build/rebuild-backend.mk
author Andrew Osmond <aosmond@mozilla.com>
Thu, 29 Nov 2018 14:38:28 -0500
changeset 449414 0861a85d13bb1664c019b76fc543d2679e39c99f
parent 343153 03804db09cf364ff228fc61409702d9a86d44ade
child 468412 5cc56532ff4a4b2b896f84e4b6e7889837acb42d
permissions -rw-r--r--
Bug 1510601 - Part 1. Move size increments into AnimationFrameBuffer::InsertInternal. r=tnikkel The size was originally incremented in AnimationFrameBuffer::Insert however if an animation was reset before we finished decoding, it would count some frames twice in the counter. Now we increment it inside InsertInternal, where AnimationFrameDiscardingQueue can make a more informed decision on whether the frame is a duplicate or not. Additionally we now fail explicitly when we insert more frames on subsequent decodes than the original decoders. This will help avoid getting out of sync with FrameAnimator. Differential Revision: https://phabricator.services.mozilla.com/D13464

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

BACKEND_GENERATION_SCRIPT ?= config.status

# A traditional rule would look like this:
#    backend.%:
#        @echo do stuff
#
# But with -j<n>, and multiple items in BUILD_BACKEND_FILES, the command would
# run multiple times in parallel.
#
# "Fortunately", make has some weird semantics for pattern rules: if there are
# multiple targets in a pattern rule and each of them is matched at most once,
# the command will only run once. So:
#     backend%RecursiveMakeBackend backend%FasterMakeBackend:
#         @echo do stuff
#     backend: backend.RecursiveMakeBackend backend.FasterMakeBackend
# would only execute the command once.
#
# Credit where due: http://stackoverflow.com/questions/2973445/gnu-makefile-rule-generating-a-few-targets-from-a-single-source-file/3077254#3077254
$(subst .,%,$(BUILD_BACKEND_FILES)):
	@echo 'Build configuration changed. Regenerating backend.'
	$(PYTHON) $(BACKEND_GENERATION_SCRIPT)

define build_backend_rule
$(1): $$(wildcard $$(shell cat $(1).in))

endef
$(foreach file,$(BUILD_BACKEND_FILES),$(eval $(call build_backend_rule,$(file))))