### Generic Build Instructions ###
#### Setup ####
To build Google Test and your tests that use it, you need to tell your
build system where to find its headers and source files. The exact
way to do it depends on which build system you use, and is usually
straightforward.
#### Build ####
Suppose you put Google Test in directory `${GTEST_DIR}`. To build it,
create a library build target (or a project as called by Visual Studio
and Xcode) to compile
${GTEST_DIR}/src/gtest-all.cc
with `${GTEST_DIR}/include` in the system header search path and `${GTEST_DIR}`
in the normal header search path. Assuming a Linux-like system and gcc,
something like the following will do:
g++ -isystem ${GTEST_DIR}/include -I${GTEST_DIR} \
-pthread -c ${GTEST_DIR}/src/gtest-all.cc
ar -rv libgtest.a gtest-all.o
(We need `-pthread` as Google Test uses threads.)
Next, you should compile your test source file with
`${GTEST_DIR}/include` in the system header search path, and link it
with gtest and any other necessary libraries:
g++ -isystem ${GTEST_DIR}/include -pthread path/to/your_test.cc libgtest.a \
-o your_test
As an example, the make/ directory contains a Makefile that you can
use to build Google Test on systems where GNU make is available
(e.g. Linux, Mac OS X, and Cygwin). It doesn't try to build Google
Test's own tests. Instead, it just builds the Google Test library and
a sample test. You can use it as a starting point for your own build
script.
If the default settings are correct for your environment, the
following commands should succeed:
cd ${GTEST_DIR}/make
make
./sample1_unittest
If you see errors, try to tweak the contents of `make/Makefile` to make
them go away. There are instructions in `make/Makefile` on how to do
it.
### Using CMake ###
Google Test comes with a CMake build script (
[CMakeLists.txt](CMakeLists.txt)) that can be used on a wide range of platforms ("C" stands for
cross-platform.). If you don't have CMake installed already, you can
download it for free from <http://www.cmake.org/>.
CMake works by generating native makefiles or build projects that can
be used in the compiler environment of your choice. You can either
build Google Test as a standalone project or it can be incorporated
into an existing CMake build for another project.
#### Standalone CMake Project ####
When building Google Test as a standalone project, the typical
workflow starts with:
mkdir mybuild # Create a directory to hold the build output.
cd mybuild
cmake ${GTEST_DIR} # Generate native build scripts.
If you want to build Google Test's samples, you should replace the
last command with
cmake -Dgtest_build_samples=ON ${GTEST_DIR}
If you are on a \*nix system, you should now see a Makefile in the
current directory. Just type 'make' to build gtest.
If you use Windows and have Visual Studio installed, a `gtest.sln` file
and several `.vcproj` files will be created. You can then build them
using Visual Studio.
On Mac OS X with Xcode installed, a `.xcodeproj` file will be generated.
#### Incorporating Into An Existing CMake Project ####
If you want to use gtest in a project which already uses CMake, then a
more robust and flexible approach is to build gtest as part of that
project directly. This is done by making the GoogleTest source code
available to the main build and adding it using CMake's
`add_subdirectory()` command. This has the significant advantage that
the same compiler and linker settings are used between gtest and the
rest of your project, so issues associated with using incompatible
libraries (eg debug/release), etc. are avoided. This is particularly
useful on Windows. Making GoogleTest's source code available to the
main build can be done a few different ways:
* Download the GoogleTest source code manually and place it at a
known location. This is the least flexible approach and can make
it more difficult to use with continuous integration systems, etc.
* Embed the GoogleTest source code as a direct copy in the main
project's source tree. This is often the simplest approach, but is
also the hardest to keep up to date. Some organizations may not
permit this method.
* Add GoogleTest as a git submodule or equivalent. This may not
always be possible or appropriate. Git submodules, for example,
have their own set of advantages and drawbacks.
* Use CMake to download GoogleTest as part of the build's configure
step. This 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:
New file `CMakeLists.txt.in`:
cmake_minimum_required(VERSION 2.8.2)
project(googletest-download NONE)
include(ExternalProject)
ExternalProject_Add(googletest
GIT_REPOSITORY https://github.com/google/googletest.git
GIT_TAG master
SOURCE_DIR "${CMAKE_BINARY_DIR}/googletest-src"
BINARY_DIR "${CMAKE_BINARY_DIR}/googletest-build"
CONFIGURE_COMMAND ""
BUILD_COMMAND ""
INSTALL_COMMAND ""
TEST_COMMAND ""
)
Existing build's `CMakeLists.txt`:
# 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_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_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_BINARY_DIR}/googletest-src
${CMAKE_BINARY_DIR}/googletest-build
EXCLUDE_FROM_ALL)
# The gtest/gtest_main targets carry header search path
# dependencies automatically when using CMake 2.8.11 or
# later. Otherwise we have to add them here ourselves.
if (CMAKE_VERSION VERSION_LESS 2.8.11)
include_directories("${gtest_SOURCE_DIR}/include")
endif()
# Now simply link against gtest or gtest_main as needed. Eg
add_executable(example example.cpp)
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.
##### Visual Studio Dynamic vs Static Runtimes #####
By default, new Visual Studio projects link the C runtimes dynamically
but Google Test links them statically.
This will generate an error that looks something like the following:
gtest.lib(gtest-all.obj) : error LNK2038: mismatch detected for 'RuntimeLibrary': value 'MTd_StaticDebug' doesn't match value 'MDd_DynamicDebug' in main.obj
Google Test already has a CMake option for this: `gtest_force_shared_crt`
Enabling this option will make gtest link the runtimes dynamically too,
and match the project in which it is included.
### Legacy Build Scripts ###
Before settling on CMake, we have been providing hand-maintained build
projects/scripts f