Fix QRC dependency issues (#6349)

cmake/modules/GenQrc.cmake

@@ -1,48 +1,80 @@
 # GenQrc.cmake - Copyright (c) 2015 Lukas W <lukaswhl/at/gmail.com>
 
-# Generates a simple qrc file containing the given resource files ${ARGN}:
-#     GEN_QRC(resources.qrc artwork.png icon.png PREFIX /icons)
-# Files may also be added using a pattern with the GLOB keyword, e.g.:
-#     GEN_QRC(resources.qrc GLOB *.png)
-FUNCTION(GEN_QRC OUT_FILE)
-	CMAKE_PARSE_ARGUMENTS(RC "" "PREFIX;GLOB" "" ${ARGN})
-
-	IF(DEFINED RC_GLOB)
-		FILE(GLOB GLOB_FILES ${RC_GLOB})
-	ENDIF()
-
-	# Set the standard prefix to "/" if none is given
-	IF(NOT DEFINED RC_PREFIX)
-		SET(RC_PREFIX "/")
-	ENDIF()
-
-	# We need to convert our list to a string in order to pass it to the script
-	# on the command line.
-	STRING(REPLACE ";" "\;" FILES "${RC_UNPARSED_ARGUMENTS};${GLOB_FILES}")
-
-	SET(GENQRC_SCRIPT "${CMAKE_SOURCE_DIR}/cmake/scripts/GenQrc.cmake")
-	ADD_CUSTOM_COMMAND(
-		OUTPUT ${OUT_FILE}
-		COMMAND ${CMAKE_COMMAND} -D OUT_FILE=${OUT_FILE} -D RC_PREFIX=${RC_PREFIX} -D FILES:list=${FILES} -D DIR=${CMAKE_CURRENT_SOURCE_DIR} -P "${GENQRC_SCRIPT}"
-		DEPENDS ${GENQRC_SCRIPT}
-		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-		VERBATIM
-	)
-ENDFUNCTION()
-
-# Generates a qrc file named ${QRC_OUT} from ${ARGN}, rccs it and returns Qt's
-# output file.
+# Generates a simple qrc file named ${QRC_NAME} containing the given resource
+# files ${ARGN}, rccs it, and returns Qt's output file.
 # Must only be run once per CMakeLists.txt.
 # Usage example:
-#     ADD_GEN_QRC(RCC_OUTPUT resources.qrc icon.png manual.pdf)
-#     ADD_EXECUTABLE(myexe main.cpp ${RCC_OUTPUT})
-MACRO(ADD_GEN_QRC RCCOUT QRC_OUT)
-	IF(NOT IS_ABSOLUTE ${QRC_OUT})
-		SET(QRC_FILE "${CMAKE_CURRENT_BINARY_DIR}/${QRC_OUT}")
-	ELSE()
-		SET(QRC_FILE ${QRC_OUT})
-	ENDIF()
+#     add_gen_qrc(RCC_OUTPUT resources.qrc artwork.png icon.png PREFIX /icons)
+#     add_executable(myexe main.cpp ${RCC_OUTPUT})
+# Files may also be added using a pattern with the GLOB keyword, e.g.:
+#     add_gen_qrc(RCC_OUTPUT resources.qrc GLOB *.png)
+function(add_gen_qrc RCC_OUT QRC_NAME)
+	cmake_parse_arguments(RC "" "PREFIX;GLOB" "" ${ARGN})
 
-	GEN_QRC(${QRC_FILE} "${ARGN}")
-	QT5_ADD_RESOURCES(${RCCOUT} ${QRC_FILE})
-ENDMACRO()
+	# Get the absolute paths for the generated files
+	if(IS_ABSOLUTE "${QRC_NAME}")
+		set(QRC_FILE "${QRC_NAME}")
+	else()
+		set(QRC_FILE "${CMAKE_CURRENT_BINARY_DIR}/${QRC_NAME}")
+	endif()
+	get_filename_component(RESOURCE_NAME "${QRC_FILE}" NAME_WE)
+	get_filename_component(OUTPUT_DIR "${QRC_FILE}" DIRECTORY)
+	set(CPP_FILE "${OUTPUT_DIR}/qrc_${RESOURCE_NAME}.cpp")
+
+	# Set the standard prefix to "/" if none is given
+	if(NOT DEFINED RC_PREFIX)
+		set(RC_PREFIX "/")
+	endif()
+
+	# Determine input files
+	set(FILES ${RC_UNPARSED_ARGUMENTS})
+	if(DEFINED RC_GLOB)
+		file(GLOB GLOB_FILES "${RC_GLOB}")
+		list(APPEND FILES ${GLOB_FILES})
+	endif()
+
+	# Add the command to generate the QRC file
+	set(GENQRC_SCRIPT "${CMAKE_SOURCE_DIR}/cmake/scripts/GenQrc.cmake")
+	add_custom_command(
+		OUTPUT "${QRC_FILE}"
+		COMMAND "${CMAKE_COMMAND}"
+			-D "OUT_FILE=${QRC_FILE}"
+			-D "RC_PREFIX=${RC_PREFIX}"
+			-D "FILES:list=${FILES}"
+			-D "DIR=${CMAKE_CURRENT_SOURCE_DIR}"
+			-P "${GENQRC_SCRIPT}"
+		DEPENDS "${GENQRC_SCRIPT}"
+		WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+		VERBATIM
+	)
+
+	# Add the command to compile the QRC file
+	# Note: we can't use `qt5_add_resources` or `AUTORCC` here; we have to add
+	# the command ourselves instead. This is in order to handle dependencies
+	# correctly: the QRC file is generated at build time, so the dependencies
+	# of the compiled file can't be automatically determined at configure time.
+	# Additionally, `qt5_add_resources` adds unnecessary dependencies for
+	# generated QRC files, which can cause dependency cycles with some
+	# generators. See issue #6177.
+	add_custom_command(
+		OUTPUT "${CPP_FILE}"
+		COMMAND Qt5::rcc
+			--name "${RESOURCE_NAME}"
+			--output "${CPP_FILE}"
+			"${QRC_FILE}"
+		DEPENDS "${QRC_FILE}" ${FILES}
+		VERBATIM
+	)
+
+	# Flag the generated files to be ignored by automatic tool processing
+	set_source_files_properties("${QRC_FILE}" PROPERTIES
+		SKIP_AUTORCC ON # We added the rcc command for this manually
+	)
+	set_source_files_properties("${CPP_FILE}" PROPERTIES
+		SKIP_AUTOMOC ON # The rcc output file has no need for moc or uic
+		SKIP_AUTOUIC ON
+	)
+
+	# Return the rcc output file
+	set("${RCC_OUT}" "${CPP_FILE}" PARENT_SCOPE)
+endfunction()