From fef3b16dba2c5f6ad88951b80cdfbedd423e80a0 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Wed, 7 Dec 2022 20:16:52 -0800
Subject: [PATCH v3 1/3] configure: use AC_SYS_LARGEFILE

The autoconf macro AC_SYS_LARGEFILE defines _FILE_OFFSET_BITS=64
where necessary to ensure that off_t and all interfaces using off_t
are 64bit, even on 32bit systems.

Pass -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=66 via CFLAGS

Upstream-Status: Submitted [https://lore.kernel.org/linux-erofs/20221215064758.93821-1-raj.khem@gmail.com/T/#t]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 configure.ac | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/configure.ac b/configure.ac
index a736ff0..e8bb003 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,6 +13,8 @@ AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_AUX_DIR(config)
 AM_INIT_AUTOMAKE([foreign -Wall])
 
+AC_SYS_LARGEFILE
+
 # Checks for programs.
 AM_PROG_AR
 AC_PROG_CC
@@ -319,6 +321,9 @@ if test "x$enable_lzma" = "xyes"; then
   CPPFLAGS="${saved_CPPFLAGS}"
 fi
 
+# Enable 64-bit off_t
+CFLAGS+=" -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
+
 # Set up needed symbols, conditionals and compiler/linker flags
 AM_CONDITIONAL([ENABLE_LZ4], [test "x${have_lz4}" = "xyes"])
 AM_CONDITIONAL([ENABLE_LZ4HC], [test "x${have_lz4hc}" = "xyes"])
-- 
2.39.0