signals

A simple signals and slots library inspired by boost::signals2

Getting started

The following tools are needed to configure and build the project:

• CMake version 3.15 or later
• gcc version 11 or later Clang version 16 or later
• git
• Make or Ninja

Tools used to measure code coverage:

• lcov
• gcovr

Other tools used in this project:

• ClangFormat version 14
• GoogleTest (fetched at configure time)

Building

These instructions assume that the project has been cloned into a directory named signals. To configure and build a project, run the commands below.

$ cd signals
$ cmake -S . -B build/
$ cmake --build build/

This will create a static library named libsignals.a in the build/src/ folder.

The project builds a static library by default. To build a shared library, configure the project with BUILD_SHARED_LIBS=On.

$ cmake -DBUILD_SHARED_LIBS=On build/

Both GNU and Clang support colored diagnostics but depending on the build environment the colored output may not be enabled by default. To force colored diagnostics configure the project with COLOR_DIAGNOSTICS=On.

$ cmake -DCOLOR_DIAGNOSTICS=On build/

Building with MSVC and Ninja on Windows

Install Ninja (and ccache) in /usr/bin/ (or C:/Program Files/Git/usr/bin). Prepare the build environment by running the vcvarsall.bat script.

NOTE! In Git BASH, the environment variables set by the batch script are not propagated to the running shell. To work around this, run the command below.

$ eval "$(MSYS_NO_PATHCONV=1 cmd "/C "C:/Program Files \(x86\)/Microsoft Visual Studio/2019/Community/VC/Auxiliary/Build/vcvarsall.bat" amd64 > nul && \
  bash -c 'export -p'")"

To build the project run the below commands.

$ cmake -S . -B build/msvc -G Ninja
$ cmake --build build/msvc

Installing

By default, the install target installs the library in the /usr/local/lib/ folder. To change the installation directory, configure the project with CMAKE_INSTALL_PREFIX.

$ cmake -DCMAKE_INSTALL_PREFIX=build/ -DCMAKE_BUILD_TYPE=Release build/
$ cmake --build build/ --target install

The above command installs the library in the build/lib subdirectory.

NOTE! install target may require root permissions and is only available with Release builds

To uninstall, build the uninstall target or run xargs rm < build/install_manifest.txt.

To use the installed library with my-target, add the following lines to the CMakeLists.txt file.

find_package(signals REQUIRED)
target_link_libraries(my-target signals::signals)

Packaging

CMake comes with CPack, a cross-platform software packaging tool that makes it easy to create distributable packages. To create a binary package, run the command below.

$ cmake --build build --target package

To build a source package, run the command below.

$ cmake --build build --target package_source

Testing

This project is being developed using Test-driven development (TDD). Tests are written using the GoogleTest C++ test framework, which is fetched at configure time and built along with the tests.

To run unit tests, build the check target.

$ cmake --build build/ --target check

This builds and runs unit tests and shows a summary of the results. A more detailed message is shown if any of the tests fail.

NOTE! Unit tests are disabled by defauld when used as a subproject. To enable unit tests, configure the project with SIGNALS_TEST=On.

Code coverage

To measure code coverage, configure the project with CODE_COVERAGE=On and then build the code-coverage target.

$ cmake -DCODE_COVERAGE=On build/
$ cmake --build build/ --target check-coverage

This generates a code coverage report in the build/signals-coverage folder. View build/signals-coverage/index.html to see the results.

NOTE! Enabling code coverage forces the build type to be Debug

License

signals is distributed under the MIT license.