From a4bae1bdcd893a5590312fa4716724af3b1b63c0 Mon Sep 17 00:00:00 2001
From: "Matthew R. Becker" <beckermr@users.noreply.github.com>
Date: Wed, 22 Mar 2017 16:22:16 -0500
Subject: [PATCH] ENH more makefile updates (#2133)

This commit proposes a simpler single compiler specification for OSX and *nix. It also let's people override the setting on both systems, not just *nix.
---
 Makefile | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index afb003912..add236f0a 100644
--- a/Makefile
+++ b/Makefile
@@ -31,20 +31,24 @@ include $(DMLC_CORE)/make/dmlc.mk
 # include the plugins
 include $(XGB_PLUGINS)
 
-# use customized config file
-ifndef CC
-export CC  = $(if $(shell which gcc-6),gcc-6,gcc)
-endif
-ifndef CXX
-export CXX = $(if $(shell which g++-6),g++-6,g++)
-endif
-
-# on Mac OS X, force brew gcc-6, since the Xcode c++ fails anyway
-# it is useful for pip install compiling-on-the-fly
+# set compiler defaults for OSX versus *nix
+# let people override either
 OS := $(shell uname)
 ifeq ($(OS), Darwin)
-export CC = $(if $(shell which gcc-6),gcc-6,$(if $(shell which gcc-mp-6), gcc-mp-6, $(if $(shell which gcc), gcc, clang)))
-export CXX = $(if $(shell which g++-6),g++-6,$(if $(shell which g++-mp-6),g++-mp-6, $(if $(shell which g++), g++, clang++)))
+ifndef CC
+export CC = $(if $(shell which clang), clang, gcc)
+endif
+ifndef CXX
+export CXX = $(if $(shell which clang++), clang++, g++)
+endif
+else
+# linux defaults
+ifndef CC
+export CC = gcc
+endif
+ifndef CXX
+export CXX = g++
+endif
 endif
 
 export LDFLAGS= -pthread -lm $(ADD_LDFLAGS) $(DMLC_LDFLAGS) $(PLUGIN_LDFLAGS)