--- makefile.orig	Mon Apr 30 08:10:40 2007
+++ makefile	Mon Jul  2 18:32:10 2007
@@ -22,20 +22,11 @@
 # THIS SOFTWARE.
 # ****************************************************************/
 
-CFLAGS = -g
-CFLAGS = -O2
-CFLAGS =
+CFLAGS ?= -O2
 
-CC = gcc -Wall -g -Wwrite-strings
-CC = gcc -fprofile-arcs -ftest-coverage # then gcov f1.c; cat f1.c.gcov
-CC = gcc -Wall -g
-CC = cc
-CC = gcc -O4
-CC = gcc -Wall -g
+CC ?= cc
 
-
-YACC = bison -y
-YACC = yacc
+YACC ?= yacc
 YFLAGS = -d
 
 OFILES = b.o main.o parse.o proctab.o tran.o lib.o run.o lex.o