CMake 2.6.4 Docs

From KitwarePublic

cmake version 2.6-patch 4
------------------------------------------------------------------------------
Name

cmake - Cross-Platform Makefile Generator.

------------------------------------------------------------------------------
Usage

cmake [options] <path-to-source>
cmake [options] <path-to-existing-build>

------------------------------------------------------------------------------
Description

The "cmake" executable is the CMake command-line interface. It may be used
to configure projects in scripts. Project configuration settings may be
specified on the command line with the -D option. The -i option will cause
cmake to interactively prompt for such settings.

CMake is a cross-platform build system generator. Projects specify their
build process with platform-independent CMake listfiles included in each
directory of a source tree with the name CMakeLists.txt. Users build a
project by using CMake to generate a build system for a native tool on their
platform.

------------------------------------------------------------------------------
Options

-C <initial-cache>
Pre-load a script to populate the cache.

When cmake is first run in an empty build tree, it creates a
CMakeCache.txt file and populates it with customizable settings for
the project. This option may be used to specify a file from which to
load cache entries before the first pass through the project's cmake
listfiles. The loaded entries take priority over the project's
default values. The given file should be a CMake script containing
SET commands that use the CACHE option, not a cache-format file.

-D <var>:<type>=<value>
Create a cmake cache entry.

When cmake is first run in an empty build tree, it creates a
CMakeCache.txt file and populates it with customizable settings for
the project. This option may be used to specify a setting that takes
priority over the project's default value. The option may be repeated
for as many cache entries as desired.

-U <globbing_expr>
Remove matching entries from CMake cache.

This option may be used to remove one or more variables from the
CMakeCache.txt file, globbing expressions using * and ? are supported.
The option may be repeated for as many cache entries as desired.

Use with care, you can make your CMakeCache.txt non-working.

-G <generator-name>
Specify a makefile generator.

CMake may support multiple native build systems on certain platforms.
A makefile generator is responsible for generating a particular build
system. Possible generator names are specified in the Generators
section.

-Wno-dev
Suppress developer warnings.

Suppress warnings that are meant for the author of the CMakeLists.txt
files.

-Wdev
Enable developer warnings.

Enable warnings that are meant for the author of the CMakeLists.txt
files.

-E
CMake command mode.

For true platform independence, CMake provides a list of commands that
can be used on all systems. Run with -E help for the usage
information. Commands availble are: chdir, copy, copy_if_different
copy_directory, compare_files, echo, echo_append, environment,
make_directory, md5sum, remove_directory, remove, tar, time, touch,
touch_nocreate, write_regv, delete_regv, comspec, create_symlink.

-i
Run in wizard mode.

Wizard mode runs cmake interactively without a GUI. The user is
prompted to answer questions about the project configuration. The
answers are used to set cmake cache values.

-L[A][H]
List non-advanced cached variables.

List cache variables will run CMake and list all the variables from
the CMake cache that are not marked as INTERNAL or ADVANCED. This
will effectively display current CMake settings, which can be then
changed with -D option. Changing some of the variable may result in
more variables being created. If A is specified, then it will display
also advanced variables. If H is specified, it will also display help
for each variable.

-N
View mode only.

Only load the cache. Do not actually run configure and generate
steps.

-P <file>
Process script mode.

Process the given cmake file as a script written in the CMake
language. No configure or generate step is performed and the cache is
not modified. If variables are defined using -D, this must be done
before the -P argument.

--graphviz=[file]
Generate graphviz of dependencies.

Generate a graphviz input file that will contain all the library and
executable dependencies in the project.

--system-information [file]
Dump information about this system.

Dump a wide range of information about the current system. If run
from the top of a binary tree for a CMake project it will dump
additional information such as the cache, log files etc.

--debug-trycompile
Do not delete the try compile directories..

Do not delete the files and directories created for try_compile calls.
This is useful in debugging failed try_compiles. It may however
change the results of the try-compiles as old junk from a previous
try-compile may cause a different test to either pass or fail
incorrectly. This option is best used for one try-compile at a time,
and only when debugging.

--debug-output
Put cmake in a debug mode.

Print extra stuff during the cmake run like stack traces with
message(send_error ) calls.

--trace
Put cmake in trace mode.

Print a trace of all calls made and from where with message(send_error
) calls.

--help-command cmd [file]
Print help for a single command and exit.

Full documentation specific to the given command is displayed. If a
file is specified, the documentation is written into and the output
format is determined depending on the filename suffix. Supported are
man page, HTML, DocBook and plain text.

--help-command-list [file]
List available listfile commands and exit.

The list contains all commands for which help may be obtained by using
the --help-command argument followed by a command name. If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-commands [file]
Print help for all commands and exit.

Full documentation specific for all current command is displayed.If a
file is specified, the documentation is written into and the output
format is determined depending on the filename suffix. Supported are
man page, HTML, DocBook and plain text.

--help-compatcommands [file]
Print help for compatibility commands.

Full documentation specific for all compatibility commands is
displayed.If a file is specified, the documentation is written into
and the output format is determined depending on the filename suffix.
Supported are man page, HTML, DocBook and plain text.

--help-module module [file]
Print help for a single module and exit.

Full documentation specific to the given module is displayed.If a file
is specified, the documentation is written into and the output format
is determined depending on the filename suffix. Supported are man
page, HTML, DocBook and plain text.

--help-module-list [file]
List available modules and exit.

The list contains all modules for which help may be obtained by using
the --help-module argument followed by a module name. If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-modules [file]
Print help for all modules and exit.

Full documentation for all modules is displayed. If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-custom-modules [file]
Print help for all custom modules and exit.

Full documentation for all custom modules is displayed. If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-policy cmp [file]
Print help for a single policy and exit.

Full documentation specific to the given policy is displayed.If a file
is specified, the documentation is written into and the output format
is determined depending on the filename suffix. Supported are man
page, HTML, DocBook and plain text.

--help-policies [file]
Print help for all policies and exit.

Full documentation for all policies is displayed.If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-property prop [file]
Print help for a single property and exit.

Full documentation specific to the given property is displayed.If a
file is specified, the documentation is written into and the output
format is determined depending on the filename suffix. Supported are
man page, HTML, DocBook and plain text.

--help-property-list [file]
List available properties and exit.

The list contains all properties for which help may be obtained by
using the --help-property argument followed by a property name. If a
file is specified, the help is written into it.If a file is specified,
the documentation is written into and the output format is determined
depending on the filename suffix. Supported are man page, HTML,
DocBook and plain text.

--help-properties [file]
Print help for all properties and exit.

Full documentation for all properties is displayed.If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--help-variable var [file]
Print help for a single variable and exit.

Full documentation specific to the given variable is displayed.If a
file is specified, the documentation is written into and the output
format is determined depending on the filename suffix. Supported are
man page, HTML, DocBook and plain text.

--help-variable-list [file]
List documented variables and exit.

The list contains all variables for which help may be obtained by
using the --help-variable argument followed by a variable name. If a
file is specified, the help is written into it.If a file is specified,
the documentation is written into and the output format is determined
depending on the filename suffix. Supported are man page, HTML,
DocBook and plain text.

--help-variables [file]
Print help for all variables and exit.

Full documentation for all variables is displayed.If a file is
specified, the documentation is written into and the output format is
determined depending on the filename suffix. Supported are man page,
HTML, DocBook and plain text.

--copyright [file]
Print the CMake copyright and exit.

If a file is specified, the copyright is written into it.

--help
Print usage information and exit.

Usage describes the basic command line interface and its options.

--help-full [file]
Print full help and exit.

Full help displays most of the documentation provided by the UNIX man
page. It is provided for use on non-UNIX platforms, but is also
convenient if the man page is not installed. If a file is specified,
the help is written into it.

--help-html [file]
Print full help in HTML format.

This option is used by CMake authors to help produce web pages. If a
file is specified, the help is written into it.

--help-man [file]
Print full help as a UNIX man page and exit.

This option is used by the cmake build to generate the UNIX man page.
If a file is specified, the help is written into it.

--version [file]
Show program name/version banner and exit.

If a file is specified, the version is written into it.

------------------------------------------------------------------------------
Generators

The following generators are available on this platform:

Unix Makefiles
Generates standard UNIX makefiles.

A hierarchy of UNIX makefiles is generated into the build tree. Any
standard UNIX-style make program can build the project through the
default make target. A "make install" target is also provided.

CodeBlocks - Unix Makefiles
Generates CodeBlocks project files.

Project files for CodeBlocks will be created in the top directory and
in every subdirectory which features a CMakeLists.txt file containing
a PROJECT() call. Additionally a hierarchy of makefiles is generated
into the build tree. The appropriate make program can build the
project through the default make target. A "make install" target is
also provided.

Eclipse CDT4 - Unix Makefiles
Generates Eclipse CDT 4.0 project files.

Project files for Eclipse will be created in the top directory and
will have a linked resource to every subdirectory which features a
CMakeLists.txt file containing a PROJECT() call.Additionally a
hierarchy of makefiles is generated into the build tree. The
appropriate make program can build the project through the default
make target. A "make install" target is also provided.

KDevelop3
Generates KDevelop 3 project files.

Project files for KDevelop 3 will be created in the top directory and
in every subdirectory which features a CMakeLists.txt file containing
a PROJECT() call. If you change the settings using KDevelop cmake
will try its best to keep your changes when regenerating the project
files. Additionally a hierarchy of UNIX makefiles is generated into
the build tree. Any standard UNIX-style make program can build the
project through the default make target. A "make install" target is
also provided.

KDevelop3 - Unix Makefiles
Generates KDevelop 3 project files.

Project files for KDevelop 3 will be created in the top directory and
in every subdirectory which features a CMakeLists.txt file containing
a PROJECT() call. If you change the settings using KDevelop cmake
will try its best to keep your changes when regenerating the project
files. Additionally a hierarchy of UNIX makefiles is generated into
the build tree. Any standard UNIX-style make program can build the
project through the default make target. A "make install" target is
also provided.

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Commands

add_custom_command
Add a custom build rule to the generated build system.

There are two main signatures for add_custom_command The first
signature is for adding a custom command to produce an output.

add_custom_command(OUTPUT output1 [output2 ...]
COMMAND command1 [ARGS] [args1...]
[COMMAND command2 [ARGS] [args2...] ...]
[MAIN_DEPENDENCY depend]
[DEPENDS [depends...]]
[IMPLICIT_DEPENDS <lang1> depend1 ...]
[WORKING_DIRECTORY dir]
[COMMENT comment] [VERBATIM] [APPEND])

This defines a command to generate specified OUTPUT file(s). A target
created in the same directory (CMakeLists.txt file) that specifies any
output of the custom command as a source file is given a rule to
generate the file using the command at build time. If an output name
is a relative path it will be interpreted relative to the build tree
directory corresponding to the current source directory. Note that
MAIN_DEPENDENCY is completely optional and is used as a suggestion to
visual studio about where to hang the custom command. In makefile
terms this creates a new target in the following form:

OUTPUT: MAIN_DEPENDENCY DEPENDS
COMMAND

If more than one command is specified they will be executed in order.
The optional ARGS argument is for backward compatibility and will be
ignored.

The second signature adds a custom command to a target such as a
library or executable. This is useful for performing an operation
before or after building the target. The command becomes part of the
target and will only execute when the target itself is built. If the
target is already built, the command will not execute.

add_custom_command(TARGET target
PRE_BUILD | PRE_LINK | POST_BUILD
COMMAND command1 [ARGS] [args1...]
[COMMAND command2 [ARGS] [args2...] ...]
[WORKING_DIRECTORY dir]
[COMMENT comment] [VERBATIM])

This defines a new command that will be associated with building the
specified target. When the command will happen is determined by which
of the following is specified:

PRE_BUILD - run before all other dependencies
PRE_LINK - run after other dependencies
POST_BUILD - run after the target has been built

Note that the PRE_BUILD option is only supported on Visual Studio 7 or
later. For all other generators PRE_BUILD will be treated as
PRE_LINK.

If WORKING_DIRECTORY is specified the command will be executed in the
directory given. If COMMENT is set, the value will be displayed as a
message before the commands are executed at build time. If APPEND is
specified the COMMAND and DEPENDS option values are appended to the
custom command for the first output specified. There must have
already been a previous call to this command with the same output.
The COMMENT, WORKING_DIRECTORY, and MAIN_DEPENDENCY options are
currently ignored when APPEND is given, but may be used in the future.

If VERBATIM is given then all arguments to the commands will be
escaped properly for the build tool so that the invoked command
receives each argument unchanged. Note that one level of escapes is
still used by the CMake language processor before add_custom_command
even sees the arguments. Use of VERBATIM is recommended as it enables
correct behavior. When VERBATIM is not given the behavior is platform
specific because there is no protection of tool-specific special
characters.

If the output of the custom command is not actually created as a file
on disk it should be marked as SYMBOLIC with
SET_SOURCE_FILES_PROPERTIES.

The IMPLICIT_DEPENDS option requests scanning of implicit dependencies
of an input file. The language given specifies the programming
language whose corresponding dependency scanner should be used.
Currently only C and CXX language scanners are supported.
Dependencies discovered from the scanning are added to those of the
custom command at build time. Note that the IMPLICIT_DEPENDS option
is currently supported only for Makefile generators and will be
ignored by other generators.

If COMMAND specifies an executable target (created by ADD_EXECUTABLE)
it will automatically be replaced by the location of the executable
created at build time. Additionally a target-level dependency will be
added so that the executable target will be built before any target
using this custom command. However this does NOT add a file-level
dependency that would cause the custom command to re-run whenever the
executable is recompiled.

The DEPENDS option specifies files on which the command depends. If
any dependency is an OUTPUT of another custom command in the same
directory (CMakeLists.txt file) CMake automatically brings the other
custom command into the target in which this command is built. If
DEPENDS specifies any target (created by an ADD_* command) a
target-level dependency is created to make sure the target is built
before any target using this custom command. Additionally, if the
target is an executable or library a file-level dependency is created
to cause the custom command to re-run whenever the target is
recompiled.

add_custom_target
Add a target with no output so it will always be built.

add_custom_target(Name [ALL] [command1 [args1...]]
[COMMAND command2 [args2...] ...]
[DEPENDS depend depend depend ... ]
[WORKING_DIRECTORY dir]
[COMMENT comment] [VERBATIM]
[SOURCES src1 [src2...]])

Adds a target with the given name that executes the given commands.
The target has no output file and is ALWAYS CONSIDERED OUT OF DATE
even if the commands try to create a file with the name of the target.
Use ADD_CUSTOM_COMMAND to generate a file with dependencies. By
default nothing depends on the custom target. Use ADD_DEPENDENCIES to
add dependencies to or from other targets. If the ALL option is
specified it indicates that this target should be added to the default
build target so that it will be run every time (the command cannot be
called ALL). The command and arguments are optional and if not
specified an empty target will be created. If WORKING_DIRECTORY is
set, then the command will be run in that directory. If COMMENT is
set, the value will be displayed as a message before the commands are
executed at build time. Dependencies listed with the DEPENDS argument
may reference files and outputs of custom commands created with
add_custom_command() in the same directory (CMakeLists.txt file).

If VERBATIM is given then all arguments to the commands will be
escaped properly for the build tool so that the invoked command
receives each argument unchanged. Note that one level of escapes is
still used by the CMake language processor before add_custom_target
even sees the arguments. Use of VERBATIM is recommended as it enables
correct behavior. When VERBATIM is not given the behavior is platform
specific because there is no protection of tool-specific special
characters.

The SOURCES option specifies additional source files to be included in
the custom target. Specified source files will be added to IDE
project files for convenience in editing even if they have not build
rules.

add_definitions
Adds -D define flags to the compilation of source files.

add_definitions(-DFOO -DBAR ...)

Adds flags to the compiler command line for sources in the current
directory and below. This command can be used to add any flags, but
it was originally intended to add preprocessor definitions. Flags
beginning in -D or /D that look like preprocessor definitions are
automatically added to the COMPILE_DEFINITIONS property for the
current directory. Definitions with non-trival values may be left in
the set of flags instead of being converted for reasons of backwards
compatibility. See documentation of the directory, target, and source
file COMPILE_DEFINITIONS properties for details on adding preprocessor
definitions to specific scopes and configurations.

add_dependencies
Add a dependency between top-level targets.

add_dependencies(target-name depend-target1
depend-target2 ...)

Make a top-level target depend on other top-level targets. A
top-level target is one created by ADD_EXECUTABLE, ADD_LIBRARY, or
ADD_CUSTOM_TARGET. Adding dependencies with this command can be used
to make sure one target is built before another target. See the
DEPENDS option of ADD_CUSTOM_TARGET and ADD_CUSTOM_COMMAND for adding
file-level dependencies in custom rules. See the OBJECT_DEPENDS
option in SET_SOURCE_FILES_PROPERTIES to add file-level dependencies
to object files.

add_executable
Add an executable to the project using the specified source files.

add_executable(<name> [WIN32] [MACOSX_BUNDLE] [EXCLUDE_FROM_ALL]
source1 source2 ... sourceN)

Adds an executable target called <name> to be built from the source
files listed in the command invocation. The <name> corresponds to the
logical target name and must be globally unique within a project. The
actual file name of the executable built is constructed based on
conventions of the native platform (such as <name>.exe or just
<name>).

By default the executable file will be created in the build tree
directory corresponding to the source tree directory in which the
command was invoked. See documentation of the
RUNTIME_OUTPUT_DIRECTORY target property to change this location. See
documentation of the OUTPUT_NAME target property to change the <name>
part of the final file name.

If WIN32 is given the property WIN32_EXECUTABLE will be set on the
target created. See documentation of that target property for
details.

If MACOSX_BUNDLE is given the corresponding property will be set on
the created target. See documentation of the MACOSX_BUNDLE target
property for details.

If EXCLUDE_FROM_ALL is given the corresponding property will be set on
the created target. See documentation of the EXCLUDE_FROM_ALL target
property for details.

The add_executable command can also create IMPORTED executable targets
using this signature:

add_executable(<name> IMPORTED)

An IMPORTED executable target references an executable file located
outside the project. No rules are generated to build it. The target
name has scope in the directory in which it is created and below. It
may be referenced like any target built within the project. IMPORTED
executables are useful for convenient reference from commands like
add_custom_command. Details about the imported executable are
specified by setting properties whose names begin in "IMPORTED_". The
most important such property is IMPORTED_LOCATION (and its
per-configuration version IMPORTED_LOCATION_<CONFIG>) which specifies
the location of the main executable file on disk. See documentation
of the IMPORTED_* properties for more information.

add_library
Add a library to the project using the specified source files.

add_library(<name> [STATIC | SHARED | MODULE] [EXCLUDE_FROM_ALL]
source1 source2 ... sourceN)

Adds a library target called <name> to be built from the source files
listed in the command invocation. The <name> corresponds to the
logical target name and must be globally unique within a project. The
actual file name of the library built is constructed based on
conventions of the native platform (such as lib<name>.a or
<name>.lib).

STATIC, SHARED, or MODULE may be given to specify the type of library
to be created. STATIC libraries are archives of object files for use
when linking other targets. SHARED libraries are linked dynamically
and loaded at runtime. MODULE libraries are plugins that are not
linked into other targets but may be loaded dynamically at runtime
using dlopen-like functionality. If no type is given explicitly the
type is STATIC or SHARED based on whether the current value of the
variable BUILD_SHARED_LIBS is true.

By default the library file will be created in the build tree
directory corresponding to the source tree directory in which the
command was invoked. See documentation of the
ARCHIVE_OUTPUT_DIRECTORY, LIBRARY_OUTPUT_DIRECTORY, and
RUNTIME_OUTPUT_DIRECTORY target properties to change this location.
See documentation of the OUTPUT_NAME target property to change the
<name> part of the final file name.

If EXCLUDE_FROM_ALL is given the corresponding property will be set on
the created target. See documentation of the EXCLUDE_FROM_ALL target
property for details.

The add_library command can also create IMPORTED library targets using
this signature:

add_library(<name> <SHARED|STATIC|MODULE|UNKNOWN> IMPORTED)

An IMPORTED library target references a library file located outside
the project. No rules are generated to build it. The target name has
scope in the directory in which it is created and below. It may be
referenced like any target built within the project. IMPORTED
libraries are useful for convenient reference from commands like
target_link_libraries. Details about the imported library are
specified by setting properties whose names begin in "IMPORTED_". The
most important such property is IMPORTED_LOCATION (and its
per-configuration version IMPORTED_LOCATION_<CONFIG>) which specifies
the location of the main library file on disk. See documentation of
the IMPORTED_* properties for more information.

add_subdirectory
Add a subdirectory to the build.

add_subdirectory(source_dir [binary_dir]
[EXCLUDE_FROM_ALL])

Add a subdirectory to the build. The source_dir specifies the
directory in which the source CmakeLists.txt and code files are
located. If it is a relative path it will be evaluated with respect
to the current directory (the typical usage), but it may also be an
absolute path. The binary_dir specifies the directory in which to
place the output files. If it is a relative path it will be evaluated
with respect to the current output directory, but it may also be an
absolute path. If binary_dir is not specified, the value of
source_dir, before expanding any relative path, will be used (the
typical usage). The CMakeLists.txt file in the specified source
directory will be processed immediately by CMake before processing in
the current input file continues beyond this command.

If the EXCLUDE_FROM_ALL argument is provided then targets in the
subdirectory will not be included in the ALL target of the parent
directory by default, and will be excluded from IDE project files.
Users must explicitly build targets in the subdirectory. This is
meant for use when the subdirectory contains a separate part of the
project that is useful but not necessary, such as a set of examples.
Typically the subdirectory should contain its own project() command
invocation so that a full build system will be generated in the
subdirectory (such as a VS IDE solution file). Note that inter-target
dependencies supercede this exclusion. If a target built by the
parent project depends on a target in the subdirectory, the dependee
target will be included in the parent project build system to satisfy
the dependency.

add_test
Add a test to the project with the specified arguments.

add_test(testname Exename arg1 arg2 ...)

If the ENABLE_TESTING command has been run, this command adds a test
target to the current directory. If ENABLE_TESTING has not been run,
this command does nothing. The tests are run by the testing subsystem
by executing Exename with the specified arguments. Exename can be
either an executable built by this project or an arbitrary executable
on the system (like tclsh). The test will be run with the current
working directory set to the CMakeList.txt files corresponding
directory in the binary tree.

aux_source_directory
Find all source files in a directory.

aux_source_directory(<dir> <variable>)

Collects the names of all the source files in the specified directory
and stores the list in the <variable> provided. This command is
intended to be used by projects that use explicit template
instantiation. Template instantiation files can be stored in a
"Templates" subdirectory and collected automatically using this
command to avoid manually listing all instantiations.

It is tempting to use this command to avoid writing the list of source
files for a library or executable target. While this seems to work,
there is no way for CMake to generate a build system that knows when a
new source file has been added. Normally the generated build system
knows when it needs to rerun CMake because the CMakeLists.txt file is
modified to add a new source. When the source is just added to the
directory without modifying this file, one would have to manually
rerun CMake to generate a build system incorporating the new file.

break
Break from an enclosing foreach or while loop.

break()

Breaks from an enclosing foreach loop or while loop

build_command
Get the command line that will build this project.

build_command(<variable> <makecommand>)

Sets the given <variable> to a string containing the command that will
build this project from the root of the build tree using the build
tool given by <makecommand>. <makecommand> should be msdev, nmake,
make or one of the end user build tools. This is useful for
configuring testing systems.

cmake_minimum_required
Set the minimum required version of cmake for a project.

cmake_minimum_required(VERSION major[.minor[.patch]]
[FATAL_ERROR])

If the current version of CMake is lower than that required it will
stop processing the project and report an error. When a version
higher than 2.4 is specified the command implicitly invokes

cmake_policy(VERSION major[.minor[.patch]])

which sets the cmake policy version level to the version specified.
When version 2.4 or lower is given the command implicitly invokes

cmake_policy(VERSION 2.4)

which enables compatibility features for CMake 2.4 and lower.

The FATAL_ERROR option is accepted but ignored by CMake 2.6 and
higher. It should be specified so CMake versions 2.4 and lower fail
with an error instead of just a warning.

cmake_policy
Manage CMake Policy settings.

As CMake evolves it is sometimes necessary to change existing behavior
in order to fix bugs or improve implementations of existing features.
The CMake Policy mechanism is designed to help keep existing projects
building as new versions of CMake introduce changes in behavior. Each
new policy (behavioral change) is given an identifier of the form
"CMP<NNNN>" where "<NNNN>" is an integer index. Documentation
associated with each policy describes the OLD and NEW behavior and the
reason the policy was introduced. Projects may set each policy to
select the desired behavior. When CMake needs to know which behavior
to use it checks for a setting specified by the project. If no
setting is available the OLD behavior is assumed and a warning is
produced requesting that the policy be set.

The cmake_policy command is used to set policies to OLD or NEW
behavior. While setting policies individually is supported, we
encourage projects to set policies based on CMake versions.

cmake_policy(VERSION major.minor[.patch])

Specify that the current CMake list file is written for the given
version of CMake. All policies introduced in the specified version or
earlier will be set to use NEW behavior. All policies introduced
after the specified version will be reset to use OLD behavior with a
warning. This effectively requests behavior preferred as of a given
CMake version and tells newer CMake versions to warn about their new
policies. The policy version specified must be at least 2.4 or the
command will report an error. In order to get compatibility features
supporting versions earlier than 2.4 see documentation of policy
CMP0001.

cmake_policy(SET CMP<NNNN> NEW)
cmake_policy(SET CMP<NNNN> OLD)

Tell CMake to use the OLD or NEW behavior for a given policy.
Projects depending on the old behavior of a given policy may silence a
policy warning by setting the policy state to OLD. Alternatively one
may fix the project to work with the new behavior and set the policy
state to NEW.

cmake_policy(GET CMP<NNNN> <variable>)

Check whether a given policy is set to OLD or NEW behavior. The
output variable value will be "OLD" or "NEW" if the policy is set, and
empty otherwise.

CMake keeps policy settings on a stack, so changes made by the
cmake_policy command affect only the top of the stack. A new entry on
the policy stack is managed automatically for each subdirectory to
protect its parents and siblings. CMake also manages a new entry for
scripts loaded by include() and find_package() commands except when
invoked with the NO_POLICY_SCOPE option (see also policy CMP0011).
The cmake_policy command provides an interface to manage custom
entries on the policy stack:

cmake_policy(PUSH)
cmake_policy(POP)

Each PUSH must have a matching POP to erase any changes. This is
useful to make temporary changes to policy settings.

Functions and macros record policy settings when they are created and
use the pre-record policies when they are invoked. If the function or
macro implementation sets policies, the changes automatically
propagate up through callers until they reach the closest nested
policy stack entry.

configure_file
Copy a file to another location and modify its contents.

configure_file(InputFile OutputFile
[COPYONLY] [ESCAPE_QUOTES] [@ONLY])

The Input and Output files have to have full paths. This command
replaces any variables in the input file referenced as ${VAR} or @VAR@
with their values as determined by CMake. If a variable is not
defined, it will be replaced with nothing. If COPYONLY is specified,
then no variable expansion will take place. If ESCAPE_QUOTES is
specified then any substituted quotes will be C-style escaped. The
file will be configured with the current values of CMake variables.
If @ONLY is specified, only variables of the form @VAR@ will be
replaces and ${VAR} will be ignored. This is useful for configuring
scripts that use ${VAR}. Any occurrences of #cmakedefine VAR will be
replaced with either #define VAR or /* #undef VAR */ depending on the
setting of VAR in CMake

create_test_sourcelist
Create a test driver and source list for building test programs.

create_test_sourcelist(sourceListName driverName
test1 test2 test3
EXTRA_INCLUDE include.h
FUNCTION function)

A test driver is a program that links together many small tests into a
single executable. This is useful when building static executables
with large libraries to shrink the total required size. The list of
source files needed to build the test driver will be in
sourceListName. DriverName is the name of the test driver program.
The rest of the arguments consist of a list of test source files, can
be semicolon separated. Each test source file should have a function
in it that is the same name as the file with no extension (foo.cxx
should have int foo(int, char*[]);) DriverName will be able to call
each of the tests by name on the command line. If EXTRA_INCLUDE is
specified, then the next argument is included into the generated file.
If FUNCTION is specified, then the next argument is taken as a
function name that is passed a pointer to ac and av. This can be used
to add extra command line processing to each test. The cmake variable
CMAKE_TESTDRIVER_BEFORE_TESTMAIN can be set to have code that will be
placed directly before calling the test main function.
CMAKE_TESTDRIVER_AFTER_TESTMAIN can be set to have code that will be
placed directly after the call to the test main function.

define_property
Define and document custom properties.

Define one property in a scope for use with the set_property and
get_property commands. This is primarily useful to associate
documentation with property names that may be retrieved with the
get_property command. The first argument determines the kind of scope
in which the property should be used. It must be one of the
following:

GLOBAL = associated with the global namespace
DIRECTORY = associated with one directory
TARGET = associated with one target
SOURCE = associated with one source file
TEST = associated with a test named with add_test command
VARIABLE = documents a CMake language variable
CACHED_VARIABLE = documents a CMake cache variable

Note that unlike set_property and get_property no actual scope needs
to be given; only the kind of scope is important.

The required PROPERTY option is immediately followed by the name of
the property being defined.

If the INHERITED option then the get_property command will chain up to
the next higher scope when the requested property is not set in the
scope given to the command. DIRECTORY scope chains to GLOBAL.
TARGET, SOURCE, and TEST chain to DIRECTORY.

The BRIEF_DOCS and FULL_DOCS options are followed by strings to be
associated with the property as its brief and full documentation.
Corresponding options to the get_property command will retrieve the
documentation.

else
Starts the else portion of an if block.

else(expression)

See the if command.

elseif
Starts the elseif portion of an if block.

elseif(expression)

See the if command.

enable_language
Enable a language (CXX/C/Fortran/etc)

enable_language(languageName [OPTIONAL] )

This command enables support for the named language in CMake. This is
the same as the project command but does not create any of the extra
variables that are created by the project command. Example languages
are CXX, C, Fortran.

If OPTIONAL is used, use the CMAKE_<languageName>_COMPILER_WORKS
variable to check whether the language has been enabled successfully.

enable_testing
Enable testing for current directory and below.

enable_testing()

Enables testing for this directory and below. See also the add_test
command. Note that ctest expects to find a test file in the build
directory root. Therefore, this command should be in the source
directory root.

endforeach
Ends a list of commands in a FOREACH block.

endforeach(expression)

See the FOREACH command.

endfunction
Ends a list of commands in a function block.

endfunction(expression)

See the function command.

endif
Ends a list of commands in an if block.

endif(expression)

See the if command.

endmacro
Ends a list of commands in a macro block.

endmacro(expression)

See the macro command.

endwhile
Ends a list of commands in a while block.

endwhile(expression)

See the while command.

execute_process
Execute one or more child processes.

execute_process(COMMAND <cmd1> [args1...]]
[COMMAND <cmd2> [args2...] [...]]
[WORKING_DIRECTORY <directory>]
[TIMEOUT <seconds>]
[RESULT_VARIABLE <variable>]
[OUTPUT_VARIABLE <variable>]
[ERROR_VARIABLE <variable>]
[INPUT_FILE <file>]
[OUTPUT_FILE <file>]
[ERROR_FILE <file>]
[OUTPUT_QUIET]
[ERROR_QUIET]
[OUTPUT_STRIP_TRAILING_WHITESPACE]
[ERROR_STRIP_TRAILING_WHITESPACE])

Runs the given sequence of one or more commands with the standard
output of each process piped to the standard input of the next. A
single standard error pipe is used for all processes. If
WORKING_DIRECTORY is given the named directory will be set as the
current working directory of the child processes. If TIMEOUT is given
the child processes will be terminated if they do not finish in the
specified number of seconds (fractions are allowed). If
RESULT_VARIABLE is given the variable will be set to contain the
result of running the processes. This will be an integer return code
from the last child or a string describing an error condition. If
OUTPUT_VARIABLE or ERROR_VARIABLE are given the variable named will be
set with the contents of the standard output and standard error pipes
respectively. If the same variable is named for both pipes their
output will be merged in the order produced. If INPUT_FILE,
OUTPUT_FILE, or ERROR_FILE is given the file named will be attached to
the standard input of the first process, standard output of the last
process, or standard error of all processes respectively. If
OUTPUT_QUIET or ERROR_QUIET is given then the standard output or
standard error results will be quietly ignored. If more than one
OUTPUT_* or ERROR_* option is given for the same pipe the precedence
is not specified. If no OUTPUT_* or ERROR_* options are given the
output will be shared with the corresponding pipes of the CMake
process itself.

The execute_process command is a newer more powerful version of
exec_program, but the old command has been kept for compatibility.

export
Export targets from the build tree for use by outside projects.

export(TARGETS [target1 [target2 [...]]] [NAMESPACE <namespace>]
[APPEND] FILE <filename>)

Create a file <filename> that may be included by outside projects to
import targets from the current project's build tree. This is useful
during cross-compiling to build utility executables that can run on
the host platform in one project and then import them into another
project being compiled for the target platform. If the NAMESPACE
option is given the <namespace> string will be prepended to all target
names written to the file. If the APPEND option is given the
generated code will be appended to the file instead of overwriting it.
If a library target is included in the export but a target to which it
links is not included the behavior is unspecified.

The file created by this command is specific to the build tree and
should never be installed. See the install(EXPORT) command to export
targets from an installation tree.

file
File manipulation command.

file(WRITE filename "message to write"... )
file(APPEND filename "message to write"... )
file(READ filename variable [LIMIT numBytes] [OFFSET offset] [HEX])
file(STRINGS filename variable [LIMIT_COUNT num]
[LIMIT_INPUT numBytes] [LIMIT_OUTPUT numBytes]
[LENGTH_MINIMUM numBytes] [LENGTH_MAXIMUM numBytes]
[NEWLINE_CONSUME] [REGEX regex]
[NO_HEX_CONVERSION])
file(GLOB variable [RELATIVE path] [globbing expressions]...)
file(GLOB_RECURSE variable [RELATIVE path]
[FOLLOW_SYMLINKS] [globbing expressions]...)
file(REMOVE [file1 ...])
file(REMOVE_RECURSE [file1 ...])
file(MAKE_DIRECTORY [directory1 directory2 ...])
file(RELATIVE_PATH variable directory file)
file(TO_CMAKE_PATH path result)
file(TO_NATIVE_PATH path result)
file(DOWNLOAD url file [TIMEOUT timeout] [STATUS status] [LOG log])

WRITE will write a message into a file called 'filename'. It
overwrites the file if it already exists, and creates the file if it
does not exist.

APPEND will write a message into a file same as WRITE, except it will
append it to the end of the file

READ will read the content of a file and store it into the variable.
It will start at the given offset and read up to numBytes. If the
argument HEX is given, the binary data will be converted to
hexadecimal representation and this will be stored in the variable.

STRINGS will parse a list of ASCII strings from a file and store it in
a variable. Binary data in the file are ignored. Carriage return
(CR) characters are ignored. It works also for Intel Hex and Motorola
S-record files, which are automatically converted to binary format
when reading them. Disable this using NO_HEX_CONVERSION.

LIMIT_COUNT sets the maximum number of strings to return. LIMIT_INPUT
sets the maximum number of bytes to read from the input file.
LIMIT_OUTPUT sets the maximum number of bytes to store in the output
variable. LENGTH_MINIMUM sets the minimum length of a string to
return. Shorter strings are ignored. LENGTH_MAXIMUM sets the maximum
length of a string to return. Longer strings are split into strings
no longer than the maximum length. NEWLINE_CONSUME allows newlines to
be included in strings instead of terminating them.

REGEX specifies a regular expression that a string must match to be
returned. Typical usage

file(STRINGS myfile.txt myfile)

stores a list in the variable "myfile" in which each item is a line
from the input file.

GLOB will generate a list of all files that match the globbing
expressions and store it into the variable. Globbing expressions are
similar to regular expressions, but much simpler. If RELATIVE flag is
specified for an expression, the results will be returned as a
relative path to the given path.

Examples of globbing expressions include:

*.cxx - match all files with extension cxx
*.vt? - match all files with extension vta,...,vtz
f[3-5].txt - match files f3.txt, f4.txt, f5.txt

GLOB_RECURSE will generate a list similar to the regular GLOB, except
it will traverse all the subdirectories of the matched directory and
match the files. Subdirectories that are symlinks are only traversed
if FOLLOW_SYMLINKS is given or cmake policy CMP0009 is not set to NEW.
See cmake --help-policy CMP0009 for more information.

Examples of recursive globbing include:

/dir/*.py - match all python files in /dir and subdirectories

MAKE_DIRECTORY will create the given directories, also if their parent
directories don't exist yet

REMOVE will remove the given files, also in subdirectories

REMOVE_RECURSE will remove the given files and directories, also
non-empty directories

RELATIVE_PATH will determine relative path from directory to the given
file.

TO_CMAKE_PATH will convert path into a cmake style path with unix /.
The input can be a single path or a system path like "$ENV{PATH}".
Note the double quotes around the ENV call TO_CMAKE_PATH only takes
one argument.

TO_NATIVE_PATH works just like TO_CMAKE_PATH, but will convert from a
cmake style path into the native path style \ for windows and / for
UNIX.

DOWNLOAD will download the given URL to the given file. If LOG var is
specified a log of the download will be put in var. If STATUS var is
specified the status of the operation will be put in var. The status
is returned in a list of length 2. The first element is the numeric
return value for the operation, and the second element is a string
value for the error. A 0 numeric error means no error in the
operation. If TIMEOUT time is specified, the operation will timeout
after time seconds, time can be specified as a float.

find_file
Find the full path to a file.

find_path(<VAR> name1 [path1 path2 ...])

This is the short-hand signature for the command that is sufficient in
many cases. It is the same as find_path(<VAR> name1 [PATHS path1
path2 ...])

find_path(
<VAR>
name | NAMES name1 [name2 ...]
[HINTS path1 [path2 ... ENV var]]
[PATHS path1 [path2 ... ENV var]]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[DOC "cache documentation string"]
[NO_DEFAULT_PATH]
[NO_CMAKE_ENVIRONMENT_PATH]
[NO_CMAKE_PATH]
[NO_SYSTEM_ENVIRONMENT_PATH]
[NO_CMAKE_SYSTEM_PATH]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)

This command is used to find a full path to named file. A cache entry
named by <VAR> is created to store the result of this command. If the
full path to a file is found the result is stored in the variable and
the search will not be repeated unless the variable is cleared. If
nothing is found, the result will be <VAR>-NOTFOUND, and the search
will be attempted again the next time find_path is invoked with the
same variable. The name of the full path to a file that is searched
for is specified by the names listed after the NAMES argument.
Additional search locations can be specified after the PATHS argument.
If ENV var is found in the HINTS or PATHS section the environment
variable var will be read and converted from a system environment
variable to a cmake style list of paths. For example ENV PATH would
be a way to list the system path variable. The argument after DOC
will be used for the documentation string in the cache. PATH_SUFFIXES
specifies additional subdirectories to check below each search path.

If NO_DEFAULT_PATH is specified, then no additional paths are added to
the search. If NO_DEFAULT_PATH is not specified, the search process
is as follows:

1. Search paths specified in cmake-specific cache variables. These
are intended to be used on the command line with a -DVAR=value. This
can be skipped if NO_CMAKE_PATH is passed.

<prefix>/include for each <prefix> in CMAKE_PREFIX_PATH
CMAKE_INCLUDE_PATH
CMAKE_FRAMEWORK_PATH

2. Search paths specified in cmake-specific environment variables.
These are intended to be set in the user's shell configuration. This
can be skipped if NO_CMAKE_ENVIRONMENT_PATH is passed.

<prefix>/include for each <prefix> in CMAKE_PREFIX_PATH
CMAKE_INCLUDE_PATH
CMAKE_FRAMEWORK_PATH

3. Search the paths specified by the HINTS option. These should be
paths computed by system introspection, such as a hint provided by the
location of another item already found. Hard-coded guesses should be
specified with the PATHS option.

4. Search the standard system environment variables. This can be
skipped if NO_SYSTEM_ENVIRONMENT_PATH is an argument.

PATH
INCLUDE

5. Search cmake variables defined in the Platform files for the
current system. This can be skipped if NO_CMAKE_SYSTEM_PATH is
passed.

<prefix>/include for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH
CMAKE_SYSTEM_INCLUDE_PATH
CMAKE_SYSTEM_FRAMEWORK_PATH

6. Search the paths specified by the PATHS option or in the
short-hand version of the command. These are typically hard-coded
guesses.

On Darwin or systems supporting OS X Frameworks, the cmake variable
CMAKE_FIND_FRAMEWORK can be set to empty or one of the following:

"FIRST" - Try to find frameworks before standard
libraries or headers. This is the default on Darwin.
"LAST" - Try to find frameworks after standard
libraries or headers.
"ONLY" - Only try to find frameworks.
"NEVER". - Never try to find frameworks.

On Darwin or systems supporting OS X Application Bundles, the cmake
variable CMAKE_FIND_APPBUNDLE can be set to empty or one of the
following:

"FIRST" - Try to find application bundles before standard
programs. This is the default on Darwin.
"LAST" - Try to find application bundles after standard
programs.
"ONLY" - Only try to find application bundles.
"NEVER". - Never try to find application bundles.

The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more
directories to be prepended to all other search directories. This
effectively "re-roots" the entire search under given locations. By
default it is empty. It is especially useful when cross-compiling to
point to the root directory of the target environment and CMake will
search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH and then the non-rooted directories will be
searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_INCLUDE. This behavior can be manually
overridden on a per-call basis. By using CMAKE_FIND_ROOT_PATH_BOTH
the search order will be as described above. If
NO_CMAKE_FIND_ROOT_PATH is used then CMAKE_FIND_ROOT_PATH will not be
used. If ONLY_CMAKE_FIND_ROOT_PATH is used then only the re-rooted
directories will be searched.

The default search order is designed to be most-specific to
least-specific for common use cases. Projects may override the order
by simply calling the command multiple times and using the NO_*
options:

find_path(<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_path(<VAR> NAMES name)

Once one of the calls succeeds the result variable will be set and
stored in the cache so that no call will search again.

find_library
Find a library.

find_library(<VAR> name1 [path1 path2 ...])

This is the short-hand signature for the command that is sufficient in
many cases. It is the same as find_library(<VAR> name1 [PATHS path1
path2 ...])

find_library(
<VAR>
name | NAMES name1 [name2 ...]
[HINTS path1 [path2 ... ENV var]]
[PATHS path1 [path2 ... ENV var]]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[DOC "cache documentation string"]
[NO_DEFAULT_PATH]
[NO_CMAKE_ENVIRONMENT_PATH]
[NO_CMAKE_PATH]
[NO_SYSTEM_ENVIRONMENT_PATH]
[NO_CMAKE_SYSTEM_PATH]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)

This command is used to find a library. A cache entry named by <VAR>
is created to store the result of this command. If the library is
found the result is stored in the variable and the search will not be
repeated unless the variable is cleared. If nothing is found, the
result will be <VAR>-NOTFOUND, and the search will be attempted again
the next time find_library is invoked with the same variable. The
name of the library that is searched for is specified by the names
listed after the NAMES argument. Additional search locations can be
specified after the PATHS argument. If ENV var is found in the HINTS
or PATHS section the environment variable var will be read and
converted from a system environment variable to a cmake style list of
paths. For example ENV PATH would be a way to list the system path
variable. The argument after DOC will be used for the documentation
string in the cache. PATH_SUFFIXES specifies additional
subdirectories to check below each search path.

If NO_DEFAULT_PATH is specified, then no additional paths are added to
the search. If NO_DEFAULT_PATH is not specified, the search process
is as follows:

1. Search paths specified in cmake-specific cache variables. These
are intended to be used on the command line with a -DVAR=value. This
can be skipped if NO_CMAKE_PATH is passed.

<prefix>/lib for each <prefix> in CMAKE_PREFIX_PATH
CMAKE_LIBRARY_PATH
CMAKE_FRAMEWORK_PATH

2. Search paths specified in cmake-specific environment variables.
These are intended to be set in the user's shell configuration. This
can be skipped if NO_CMAKE_ENVIRONMENT_PATH is passed.

<prefix>/lib for each <prefix> in CMAKE_PREFIX_PATH
CMAKE_LIBRARY_PATH
CMAKE_FRAMEWORK_PATH

3. Search the paths specified by the HINTS option. These should be
paths computed by system introspection, such as a hint provided by the
location of another item already found. Hard-coded guesses should be
specified with the PATHS option.

4. Search the standard system environment variables. This can be
skipped if NO_SYSTEM_ENVIRONMENT_PATH is an argument.

PATH
LIB

5. Search cmake variables defined in the Platform files for the
current system. This can be skipped if NO_CMAKE_SYSTEM_PATH is
passed.

<prefix>/lib for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH
CMAKE_SYSTEM_LIBRARY_PATH
CMAKE_SYSTEM_FRAMEWORK_PATH

6. Search the paths specified by the PATHS option or in the
short-hand version of the command. These are typically hard-coded
guesses.

On Darwin or systems supporting OS X Frameworks, the cmake variable
CMAKE_FIND_FRAMEWORK can be set to empty or one of the following:

"FIRST" - Try to find frameworks before standard
libraries or headers. This is the default on Darwin.
"LAST" - Try to find frameworks after standard
libraries or headers.
"ONLY" - Only try to find frameworks.
"NEVER". - Never try to find frameworks.

On Darwin or systems supporting OS X Application Bundles, the cmake
variable CMAKE_FIND_APPBUNDLE can be set to empty or one of the
following:

"FIRST" - Try to find application bundles before standard
programs. This is the default on Darwin.
"LAST" - Try to find application bundles after standard
programs.
"ONLY" - Only try to find application bundles.
"NEVER". - Never try to find application bundles.

The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more
directories to be prepended to all other search directories. This
effectively "re-roots" the entire search under given locations. By
default it is empty. It is especially useful when cross-compiling to
point to the root directory of the target environment and CMake will
search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH and then the non-rooted directories will be
searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_LIBRARY. This behavior can be manually
overridden on a per-call basis. By using CMAKE_FIND_ROOT_PATH_BOTH
the search order will be as described above. If
NO_CMAKE_FIND_ROOT_PATH is used then CMAKE_FIND_ROOT_PATH will not be
used. If ONLY_CMAKE_FIND_ROOT_PATH is used then only the re-rooted
directories will be searched.

The default search order is designed to be most-specific to
least-specific for common use cases. Projects may override the order
by simply calling the command multiple times and using the NO_*
options:

find_library(<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_library(<VAR> NAMES name)

Once one of the calls succeeds the result variable will be set and
stored in the cache so that no call will search again.

If the library found is a framework, then VAR will be set to the full
path to the framework <fullPath>/A.framework. When a full path to a
framework is used as a library, CMake will use a -framework A, and a
-F<fullPath> to link the framework to the target.

find_package
Load settings for an external project.

find_package(<package> [version] [EXACT] [QUIET]
[[REQUIRED|COMPONENTS] [components...]]
[NO_POLICY_SCOPE])

Finds and loads settings from an external project. <package>_FOUND
will be set to indicate whether the package was found. When the
package is found package-specific information is provided through
variables documented by the package itself. The QUIET option disables
messages if the package cannot be found. The REQUIRED option stops
processing with an error message if the package cannot be found. A
package-specific list of components may be listed after the REQUIRED
option or after the COMPONENTS option if no REQUIRED option is given.
The [version] argument requests a version with which the package found
should be compatible (format is major[.minor[.patch[.tweak]]]). The
EXACT option requests that the version be matched exactly. If no
[version] is given to a recursive invocation inside a find-module, the
[version] and EXACT arguments are forwarded automatically from the
outer call. Version support is currently provided only on a
package-by-package basis (details below).

User code should generally look for packages using the above simple
signature. The remainder of this command documentation specifies the
full command signature and details of the search process. Project
maintainers wishing to provide a package to be found by this command
are encouraged to read on.

The command has two modes by which it searches for packages: "Module"
mode and "Config" mode. Module mode is available when the command is
invoked with the above reduced signature. CMake searches for a file
called "Find<package>.cmake" in the CMAKE_MODULE_PATH followed by the
CMake installation. If the file is found, it is read and processed by
CMake. It is responsible for finding the package, checking the
version, and producing any needed messages. Many find-modules provide
limited or no support for versioning; check the module documentation.
If no module is found the command proceeds to Config mode.

The complete Config mode command signature is:

find_package(<package> [version] [EXACT] [QUIET]
[[REQUIRED|COMPONENTS] [components...]] [NO_MODULE]
[NO_POLICY_SCOPE]
[NAMES name1 [name2 ...]]
[CONFIGS config1 [config2 ...]]
[HINTS path1 [path2 ... ]]
[PATHS path1 [path2 ... ]]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[NO_DEFAULT_PATH]
[NO_CMAKE_ENVIRONMENT_PATH]
[NO_CMAKE_PATH]
[NO_SYSTEM_ENVIRONMENT_PATH]
[NO_CMAKE_BUILDS_PATH]
[NO_CMAKE_SYSTEM_PATH]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH])

The NO_MODULE option may be used to skip Module mode explicitly. It
is also implied by use of options not specified in the reduced
signature.

Config mode attempts to locate a configuration file provided by the
package to be found. A cache entry called <package>_DIR is created to
hold the directory containing the file. By default the command
searches for a package with the name <package>. If the NAMES option
is given the names following it are used instead of <package>. The
command searches for a file called "<name>Config.cmake" or
"<lower-case-name>-config.cmake" for each name specified. A
replacement set of possible configuration file names may be given
using the CONFIGS option. The search procedure is specified below.
Once found, the configuration file is read and processed by CMake.
Since the file is provided by the package it already knows the
location of package contents. The full path to the configuration file
is stored in the cmake variable <package>_CONFIG.

If the package configuration file cannot be found CMake will generate
an error describing the problem unless the QUIET argument is
specified. If REQUIRED is specified and the package is not found a
fatal error is generated and the configure step stops executing. If
<package>_DIR has been set to a directory not containing a
configuration file CMake will ignore it and search from scratch.

When the [version] argument is given Config mode will only find a
version of the package that claims compatibility with the requested
version (format is major[.minor[.patch[.tweak]]]). If the EXACT
option is given only a version of the package claiming an exact match
of the requested version may be found. CMake does not establish any
convention for the meaning of version numbers. Package version
numbers are checked by "version" files provided by the packages
themselves. For a candidate package confguration file
"<config-file>.cmake" the corresponding version file is located next
to it and named either "<config-file>-version.cmake" or
"<config-file>Version.cmake". If no such version file is available
then the configuration file is assumed to not be compatible with any
requested version. When a version file is found it is loaded to check
the requested version number. The version file is loaded in a nested
scope in which the following variables have been defined:

PACKAGE_FIND_NAME = the <package> name
PACKAGE_FIND_VERSION = full requested version string
PACKAGE_FIND_VERSION_MAJOR = major version if requested, else 0
PACKAGE_FIND_VERSION_MINOR = minor version if requested, else 0
PACKAGE_FIND_VERSION_PATCH = patch version if requested, else 0
PACKAGE_FIND_VERSION_TWEAK = tweak version if requested, else 0
PACKAGE_FIND_VERSION_COUNT = number of version components, 0 to 4

The version file checks whether it satisfies the requested version and
sets these variables:

PACKAGE_VERSION = full provided version string
PACKAGE_VERSION_EXACT = true if version is exact match
PACKAGE_VERSION_COMPATIBLE = true if version is compatible
PACKAGE_VERSION_UNSUITABLE = true if unsuitable as any version

These variables are checked by the find_package command to determine
whether the configuration file provides an acceptable version. They
are not available after the find_package call returns. If the version
is acceptable the following variables are set:

<package>_VERSION = full provided version string
<package>_VERSION_MAJOR = major version if provided, else 0
<package>_VERSION_MINOR = minor version if provided, else 0
<package>_VERSION_PATCH = patch version if provided, else 0
<package>_VERSION_TWEAK = tweak version if provided, else 0
<package>_VERSION_COUNT = number of version components, 0 to 4

and the corresponding package configuration file is loaded. When
multiple package configuration files are available whose version files
claim compatibility with the version requested it is unspecified which
one is chosen. No attempt is made to choose a highest or closest
version number.

Config mode provides an elaborate interface and search procedure.
Much of the interface is provided for completeness and for use
internally by find-modules loaded by Module mode. Most user code
should simply call

find_package(<package> [major[.minor]] [EXACT] [REQUIRED|QUIET])

in order to find a package. Package maintainers providing CMake
package configuration files are encouraged to name and install them
such that the procedure outlined below will find them without
requiring use of additional options.

CMake constructs a set of possible installation prefixes for the
package. Under each prefix several directories are searched for a
configuration file. The tables below show the directories searched.
Each entry is meant for installation trees following Windows (W), UNIX
(U), or Apple (A) conventions.

On systems supporting OS X Frameworks and Application Bundles the
following directories are searched for frameworks or bundles
containing a configuration file:

<prefix>/<name>.framework/Resources/ (A)
<prefix>/<name>.framework/Resources/CMake/ (A)
<prefix>/<name>.framework/Versions/*/Resources/ (A)
<prefix>/<name>.framework/Versions/*/Resources/CMake/ (A)
<prefix>/<name>.app/Contents/Resources/ (A)
<prefix>/<name>.app/Contents/Resources/CMake/ (A)

In all cases the <name> is treated as case-insensitive and corresponds
to any of the names specified (<package> or names given by NAMES). If
PATH_SUFFIXES is specified the suffixes are appended to each (W) or
(U) directory entry one-by-one.

This set of directories is intended to work in cooperation with
projects that provide configuration files in their installation trees.
Directories above marked with (W) are intended for installations on
Windows where the prefix may point at the top of an application's
installation directory. Those marked with (U) are intended for
installations on UNIX platforms where the prefix is shared by multiple
packages. This is merely a convention, so all (W) and (U) directories
are still searched on all platforms. Directories marked with (A) are
intended for installations on Apple platforms. The cmake variables
CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE determine the order of
preference as specified below.

The set of installation prefixes is constructed using the following
steps. If NO_DEFAULT_PATH is specified all NO_* options are enabled.

1. Search paths specified in cmake-specific cache variables. These
are intended to be used on the command line with a -DVAR=value. This
can be skipped if NO_CMAKE_PATH is passed.

CMAKE_PREFIX_PATH
CMAKE_FRAMEWORK_PATH
CMAKE_APPBUNDLE_PATH

2. Search paths specified in cmake-specific environment variables.
These are intended to be set in the user's shell configuration. This
can be skipped if NO_CMAKE_ENVIRONMENT_PATH is passed.

CMAKE_PREFIX_PATH
CMAKE_FRAMEWORK_PATH
CMAKE_APPBUNDLE_PATH

3. Search paths specified by the HINTS option. These should be paths
computed by system introspection, such as a hint provided by the
location of another item already found. Hard-coded guesses should be
specified with the PATHS option.

4. Search the standard system environment variables. This can be
skipped if NO_SYSTEM_ENVIRONMENT_PATH is passed. Path entries ending
in "/bin" or "/sbin" are automatically converted to their parent
directories.

PATH

5. Search project build trees recently configured in a CMake GUI.
This can be skipped if NO_CMAKE_BUILDS_PATH is passed. It is intended
for the case when a user is building multiple dependent projects one
after another.

6. Search cmake variables defined in the Platform files for the
current system. This can be skipped if NO_CMAKE_SYSTEM_PATH is
passed.

CMAKE_SYSTEM_PREFIX_PATH
CMAKE_SYSTEM_FRAMEWORK_PATH
CMAKE_SYSTEM_APPBUNDLE_PATH

7. Search paths specified by the PATHS option. These are typically
hard-coded guesses.

On Darwin or systems supporting OS X Frameworks, the cmake variable
CMAKE_FIND_FRAMEWORK can be set to empty or one of the following:

"FIRST" - Try to find frameworks before standard
libraries or headers. This is the default on Darwin.
"LAST" - Try to find frameworks after standard
libraries or headers.
"ONLY" - Only try to find frameworks.
"NEVER". - Never try to find frameworks.

On Darwin or systems supporting OS X Application Bundles, the cmake
variable CMAKE_FIND_APPBUNDLE can be set to empty or one of the
following:

"FIRST" - Try to find application bundles before standard
programs. This is the default on Darwin.
"LAST" - Try to find application bundles after standard
programs.
"ONLY" - Only try to find application bundles.
"NEVER". - Never try to find application bundles.

The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more
directories to be prepended to all other search directories. This
effectively "re-roots" the entire search under given locations. By
default it is empty. It is especially useful when cross-compiling to
point to the root directory of the target environment and CMake will
search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH and then the non-rooted directories will be
searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_PACKAGE. This behavior can be manually
overridden on a per-call basis. By using CMAKE_FIND_ROOT_PATH_BOTH
the search order will be as described above. If
NO_CMAKE_FIND_ROOT_PATH is used then CMAKE_FIND_ROOT_PATH will not be
used. If ONLY_CMAKE_FIND_ROOT_PATH is used then only the re-rooted
directories will be searched.

The default search order is designed to be most-specific to
least-specific for common use cases. Projects may override the order
by simply calling the command multiple times and using the NO_*
options:

find_package(<package> PATHS paths... NO_DEFAULT_PATH)
find_package(<package>)

Once one of the calls succeeds the result variable will be set and
stored in the cache so that no call will search again.

See the cmake_policy() command documentation for discussion of the
NO_POLICY_SCOPE option.

find_path
Find the directory containing a file.

find_path(<VAR> name1 [path1 path2 ...])

This is the short-hand signature for the command that is sufficient in
many cases. It is the same as find_path(<VAR> name1 [PATHS path1
path2 ...])

find_path(
<VAR>
name | NAMES name1 [name2 ...]
[HINTS path1 [path2 ... ENV var]]
[PATHS path1 [path2 ... ENV var]]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[DOC "cache documentation string"]
[NO_DEFAULT_PATH]
[NO_CMAKE_ENVIRONMENT_PATH]
[NO_CMAKE_PATH]
[NO_SYSTEM_ENVIRONMENT_PATH]
[NO_CMAKE_SYSTEM_PATH]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)

This command is used to find a directory containing the named file. A
cache entry named by <VAR> is created to store the result of this
command. If the file in a directory is found the result is stored in
the variable and the search will not be repeated unless the variable
is cleared. If nothing is found, the result will be <VAR>-NOTFOUND,
and the search will be attempted again the next time find_path is
invoked with the same variable. The name of the file in a directory
that is searched for is specified by the names listed after the NAMES
argument. Additional search locations can be specified after the
PATHS argument. If ENV var is found in the HINTS or PATHS section the
environment variable var will be read and converted from a system
environment variable to a cmake style list of paths. For example ENV
PATH would be a way to list the system path variable. The argument
after DOC will be used for the documentation string in the cache.
PATH_SUFFIXES specifies additional subdirectories to check below each
search path.