1 files changed, 161 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.cpp b/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.cpp
new file mode 100644
index 0000000000..34b43365cf
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.cpp
@@ -0,0 +1,161 @@
+//
+// Copyright 2002 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/BuiltInFunctionEmulator.h"
+#include "angle_gl.h"
+#include "compiler/translator/Symbol.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+
+namespace sh
+{
+
+class BuiltInFunctionEmulator::BuiltInFunctionEmulationMarker : public TIntermTraverser
+{
+  public:
+    BuiltInFunctionEmulationMarker(BuiltInFunctionEmulator &emulator)
+        : TIntermTraverser(true, false, false), mEmulator(emulator)
+    {}
+
+    bool visitUnary(Visit visit, TIntermUnary *node) override
+    {
+        if (node->getFunction())
+        {
+            bool needToEmulate = mEmulator.setFunctionCalled(node->getFunction());
+            if (needToEmulate)
+                node->setUseEmulatedFunction();
+        }
+        return true;
+    }
+
+    bool visitAggregate(Visit visit, TIntermAggregate *node) override
+    {
+        // Here we handle all the math built-in functions, not just the ones that are currently
+        // identified as problematic.
+        if (!BuiltInGroup::IsMath(node->getOp()))
+        {
+            return true;
+        }
+        bool needToEmulate = mEmulator.setFunctionCalled(node->getFunction());
+        if (needToEmulate)
+            node->setUseEmulatedFunction();
+        return true;
+    }
+
+  private:
+    BuiltInFunctionEmulator &mEmulator;
+};
+
+BuiltInFunctionEmulator::BuiltInFunctionEmulator() {}
+
+void BuiltInFunctionEmulator::addEmulatedFunction(const TSymbolUniqueId &uniqueId,
+                                                  const char *emulatedFunctionDefinition)
+{
+    mEmulatedFunctions[uniqueId.get()] = std::string(emulatedFunctionDefinition);
+}
+
+void BuiltInFunctionEmulator::addEmulatedFunctionWithDependency(
+    const TSymbolUniqueId &dependency,
+    const TSymbolUniqueId &uniqueId,
+    const char *emulatedFunctionDefinition)
+{
+    mEmulatedFunctions[uniqueId.get()]    = std::string(emulatedFunctionDefinition);
+    mFunctionDependencies[uniqueId.get()] = dependency.get();
+}
+
+bool BuiltInFunctionEmulator::isOutputEmpty() const
+{
+    return (mFunctions.size() == 0);
+}
+
+void BuiltInFunctionEmulator::outputEmulatedFunctions(TInfoSinkBase &out) const
+{
+    for (const auto &function : mFunctions)
+    {
+        const char *body = findEmulatedFunction(function);
+        ASSERT(body);
+        out << body;
+        out << "\n\n";
+    }
+}
+
+const char *BuiltInFunctionEmulator::findEmulatedFunction(int uniqueId) const
+{
+    for (const auto &queryFunction : mQueryFunctions)
+    {
+        const char *result = queryFunction(uniqueId);
+        if (result)
+        {
+            return result;
+        }
+    }
+
+    const auto &result = mEmulatedFunctions.find(uniqueId);
+    if (result != mEmulatedFunctions.end())
+    {
+        return result->second.c_str();
+    }
+
+    return nullptr;
+}
+
+bool BuiltInFunctionEmulator::setFunctionCalled(const TFunction *function)
+{
+    ASSERT(function != nullptr);
+    return setFunctionCalled(function->uniqueId().get());
+}
+
+bool BuiltInFunctionEmulator::setFunctionCalled(int uniqueId)
+{
+    if (!findEmulatedFunction(uniqueId))
+    {
+        return false;
+    }
+
+    for (size_t i = 0; i < mFunctions.size(); ++i)
+    {
+        if (mFunctions[i] == uniqueId)
+            return true;
+    }
+    // If the function depends on another, mark the dependency as called.
+    auto dependency = mFunctionDependencies.find(uniqueId);
+    if (dependency != mFunctionDependencies.end())
+    {
+        setFunctionCalled((*dependency).second);
+    }
+    mFunctions.push_back(uniqueId);
+    return true;
+}
+
+void BuiltInFunctionEmulator::markBuiltInFunctionsForEmulation(TIntermNode *root)
+{
+    ASSERT(root);
+
+    if (mEmulatedFunctions.empty() && mQueryFunctions.empty())
+        return;
+
+    BuiltInFunctionEmulationMarker marker(*this);
+    root->traverse(&marker);
+}
+
+void BuiltInFunctionEmulator::cleanup()
+{
+    mFunctions.clear();
+    mFunctionDependencies.clear();
+}
+
+void BuiltInFunctionEmulator::addFunctionMap(BuiltinQueryFunc queryFunc)
+{
+    mQueryFunctions.push_back(queryFunc);
+}
+
+// static
+void BuiltInFunctionEmulator::WriteEmulatedFunctionName(TInfoSinkBase &out, const char *name)
+{
+    ASSERT(name[strlen(name) - 1] != '(');
+    out << name << "_emu";
+}
+
+}  // namespace sh