FindPackageHandleStandardArgs¶
This module provides a function intended to be used in Find Modules
implementing find_package(<PackageName>)
calls. It handles the
REQUIRED
, QUIET
and version-related arguments of find_package
.
It also sets the <PackageName>_FOUND
variable. The package is
considered found if all variables listed contain valid results, e.g.
valid filepaths.
-
find_package_handle_standard_args
¶ There are two signatures:
find_package_handle_standard_args(<PackageName> (DEFAULT_MSG|<custom-failure-message>) <required-var>... ) find_package_handle_standard_args(<PackageName> [FOUND_VAR <result-var>] [REQUIRED_VARS <required-var>...] [VERSION_VAR <version-var>] [HANDLE_COMPONENTS] [CONFIG_MODE] [FAIL_MESSAGE <custom-failure-message>] )
The
<PackageName>_FOUND
variable will be set toTRUE
if all the variables<required-var>...
are valid and any optional constraints are satisfied, andFALSE
otherwise. A success or failure message may be displayed based on the results and on whether theREQUIRED
and/orQUIET
option was given to thefind_package()
call.The options are:
(DEFAULT_MSG|<custom-failure-message>)
In the simple signature this specifies the failure message. Use
DEFAULT_MSG
to ask for a default message to be computed (recommended). Not valid in the full signature.FOUND_VAR <result-var>
Obsolete. Specifies either
<PackageName>_FOUND
or<PACKAGENAME>_FOUND
as the result variable. This exists only for compatibility with older versions of CMake and is now ignored. Result variables of both names are always set for compatibility.REQUIRED_VARS <required-var>...
Specify the variables which are required for this package. These may be named in the generated failure message asking the user to set the missing variable values. Therefore these should typically be cache entries such as
FOO_LIBRARY
and not output variables likeFOO_LIBRARIES
.VERSION_VAR <version-var>
Specify the name of a variable that holds the version of the package that has been found. This version will be checked against the (potentially) specified required version given to the
find_package()
call, including itsEXACT
option. The default messages include information about the required version and the version which has been actually found, both if the version is ok or not.HANDLE_COMPONENTS
Enable handling of package components. In this case, the command will report which components have been found and which are missing, and the
<PackageName>_FOUND
variable will be set toFALSE
if any of the required components (i.e. not the ones listed after theOPTIONAL_COMPONENTS
option offind_package()
) are missing.CONFIG_MODE
Specify that the calling find module is a wrapper around a call to
find_package(<PackageName> NO_MODULE)
. This implies aVERSION_VAR
value of<PackageName>_VERSION
. The command will automatically check whether the package configuration file was found.FAIL_MESSAGE <custom-failure-message>
Specify a custom failure message instead of using the default generated message. Not recommended.
Example for the simple signature:
find_package_handle_standard_args(LibXml2 DEFAULT_MSG
LIBXML2_LIBRARY LIBXML2_INCLUDE_DIR)
The LibXml2
package is considered to be found if both
LIBXML2_LIBRARY
and LIBXML2_INCLUDE_DIR
are valid.
Then also LibXml2_FOUND
is set to TRUE
. If it is not found
and REQUIRED
was used, it fails with a
message(FATAL_ERROR)
, independent whether QUIET
was
used or not. If it is found, success will be reported, including
the content of the first <required-var>
. On repeated CMake runs,
the same message will not be printed again.
Example for the full signature:
find_package_handle_standard_args(LibArchive
REQUIRED_VARS LibArchive_LIBRARY LibArchive_INCLUDE_DIR
VERSION_VAR LibArchive_VERSION)
In this case, the LibArchive
package is considered to be found if
both LibArchive_LIBRARY
and LibArchive_INCLUDE_DIR
are valid.
Also the version of LibArchive
will be checked by using the version
contained in LibArchive_VERSION
. Since no FAIL_MESSAGE
is given,
the default messages will be printed.
Another example for the full signature:
find_package(Automoc4 QUIET NO_MODULE HINTS /opt/automoc4)
find_package_handle_standard_args(Automoc4 CONFIG_MODE)
In this case, a FindAutmoc4.cmake
module wraps a call to
find_package(Automoc4 NO_MODULE)
and adds an additional search
directory for automoc4
. Then the call to
find_package_handle_standard_args
produces a proper success/failure
message.