From 90693c6d045b8af9854d347605dd9b437680ddf6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89rico=20Nogueira?= <erico.rolim@lnls.br>
Date: Wed, 26 Jul 2023 10:12:29 -0300
Subject: [PATCH] Fix build on older glibc versions.

_POSIX_C_SOURCE is necessary for getopt(3), and _DEFAULT_SOURCE is
necessary for the d_type enumerations in struct dirent.

Since we are here, use the C11 standard explicitly.

These fixes only allow us to build with glibc>=2.28, which is when the
<threads.h> header was added [1], necessary to access the thread_local
macro.

[1] https://stackoverflow.com/a/22875599
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 3f8207d..bd814f7 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 OPT = -O2
-CFLAGS = -Wall -Wextra $(OPT)
+CFLAGS = -std=c11 -D_POSIX_C_SOURCE=200809UL -D_DEFAULT_SOURCE -Wall -Wextra $(OPT)
 
 .PHONY: all