This moves us towards variable length effect keys. The overall program key now allows for it. After the header it stores an array of offsets to effect keys. This allows us to grab the effect keys to pass to effects when they generate code. It also ensures that we can't get a collision by sets of keys that are different lengths but are the same when appended together.

R=robertphillips@google.com, jvanverth@google.com, egdaniel@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/356513003

8 files changed, 166 insertions, 122 deletions

diff --git a/src/gpu/gl/GrGLEffect.h b/src/gpu/gl/GrGLEffect.h
index 1cc3df24b0..0727372e62 100644
--- a/src/gpu/gl/GrGLEffect.h
+++ b/src/gpu/gl/GrGLEffect.h
@@ -10,10 +10,11 @@
 
 #include "GrBackendEffectFactory.h"
 #include "GrGLProgramEffects.h"
-#include "GrGLShaderBuilder.h"
 #include "GrGLShaderVar.h"
 #include "GrGLSL.h"
 
+class GrGLShaderBuilder;
+
 /** @file
     This file contains specializations for OpenGL of the shader stages declared in
     include/gpu/GrEffect.h. Objects of type GrGLEffect are responsible for emitting the
@@ -43,12 +44,6 @@ public:
     typedef GrGLProgramEffects::TextureSampler TextureSampler;
     typedef GrGLProgramEffects::TextureSamplerArray TextureSamplerArray;
 
-    enum {
-        kNoEffectKey = GrBackendEffectFactory::kNoEffectKey,
-        // the number of bits in EffectKey available to GenKey
-        kEffectKeyBits = GrBackendEffectFactory::kEffectKeyBits,
-    };
-
     GrGLEffect(const GrBackendEffectFactory& factory)
         : fFactory(factory)
         , fIsVertexEffect(false) {
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index ecd48e0148..2c260cda52 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -14,29 +14,28 @@
 
 #include "SkChecksum.h"
 
-namespace {
-inline GrGLEffect::EffectKey get_key_and_update_stats(const GrEffectStage& stage,
-                                                      const GrGLCaps& caps,
-                                                      bool useExplicitLocalCoords,
-                                                      bool* setTrueIfReadsDst,
-                                                      bool* setTrueIfReadsPos,
-                                                      bool* setTrueIfHasVertexCode) {
-    const GrEffect* effect = stage.getEffect();
-    const GrBackendEffectFactory& factory = effect->getFactory();
+static inline bool get_key_and_update_stats(const GrEffectStage& stage,
+                                            const GrGLCaps& caps,
+                                            bool useExplicitLocalCoords,
+                                            GrEffectKeyBuilder* b, 
+                                            bool* setTrueIfReadsDst,
+                                            bool* setTrueIfReadsPos,
+                                            bool* setTrueIfHasVertexCode) {
+    const GrBackendEffectFactory& factory = stage.getEffect()->getFactory();
     GrDrawEffect drawEffect(stage, useExplicitLocalCoords);
-    if (effect->willReadDstColor()) {
+    if (stage.getEffect()->willReadDstColor()) {
         *setTrueIfReadsDst = true;
     }
-    if (effect->willReadFragmentPosition()) {
+    if (stage.getEffect()->willReadFragmentPosition()) {
         *setTrueIfReadsPos = true;
     }
-    if (effect->hasVertexCode()) {
+    if (stage.getEffect()->hasVertexCode()) {
         *setTrueIfHasVertexCode = true;
     }
-    return factory.glEffectKey(drawEffect, caps);
+    return factory.getGLEffectKey(drawEffect, caps, b);
 }
-}
-void GrGLProgramDesc::Build(const GrDrawState& drawState,
+
+bool GrGLProgramDesc::Build(const GrDrawState& drawState,
                             GrGpu::DrawType drawType,
                             GrDrawState::BlendOptFlags blendOpts,
                             GrBlendCoeff srcCoeff,
@@ -94,45 +93,68 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
                              (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
                              (!inputColorIsUsed);
 
-    int numEffects = (skipColor ? 0 : (drawState.numColorStages() - firstEffectiveColorStage)) +
-                     (skipCoverage ? 0 : (drawState.numCoverageStages() - firstEffectiveCoverageStage));
-
-    size_t newKeyLength = KeyLength(numEffects);
-    bool allocChanged;
-    desc->fKey.reset(newKeyLength, SkAutoMalloc::kAlloc_OnShrink, &allocChanged);
-    if (allocChanged || !desc->fInitialized) {
-        // make sure any padding in the header is zero if we we haven't used this allocation before.
-        memset(desc->header(), 0, kHeaderSize);
-    }
-    // write the key length
-    *desc->atOffset<uint32_t, kLengthOffset>() = SkToU32(newKeyLength);
-
-    KeyHeader* header = desc->header();
-    EffectKey* effectKeys = desc->effectKeys();
-
-    int currEffectKey = 0;
     bool readsDst = false;
     bool readFragPosition = false;
     // We use vertexshader-less shader programs only when drawing paths.
     bool hasVertexCode = !(GrGpu::kDrawPath_DrawType == drawType ||
                            GrGpu::kDrawPaths_DrawType == drawType);
+    int numStages = 0;
+    if (!skipColor) {
+        numStages += drawState.numColorStages() - firstEffectiveColorStage;
+    }
+    if (!skipCoverage) {
+        numStages += drawState.numCoverageStages() - firstEffectiveCoverageStage;
+    }
+    GR_STATIC_ASSERT(0 == kEffectKeyLengthsOffset % sizeof(uint32_t));
+    // Make room for everything up to and including the array of offsets to effect keys.
+    desc->fKey.reset();
+    desc->fKey.push_back_n(kEffectKeyLengthsOffset + sizeof(uint32_t) * numStages);
 
+    size_t offset = desc->fKey.count();
+    int offsetIndex = 0;
+
+    bool effectKeySuccess = true;
     if (!skipColor) {
         for (int s = firstEffectiveColorStage; s < drawState.numColorStages(); ++s) {
-            effectKeys[currEffectKey++] =
-                get_key_and_update_stats(drawState.getColorStage(s), gpu->glCaps(),
-                                         requiresLocalCoordAttrib, &readsDst, &readFragPosition,
-                                         &hasVertexCode);
+            uint32_t* offsetLocation = reinterpret_cast<uint32_t*>(desc->fKey.begin() +
+                                                                   kEffectKeyLengthsOffset +
+                                                                   offsetIndex * sizeof(uint32_t));
+            *offsetLocation = offset;
+            ++offsetIndex;
+
+            GrEffectKeyBuilder b(&desc->fKey);
+            effectKeySuccess |= get_key_and_update_stats(drawState.getColorStage(s), gpu->glCaps(),
+                                                         requiresLocalCoordAttrib, &b, &readsDst,
+                                                         &readFragPosition, &hasVertexCode);
+            offset += b.size();
         }
     }
     if (!skipCoverage) {
         for (int s = firstEffectiveCoverageStage; s < drawState.numCoverageStages(); ++s) {
-            effectKeys[currEffectKey++] =
-                get_key_and_update_stats(drawState.getCoverageStage(s), gpu->glCaps(),
-                                         requiresLocalCoordAttrib, &readsDst, &readFragPosition,
-                                         &hasVertexCode);
+            uint32_t* offsetLocation = reinterpret_cast<uint32_t*>(desc->fKey.begin() +
+                                                                   kEffectKeyLengthsOffset +
+                                                                   offsetIndex * sizeof(uint32_t));
+            *offsetLocation = offset;
+            ++offsetIndex;
+            GrEffectKeyBuilder b(&desc->fKey);
+            effectKeySuccess |= get_key_and_update_stats(drawState.getCoverageStage(s),
+                                                         gpu->glCaps(), requiresLocalCoordAttrib,
+                                                         &b, &readsDst, &readFragPosition,
+                                                         &hasVertexCode);
+            offset += b.size();
         }
     }
+    if (!effectKeySuccess) {
+        desc->fKey.reset();
+        return false;
+    }
+
+    KeyHeader* header = desc->header();
+    // make sure any padding in the header is zeroed.
+    memset(desc->header(), 0, kHeaderSize);
+
+    // Because header is a pointer into the dynamic array, we can't push any new data into the key
+    // below here.
 
     header->fHasVertexCode = hasVertexCode || requiresLocalCoordAttrib;
     header->fEmitsPointSize = GrGpu::kDrawPoints_DrawType == drawType;
@@ -268,18 +290,23 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
     header->fColorEffectCnt = colorStages->count();
     header->fCoverageEffectCnt = coverageStages->count();
 
-    *desc->checksum() = 0;
-    *desc->checksum() = SkChecksum::Compute(reinterpret_cast<uint32_t*>(desc->fKey.get()),
-                                            newKeyLength);
-    desc->fInitialized = true;
+    desc->finalize();
+    return true;
+}
+
+void GrGLProgramDesc::finalize() {
+    int keyLength = fKey.count();
+    SkASSERT(0 == (keyLength % 4));
+    *this->atOffset<uint32_t, kLengthOffset>() = SkToU32(keyLength);
+
+    uint32_t* checksum = this->atOffset<uint32_t, kChecksumOffset>();
+    *checksum = 0;
+    *checksum = SkChecksum::Compute(reinterpret_cast<uint32_t*>(fKey.begin()), keyLength);
 }
 
 GrGLProgramDesc& GrGLProgramDesc::operator= (const GrGLProgramDesc& other) {
-    fInitialized = other.fInitialized;
-    if (fInitialized) {
-        size_t keyLength = other.keyLength();
-        fKey.reset(keyLength);
-        memcpy(fKey.get(), other.fKey.get(), keyLength);
-    }
+    size_t keyLength = other.keyLength();
+    fKey.reset(keyLength);
+    memcpy(fKey.begin(), other.fKey.begin(), keyLength);
     return *this;
 }
diff --git a/src/gpu/gl/GrGLProgramDesc.h b/src/gpu/gl/GrGLProgramDesc.h
index 9165f4eb8b..d7652f473c 100644
--- a/src/gpu/gl/GrGLProgramDesc.h
+++ b/src/gpu/gl/GrGLProgramDesc.h
@@ -10,7 +10,6 @@
 
 #include "GrGLEffect.h"
 #include "GrDrawState.h"
-#include "GrGLShaderBuilder.h"
 #include "GrGpu.h"
 
 class GrGpuGL;
@@ -30,13 +29,12 @@ class GrGpuGL;
     to be API-neutral then so could this class. */
 class GrGLProgramDesc {
 public:
-    GrGLProgramDesc() : fInitialized(false) {}
+    GrGLProgramDesc() {}
     GrGLProgramDesc(const GrGLProgramDesc& desc) { *this = desc; }
 
     // Returns this as a uint32_t array to be used as a key in the program cache.
     const uint32_t* asKey() const {
-        SkASSERT(fInitialized);
-        return reinterpret_cast<const uint32_t*>(fKey.get());
+        return reinterpret_cast<const uint32_t*>(fKey.begin());
     }
 
     // Gets the number of bytes in asKey(). It will be a 4-byte aligned value. When comparing two
@@ -48,7 +46,7 @@ public:
     uint32_t getChecksum() const { return *this->atOffset<uint32_t, kChecksumOffset>(); }
 
     // For unit testing.
-    void setRandom(SkRandom*,
+    bool setRandom(SkRandom*,
                    const GrGpuGL* gpu,
                    const GrRenderTarget* dummyDstRenderTarget,
                    const GrTexture* dummyDstCopyTexture,
@@ -64,7 +62,7 @@ public:
      * not contain all stages from the draw state and coverage stages from the drawState may
      * be treated as color stages in the output.
      */
-    static void Build(const GrDrawState&,
+    static bool Build(const GrDrawState&,
                       GrGpu::DrawType drawType,
                       GrDrawState::BlendOptFlags,
                       GrBlendCoeff srcCoeff,
@@ -76,12 +74,10 @@ public:
                       GrGLProgramDesc* outDesc);
 
     int numColorEffects() const {
-        SkASSERT(fInitialized);
         return this->getHeader().fColorEffectCnt;
     }
 
     int numCoverageEffects() const {
-        SkASSERT(fInitialized);
         return this->getHeader().fCoverageEffectCnt;
     }
 
@@ -90,7 +86,6 @@ public:
     GrGLProgramDesc& operator= (const GrGLProgramDesc& other);
 
     bool operator== (const GrGLProgramDesc& other) const {
-        SkASSERT(fInitialized && other.fInitialized);
         // The length is masked as a hint to the compiler that the address will be 4 byte aligned.
         return 0 == memcmp(this->asKey(), other.asKey(), this->keyLength() & ~0x3);
     }
@@ -145,13 +140,12 @@ private:
     }
 
     struct KeyHeader {
-        GrGLShaderBuilder::DstReadKey fDstReadKey;      // set by GrGLShaderBuilder if there
+        uint8_t                     fDstReadKey;        // set by GrGLShaderBuilder if there
                                                         // are effects that must read the dst.
                                                         // Otherwise, 0.
-        GrGLShaderBuilder::FragPosKey fFragPosKey;      // set by GrGLShaderBuilder if there are
+        uint8_t                     fFragPosKey;        // set by GrGLShaderBuilder if there are
                                                         // effects that read the fragment position.
                                                         // Otherwise, 0.
-
         ColorInput                  fColorInput : 8;
         ColorInput                  fCoverageInput : 8;
         CoverageOutput              fCoverageOutput : 8;
@@ -174,48 +168,72 @@ private:
         int8_t                      fCoverageEffectCnt;
     };
 
-    // The key is 1 uint32_t for the length, followed another for the checksum, the header, and then
-    // the effect keys. Everything is fixed length except the effect key array.
+    // The key, stored in fKey, is composed of five parts:
+    // 1. uint32_t for total key length.
+    // 2. uint32_t for a checksum.
+    // 3. Header struct defined above.
+    // 4. uint32_t offsets to beginning of every effects' key (see 5).
+    // 5. per-effect keys. Each effect's key is a variable length array of uint32_t.
     enum {
         kLengthOffset = 0,
         kChecksumOffset = kLengthOffset + sizeof(uint32_t),
         kHeaderOffset = kChecksumOffset + sizeof(uint32_t),
         kHeaderSize = SkAlign4(sizeof(KeyHeader)),
-        kEffectKeyOffset = kHeaderOffset + kHeaderSize,
+        kEffectKeyLengthsOffset = kHeaderOffset + kHeaderSize,
     };
 
     template<typename T, size_t OFFSET> T* atOffset() {
-        return reinterpret_cast<T*>(reinterpret_cast<intptr_t>(fKey.get()) + OFFSET);
+        return reinterpret_cast<T*>(reinterpret_cast<intptr_t>(fKey.begin()) + OFFSET);
     }
 
     template<typename T, size_t OFFSET> const T* atOffset() const {
-        return reinterpret_cast<const T*>(reinterpret_cast<intptr_t>(fKey.get()) + OFFSET);
+        return reinterpret_cast<const T*>(reinterpret_cast<intptr_t>(fKey.begin()) + OFFSET);
     }
 
-    typedef GrGLEffect::EffectKey EffectKey;
+    typedef GrBackendEffectFactory::EffectKey EffectKey;
 
-    uint32_t* checksum() { return this->atOffset<uint32_t, kChecksumOffset>(); }
     KeyHeader* header() { return this->atOffset<KeyHeader, kHeaderOffset>(); }
-    EffectKey* effectKeys() { return this->atOffset<EffectKey, kEffectKeyOffset>(); }
+
+    void finalize();
 
     const KeyHeader& getHeader() const { return *this->atOffset<KeyHeader, kHeaderOffset>(); }
-    const EffectKey* getEffectKeys() const { return this->atOffset<EffectKey, kEffectKeyOffset>(); }
 
-    static size_t KeyLength(int effectCnt) {
-        GR_STATIC_ASSERT(!(sizeof(EffectKey) & 0x3));
-        return kEffectKeyOffset + effectCnt * sizeof(EffectKey);
-    }
+    /** Used to provide effects' keys to their emitCode() function. */
+    class EffectKeyProvider {
+    public:
+        enum EffectType {
+            kColor_EffectType,
+            kCoverage_EffectType,
+        };
+
+        EffectKeyProvider(const GrGLProgramDesc* desc, EffectType type) : fDesc(desc) {
+            // Coverage effect key offsets begin immediately after those of the color effects.
+            fBaseIndex = kColor_EffectType == type ? 0 : desc->numColorEffects();
+        }
+
+        EffectKey get(int index) const {
+            const uint32_t* offsets = reinterpret_cast<const uint32_t*>(fDesc->fKey.begin() +
+                                                                        kEffectKeyLengthsOffset);
+            uint32_t offset = offsets[fBaseIndex + index];
+            return *reinterpret_cast<const EffectKey*>(fDesc->fKey.begin() + offset);
+        }
+    private:
+        const GrGLProgramDesc*  fDesc;
+        int                     fBaseIndex;
+    };
 
     enum {
-        kMaxPreallocEffects = 16,
-        kPreAllocSize = kEffectKeyOffset +  kMaxPreallocEffects * sizeof(EffectKey),
+        kMaxPreallocEffects = 8,
+        kIntsPerEffect      = 4,    // This is an overestimate of the average effect key size.
+        kPreAllocSize = kEffectKeyLengthsOffset +
+                        kMaxPreallocEffects * sizeof(uint32_t) * kIntsPerEffect,
     };
 
-    SkAutoSMalloc<kPreAllocSize> fKey;
-    bool fInitialized;
+    SkSTArray<kPreAllocSize, uint8_t, true> fKey;
 
-    // GrGLProgram and GrGLShaderBuilder read the private fields to generate code. TODO: Move all
-    // code generation to GrGLShaderBuilder (and maybe add getters rather than friending).
+    // GrGLProgram and GrGLShaderBuilder read the private fields to generate code. TODO: Split out
+    // part of GrGLShaderBuilder that is used by effects so that this header doesn't need to be
+    // visible to GrGLEffects. Then make public accessors as necessary and remove friends.
     friend class GrGLProgram;
     friend class GrGLShaderBuilder;
     friend class GrGLFullShaderBuilder;
diff --git a/src/gpu/gl/GrGLProgramEffects.cpp b/src/gpu/gl/GrGLProgramEffects.cpp
index fd91f584c4..65d14fde11 100644
--- a/src/gpu/gl/GrGLProgramEffects.cpp
+++ b/src/gpu/gl/GrGLProgramEffects.cpp
@@ -239,7 +239,7 @@ void GrGLVertexProgramEffects::emitEffect(GrGLFullShaderBuilder* builder,
     SkSTArray<4, TextureSampler> samplers(effect->numTextures());
 
     this->emitAttributes(builder, stage);
-    this->emitTransforms(builder, effect, key, &coords);
+    this->emitTransforms(builder, drawEffect, &coords);
     this->emitSamplers(builder, effect, &samplers);
 
     GrGLEffect* glEffect = effect->getFactory().createGLInstance(drawEffect);
@@ -277,12 +277,11 @@ void GrGLVertexProgramEffects::emitAttributes(GrGLFullShaderBuilder* builder,
 }
 
 void GrGLVertexProgramEffects::emitTransforms(GrGLFullShaderBuilder* builder,
-                                              const GrEffect* effect,
-                                              EffectKey effectKey,
+                                              const GrDrawEffect& drawEffect,
                                               TransformedCoordsArray* outCoords) {
     SkTArray<Transform, true>& transforms = fTransforms.push_back();
-    EffectKey totalKey = GrBackendEffectFactory::GetTransformKey(effectKey);
-    int numTransforms = effect->numTransforms();
+    EffectKey totalKey = GenTransformKey(drawEffect);
+    int numTransforms = drawEffect.effect()->numTransforms();
     transforms.push_back_n(numTransforms);
     for (int t = 0; t < numTransforms; t++) {
         GrSLType varyingType = kVoid_GrSLType;
@@ -398,7 +397,7 @@ void GrGLPathTexGenProgramEffects::emitEffect(GrGLFragmentOnlyShaderBuilder* bui
     SkSTArray<4, TextureSampler> samplers(effect->numTextures());
 
     SkASSERT(0 == stage.getVertexAttribIndexCount());
-    this->setupPathTexGen(builder, effect, key, &coords);
+    this->setupPathTexGen(builder, drawEffect, &coords);
     this->emitSamplers(builder, effect, &samplers);
 
     GrGLEffect* glEffect = effect->getFactory().createGLInstance(drawEffect);
@@ -416,11 +415,10 @@ void GrGLPathTexGenProgramEffects::emitEffect(GrGLFragmentOnlyShaderBuilder* bui
 }
 
 void GrGLPathTexGenProgramEffects::setupPathTexGen(GrGLFragmentOnlyShaderBuilder* builder,
-                                           const GrEffect* effect,
-                                           EffectKey effectKey,
+                                           const GrDrawEffect& drawEffect,
                                            TransformedCoordsArray* outCoords) {
-    int numTransforms = effect->numTransforms();
-    EffectKey totalKey = GrBackendEffectFactory::GetTransformKey(effectKey);
+    int numTransforms = drawEffect.effect()->numTransforms();
+    EffectKey totalKey = GenTransformKey(drawEffect);
     int texCoordIndex = builder->addTexCoordSets(numTransforms);
     SkNEW_APPEND_TO_TARRAY(&fTransforms, Transforms, (totalKey, texCoordIndex));
     SkString name;
diff --git a/src/gpu/gl/GrGLProgramEffects.h b/src/gpu/gl/GrGLProgramEffects.h
index 137befd6ee..5a2fefd7d4 100644
--- a/src/gpu/gl/GrGLProgramEffects.h
+++ b/src/gpu/gl/GrGLProgramEffects.h
@@ -189,8 +189,7 @@ private:
      * TransformedCoordsArray* object, which is in turn passed to the effect's emitCode() function.
      */
     void emitTransforms(GrGLFullShaderBuilder*,
-                        const GrEffect*,
-                        EffectKey,
+                        const GrDrawEffect&,
                         TransformedCoordsArray*);
 
     /**
@@ -277,8 +276,7 @@ private:
      * effect's emitCode() function.
      */
     void setupPathTexGen(GrGLFragmentOnlyShaderBuilder*,
-                         const GrEffect*,
-                         EffectKey,
+                         const GrDrawEffect&,
                          TransformedCoordsArray*);
 
     /**
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 4b7de02793..7a57d8e32e 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -194,15 +194,19 @@ bool GrGLShaderBuilder::genProgram(const GrEffectStage* colorStages[],
     ///////////////////////////////////////////////////////////////////////////
     // emit the per-effect code for both color and coverage effects
 
+    GrGLProgramDesc::EffectKeyProvider colorKeyProvider(
+        &this->desc(), GrGLProgramDesc::EffectKeyProvider::kColor_EffectType);
     fOutput.fColorEffects.reset(this->createAndEmitEffects(colorStages,
-                                                           this->desc().getEffectKeys(),
                                                            this->desc().numColorEffects(),
+                                                           colorKeyProvider,
                                                            &inputColor));
 
+    GrGLProgramDesc::EffectKeyProvider coverageKeyProvider(
+        &this->desc(), GrGLProgramDesc::EffectKeyProvider::kCoverage_EffectType);
     fOutput.fCoverageEffects.reset(this->createAndEmitEffects(coverageStages,
-                                    this->desc().getEffectKeys() + this->desc().numColorEffects(),
-                                    this->desc().numCoverageEffects(),
-                                    &inputCoverage));
+                                   this->desc().numCoverageEffects(),
+                                   coverageKeyProvider,
+                                   &inputCoverage));
 
     this->emitCodeAfterEffects();
 
@@ -601,8 +605,8 @@ void GrGLShaderBuilder::appendUniformDecls(ShaderVisibility visibility,
 
 void GrGLShaderBuilder::createAndEmitEffects(GrGLProgramEffectsBuilder* programEffectsBuilder,
                                              const GrEffectStage* effectStages[],
-                                             const EffectKey effectKeys[],
                                              int effectCnt,
+                                             const GrGLProgramDesc::EffectKeyProvider& keyProvider,
                                              GrGLSLExpr4* fsInOutColor) {
     bool effectEmitted = false;
 
@@ -632,7 +636,7 @@ void GrGLShaderBuilder::createAndEmitEffects(GrGLProgramEffectsBuilder* programE
 
 
         programEffectsBuilder->emitEffect(stage,
-                                          effectKeys[e],
+                                          keyProvider.get(e),
                                           outColor.c_str(),
                                           inColor.isOnes() ? NULL : inColor.c_str(),
                                           fCodeStage.stageIndex());
@@ -976,15 +980,15 @@ const SkString* GrGLFullShaderBuilder::getEffectAttributeName(int attributeIndex
 
 GrGLProgramEffects* GrGLFullShaderBuilder::createAndEmitEffects(
         const GrEffectStage* effectStages[],
-        const EffectKey effectKeys[],
         int effectCnt,
+        const GrGLProgramDesc::EffectKeyProvider& keyProvider,
         GrGLSLExpr4* inOutFSColor) {
 
     GrGLVertexProgramEffectsBuilder programEffectsBuilder(this, effectCnt);
     this->INHERITED::createAndEmitEffects(&programEffectsBuilder,
                                           effectStages,
-                                          effectKeys,
                                           effectCnt,
+                                          keyProvider,
                                           inOutFSColor);
     return programEffectsBuilder.finish();
 }
@@ -1093,16 +1097,16 @@ int GrGLFragmentOnlyShaderBuilder::addTexCoordSets(int count) {
 
 GrGLProgramEffects* GrGLFragmentOnlyShaderBuilder::createAndEmitEffects(
         const GrEffectStage* effectStages[],
-        const EffectKey effectKeys[],
         int effectCnt,
+        const GrGLProgramDesc::EffectKeyProvider& keyProvider,
         GrGLSLExpr4* inOutFSColor) {
 
     GrGLPathTexGenProgramEffectsBuilder pathTexGenEffectsBuilder(this,
                                                                  effectCnt);
     this->INHERITED::createAndEmitEffects(&pathTexGenEffectsBuilder,
                                           effectStages,
-                                          effectKeys,
                                           effectCnt,
+                                          keyProvider,
                                           inOutFSColor);
     return pathTexGenEffectsBuilder.finish();
 }
diff --git a/src/gpu/gl/GrGLShaderBuilder.h b/src/gpu/gl/GrGLShaderBuilder.h
index 7e71acf901..c28cd0999b 100644
--- a/src/gpu/gl/GrGLShaderBuilder.h
+++ b/src/gpu/gl/GrGLShaderBuilder.h
@@ -13,6 +13,7 @@
 #include "GrColor.h"
 #include "GrEffect.h"
 #include "SkTypes.h"
+#include "gl/GrGLProgramDesc.h"
 #include "gl/GrGLProgramEffects.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLUniformManager.h"
@@ -253,8 +254,8 @@ protected:
     // Helper for emitEffects().
     void createAndEmitEffects(GrGLProgramEffectsBuilder*,
                               const GrEffectStage* effectStages[],
-                              const EffectKey effectKeys[],
                               int effectCnt,
+                              const GrGLProgramDesc::EffectKeyProvider&,
                               GrGLSLExpr4* inOutFSColor);
 
     // Generates a name for a variable. The generated string will be name prefixed by the prefix
@@ -338,15 +339,15 @@ private:
 
     /**
     * Adds code for effects and returns a GrGLProgramEffects* object. The caller is responsible for
-    * deleting it when finished. effectStages contains the effects to add. effectKeys[i] is the key
-    * generated from effectStages[i]. inOutFSColor specifies the input color to the first stage and
-    * is updated to be the output color of the last stage.
-    * The handles to texture samplers for effectStage[i] are added to
+    * deleting it when finished. effectStages contains the effects to add. The effect key provider 
+    * is used to communicate the key each effect created in its GenKey function. inOutFSColor
+    * specifies the input color to the first stage and is updated to be the output color of the
+    * last stage. The handles to texture samplers for effectStage[i] are added to
     * effectSamplerHandles[i].
     */
     virtual GrGLProgramEffects* createAndEmitEffects(const GrEffectStage* effectStages[],
-                                                     const EffectKey effectKeys[],
                                                      int effectCnt,
+                                                     const GrGLProgramDesc::EffectKeyProvider&,
                                                      GrGLSLExpr4* inOutFSColor) = 0;
 
     /**
@@ -465,8 +466,8 @@ private:
     virtual void emitCodeBeforeEffects(GrGLSLExpr4* color, GrGLSLExpr4* coverage) SK_OVERRIDE;
 
     virtual GrGLProgramEffects* createAndEmitEffects(const GrEffectStage* effectStages[],
-                                                     const EffectKey effectKeys[],
                                                      int effectCnt,
+                                                     const GrGLProgramDesc::EffectKeyProvider&,
                                                      GrGLSLExpr4* inOutFSColor) SK_OVERRIDE;
 
     virtual void emitCodeAfterEffects() SK_OVERRIDE;
@@ -510,8 +511,8 @@ private:
     virtual void emitCodeBeforeEffects(GrGLSLExpr4* color, GrGLSLExpr4* coverage) SK_OVERRIDE {}
 
     virtual GrGLProgramEffects* createAndEmitEffects(const GrEffectStage* effectStages[],
-                                                     const EffectKey effectKeys[],
                                                      int effectCnt,
+                                                     const GrGLProgramDesc::EffectKeyProvider&,
                                                      GrGLSLExpr4* inOutFSColor) SK_OVERRIDE;
 
     virtual void emitCodeAfterEffects() SK_OVERRIDE {}
diff --git a/src/gpu/gl/GrGpuGL_program.cpp b/src/gpu/gl/GrGpuGL_program.cpp
index bd4758c856..9e1b6f5c2b 100644
--- a/src/gpu/gl/GrGpuGL_program.cpp
+++ b/src/gpu/gl/GrGpuGL_program.cpp
@@ -234,7 +234,7 @@ bool GrGpuGL::flushGraphicsState(DrawType type, const GrDeviceCoordTexture* dstC
         SkSTArray<8, const GrEffectStage*, true> colorStages;
         SkSTArray<8, const GrEffectStage*, true> coverageStages;
         GrGLProgramDesc desc;
-        GrGLProgramDesc::Build(this->getDrawState(),
+        if (!GrGLProgramDesc::Build(this->getDrawState(),
                                type,
                                blendOpts,
                                srcCoeff,
@@ -243,7 +243,10 @@ bool GrGpuGL::flushGraphicsState(DrawType type, const GrDeviceCoordTexture* dstC
                                dstCopy,
                                &colorStages,
                                &coverageStages,
-                               &desc);
+                               &desc)) {
+            SkDEBUGFAIL("Failed to generate GL program descriptor");
+            return false;
+        }
 
         fCurrentProgram.reset(fProgramCache->getProgram(desc,
                                                         colorStages.begin(),