Error reporting on File in dart:io

runtime/bin/file_win.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 "bin/file.h"
 
 #include <fcntl.h>
 #include <io.h>
 #include <stdio.h>
 #include <string.h>
@@ skipping 149 matching lines @@
 bool File::IsAbsolutePath(const char* pathname) {
   // Should we consider network paths?
   if (pathname == NULL) return false;
   return (strlen(pathname) > 2) &&
       (pathname[1] == ':') &&
       (pathname[2] == '\\');
 }
 
 
 char* File::GetCanonicalPath(const char* pathname) {
+  struct stat st;
+  if (stat(pathname, &st) != 0) {
+    SetLastError(ERROR_FILE_NOT_FOUND);
+    return NULL;
+  }
   int required_size = GetFullPathName(pathname, 0, NULL, NULL);
   char* path = static_cast<char*>(malloc(required_size));
   int written = GetFullPathName(pathname, required_size, path, NULL);
   ASSERT(written == (required_size - 1));
   return path;
 }
 
 
 char* File::GetContainingDirectory(char* pathname) {
+  struct stat st;
+  if (stat(pathname, &st) == 0) {
+    if ((st.st_mode & S_IFMT) != S_IFREG) {
+      SetLastError(ERROR_FILE_NOT_FOUND);
+      return NULL;
+    }
+  } else {
+    SetLastError(ERROR_FILE_NOT_FOUND);
+    return NULL;
+  }
   int required_size = GetFullPathName(pathname, 0, NULL, NULL);
   char* path = static_cast<char*>(malloc(required_size));
   char* file_part = NULL;
   int written = GetFullPathName(pathname, required_size, path, &file_part);
   ASSERT(written == (required_size - 1));
   ASSERT(file_part != NULL);
   ASSERT(file_part > path);
   ASSERT(file_part[-1] == '\\');
   file_part[-1] = '\0';
   return path;
 }
 
 
 const char* File::PathSeparator() {
   return "\\";
 }
 
 
 const char* File::StringEscapedPathSeparator() {
   return "\\\\";
 }
 
 
 File::StdioHandleType File::GetStdioHandleType(int fd) {
   // Treat all stdio handles as pipes. The Windows event handler and
   // socket code will handle the different handle types.
   return kPipe;
 }