FindPkgConfig

A pkg-config module for CMake.

Finds the pkg-config executable and adds the pkg_get_variable(), pkg_check_modules() and pkg_search_module() commands. The following variables will also be set:

PKG_CONFIG_FOUND

True if a pkg-config executable was found.

PKG_CONFIG_VERSION_STRING

在 2.8.8 版被加入.

The version of pkg-config that was found.

PKG_CONFIG_EXECUTABLE

The pathname of the pkg-config program.

PKG_CONFIG_ARGN

在 3.22 版被加入.

A list of arguments to pass to pkg-config.

Both PKG_CONFIG_EXECUTABLE and PKG_CONFIG_ARGN are initialized by the module, but may be overridden by the user. See Variables Affecting Behavior for how these variables are initialized.

pkg_check_modules

Checks for all the given modules, setting a variety of result variables in the calling scope.

pkg_check_modules(<prefix>
                  [REQUIRED] [QUIET]
                  [NO_CMAKE_PATH]
                  [NO_CMAKE_ENVIRONMENT_PATH]
                  [IMPORTED_TARGET [GLOBAL]]
                  <moduleSpec> [<moduleSpec>...])

When the REQUIRED argument is given, the command will fail with an error if module(s) could not be found.

When the QUIET argument is given, no status messages will be printed.

在 3.3 版被加入: The CMAKE_PREFIX_PATH, CMAKE_FRAMEWORK_PATH, and CMAKE_APPBUNDLE_PATH cache and environment variables will be added to the pkg-config search path. The NO_CMAKE_PATH and NO_CMAKE_ENVIRONMENT_PATH arguments disable this behavior for the cache variables and environment variables respectively. The PKG_CONFIG_USE_CMAKE_PREFIX_PATH variable set to FALSE disables this behavior globally.

在 3.7 版被加入: The IMPORTED_TARGET argument will create an imported target named PkgConfig::<prefix> that can be passed directly as an argument to target_link_libraries().

在 3.13 版被加入: The GLOBAL argument will make the imported target available in global scope.

在 3.15 版被加入: Non-library linker options reported by pkg-config are stored in the INTERFACE_LINK_OPTIONS target property.

在 3.18 版的變更: Include directories specified with -isystem are stored in the INTERFACE_INCLUDE_DIRECTORIES target property. Previous versions of CMake left them in the INTERFACE_COMPILE_OPTIONS property.

Each <moduleSpec> can be either a bare module name or it can be a module name with a version constraint (operators =, <, >, <= and >= are supported). The following are examples for a module named foo with various constraints:

• foo matches any version.

• foo<2 only matches versions before 2.

• foo>=3.1 matches any version from 3.1 or later.

• foo=1.2.3 requires that foo must be exactly version 1.2.3.

The following variables may be set upon return. Two sets of values exist: One for the common case (<XXX> = <prefix>) and another for the information pkg-config provides when called with the --static option (<XXX> = <prefix>_STATIC).

<XXX>_FOUND

set to 1 if module(s) exist

<XXX>_LIBRARIES

only the libraries (without the '-l')

<XXX>_LINK_LIBRARIES

the libraries and their absolute paths

<XXX>_LIBRARY_DIRS

the paths of the libraries (without the '-L')

<XXX>_LDFLAGS

all required linker flags

<XXX>_LDFLAGS_OTHER

all other linker flags

<XXX>_INCLUDE_DIRS

the '-I' preprocessor flags (without the '-I')

<XXX>_CFLAGS

all required cflags

<XXX>_CFLAGS_OTHER

the other compiler flags

All but <XXX>_FOUND may be a ;-list if the associated variable returned from pkg-config has multiple values.

在 3.18 版的變更: Include directories specified with -isystem are stored in the <XXX>_INCLUDE_DIRS variable. Previous versions of CMake left them in <XXX>_CFLAGS_OTHER.

There are some special variables whose prefix depends on the number of <moduleSpec> given. When there is only one <moduleSpec>, <YYY> will simply be <prefix>, but if two or more <moduleSpec> items are given, <YYY> will be <prefix>_<moduleName>.

<YYY>_VERSION

version of the module

<YYY>_PREFIX

prefix directory of the module

<YYY>_INCLUDEDIR

include directory of the module

<YYY>_LIBDIR

lib directory of the module

在 3.8 版的變更: For any given <prefix>, pkg_check_modules() can be called multiple times with different parameters. Previous versions of CMake cached and returned the first successful result.

在 3.16 版的變更: If a full path to the found library can't be determined, but it's still visible to the linker, pass it through as -l<name>. Previous versions of CMake failed in this case.

Examples:

pkg_check_modules (GLIB2 glib-2.0)

Looks for any version of glib2. If found, the output variable GLIB2_VERSION will hold the actual version found.

pkg_check_modules (GLIB2 glib-2.0>=2.10)

Looks for at least version 2.10 of glib2. If found, the output variable GLIB2_VERSION will hold the actual version found.

pkg_check_modules (FOO glib-2.0>=2.10 gtk+-2.0)

Looks for both glib2-2.0 (at least version 2.10) and any version of gtk2+-2.0. Only if both are found will FOO be considered found. The FOO_glib-2.0_VERSION and FOO_gtk+-2.0_VERSION variables will be set to their respective found module versions.

pkg_check_modules (XRENDER REQUIRED xrender)

Requires any version of xrender. Example output variables set by a successful call:

XRENDER_LIBRARIES=Xrender;X11
XRENDER_STATIC_LIBRARIES=Xrender;X11;pthread;Xau;Xdmcp

pkg_search_module

The behavior of this command is the same as pkg_check_modules(), except that rather than checking for all the specified modules, it searches for just the first successful match.

pkg_search_module(<prefix>
                  [REQUIRED] [QUIET]
                  [NO_CMAKE_PATH]
                  [NO_CMAKE_ENVIRONMENT_PATH]
                  [IMPORTED_TARGET [GLOBAL]]
                  <moduleSpec> [<moduleSpec>...])

在 3.16 版被加入: If a module is found, the <prefix>_MODULE_NAME variable will contain the name of the matching module. This variable can be used if you need to run pkg_get_variable().

Example:

pkg_search_module (BAR libxml-2.0 libxml2 libxml>=2)

pkg_get_variable

在 3.4 版被加入.

Retrieves the value of a pkg-config variable varName and stores it in the result variable resultVar in the calling scope.

pkg_get_variable(<resultVar> <moduleName> <varName>
                 [DEFINE_VARIABLES <key>=<value>...])

If pkg-config returns multiple values for the specified variable, resultVar will contain a ;-list.

Options:

DEFINE_VARIABLES <key>=<value>...

在 3.28 版被加入.

Specify key-value pairs to redefine variables affecting the variable retrieved with pkg-config.

For example:

pkg_get_variable(GI_GIRDIR gobject-introspection-1.0 girdir)

Variables Affecting Behavior

PKG_CONFIG_EXECUTABLE

This cache variable can be set to the path of the pkg-config executable. find_program() is called internally by the module with this variable.

在 3.1 版被加入: The PKG_CONFIG environment variable can be used as a hint if PKG_CONFIG_EXECUTABLE has not yet been set.

在 3.22 版的變更: If the PKG_CONFIG environment variable is set, only the first argument is taken from it when using it as a hint.

PKG_CONFIG_ARGN

在 3.22 版被加入.

This cache variable can be set to a list of arguments to additionally pass to pkg-config if needed. If not provided, it will be initialized from the PKG_CONFIG environment variable, if set. The first argument in that environment variable is assumed to be the pkg-config program, while all remaining arguments after that are used to initialize PKG_CONFIG_ARGN. If no such environment variable is defined, PKG_CONFIG_ARGN is initialized to an empty string. The module does not update the variable once it has been set in the cache.

PKG_CONFIG_USE_CMAKE_PREFIX_PATH

在 3.1 版被加入.

Specifies whether pkg_check_modules() and pkg_search_module() should add the paths in the CMAKE_PREFIX_PATH, CMAKE_FRAMEWORK_PATH and CMAKE_APPBUNDLE_PATH cache and environment variables to the pkg-config search path.

If this variable is not set, this behavior is enabled by default if CMAKE_MINIMUM_REQUIRED_VERSION is 3.1 or later, disabled otherwise.