Install absel along with gRPC (#26802)

cmake/abseil-cpp.cmake

@@ -17,15 +17,12 @@ if(gRPC_ABSL_PROVIDER STREQUAL "module")
     set(ABSL_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/abseil-cpp)
   endif()
   if(EXISTS "${ABSL_ROOT_DIR}/CMakeLists.txt")
-    add_subdirectory(${ABSL_ROOT_DIR} third_party/abseil-cpp)
-    if(TARGET absl_base)
-      if(gRPC_INSTALL AND _gRPC_INSTALL_SUPPORTED_FROM_MODULE)
-        install(TARGETS ${gRPC_ABSL_USED_TARGETS} EXPORT gRPCTargets
-          RUNTIME DESTINATION ${gRPC_INSTALL_BINDIR}
-          LIBRARY DESTINATION ${gRPC_INSTALL_LIBDIR}
-          ARCHIVE DESTINATION ${gRPC_INSTALL_LIBDIR})
-      endif()
+    if(gRPC_INSTALL)
+      # When gRPC_INSTALL is enabled and Abseil will be built as a module,
+      # Abseil will be installed along with gRPC for convenience.
+      set(ABSL_ENABLE_INSTALL ON)
     endif()
+    add_subdirectory(${ABSL_ROOT_DIR} third_party/abseil-cpp)
   else()
     message(WARNING "gRPC_ABSL_PROVIDER is \"module\" but ABSL_ROOT_DIR is wrong")
   endif()
@@ -36,5 +33,5 @@ if(gRPC_ABSL_PROVIDER STREQUAL "module")
 elseif(gRPC_ABSL_PROVIDER STREQUAL "package")
   # Use "CONFIG" as there is no built-in cmake module for absl.
   find_package(absl REQUIRED CONFIG)
-  set(_gRPC_FIND_ABSL "if(NOT absl_FOUND)\n  find_package(absl CONFIG)\nendif()")
 endif()
+set(_gRPC_FIND_ABSL "if(NOT TARGET absl::strings)\n  find_package(absl CONFIG)\nendif()")

test/distrib/cpp/run_distrib_test_cmake_aarch64_cross.sh

@@ -53,17 +53,6 @@ set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
 EOT
 
-# Build and install absl (absl won't be installed down below)
-mkdir -p "third_party/abseil-cpp/cmake/build_arm"
-pushd "third_party/abseil-cpp/cmake/build_arm"
-cmake -DCMAKE_TOOLCHAIN_FILE=/tmp/toolchain.cmake \
-      -DCMAKE_BUILD_TYPE=Release \
-      -DCMAKE_INSTALL_PREFIX=/tmp/install \
-      -DCMAKE_POSITION_INDEPENDENT_CODE=TRUE \
-      ../..
-make -j4 install
-popd
-
 # Build and install gRPC for ARM.
 # This build will use the host architecture copies of protoc and
 # grpc_cpp_plugin that we built earlier because we installed them
@@ -84,6 +73,7 @@ mkdir -p "examples/cpp/helloworld/cmake/build_arm"
 pushd "examples/cpp/helloworld/cmake/build_arm"
 cmake -DCMAKE_TOOLCHAIN_FILE=/tmp/toolchain.cmake \
       -DCMAKE_BUILD_TYPE=Release \
+      -Dabsl_DIR=/tmp/stage/lib/cmake/absl \
       -DProtobuf_DIR=/tmp/stage/lib/cmake/protobuf \
       -DgRPC_DIR=/tmp/stage/lib/cmake/grpc \
       ../..

test/distrib/cpp/run_distrib_test_cmake_module_install.sh

@@ -26,13 +26,6 @@ wget -q -O cmake-linux.sh https://github.com/Kitware/CMake/releases/download/v3.
 sh cmake-linux.sh -- --skip-license --prefix=/usr
 rm cmake-linux.sh
 
-# Install absl (absl won't be installed down below)
-mkdir -p "third_party/abseil-cpp/cmake/build"
-pushd "third_party/abseil-cpp/cmake/build"
-cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_POSITION_INDEPENDENT_CODE=TRUE ../..
-make -j4 install
-popd
-
 # Install gRPC and its dependencies
 mkdir -p "cmake/build"
 pushd "cmake/build"
@@ -40,7 +33,6 @@ cmake \
   -DCMAKE_BUILD_TYPE=Release \
   -DgRPC_INSTALL=ON \
   -DgRPC_BUILD_TESTS=OFF \
-  -DgRPC_ABSL_PROVIDER=package \
   -DgRPC_SSL_PROVIDER=package \
   ../..
 make -j4 install

test/distrib/cpp/run_distrib_test_cmake_module_install_pkgconfig.sh

@@ -26,13 +26,6 @@ wget -q -O cmake-linux.sh https://github.com/Kitware/CMake/releases/download/v3.
 sh cmake-linux.sh -- --skip-license --prefix=/usr
 rm cmake-linux.sh
 
-# Install absl (absl won't be installed down below)
-mkdir -p "third_party/abseil-cpp/cmake/build"
-pushd "third_party/abseil-cpp/cmake/build"
-cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_POSITION_INDEPENDENT_CODE=TRUE ../..
-make -j4 install
-popd
-
 # Install gRPC and its dependencies
 mkdir -p "cmake/build"
 pushd "cmake/build"
@@ -40,7 +33,6 @@ cmake \
   -DCMAKE_BUILD_TYPE=Release \
   -DgRPC_INSTALL=ON \
   -DgRPC_BUILD_TESTS=OFF \
-  -DgRPC_ABSL_PROVIDER=package \
   -DgRPC_SSL_PROVIDER=package \
   ../..
 make -j4 install