1 files changed, 130 insertions, 0 deletions
diff --git a/gfx/angle/src/compiler/translator/timing/RestrictFragmentShaderTiming.cpp b/gfx/angle/src/compiler/translator/timing/RestrictFragmentShaderTiming.cpp
new file mode 100644
index 000000000..790974a2b
--- /dev/null
+++ b/gfx/angle/src/compiler/translator/timing/RestrictFragmentShaderTiming.cpp
@@ -0,0 +1,130 @@
+//
+// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "compiler/translator/InfoSink.h"
+#include "compiler/translator/ParseContext.h"
+#include "compiler/translator/depgraph/DependencyGraphOutput.h"
+#include "compiler/translator/timing/RestrictFragmentShaderTiming.h"
+
+RestrictFragmentShaderTiming::RestrictFragmentShaderTiming(TInfoSinkBase& sink)
+    : mSink(sink)
+    , mNumErrors(0)
+{
+    // Sampling ops found only in fragment shaders.
+    mSamplingOps.insert("texture2D(s21;vf2;f1;");
+    mSamplingOps.insert("texture2DProj(s21;vf3;f1;");
+    mSamplingOps.insert("texture2DProj(s21;vf4;f1;");
+    mSamplingOps.insert("textureCube(sC1;vf3;f1;");
+    // Sampling ops found in both vertex and fragment shaders.
+    mSamplingOps.insert("texture2D(s21;vf2;");
+    mSamplingOps.insert("texture2DProj(s21;vf3;");
+    mSamplingOps.insert("texture2DProj(s21;vf4;");
+    mSamplingOps.insert("textureCube(sC1;vf3;");
+    // Sampling ops provided by OES_EGL_image_external.
+    mSamplingOps.insert("texture2D(1;vf2;");
+    mSamplingOps.insert("texture2DProj(1;vf3;");
+    mSamplingOps.insert("texture2DProj(1;vf4;");
+    // Sampling ops provided by ARB_texture_rectangle.
+    mSamplingOps.insert("texture2DRect(1;vf2;");
+    mSamplingOps.insert("texture2DRectProj(1;vf3;");
+    mSamplingOps.insert("texture2DRectProj(1;vf4;");
+    // Sampling ops provided by EXT_shader_texture_lod.
+    mSamplingOps.insert("texture2DLodEXT(1;vf2;f1;");
+    mSamplingOps.insert("texture2DProjLodEXT(1;vf3;f1;");
+    mSamplingOps.insert("texture2DProjLodEXT(1;vf4;f1;");
+    mSamplingOps.insert("textureCubeLodEXT(1;vf4;f1;");
+    mSamplingOps.insert("texture2DGradEXT(1;vf2;vf2;vf2;");
+    mSamplingOps.insert("texture2DProjGradEXT(1;vf3;vf2;vf2;");
+    mSamplingOps.insert("texture2DProjGradEXT(1;vf4;vf2;vf2;");
+    mSamplingOps.insert("textureCubeGradEXT(1;vf3;vf3;vf3;");
+}
+
+// FIXME(mvujovic): We do not know if the execution time of built-in operations like sin, pow, etc.
+// can vary based on the value of the input arguments. If so, we should restrict those as well.
+void RestrictFragmentShaderTiming::enforceRestrictions(const TDependencyGraph& graph)
+{
+    mNumErrors = 0;
+
+    // FIXME(mvujovic): The dependency graph does not support user defined function calls right now,
+    // so we generate errors for them.
+    validateUserDefinedFunctionCallUsage(graph);
+
+    // Starting from each sampler, traverse the dependency graph and generate an error each time we
+    // hit a node where sampler dependent values are not allowed.
+    for (auto samplerSymbol : graph.samplerSymbols())
+    {
+        clearVisited();
+        samplerSymbol->traverse(this);
+    }
+}
+
+void RestrictFragmentShaderTiming::validateUserDefinedFunctionCallUsage(const TDependencyGraph& graph)
+{
+    for (const auto* functionCall : graph.userDefinedFunctionCalls())
+    {
+        beginError(functionCall->getIntermFunctionCall());
+        mSink << "A call to a user defined function is not permitted.\n";
+    }
+}
+
+void RestrictFragmentShaderTiming::beginError(const TIntermNode* node)
+{
+    ++mNumErrors;
+    mSink.prefix(EPrefixError);
+    mSink.location(node->getLine());
+}
+
+bool RestrictFragmentShaderTiming::isSamplingOp(const TIntermAggregate* intermFunctionCall) const
+{
+    return !intermFunctionCall->isUserDefined() &&
+           mSamplingOps.find(intermFunctionCall->getName()) != mSamplingOps.end();
+}
+
+void RestrictFragmentShaderTiming::visitArgument(TGraphArgument* parameter)
+{
+    // Texture cache access time might leak sensitive information.
+    // Thus, we restrict sampler dependent values from affecting the coordinate or LOD bias of a
+    // sampling operation.
+    if (isSamplingOp(parameter->getIntermFunctionCall())) {
+        switch (parameter->getArgumentNumber()) {
+            case 1:
+                // Second argument (coord)
+                beginError(parameter->getIntermFunctionCall());
+                mSink << "An expression dependent on a sampler is not permitted to be the"
+                      << " coordinate argument of a sampling operation.\n";
+                break;
+            case 2:
+                // Third argument (bias)
+                beginError(parameter->getIntermFunctionCall());
+                mSink << "An expression dependent on a sampler is not permitted to be the"
+                      << " bias argument of a sampling operation.\n";
+                break;
+            default:
+                // First argument (sampler)
+                break;
+        }
+    }
+}
+
+void RestrictFragmentShaderTiming::visitSelection(TGraphSelection* selection)
+{
+    beginError(selection->getIntermSelection());
+    mSink << "An expression dependent on a sampler is not permitted in a conditional statement.\n";
+}
+
+void RestrictFragmentShaderTiming::visitLoop(TGraphLoop* loop)
+{
+    beginError(loop->getIntermLoop());
+    mSink << "An expression dependent on a sampler is not permitted in a loop condition.\n";
+}
+
+void RestrictFragmentShaderTiming::visitLogicalOp(TGraphLogicalOp* logicalOp)
+{
+    beginError(logicalOp->getIntermLogicalOp());
+    mSink << "An expression dependent on a sampler is not permitted on the left hand side of a logical "
+          << logicalOp->getOpString()
+          << " operator.\n";
+}