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.
26if(NOT DEFINED ABSL_IDE_FOLDER)
27  set(ABSL_IDE_FOLDER Abseil)
28endif()
29
30# absl_cc_library()
31#
32# CMake function to imitate Bazel's cc_library rule.
33#
34# Parameters:
35# NAME: name of target (see Note)
36# HDRS: List of public header files for the library
37# SRCS: List of source files for the library
38# DEPS: List of other libraries to be linked in to the binary targets
39# COPTS: List of private compile options
40# DEFINES: List of public defines
41# LINKOPTS: List of link options
42# PUBLIC: Add this so that this library will be exported under absl::
43# Also in IDE, target will appear in Abseil folder while non PUBLIC will be in Abseil/internal.
44# TESTONLY: When added, this target will only be built if user passes -DABSL_RUN_TESTS=ON to CMake.
45#
46# Note:
47# By default, absl_cc_library will always create a library named absl_${NAME},
48# and alias target absl::${NAME}.  The absl:: form should always be used.
49# This is to reduce namespace pollution.
50#
51# absl_cc_library(
52#   NAME
53#     awesome
54#   HDRS
55#     "a.h"
56#   SRCS
57#     "a.cc"
58# )
59# absl_cc_library(
60#   NAME
61#     fantastic_lib
62#   SRCS
63#     "b.cc"
64#   DEPS
65#     absl::awesome # not "awesome" !
66#   PUBLIC
67# )
68#
69# absl_cc_library(
70#   NAME
71#     main_lib
72#   ...
73#   DEPS
74#     absl::fantastic_lib
75# )
76#
77# TODO: Implement "ALWAYSLINK"
78function(absl_cc_library)
79  cmake_parse_arguments(ABSL_CC_LIB
80    "DISABLE_INSTALL;PUBLIC;TESTONLY"
81    "NAME"
82    "HDRS;SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
83    ${ARGN}
84  )
85
86  if(ABSL_CC_LIB_TESTONLY AND NOT ABSL_RUN_TESTS)
87    return()
88  endif()
89
90  if(ABSL_ENABLE_INSTALL)
91    set(_NAME "${ABSL_CC_LIB_NAME}")
92  else()
93    set(_NAME "absl_${ABSL_CC_LIB_NAME}")
94  endif()
95
96  # Check if this is a header-only library
97  # Note that as of February 2019, many popular OS's (for example, Ubuntu
98  # 16.04 LTS) only come with cmake 3.5 by default.  For this reason, we can't
99  # use list(FILTER...)
100  set(ABSL_CC_SRCS "${ABSL_CC_LIB_SRCS}")
101  foreach(src_file IN LISTS ABSL_CC_SRCS)
102    if(${src_file} MATCHES ".*\\.(h|inc)")
103      list(REMOVE_ITEM ABSL_CC_SRCS "${src_file}")
104    endif()
105  endforeach()
106
107  if("${ABSL_CC_SRCS}" STREQUAL "")
108    set(ABSL_CC_LIB_IS_INTERFACE 1)
109  else()
110    set(ABSL_CC_LIB_IS_INTERFACE 0)
111  endif()
112
113  # Determine this build target's relationship to the DLL. It's one of four things:
114  # 1. "dll"     -- This target is part of the DLL
115  # 2. "dll_dep" -- This target is not part of the DLL, but depends on the DLL.
116  #                 Note that we assume any target not in the DLL depends on the
117  #                 DLL. This is not a technical necessity but a convenience
118  #                 which happens to be true, because nearly every target is
119  #                 part of the DLL.
120  # 3. "shared"  -- This is a shared library, perhaps on a non-windows platform
121  #                 where DLL doesn't make sense.
122  # 4. "static"  -- This target does not depend on the DLL and should be built
123  #                 statically.
124  if (${ABSL_BUILD_DLL})
125    absl_internal_dll_contains(TARGET ${_NAME} OUTPUT _in_dll)
126    if (${_in_dll})
127      # This target should be replaced by the DLL
128      set(_build_type "dll")
129      set(ABSL_CC_LIB_IS_INTERFACE 1)
130    else()
131      # Building a DLL, but this target is not part of the DLL
132      set(_build_type "dll_dep")
133    endif()
134  elseif(BUILD_SHARED_LIBS)
135    set(_build_type "shared")
136  else()
137    set(_build_type "static")
138  endif()
139
140  if(NOT ABSL_CC_LIB_IS_INTERFACE)
141    if(${_build_type} STREQUAL "dll_dep")
142      # This target depends on the DLL. When adding dependencies to this target,
143      # any depended-on-target which is contained inside the DLL is replaced
144      # with a dependency on the DLL.
145      add_library(${_NAME} STATIC "")
146      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
147      absl_internal_dll_targets(
148        DEPS ${ABSL_CC_LIB_DEPS}
149        OUTPUT _dll_deps
150      )
151      target_link_libraries(${_NAME}
152        PUBLIC ${_dll_deps}
153        PRIVATE
154          ${ABSL_CC_LIB_LINKOPTS}
155          ${ABSL_DEFAULT_LINKOPTS}
156      )
157
158      if (ABSL_CC_LIB_TESTONLY)
159        set(_gtest_link_define "GTEST_LINKED_AS_SHARED_LIBRARY=1")
160      else()
161        set(_gtest_link_define)
162      endif()
163
164      target_compile_definitions(${_NAME}
165        PUBLIC
166          ABSL_CONSUME_DLL
167          "${_gtest_link_define}"
168      )
169
170    elseif(${_build_type} STREQUAL "static" OR ${_build_type} STREQUAL "shared")
171      add_library(${_NAME} "")
172      target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
173      target_link_libraries(${_NAME}
174      PUBLIC ${ABSL_CC_LIB_DEPS}
175      PRIVATE
176        ${ABSL_CC_LIB_LINKOPTS}
177        ${ABSL_DEFAULT_LINKOPTS}
178      )
179    else()
180      message(FATAL_ERROR "Invalid build type: ${_build_type}")
181    endif()
182
183    # Linker language can be inferred from sources, but in the case of DLLs we
184    # don't have any .cc files so it would be ambiguous. We could set it
185    # explicitly only in the case of DLLs but, because "CXX" is always the
186    # correct linker language for static or for shared libraries, we set it
187    # unconditionally.
188    set_property(TARGET ${_NAME} PROPERTY LINKER_LANGUAGE "CXX")
189
190    target_include_directories(${_NAME}
191      PUBLIC
192        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
193        $<INSTALL_INTERFACE:${ABSL_INSTALL_INCLUDEDIR}>
194    )
195    target_compile_options(${_NAME}
196      PRIVATE ${ABSL_CC_LIB_COPTS})
197    target_compile_definitions(${_NAME} PUBLIC ${ABSL_CC_LIB_DEFINES})
198
199    # Add all Abseil targets to a a folder in the IDE for organization.
200    if(ABSL_CC_LIB_PUBLIC)
201      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER})
202    elseif(ABSL_CC_LIB_TESTONLY)
203      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
204    else()
205      set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/internal)
206    endif()
207
208    # INTERFACE libraries can't have the CXX_STANDARD property set
209    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
210    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
211
212    # When being installed, we lose the absl_ prefix.  We want to put it back
213    # to have properly named lib files.  This is a no-op when we are not being
214    # installed.
215    if(ABSL_ENABLE_INSTALL)
216      set_target_properties(${_NAME} PROPERTIES
217        OUTPUT_NAME "absl_${_NAME}"
218      )
219    endif()
220  else()
221    # Generating header-only library
222    add_library(${_NAME} INTERFACE)
223    target_include_directories(${_NAME}
224      INTERFACE
225        "$<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>"
226        $<INSTALL_INTERFACE:${ABSL_INSTALL_INCLUDEDIR}>
227      )
228
229    if (${_build_type} STREQUAL "dll")
230        set(ABSL_CC_LIB_DEPS abseil_dll)
231    endif()
232
233    target_link_libraries(${_NAME}
234      INTERFACE
235        ${ABSL_CC_LIB_DEPS}
236        ${ABSL_CC_LIB_LINKOPTS}
237        ${ABSL_DEFAULT_LINKOPTS}
238    )
239    target_compile_definitions(${_NAME} INTERFACE ${ABSL_CC_LIB_DEFINES})
240  endif()
241
242  # TODO currently we don't install googletest alongside abseil sources, so
243  # installed abseil can't be tested.
244  if(NOT ABSL_CC_LIB_TESTONLY AND ABSL_ENABLE_INSTALL)
245    install(TARGETS ${_NAME} EXPORT ${PROJECT_NAME}Targets
246          RUNTIME DESTINATION ${ABSL_INSTALL_BINDIR}
247          LIBRARY DESTINATION ${ABSL_INSTALL_LIBDIR}
248          ARCHIVE DESTINATION ${ABSL_INSTALL_LIBDIR}
249    )
250  endif()
251
252    add_library(absl::${ABSL_CC_LIB_NAME} ALIAS ${_NAME})
253endfunction()
254
255# absl_cc_test()
256#
257# CMake function to imitate Bazel's cc_test rule.
258#
259# Parameters:
260# NAME: name of target (see Usage below)
261# SRCS: List of source files for the binary
262# DEPS: List of other libraries to be linked in to the binary targets
263# COPTS: List of private compile options
264# DEFINES: List of public defines
265# LINKOPTS: List of link options
266#
267# Note:
268# By default, absl_cc_test will always create a binary named absl_${NAME}.
269# This will also add it to ctest list as absl_${NAME}.
270#
271# Usage:
272# absl_cc_library(
273#   NAME
274#     awesome
275#   HDRS
276#     "a.h"
277#   SRCS
278#     "a.cc"
279#   PUBLIC
280# )
281#
282# absl_cc_test(
283#   NAME
284#     awesome_test
285#   SRCS
286#     "awesome_test.cc"
287#   DEPS
288#     absl::awesome
289#     gmock
290#     gtest_main
291# )
292function(absl_cc_test)
293  if(NOT ABSL_RUN_TESTS)
294    return()
295  endif()
296
297  cmake_parse_arguments(ABSL_CC_TEST
298    ""
299    "NAME"
300    "SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
301    ${ARGN}
302  )
303
304  set(_NAME "absl_${ABSL_CC_TEST_NAME}")
305
306  add_executable(${_NAME} "")
307  target_sources(${_NAME} PRIVATE ${ABSL_CC_TEST_SRCS})
308  target_include_directories(${_NAME}
309    PUBLIC ${ABSL_COMMON_INCLUDE_DIRS}
310    PRIVATE ${GMOCK_INCLUDE_DIRS} ${GTEST_INCLUDE_DIRS}
311  )
312
313  if (${ABSL_BUILD_DLL})
314    target_compile_definitions(${_NAME}
315      PUBLIC
316        ${ABSL_CC_TEST_DEFINES}
317        ABSL_CONSUME_DLL
318        GTEST_LINKED_AS_SHARED_LIBRARY=1
319    )
320
321    # Replace dependencies on targets inside the DLL with abseil_dll itself.
322    absl_internal_dll_targets(
323      DEPS ${ABSL_CC_TEST_DEPS}
324      OUTPUT ABSL_CC_TEST_DEPS
325    )
326  else()
327    target_compile_definitions(${_NAME}
328      PUBLIC
329        ${ABSL_CC_TEST_DEFINES}
330    )
331  endif()
332  target_compile_options(${_NAME}
333    PRIVATE ${ABSL_CC_TEST_COPTS}
334  )
335
336  target_link_libraries(${_NAME}
337    PUBLIC ${ABSL_CC_TEST_DEPS}
338    PRIVATE ${ABSL_CC_TEST_LINKOPTS}
339  )
340  # Add all Abseil targets to a folder in the IDE for organization.
341  set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
342
343  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
344  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
345
346  add_test(NAME ${_NAME} COMMAND ${_NAME})
347endfunction()
348
349
350function(check_target my_target)
351  if(NOT TARGET ${my_target})
352    message(FATAL_ERROR " ABSL: compiling absl requires a ${my_target} CMake target in your project,
353                   see CMake/README.md for more details")
354  endif(NOT TARGET ${my_target})
355endfunction()
356