1 //===- UsedDeclVisitor.h - ODR-used declarations visitor --------*- 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 //  This file defines UsedDeclVisitor, a CRTP class which visits all the
9 //  declarations that are ODR-used by an expression or statement.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LIB_SEMA_USEDDECLVISITOR_H
14 #define LLVM_CLANG_LIB_SEMA_USEDDECLVISITOR_H
15 
16 #include "clang/AST/EvaluatedExprVisitor.h"
17 #include "clang/Sema/SemaInternal.h"
18 
19 namespace clang {
20 template <class Derived>
21 class UsedDeclVisitor : public EvaluatedExprVisitor<Derived> {
22 protected:
23   Sema &S;
24 
25 public:
26   typedef EvaluatedExprVisitor<Derived> Inherited;
27 
28   UsedDeclVisitor(Sema &S) : Inherited(S.Context), S(S) {}
29 
30   Derived &asImpl() { return *static_cast<Derived *>(this); }
31 
32   void VisitDeclRefExpr(DeclRefExpr *E) {
33     auto *D = E->getDecl();
34     if (isa<FunctionDecl>(D) || isa<VarDecl>(D)) {
35       asImpl().visitUsedDecl(E->getLocation(), D);
36     }
37   }
38 
39   void VisitMemberExpr(MemberExpr *E) {
40     auto *D = E->getMemberDecl();
41     if (isa<FunctionDecl>(D) || isa<VarDecl>(D)) {
42       asImpl().visitUsedDecl(E->getMemberLoc(), D);
43     }
44     asImpl().Visit(E->getBase());
45   }
46 
47   void VisitCapturedStmt(CapturedStmt *Node) {
48     asImpl().visitUsedDecl(Node->getBeginLoc(), Node->getCapturedDecl());
49     Inherited::VisitCapturedStmt(Node);
50   }
51 
52   void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
53     asImpl().visitUsedDecl(
54         E->getBeginLoc(),
55         const_cast<CXXDestructorDecl *>(E->getTemporary()->getDestructor()));
56     asImpl().Visit(E->getSubExpr());
57   }
58 
59   void VisitCXXNewExpr(CXXNewExpr *E) {
60     if (E->getOperatorNew())
61       asImpl().visitUsedDecl(E->getBeginLoc(), E->getOperatorNew());
62     if (E->getOperatorDelete())
63       asImpl().visitUsedDecl(E->getBeginLoc(), E->getOperatorDelete());
64     Inherited::VisitCXXNewExpr(E);
65   }
66 
67   void VisitCXXDeleteExpr(CXXDeleteExpr *E) {
68     if (E->getOperatorDelete())
69       asImpl().visitUsedDecl(E->getBeginLoc(), E->getOperatorDelete());
70     QualType DestroyedOrNull = E->getDestroyedType();
71     if (!DestroyedOrNull.isNull()) {
72       QualType Destroyed = S.Context.getBaseElementType(DestroyedOrNull);
73       if (const RecordType *DestroyedRec = Destroyed->getAs<RecordType>()) {
74         CXXRecordDecl *Record = cast<CXXRecordDecl>(DestroyedRec->getDecl());
75         if (Record->getDefinition())
76           asImpl().visitUsedDecl(E->getBeginLoc(), S.LookupDestructor(Record));
77       }
78     }
79 
80     Inherited::VisitCXXDeleteExpr(E);
81   }
82 
83   void VisitCXXConstructExpr(CXXConstructExpr *E) {
84     asImpl().visitUsedDecl(E->getBeginLoc(), E->getConstructor());
85     CXXConstructorDecl *D = E->getConstructor();
86     for (const CXXCtorInitializer *Init : D->inits()) {
87       if (Init->isInClassMemberInitializer())
88         asImpl().Visit(Init->getInit());
89     }
90     Inherited::VisitCXXConstructExpr(E);
91   }
92 
93   void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
94     asImpl().Visit(E->getExpr());
95     Inherited::VisitCXXDefaultArgExpr(E);
96   }
97 
98   void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *E) {
99     asImpl().Visit(E->getExpr());
100     Inherited::VisitCXXDefaultInitExpr(E);
101   }
102 
103   void VisitInitListExpr(InitListExpr *ILE) {
104     if (ILE->hasArrayFiller())
105       asImpl().Visit(ILE->getArrayFiller());
106     Inherited::VisitInitListExpr(ILE);
107   }
108 
109   void visitUsedDecl(SourceLocation Loc, Decl *D) {
110     if (auto *CD = dyn_cast<CapturedDecl>(D)) {
111       if (auto *S = CD->getBody()) {
112         asImpl().Visit(S);
113       }
114     } else if (auto *CD = dyn_cast<BlockDecl>(D)) {
115       if (auto *S = CD->getBody()) {
116         asImpl().Visit(S);
117       }
118     }
119   }
120 };
121 } // end namespace clang
122 
123 #endif // LLVM_CLANG_LIB_SEMA_USEDDECLVISITOR_H
124