Initial error handling code

src/core/SkXfermode.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkXfermode.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 #include "SkMathPriv.h"
 #include "SkString.h"
+#include "SkValidationUtils.h"
 
 SK_DEFINE_INST_COUNT(SkXfermode)
 
 #define SkAlphaMulAlpha(a, b)   SkMulDiv255Round(a, b)
 
 #if 0
 // idea for higher precision blends in xfer procs (and slightly faster)
 // see DstATop as a probable caller
 static U8CPU mulmuldiv255round(U8CPU a, U8CPU b, U8CPU c, U8CPU d) {
     SkASSERT(a <= 255);
@@ skipping 1370 matching lines @@
         return false;
     }
 #endif
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkProcCoeffXfermode)
 
 protected:
     SkProcCoeffXfermode(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
         fMode = (SkXfermode::Mode)buffer.read32();
-
-        const ProcCoeff& rec = gProcCoeffs[fMode];
-        // these may be valid, or may be CANNOT_USE_COEFF
-        fSrcCoeff = rec.fSC;
-        fDstCoeff = rec.fDC;
-        // now update our function-ptr in the super class
-        this->INHERITED::setProc(rec.fProc);
+        bool modeIsValid = SkIsValidMode(fMode);
+        if (modeIsValid) {
+            const ProcCoeff& rec = gProcCoeffs[fMode];
+            // these may be valid, or may be CANNOT_USE_COEFF
+            fSrcCoeff = rec.fSC;
+            fDstCoeff = rec.fDC;
+            // now update our function-ptr in the super class
+            this->INHERITED::setProc(rec.fProc);
+        } else {
+            fSrcCoeff = fDstCoeff = CANNOT_USE_COEFF;
+        }
+        buffer.validate(modeIsValid &&
+                        (SkIsValidCoeff(fSrcCoeff) || (fSrcCoeff == CANNOT_USE_COEFF)) &&
+                        (SkIsValidCoeff(fDstCoeff) || (fDstCoeff == CANNOT_USE_COEFF)));
     }
 
     virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.write32(fMode);
     }
 
 private:
     Mode    fMode;
     Coeff   fSrcCoeff, fDstCoeff;
@@ skipping 552 matching lines @@
     return proc16;
 }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkClearXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSrcXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstInXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstOutXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END