ifneq ($(MKENV_INCLUDED),1)
# We assume that mkenv is in the same directory as this file.
THIS_MAKEFILE = $(lastword $(MAKEFILE_LIST))
include $(dir $(THIS_MAKEFILE))mkenv.mk
endif

# This file expects that OBJ contains a list of all of the object files.
# The directory portion of each object file is used to locate the source
# and should not contain any ..'s but rather be relative to the top of the 
# tree.
#
# So for example, py/map.c would have an object file name py/map.o
# The object files will go into the build directory and mantain the same
# directory structure as the source tree. So the final dependency will look
# like this:
#
# build/py/map.o: py/map.c
#
# We set vpath to point to the top of the tree so that the source files
# can be located. By following this scheme, it allows a single build rule
# to be used to compile all .c files.

vpath %.S . $(TOP)
$(BUILD)/%.o: %.S
	$(ECHO) "CC $<"
	$(Q)$(CC) $(CFLAGS) -c -o $@ $<

vpath %.s . $(TOP)
$(BUILD)/%.o: %.s
	$(ECHO) "AS $<"
	$(Q)$(AS) -o $@ $<

define compile_c
$(ECHO) "CC $<"
$(Q)$(CC) $(CFLAGS) -c -MD -o $@ $<
@# The following fixes the dependency file.
@# See http://make.paulandlesley.org/autodep.html for details.
@cp $(@:.o=.d) $(@:.o=.P); \
  sed -e 's/#.*//' -e 's/^[^:]*: *//' -e 's/ *\\$$//' \
      -e '/^$$/ d' -e 's/$$/ :/' < $(@:.o=.d) >> $(@:.o=.P); \
  rm -f $(@:.o=.d)
endef

vpath %.c . $(TOP)
$(BUILD)/%.o: %.c
	$(call compile_c)

# The following rule uses | to create an order only prereuisite. Order only
# prerequisites only get built if they don't exist. They don't cause timestamp
# checkng to be performed.
#
# $(sort $(var)) removes duplicates
#
# The net effect of this, is it causes the objects to depend on the
# object directories (but only for existance), and the object directories
# will be created if they don't exist.
OBJ_DIRS = $(sort $(dir $(OBJ)))
$(OBJ): | $(OBJ_DIRS)
$(OBJ_DIRS):
	mkdir -p $@

ifneq ($(PROG),)
# Build a standalone executable (unix and unix-cpy do this)

all: $(PROG)

$(PROG): $(OBJ)
	$(ECHO) "LINK $<"
	$(Q)$(CC) -o $@ $(OBJ) $(LIB) $(LDFLAGS)
ifndef DEBUG
	$(Q)strip $(PROG)
endif
	$(Q)size $(PROG)

clean: clean-prog
clean-prog:
	$(RM) -f $(PROG)

.PHONY: clean-prog
endif

clean:
	$(RM) -rf $(BUILD)
.PHONY: clean

print-cfg:
	$(ECHO) "PY_SRC = $(PY_SRC)"
	$(ECHO) "BUILD  = $(BUILD)"
	$(ECHO) "OBJ    = $(OBJ)"
.PHONY: print-cfg

-include $(OBJ:.o=.P)