#
-# (C) Copyright 2006
+# (C) Copyright 2006-2013
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
-# See file CREDITS for list of people who contributed to this
-# project.
+# SPDX-License-Identifier: GPL-2.0+
#
-# This program 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.
-#
-# This program 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 this program; if not, write to the Free Software
-# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-# MA 02111-1307 USA
-#
-
#########################################################################
_depend: $(obj).depend
-$(obj).depend: $(src)Makefile $(TOPDIR)/config.mk $(SRCS) $(HOSTSRCS)
- @rm -f $@
- @touch $@
- @for f in $(SRCS); do \
- g=`basename $$f | sed -e 's/\(.*\)\.\w/\1.o/'`; \
- $(CC) -M $(CPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; \
- done
- @for f in $(HOSTSRCS); do \
- g=`basename $$f | sed -e 's/\(.*\)\.\w/\1.o/'`; \
- $(HOSTCC) -M $(HOSTCPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; \
- done
+# Split the source files into two camps: those in the current directory, and
+# those somewhere else. For the first camp we want to support CPPFLAGS_<fname>
+# and for the second we don't / can't.
+PWD_SRCS := $(filter $(notdir $(SRCS)),$(SRCS))
+OTHER_SRCS := $(filter-out $(notdir $(SRCS)),$(SRCS))
+
+# This is a list of dependency files to generate
+DEPS := $(basename $(patsubst %,$(obj).depend.%,$(PWD_SRCS)))
+
+# Join all the dependencies into a single file, in three parts
+# 1 .Concatenate all the generated depend files together
+# 2. Add in the deps from OTHER_SRCS which we couldn't process
+# 3. Add in the HOSTSRCS
+$(obj).depend: $(src)Makefile $(TOPDIR)/config.mk $(DEPS) $(OTHER_SRCS) \
+ $(HOSTSRCS)
+ cat /dev/null $(DEPS) >$@
+ @for f in $(OTHER_SRCS); do \
+ g=`basename $$f | sed -e 's/\(.*\)\.[[:alnum:]_]/\1.o/'`; \
+ $(CC) -M $(CPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; \
+ done
+ @for f in $(HOSTSRCS); do \
+ g=`basename $$f | sed -e 's/\(.*\)\.[[:alnum:]_]/\1.o/'`; \
+ $(HOSTCC) -M $(HOSTCPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; \
+ done
+
+MAKE_DEPEND = $(CC) -M $(CPPFLAGS) $(EXTRA_CPPFLAGS_DEP) \
+ -MQ $(addsuffix .o,$(obj)$(basename $<)) $< >$@
+
+
+$(obj).depend.%: %.c
+ $(MAKE_DEPEND)
+
+$(obj).depend.%: %.S
+ $(MAKE_DEPEND)
$(HOSTOBJS): $(obj)%.o: %.c
$(HOSTCC) $(HOSTCFLAGS) $(HOSTCFLAGS_$(@F)) $(HOSTCFLAGS_$(BCURDIR)) -o $@ $< -c