Add CMake Install rules (abseil#111)

CMake/AbseilHelpers.cmake

@@ -66,17 +66,17 @@ set(ABSL_IDE_FOLDER Abseil)
 # TODO: Implement "ALWAYSLINK"
 function(absl_cc_library)
   cmake_parse_arguments(ABSL_CC_LIB
-    "DISABLE_INSTALL;PUBLIC;TESTONLY"
+    "PUBLIC;TESTONLY"
     "NAME"
     "HDRS;SRCS;COPTS;DEFINES;LINKOPTS;DEPS"
     ${ARGN}
   )
 
   if (NOT ABSL_CC_LIB_TESTONLY OR ABSL_RUN_TESTS)
     if (ABSL_CC_LIB_PUBLIC)
-      set(_NAME "absl_${ABSL_CC_LIB_NAME}")
+      set(_NAME "${ABSL_CC_LIB_NAME}")
     else()
-      set(_NAME "absl_internal_${ABSL_CC_LIB_NAME}")
+      set(_NAME "${ABSL_CC_LIB_NAME}_")
     endif()
 
     # Check if this is a header-only library
@@ -88,9 +88,15 @@ function(absl_cc_library)
 
     if(NOT ABSL_CC_LIB_IS_INTERFACE)
       add_library(${_NAME} STATIC "")
+      set_target_properties(${_NAME} PROPERTIES
+        OUTPUT_NAME "absl_${_NAME}"
+      )
       target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
       target_include_directories(${_NAME}
-        PUBLIC ${ABSL_COMMON_INCLUDE_DIRS})
+        PUBLIC
+          $<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>
+          $<INSTALL_INTERFACE:include>
+      )
       # TODO(rongjiecomputer): Revisit ABSL_COMPILE_CXXFLAGS when fixing GH#123
       target_compile_options(${_NAME}
         PRIVATE ${ABSL_COMPILE_CXXFLAGS} ${ABSL_CC_LIB_COPTS})
@@ -106,7 +112,10 @@ function(absl_cc_library)
       # Generating header-only library
       add_library(${_NAME} INTERFACE)
       target_include_directories(${_NAME}
-        INTERFACE ${ABSL_COMMON_INCLUDE_DIRS})
+        INTERFACE
+          $<BUILD_INTERFACE:${ABSL_COMMON_INCLUDE_DIRS}>
+          $<INSTALL_INTERFACE:include>
+      )
       target_link_libraries(${_NAME}
         INTERFACE ${ABSL_CC_LIB_DEPS} ${ABSL_CC_LIB_LINKOPTS}
       )
@@ -116,6 +125,16 @@ function(absl_cc_library)
     if(ABSL_CC_LIB_PUBLIC OR ABSL_CC_LIB_TESTONLY)
       add_library(absl::${ABSL_CC_LIB_NAME} ALIAS ${_NAME})
     endif()
+
+    # Install rules
+    if(NOT ABSL_DISABLE_INSTALL AND ABSL_CC_LIB_PUBLIC)
+      install(TARGETS ${ABSL_CC_LIB_NAME}
+        EXPORT ${PROJECT_NAME}-targets
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      )
+    endif()
+
   endif()
 endfunction()
 

CMake/absl-config.cmake

@@ -0,0 +1 @@
+include("${CMAKE_CURRENT_LIST_DIR}/absl-targets.cmake"

CMakeLists.txt

@@ -21,9 +21,13 @@ project(absl)
 
 list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/CMake)
 
-include(GNUInstallDirs)
-include(AbseilHelpers)
+option(ABSL_DISABLE_INSTALL "If ON, Abseil disable install rules." OFF)
+
+if(NOT ABSL_DISABLE_INSTALL)
+  include(GNUInstallDirs)
+endif()
 
+include(AbseilHelpers)
 
 # config options
 if (MSVC)
@@ -103,3 +107,14 @@ if(BUILD_TESTING)
 endif()
 
 add_subdirectory(absl)
+
+if(NOT ABSL_DISABLE_INSTALL)
+  set(CMAKE_INSTALL_CONFIGDIR ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME})
+  install(EXPORT ${PROJECT_NAME}-targets
+    NAMESPACE absl::
+    DESTINATION ${CMAKE_INSTALL_CONFIGDIR}
+  )
+  install(FILES CMake/${PROJECT_NAME}-config.cmake
+    DESTINATION ${CMAKE_INSTALL_CONFIGDIR}
+  )
+endif()