MAINT: Disable warnings for 3rdparty projects

In order to not be spammed with warnings from 3rdparty projects that we
make use of in Mumble, this commit modifies the respective cmake files
in a way that disables warnings for the respective projects.

1 files changed, 65 insertions, 0 deletions

diff --git a/cmake/project-utils.cmake b/cmake/project-utils.cmake
new file mode 100644
index 000000000..0991dfc08
--- /dev/null
+++ b/cmake/project-utils.cmake
@@ -0,0 +1,65 @@
+# Copyright 2020 The Mumble Developers. All rights reserved.
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file at the root of the
+# Mumble source tree or at <https://www.mumble.info/LICENSE>.
+
+# This function gets all included subdirectories in the given DIR recursively.
+# It'll write the found subdirs into SUBDIRS.
+# Note that the DIR itself will not be added to SUBDIRS
+# Note also that a subdirectory in this context is a dir that has been included with the
+# add_subdirectory command.
+function(get_subdirectories SUBDIRS DIR)
+	# Get the defined subdirs via the directory property
+	get_directory_property(NEW_SUBDIRS DIRECTORY "${DIR}" SUBDIRECTORIES)
+
+	# iterate all subdirs and call this function recursively to also get the
+	# subdirs of the subdirs (if any)
+	foreach(CURRENT_SUBDIR IN LISTS NEW_SUBDIRS)
+		get_subdirectories(REC_SUBDIRS "${CURRENT_SUBDIR}")
+		list(APPEND SUBDIRS ${REC_SUBDIRS})
+	endforeach()
+
+	list(APPEND SUBDIRS ${NEW_SUBDIRS})
+
+	# "Return" SUBDIRS
+	set(${SUBDIRS} PARENT_SCOPE)
+endfunction()
+
+# This function gets all defined targets in the given DIR or any of its
+# subdirectories as returned by get_subdirectories. The found targets are
+# written into DEFINED_TARGETS.
+function(get_targets DEFINED_TARGETS DIR)
+	# First get all defined subdirectories
+	get_subdirectories(SUBDIRS "${DIR}")
+
+	if(EXISTS "${DIR}/CMakeLists.txt")
+		# If the DIR itself contains a CMakeLists.txt file, add it to the
+		# list of directories to process as it may already define some targets
+		# itself.
+		list(APPEND SUBDIRS "${DIR}")
+	endif()
+
+	# Iterate over all directories and check each for the defined targets via the
+	# respective directory property.
+	foreach(CURRENT_SUBDIR IN LISTS SUBDIRS)
+		get_directory_property(NEW_TARGETS DIRECTORY "${CURRENT_SUBDIR}" BUILDSYSTEM_TARGETS)
+		list(APPEND DEFINED_TARGETS ${NEW_TARGETS})
+	endforeach()
+
+	# "Return" DEFINED_TARGETS
+	set(${DEFINED_TARGETS} PARENT_SCOPE)
+endfunction()
+
+# This function will disable all warnings for the targets defined in the given DIR
+# or any of its subdirectories as returned by get_subdirectories.
+function(disable_warnings_for_all_targets_in DIR)
+	# First get all targets
+	get_targets(DEFINED_TARGETS "${DIR}")
+
+	message(STATUS "Disabling warnings for targets: ${DEFINED_TARGETS}")
+
+	# Iterate over all targets and disable warnings for them
+	foreach(CURRENT_TARGET IN LISTS DEFINED_TARGETS)
+		target_disable_warnings("${CURRENT_TARGET}")
+	endforeach()
+endfunction()