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+Infrastructure for CMake-based packages
+---------------------------------------
+
+[[cmaketargets-tutorial]]
+
++CMAKETARGETS+ tutorial
+~~~~~~~~~~~~~~~~~~~~~~~
+
+First, let's see how to write a +.mk+ file for a CMake-based package,
+with an example :
+
+------------------------
+01: #############################################################
+02: #
+03: # libfoo
+04: #
+05: #############################################################
+06: LIBFOO_VERSION = 1.0
+07: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz
+08: LIBFOO_SITE = http://www.foosoftware.org/download
+09: LIBFOO_INSTALL_STAGING = YES
+10: LIBFOO_INSTALL_TARGET = YES
+11: LIBFOO_CONF_OPT = -DBUILD_DEMOS=ON
+12: LIBFOO_DEPENDENCIES = libglib2 host-pkg-config
+13:
+14: $(eval $(call CMAKETARGETS,package,libfoo))
+------------------------
+
+On line 6, we declare the version of the package.
+
+On line 7 and 8, we declare the name of the tarball and the location
+of the tarball on the Web. Buildroot will automatically download the
+tarball from this location.
+
+On line 9, we tell Buildroot to install the package to the staging
+directory. The staging directory, located in +output/staging/+
+is the directory where all the packages are installed, including their
+development files, etc. By default, packages are not installed to the
+staging directory, since usually, only libraries need to be installed in
+the staging directory: their development files are needed to compile
+other libraries or applications depending on them. Also by default, when
+staging installation is enabled, packages are installed in this location
+using the +make install+ command.
+
+On line 10, we tell Buildroot to also install the package to the
+target directory. This directory contains what will become the root
+filesystem running on the target. Usually, we try not to install header
+files and to install stripped versions of the binary. By default, target
+installation is enabled, so in fact, this line is not strictly
+necessary. Also by default, packages are installed in this location
+using the +make install+ command.
+
+On line 11, we tell Buildroot to pass custom options to CMake when it is
+configuring the package.
+
+On line 12, we declare our dependencies, so that they are built
+before the build process of our package starts.
+
+Finally, on line line 14, we invoke the +CMAKETARGETS+
+macro that generates all the Makefile rules that actually allows the
+package to be built.
+
+[[cmaketargets-reference]]
+
++CMAKETARGETS+ reference
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+The main macro of the CMake package infrastructure is
++CMAKETARGETS+. It has the same number of arguments and the same
+semantic as the +GENTARGETS+ macro, which is the main macro of the
+generic package infrastructure. For CMake packages, the ability to
+have target and host packages is also available.
+
+Just like the generic infrastructure, the CMake infrastructure works
+by defining a number of variables before calling the +CMAKETARGETS+
+macro.
+
+First, all the package metadata information variables that exist in
+the generic infrastructure also exist in the CMake infrastructure:
++LIBFOO_VERSION+, +LIBFOO_SOURCE+, +LIBFOO_PATCH+, +LIBFOO_SITE+,
++LIBFOO_SUBDIR+, +LIBFOO_DEPENDENCIES+, +LIBFOO_INSTALL_STAGING+,
++LIBFOO_INSTALL_TARGET+.
+
+A few additional variables, specific to the CMake infrastructure, can
+also be defined. Many of them are only useful in very specific cases,
+typical packages will therefore only use a few of them.
+
+* +LIBFOO_SUBDIR+ may contain the name of a subdirectory inside the
+  package that contains the main CMakeLists.txt file. This is useful,
+  if for example, the main CMakeLists.txt file is not at the root of
+  the tree extracted by the tarball. If +HOST_LIBFOO_SUBDIR+ is not
+  specified, it defaults to +LIBFOO_SUBDIR+.
+
+* +LIBFOO_CONF_ENV+, to specify additional environment variables to
+  pass to CMake. By default, empty.
+
+* +LIBFOO_CONF_OPT+, to specify additional configure options to pass
+  to CMake. By default, empty.
+
+* +LIBFOO_MAKE+, to specify an alternate +make+ command. This is
+  typically useful when parallel make is enabled in the configuration
+  (using +BR2_JLEVEL+) but that this feature should be disabled for
+  the given package, for one reason or another. By default, set to
+  +$(MAKE)+. If parallel building is not supported by the package,
+  then it should be set to +LIBFOO_MAKE=$(MAKE1)+.
+
+* +LIBFOO_MAKE_ENV+, to specify additional environment variables to
+  pass to make in the build step. These are passed before the +make+
+  command. By default, empty.
+
+* +LIBFOO_MAKE_OPT+, to specify additional variables to pass to make
+  in the build step. These are passed after the +make+ command. By
+  default, empty.
+
+* +LIBFOO_INSTALL_STAGING_OPT+ contains the make options used to
+  install the package to the staging directory. By default, the value
+  is +DESTDIR=$$(STAGING_DIR) install+, which is correct for most
+  CMake packages. It is still possible to override it.
+
+* +LIBFOO_INSTALL_TARGET_OPT+ contains the make options used to
+  install the package to the target directory. By default, the value
+  is +DESTDIR=$$(TARGET_DIR) install+. The default value is correct
+  for most CMake packages, but it is still possible to override it if
+  needed.
+
+* +LIBFOO_CLEAN_OPT+ contains the make options used to clean the
+  package. By default, the value is +clean+.
+
+With the CMake infrastructure, all the steps required to build and
+install the packages are already defined, and they generally work well
+for most CMake-based packages. However, when required, it is still
+possible to customize what is done in any particular step:
+
+* By adding a post-operation hook (after extract, patch, configure,
+  build or install). See the reference documentation of the generic
+  infrastructure for details.
+
+* By overriding one of the steps. For example, even if the CMake
+  infrastructure is used, if the package +.mk+ file defines its own
+  +LIBFOO_CONFIGURE_CMDS+ variable, it will be used instead of the
+  default CMake one. However, using this method should be restricted
+  to very specific cases. Do not use it in the general case.