From 36991485d4cd2f184d71daa14af301e64f86fdf4 Mon Sep 17 00:00:00 2001
From: k0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 6 Feb 2018 16:57:46 +0000
Subject: [PATCH] mjit.c: make null device portable

for future mswin support

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62266 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 mjit.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/mjit.c b/mjit.c
index 8163d41442..7541be6213 100644
--- a/mjit.c
+++ b/mjit.c
@@ -198,6 +198,8 @@ static char *header_file;
 static char *pch_file;
 /* Path of "/tmp", which can be changed to $TMP in MinGW. */
 static char *tmp_dir;
+/* Portable /dev/null, fetched from file.c */
+static char *null_device;
 /* Hash like { 1 => true, 2 => true, ... } whose keys are valid `class_serial`s.
    This is used to invalidate obsoleted CALL_CACHE. */
 static VALUE valid_class_serials;
@@ -321,7 +323,7 @@ start_process(const char *path, char *const *argv)
 #else
     {
         /* Not calling IO functions between fork and exec for safety */
-        FILE *f = fopen("/dev/null", "w");
+        FILE *f = fopen(null_device, "w");
         int dev_null = fileno(f);
         fclose(f);
 
@@ -1171,6 +1173,10 @@ mjit_init(struct mjit_options *opts)
     else {
         tmp_dir = get_string("/tmp");
     }
+    {
+        VALUE file_null = rb_const_get(rb_cFile, rb_intern("NULL"));
+        null_device = get_string(StringValuePtr(file_null));
+    }
 
     init_header_filename();
     pch_file = get_uniq_filename(0, MJIT_TMP_PREFIX "h", ".h.gch");
@@ -1255,6 +1261,7 @@ mjit_finish(void)
         remove(pch_file);
 
     xfree(tmp_dir); tmp_dir = NULL;
+    xfree(null_device); null_device = NULL;
     xfree(pch_file); pch_file = NULL;
     xfree(header_file); header_file = NULL;