#############################################################
# Required variables for each makefile
# Discard this section from all parent makefiles
# Expected variables (with automatic defaults):
#   CSRCS (all "C" files in the dir)
#   SUBDIRS (all subdirs with a Makefile)
#   GEN_LIBS - list of libs to be generated ()
#   GEN_IMAGES - list of images to be generated ()
#   COMPONENTS_xxx - a list of libs/objs in the form
#     subdir/lib to be extracted and rolled up into
#     a generated lib/image xxx.a ()
#   DEPENDS_xxx - a list of explicit dependencies
#   TARGET - platform name
#
ifndef PDIR

SUBDIRS = host target

endif


#############################################################
# Configuration i.e. compile options etc.
# Target specific stuff (defines etc.) goes in here!
# Generally values applying to a tree are captured in the
#   makefile at its root level - these are then overridden
#   for a subtree within the makefile rooted therein
#

#############################################################
# Computed variables
# Should be done in top-level makefile only
#

CSRCS ?= $(wildcard *.c)
ASRCs ?= $(wildcard *.s)
ASRCS ?= $(wildcard *.S)
SUBDIRS ?= $(patsubst %/,%,$(dir $(wildcard */Makefile)))

ODIR := .output
OBJODIR := $(ODIR)/$(TARGET)/obj

OBJS := $(CSRCS:%.c=$(OBJODIR)/%.o) \
	$(ASRCs:%.s=$(OBJODIR)/%.o) \
	$(ASRCS:%.S=$(OBJODIR)/%.o)

DEPS := $(CSRCS:%.c=$(OBJODIR)/%.d) \
	$(ASRCs:%.s=$(OBJODIR)/%.d) \
	$(ASRCS:%.S=$(OBJODIR)/%.d)

LIBODIR := $(ODIR)/$(TARGET)/lib
OLIBS := $(GEN_LIBS:%=$(LIBODIR)/%)

IMAGEODIR := $(ODIR)/$(TARGET)/image
OIMAGES := $(GEN_IMAGES:%=$(IMAGEODIR)/%)

BINODIR := $(ODIR)/$(TARGET)/bin
OBINS := $(GEN_BINS:%=$(BINODIR)/%) \
         $(FIRMWARE_BINS:%=$(BINODIR)/%) \

CPPFLAGS = $(COPTS) $(DEFINES) $(INCLUDES)
CFLAGS = $(CPPFLAGS)

DPPFLAGS = $(DOPTS) $(DDEFINES) $(INCLUDES)
DFLAGS = $(DPPFLAGS)

EXTRACT_DIR = $(ODIR)/$(TARGET)/.extract
UP_EXTRACT_DIR = ../../..

#############################################################
# Functions
#

define ShortcutRule
$(1): .subdirs $(2)/$(1)
endef

define MakeLibrary
DEP_LIBS_$(1) = $$(foreach lib,$$(filter %.a,$$(COMPONENTS_$(1))),$$(dir $$(lib))$$(LIBODIR)/$$(notdir $$(lib)))
DEP_OBJS_$(1) = $$(foreach obj,$$(filter %.o,$$(COMPONENTS_$(1))),$$(dir $$(obj))$$(OBJODIR)/$$(notdir $$(obj)))
$$(LIBODIR)/$(1).a: $$(OBJS) $$(DEP_OBJS_$(1)) $$(DEP_LIBS_$(1))
	@mkdir -p $$(LIBODIR)
	$$(if $$(filter %.a,$$?),mkdir -p $$(EXTRACT_DIR)_$(1))
	$$(if $$(filter %.a,$$?),cd $$(EXTRACT_DIR)_$(1); $$(foreach lib,$$(filter %.a,$$?),$$(AR) xo $$(UP_EXTRACT_DIR)/$$(lib);))
	$$(AR) ru $$@ $$(filter %.o,$$?) $$(if $$(filter %.a,$$?),$$(EXTRACT_DIR)_$(1)/*.o)
	$$(if $$(filter %.a,$$?),$$(RM) -r $$(EXTRACT_DIR)_$(1))
endef

define MakeImage
DEP_LIBS_$(1) = $$(foreach lib,$$(filter %.a,$$(COMPONENTS_$(1))),$$(dir $$(lib))$$(LIBODIR)/$$(notdir $$(lib)))
DEP_OBJS_$(1) = $$(foreach obj,$$(filter %.o,$$(COMPONENTS_$(1))),$$(dir $$(obj))$$(OBJODIR)/$$(notdir $$(obj)))
$$(IMAGEODIR)/$(1).out: $$(OBJS) $$(DEP_OBJS_$(1)) $$(DEP_LIBS_$(1)) $$(DEPENDS_$(1))
	@mkdir -p $$(IMAGEODIR)
	$$(CC) $$(LDFLAGS) $$(if $$(LINKFLAGS_$(1)),$$(LINKFLAGS_$(1)),$$(LINKFLAGS_DEFAULT) $$(OBJS) $$(DEP_OBJS_$(1)) $$(DEP_LIBS_$(1))) -o $$@ 
endef

#############################################################
# Rules base
# Should be done in top-level makefile only
#

all:	.subdirs $(OBJS) $(OLIBS) $(OIMAGES) $(OBINS)

clean:
	$(foreach d, $(SUBDIRS), $(MAKE) -C $(d) clean;)
	$(RM) -r $(ODIR)/$(TARGET)

clobber:
	$(foreach d, $(SUBDIRS), $(MAKE) -C $(d) clobber;)
	$(RM) -r $(ODIR)

.subdirs:
	@set -e; $(foreach d, $(SUBDIRS), $(MAKE) -C $(d);)

ifdef DEPS
sinclude $(DEPS)
endif

$(OBJODIR)/%.o: %.c
	@mkdir -p $(OBJODIR);
	$(CC) $(if $(findstring $<,$(DSRCS)),$(DFLAGS),$(CFLAGS)) $(COPTS_$(*F)) -o $@ -c $<

$(OBJODIR)/%.d: %.c
	@mkdir -p $(OBJODIR); \
	set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\.o\)[ :]*,$(OBJODIR)/\1 $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

$(OBJODIR)/%.o: %.s
	@mkdir -p $(OBJODIR);
	$(CC) $(CFLAGS) -o $@ -c $<

$(OBJODIR)/%.d: %.s
	@mkdir -p $(OBJODIR); \
	set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\.o\)[ :]*,$(OBJODIR)/\1 $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

$(OBJODIR)/%.o: %.S
	@mkdir -p $(OBJODIR);
	$(CC) $(CFLAGS) -D__ASSEMBLER__ -o $@ -c $<

$(OBJODIR)/%.d: %.S
	@mkdir -p $(OBJODIR); \
	set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\.o\)[ :]*,$(OBJODIR)/\1 $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

$(BINODIR)/%.bin: $(IMAGEODIR)/%.out
	@mkdir -p $(BINODIR);
	$(OBJCOPY) -O binary $< $@ 

$(foreach lib,$(GEN_LIBS),$(eval $(call ShortcutRule,$(lib),$(LIBODIR))))

$(foreach image,$(GEN_IMAGES),$(eval $(call ShortcutRule,$(image),$(IMAGEODIR))))

$(foreach lib,$(GEN_LIBS),$(eval $(call MakeLibrary,$(basename $(lib)))))

$(foreach image,$(GEN_IMAGES),$(eval $(call MakeImage,$(basename $(image)))))

$(foreach bin,$(GEN_BINS),$(eval $(call MakeBin,$(basename $(bin)))))

#############################################################
# Recursion Magic - Don't touch this!!
#
# Each subtree potentially has an include directory
#   corresponding to the common APIs applicable to modules
#   rooted at that subtree. Accordingly, the INCLUDE PATH
#   of a module can only contain the include directories up
#   its parent path, and not its siblings
#
# Required for each makefile to inherit from the parent
#

INCLUDES := $(INCLUDES) -I $(PDIR)include -I $(PDIR)include/$(TARGET)
PDIR := ../$(PDIR)
sinclude $(PDIR)Makefile