################################################################################
# Desc:   APC make script
# Author: kgr
# Date:   2016
################################################################################
# This makefile builds APC, the Asset Package Compiler for Henge, on the system.
################################################################################
# Driver sources
DRIVERS  := apc testapc

# Yacc
YACC   := bison
YFLAGS ?= -v -d -Wall
YCMD    = $(strip $(YACC) $(YFLAGS) $(if $2,$(dir $2))$1)
YCMD   += $(if $2,&& mv $(notdir $(1:%.y=%.tab.[ch])) $(dir $2))

# Ragel
RLC     ?= ragel
RLFALGS ?= -C
RLCMD    = $(strip $(RLC) $(RLFLAGS) $(if $2,-o $2 $(dir $2))$1)

# C
CC     ?= gcc
CFLAGS ?= -Wall
CCMD    = $(strip $(CC) $(CFLAGS) $(CPPFLAGS) -c $(if $2,-o $2) $1)

# Linker
LD        ?= ld
LDFLAGS   ?= 
LDLIBS    ?= -lunistring
apcLIBS   ?= 
apc-dLIBS ?= 
LDCMD      = $(strip gcc $(LDFLAGS) $(if $2,-o $2) $1) $(LDLIBS) $($1LIBS) 

# APC is built from Ragel, Bison and C source code only.
ySRC  := $(shell find ./src -type f -name '*.y')
rlSRC := $(shell find ./src -type f -name '*.rl')
cSRC  := $(shell find ./src -type f -name '*.c')

# Generated files from Yacc/Bison and Ragel
hGEN  := $(ySRC:%.y=%.tab.h)
cGEN  := $(strip $(ySRC:%.y=%.tab.c) $(rlSRC:%.rl=%.fsm.c))

# Filter all other driver objects out of each driver's link commands.
OBJ   := $(patsubst %.c,%.o,$(cSRC) $(cGEN))
$(foreach drv,$(DRIVERS),\
$(eval OTHERS      := $(filter-out $(drv),$(DRIVERS)))\
$(eval $(drv)SRC   := $(filter-out $(OTHERS:%=\%/%.o),$(OBJ)))\
$(eval $(drv)-dSRC := $($(drv)SRC:%.o=%-d.o)))

ifeq (,$(filter clean,$(MAKECMDGOALS)))
# Deps should be generated for each source file, when not cleaning
cGENDEP = $(if $(wildcard $1),$(subst $(dir $1),,$(filter-out $1 \ %:,$(shell $(CC) -MM -MG $1))),\
$(info [<$1>: no deps - file not found]))
# S2S will print the command necessary to create a file when called
S2S  = $(info $(call $1,$2,$3))
ifeq (,$(filter n,$(MAKEFLAGS)))
# Unless we're in -n mode, S2S should also invoke the command on the shell
S2S += $(shell $(call $1,$2,$3))
endif
endif

# Rules
.SECONDEXPANSION:
$(DRIVERS:%=%-d) $(DRIVERS): $$($$@SRC) | $(hGEN)
	$(strip $(call LDCMD,$^,$@))

%-d.o: CFLAGS+= -Og -ggdb
%.o %-d.o: %.c $$(call cGENDEP,$$(dir $$@)%.c)
	$(call CCMD,$<,$@)

%.tab.h: %.tab.c ;
%.tab.c: %.y $$(call S2S,YCMD,%.y,$$@) ;
%.fsm.c: %.rl $$(call S2S,RLCMD,%.rl,$$@) ;

clean: $(wildcard $(cGEN) $(hGEN) $(foreach drv,$(DRIVERS),$($(drv)SRC) $($(drv)-dSRC)))
	$(if $^,rm $^)