CMAKE_INSTALL_EXPORTS_AS_PACKAGE_INFO

.. versionadded:: 4.3

.. note::

This variable is meaningful only when experimental support has been enabled by the CMAKE_EXPERIMENTAL_FIXME gate.

A list of directives instructing CMake to install |CPS| package information when exported target information is installed via :command:install(EXPORT). The value is treated as a list, with each directive having the form::

<export-name>:<package-name>[/[l][a<appendix-name>][/<destination>]]

Slashes are used to separate different components of the directive.

Note that this feature is intended for package distributors, and should only be used when editing a project's CMake script is not feasible. Developers should use :command:install(PACKAGE_INFO) directly.

Additionally, because CMAKE_INSTALL_EXPORTS_AS_PACKAGE_INFO functions by emulating a call to :command:install(PACKAGE_INFO), using it with a project that is already calling :command:install(PACKAGE_INFO) directly may result in conflicting installation directives, which will usually cause the project's configure step to fail.

The meaning of the values is as follows:

<export-name> Name of the export for which package information should be installed.

<package-name> Name of the package for which to generate package information. This is also the name that users would use in a :command:find_package call.

l Optional. Specifies that the name of the package information file on disk should be lower case. See the LOWER_CASE_FILE option of :command:install(PACKAGE_INFO).

a<appendix-name> Optional. Specifies that an appendix <appendix-name> should be created rather than a root package description. See the APPENDIX option of :command:install(PACKAGE_INFO). Note that additional information (see below) cannot be added to appendices.

<destination> Optional. Specifies the destination to which the package information file should be installed. See the DESTINATION option of :command:install(PACKAGE_INFO). Note that the default is a platform-specific location that is appropriate for |CPS| files in most instances, not the DESTINATION of the :command:install(EXPORT) which the directive matched.

For non-appendices, CMake will also infer additional information from several CMake variables of the form <export-name>_EXPORT_PACKAGE_INFO_<var>. The values of these are first processed as if by :command:string(CONFIGURE) with the @ONLY option. These are optional, and their effect is equivalent to passing their value to the <var> option of the :command:install(PACKAGE_INFO) command.

The additional variables are:

<export-name>_EXPORT_PACKAGE_INFO_VERSION
<export-name>_EXPORT_PACKAGE_INFO_COMPAT_VERSION
<export-name>_EXPORT_PACKAGE_INFO_VERSION_SCHEMA
<export-name>_EXPORT_PACKAGE_INFO_LICENSE
<export-name>_EXPORT_PACKAGE_INFO_DEFAULT_LICENSE
<export-name>_EXPORT_PACKAGE_INFO_DEFAULT_CONFIGURATIONS

Ideally, the version should be set to @PROJECT_VERSION@. However, some projects may not use the VERSION option of the :command:project command.

Example ^^^^^^^

Consider the following (simplified) project:

.. code-block:: cmake

project(Example VERSION 1.2.3 SPDX_LICENSE "BSD-3-Clause")

add_library(foo ...) add_library(bar ...)

install(TARGETS foo EXPORT required-targets) install(TARGETS bar EXPORT optional-targets)

install(EXPORT required-targets FILE example-targets.cmake ...) install(EXPORT optional-targets FILE example-optional-targets.cmake ...)

In this example, let example-targets.cmake be a file which is always installed, and example-optional-targets.cmake be a file which is optionally installed (e.g. is distributed as part of a separate package which depends on the 'base' package).

Now, imagine we are a distributor that wants to make |CPS| package information files available to our users, but we do not want to modify the project's build files. We can do this by passing the following arguments to CMake:

.. code-block::

-DCMAKE_EXPERIMENTAL_FIXME=<elided> -DCMAKE_INSTALL_EXPORTS_AS_PACKAGE_INFO=
required-targets:Example/l;
optional-targets:Example/laoptional -Drequired-targets_EXPORT_PACKAGE_INFO_VERSION=@Example_VERSION@ -Drequired-targets_EXPORT_PACKAGE_INFO_LICENSE=@Example_SPDX_LICENSE@

(Whitespace and line continuation characters, added for readability, should be removed in real usage. Arguments may need to be quoted to prevent being reinterpreted by the command shell.)

This will cause CMake to also create and install the files example.cps and example-optional.cps which describe the Example package. We could also specify the version and license information using substitutions provided by the package build system (e.g. rpm, dpkg) if the project does not provide this information via the :command:project command.

.. _CPS: https://cps-org.github.io/cps/ .. |CPS| replace:: Common Package Specification