Add absl to CMake and Bazel builds. (#1301)

CMakeLists.txt

@@ -29,6 +29,7 @@ include("${PROJECT_SOURCE_DIR}/cmake/functions.cmake")
 google_initialize_cartographer_project()
 google_enable_testing()
 
+find_package(Abseil REQUIRED)
 find_package(Boost REQUIRED COMPONENTS iostreams)
 find_package(Ceres REQUIRED COMPONENTS SuiteSparse)
 find_package(Eigen3 REQUIRED)
@@ -225,7 +226,7 @@ target_include_directories(${PROJECT_NAME} SYSTEM PUBLIC
   ${PROTOBUF_INCLUDE_DIR})
 # TODO(hrapp): This should not explicitly list pthread and use
 # PROTOBUF_LIBRARIES, but that failed on first try.
-target_link_libraries(${PROJECT_NAME} PUBLIC ${PROTOBUF_LIBRARY} pthread)
+target_link_libraries(${PROJECT_NAME} PUBLIC ${PROTOBUF_LIBRARY} pthread standalone_absl)
 if(${BUILD_GRPC})
   target_link_libraries(${PROJECT_NAME} PUBLIC grpc++)
   target_link_libraries(${PROJECT_NAME} PUBLIC async_grpc)

bazel/repositories.bzl

@@ -233,6 +233,12 @@ def cartographer_repositories():
           "https://github.com/googlecartographer/async_grpc/archive/ed8e3b31bdd46a74f0c47b4c53a47e0c0f21141b.tar.gz",
       ],
   )
+  _maybe(native.http_archive,
+      name = "com_google_absl",
+      sha256 = "387cf016ab1ab8530d1cea8975276ce8d8bff355133776129bdc400d05519eb6",
+      strip_prefix = "abseil-cpp-44aa275286baf97fc13529aca547a88b180beb08",
+      urls = ["https://github.com/abseil/abseil-cpp/archive/44aa275286baf97fc13529aca547a88b180beb08.tar.gz"],
+  )
 
   # TODO(rodrigoq): remove these binds once grpc#14140 has been merged, as well
   # as removing `use_external` in cartographer_grpc/BUILD.bazel.

cartographer/BUILD.bazel

@@ -100,6 +100,7 @@ cc_library(
         "@org_ceres_solver_ceres_solver//:ceres",
         "@org_lua_lua//:lua",
         "@org_tuxfamily_eigen//:eigen",
+        "@com_google_absl//absl/strings",
     ],
 )
 

cmake/modules/FindAbseil.cmake

@@ -0,0 +1,77 @@
+# Copyright 2018 The Cartographer Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required(VERSION 3.2)
+
+if(NOT TARGET standalone_absl)
+  include(${CMAKE_ROOT}/Modules/ExternalProject.cmake)
+  set(ABSEIL_PROJECT_NAME abseil)
+  set(ABSEIL_PROJECT_SRC_DIR
+    ${CMAKE_CURRENT_BINARY_DIR}/${ABSEIL_PROJECT_NAME}/src/${ABSEIL_PROJECT_NAME})
+  set(ABSEIL_PROJECT_BUILD_DIR
+    ${CMAKE_CURRENT_BINARY_DIR}/${ABSEIL_PROJECT_NAME}/src/${ABSEIL_PROJECT_NAME}-build)
+  set(ABSEIL_INCLUDE_DIRS ${ABSEIL_PROJECT_SRC_DIR})
+  set(ABSEIL_LIBRARY_PATH
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/synchronization/libabsl_synchronization.a")
+  set(ABSEIL_DEPENDENT_LIBRARIES
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/algorithm/libabsl_algorithm.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/base/libabsl_base.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/base/libabsl_dynamic_annotations.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/base/libabsl_malloc_internal.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/base/libabsl_spinlock_wait.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/base/libabsl_throw_delegate.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/container/libabsl_container.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/container/libtest_instance_tracker_lib.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_debugging.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_examine_stack.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_failure_signal_handler.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_leak_check.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_stack_consumption.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_stacktrace.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/debugging/libabsl_symbolize.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/memory/libabsl_memory.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/meta/libabsl_meta.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/numeric/libabsl_int128.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/numeric/libabsl_numeric.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/strings/libabsl_strings.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/time/libabsl_time.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_any.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_bad_any_cast.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_bad_optional_access.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_optional.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_span.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/libabsl_variant.a"
+    "${ABSEIL_PROJECT_BUILD_DIR}/absl/utility/libabsl_utility.a"
+    )
+  ExternalProject_Add(${ABSEIL_PROJECT_NAME}
+    PREFIX ${ABSEIL_PROJECT_NAME}
+    GIT_REPOSITORY   https://github.com/abseil/abseil-cpp.git
+    GIT_TAG          44aa275286baf97fc13529aca547a88b180beb08
+    INSTALL_COMMAND  ""
+    CMAKE_CACHE_ARGS "-DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=ON;-DBUILD_TESTING:BOOL=OFF;-DCMAKE_BUILD_TYPE:STRING=Release"
+    BUILD_BYPRODUCTS "${ABSEIL_LIBRARY_PATH};${ABSEIL_DEPENDENT_LIBRARIES}"
+  )
+  add_library(standalone_absl STATIC IMPORTED)
+  set_target_properties(standalone_absl
+    PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
+    ${ABSEIL_INCLUDE_DIRS}
+  )
+  set_target_properties(standalone_absl
+    PROPERTIES IMPORTED_LOCATION
+    ${ABSEIL_LIBRARY_PATH}
+    INTERFACE_LINK_LIBRARIES
+    "${ABSEIL_DEPENDENT_LIBRARIES}"
+  )
+  add_dependencies(standalone_absl ${ABSEIL_PROJECT_NAME})
+endif()