a pkg-config module for CMake


pkg_check_modules(<PREFIX> [REQUIRED] [QUIET] <MODULE> [<MODULE>]*)
  checks for all the given modules
pkg_search_module(<PREFIX> [REQUIRED] [QUIET] <MODULE> [<MODULE>]*)
  checks for given modules and uses the first working one

When the ‘REQUIRED’ argument was set, macros will fail with an error when module(s) could not be found

When the ‘QUIET’ argument is set, no status messages will be printed.

It sets the following variables:

PKG_CONFIG_FOUND          ... if pkg-config executable was found
PKG_CONFIG_EXECUTABLE     ... pathname of the pkg-config program
PKG_CONFIG_VERSION_STRING ... the version of the pkg-config program found
                              (since CMake 2.8.8)

For the following variables two sets of values exist; first one is the common one and has the given PREFIX. The second set contains flags which are given out when pkgconfig was called with the ‘–static’ option.

<XPREFIX>_FOUND          ... set to 1 if module(s) exist
<XPREFIX>_LIBRARIES      ... only the libraries (w/o the '-l')
<XPREFIX>_LIBRARY_DIRS   ... the paths of the libraries (w/o the '-L')
<XPREFIX>_LDFLAGS        ... all required linker flags
<XPREFIX>_LDFLAGS_OTHER  ... all other linker flags
<XPREFIX>_INCLUDE_DIRS   ... the '-I' preprocessor flags (w/o the '-I')
<XPREFIX>_CFLAGS         ... all required cflags
<XPREFIX>_CFLAGS_OTHER   ... the other compiler flags
<XPREFIX> = <PREFIX>        for common case
<XPREFIX> = <PREFIX>_STATIC for static linking

There are some special variables whose prefix depends on the count of given modules. When there is only one module, <PREFIX> stays unchanged. When there are multiple modules, the prefix will be changed to <PREFIX>_<MODNAME>:

<XPREFIX>_VERSION    ... version of the module
<XPREFIX>_PREFIX     ... prefix-directory of the module
<XPREFIX>_INCLUDEDIR ... include-dir of the module
<XPREFIX>_LIBDIR     ... lib-dir of the module
<XPREFIX> = <PREFIX>  when |MODULES| == 1, else

A <MODULE> parameter can have the following formats:

{MODNAME}            ... matches any version
{MODNAME}>={VERSION} ... at least version <VERSION> is required
{MODNAME}={VERSION}  ... exactly version <VERSION> is required
{MODNAME}<={VERSION} ... modules must not be newer than <VERSION>


pkg_check_modules (GLIB2   glib-2.0)
pkg_check_modules (GLIB2   glib-2.0>=2.10)
  requires at least version 2.10 of glib2 and defines e.g.
pkg_check_modules (FOO     glib-2.0>=2.10 gtk+-2.0)
  requires both glib2 and gtk2, and defines e.g.
pkg_check_modules (XRENDER REQUIRED xrender)
  defines e.g.:
pkg_search_module (BAR     libxml-2.0 libxml2 libxml>=2)