Use Fetchcontent instead of ExternalProject
Hi, instead of ExternalProject and a new file that is spawned in a new process, it's easier to just use FetchContent. cmake 3.14 should be old enough to be spread.
This commit is contained in:
		@@ -85,58 +85,18 @@ main build can be done a few different ways:
 | 
			
		||||
    is just a little more complex, but doesn't have the limitations of the other
 | 
			
		||||
    methods.
 | 
			
		||||
 | 
			
		||||
The last of the above methods is implemented with a small piece of CMake code in
 | 
			
		||||
a separate file (e.g. `CMakeLists.txt.in`) which is copied to the build area and
 | 
			
		||||
then invoked as a sub-build _during the CMake stage_. That directory is then
 | 
			
		||||
pulled into the main build with `add_subdirectory()`. For example:
 | 
			
		||||
The last of the above methods is implemented with a small piece of CMake code so
 | 
			
		||||
the code is pulled into the main build.
 | 
			
		||||
 | 
			
		||||
New file `CMakeLists.txt.in`:
 | 
			
		||||
Just add to your `CMakeLists.txt`:
 | 
			
		||||
 | 
			
		||||
```cmake
 | 
			
		||||
cmake_minimum_required(VERSION 2.8.12)
 | 
			
		||||
 | 
			
		||||
project(googletest-download NONE)
 | 
			
		||||
 | 
			
		||||
include(ExternalProject)
 | 
			
		||||
ExternalProject_Add(googletest
 | 
			
		||||
  GIT_REPOSITORY    https://github.com/google/googletest.git
 | 
			
		||||
  GIT_TAG           master
 | 
			
		||||
  SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
 | 
			
		||||
  BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
 | 
			
		||||
  CONFIGURE_COMMAND ""
 | 
			
		||||
  BUILD_COMMAND     ""
 | 
			
		||||
  INSTALL_COMMAND   ""
 | 
			
		||||
  TEST_COMMAND      ""
 | 
			
		||||
include (FetchContent)
 | 
			
		||||
FetchContent_Declare(
 | 
			
		||||
  googletest
 | 
			
		||||
  GIT_REPOSITORY https://github.com/google/googletest.git
 | 
			
		||||
)
 | 
			
		||||
```
 | 
			
		||||
 | 
			
		||||
Existing build's `CMakeLists.txt`:
 | 
			
		||||
 | 
			
		||||
```cmake
 | 
			
		||||
# Download and unpack googletest at configure time
 | 
			
		||||
configure_file(CMakeLists.txt.in googletest-download/CMakeLists.txt)
 | 
			
		||||
execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
 | 
			
		||||
  RESULT_VARIABLE result
 | 
			
		||||
  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
 | 
			
		||||
if(result)
 | 
			
		||||
  message(FATAL_ERROR "CMake step for googletest failed: ${result}")
 | 
			
		||||
endif()
 | 
			
		||||
execute_process(COMMAND ${CMAKE_COMMAND} --build .
 | 
			
		||||
  RESULT_VARIABLE result
 | 
			
		||||
  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
 | 
			
		||||
if(result)
 | 
			
		||||
  message(FATAL_ERROR "Build step for googletest failed: ${result}")
 | 
			
		||||
endif()
 | 
			
		||||
 | 
			
		||||
# Prevent overriding the parent project's compiler/linker
 | 
			
		||||
# settings on Windows
 | 
			
		||||
set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
 | 
			
		||||
 | 
			
		||||
# Add googletest directly to our build. This defines
 | 
			
		||||
# the gtest and gtest_main targets.
 | 
			
		||||
add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
 | 
			
		||||
                 ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
 | 
			
		||||
                 EXCLUDE_FROM_ALL)
 | 
			
		||||
FetchContent_MakeAvailable(googletest)
 | 
			
		||||
 | 
			
		||||
# Now simply link against gtest or gtest_main as needed. Eg
 | 
			
		||||
add_executable(example example.cpp)
 | 
			
		||||
@@ -144,10 +104,8 @@ target_link_libraries(example gtest_main)
 | 
			
		||||
add_test(NAME example_test COMMAND example)
 | 
			
		||||
```
 | 
			
		||||
 | 
			
		||||
Note that this approach requires CMake 2.8.2 or later due to its use of the
 | 
			
		||||
`ExternalProject_Add()` command. The above technique is discussed in more detail
 | 
			
		||||
in [this separate article](http://crascit.com/2015/07/25/cmake-gtest/) which
 | 
			
		||||
also contains a link to a fully generalized implementation of the technique.
 | 
			
		||||
Note that this approach requires CMake 3.14 or later due to its use of the
 | 
			
		||||
`FetchContent_MakeAvailable()` command.
 | 
			
		||||
 | 
			
		||||
##### Visual Studio Dynamic vs Static Runtimes
 | 
			
		||||
 | 
			
		||||
 
 | 
			
		||||
		Reference in New Issue
	
	Block a user