cdk: cmake infrastructure for building external cmake projects

For exteranl dependencies, such as protobuf and compression libraries, their bundled sources are built as a separate, external cmake project and import targets are defined to refer to the produced libraries in the main project. New cmake commands add_ext() and add_ext_targets() are defined to manage this setup. Also, a mechanism to cache intial cmake settings and this way speed-up configuration of external projects is implemented.

Author: rsomla1

CMakeLists.txt

@@ -27,7 +27,7 @@
 # 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 
 
-CMAKE_MINIMUM_REQUIRED(VERSION 3.0)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.1)
 
 CMAKE_POLICY(VERSION 3.1)
 cmake_policy(SET CMP0022 NEW)
@@ -60,16 +60,23 @@ set(CMAKE_INSTALL_PREFIX "" CACHE PATH "Install location")
 #
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
+include(cdk/cmake/setup.cmake)
+include(cmake/setup.cmake)
+include(bootstrap)
+
+# Note: Does not work well with Ninja -- not sure why
+
+if(NOT CMAKE_GENERATOR MATCHES "Ninja")
+  bootstrap()
+endif()
+
 
 ##########################################################################
 
 PROJECT(MySQL_CONCPP)
 
 # Load cmake modules
 
-include(cdk/cmake/setup.cmake)
-include(cmake/setup.cmake)
-
 include(platform)
 include(dependency)      # find_dependency()
 include(config_options)  # add_config_option()

cdk/CMakeLists.txt

@@ -94,7 +94,7 @@ add_config(CDK_BIG_ENDIAN ${BIG_ENDIAN})
 #
 
 find_dependency(SSL)
-find_dependency(Protobuf)
+#find_dependency(Protobuf)
 find_dependency(RapidJSON)
 find_dependency(Coverage)
 

cdk/cmake/DepFindCompression.cmake

@@ -0,0 +1,60 @@
+# Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License, version 2.0, as
+# published by the Free Software Foundation.
+#
+# This program is also distributed with certain software (including
+# but not limited to OpenSSL) that is licensed under separate terms,
+# as designated in a particular file or component or in included license
+# documentation.  The authors of MySQL hereby grant you an
+# additional permission to link the program and your derivative works
+# with the separately licensed software that they have included with
+# MySQL.
+#
+# Without limiting anything contained in the foregoing, this file,
+# which is part of MySQL Connector/C++, is also subject to the
+# Universal FOSS Exception, version 1.0, a copy of which can be found at
+# http://oss.oracle.com/licenses/universal-foss-exception.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License, version 2.0, for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+
+##############################################################################
+#
+# Targets:
+#
+# (re)build-{zlib,lz4,zstd}
+#
+# Imported/alias targets:
+#
+# ext::zlib
+# ext::lz4
+# ext::zstd
+#
+# TODO:
+#  - allow use of external, dynamic libraries instead of static linking
+#
+
+if(TARGET ext::zlib)
+  return()
+endif()
+
+message(STATUS "Setting up compression libraries.")
+
+# Use external builds from the bundled sources
+
+add_ext(zlib)
+add_ext_targets(zlib zlib ext_zlib)
+
+add_ext(lz4)
+add_ext_targets(lz4 lz4 ext_lz4)
+
+add_ext(zstd)
+add_ext_targets(zstd zstd ext_zstd)