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// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SRC_TINT_AST_VARIABLE_H_
#define SRC_TINT_AST_VARIABLE_H_
#include <utility>
#include <vector>
#include "src/tint/ast/access.h"
#include "src/tint/ast/attribute.h"
#include "src/tint/ast/expression.h"
#include "src/tint/ast/storage_class.h"
// Forward declarations
namespace tint::ast {
class BindingAttribute;
class GroupAttribute;
class LocationAttribute;
class Type;
} // namespace tint::ast
namespace tint::ast {
/// VariableBindingPoint holds a group and binding attribute.
struct VariableBindingPoint {
/// The `@group` part of the binding point
const GroupAttribute* group = nullptr;
/// The `@binding` part of the binding point
const BindingAttribute* binding = nullptr;
/// @returns true if the BindingPoint has a valid group and binding
/// attribute.
inline operator bool() const { return group && binding; }
};
/// Variable is the base class for Var, Let, Const, Override and Parameter.
///
/// An instance of this class represents one of five constructs in WGSL: "var" declaration, "let"
/// declaration, "override" declaration, "const" declaration, or formal parameter to a function.
///
/// @see https://www.w3.org/TR/WGSL/#value-decls
class Variable : public Castable<Variable, Node> {
public:
/// Constructor
/// @param program_id the identifier of the program that owns this node
/// @param source the variable source
/// @param sym the variable symbol
/// @param type the declared variable type
/// @param constructor the constructor expression
/// @param attributes the variable attributes
Variable(ProgramID program_id,
const Source& source,
const Symbol& sym,
const ast::Type* type,
const Expression* constructor,
AttributeList attributes);
/// Move constructor
Variable(Variable&&);
/// Destructor
~Variable() override;
/// @returns the binding point information from the variable's attributes.
/// @note binding points should only be applied to Var and Parameter types.
VariableBindingPoint BindingPoint() const;
/// @returns the kind of the variable, which can be used in diagnostics
/// e.g. "var", "let", "const", etc
virtual const char* Kind() const = 0;
/// The variable symbol
const Symbol symbol;
/// The declared variable type. This is null if the type is inferred, e.g.:
/// let f = 1.0;
/// var i = 1;
const ast::Type* const type;
/// The constructor expression or nullptr if none set
const Expression* const constructor;
/// The attributes attached to this variable
const AttributeList attributes;
};
/// A list of variables
using VariableList = std::vector<const Variable*>;
} // namespace tint::ast
#endif // SRC_TINT_AST_VARIABLE_H_