Files
swift-mirror/include/swift/AST/ASTVisitor.h
John McCall 0cd849b19c Complete the pattern-matching IR emission logic,
at least for exhaustive patterns.

Swift SVN r1359
2012-04-10 08:28:31 +00:00

115 lines
3.7 KiB
C++

//===-- ASTVisitor.h - Decl, Expr and Stmt Visitor --------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file defines the ASTVisitor class, and the DeclVisitor, ExprVisitor, and
// StmtVisitor template typedefs.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_AST_ASTVISITOR_H
#define SWIFT_AST_ASTVISITOR_H
#include "swift/AST/Decl.h"
#include "swift/AST/Expr.h"
#include "swift/AST/Pattern.h"
#include "swift/AST/Stmt.h"
#include "llvm/Support/ErrorHandling.h"
namespace swift {
/// ASTVisitor - This is a simple visitor class for Swift expressions.
template<typename ImplClass,
typename ExprRetTy = void,
typename StmtRetTy = void,
typename DeclRetTy = void,
typename PatternRetTy = void>
class ASTVisitor {
public:
DeclRetTy visit(Decl *D) {
switch (D->getKind()) {
#define DECL(CLASS, PARENT) \
case DeclKind::CLASS: \
return static_cast<ImplClass*>(this) \
->visit##CLASS##Decl(static_cast<CLASS##Decl*>(D));
#include "swift/AST/DeclNodes.def"
}
llvm_unreachable("Not reachable, all cases handled");
}
ExprRetTy visit(Expr *E) {
switch (E->getKind()) {
#define EXPR(CLASS, PARENT) \
case ExprKind::CLASS: \
return static_cast<ImplClass*>(this) \
->visit##CLASS##Expr(static_cast<CLASS##Expr*>(E));
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("Not reachable, all cases handled");
}
// Provide default implementations of abstract "visit" implementations that
// just chain to their base class. This allows visitors to just implement
// the base behavior and handle all subclasses if they desire. Since this is
// a template, it will only instantiate cases that are used and thus we still
// require full coverage of the AST nodes by the visitor.
#define ABSTRACT_EXPR(CLASS, PARENT) \
ExprRetTy visit##CLASS##Expr(CLASS##Expr *E) { \
return static_cast<ImplClass*>(this)->visit##PARENT(E); \
}
#define EXPR(CLASS, PARENT) ABSTRACT_EXPR(CLASS, PARENT)
#include "swift/AST/ExprNodes.def"
StmtRetTy visit(Stmt *S) {
switch (S->getKind()) {
#define STMT(CLASS, PARENT) \
case StmtKind::CLASS: \
return static_cast<ImplClass*>(this) \
->visit##CLASS##Stmt(static_cast<CLASS##Stmt*>(S));
#include "swift/AST/StmtNodes.def"
}
llvm_unreachable("Not reachable, all cases handled");
}
PatternRetTy visit(Pattern *P) {
switch (P->getKind()) {
#define PATTERN(CLASS, PARENT) \
case PatternKind::CLASS: \
return static_cast<ImplClass*>(this) \
->visit##CLASS##Pattern(static_cast<CLASS##Pattern*>(P));
#include "swift/AST/PatternNodes.def"
}
llvm_unreachable("Not reachable, all cases handled");
}
};
template<typename ImplClass, typename ExprRetTy = void>
using ExprVisitor = ASTVisitor<ImplClass, ExprRetTy>;
template<typename ImplClass, typename StmtRetTy = void>
using StmtVisitor = ASTVisitor<ImplClass, void, StmtRetTy>;
template<typename ImplClass, typename DeclRetTy = void>
using DeclVisitor = ASTVisitor<ImplClass, void, void, DeclRetTy>;
template<typename ImplClass, typename PatternRetTy = void>
using PatternVisitor = ASTVisitor<ImplClass, void, void, void, PatternRetTy>;
} // end namespace swift
#endif