# $Id$
## @file
# lex unit.
#

#
# Copyright (c) 2008-2017 knut st. osmundsen <bird-kBuild-spam-xviiv@anduin.net>
#
# This file is part of kBuild.
#
# kBuild is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# kBuild is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with kBuild; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
#
#
# As a special exception you are granted permission to include this file, via
# the kmk include directive, as you wish without this in itself causing the
# resulting makefile, program or whatever to be covered by the GPL license.
# This exception does not however invalidate any other reasons why the makefile,
# program, whatever should not be covered the GPL.
#
#

ifdef UNIT_lex
 $(error kBuild: The lex unit was included twice!)
endif
UNIT_lex = lex

# Add our target properties.
PROPS_TOOLS += LEXTOOL
PROPS_SINGLE += LEXTOOL
PROPS_ACCUMULATE_R += LEXFLAGS

# Add ourselves to the default source handlers.
KBUILD_SRC_HANDLERS += \
  .l:def_src_handler_lex


## wrapper the compile command dependency check.
ifndef NO_COMPILE_CMDS_DEPS
 _DEP_LEX_CMDS = $$(comp-cmds-ex $$($(target)_$(subst :,_,$(source))_LEX_CMDS_PREV_),$$(commands $(out)),FORCE)
else
 _DEP_LEX_CMDS =
endif


##
# Generates the rules for running flex on a specific source file.
#
# @param    $(obj)    The object file.
# @param    lots more
define def_lex_rule
$(out) + $(output_extra) +| $(output_maybe) : \
		$(deps) \
		$(value _DEP_LEX_CMDS) \
		| \
		$(orderdeps)
	%$$(call MSG_COMPILE,$(target),$(source),$$@,$(type))
	$$(QUIET)$$(RM) -f -- $(dep) $(out) $(output_extra) $(output_maybe)

$(cmds)

ifndef NO_COMPILE_CMDS_DEPS
ifdef KBUILD_HAVE_OPTIMIZED_APPEND
	%$$(QUIET2)$$(APPEND) -ni '$(dep)' \
		'define $(target)_$(subst :,_,$(source))_LEX_CMDS_PREV_' \
		'--insert-command=$(out)' \
		'endef'
else
	%$$(QUIET2)$$(APPEND) '$(dep)'
	%$$(QUIET2)$$(APPEND) '$(dep)' 'define $(target)_$(subst :,_,$(source))_LEX_CMDS_PREV_'
	%$$(QUIET2)$$(APPEND) -c '$(dep)' '$(out)'
	%$$(QUIET2)$$(APPEND) '$(dep)' 'endef'
endif
endif

# update globals
_OUT_FILES += $(out) $(output_extra) $(output_maybe)
$(target)_GEN_SOURCES_ += $(out)
$(target)_2_INTERMEDIATES += $(intermediates)

endef # def_lex_rule

##
# Handler for .l files listed in the SOURCES properties.
#
# .l files are transformed into .c files that then gets compiled by
# the C compiler.
#
# @param    target      The target file.
# @param    source      The source file.
# @param    lots more
# @returns  quite a bit.
define def_src_handler_lex
# Figure out all the props.
local type := LEX
local tmp := $(kb-src-tool tool)
ifeq ($(tool),)
$(error kBuild: $(target) / $(sources) does not a (lex) tool defined!)
endif
ifndef TOOL_$(tool)_LEX_CMDS
$(error kBuild: TOOL_$(tool)_LEX_CMDS isn't defined! target=$(target) source=$(source) )
endif
local out := $(kb-obj-base outbase).c
local tmp := $(kb-src-prop LEXFLAGS,flags,left-to-right,)
local tmp := $(kb-src-prop DEPS,deps,left-to-right,$(defpath))
local tmp := $(kb-src-prop ORDERDEPS,orderdeps,left-to-right,$(defpath))
ifdef TOOL_$(tool)_LEX_OUT_FILE # .c/.cpp output depends on flags.
 local out := $(strip $(TOOL_$(tool)_LEX_OUT_FILE))
 ifeq ($(out),)
  local out := $(outbase).c
 endif
endif
local dirdep := $(call DIRDEP,$(dir $(out)))

# Adjust paths if we got a default path.
ifneq ($(defpath),)
 local source := $(abspathex $(source),$(defpath))
endif

# dependency file.
local dep := $(out)$(SUFF_DEP)
ifndef NO_COMPILE_CMDS_DEPS
 _DEPFILES_INCLUDED += $(dep)
 $(eval includedep $(dep))
endif

# call the tool
local cmds := $(TOOL_$(tool)_LEX_CMDS)
local output_extra := $(TOOL_$(tool)_LEX_OUTPUT)
local output_maybe := $(TOOL_$(tool)_LEX_OUTPUT_MAYBE)
local deps += $(TOOL_$(tool)_LEX_DEPEND) $(source)
local orderdeps += $(TOOL_$(tool)_LEX_DEPORD) $(dirdep)

# Whether it generates a header file depends on the tool / flags.
local intermediates := $(filter %.h %.hpp %.h++ %.H,$(output_extra))

# generate the rule.
$(eval $(def_lex_rule))

endef # def_src_handler_lex