Speculative "fix" for crash in analyzeProcessors

From the bug it looks like a null fragment processors may be getting into the processor set. This CL tries to plug any gaps in our fragmentProcessor handling.

The only real substantive part to this CL is the addition of some "if (!fp) { return nullptr; }" blocks.

Everything else is just to add chokepoints for processor allocation.

Bug: 734076
Change-Id: I4952b1a05bc6690d5aa09de977fa6dc54c80338a
Reviewed-on: https://skia-review.googlesource.com/21267
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

1 files changed, 23 insertions, 19 deletions

diff --git a/src/shaders/SkLightingShader.cpp b/src/shaders/SkLightingShader.cpp
index cdfa528e1e..b19f9df97f 100644
--- a/src/shaders/SkLightingShader.cpp
+++ b/src/shaders/SkLightingShader.cpp
@@ -114,21 +114,9 @@ private:
 // premul'd.
 class LightingFP : public GrFragmentProcessor {
 public:
-    LightingFP(sk_sp<GrFragmentProcessor> normalFP, sk_sp<SkLights> lights)
-            : INHERITED(kPreservesOpaqueInput_OptimizationFlag) {
-        // fuse all ambient lights into a single one
-        fAmbientColor = lights->ambientLightColor();
-        for (int i = 0; i < lights->numLights(); ++i) {
-            if (SkLights::Light::kDirectional_LightType == lights->light(i).type()) {
-                fDirectionalLights.push_back(lights->light(i));
-                // TODO get the handle to the shadow map if there is one
-            } else {
-                SkDEBUGFAIL("Unimplemented Light Type passed to LightingFP");
-            }
-        }
-
-        this->registerChildProcessor(std::move(normalFP));
-        this->initClassID<LightingFP>();
+    static sk_sp<GrFragmentProcessor> Make(sk_sp<GrFragmentProcessor> normalFP,
+                                           sk_sp<SkLights> lights) {
+        return sk_sp<GrFragmentProcessor>(new LightingFP(std::move(normalFP), std::move(lights)));
     }
 
     class GLSLLightingFP : public GrGLSLFragmentProcessor {
@@ -247,6 +235,23 @@ public:
     const SkColor3f& ambientColor() const { return fAmbientColor; }
 
 private:
+    LightingFP(sk_sp<GrFragmentProcessor> normalFP, sk_sp<SkLights> lights)
+            : INHERITED(kPreservesOpaqueInput_OptimizationFlag) {
+        // fuse all ambient lights into a single one
+        fAmbientColor = lights->ambientLightColor();
+        for (int i = 0; i < lights->numLights(); ++i) {
+            if (SkLights::Light::kDirectional_LightType == lights->light(i).type()) {
+                fDirectionalLights.push_back(lights->light(i));
+                // TODO get the handle to the shadow map if there is one
+            } else {
+                SkDEBUGFAIL("Unimplemented Light Type passed to LightingFP");
+            }
+        }
+
+        this->registerChildProcessor(std::move(normalFP));
+        this->initClassID<LightingFP>();
+    }
+
     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new GLSLLightingFP; }
 
     bool onIsEqual(const GrFragmentProcessor& proc) const override {
@@ -272,9 +277,9 @@ sk_sp<GrFragmentProcessor> SkLightingShaderImpl::asFragmentProcessor(const AsFPA
     if (fDiffuseShader) {
         sk_sp<GrFragmentProcessor> fpPipeline[] = {
             as_SB(fDiffuseShader)->asFragmentProcessor(args),
-            sk_make_sp<LightingFP>(std::move(normalFP), fLights)
+            LightingFP::Make(std::move(normalFP), fLights)
         };
-        if(!fpPipeline[0]) {
+        if (!fpPipeline[0] || !fpPipeline[1]) {
             return nullptr;
         }
 
@@ -284,8 +289,7 @@ sk_sp<GrFragmentProcessor> SkLightingShaderImpl::asFragmentProcessor(const AsFPA
     } else {
         // FP is wrapped because paint comes in unpremul'd to fragment shader, but LightingFP
         // expects premul'd color.
-        return GrFragmentProcessor::PremulInput(sk_make_sp<LightingFP>(std::move(normalFP),
-                                                                       fLights));
+        return GrFragmentProcessor::PremulInput(LightingFP::Make(std::move(normalFP), fLights));
     }
 }