build/rebuild-backend.mk
author Bobby Holley <bobbyholley@gmail.com>
Sat, 01 Dec 2018 03:05:56 +0000
changeset 449071 6fafd118a82a58aa39d9a4c26107a28f631e3a94
parent 343048 03804db09cf364ff228fc61409702d9a86d44ade
child 468486 5cc56532ff4a4b2b896f84e4b6e7889837acb42d
permissions -rw-r--r--
Bug 1510490 - Measure shader cache memory usage and remove total_gpu_bytes. r=mattwoodrow The latter causes confusion in the memory reports because it gets summed up and thus effectively doubles the reported texture memory usage. I've decided it's best to drop, and so might as well do that while we're already messing around with the memory reports and the associated boilerplate. Depends on D13439 Differential Revision: https://phabricator.services.mozilla.com/D13440

# 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))))