dart:io | Add Directory.CreateSystemTemp(template) and change Directory.CreateTemp(template).

runtime/bin/directory_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/directory.h"
 
 #include <dirent.h>  // NOLINT
@@ skipping 343 matching lines @@
   // process umask.
   int result = TEMP_FAILURE_RETRY(mkdir(dir_name, 0777));
   // If the directory already exists, treat it as a success.
   if (result == -1 && errno == EEXIST) {
     return (Exists(dir_name) == EXISTS);
   }
   return (result == 0);
 }
 
 
-char* Directory::CreateTemp(const char* const_template) {
+char* Directory::CreateTemp(const char* const_template, bool system) {
   // Returns a new, unused directory name, modifying the contents of
   // dir_template.  Creates the directory with the permissions specified
   // by the process umask.
   // The return value must be freed by the caller.
   PathBuffer path;
+  if (system) {
+    const char* temp_dir = getenv("TMPDIR");
+    if (temp_dir == NULL) {
+      temp_dir = getenv("TMP");
+    }
+    if (temp_dir != NULL) {
+      path.Add(temp_dir);
+      if (temp_dir[strlen(temp_dir) - 1] != '/') {
+        path.Add("/");
+      }
+    } else {
+      path.Add("/tmp/");
+    }
+  }
   path.Add(const_template);
-  if (path.length() == 0) {
-    path.Add("/tmp/temp_dir1_");
-  } else if ((path.AsString())[path.length() - 1] == '/') {
-    path.Add("temp_dir_");
-  }
   if (!path.Add("XXXXXX")) {
     // Pattern has overflowed.
     return NULL;
   }
   char* result;
   do {
     result = mkdtemp(path.AsString());
   } while (result == NULL && errno == EINTR);
   if (result == NULL) {
     return NULL;
   }
-  int length = strlen(path.AsString());
+  int length = strnlen(path.AsString(), PATH_MAX);
   result = static_cast<char*>(malloc(length + 1));
   strncpy(result, path.AsString(), length);
   result[length] = '\0';
   return result;
 }
 
 
 bool Directory::Delete(const char* dir_name, bool recursive) {
   if (!recursive) {
     if (File::GetType(dir_name, false) == File::kIsLink &&
@@ skipping 14 matching lines @@
 bool Directory::Rename(const char* path, const char* new_path) {
   ExistsResult exists = Exists(path);
   if (exists != EXISTS) return false;
   return (TEMP_FAILURE_RETRY(rename(path, new_path)) == 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)