generate_find_module.py

Descrition

A script to generate CMake Find Modules.

Usage

./generate_find_module.py --outdir

where:

outdir: Output directory name.

It uses packages.json to generate multiple Find Module scripts. The json file contains list of packages, each can define the following:

module_name: Name of the module to find. Examples: CURL, PCRE

include_file_name: Name of the include file to search for. Examples: curl.h, sqlite3.h, pcre.h

library_base_name: Name of the library file to search for. Examples: curl, sqlite3, pcre16

target_name: Name of the imported target that will be created. Examples: CURL::CURL, PCRE::PCRE16

package_name: Name of the package that will be passed to pkg-config (optional). Examples: libcurl, zlib, sqlite3

version_name: The name of the .cmake snippet under templates that can check the version of the library

Case study

Let's assume you want to create a find module for CURL. First thing to do is to figure out if CMake provides a find module for this library. This is the case for CURL, but we found out that the find module cmake provides does not create an imported target, so we need to create our custom find module using generate_find_module.

For that, we need several pieces of informations:

• The name of the include file we need to search for. In this case, the filename is curl.h

• The name of the library we need to search for. For CURL, the library name is libcurl.dylib on macOS and libcurl.so on other unices. So the library name we need to pass te generate_find_module.py is curl.

• The name of the pkg-config package CURL provides. We can find out using the following command: pkg-config --list-all|grep -i curl . In this case, the name of the pkg-config package is libcurl

We now have enough information to generate a find module. Let's create a packages.json like this:

{
  "packages" : [
    {
      "name": "CURL",
      "include": "curl.h",
      "lib": "curl",
      "target": "CURL::CURL",
      "package": "libcurl"
    }
  ]
}

Then you need to call generate_find_module.py

./generate_find_module.py

This will generate a FindCURL.cmake in the current directory. In case generation fails with formatting error, make sure to install (with pip) the 'cmakelang' package

Copy that file to your project's CMAKE_MODULE_PATH and add the following statement to your CMakeLists.txt:

find_library(CURL REQUIRED)

You can now link your target executable/library with the curl imported target:

target_link_libraries(${PROJECT_NAME} CURL::CURL)