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/*
* 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 "include/core/SkTypes.h"
#include "include/private/SkSLIRNode.h"
#include "include/sksl/SkSLPosition.h"
#include "src/sksl/ir/SkSLExpression.h"
#include <cstdint>
#include <memory>
#include <string>
namespace SkSL {
class Variable;
enum class OperatorPrecedence : uint8_t;
enum class VariableRefKind : int8_t {
kRead,
kWrite,
kReadWrite,
// taking the address of a variable - we consider this a read & write but don't complain if
// the variable was not previously assigned
kPointer
};
/**
* 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.
*/
class VariableReference final : public Expression {
public:
using RefKind = VariableRefKind;
inline static constexpr Kind kIRNodeKind = Kind::kVariableReference;
VariableReference(Position pos, const Variable* variable, RefKind refKind);
// Creates a VariableReference. There isn't much in the way of error-checking or optimization
// opportunities here.
static std::unique_ptr<Expression> Make(Position pos,
const Variable* variable,
RefKind refKind = RefKind::kRead) {
SkASSERT(variable);
return std::make_unique<VariableReference>(pos, variable, refKind);
}
VariableReference(const VariableReference&) = delete;
VariableReference& operator=(const VariableReference&) = delete;
const Variable* variable() const {
return fVariable;
}
RefKind refKind() const {
return fRefKind;
}
void setRefKind(RefKind refKind);
void setVariable(const Variable* variable);
std::unique_ptr<Expression> clone(Position pos) const override {
return std::make_unique<VariableReference>(pos, this->variable(), this->refKind());
}
std::string description(OperatorPrecedence) const override;
private:
const Variable* fVariable;
VariableRefKind fRefKind;
using INHERITED = Expression;
};
} // namespace SkSL
#endif
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