From dce5c6f33378a1102b7916698bc8f6a9d3eebd7f Mon Sep 17 00:00:00 2001
From: ken <ken@mihrtec.com>
Date: Fri, 16 Dec 2016 11:55:01 -0800
Subject: [PATCH] Makefile v1.0

---
 Makefile | 44 +++++++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/Makefile b/Makefile
index 7968b66..e10f81c 100644
--- a/Makefile
+++ b/Makefile
@@ -5,20 +5,24 @@
 ################################################################################
 # 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    = $(YACC) $(YFLAGS) $<
+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    = $(RLC) $(RLFLAGS) -o $@ $<
+RLCMD    = $(strip $(RLC) $(RLFLAGS) $(if $2,-o $2 $(dir $2))$1)
 
 # C
 CC     ?= gcc
 CFLAGS ?= -Wall
-CCMD    = $(CC) $(CFLAGS) $(CPPFLAGS) -c -o $@ $<
+CCMD    = $(strip $(CC) $(CFLAGS) $(CPPFLAGS) -c $(if $2,-o $2) $1)
 
 # Linker
 LD        ?= ld
@@ -26,7 +30,7 @@ LDFLAGS   ?=
 LDLIBS    ?= -lunistring
 apcLIBS   ?= 
 apc-dLIBS ?= 
-LDCMD      = $(LD) $(LDFLAGS) $(LDLIBS) $($1LIBS) -o $@ $^
+LDCMD      = $(strip $(LD) $(LDFLAGS) $(LDLIBS) $($1LIBS) $(if $2,-o $2) $1)
 
 # APC is built from Ragel, Bison and C source code only.
 ySRC  := $(shell find ./src -type f -name '*.y')
@@ -37,30 +41,36 @@ cSRC  := $(shell find ./src -type f -name '*.c')
 hGEN  := $(ySRC:%.y=%.tab.h)
 cGEN  := $(strip $(ySRC:%.y=%.tab.c) $(rlSRC:%.rl=%.c))
 
-# Deps generation function
-cGENDEP = $(if $(wildcard $1),$(subst $(dir $1),,$(filter-out $1 \ %:,$(shell $(CC) -MM -MG $1))),$(info <$1>))
-
-# Driver sources
-DRIVERS  := apc testapc
+# Filter all other driver objects out of each driver's link commands.
 $(foreach drv,$(DRIVERS),\
 $(eval $(drv)SRC   := $(patsubst %.c,%.o,$(filter-out $(patsubst %,src/%.c,$(filter-out $(drv),$(DRIVERS))),$(cSRC) $(cGEN))))\
 $(eval $(drv)-dSRC := $(patsubst %.o,%-d.o,$($(drv)SRC))))
 
+# Unless cleaning, deps should be generated for each source file
+ifeq (,$(filter clean,$(MAKECMDGOALS)))
+cGENDEP = $(if $(wildcard $1),$(subst $(dir $1),,$(filter-out $1 \ %:,$(shell $(CC) -MM -MG $1))),\
+$(info [<$1>: no deps - file not found]))
+endif
+
+# Construct the S2S function for generating source files during prerequisite
+# expansion:
+# If we are cleaning, stop.  Else print the result of calling '1'.  Then, unless
+# we are in -n mode, invoke the result of calling '1' in the shell
+$(if $(filter clean,$(MAKECMDGOALS)),,$(eval S2S += $$(info $$(call $$1,$$2,$$3)))\
+$(if $(filter n,$(MAKEFLAGS)),,$(eval S2S += $$(shell $$(call $$1,$$2,$$3)))))
+
 # Rules
 .SECONDEXPANSION:
 $(DRIVERS:%=%-d) $(DRIVERS): $$($$@SRC) | $(hGEN)
-	$(strip $(call LDCMD,$@))
+	$(strip $(call LDCMD,$^,$@))
 
 %-d.o: CFLAGS+= -Og -ggdb
 %.o %-d.o: %.c $$(call cGENDEP,$$(dir $$@)%.c)
-	$(strip $(CCMD))
-
-%.tab.h %.tab.c: %.y
-	$(strip $(YCMD))
-	mv $(notdir $(<:%.y=%.tab.[ch])) $(dir $@)
+	$(call CCMD,$<,$@)
 
-%.c: %.rl
-	$(strip $(RLCMD))
+%.tab.h: %.tab.c ;
+%.tab.c: %.y $$(call S2S,YCMD,%.y,$$@) ;
+%.c: %.rl $$(call S2S,RLCMD,%.rl,$$@) ;
 
 clean: $(wildcard $(cGEN) $(hGEN) $(apcSRC) $(apc-dSRC))
 	$(if $^,rm $^)
-- 
2.18.0