Bug 1216611 - add mozilla::MakeUniqueFallible and convert uses throughout the tree; r=Waldo

dom/canvas/WebGLContextDraw.cpp

@@ -7,6 +7,7 @@
 
 #include "GLContext.h"
 #include "mozilla/CheckedInt.h"
+#include "mozilla/UniquePtrExtensions.h"
 #include "WebGLBuffer.h"
 #include "WebGLContextUtils.h"
 #include "WebGLFramebuffer.h"
@@ -580,7 +581,7 @@ WebGLContext::DoFakeVertexAttrib0(GLuint vertexCount)
         GetAndFlushUnderlyingGLErrors();
 
         if (mFakeVertexAttrib0BufferStatus == WebGLVertexAttrib0Status::EmulatedInitializedArray) {
-            UniquePtr<GLfloat[]> array(new (fallible) GLfloat[4 * vertexCount]);
+            auto array = MakeUniqueFallible<GLfloat[]>(4 * vertexCount);
             if (!array) {
                 ErrorOutOfMemory("Fake attrib0 array.");
                 return false;

dom/canvas/WebGLContextGL.cpp

@@ -52,6 +52,7 @@
 #include "mozilla/dom/ToJSValue.h"
 #include "mozilla/Endian.h"
 #include "mozilla/RefPtr.h"
+#include "mozilla/UniquePtrExtensions.h"
 
 namespace mozilla {
 
@@ -1622,7 +1623,7 @@ WebGLContext::ReadPixels(GLint x, GLint y, GLsizei width,
         uint32_t subrect_byteLength = (subrect_height-1)*subrect_alignedRowSize + subrect_plainRowSize;
 
         // create subrect buffer, call glReadPixels, copy pixels into destination buffer, delete subrect buffer
-        UniquePtr<GLubyte> subrect_data(new (fallible) GLubyte[subrect_byteLength]);
+        auto subrect_data = MakeUniqueFallible<GLubyte[]>(subrect_byteLength);
         if (!subrect_data)
             return ErrorOutOfMemory("readPixels: subrect_data");
 

gfx/thebes/gfxUtils.cpp

@@ -21,6 +21,7 @@
 #include "mozilla/gfx/Logging.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/RefPtr.h"
+#include "mozilla/UniquePtrExtensions.h"
 #include "mozilla/Vector.h"
 #include "nsComponentManagerUtils.h"
 #include "nsIClipboardHelper.h"
@@ -1560,7 +1561,7 @@ gfxUtils::GetImageBuffer(gfx::DataSourceSurface* aSurface,
         return nullptr;
 
     uint32_t bufferSize = aSurface->GetSize().width * aSurface->GetSize().height * 4;
-    UniquePtr<uint8_t[]> imageBuffer(new (fallible) uint8_t[bufferSize]);
+    auto imageBuffer = MakeUniqueFallible<uint8_t[]>(bufferSize);
     if (!imageBuffer) {
         aSurface->Unmap();
         return nullptr;

image/encoders/bmp/nsBMPEncoder.cpp

@@ -5,6 +5,7 @@
 
 #include "nsCRT.h"
 #include "mozilla/Endian.h"
+#include "mozilla/UniquePtrExtensions.h"
 #include "nsBMPEncoder.h"
 #include "prprf.h"
 #include "nsString.h"
@@ -187,9 +188,8 @@ nsBMPEncoder::AddImageFrame(const uint8_t* aData,
     return NS_ERROR_INVALID_ARG;
   }
 
-  UniquePtr<uint8_t[]> row(new (fallible)
-                           uint8_t[mBMPInfoHeader.width *
-                                   BytesPerPixel(mBMPInfoHeader.bpp)]);
+  auto row = MakeUniqueFallible<uint8_t[]>(mBMPInfoHeader.width *
+                                           BytesPerPixel(mBMPInfoHeader.bpp));
   if (!row) {
     return NS_ERROR_OUT_OF_MEMORY;
   }

media/webrtc/signaling/src/mediapipeline/MediaPipeline.cpp

@@ -45,6 +45,7 @@
 #include "mozilla/gfx/Point.h"
 #include "mozilla/gfx/Types.h"
 #include "mozilla/UniquePtr.h"
+#include "mozilla/UniquePtrExtensions.h"
 
 #include "logging.h"
 
@@ -1179,7 +1180,7 @@ void MediaPipelineTransmit::PipelineListener::ProcessVideoChunk(
   int half_height = (size.height + 1) >> 1;
   int c_size = half_width * half_height;
   int buffer_size = YSIZE(size.width, size.height) + 2 * c_size;
-  UniquePtr<uint8[]> yuv_scoped(new (fallible) uint8[buffer_size]);
+  auto yuv_scoped = MakeUniqueFallible<uint8[]>(buffer_size);
   if (!yuv_scoped)
     return;
   uint8* yuv = yuv_scoped.get();

mfbt/UniquePtrExtensions.h

@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/* Useful extensions to UniquePtr. */
+
+#ifndef mozilla_UniquePtrExtensions_h
+#define mozilla_UniquePtrExtensions_h
+
+#include "mozilla/fallible.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+
+/**
+ * MakeUniqueFallible works exactly like MakeUnique, except that the memory
+ * allocation performed is done fallibly, i.e. it can return nullptr.
+ */
+template<typename T, typename... Args>
+typename detail::UniqueSelector<T>::SingleObject
+MakeUniqueFallible(Args&&... aArgs)
+{
+  return UniquePtr<T>(new (fallible) T(Forward<Args>(aArgs)...));
+}
+
+template<typename T>
+typename detail::UniqueSelector<T>::UnknownBound
+MakeUniqueFallible(decltype(sizeof(int)) aN)
+{
+  typedef typename RemoveExtent<T>::Type ArrayType;
+  return UniquePtr<T>(new (fallible) ArrayType[aN]());
+}
+
+template<typename T, typename... Args>
+typename detail::UniqueSelector<T>::KnownBound
+MakeUniqueFallible(Args&&... aArgs) = delete;
+
+} // namespace mozilla
+
+#endif // mozilla_UniquePtrExtensions_h

mfbt/moz.build

@@ -89,6 +89,7 @@ EXPORTS.mozilla = [
     'Types.h',
     'TypeTraits.h',
     'UniquePtr.h',
+    'UniquePtrExtensions.h',
     'Variant.h',
     'Vector.h',
     'WeakPtr.h',

widget/gtk/nsWindow.cpp

@@ -11,6 +11,7 @@
 #include "mozilla/MouseEvents.h"
 #include "mozilla/TextEvents.h"
 #include "mozilla/TouchEvents.h"
+#include "mozilla/UniquePtrExtensions.h"
 #include <algorithm>
 
 #include "GeckoProfiler.h"
@@ -2322,7 +2323,7 @@ nsWindow::UpdateAlpha(gfxPattern* aPattern, nsIntRect aBoundsRect)
     int32_t stride = GetAlignedStride<4>(BytesPerPixel(SurfaceFormat::A8) *
                                          aBoundsRect.width);
     int32_t bufferSize = stride * aBoundsRect.height;
-    UniquePtr<uint8_t[]> imageBuffer(new (std::nothrow) uint8_t[bufferSize]);
+    auto imageBuffer = MakeUniqueFallible<uint8_t[]>(bufferSize);
     RefPtr<DrawTarget> drawTarget = gfxPlatform::GetPlatform()->
         CreateDrawTargetForData(imageBuffer.get(), aBoundsRect.Size(),
                                 stride, SurfaceFormat::A8);