From: Eli Zaretskii <eliz@gnu.org>
Date: Sun, 19 May 2024 07:58:52 +0000 (+0300)
Subject: Fix MinGW build with GCC 14 and later
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=02e7c850bacb7bc0c9ad883ddcc800f43cbc25c2;p=emacs.git

Fix MinGW build with GCC 14 and later

* configure.ac [mingw]: Add -Wno-error=implicit-function-declaration
to GCC_TEST_OPTIONS.  (Bug#70889)

(cherry picked from commit 5216903ae6c3f91ebefb1152af40753f723cbc39)
---

diff --git a/configure.ac b/configure.ac
index 47a657a6d20..9d91e8731b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1493,7 +1493,11 @@ case "${canonical}" in
       *-mingw* )
 		opsys=mingw32
 		# MinGW overrides and adds some system headers in nt/inc.
-		GCC_TEST_OPTIONS="-I $srcdir/nt/inc"
+		# Also, GCC 14 turns on implicit-function-declaration
+		# error by default, which fails configure tests where our
+		# emulation of Posix headers defines only the minimal
+		# stuff we actually need.
+		GCC_TEST_OPTIONS="-I $srcdir/nt/inc -Wno-error=implicit-function-declaration"
 		;;
       *-sysv4.2uw* )		opsys=unixware ;;
       *-sysv5uw* )		opsys=unixware ;;
@@ -1508,7 +1512,7 @@ case "${canonical}" in
       *-mingw* )
 		opsys=mingw32
 		# MinGW overrides and adds some system headers in nt/inc.
-		GCC_TEST_OPTIONS="-I $srcdir/nt/inc"
+		GCC_TEST_OPTIONS="-I $srcdir/nt/inc -Wno-error=implicit-function-declaration"
 		;;
       ## Otherwise, we'll fall through to the generic opsys code at the bottom.
     esac