Implement File::Map on Windows.

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 "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/file.h"
 
 #include <fcntl.h>  // NOLINT
@@ skipping 56 matching lines @@
 intptr_t File::GetFD() {
   return handle_->fd();
 }
 
 
 bool File::IsClosed() {
   return handle_->fd() == kClosedFd;
 }
 
 
-void* File::Map(MapType type, int64_t position, int64_t length) {
-  UNIMPLEMENTED();
-  return NULL;
+void* File::Map(File::MapType type, int64_t position, int64_t length) {
+  DWORD prot_alloc;
+  DWORD prot_final;
+  switch (type) {
+    case File::kReadOnly:
+      prot_alloc = PAGE_READWRITE;
+      prot_final = PAGE_READONLY;
+      break;
+    case File::kReadExecute:
+      prot_alloc = PAGE_EXECUTE_READWRITE;
+      prot_final = PAGE_EXECUTE_READ;
+      break;
+    default:
+      return NULL;
+  }
+
+  void* addr = VirtualAlloc(NULL, length, MEM_COMMIT | MEM_RESERVE, prot_alloc);
+  if (addr == NULL) {
+    Log::PrintErr("VirtualAlloc failed %d\n", GetLastError());
+    return NULL;
+  }
+
+  SetPosition(position);
+  if (!ReadFully(addr, length)) {
+    Log::PrintErr("ReadFully failed %d\n", GetLastError());
+    VirtualFree(addr, 0, MEM_RELEASE);
+    return NULL;
+  }
+
+  DWORD old_prot;
+  bool result = VirtualProtect(addr, length, prot_final, &old_prot);
+  if (!result) {
+    Log::PrintErr("VirtualProtect failed %d\n", GetLastError());
+    VirtualFree(addr, 0, MEM_RELEASE);
+    return NULL;
+  }
+  return addr;
 }
 
 
 int64_t File::Read(void* buffer, int64_t num_bytes) {
   ASSERT(handle_->fd() >= 0);
   return read(handle_->fd(), buffer, num_bytes);
 }
 
 
 int64_t File::Write(const void* buffer, int64_t num_bytes) {
@@ skipping 610 matching lines @@
     return kIdentical;
   } else {
     return kDifferent;
   }
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)