StmtVisitor.h revision 360784 
1//===- StmtVisitor.h - Visitor for Stmt subclasses --------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file defines the StmtVisitor and ConstStmtVisitor interfaces.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_STMTVISITOR_H
14#define LLVM_CLANG_AST_STMTVISITOR_H
15
16#include "clang/AST/ExprConcepts.h"
17#include "clang/AST/ExprCXX.h"
18#include "clang/AST/ExprObjC.h"
19#include "clang/AST/ExprOpenMP.h"
20#include "clang/AST/Stmt.h"
21#include "clang/AST/StmtCXX.h"
22#include "clang/AST/StmtObjC.h"
23#include "clang/AST/StmtOpenMP.h"
24#include "clang/Basic/LLVM.h"
25#include "llvm/ADT/STLExtras.h"
26#include "llvm/Support/Casting.h"
27#include "llvm/Support/ErrorHandling.h"
28#include <utility>
29
30namespace clang {
31/// StmtVisitorBase - This class implements a simple visitor for Stmt
32/// subclasses. Since Expr derives from Stmt, this also includes support for
33/// visiting Exprs.
34template<template <typename> class Ptr, typename ImplClass, typename RetTy=void,
35         class... ParamTys>
36class StmtVisitorBase {
37public:
38#define PTR(CLASS) typename Ptr<CLASS>::type
39#define DISPATCH(NAME, CLASS) \
40  return static_cast<ImplClass*>(this)->Visit ## NAME( \
41    static_cast<PTR(CLASS)>(S), std::forward<ParamTys>(P)...)
42
43  RetTy Visit(PTR(Stmt) S, ParamTys... P) {
44    // If we have a binary expr, dispatch to the subcode of the binop.  A smart
45    // optimizer (e.g. LLVM) will fold this comparison into the switch stmt
46    // below.
47    if (PTR(BinaryOperator) BinOp = dyn_cast<BinaryOperator>(S)) {
48      switch (BinOp->getOpcode()) {
49      case BO_PtrMemD:   DISPATCH(BinPtrMemD,   BinaryOperator);
50      case BO_PtrMemI:   DISPATCH(BinPtrMemI,   BinaryOperator);
51      case BO_Mul:       DISPATCH(BinMul,       BinaryOperator);
52      case BO_Div:       DISPATCH(BinDiv,       BinaryOperator);
53      case BO_Rem:       DISPATCH(BinRem,       BinaryOperator);
54      case BO_Add:       DISPATCH(BinAdd,       BinaryOperator);
55      case BO_Sub:       DISPATCH(BinSub,       BinaryOperator);
56      case BO_Shl:       DISPATCH(BinShl,       BinaryOperator);
57      case BO_Shr:       DISPATCH(BinShr,       BinaryOperator);
58
59      case BO_LT:        DISPATCH(BinLT,        BinaryOperator);
60      case BO_GT:        DISPATCH(BinGT,        BinaryOperator);
61      case BO_LE:        DISPATCH(BinLE,        BinaryOperator);
62      case BO_GE:        DISPATCH(BinGE,        BinaryOperator);
63      case BO_EQ:        DISPATCH(BinEQ,        BinaryOperator);
64      case BO_NE:        DISPATCH(BinNE,        BinaryOperator);
65      case BO_Cmp:       DISPATCH(BinCmp,       BinaryOperator);
66
67      case BO_And:       DISPATCH(BinAnd,       BinaryOperator);
68      case BO_Xor:       DISPATCH(BinXor,       BinaryOperator);
69      case BO_Or :       DISPATCH(BinOr,        BinaryOperator);
70      case BO_LAnd:      DISPATCH(BinLAnd,      BinaryOperator);
71      case BO_LOr :      DISPATCH(BinLOr,       BinaryOperator);
72      case BO_Assign:    DISPATCH(BinAssign,    BinaryOperator);
73      case BO_MulAssign: DISPATCH(BinMulAssign, CompoundAssignOperator);
74      case BO_DivAssign: DISPATCH(BinDivAssign, CompoundAssignOperator);
75      case BO_RemAssign: DISPATCH(BinRemAssign, CompoundAssignOperator);
76      case BO_AddAssign: DISPATCH(BinAddAssign, CompoundAssignOperator);
77      case BO_SubAssign: DISPATCH(BinSubAssign, CompoundAssignOperator);
78      case BO_ShlAssign: DISPATCH(BinShlAssign, CompoundAssignOperator);
79      case BO_ShrAssign: DISPATCH(BinShrAssign, CompoundAssignOperator);
80      case BO_AndAssign: DISPATCH(BinAndAssign, CompoundAssignOperator);
81      case BO_OrAssign:  DISPATCH(BinOrAssign,  CompoundAssignOperator);
82      case BO_XorAssign: DISPATCH(BinXorAssign, CompoundAssignOperator);
83      case BO_Comma:     DISPATCH(BinComma,     BinaryOperator);
84      }
85    } else if (PTR(UnaryOperator) UnOp = dyn_cast<UnaryOperator>(S)) {
86      switch (UnOp->getOpcode()) {
87      case UO_PostInc:   DISPATCH(UnaryPostInc,   UnaryOperator);
88      case UO_PostDec:   DISPATCH(UnaryPostDec,   UnaryOperator);
89      case UO_PreInc:    DISPATCH(UnaryPreInc,    UnaryOperator);
90      case UO_PreDec:    DISPATCH(UnaryPreDec,    UnaryOperator);
91      case UO_AddrOf:    DISPATCH(UnaryAddrOf,    UnaryOperator);
92      case UO_Deref:     DISPATCH(UnaryDeref,     UnaryOperator);
93      case UO_Plus:      DISPATCH(UnaryPlus,      UnaryOperator);
94      case UO_Minus:     DISPATCH(UnaryMinus,     UnaryOperator);
95      case UO_Not:       DISPATCH(UnaryNot,       UnaryOperator);
96      case UO_LNot:      DISPATCH(UnaryLNot,      UnaryOperator);
97      case UO_Real:      DISPATCH(UnaryReal,      UnaryOperator);
98      case UO_Imag:      DISPATCH(UnaryImag,      UnaryOperator);
99      case UO_Extension: DISPATCH(UnaryExtension, UnaryOperator);
100      case UO_Coawait:   DISPATCH(UnaryCoawait,   UnaryOperator);
101      }
102    }
103
104    // Top switch stmt: dispatch to VisitFooStmt for each FooStmt.
105    switch (S->getStmtClass()) {
106    default: llvm_unreachable("Unknown stmt kind!");
107#define ABSTRACT_STMT(STMT)
108#define STMT(CLASS, PARENT)                              \
109    case Stmt::CLASS ## Class: DISPATCH(CLASS, CLASS);
110#include "clang/AST/StmtNodes.inc"
111    }
112  }
113
114  // If the implementation chooses not to implement a certain visit method, fall
115  // back on VisitExpr or whatever else is the superclass.
116#define STMT(CLASS, PARENT)                                   \
117  RetTy Visit ## CLASS(PTR(CLASS) S, ParamTys... P) { DISPATCH(PARENT, PARENT); }
118#include "clang/AST/StmtNodes.inc"
119
120  // If the implementation doesn't implement binary operator methods, fall back
121  // on VisitBinaryOperator.
122#define BINOP_FALLBACK(NAME) \
123  RetTy VisitBin ## NAME(PTR(BinaryOperator) S, ParamTys... P) { \
124    DISPATCH(BinaryOperator, BinaryOperator); \
125  }
126  BINOP_FALLBACK(PtrMemD)                    BINOP_FALLBACK(PtrMemI)
127  BINOP_FALLBACK(Mul)   BINOP_FALLBACK(Div)  BINOP_FALLBACK(Rem)
128  BINOP_FALLBACK(Add)   BINOP_FALLBACK(Sub)  BINOP_FALLBACK(Shl)
129  BINOP_FALLBACK(Shr)
130
131  BINOP_FALLBACK(LT)    BINOP_FALLBACK(GT)   BINOP_FALLBACK(LE)
132  BINOP_FALLBACK(GE)    BINOP_FALLBACK(EQ)   BINOP_FALLBACK(NE)
133  BINOP_FALLBACK(Cmp)
134
135  BINOP_FALLBACK(And)   BINOP_FALLBACK(Xor)  BINOP_FALLBACK(Or)
136  BINOP_FALLBACK(LAnd)  BINOP_FALLBACK(LOr)
137
138  BINOP_FALLBACK(Assign)
139  BINOP_FALLBACK(Comma)
140#undef BINOP_FALLBACK
141
142  // If the implementation doesn't implement compound assignment operator
143  // methods, fall back on VisitCompoundAssignOperator.
144#define CAO_FALLBACK(NAME) \
145  RetTy VisitBin ## NAME(PTR(CompoundAssignOperator) S, ParamTys... P) { \
146    DISPATCH(CompoundAssignOperator, CompoundAssignOperator); \
147  }
148  CAO_FALLBACK(MulAssign) CAO_FALLBACK(DivAssign) CAO_FALLBACK(RemAssign)
149  CAO_FALLBACK(AddAssign) CAO_FALLBACK(SubAssign) CAO_FALLBACK(ShlAssign)
150  CAO_FALLBACK(ShrAssign) CAO_FALLBACK(AndAssign) CAO_FALLBACK(OrAssign)
151  CAO_FALLBACK(XorAssign)
152#undef CAO_FALLBACK
153
154  // If the implementation doesn't implement unary operator methods, fall back
155  // on VisitUnaryOperator.
156#define UNARYOP_FALLBACK(NAME) \
157  RetTy VisitUnary ## NAME(PTR(UnaryOperator) S, ParamTys... P) { \
158    DISPATCH(UnaryOperator, UnaryOperator);    \
159  }
160  UNARYOP_FALLBACK(PostInc)   UNARYOP_FALLBACK(PostDec)
161  UNARYOP_FALLBACK(PreInc)    UNARYOP_FALLBACK(PreDec)
162  UNARYOP_FALLBACK(AddrOf)    UNARYOP_FALLBACK(Deref)
163
164  UNARYOP_FALLBACK(Plus)      UNARYOP_FALLBACK(Minus)
165  UNARYOP_FALLBACK(Not)       UNARYOP_FALLBACK(LNot)
166  UNARYOP_FALLBACK(Real)      UNARYOP_FALLBACK(Imag)
167  UNARYOP_FALLBACK(Extension) UNARYOP_FALLBACK(Coawait)
168#undef UNARYOP_FALLBACK
169
170  // Base case, ignore it. :)
171  RetTy VisitStmt(PTR(Stmt) Node, ParamTys... P) { return RetTy(); }
172
173#undef PTR
174#undef DISPATCH
175};
176
177/// StmtVisitor - This class implements a simple visitor for Stmt subclasses.
178/// Since Expr derives from Stmt, this also includes support for visiting Exprs.
179///
180/// This class does not preserve constness of Stmt pointers (see also
181/// ConstStmtVisitor).
182template <typename ImplClass, typename RetTy = void, typename... ParamTys>
183class StmtVisitor
184    : public StmtVisitorBase<std::add_pointer, ImplClass, RetTy, ParamTys...> {
185};
186
187/// ConstStmtVisitor - This class implements a simple visitor for Stmt
188/// subclasses. Since Expr derives from Stmt, this also includes support for
189/// visiting Exprs.
190///
191/// This class preserves constness of Stmt pointers (see also StmtVisitor).
192template <typename ImplClass, typename RetTy = void, typename... ParamTys>
193class ConstStmtVisitor : public StmtVisitorBase<llvm::make_const_ptr, ImplClass,
194                                                RetTy, ParamTys...> {};
195
196} // namespace clang
197
198#endif // LLVM_CLANG_AST_STMTVISITOR_H
199