1 files changed, 80 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.h b/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.h
new file mode 100644
index 0000000000..7ebd6bc087
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/BuiltInFunctionEmulator.h
@@ -0,0 +1,80 @@
+//
+// Copyright 2011 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.
+//
+
+#ifndef COMPILER_TRANSLATOR_BUILTINFUNCTIONEMULATOR_H_
+#define COMPILER_TRANSLATOR_BUILTINFUNCTIONEMULATOR_H_
+
+#include "compiler/translator/InfoSink.h"
+
+namespace sh
+{
+
+class TIntermNode;
+class TFunction;
+class TSymbolUniqueId;
+
+using BuiltinQueryFunc = const char *(int);
+
+//
+// This class decides which built-in functions need to be replaced with the emulated ones. It can be
+// used to work around driver bugs or implement functions that are not natively implemented on a
+// specific platform.
+//
+class BuiltInFunctionEmulator
+{
+  public:
+    BuiltInFunctionEmulator();
+
+    void markBuiltInFunctionsForEmulation(TIntermNode *root);
+
+    void cleanup();
+
+    // "name" gets written as "name_emu".
+    static void WriteEmulatedFunctionName(TInfoSinkBase &out, const char *name);
+
+    bool isOutputEmpty() const;
+
+    // Output function emulation definition. This should be before any other shader source.
+    void outputEmulatedFunctions(TInfoSinkBase &out) const;
+
+    // Add functions that need to be emulated.
+    void addEmulatedFunction(const TSymbolUniqueId &uniqueId,
+                             const char *emulatedFunctionDefinition);
+
+    void addEmulatedFunctionWithDependency(const TSymbolUniqueId &dependency,
+                                           const TSymbolUniqueId &uniqueId,
+                                           const char *emulatedFunctionDefinition);
+
+    void addFunctionMap(BuiltinQueryFunc queryFunc);
+
+  private:
+    class BuiltInFunctionEmulationMarker;
+
+    // Records that a function is called by the shader and might need to be emulated. If the
+    // function is not in mEmulatedFunctions, this becomes a no-op. Returns true if the function
+    // call needs to be replaced with an emulated one.
+    bool setFunctionCalled(const TFunction *function);
+    bool setFunctionCalled(int uniqueId);
+
+    const char *findEmulatedFunction(int uniqueId) const;
+
+    // Map from function unique id to emulated function definition
+    std::map<int, std::string> mEmulatedFunctions;
+
+    // Map from dependent functions to their dependencies. This structure allows each function to
+    // have at most one dependency.
+    std::map<int, int> mFunctionDependencies;
+
+    // Called function ids
+    std::vector<int> mFunctions;
+
+    // Constexpr function tables.
+    std::vector<BuiltinQueryFunc *> mQueryFunctions;
+};
+
+}  // namespace sh
+
+#endif  // COMPILER_TRANSLATOR_BUILTINFUNCTIONEMULATOR_H_