# $Id$
## @file
# kBuild Unit - Target Level Precompiled Headers for GNU GCC.
#

#
# Copyright (c) 2016-2019 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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.
#
#


UNIT_gccprecomp = Target level precompiled Headers for Visual C++

#
# Early target processing pass #1.
#
# This sets $(target)_1_GCC_PCH_DIR as the include directory for the precompiled
# header, adding it to BLDDIRS to get a mkdir rule for it, and then calculates the
# .gch name and stores that in $(target)_1_GCC_PCH_FILE for compile rule dependencies.
#
define def_unit_gccprecomp_target_pre
 $(target)_BLDDIRS        += $($(target)_0_OUTDIR)/pch/
 $(target)_1_GCC_PCH_DIR  := $($(target)_0_OUTDIR)/pch/
 $(target)_1_GCC_PCH_FILE := $($(target)_0_OUTDIR)/pch/$(notdir $($(target)_PCH_HDR)).gch
endef

#
# Early target processing pass #2.
#
# This sets up a rule for creating the .gch file after qt5 and similar units
# are done modifying INCS, DEFS and company.  The 'tool' variable is defined by
# footer-pass2-compiling-targets.kmk and is really the LD tool, but that'll
# have to do for now.  The '-PCH' variant of the GCC/LLVM tool, is defined together
# with $(tool) and allow us to bypass the options and dependencies triggered
# by _1_VCC_PCH_FILE, _1_VCC_COMMON_OBJ_PDB and _PCH_HDR, and also make sure we
# don't get circular dependencies by way of kDepObj and the debug info.
#
define def_unit_gccprecomp_target_pre_2
 local source := $($(target)_PCH_HDR)
 local suff   := $(suffix $(source))
 local type   := PCH
 $(kb-src-one 4)
endef