From 3248cfa49bcfe57ba82efbb18e0318e7b5a315ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Thu, 21 Apr 2022 14:25:51 +0300
Subject: [PATCH 069/N] configure: Include a header in the check for
 _beginthread

Previously, the test tried compiling a call to the
_beginthread function without either declaring the function
(and its parameters) or including the corresponding header.

Since Clang 15 (which still is under development, so this may
still change before it's released) [1], implicit function
declarations are a hard error by default, when building code
in C99 mode (or newer).

[1] https://github.com/llvm/llvm-project/commit/7d644e1215b376ec5e915df9ea2eeb56e2d94626
---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 01086b2..7f5196d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2981,7 +2981,7 @@ AC_MSG_RESULT([$with_nt_threads])
 if test $with_nt_threads = yes ; then
 AC_MSG_CHECKING([whether linking with nt-threads work])
 AC_LINK_IFELSE([
-    AC_LANG_PROGRAM([[]],[[_beginthread(0, 0, 0);]])
+    AC_LANG_PROGRAM([[#include <process.h>]],[[_beginthread(0, 0, 0);]])
   ],
   [AC_MSG_RESULT([yes])],
   [AC_MSG_ERROR([failed to link with nt-threads])])
