Using peel with CMake

Many C++ projects are built with CMake. peel provides a CMake package to make it easier to use peel in CMake projects.

Start by importing the peel CMake package:

# CMakeLists.txt

find_package (peel REQUIRED)

This will look for the file named peel-config.cmake, which peel installs into $libdir/cmake/peel/ (e.g. /usr/lib64/cmake/peel/peel-config.cmake). If you have peel installed into a non-standard prefix, you can tell CMake to look there by passing it as CMAKE_PREFIX_PATH value at project configuration time. See the CMake Using Dependencies Guide for more details about how find_package can be used, and where CMake looks for packages.

The peel CMake package defines the peel::peel imported target, which you can use when defining another target to add peel’s own (non-generated) header directory to the include path:

find_package (peel REQUIRED)

add_executable (my-app main.cpp)
target_link_libraries (my-app PRIVATE peel::peel)

To run the bindings generator, use the peel_generate function:

find_package (peel REQUIRED)
peel_generate (Gtk 4.0 RECURSIVE)

This function will, at build time, create a peel-generated directory inside the current build directory and run the peel generator to generate bindings inside of it. The function defines an imported target which is named same as the first argument (the GIR repo name, so in this case, peel::Gtk); this imported target can be linked into another target to add the peel-generated directory to the include path, as well as to ensure a proper dependency edge between generating bindings and compiling the dependent target.

Note that the peel imported target does not, by itself, link to the actual library you’re generating bindings for; you still need to do that yourself. So a complete working example of using peel with GTK 4 might look like this:

# Find GTK 4 using pkg-config:
find_package (PkgConfig)
pkg_check_modules (gtk4 IMPORTED_TARGET gtk4 REQUIRED)

# Find peel and generate bindings for GTK 4:
find_package (peel REQUIRED)
peel_generate (Gtk 4.0 RECURSIVE)

add_executable (my-app main.cpp)
# Build and link the executable with GTK 4,
# as well as peel bindings for GTK 4:
target_link_libraries (my-app PRIVATE PkgConfig::gtk4 peel::Gtk)

See examples/cmake-project in the peel repository for a small, yet complete example of a CMake project that uses GTK 4 with peel.