From 7750a461aa55eacbe2eccad2651abb14dcbf5f6a Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 3 Oct 2018 10:56:47 +0530
Subject: [PATCH] Fix compilation on systems that dont have the memfd_create
 syscall

---
 glfw/memfd.h     |  2 +-
 glfw/wl_window.c |  2 +-
 setup.py         | 18 ++++++++++++------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/glfw/memfd.h b/glfw/memfd.h
index 06686314a..bdaa29808 100644
--- a/glfw/memfd.h
+++ b/glfw/memfd.h
@@ -6,7 +6,7 @@
 
 #pragma once
 
-#if defined(__linux__)
+#ifdef HAS_MEMFD_CREATE
 
 #define _GNU_SOURCE
 #include <unistd.h>
diff --git a/glfw/wl_window.c b/glfw/wl_window.c
index 525b3d959..62314a528 100644
--- a/glfw/wl_window.c
+++ b/glfw/wl_window.c
@@ -140,7 +140,7 @@ static int
 createAnonymousFile(off_t size)
 {
     int ret;
-#if defined(__linux__)
+#ifdef HAS_MEMFD_CREATE
     int fd = memfd_create("glfw-shared", MFD_CLOEXEC | MFD_ALLOW_SEALING);
     if (fd < 0) return -1;
     // We can add this seal before calling posix_fallocate(), as the file
diff --git a/setup.py b/setup.py
index 820fdc560..982a3b8b5 100755
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,6 @@ import shutil
 import subprocess
 import sys
 import sysconfig
-import tempfile
 import time
 
 base = os.path.dirname(os.path.abspath(__file__))
@@ -141,11 +140,10 @@ def get_sanitize_args(cc, ccver):
 
 
 def test_compile(cc, *cflags, src=None):
-    with tempfile.NamedTemporaryFile(suffix='.c') as f:
-        src = src or 'int main(void) { return 0; }'
-        f.write(src.encode('utf-8'))
-        f.flush()
-        return subprocess.Popen([cc] + list(cflags) + [f.name, '-o', os.devnull]).wait() == 0
+    src = src or 'int main(void) { return 0; }'
+    p = subprocess.Popen([cc] + list(cflags) + ['-x', 'c', '-o', os.devnull, '-'], stdin=subprocess.PIPE)
+    p.stdin.write(src.encode('utf-8')), p.stdin.close()
+    return p.wait() == 0
 
 
 def first_successful_compile(cc, *cflags, src=None):
@@ -171,6 +169,12 @@ def init_env(
     cc, ccver = cc_version()
     print('CC:', cc, ccver)
     stack_protector = first_successful_compile(cc, '-fstack-protector-strong', '-fstack-protector')
+    has_memfd_create = test_compile(cc, '-Werror', src='''#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+int main(void) {
+    return syscall(__NR_memfd_create, "test", 0);
+}''')
     missing_braces = ''
     if ccver < (5, 2) and cc == 'gcc':
         missing_braces = '-Wno-missing-braces'
@@ -220,6 +224,8 @@ def init_env(
         cflags.append('-g3')
         ldflags.append('-lprofiler')
     ldpaths = []
+    if has_memfd_create:
+        cppflags.append('-DHAS_MEMFD_CREATE')
     return Env(cc, cppflags, cflags, ldflags, ldpaths=ldpaths)