From 1fe7b016699c4e2a7435ba29d1ecc6830ae88946 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <7226587+thufschmitt@users.noreply.github.com>
Date: Fri, 9 Feb 2024 06:27:24 +0100
Subject: [PATCH] Don't hardcode the `-O2` compiler flag

autoconf authors apparently decided that setting `-O2` by default was a good idea. I disagree, and Nix has its own way of deciding that (with `OPTIMIZE={0,1}`). Explicitly set `CFLAGS` and `CXXFLAGS` in the configure script to disable that behaviour.

Fix #9965
---
 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index 8c29c1e62..676b145a5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -47,6 +47,10 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier ('cpu-os')])
 # State should be stored in /nix/var, unless the user overrides it explicitly.
 test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var
 
+# Assign a default value to C{,XX}FLAGS as the default configure script sets them
+# to -O2 otherwise, which we don't want to have hardcoded
+CFLAGS=${CFLAGS-""}
+CXXFLAGS=${CXXFLAGS-""}
 
 AC_PROG_CC
 AC_PROG_CXX