remove SkRefCnt safeRef() and safeUnref(), and replace the call-sites with

SkSafeRef() and SkSafeUnref().

This is basically a bug waiting to happen. An optimizing compiler can remove
checks for null on "this" if it chooses. However, SkRefCnt::safeRef() relies on
precisely this check...

void SkRefCnt::safeRef() {
    if (this) {
        this->ref();
    }
}

Since a compiler might skip the if-clause, it breaks the intention of this
method, hence its removal.

static inline void SkSafeRef(SkRefCnt* obj) {
    if (obj) {
        obj->ref();
    }
}

This form is not ignored by an optimizing compile, so we use it instead.




git-svn-id: http://skia.googlecode.com/svn/trunk@762 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 56 insertions, 55 deletions

diff --git a/src/core/SkBlitter_4444.cpp b/src/core/SkBlitter_4444.cpp
index 81bbc48cbb..e1c519a313 100644
--- a/src/core/SkBlitter_4444.cpp
+++ b/src/core/SkBlitter_4444.cpp
@@ -2,16 +2,16 @@
  **
  ** Copyright 2006, The Android Open Source Project
  **
- ** Licensed under the Apache License, Version 2.0 (the "License"); 
- ** you may not use this file except in compliance with the License. 
- ** You may obtain a copy of the License at 
+ ** Licensed under the Apache License, Version 2.0 (the "License");
+ ** you may not use this file except in compliance with the License.
+ ** You may obtain a copy of the License at
  **
- **     http://www.apache.org/licenses/LICENSE-2.0 
+ **     http://www.apache.org/licenses/LICENSE-2.0
  **
- ** Unless required by applicable law or agreed to in writing, software 
- ** distributed under the License is distributed on an "AS IS" BASIS, 
- ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
- ** See the License for the specific language governing permissions and 
+ ** Unless required by applicable law or agreed to in writing, software
+ ** distributed under the License is distributed on an "AS IS" BASIS,
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ ** See the License for the specific language governing permissions and
  ** limitations under the License.
  */
 
@@ -23,13 +23,13 @@
 #include "SkUtils.h"
 #include "SkXfermode.h"
 
-inline SkPMColor SkBlendARGB4444(SkPMColor16 src, SkPMColor16 dst, U8CPU aa)
-{
+static inline SkPMColor SkBlendARGB4444(SkPMColor16 src, SkPMColor16 dst,
+                                        U8CPU aa) {
     SkASSERT((unsigned)aa <= 255);
-    
+
     unsigned src_scale = SkAlpha255To256(aa) >> 4;
     unsigned dst_scale = SkAlpha15To16(15 - SkAlphaMul4(SkGetPackedA4444(src), src_scale));
-    
+
     uint32_t src32 = SkExpand_4444(src) * src_scale;
     uint32_t dst32 = SkExpand_4444(dst) * dst_scale;
     return SkCompact_4444((src32 + dst32) >> 4);
@@ -46,16 +46,16 @@ public:
     virtual void blitRect(int x, int y, int width, int height);
     virtual void blitMask(const SkMask&, const SkIRect&);
     virtual const SkBitmap* justAnOpaqueColor(uint32_t*);
-    
+
 protected:
     SkPMColor16 fPMColor16, fPMColor16Other;
     SkPMColor16 fRawColor16, fRawColor16Other;
     uint8_t     fScale16;
-    
+
 private:
     // illegal
     SkARGB4444_Blitter& operator=(const SkARGB4444_Blitter&);
-    
+
     typedef SkRasterBlitter INHERITED;
 };
 
@@ -81,7 +81,7 @@ SkARGB4444_Blitter::SkARGB4444_Blitter(const SkBitmap& device, const SkPaint& pa
     } else {
         fRawColor16Other = fRawColor16;
     }
-    
+
 #if 0 /// don't think this assertion is true, but need it be?
 
     // our dithered color will be the same or more opaque than the original
@@ -146,19 +146,19 @@ static void src_over_4444x(SkPMColor16 dst[], uint32_t color,
 void SkARGB4444_Blitter::blitH(int x, int y, int width)
 {
     SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width());
-    
+
     if (0 == fScale16) {
         return;
     }
-    
+
     SkPMColor16* device = fDevice.getAddr16(x, y);
     SkPMColor16  color = fPMColor16;
     SkPMColor16  other = fPMColor16Other;
-    
+
     if ((x ^ y) & 1) {
         SkTSwap<SkPMColor16>(color, other);
     }
-    
+
     if (16 == fScale16) {
         sk_dither_memset16(device, color, other, width);
     }
@@ -174,12 +174,12 @@ void SkARGB4444_Blitter::blitV(int x, int y, int height, SkAlpha alpha)
     if (0 == alpha || 0 == fScale16) {
         return;
     }
-    
+
     SkPMColor16* device = fDevice.getAddr16(x, y);
     SkPMColor16  color = fPMColor16;
     SkPMColor16  other = fPMColor16Other;
     unsigned     rb = fDevice.rowBytes();
-    
+
     if ((x ^ y) & 1) {
         SkTSwap<SkPMColor16>(color, other);
     }
@@ -211,19 +211,19 @@ void SkARGB4444_Blitter::blitV(int x, int y, int height, SkAlpha alpha)
 void SkARGB4444_Blitter::blitRect(int x, int y, int width, int height)
 {
     SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width() && y + height <= fDevice.height());
-    
+
     if (0 == fScale16) {
         return;
     }
-    
+
     SkPMColor16* device = fDevice.getAddr16(x, y);
     SkPMColor16  color = fPMColor16;
     SkPMColor16  other = fPMColor16Other;
-    
+
     if ((x ^ y) & 1) {
         SkTSwap<SkPMColor16>(color, other);
     }
-    
+
     if (16 == fScale16) {
         while (--height >= 0) {
             sk_dither_memset16(device, color, other, width);
@@ -248,22 +248,22 @@ void SkARGB4444_Blitter::blitAntiH(int x, int y, const SkAlpha antialias[], cons
     if (0 == fScale16) {
         return;
     }
-    
+
     SkPMColor16* device = fDevice.getAddr16(x, y);
     SkPMColor16  color = fPMColor16;
     SkPMColor16  other = fPMColor16Other;
-    
+
     if ((x ^ y) & 1) {
         SkTSwap<SkPMColor16>(color, other);
     }
-    
+
     for (;;) {
         int count = runs[0];
         SkASSERT(count >= 0);
         if (count <= 0) {
             return;
         }
-        
+
         unsigned aa = antialias[0];
         if (aa) {
             if (0xFF == aa) {
@@ -338,11 +338,11 @@ if (mask & 0x01) { dst[7] = sc + SkAlphaMulQ4(dst[7], dst_scale); }  \
 void SkARGB4444_Blitter::blitMask(const SkMask& mask, const SkIRect& clip)
 {
     SkASSERT(mask.fBounds.contains(clip));
-    
+
     if (0 == fScale16) {
         return;
     }
-    
+
     if (mask.fFormat == SkMask::kBW_Format) {
         if (16 == fScale16) {
             SkARGB4444_BlitBW(fDevice, mask, clip, fPMColor16);
@@ -351,18 +351,18 @@ void SkARGB4444_Blitter::blitMask(const SkMask& mask, const SkIRect& clip)
         }
         return;
     }
-    
+
     int x = clip.fLeft;
     int y = clip.fTop;
     int width = clip.width();
     int height = clip.height();
-    
+
     SkPMColor16*    device = fDevice.getAddr16(x, y);
     const uint8_t*  alpha = mask.getAddr(x, y);
     SkPMColor16     srcColor = fPMColor16;
     unsigned        devRB = fDevice.rowBytes() - (width << 1);
     unsigned        maskRB = mask.fRowBytes - width;
-    
+
     do {
         int w = width;
         do {
@@ -384,15 +384,17 @@ class SkARGB4444_Shader_Blitter : public SkShaderBlitter {
     SkPMColor*      fBuffer;
     uint8_t*        fAAExpand;
 public:
+
 SkARGB4444_Shader_Blitter(const SkBitmap& device, const SkPaint& paint)
     : INHERITED(device, paint)
 {
     const int width = device.width();
     fBuffer = (SkPMColor*)sk_malloc_throw(width * sizeof(SkPMColor) + width);
     fAAExpand = (uint8_t*)(fBuffer + width);
-    
-    (fXfermode = paint.getXfermode())->safeRef();
-    
+
+    fXfermode = paint.getXfermode();
+    SkSafeRef(fXfermode);
+
     unsigned flags = 0;
     if (!(fShader->getFlags() & SkShader::kOpaqueAlpha_Flag)) {
         flags |= SkBlitRow::kSrcPixelAlpha_Flag;
@@ -405,41 +407,39 @@ SkARGB4444_Shader_Blitter(const SkBitmap& device, const SkPaint& paint)
                                     SkBitmap::kARGB_4444_Config);
 }
 
-virtual ~SkARGB4444_Shader_Blitter()
-{
-    fXfermode->safeUnref();
+virtual ~SkARGB4444_Shader_Blitter() {
+    SkSafeUnref(fXfermode);
     sk_free(fBuffer);
 }
 
-virtual void blitH(int x, int y, int width)
-{
+virtual void blitH(int x, int y, int width) {
     SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width());
-    
-    SkPMColor16* device = fDevice.getAddr16(x, y);    
+
+    SkPMColor16* device = fDevice.getAddr16(x, y);
     SkPMColor*   span = fBuffer;
-    
+
     fShader->shadeSpan(x, y, span, width);
     if (fXfermode) {
         fXfermode->xfer4444(device, span, width, NULL);
-    }
-    else {
+    } else {
         fOpaqueProc(device, span, width, 0xFF, x, y);
     }
 }
 
-virtual void blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t runs[])
-{
+virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
+                       const int16_t runs[]) {
     SkPMColor* SK_RESTRICT span = fBuffer;
     uint8_t* SK_RESTRICT aaExpand = fAAExpand;
     SkPMColor16* device = fDevice.getAddr16(x, y);
     SkShader*    shader = fShader;
     SkXfermode*  xfer = fXfermode;
-    
+
     if (NULL != xfer) {
         for (;;) {
             int count = *runs;
-            if (count <= 0)
+            if (count <= 0) {
                 break;
+            }
             int aa = *antialias;
             if (aa) {
                 shader->shadeSpan(x, y, span, count);
@@ -458,12 +458,13 @@ virtual void blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t ru
             runs += count;
             antialias += count;
             x += count;
-        } 
+        }
     } else {    // no xfermode
         for (;;) {
             int count = *runs;
-            if (count <= 0)
+            if (count <= 0) {
                 break;
+            }
             int aa = *antialias;
             if (aa) {
                 fShader->shadeSpan(x, y, span, count);
@@ -477,7 +478,7 @@ virtual void blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t ru
             runs += count;
             antialias += count;
             x += count;
-        } 
+        }
     }
 }