1//===------------------------- MemberPointer.cpp ----------------*- 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#include "MemberPointer.h"
10#include "Context.h"
11#include "Program.h"
12#include "Record.h"
13
14namespace clang {
15namespace interp {
16
17std::optional<Pointer> MemberPointer::toPointer(const Context &Ctx) const {
18 if (!getDecl() || isa<FunctionDecl>(Val: getDecl()))
19 return Base;
20 assert((isa<FieldDecl, IndirectFieldDecl>(getDecl())));
21
22 if (!Base.isBlockPointer())
23 return std::nullopt;
24
25 unsigned BlockMDSize = Base.block()->getDescriptor()->getMetadataSize();
26
27 if (PtrOffset >= 0) {
28 // If the resulting base would be too small, return nullopt.
29 if (Base.BS.Base < static_cast<unsigned>(PtrOffset) ||
30 (Base.BS.Base - PtrOffset < BlockMDSize))
31 return std::nullopt;
32 }
33
34 Pointer CastedBase =
35 (PtrOffset < 0 ? Base.atField(Off: -PtrOffset) : Base.atFieldSub(Off: PtrOffset));
36
37 const Record *BaseRecord = CastedBase.getRecord();
38 if (!BaseRecord)
39 return std::nullopt;
40
41 unsigned Offset = 0;
42 Offset += BlockMDSize;
43
44 if (const auto *FD = dyn_cast<FieldDecl>(Val: getDecl())) {
45 if (FD->getParent() == BaseRecord->getDecl())
46 return CastedBase.atField(Off: BaseRecord->getField(FD)->Offset);
47
48 const RecordDecl *FieldParent = FD->getParent();
49 const Record *FieldRecord = Ctx.getRecord(D: FieldParent);
50
51 Offset += FieldRecord->getField(FD)->Offset;
52 if (Offset > CastedBase.block()->getSize())
53 return std::nullopt;
54
55 if (const RecordDecl *BaseDecl = Base.getDeclPtr().getRecord()->getDecl();
56 BaseDecl != FieldParent)
57 Offset += Ctx.collectBaseOffset(BaseDecl: FieldParent, DerivedDecl: BaseDecl);
58
59 } else {
60 const auto *IFD = cast<IndirectFieldDecl>(Val: getDecl());
61
62 for (const NamedDecl *ND : IFD->chain()) {
63 const FieldDecl *F = cast<FieldDecl>(Val: ND);
64 const RecordDecl *FieldParent = F->getParent();
65 const Record *FieldRecord = Ctx.getRecord(D: FieldParent);
66 Offset += FieldRecord->getField(FD: F)->Offset;
67 }
68 }
69
70 assert(BaseRecord);
71 if (Offset > CastedBase.block()->getSize())
72 return std::nullopt;
73
74 assert(Offset <= CastedBase.block()->getSize());
75 return Pointer(const_cast<Block *>(Base.block()), Offset, Offset);
76}
77
78APValue MemberPointer::toAPValue(const ASTContext &ASTCtx) const {
79 if (isZero())
80 return APValue(static_cast<ValueDecl *>(nullptr), /*IsDerivedMember=*/false,
81 /*Path=*/{});
82
83 if (hasBase())
84 return Base.toAPValue(ASTCtx);
85
86 return APValue(getDecl(), /*IsDerivedMember=*/isDerivedMember(),
87 /*Path=*/ArrayRef(Path, PathLength));
88}
89
90ComparisonCategoryResult
91MemberPointer::compare(const MemberPointer &RHS) const {
92 if (this->getDecl() == RHS.getDecl()) {
93
94 if (this->PathLength != RHS.PathLength)
95 return ComparisonCategoryResult::Unordered;
96
97 if (PathLength != 0 &&
98 std::memcmp(s1: Path, s2: RHS.Path, n: PathLength * sizeof(CXXRecordDecl *)) != 0)
99 return ComparisonCategoryResult::Unordered;
100
101 return ComparisonCategoryResult::Equal;
102 }
103 return ComparisonCategoryResult::Unordered;
104}
105
106} // namespace interp
107} // namespace clang
108