From 6ede1bed89fd9d1c25cc6349722898f084bf5e15 Mon Sep 17 00:00:00 2001
From: proukornew <proukornevv@gmail.com>
Date: Fri, 17 Dec 2021 00:41:29 +0300
Subject: [PATCH] Improve handling of variables set in the make environment

removes duplication on the commandline for example in a profile-build

closes https://github.com/official-stockfish/Stockfish/pull/3859

No functional change
---
 src/Makefile | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index cc9b4201..ff2452d6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -345,9 +345,15 @@ endif
 ### ==========================================================================
 
 ### 3.1 Selecting compiler (default = gcc)
-CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -std=c++17 $(EXTRACXXFLAGS)
-DEPENDFLAGS += -std=c++17
-LDFLAGS += $(EXTRALDFLAGS)
+ifeq ($(MAKELEVEL),0)
+       export ENV_CXXFLAGS := $(CXXFLAGS)
+       export ENV_DEPENDFLAGS := $(DEPENDFLAGS)
+       export ENV_LDFLAGS := $(LDFLAGS)
+endif
+
+CXXFLAGS = $(ENV_CXXFLAGS) -Wall -Wcast-qual -fno-exceptions -std=c++17 $(EXTRACXXFLAGS)
+DEPENDFLAGS = $(ENV_DEPENDFLAGS) -std=c++17
+LDFLAGS = $(ENV_LDFLAGS) $(EXTRALDFLAGS)
 
 ifeq ($(COMP),)
 	COMP=gcc