Use CMake to build libprotobuf and the C++ harness

This reuses some cmake logic from the protobuf dir,
which isn't ideal, but at least CMake knows how to handle
abseil.  <whew!>

Note:  This now expects abseil and googletests to be
already installed on the local system.  A more ambitious
setup here could potentially avoid that.

Author: tbkka

Performance/runners/CMakeLists.txt

@@ -0,0 +1,63 @@
+#
+# cmake configuration file for building the C++ test harness
+#
+# This assumes you have a protobuf source checkout handy,
+# and have used `git submodule update` to obtain all the
+# related source repos.
+#
+# This script uses the protobuf sources to build libprotobuf and
+# statically links it into the test harness executable.
+# (This is probably not necessary; updates to this file to
+# use a better strategy would be appreciated.)
+#
+# Also assumes that you have abseil_cpp and googletest installed
+# locally via e.g.,
+#   brew install googletest
+#   brew install abseil
+#
+
+cmake_minimum_required(VERSION 3.10...3.26)
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_BUILD_TYPE RelWithDebInfo)
+
+project(swiftprotobuf-perf C CXX)
+
+# Update this with the appropriate path to the protobuf source
+# checkout, starting from the directory holding this file.
+# Default here assumes that `protobuf` is checked out beside
+# `swift-protobuf`
+set(protobuf_SOURCE_DIR ${CMAKE_SOURCE_DIR}/../../../protobuf)
+set(protobuf_VERSION "999.999")
+
+# Use protobuf cmake scripts to locate suitable abseil package:
+set(protobuf_ABSL_PROVIDER "package")
+include(${protobuf_SOURCE_DIR}/cmake/abseil-cpp.cmake)
+
+# Use protobuf cmake scripts for building libprotobuf
+include(${protobuf_SOURCE_DIR}/cmake/libprotobuf.cmake)
+
+# Use utf8_range from protobuf checkout
+set(utf8_range_SOURCE_DIR ${protobuf_SOURCE_DIR}/third_party/utf8_range)
+add_subdirectory(${utf8_range_SOURCE_DIR} third_party/utf8_range)
+
+include_directories(
+  ${protobuf_SOURCE_DIR}/src
+  ${utf8_range_SOURCE_DIR}
+)
+
+add_executable(harness_cpp
+  ../main.cc
+  ../Harness.cc
+  ../_generated/Harness+Generated.cc
+  ../_generated/message.pb.cc
+)
+
+target_include_directories(harness_cpp PRIVATE
+  ${CMAKE_SOURCE_DIR}
+  ${CMAKE_SOURCE_DIR}/..
+  ${ABSL_ROOT_DIR}
+  ${utf8_range_SOURCE_DIR}
+)
+
+target_link_libraries(harness_cpp PRIVATE libprotobuf)

Performance/runners/cpp.sh

@@ -27,24 +27,12 @@ function run_cpp_harness() {
     generate_cpp_harness
 
     echo "Building C++ test harness..."
-    time ( g++ --std=c++11 -O \
-        -o "$harness" \
-        -I "$script_dir" \
-        -I "$GOOGLE_PROTOBUF_CHECKOUT/src" \
-        -L "$GOOGLE_PROTOBUF_CHECKOUT/src/.libs" \
-        -lprotobuf \
-        "$gen_harness_path" \
-        "$script_dir/Harness.cc" \
-        "$script_dir/_generated/message.pb.cc" \
-        "$script_dir/main.cc" \
-    )
-    echo
-
-    # Make sure the dylib is loadable from the harness if the user hasn't
-    # actually installed them.
-    cp "$GOOGLE_PROTOBUF_CHECKOUT"/src/.libs/libprotobuf.*.dylib \
-        "$script_dir/_generated"
 
+    pushd $script_dir/runners
+    cmake -B ../_generated -S .
+    cmake --build ../_generated
+    popd
+    
     run_harness_and_concatenate_results "C++" "$harness" "$partial_results"
   )
 }