Target generation

This project contains cmake helper functions to auto-generate library and executable targets

Libraries

Interface Library

To create an interface library make a directory in lib/<library name>/include with the desired library name. The library directory must contain an include directory to generate an interface library.

Static Library

Library targets will be auto-generated based off of directory structure. Any subdirectory in lib is assumed to be a library if there is a include and src directory that is not matched in the .cmakeignore file.

Example library:

The following directory structure will result in target: a being defined as a static library.

lib/a
├── include
│   └── a.h
└── src
    └──── a.cpp

• All include directories for all defined targets will be included into target a.
• All link libraries for all defined targets will be linked into target a.

Output:

Once target a is defined and make build is invoked the resulting output will be generated for target: a

build/lib
├── a
│   └── include
│       └── a.h
└── liba.a

• A build/lib directory will be generated with all artifacts for every library target.

• A build/share directory will be generated so that cmake find_package(<package name>) can be invoked on the package.

build/share
└── ── a
    └── cmake
        ├── aConfig.cmake
        └── aTargets.cmake

Note: the build/share directory needs to be appended to the CMAKE_PREFIX_PATH in order for cmake find_package to work

External packages

External cmake packages can be used. They should be included via a requirements.cmake file in the library directory.

All requirements.cmake files are recursively added during target generation.

The example library boost_hello requires boost. Inside lib/boost_hello/requirements.cmake find_package(Boost REQUIRED) is invoked.

The requirements.system captures any necessary Debian package management system (APT) requirements that are needed for the library. In this example it is libboost1.74-all-dev

Example boost_hello static library

lib/boost_hello
├── include
│   └── boost_hello.h
├── requirements.cmake
├── requirements.system
└── src
    └── boost_hello.cpp

A static shared library called boost_hello will be generated that is dependent on the external package Boost with the following output:

build/lib
├── boost_hello
│   └── include
│       └── boost_hello.h
└── libboost_hello.a

CMake share directory:

build/share
└── boost_hello
    └── cmake
        ├── boost_helloConfig.cmake
        └── boost_helloTargets.cmake

Executable targets

Any .cpp file anywhere in lib directory tree that is not matched in the .cmakeignore and contains a main method/function will auto-generate an executable target.

• All include directories for all defined targets will be included into the executable target.
• All link libraries for all defined targets will be linked into the executable target.

boost_hello_test_program example

Gives the following structure an executable target called boost_hello_test_program which contains a main method will be generated:

lib/boost_hello
├── include
│   └── boost_hello.h
├── requirements.cmake
├── requirements.system
└── src
    ├── boost_hello.cpp
    └── boost_hello_test_program.cpp

The executable target, in this case boost_hello_test_program can be anywhere in the directory tree for lib.

• All target include directories, such as for the library boost_hello, will be added to the target boost_hello_test_program
• All target link directories, such as for the library boost_hello, will be added to the target boost_hello_test_program

Once invoking make build an executable will be available in the build/bin directory with the same name as the executable target itself e.g, boost_hello_test_program.

.cmakeignore file

The .cmakeignore file provides a means to disable a target similar to the .gitignore file. Any pattern matching a directory in lib that is in the .cmakeignore will not auto-generate a target and will also not build. Review the comments in .cmakeignore for more information.