Revert "Use modern CMake and use FetchContent for msgpack"

This reverts commit a17e3fd.

CMakeLists.txt

@@ -1,6 +1,10 @@
-cmake_minimum_required(VERSION 3.16)
-cmake_policy(SET CMP0048 NEW)
-cmake_policy(SET CMP0069 NEW)
+cmake_minimum_required(VERSION 2.8.12)
+if (POLICY CMP0048)
+  cmake_policy(SET CMP0048 NEW)
+endif (POLICY CMP0048)
+if (POLICY CMP0069)
+  cmake_policy(SET CMP0069 NEW)
+endif (POLICY CMP0069)
 
 # Neovim-Qt Version, used by --version update before release
 # 9999 = Development Pre-Release
@@ -145,6 +149,7 @@ if(USE_SYSTEM_MSGPACK)
 else()
 	add_subdirectory(third-party)
 endif()
+include_directories(${MSGPACK_INCLUDE_DIRS})
 
 if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     add_definitions(-DQT_NO_DEBUG_OUTPUT)

cmake/FindMsgpack.cmake

@@ -0,0 +1,17 @@
+include(CheckLibraryExists)
+
+find_path(MSGPACK_INCLUDE_DIR
+    NAMES msgpack.h
+)
+
+find_library(MSGPACK_LIBRARY
+    NAMES msgpack msgpackc libmsgpack.a libmsgpackc.a
+)
+
+mark_as_advanced(MSGPACK_INCLUDE_DIR MSGPACK_LIBRARY)
+set(MSGPACK_LIBRARIES ${MSGPACK_LIBRARY})
+set(MSGPACK_INCLUDE_DIRS ${MSGPACK_INCLUDE_DIR})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Msgpack DEFAULT_MSG
+	MSGPACK_LIBRARY MSGPACK_INCLUDE_DIR)

src/CMakeLists.txt

@@ -22,6 +22,6 @@ if(WIN32)
 endif()
 
 add_library(neovim-qt STATIC ${NEOVIM_QT_SOURCES})
-target_link_libraries(neovim-qt Qt5::Network msgpackc-static)
+target_link_libraries(neovim-qt Qt5::Network ${MSGPACK_LIBRARIES})
 
 add_subdirectory(gui)

src/gui/CMakeLists.txt

@@ -67,7 +67,7 @@ add_executable(nvim-qt WIN32 MACOSX_BUNDLE main.cpp
 	${RES_FILE}
 	${ICON_PATH})
 
-target_link_libraries(nvim-qt ${QTLIBS} neovim-qt-gui)
+target_link_libraries(nvim-qt ${QTLIBS} ${MSGPACK_LIBRARIES} neovim-qt-gui)
 
 if(APPLE)
 	add_custom_command(TARGET nvim-qt COMMAND ${CMAKE_COMMAND} -E copy_directory

src/gui/shellwidget/CMakeLists.txt

@@ -1,6 +1,7 @@
-cmake_minimum_required(VERSION 3.16)
-cmake_policy(SET CMP0048 NEW)
-
+cmake_minimum_required(VERSION 2.8.12)
+if (POLICY CMP0048)
+  cmake_policy(SET CMP0048 NEW)
+endif (POLICY CMP0048)
 project(qshellwidget)
 
 set(CMAKE_INCLUDE_CURRENT_DIR ON)

third-party/CMakeLists.txt

@@ -1,20 +1,34 @@
 # This is a minimal CMake project to fetch and build third party
 # dependencies
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 2.8.12)
+if (POLICY CMP0048)
+  cmake_policy(SET CMP0048 NEW)
+endif (POLICY CMP0048)
+project(neovim-qt-deps)
 
-cmake_policy(SET CMP0048 NEW)
-if (POLICY CMP0135)
-  cmake_policy(SET CMP0135 NEW)
-endif()
+#
+# Get Msgpack
+#
+set(MSGPACK_VERSION 3.2.0)
+set(MSGPACK_URL https://github.com/msgpack/msgpack-c/archive/cpp-${MSGPACK_VERSION}.tar.gz)
+set(MSGPACK_SHA256 ff865a36bad5c72b8e7ebc4b7cf5f27a820fce4faff9c571c1791e3728355a39)
 
-project(neovim-qt-deps)
+message(STATUS "Downloading Msgpack...")
+set(MSGPACK_TARBALL msgpack-${MSGPACK_VERSION}.tar.gz)
+file(DOWNLOAD ${MSGPACK_URL} ${CMAKE_CURRENT_SOURCE_DIR}/${MSGPACK_TARBALL}
+	INACTIVITY_TIMEOUT 30
+	EXPECTED_HASH SHA256=${MSGPACK_SHA256})
+execute_process(COMMAND ${CMAKE_COMMAND} -E tar xfz ${MSGPACK_TARBALL}
+	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+	RESULT_VARIABLE rv)
+if(NOT rv EQUAL 0)
+  message(FATAL_ERROR "Failed to extract ${MSGPACK_TARBALL}")
+endif()
 
-include(FetchContent)
+set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR})
+set(MSGPACK_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/msgpack-c-cpp-${MSGPACK_VERSION}/)
+add_subdirectory(${MSGPACK_SOURCE_DIR} EXCLUDE_FROM_ALL)
 
-set(MSGPACK_VERSION 3.2.0)
-FetchContent_Declare(
-    msgpackc
-    URL "https://github.com/msgpack/msgpack-c/archive/cpp-${MSGPACK_VERSION}.tar.gz"
-    URL_HASH SHA256=ff865a36bad5c72b8e7ebc4b7cf5f27a820fce4faff9c571c1791e3728355a39
-)
-FetchContent_MakeAvailable(msgpackc)
+# Similar enough to FindMsgpack
+set(MSGPACK_INCLUDE_DIRS ${MSGPACK_SOURCE_DIR}/include PARENT_SCOPE)
+set(MSGPACK_LIBRARIES msgpackc-static PARENT_SCOPE)