xref: /freebsd/contrib/llvm-project/clang/lib/AST/Interp/MemberPointer.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 "FunctionPointer.h"
12 #include "Program.h"
13 #include "Record.h"
14 
15 namespace clang {
16 namespace interp {
17 
toPointer(const Context & Ctx) const18 std::optional<Pointer> MemberPointer::toPointer(const Context &Ctx) const {
19   if (!Dcl || isa<FunctionDecl>(Dcl))
20     return Base;
21   const FieldDecl *FD = cast<FieldDecl>(Dcl);
22   assert(FD);
23 
24   if (!Base.isBlockPointer())
25     return std::nullopt;
26 
27   Pointer CastedBase =
28       (PtrOffset < 0 ? Base.atField(-PtrOffset) : Base.atFieldSub(PtrOffset));
29 
30   const Record *BaseRecord = CastedBase.getRecord();
31   if (!BaseRecord)
32     return std::nullopt;
33 
34   assert(BaseRecord);
35   if (FD->getParent() == BaseRecord->getDecl())
36     return CastedBase.atField(BaseRecord->getField(FD)->Offset);
37 
38   const RecordDecl *FieldParent = FD->getParent();
39   const Record *FieldRecord = Ctx.getRecord(FieldParent);
40 
41   unsigned Offset = 0;
42   Offset += FieldRecord->getField(FD)->Offset;
43   Offset += CastedBase.block()->getDescriptor()->getMetadataSize();
44 
45   if (Offset > CastedBase.block()->getSize())
46     return std::nullopt;
47 
48   if (const RecordDecl *BaseDecl = Base.getDeclPtr().getRecord()->getDecl();
49       BaseDecl != FieldParent)
50     Offset += Ctx.collectBaseOffset(FieldParent, BaseDecl);
51 
52   if (Offset > CastedBase.block()->getSize())
53     return std::nullopt;
54 
55   assert(Offset <= CastedBase.block()->getSize());
56   return Pointer(const_cast<Block *>(Base.block()), Offset, Offset);
57 }
58 
toFunctionPointer(const Context & Ctx) const59 FunctionPointer MemberPointer::toFunctionPointer(const Context &Ctx) const {
60   return FunctionPointer(Ctx.getProgram().getFunction(cast<FunctionDecl>(Dcl)));
61 }
62 
toAPValue(const ASTContext & ASTCtx) const63 APValue MemberPointer::toAPValue(const ASTContext &ASTCtx) const {
64   if (isZero())
65     return APValue(static_cast<ValueDecl *>(nullptr), /*IsDerivedMember=*/false,
66                    /*Path=*/{});
67 
68   if (hasBase())
69     return Base.toAPValue(ASTCtx);
70 
71   return APValue(cast<ValueDecl>(getDecl()), /*IsDerivedMember=*/false,
72                  /*Path=*/{});
73 }
74 
75 } // namespace interp
76 } // namespace clang
77