1 files changed, 55 insertions, 0 deletions
diff --git a/memory/mozalloc/winheap.cpp b/memory/mozalloc/winheap.cpp
new file mode 100644
index 0000000000..1d2e1e5599
--- /dev/null
+++ b/memory/mozalloc/winheap.cpp
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=4 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/mozalloc.h"
+#include <windows.h>
+
+#if !defined(MOZ_MEMORY)
+#  include <malloc.h>
+#  define malloc_impl malloc
+#  define calloc_impl calloc
+#  define realloc_impl realloc
+#  define free_impl free
+#endif
+
+// Warning: C4273: 'HeapAlloc': inconsistent dll linkage
+// The Windows headers define HeapAlloc as dllimport, but we define it as
+// dllexport, which is a voluntary inconsistency.
+#pragma warning(disable : 4273)
+
+MFBT_API
+LPVOID WINAPI HeapAlloc(_In_ HANDLE hHeap, _In_ DWORD dwFlags,
+                        _In_ SIZE_T dwBytes) {
+  if (dwFlags & HEAP_ZERO_MEMORY) {
+    return calloc_impl(1, dwBytes);
+  }
+  return malloc_impl(dwBytes);
+}
+
+MFBT_API
+LPVOID WINAPI HeapReAlloc(_In_ HANDLE hHeap, _In_ DWORD dwFlags,
+                          _In_ LPVOID lpMem, _In_ SIZE_T dwBytes) {
+  // The HeapReAlloc contract is that failures preserve the existing
+  // allocation. We can't try to realloc in-place without possibly
+  // freeing the original allocation, breaking the contract.
+  // We also can't guarantee we zero all the memory from the end of
+  // the original allocation to the end of the new one because of the
+  // difference between the originally requested size and what
+  // malloc_usable_size would return us.
+  // So for both cases, just tell the caller we can't do what they
+  // requested.
+  if (dwFlags & (HEAP_REALLOC_IN_PLACE_ONLY | HEAP_ZERO_MEMORY)) {
+    return NULL;
+  }
+  return realloc_impl(lpMem, dwBytes);
+}
+
+MFBT_API
+BOOL WINAPI HeapFree(_In_ HANDLE hHeap, _In_ DWORD dwFlags, _In_ LPVOID lpMem) {
+  free_impl(lpMem);
+  return true;
+}