Bug: https://bugs.gentoo.org/882887
From: https://github.com/erlang/otp/pull/6504
From: Florian Weimer <fweimer@redhat.com>
Date: Thu, 24 Nov 2022 11:57:49 +0100
Subject: [PATCH 1/2] configure.ac: C99 fix for
 ERTS___AFTER_MORECORE_HOOK_CAN_TRACK_MALLOC

#include <unistd.h> for the sbrk function if the header is available.
--- a/erts/configure
+++ b/erts/configure
@@ -20752,6 +20752,9 @@ else $as_nop
 #ifdef HAVE_MALLOC_H
 #  include <malloc.h>
 #endif
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
 #if defined(HAVE_END_SYMBOL)
 extern char end;
 #elif defined(HAVE__END_SYMBOL)
--- a/erts/configure.ac
+++ b/erts/configure.ac
@@ -2436,6 +2436,9 @@ AC_CACHE_CHECK([if __after_morecore_hook can track malloc()s core memory use],
 #ifdef HAVE_MALLOC_H
 #  include <malloc.h>
 #endif
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
 #if defined(HAVE_END_SYMBOL)
 extern char end;
 #elif defined(HAVE__END_SYMBOL)

From 7b720d2bb9e742110ff90ec2495747b2c477e2c7 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Thu, 24 Nov 2022 11:59:22 +0100
Subject: [PATCH 2/2] configure.ac: C99 fixes for poll_works check

Include <fcntl.h> if it is available for the open prototype.
Return from main instead of calling exit, so that no function
declaration is needed.
--- a/erts/configure
+++ b/erts/configure
@@ -24663,10 +24663,13 @@ else $as_nop
 /* end confdefs.h.  */
 
 #include <poll.h>
-main()
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+int main()
 {
 #ifdef _POLL_EMUL_H_
-  exit(1); /* Implemented using select() -- fail */
+  return 1; /* Implemented using select() -- fail */
 #else
   struct pollfd fds[1];
   int fd;
@@ -24675,9 +24678,9 @@ main()
   fds[0].events = POLLIN;
   fds[0].revents = 0;
   if (poll(fds, 1, 0) < 0 || (fds[0].revents & POLLNVAL) != 0) {
-    exit(1);  /* Does not work for devices -- fail */
+    return 1;  /* Does not work for devices -- fail */
   }
-  exit(0);
+  return 0;
 #endif
 }
 
--- a/erts/configure.ac
+++ b/erts/configure.ac
@@ -3036,10 +3036,13 @@ poll_works=no
 
 AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <poll.h>
-main()
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+int main()
 {
 #ifdef _POLL_EMUL_H_
-  exit(1); /* Implemented using select() -- fail */
+  return 1; /* Implemented using select() -- fail */
 #else
   struct pollfd fds[1];
   int fd;
@@ -3048,9 +3051,9 @@ main()
   fds[0].events = POLLIN;
   fds[0].revents = 0;
   if (poll(fds, 1, 0) < 0 || (fds[0].revents & POLLNVAL) != 0) {
-    exit(1);  /* Does not work for devices -- fail */
+    return 1;  /* Does not work for devices -- fail */
   }
-  exit(0);
+  return 0;
 #endif
 }
 ]])],[poll_works=yes],[poll_works=no],[