From 4cb1cd6e5765918f7eaad82a3370b693125e892b Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Fri, 1 Dec 2023 04:39:56 +0100
Subject: [PATCH] Makefile: prefer distro cflags if specified

The compilation flags that are necessary for building and part of the
developer's intentions belong in the `+=` section, but the base flags
that distros like to override belong in a `?=` section, so that build
systems using their own are respected.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 src/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Makefile b/src/Makefile
index 2c9d51b..bba8d42 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -12,7 +12,8 @@ VERSION := $(shell \
 DEPDIR := .deps
 DEPFLAGS = -MT $@ -MMD -MP -MF $(DEPDIR)/$*.d
 
-CFLAGS += -Wall -Werror -ggdb -fno-omit-frame-pointer -O2 -D_FORTIFY_SOURCE=2
+CFLAGS ?= -ggdb -fno-omit-frame-pointer -O2
+CFLAGS += -Wall -Werror -D_FORTIFY_SOURCE=2
 CFLAGS += -DVERSION=\"$(VERSION)\"
 CFLAGS += -Wno-error=deprecated-declarations