RecordLayout.cpp revision 1.1.1.1 
1//===- RecordLayout.cpp - Layout information for a struct/union -----------===//
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 RecordLayout interface.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/RecordLayout.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/Basic/TargetCXXABI.h"
16#include "clang/Basic/TargetInfo.h"
17#include <cassert>
18
19using namespace clang;
20
21void ASTRecordLayout::Destroy(ASTContext &Ctx) {
22  if (CXXInfo) {
23    CXXInfo->~CXXRecordLayoutInfo();
24    Ctx.Deallocate(CXXInfo);
25  }
26  this->~ASTRecordLayout();
27  Ctx.Deallocate(this);
28}
29
30ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx, CharUnits size,
31                                 CharUnits alignment,
32                                 CharUnits unadjustedAlignment,
33                                 CharUnits requiredAlignment,
34                                 CharUnits datasize,
35                                 ArrayRef<uint64_t> fieldoffsets)
36    : Size(size), DataSize(datasize), Alignment(alignment),
37      UnadjustedAlignment(unadjustedAlignment),
38      RequiredAlignment(requiredAlignment) {
39  FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
40}
41
42// Constructor for C++ records.
43ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx,
44                                 CharUnits size, CharUnits alignment,
45                                 CharUnits unadjustedAlignment,
46                                 CharUnits requiredAlignment,
47                                 bool hasOwnVFPtr, bool hasExtendableVFPtr,
48                                 CharUnits vbptroffset,
49                                 CharUnits datasize,
50                                 ArrayRef<uint64_t> fieldoffsets,
51                                 CharUnits nonvirtualsize,
52                                 CharUnits nonvirtualalignment,
53                                 CharUnits SizeOfLargestEmptySubobject,
54                                 const CXXRecordDecl *PrimaryBase,
55                                 bool IsPrimaryBaseVirtual,
56                                 const CXXRecordDecl *BaseSharingVBPtr,
57                                 bool EndsWithZeroSizedObject,
58                                 bool LeadsWithZeroSizedBase,
59                                 const BaseOffsetsMapTy& BaseOffsets,
60                                 const VBaseOffsetsMapTy& VBaseOffsets)
61  : Size(size), DataSize(datasize), Alignment(alignment),
62    UnadjustedAlignment(unadjustedAlignment),
63    RequiredAlignment(requiredAlignment), CXXInfo(new (Ctx) CXXRecordLayoutInfo)
64{
65  FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
66
67  CXXInfo->PrimaryBase.setPointer(PrimaryBase);
68  CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
69  CXXInfo->NonVirtualSize = nonvirtualsize;
70  CXXInfo->NonVirtualAlignment = nonvirtualalignment;
71  CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
72  CXXInfo->BaseOffsets = BaseOffsets;
73  CXXInfo->VBaseOffsets = VBaseOffsets;
74  CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
75  CXXInfo->VBPtrOffset = vbptroffset;
76  CXXInfo->HasExtendableVFPtr = hasExtendableVFPtr;
77  CXXInfo->BaseSharingVBPtr = BaseSharingVBPtr;
78  CXXInfo->EndsWithZeroSizedObject = EndsWithZeroSizedObject;
79  CXXInfo->LeadsWithZeroSizedBase = LeadsWithZeroSizedBase;
80
81#ifndef NDEBUG
82    if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
83      if (isPrimaryBaseVirtual()) {
84        if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
85          assert(getVBaseClassOffset(PrimaryBase).isZero() &&
86                 "Primary virtual base must be at offset 0!");
87        }
88      } else {
89        assert(getBaseClassOffset(PrimaryBase).isZero() &&
90               "Primary base must be at offset 0!");
91      }
92    }
93#endif
94}
95