Fix UB function problems for AA merger.

src/core/SkAAClip.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAAClip.h"
 #include "SkAtomics.h"
@@ skipping 2038 matching lines @@
 
 static inline uint16_t mergeOne(uint16_t value, unsigned alpha) {
     unsigned r = SkGetPackedR16(value);
     unsigned g = SkGetPackedG16(value);
     unsigned b = SkGetPackedB16(value);
     return SkPackRGB16(SkMulDiv255Round(r, alpha),
                        SkMulDiv255Round(g, alpha),
                        SkMulDiv255Round(b, alpha));
 }
 
-template <typename T> void mergeT(const T* SK_RESTRICT src, int srcN,
-                                 const uint8_t* SK_RESTRICT row, int rowN,
-                                 T* SK_RESTRICT dst) {
+template <typename T>
+void mergeT(const void* inSrc, int srcN, const uint8_t* SK_RESTRICT row, int rowN, void* inDst) {
+    const T* SK_RESTRICT src = static_cast<const T*>(inSrc);
+    T* SK_RESTRICT       dst = static_cast<T*>(inDst);
     for (;;) {
         SkASSERT(rowN > 0);
         SkASSERT(srcN > 0);
 
         int n = SkMin32(rowN, srcN);
         unsigned rowA = row[1];
         if (0xFF == rowA) {
             small_memcpy(dst, src, n * sizeof(T));
         } else if (0 == rowA) {
             small_bzero(dst, n * sizeof(T));
@@ skipping 15 matching lines @@
         rowN = row[0];
     }
 }
 
 static MergeAAProc find_merge_aa_proc(SkMask::Format format) {
     switch (format) {
         case SkMask::kBW_Format:
             SkDEBUGFAIL("unsupported");
             return nullptr;
         case SkMask::kA8_Format:
-        case SkMask::k3D_Format: {
-            void (*proc8)(const uint8_t*, int, const uint8_t*, int, uint8_t*) = mergeT;
-            return (MergeAAProc)proc8;
-        }
-        case SkMask::kLCD16_Format: {
-            void (*proc16)(const uint16_t*, int, const uint8_t*, int, uint16_t*) = mergeT;
-            return (MergeAAProc)proc16;
-        }
+        case SkMask::k3D_Format:
+            return mergeT<uint8_t> ;
+        case SkMask::kLCD16_Format:
+            return mergeT<uint16_t>;
         default:
             SkDEBUGFAIL("unsupported");
             return nullptr;
     }
 }
 
 static U8CPU bit2byte(int bitInAByte) {
     SkASSERT(bitInAByte <= 0xFF);
     // negation turns any non-zero into 0xFFFFFF??, so we just shift down
     // some value >= 8 to get a full FF value
@@ skipping 100 matching lines @@
             rowMask.fBounds.fBottom = y + 1;
             fBlitter->blitMask(rowMask, rowMask.fBounds);
             src = (const void*)((const char*)src + srcRB);
         } while (++y < localStopY);
     } while (y < stopY);
 }
 
 const SkPixmap* SkAAClipBlitter::justAnOpaqueColor(uint32_t* value) {
     return nullptr;
 }