xref: /llvm-project/clang/include/clang/AST/StmtVisitor.h (revision 8fb42300a02c887740825cd1b60fc4fcd8d2f933)
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/ExprCXX.h"
17 #include "clang/AST/ExprConcepts.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/StmtOpenACC.h"
24 #include "clang/AST/StmtOpenMP.h"
25 #include "clang/AST/StmtSYCL.h"
26 #include "clang/Basic/LLVM.h"
27 #include "llvm/ADT/STLExtras.h"
28 #include "llvm/Support/Casting.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include <utility>
31 
32 namespace clang {
33 /// StmtVisitorBase - This class implements a simple visitor for Stmt
34 /// subclasses. Since Expr derives from Stmt, this also includes support for
35 /// visiting Exprs.
36 template<template <typename> class Ptr, typename ImplClass, typename RetTy=void,
37          class... ParamTys>
38 class StmtVisitorBase {
39 public:
40 #define PTR(CLASS) typename Ptr<CLASS>::type
41 #define DISPATCH(NAME, CLASS) \
42   return static_cast<ImplClass*>(this)->Visit ## NAME( \
43     static_cast<PTR(CLASS)>(S), std::forward<ParamTys>(P)...)
44 
45   RetTy Visit(PTR(Stmt) S, ParamTys... P) {
46     // If we have a binary expr, dispatch to the subcode of the binop.  A smart
47     // optimizer (e.g. LLVM) will fold this comparison into the switch stmt
48     // below.
49     if (PTR(BinaryOperator) BinOp = dyn_cast<BinaryOperator>(S)) {
50       switch (BinOp->getOpcode()) {
51       case BO_PtrMemD:   DISPATCH(BinPtrMemD,   BinaryOperator);
52       case BO_PtrMemI:   DISPATCH(BinPtrMemI,   BinaryOperator);
53       case BO_Mul:       DISPATCH(BinMul,       BinaryOperator);
54       case BO_Div:       DISPATCH(BinDiv,       BinaryOperator);
55       case BO_Rem:       DISPATCH(BinRem,       BinaryOperator);
56       case BO_Add:       DISPATCH(BinAdd,       BinaryOperator);
57       case BO_Sub:       DISPATCH(BinSub,       BinaryOperator);
58       case BO_Shl:       DISPATCH(BinShl,       BinaryOperator);
59       case BO_Shr:       DISPATCH(BinShr,       BinaryOperator);
60 
61       case BO_LT:        DISPATCH(BinLT,        BinaryOperator);
62       case BO_GT:        DISPATCH(BinGT,        BinaryOperator);
63       case BO_LE:        DISPATCH(BinLE,        BinaryOperator);
64       case BO_GE:        DISPATCH(BinGE,        BinaryOperator);
65       case BO_EQ:        DISPATCH(BinEQ,        BinaryOperator);
66       case BO_NE:        DISPATCH(BinNE,        BinaryOperator);
67       case BO_Cmp:       DISPATCH(BinCmp,       BinaryOperator);
68 
69       case BO_And:       DISPATCH(BinAnd,       BinaryOperator);
70       case BO_Xor:       DISPATCH(BinXor,       BinaryOperator);
71       case BO_Or :       DISPATCH(BinOr,        BinaryOperator);
72       case BO_LAnd:      DISPATCH(BinLAnd,      BinaryOperator);
73       case BO_LOr :      DISPATCH(BinLOr,       BinaryOperator);
74       case BO_Assign:    DISPATCH(BinAssign,    BinaryOperator);
75       case BO_MulAssign: DISPATCH(BinMulAssign, CompoundAssignOperator);
76       case BO_DivAssign: DISPATCH(BinDivAssign, CompoundAssignOperator);
77       case BO_RemAssign: DISPATCH(BinRemAssign, CompoundAssignOperator);
78       case BO_AddAssign: DISPATCH(BinAddAssign, CompoundAssignOperator);
79       case BO_SubAssign: DISPATCH(BinSubAssign, CompoundAssignOperator);
80       case BO_ShlAssign: DISPATCH(BinShlAssign, CompoundAssignOperator);
81       case BO_ShrAssign: DISPATCH(BinShrAssign, CompoundAssignOperator);
82       case BO_AndAssign: DISPATCH(BinAndAssign, CompoundAssignOperator);
83       case BO_OrAssign:  DISPATCH(BinOrAssign,  CompoundAssignOperator);
84       case BO_XorAssign: DISPATCH(BinXorAssign, CompoundAssignOperator);
85       case BO_Comma:     DISPATCH(BinComma,     BinaryOperator);
86       }
87     } else if (PTR(UnaryOperator) UnOp = dyn_cast<UnaryOperator>(S)) {
88       switch (UnOp->getOpcode()) {
89       case UO_PostInc:   DISPATCH(UnaryPostInc,   UnaryOperator);
90       case UO_PostDec:   DISPATCH(UnaryPostDec,   UnaryOperator);
91       case UO_PreInc:    DISPATCH(UnaryPreInc,    UnaryOperator);
92       case UO_PreDec:    DISPATCH(UnaryPreDec,    UnaryOperator);
93       case UO_AddrOf:    DISPATCH(UnaryAddrOf,    UnaryOperator);
94       case UO_Deref:     DISPATCH(UnaryDeref,     UnaryOperator);
95       case UO_Plus:      DISPATCH(UnaryPlus,      UnaryOperator);
96       case UO_Minus:     DISPATCH(UnaryMinus,     UnaryOperator);
97       case UO_Not:       DISPATCH(UnaryNot,       UnaryOperator);
98       case UO_LNot:      DISPATCH(UnaryLNot,      UnaryOperator);
99       case UO_Real:      DISPATCH(UnaryReal,      UnaryOperator);
100       case UO_Imag:      DISPATCH(UnaryImag,      UnaryOperator);
101       case UO_Extension: DISPATCH(UnaryExtension, UnaryOperator);
102       case UO_Coawait:   DISPATCH(UnaryCoawait,   UnaryOperator);
103       }
104     }
105 
106     // Top switch stmt: dispatch to VisitFooStmt for each FooStmt.
107     switch (S->getStmtClass()) {
108     default: llvm_unreachable("Unknown stmt kind!");
109 #define ABSTRACT_STMT(STMT)
110 #define STMT(CLASS, PARENT)                              \
111     case Stmt::CLASS ## Class: DISPATCH(CLASS, CLASS);
112 #include "clang/AST/StmtNodes.inc"
113     }
114   }
115 
116   // If the implementation chooses not to implement a certain visit method, fall
117   // back on VisitExpr or whatever else is the superclass.
118 #define STMT(CLASS, PARENT)                                   \
119   RetTy Visit ## CLASS(PTR(CLASS) S, ParamTys... P) { DISPATCH(PARENT, PARENT); }
120 #include "clang/AST/StmtNodes.inc"
121 
122   // If the implementation doesn't implement binary operator methods, fall back
123   // on VisitBinaryOperator.
124 #define BINOP_FALLBACK(NAME) \
125   RetTy VisitBin ## NAME(PTR(BinaryOperator) S, ParamTys... P) { \
126     DISPATCH(BinaryOperator, BinaryOperator); \
127   }
128   BINOP_FALLBACK(PtrMemD)                    BINOP_FALLBACK(PtrMemI)
129   BINOP_FALLBACK(Mul)   BINOP_FALLBACK(Div)  BINOP_FALLBACK(Rem)
130   BINOP_FALLBACK(Add)   BINOP_FALLBACK(Sub)  BINOP_FALLBACK(Shl)
131   BINOP_FALLBACK(Shr)
132 
133   BINOP_FALLBACK(LT)    BINOP_FALLBACK(GT)   BINOP_FALLBACK(LE)
134   BINOP_FALLBACK(GE)    BINOP_FALLBACK(EQ)   BINOP_FALLBACK(NE)
135   BINOP_FALLBACK(Cmp)
136 
137   BINOP_FALLBACK(And)   BINOP_FALLBACK(Xor)  BINOP_FALLBACK(Or)
138   BINOP_FALLBACK(LAnd)  BINOP_FALLBACK(LOr)
139 
140   BINOP_FALLBACK(Assign)
141   BINOP_FALLBACK(Comma)
142 #undef BINOP_FALLBACK
143 
144   // If the implementation doesn't implement compound assignment operator
145   // methods, fall back on VisitCompoundAssignOperator.
146 #define CAO_FALLBACK(NAME) \
147   RetTy VisitBin ## NAME(PTR(CompoundAssignOperator) S, ParamTys... P) { \
148     DISPATCH(CompoundAssignOperator, CompoundAssignOperator); \
149   }
150   CAO_FALLBACK(MulAssign) CAO_FALLBACK(DivAssign) CAO_FALLBACK(RemAssign)
151   CAO_FALLBACK(AddAssign) CAO_FALLBACK(SubAssign) CAO_FALLBACK(ShlAssign)
152   CAO_FALLBACK(ShrAssign) CAO_FALLBACK(AndAssign) CAO_FALLBACK(OrAssign)
153   CAO_FALLBACK(XorAssign)
154 #undef CAO_FALLBACK
155 
156   // If the implementation doesn't implement unary operator methods, fall back
157   // on VisitUnaryOperator.
158 #define UNARYOP_FALLBACK(NAME) \
159   RetTy VisitUnary ## NAME(PTR(UnaryOperator) S, ParamTys... P) { \
160     DISPATCH(UnaryOperator, UnaryOperator);    \
161   }
162   UNARYOP_FALLBACK(PostInc)   UNARYOP_FALLBACK(PostDec)
163   UNARYOP_FALLBACK(PreInc)    UNARYOP_FALLBACK(PreDec)
164   UNARYOP_FALLBACK(AddrOf)    UNARYOP_FALLBACK(Deref)
165 
166   UNARYOP_FALLBACK(Plus)      UNARYOP_FALLBACK(Minus)
167   UNARYOP_FALLBACK(Not)       UNARYOP_FALLBACK(LNot)
168   UNARYOP_FALLBACK(Real)      UNARYOP_FALLBACK(Imag)
169   UNARYOP_FALLBACK(Extension) UNARYOP_FALLBACK(Coawait)
170 #undef UNARYOP_FALLBACK
171 
172   // Base case, ignore it. :)
173   RetTy VisitStmt(PTR(Stmt) Node, ParamTys... P) { return RetTy(); }
174 
175 #undef PTR
176 #undef DISPATCH
177 };
178 
179 /// StmtVisitor - This class implements a simple visitor for Stmt subclasses.
180 /// Since Expr derives from Stmt, this also includes support for visiting Exprs.
181 ///
182 /// This class does not preserve constness of Stmt pointers (see also
183 /// ConstStmtVisitor).
184 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
185 class StmtVisitor
186     : public StmtVisitorBase<std::add_pointer, ImplClass, RetTy, ParamTys...> {
187 };
188 
189 /// ConstStmtVisitor - This class implements a simple visitor for Stmt
190 /// subclasses. Since Expr derives from Stmt, this also includes support for
191 /// visiting Exprs.
192 ///
193 /// This class preserves constness of Stmt pointers (see also StmtVisitor).
194 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
195 class ConstStmtVisitor : public StmtVisitorBase<llvm::make_const_ptr, ImplClass,
196                                                 RetTy, ParamTys...> {};
197 
198 } // namespace clang
199 
200 #endif // LLVM_CLANG_AST_STMTVISITOR_H
201