Autodependencies

PRODUCT := chill
SRCDIR := src
DEPDIR := dep
BINDIR := bin
OBJDIR := obj

CC := gcc
CCEXT := c
CCFLAGS := -Wall -std=c11
# CCFLAGS := -Wall -Ofast -std=c11

FILES := $(shell find $(SRCDIR) -name *.$(CCEXT))

$(PRODUCT): $(patsubst %,$(OBJDIR)/%.o,$(subst /,__,$(patsubst $(SRCDIR)/%,%,$(FILES))))
    @$(CC) -o $(BINDIR)/$(PRODUCT) $(patsubst %,$(OBJDIR)/%.o,$(subst /,__,$(patsubst $(SRCDIR)/%,%,$(FILES)))) $(CCFLAGS)

-include $(patsubst %,$(DEPDIR)/%.dep,$(subst /,__,$(patsubst $(SRCDIR)/%,%,$(FILES))))

$(OBJDIR)/%.$(CCEXT).o:
    @$(eval CPATH := $(patsubst %,$(SRCDIR)/%,$(subst __,/,$*.$(CCEXT))))
    @$(eval DPATH := $(patsubst %,$(DEPDIR)/%,$*.$(CCEXT)).dep)
    @$(CC) $(CCFLAGS) -c $(CPATH) -o $(OBJDIR)/$*.$(CCEXT).o
    @$(CC) $(CCFLAGS) -MM $(CPATH) > $(DPATH)
    @mv -f $(DPATH) $(DPATH).tmp
    @sed -e 's|.*:|$(OBJDIR)/$*.$(CCEXT).o:|' < $(DPATH).tmp > $(DPATH)
    @sed -e 's/.*://' -e 's/\\$$//' < $(DPATH).tmp | fmt -1 | \
      sed -e 's/^ *//' -e 's/$$/:/' >> $(DPATH)
    @rm -f $(DPATH).tmp

clean:
    @rm -f $(BINDIR)/$(PRODUCT) $(OBJDIR)/*.o $(DEPDIR)/*.dep