CMake: Add FindZSTD.cmake and wire it up in configurejson2cmake.py

Zstd is used in the dev branch, so prepare for it.

Change-Id: I130d98e3888a1eb4c7444728fc5088c5dae9d911
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

cmake/FindZSTD.cmake

@@ -0,0 +1,49 @@
+#.rst:
+# FindZstd
+# ---------
+#
+# Try to locate the Zstd library.
+# If found, this will define the following variables:
+#
+# ``ZSTD_FOUND``
+#     True if the zstd library is available
+# ``ZSTD_INCLUDE_DIRS``
+#     The zstd include directories
+# ``ZSTD_LIBRARIES``
+#     The zstd libraries for linking
+#
+# If ``ZSTD_FOUND`` is TRUE, it will also define the following
+# imported target:
+#
+# ``ZSTD::ZSTD``
+#     The zstd library
+
+find_package(PkgConfig)
+pkg_check_modules(PC_ZSTD QUIET libzstd)
+
+find_path(ZSTD_INCLUDE_DIRS
+          NAMES zstd.h
+          HINTS ${PC_ZSTD_INCLUDEDIR}
+          PATH_SUFFIXES zstd)
+
+find_library(ZSTD_LIBRARIES
+             NAMES zstd
+             HINTS ${PC_ZSTD_LIBDIR}
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(ZSTD DEFAULT_MSG ZSTD_LIBRARIES ZSTD_INCLUDE_DIRS)
+
+if(ZSTD_FOUND AND NOT TARGET ZSTD::ZSTD)
+  add_library(ZSTD::ZSTD UNKNOWN IMPORTED)
+  set_target_properties(ZSTD::ZSTD PROPERTIES
+                        IMPORTED_LOCATION "${ZSTD_LIBRARIES}"
+                        INTERFACE_INCLUDE_DIRECTORIES "${ZSTD_INCLUDE_DIRS}")
+endif()
+
+mark_as_advanced(ZSTD_INCLUDE_DIRS ZSTD_LIBRARIES)
+
+set_package_properties(ZSTD PROPERTIES
+  URL "https://github.com/facebook/zstd"
+  DESCRIPTION "ZSTD compression library")
+

util/cmake/configurejson2cmake.py

@@ -92,6 +92,7 @@ def map_library(lib: str) -> Union[str, LibraryMapping, List[str]]:
        'xlib': 'X11',
        'xrender': LibraryMapping(package="XCB", resultVariable="XCB_RENDER"),
        'zlib': 'ZLIB',
+       'zstd': 'ZSTD',
     }  # type: Dict[str, Union[str, List[str], LibraryMapping]]
     if lib not in libmap:
         raise Exception('    XXXX Unknown library "{}".'.format(lib))