-windows platform
119  #                 where DLL doesn't make sense.
120  # 4. "static"  -- This target does not depend on the DLL and should be built
121  #                 statically.
122  if (${ABSL_BUILD_DLL})
123    absl_internal_dll_contains(TARGET ${_NAME} OUTPUT _in_dll)
124    if (${_in_dll})
125      # This target should be replaced by the DLL
126      set(_build_type "dll")
127      set(ABSL_CC_LIB_IS_INTERFACE 1)
128    else()
129      # Building a DLL, but this target is not part of the DLL
130      set(_build_type "dll_dep")
131    endif()
132  elseif(BUILD_SHARED_LIBS)
133    set(_build_type "shared")
134  else()
135    set(_build_type "static")
136  endif()
137
138  if(NOT ABSL_CC_LIB_IS_INTERFACE)
139    if(${_build_type} STREQUAL "dll_dep")
140      # This target depends on the DLL. When adding dependencies to this target,
141      # any depended-on-target which is contained inside the DLL is replaced
142      # with a dependency on the DLL.
143      add_library(${_NAME} STATIC "")
144      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
145      absl_internal_dll_targets(
146        DEPS ${ABSL_CC_LIB_DEPS}
147        OUTPUT _dll_deps
148      )
149      target_link_libraries(${_NAME}
150        PUBLIC ${_dll_deps}
151        PRIVATE
152          ${ABSL_CC_LIB_LINKOPTS}
153          ${ABSL_DEFAULT_LINKOPTS}
154      )
155
156      if (ABSL_CC_LIB_TESTONLY)
157        set(_gtest_link_define "GTEST_LINKED_AS_SHARED_LIBRARY=1")
158      else()
159        set(_gtest_link_define)
160      endif()
161
162      target_compile_definitions(${_NAME}
163        PUBLIC
164          ABSL_CONSUME_DLL
165          "${_gtest_link_define}"
166      )
167
168    elseif(${_build_type} STREQUAL "static" OR ${_build_type} STREQUAL "shared")
169      add_library(${_NAME} "")
170      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
171      target_link_libraries(${_NAME}
172      PUBLIC ${ABSL_CC_LIB_DEPS}
173      PRIVATE
174        ${ABSL_CC_LIB_LINKOPTS}
175        ${ABSL_DEFAULT_LINKOPTS}
176      )
177    else()
178      message(FATAL_ERROR "Invalid build type: ${_build_type}")
179    endif()
180
181    # Linker language can be inferred from sources, but in the case of DLLs we
182    # don't have any .cc files so it would be ambiguous. We could set it
183    # explicitly only in the case of DLLs but, because "CXX" is always the
184    # correct linker language for static or for shared libraries, we set it
185    # unconditionally.
186    set_property(TARGET ${_NAME} PROPERTY LINKER_LANGUAGE "CXX")
187
188    target_include_directories(${_NAME}
189      PUBLIC
190        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
191        $<INSTALL_INTERFACE:${ABSL_INSTALL_INCLUDEDIR}>
192    )
193    target_compile_options(${_NAME}
194      PRIVATE ${ABSL_CC_LIB_COPTS})
195    target_compile_definitions(${_NAME} PUBLIC ${ABSL_CC_LIB_DEFINES})
196
197    # Add all Abseil targets to a a folder in the IDE for organization.
198    if(ABSL_CC_LIB_PUBLIC)
199      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER})
200    elseif(ABSL_CC_LIB_TESTONLY)
201      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
202    else()
203      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/internal)
204    endif()
205
206    # INTERFACE libraries can't have the CXX_STANDARD property set
207    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
208    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
209
210    # When being installed, we lose the absl_ prefix.  We want to put it back
211    # to have properly named lib files.  This is a no-op when we are not being
212    # installed.
213    if(ABSL_ENABLE_INSTALL)
214      set_target_properties(${_NAME} PROPERTIES
215        OUTPUT_NAME "absl_${_NAME}"
216      )
217    endif()
218  else()
219    # Generating header-only library
220    add_library(${_NAME} INTERFACE)
221    target_include_directories(${_NAME}
222      INTERFACE
223        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
224        $<INSTALL_INTERFACE:${ABSL_INSTALL_INCLUDEDIR}>
225      )
226
227    if (${_build_type} STREQUAL "dll")
228        set(ABSL_CC_LIB_DEPS abseil_dll)
229    endif()
230
231    target_link_libraries(${_NAME}
232      INTERFACE
233        ${ABSL_CC_LIB_DEPS}
234        ${ABSL_CC_LIB_LINKOPTS}
235        ${ABSL_DEFAULT_LINKOPTS}
236    )
237    target_compile_definitions(${_NAME} INTERFACE ${ABSL_CC_LIB_DEFINES})
238  endif()
239
240  # TODO currently we don't install googletest alongside abseil sources, so
241  # installed abseil can't be tested.
242  if(NOT ABSL_CC_LIB_TESTONLY AND ABSL_ENABLE_INSTALL)
243    install(TARGETS ${_NAME} EXPORT ${PROJECT_NAME}Targets
244          RUNTIME DESTINATION ${ABSL_INSTALL_BINDIR}
245          LIBRARY DESTINATION ${ABSL_INSTALL_LIBDIR}
246          ARCHIVE DESTINATION ${ABSL_INSTALL_LIBDIR}
247    )
248  endif()
249
250    add_library(absl::${ABSL_CC_LIB_NAME} ALIAS ${_NAME})
251endfunction()
252
253# absl_cc_test()
254#
255# CMake function to imitate Bazel's cc_test rule.
256#
257# Parameters:
258# NAME: name of target (see Usage below)
259# SRCS: List of source files for the binary
260# DEPS: List of other libraries to be linked in to the binary targets
261# COPTS: List of private compile options
262# DEFINES: List of public defines
263# LINKOPTS: List of link options
264#
265# Note:
266# By default, absl_cc_test will always create a binary named absl_${NAME}.
267# This will also add it to ctest list as absl_${NAME}.
268#
269# Usage:
270# absl_cc_library(
271#   NAME
272#     awesome
273#   HDRS
274#     "a.h"
275#   SRCS
276#     "a.cc"
277#   PUBLIC
278# )
279#
280# absl_cc_test(
281#   NAME
282#     awesome_test
283#   SRCS
284#     "awesome_test.cc"
285#   DEPS
286#     absl::awesome
287#     gmock
288#     gtest_main
289# )
290function(absl_cc_test)
291  if(NOT ABSL_RUN_TESTS)
292    return()
293  endif()
294
295  cmake_parse_arguments(ABSL_CC_TEST
296    ""
297    "NAME"
298    "SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
299    ${ARGN}
300  )
301
302  set(_NAME "absl_${ABSL_CC_TEST_NAME}")
303
304  add_executable(${_NAME} "")
305  target_sources(${_NAME} PRIVATE ${ABSL_CC_TEST_SRCS})
306  target_include_directories(${_NAME}
307    PUBLIC ${ABSL_COMMON_INCLUDE_DIRS}
308    PRIVATE ${GMOCK_INCLUDE_DIRS} ${GTEST_INCLUDE_DIRS}
309  )
310
311  if (${ABSL_BUILD_DLL})
312    target_compile_definitions(${_NAME}
313      PUBLIC
314        ${ABSL_CC_TEST_DEFINES}
315        ABSL_CONSUME_DLL
316        GTEST_LINKED_AS_SHARED_LIBRARY=1
317    )
318
319    # Replace dependencies on targets inside the DLL with abseil_dll itself.
320    absl_internal_dll_targets(
321      DEPS ${ABSL_CC_TEST_DEPS}
322      OUTPUT ABSL_CC_TEST_DEPS
323    )
324  else()
325    target_compile_definitions(${_NAME}
326      PUBLIC
327        ${ABSL_CC_TEST_DEFINES}
328    )
329  endif()
330  target_compile_options(${_NAME}
331    PRIVATE ${ABSL_CC_TEST_COPTS}
332  )
333
334  target_link_libraries(${_NAME}
335    PUBLIC ${ABSL_CC_TEST_DEPS}
336    PRIVATE ${ABSL_CC_TEST_LINKOPTS}
337  )
338  # Add all Abseil targets to a folder in the IDE for organization.
339  set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
340
341  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
342  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
343
344  add_test(NAME ${_NAME} COMMAND ${_NAME})
345endfunction()
346
347
348function(check_target my_target)
349  if(NOT TARGET ${my_target})
350    message(FATAL_ERROR " ABSL: compiling absl requires a ${my_target} CMake target in your project,
351                   see CMake/README.md for more details")
352  endif(NOT TARGET ${my_target})
353endfunction()
354