Makefile: generate dependencies also for YACC- and LEX-generated files

We need explicit rules to compile lex.yy.c and y.tab.c for the relaxed
CFLAGS. However, this means that the implicit rule was not used and
therefore no dependencies were generated.

Makefile

@@ -1,8 +1,8 @@
 #
 # Makefile - Makefile of fped, the footprint editor
 #
-# Written 2009-2011 by Werner Almesberger
-# Copyright 2009-2011 by Werner Almesberger
+# Written 2009-2012 by Werner Almesberger
+# Copyright 2009-2012 by Werner Almesberger
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -49,6 +49,12 @@ YYFLAGS = -v
 GIT_VERSION:=$(shell git rev-parse HEAD | cut -c 1-7)
 GIT_STATUS:=$(shell [ -z "`git status -s -uno`" ] || echo +)
 
+MKDEP = $(DEPEND) $(1).c | \
+	sed -e \
+	'/^\(.*:\)\? */{p;s///;s/ *\\\?$$/ /;s/  */:\n/g;H;}' \
+	  -e '$${g;p;}' -e d >$(1).d; \
+	[ "$${PIPESTATUS[*]}" = "0 0" ] || { rm -f $(1).d; exit 1; }
+
 
 # ----- Verbosity control -----------------------------------------------------
 
@@ -92,11 +98,7 @@ endif
 
 %.o:		%.c
 		$(CC) -c $(CFLAGS) $*.c -o $*.o
-		$(DEPEND) $*.c | \
-		  sed -e \
-		    '/^\(.*:\)\? */{p;s///;s/ *\\\?$$/ /;s/  */:\n/g;H;}' \
-		    -e '$${g;p;}' -e d >$*.d; \
-		  [ "$${PIPESTATUS[*]}" = "0 0" ] || { rm -f $*.d; exit 1; }
+		$(call MKDEP, $*)
 
 # generate 26x26 pixels icons, then drop the 1-pixel frame
 
@@ -123,12 +125,14 @@ lex.yy.c:	fpd.l y.tab.h
 
 lex.yy.o:	lex.yy.c y.tab.h
 		$(CC) -c $(CFLAGS) $(SLOPPY) lex.yy.c
+		$(call MKDEP, lex.yy)
 
 y.tab.c y.tab.h: fpd.y
 		$(YACC) $(YYFLAGS) -d fpd.y
 
 y.tab.o:	y.tab.c
 		$(CC) -c $(CFLAGS) $(SLOPPY) y.tab.c
+		$(call MKDEP, y.tab)
 
 gui_tool.o gui.o: $(XPMS:%=icons/%)