Cmake Project

This is a small project I used to learn cmake while migrating an existing build system to cmake

Structure

root
|
+---- foo                      # static library 
|     |
|     +---- test               # test for foo
|
+---- bar                      # static library, uses foo 
|     |
|     +---- test               # test for bar
|
+---- app                      # command line app, uses foo and bar
|
+---- gui                      # qt5 app, uses foo and bar

Build

• cmake

  mkdir build && cd build && cmake .. && make

Features

version information

Version information is generated and a version.cc file generated.

The output of printing this information is similar to this:

build variant : release
build date    : Feb 27 2018 10:56:11
version       : 083b581
num_commits   : 78
branch        : master
ahead_by      : 0
num_untracked : 0
user          : steve
hostname      : ky-steve

Tests

Tests are run as part of the build process

A failing test breaks the build

All tests are run through valgrind

A memory leak breaks the build

Files:

• scripts/cmake/test.cmake: cmake function which adds the test and configures it to run as part of the build

Tagged binaries:

Binaries can be installed to a specified destination as part of the build, and optionally have version information included in the filename

Version information tagged onto a binary:

• branch : branch name binary is built from
• commits : number of commits in this branch
• dirty : whether the branch is clean, or has uncommitted changes, untracked files etc

Files:

• scripts/cmake/install.cmake: cmake function which installs the binary, and tags it with version information (wip)

Modules

Related targets can be added to a "module", such that building the module builds all related targets

eg: foo module contains libfoo static library and foo_test, tests which verify libfoo

foo exists as a target in the makefiles. make foo builds all related targets.

Build settings

Top level CMakeLists.txt includes all.cmake, which pulls in all the custom cmake scripts.

Additionally, all.cmake pulls in several scripts which configure the build

• scripts/cmake/ccache.cmake: builds through ccache if it is found
• scripts/cmake/default_build.cmake: sets the default build to Debug if it hasn't been specified
• scripts/cmake/compile_flags.cmake: compiler flags set for the build
• scripts/cmake/dependencies.cmake: pulls in 3rd party dependencies

Quickstart

There is a script bootstrap in the root directory which will set up the cmake files automatically.

The bootstrap script will install 2 sets of makefiles, for debug and release builds.

These are installed to cmake_test/.build/debug and cmake_test/.build/release respectively.

The bootstrap script will also install makefiles into the source tree, allowing you to build from within the source tree. These makefiles delegate the build to the appropriate out-of-source makefiles.

These in-source makefiles allow you to build either debug or release (debug is default), and to optionally list a target to build (default is all targets at-or-below the current location in the source tree)

Examples

$ make              # builds all targets at-or-below the current location in the source tree in debug mode
$ make release      # builds all targets at-or-below the current location in the source tree in release mode
$ make foo          # builds the foo target in debug mode
$ make foo release  # builds the foo target in release mode