# 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/.

STANDALONE_MAKEFILE := 1

include $(topsrcdir)/config/rules.mk

# Building XPIDLs effectively consists of two steps:
#
#   1) Staging all .idl files to a common directory.
#   2) Doing everything with the .idl files.
#
# Each .idl file is processed into a .h file and typelib information.
# The .h file shares the same stem as the input file and is installed
# in the common headers include directory.
#
# XPIDL files are logically grouped together by modules. The typelib
# information for all XPIDLs in the same module is linked together into
# an .xpt file having the name of the module.
#
# As an optimization to reduce overall CPU usage, we process all .idl
# belonging to a module with a single command invocation. This prevents
# redundant parsing of .idl files and significantly reduces CPU cycles.

# For dependency files.
idl_deps_dir := .deps

dist_idl_dir := $(DIST)/idl
dist_include_dir := $(DIST)/include
dist_xpcrs_dir := $(DIST)/xpcrs
stub_file := xptdata.stub
process_py := $(topsrcdir)/python/mozbuild/mozbuild/action/xpidl-process.py
target_file := $(topobjdir)/xpcom/reflect/xptinfo/xptdata.cpp
xptdata_h := $(dist_include_dir)/xptdata.h
generated_files := $(target_file) $(xptdata_h)
code_gen_py := $(topsrcdir)/xpcom/reflect/xptinfo/xptcodegen.py
code_gen_deps := $(topsrcdir)/xpcom/ds/tools/perfecthash.py

# TODO we should use py_action, but that would require extra directories to be
# in the virtualenv.
%.xpt:
	$(REPORT_BUILD)
	$(PYTHON3) $(process_py) --depsdir $(idl_deps_dir) \
		--bindings-conf $(topsrcdir)/dom/bindings/Bindings.conf \
		$(foreach dir,$(all_idl_dirs),-I $(dir)) \
		$(dist_include_dir) $(dist_xpcrs_dir) $(@D) \
		$(basename $(notdir $@)) $($(basename $(notdir $@))_deps)
# When some IDL is added or removed, if the actual IDL file was already, or
# still is, in the tree, simple dependencies can't detect that the XPT needs
# to be rebuilt.
# Add the current value of $($(xpidl_module)_deps) in the depend file, such that
# we can later check if the value has changed since last build, which will
# indicate whether IDLs were added or removed.
# Note that removing previously built files is not covered.
	@echo $(basename $(notdir $@))_deps_built = $($(basename $(notdir $@))_deps) >> $(idl_deps_dir)/$(basename $(notdir $@)).pp

xpidl_modules := @xpidl_modules@
xpt_files := $(addsuffix .xpt,$(xpidl_modules))

@xpidl_rules@

depends_files := $(foreach root,$(xpidl_modules),$(idl_deps_dir)/$(root).pp)

ifdef COMPILE_ENVIRONMENT
xpidl:: $(generated_files)
endif

# See bug 1420119 for why we need the semicolon.
$(target_file) $(xptdata_h) : $(stub_file) ;

$(xpt_files): $(process_py) $(call mkdir_deps,$(idl_deps_dir) $(dist_include_dir) $(dist_xpcrs_dir))

$(stub_file) : $(xpt_files) $(code_gen_py) $(code_gen_deps)
	$(REPORT_BUILD)
	$(PYTHON3) $(code_gen_py) $(generated_files) $(xpt_files)
	@touch $@

-include $(depends_files)

define xpt_deps
$(1): $(call mkdir_deps,$(dir $(1)))
ifneq ($($(basename $(notdir $(1)))_deps),$($(basename $(notdir $(1)))_deps_built))
$(1): FORCE
endif
endef

$(foreach xpt,$(xpt_files),$(eval $(call xpt_deps,$(xpt))))

.PHONY: xpidl