1diff -u a/Makefile b/Makefile
2--- a/Makefile 2011-05-14 22:24:57.000000000 -0400
3+++ b/Makefile 2016-04-01 14:53:05.000000000 -0400
4@@ -19,9 +19,9 @@
5
6 #****************************************************************************
7
8-CC := gcc
9-CXX := g++
10-LD := g++
11+CC ?= gcc
12+CXX ?= g++
13+LD ?= g++
14 AR := ar rc
15 RANLIB := ranlib
16
17Common subdirectories: a/docs and b/docs