| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SKSL_VARIABLEREFERENCE |
| #define SKSL_VARIABLEREFERENCE |
| |
| #include "src/sksl/ir/SkSLExpression.h" |
| #include "src/sksl/ir/SkSLVariable.h" |
| |
| namespace SkSL { |
| |
| class IRGenerator; |
| |
| /** |
| * A reference to a variable, through which it can be read or written. In the statement: |
| * |
| * x = x + 1; |
| * |
| * there is only one Variable 'x', but two VariableReferences to it. |
| */ |
| struct VariableReference : public Expression { |
| static constexpr Kind kExpressionKind = kVariableReference_Kind; |
| |
| enum RefKind { |
| kRead_RefKind, |
| kWrite_RefKind, |
| kReadWrite_RefKind, |
| // taking the address of a variable - we consider this a read & write but don't complain if |
| // the variable was not previously assigned |
| kPointer_RefKind |
| }; |
| |
| VariableReference(int offset, const Variable& variable, RefKind refKind = kRead_RefKind); |
| |
| ~VariableReference() override; |
| |
| VariableReference(const VariableReference&) = delete; |
| VariableReference& operator=(const VariableReference&) = delete; |
| |
| RefKind refKind() const { |
| return fRefKind; |
| } |
| |
| void setRefKind(RefKind refKind); |
| |
| bool hasProperty(Property property) const override { |
| switch (property) { |
| case Property::kSideEffects: return false; |
| case Property::kContainsRTAdjust: return fVariable.fName == "sk_RTAdjust"; |
| default: |
| SkASSERT(false); |
| return false; |
| } |
| } |
| |
| bool isConstantOrUniform() const override { |
| return (fVariable.fModifiers.fFlags & Modifiers::kUniform_Flag) != 0; |
| } |
| |
| std::unique_ptr<Expression> clone() const override { |
| return std::unique_ptr<Expression>(new VariableReference(fOffset, fVariable, fRefKind)); |
| } |
| |
| String description() const override { |
| return fVariable.fName; |
| } |
| |
| static std::unique_ptr<Expression> copy_constant(const IRGenerator& irGenerator, |
| const Expression* expr); |
| |
| std::unique_ptr<Expression> constantPropagate(const IRGenerator& irGenerator, |
| const DefinitionMap& definitions) override; |
| |
| const Variable& fVariable; |
| RefKind fRefKind; |
| |
| private: |
| using INHERITED = Expression; |
| }; |
| |
| } // namespace SkSL |
| |
| #endif |