# ECMSetupVersion

Handle library version information.

    ecm_setup_version(<version>
                      VARIABLE_PREFIX <prefix>
                      [SOVERSION <soversion>]
                      [VERSION_HEADER <filename>]
                      [PACKAGE_VERSION_FILE <filename> [COMPATIBILITY <compat>]] )

This parses a version string and sets up a standard set of version variables. It can optionally also create a C version header file and a CMake package version file to install along with the library.

If the `<version>` argument is of the form `<major>.<minor>.<patch>` (or `<major>.<minor>.<patch>.<tweak>`), The following CMake variables are set:

    <prefix>_VERSION_MAJOR  - <major>
    <prefix>_VERSION_MINOR  - <minor>
    <prefix>_VERSION_PATCH  - <patch>
    <prefix>_VERSION        - <version>
    <prefix>_SOVERSION      - <soversion>, or <major> if SOVERSION was not given

For backward-compatibility also this variable is set (only if the minimum required version of ECM is < 5.83):

    <prefix>_VERSION_STRING - <version> (use <prefix>_VERSION instead)

If CMake policy CMP0048 is not `NEW`, the following CMake variables will also be set:

    PROJECT_VERSION_MAJOR   - <major>
    PROJECT_VERSION_MINOR   - <minor>
    PROJECT_VERSION_PATCH   - <patch>
    PROJECT_VERSION         - <version>

For backward-compatibility, if CMake policy CMP0048 is not `NEW`, also this variable is set (only if the minimum required version of ECM is < 5.83):

    PROJECT_VERSION_STRING  - <version> (use PROJECT_VERSION instead)

If the `VERSION_HEADER` option is used, a simple C header is generated with the given filename. If filename is a relative path, it is interpreted as relative to `CMAKE_CURRENT_BINARY_DIR`. The generated header contains the following macros:

    <prefix>_VERSION_MAJOR  - <major> as an integer
    <prefix>_VERSION_MINOR  - <minor> as an integer
    <prefix>_VERSION_PATCH  - <patch> as an integer
    <prefix>_VERSION_STRING - <version> as a C string
    <prefix>_VERSION        - the version as an integer

`<prefix>_VERSION` has `<patch>` in the bottom 8 bits, `<minor>` in the next 8 bits and `<major>` in the remaining bits. Note that `<patch>` and `<minor>` must be less than 256.

If the `PACKAGE_VERSION_FILE` option is used, a simple CMake package version file is created using the `write_basic_package_version_file()` macro provided by CMake. It should be installed in the same location as the Config.cmake file of the library so that it can be found by `find_package()`. If the filename is a relative path, it is interpreted as relative to `CMAKE_CURRENT_BINARY_DIR`. The optional `COMPATIBILITY` option is forwarded to `write_basic_package_version_file()`, and defaults to `AnyNewerVersion`.

If CMake policy CMP0048 is `NEW`, an alternative form of the command is available:

    ecm_setup_version(PROJECT
                      [VARIABLE_PREFIX <prefix>]
                      [SOVERSION <soversion>]
                      [VERSION_HEADER <filename>]
                      [PACKAGE_VERSION_FILE <filename>] )

This will use the version information set by the `project()` command. `VARIABLE_PREFIX` defaults to the project name. Note that `PROJECT` must be the first argument. In all other respects, it behaves like the other form of the command.

Since pre-1.0.0.

`COMPATIBILITY` option available since 1.6.0.