1 /**
2  * Provides a visitor class visiting all AST nodes present in the compiler.
3  *
4  * Copyright:   Copyright (C) 1999-2021 by The D Language Foundation, All Rights Reserved
5  * Authors:     $(LINK2 http://www.digitalmars.com, Walter Bright)
6  * License:     $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
7  * Source:      $(LINK2 https://github.com/dlang/dmd/blob/master/src/dmd/visitor.d, _visitor.d)
8  * Documentation:  https://dlang.org/phobos/dmd_visitor.html
9  * Coverage:    https://codecov.io/gh/dlang/dmd/src/master/src/dmd/visitor.d
10  */
11 
12 module dmd.visitor;
13 
14 import dmd.astcodegen;
15 import dmd.parsetimevisitor;
16 import dmd.tokens;
17 import dmd.transitivevisitor;
18 import dmd.expression;
19 import dmd.root.rootobject;
20 
21 /**
22  * Classic Visitor class which implements visit methods for all the AST
23  * nodes present in the compiler. The visit methods for AST nodes
24  * created at parse time are inherited while the visiting methods
25  * for AST nodes created at semantic time are implemented.
26  */
27 extern (C++) class Visitor : ParseTimeVisitor!ASTCodegen
28 {
29     alias visit = ParseTimeVisitor!ASTCodegen.visit;
30 public:
31     void visit(ASTCodegen.ErrorStatement s) { visit(cast(ASTCodegen.Statement)s); }
32     void visit(ASTCodegen.PeelStatement s) { visit(cast(ASTCodegen.Statement)s); }
33     void visit(ASTCodegen.UnrolledLoopStatement s) { visit(cast(ASTCodegen.Statement)s); }
34     void visit(ASTCodegen.SwitchErrorStatement s) { visit(cast(ASTCodegen.Statement)s); }
35     void visit(ASTCodegen.DebugStatement s) { visit(cast(ASTCodegen.Statement)s); }
36     void visit(ASTCodegen.DtorExpStatement s) { visit(cast(ASTCodegen.ExpStatement)s); }
37     void visit(ASTCodegen.ForwardingStatement s) { visit(cast(ASTCodegen.Statement)s); }
38     void visit(ASTCodegen.OverloadSet s) { visit(cast(ASTCodegen.Dsymbol)s); }
39     void visit(ASTCodegen.LabelDsymbol s) { visit(cast(ASTCodegen.Dsymbol)s); }
40     void visit(ASTCodegen.WithScopeSymbol s) { visit(cast(ASTCodegen.ScopeDsymbol)s); }
41     void visit(ASTCodegen.ArrayScopeSymbol s) { visit(cast(ASTCodegen.ScopeDsymbol)s); }
42     void visit(ASTCodegen.OverDeclaration s) { visit(cast(ASTCodegen.Declaration)s); }
43     void visit(ASTCodegen.SymbolDeclaration s) { visit(cast(ASTCodegen.Declaration)s); }
44     void visit(ASTCodegen.ForwardingAttribDeclaration s) { visit(cast(ASTCodegen.AttribDeclaration)s); }
45     void visit(ASTCodegen.ThisDeclaration s) { visit(cast(ASTCodegen.VarDeclaration)s); }
46     void visit(ASTCodegen.TypeInfoDeclaration s) { visit(cast(ASTCodegen.VarDeclaration)s); }
47     void visit(ASTCodegen.TypeInfoStructDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
48     void visit(ASTCodegen.TypeInfoClassDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
49     void visit(ASTCodegen.TypeInfoInterfaceDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
50     void visit(ASTCodegen.TypeInfoPointerDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
51     void visit(ASTCodegen.TypeInfoArrayDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
52     void visit(ASTCodegen.TypeInfoStaticArrayDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
53     void visit(ASTCodegen.TypeInfoAssociativeArrayDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
54     void visit(ASTCodegen.TypeInfoEnumDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
55     void visit(ASTCodegen.TypeInfoFunctionDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
56     void visit(ASTCodegen.TypeInfoDelegateDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
57     void visit(ASTCodegen.TypeInfoTupleDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
58     void visit(ASTCodegen.TypeInfoConstDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
59     void visit(ASTCodegen.TypeInfoInvariantDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
60     void visit(ASTCodegen.TypeInfoSharedDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
61     void visit(ASTCodegen.TypeInfoWildDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
62     void visit(ASTCodegen.TypeInfoVectorDeclaration s) { visit(cast(ASTCodegen.TypeInfoDeclaration)s); }
63     void visit(ASTCodegen.FuncAliasDeclaration s) { visit(cast(ASTCodegen.FuncDeclaration)s); }
64     void visit(ASTCodegen.ErrorInitializer i) { visit(cast(ASTCodegen.Initializer)i); }
65     void visit(ASTCodegen.ErrorExp e) { visit(cast(ASTCodegen.Expression)e); }
66     void visit(ASTCodegen.ComplexExp e) { visit(cast(ASTCodegen.Expression)e); }
67     void visit(ASTCodegen.StructLiteralExp e) { visit(cast(ASTCodegen.Expression)e); }
68     void visit(ASTCodegen.ObjcClassReferenceExp e) { visit(cast(ASTCodegen.Expression)e); }
69     void visit(ASTCodegen.SymOffExp e) { visit(cast(ASTCodegen.SymbolExp)e); }
70     void visit(ASTCodegen.OverExp e) { visit(cast(ASTCodegen.Expression)e); }
71     void visit(ASTCodegen.HaltExp e) { visit(cast(ASTCodegen.Expression)e); }
72     void visit(ASTCodegen.DotTemplateExp e) { visit(cast(ASTCodegen.UnaExp)e); }
73     void visit(ASTCodegen.DotVarExp e) { visit(cast(ASTCodegen.UnaExp)e); }
74     void visit(ASTCodegen.DelegateExp e) { visit(cast(ASTCodegen.UnaExp)e); }
75     void visit(ASTCodegen.DotTypeExp e) { visit(cast(ASTCodegen.UnaExp)e); }
76     void visit(ASTCodegen.VectorExp e) { visit(cast(ASTCodegen.UnaExp)e); }
77     void visit(ASTCodegen.VectorArrayExp e) { visit(cast(ASTCodegen.UnaExp)e); }
78     void visit(ASTCodegen.SliceExp e) { visit(cast(ASTCodegen.UnaExp)e); }
79     void visit(ASTCodegen.ArrayLengthExp e) { visit(cast(ASTCodegen.UnaExp)e); }
80     void visit(ASTCodegen.DelegatePtrExp e) { visit(cast(ASTCodegen.UnaExp)e); }
81     void visit(ASTCodegen.DelegateFuncptrExp e) { visit(cast(ASTCodegen.UnaExp)e); }
82     void visit(ASTCodegen.DotExp e) { visit(cast(ASTCodegen.BinExp)e); }
83     void visit(ASTCodegen.IndexExp e) { visit(cast(ASTCodegen.BinExp)e); }
84     void visit(ASTCodegen.ConstructExp e) { visit(cast(ASTCodegen.AssignExp)e); }
85     void visit(ASTCodegen.BlitExp e) { visit(cast(ASTCodegen.AssignExp)e); }
86     void visit(ASTCodegen.RemoveExp e) { visit(cast(ASTCodegen.BinExp)e); }
87     void visit(ASTCodegen.ClassReferenceExp e) { visit(cast(ASTCodegen.Expression)e); }
88     void visit(ASTCodegen.VoidInitExp e) { visit(cast(ASTCodegen.Expression)e); }
89     void visit(ASTCodegen.ThrownExceptionExp e) { visit(cast(ASTCodegen.Expression)e); }
90 }
91 
92 /**
93  * The PermissiveVisitor overrides the root AST nodes with
94  * empty visiting methods.
95  */
96 extern (C++) class SemanticTimePermissiveVisitor : Visitor
97 {
98     alias visit = Visitor.visit;
99 
100     override void visit(ASTCodegen.Dsymbol){}
101     override void visit(ASTCodegen.Parameter){}
102     override void visit(ASTCodegen.Statement){}
103     override void visit(ASTCodegen.Type){}
104     override void visit(ASTCodegen.Expression){}
105     override void visit(ASTCodegen.TemplateParameter){}
106     override void visit(ASTCodegen.Condition){}
107     override void visit(ASTCodegen.Initializer){}
108 }
109 
110 /**
111  * The TransitiveVisitor implements the AST traversal logic for all AST nodes.
112  */
113 extern (C++) class SemanticTimeTransitiveVisitor : SemanticTimePermissiveVisitor
114 {
115     alias visit = SemanticTimePermissiveVisitor.visit;
116 
117     mixin ParseVisitMethods!ASTCodegen __methods;
118     alias visit = __methods.visit;
119 
120     override void visit(ASTCodegen.PeelStatement s)
121     {
122         if (s.s)
123             s.s.accept(this);
124     }
125 
126     override void visit(ASTCodegen.UnrolledLoopStatement s)
127     {
128         foreach(sx; *s.statements)
129         {
130             if (sx)
131                 sx.accept(this);
132         }
133     }
134 
135     override void visit(ASTCodegen.DebugStatement s)
136     {
137         if (s.statement)
138             s.statement.accept(this);
139     }
140 
141     override void visit(ASTCodegen.ForwardingStatement s)
142     {
143         if (s.statement)
144             s.statement.accept(this);
145     }
146 
147     override void visit(ASTCodegen.StructLiteralExp e)
148     {
149         // CTFE can generate struct literals that contain an AddrExp pointing to themselves,
150         // need to avoid infinite recursion.
151         if (!(e.stageflags & stageToCBuffer))
152         {
153             int old = e.stageflags;
154             e.stageflags |= stageToCBuffer;
155             foreach (el; *e.elements)
156                 if (el)
157                     el.accept(this);
158             e.stageflags = old;
159         }
160     }
161 
162     override void visit(ASTCodegen.DotTemplateExp e)
163     {
164         e.e1.accept(this);
165     }
166 
167     override void visit(ASTCodegen.DotVarExp e)
168     {
169         e.e1.accept(this);
170     }
171 
172     override void visit(ASTCodegen.DelegateExp e)
173     {
174         if (!e.func.isNested() || e.func.needThis())
175             e.e1.accept(this);
176     }
177 
178     override void visit(ASTCodegen.DotTypeExp e)
179     {
180         e.e1.accept(this);
181     }
182 
183     override void visit(ASTCodegen.VectorExp e)
184     {
185         visitType(e.to);
186         e.e1.accept(this);
187     }
188 
189     override void visit(ASTCodegen.VectorArrayExp e)
190     {
191         e.e1.accept(this);
192     }
193 
194     override void visit(ASTCodegen.SliceExp e)
195     {
196         e.e1.accept(this);
197         if (e.upr)
198             e.upr.accept(this);
199         if (e.lwr)
200             e.lwr.accept(this);
201     }
202 
203     override void visit(ASTCodegen.ArrayLengthExp e)
204     {
205         e.e1.accept(this);
206     }
207 
208     override void visit(ASTCodegen.DelegatePtrExp e)
209     {
210         e.e1.accept(this);
211     }
212 
213     override void visit(ASTCodegen.DelegateFuncptrExp e)
214     {
215         e.e1.accept(this);
216     }
217 
218     override void visit(ASTCodegen.DotExp e)
219     {
220         e.e1.accept(this);
221         e.e2.accept(this);
222     }
223 
224     override void visit(ASTCodegen.IndexExp e)
225     {
226         e.e1.accept(this);
227         e.e2.accept(this);
228     }
229 
230     override void visit(ASTCodegen.RemoveExp e)
231     {
232         e.e1.accept(this);
233         e.e2.accept(this);
234     }
235 }
236 
237 extern (C++) class StoppableVisitor : Visitor
238 {
239     alias visit = Visitor.visit;
240 public:
241     bool stop;
242 
243     final extern (D) this()
244     {
245     }
246 }