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 preferredAlignment,
33                                 CharUnits unadjustedAlignment,
34                                 CharUnits requiredAlignment,
35                                 CharUnits datasize,
36                                 ArrayRef<uint64_t> fieldoffsets)
37    : Size(size), DataSize(datasize), Alignment(alignment),
38      PreferredAlignment(preferredAlignment),
39      UnadjustedAlignment(unadjustedAlignment),
40      RequiredAlignment(requiredAlignment) {
41  FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
42}
43
44// Constructor for C++ records.
45ASTRecordLayout::ASTRecordLayout(
46    const ASTContext &Ctx, CharUnits size, CharUnits alignment,
47    CharUnits preferredAlignment, CharUnits unadjustedAlignment,
48    CharUnits requiredAlignment, bool hasOwnVFPtr, bool hasExtendableVFPtr,
49    CharUnits vbptroffset, CharUnits datasize, ArrayRef<uint64_t> fieldoffsets,
50    CharUnits nonvirtualsize, CharUnits nonvirtualalignment,
51    CharUnits preferrednvalignment, CharUnits SizeOfLargestEmptySubobject,
52    const CXXRecordDecl *PrimaryBase, bool IsPrimaryBaseVirtual,
53    const CXXRecordDecl *BaseSharingVBPtr, bool EndsWithZeroSizedObject,
54    bool LeadsWithZeroSizedBase, const BaseOffsetsMapTy &BaseOffsets,
55    const VBaseOffsetsMapTy &VBaseOffsets)
56    : Size(size), DataSize(datasize), Alignment(alignment),
57      PreferredAlignment(preferredAlignment),
58      UnadjustedAlignment(unadjustedAlignment),
59      RequiredAlignment(requiredAlignment),
60      CXXInfo(new (Ctx) CXXRecordLayoutInfo) {
61  FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
62
63  CXXInfo->PrimaryBase.setPointer(PrimaryBase);
64  CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
65  CXXInfo->NonVirtualSize = nonvirtualsize;
66  CXXInfo->NonVirtualAlignment = nonvirtualalignment;
67  CXXInfo->PreferredNVAlignment = preferrednvalignment;
68  CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
69  CXXInfo->BaseOffsets = BaseOffsets;
70  CXXInfo->VBaseOffsets = VBaseOffsets;
71  CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
72  CXXInfo->VBPtrOffset = vbptroffset;
73  CXXInfo->HasExtendableVFPtr = hasExtendableVFPtr;
74  CXXInfo->BaseSharingVBPtr = BaseSharingVBPtr;
75  CXXInfo->EndsWithZeroSizedObject = EndsWithZeroSizedObject;
76  CXXInfo->LeadsWithZeroSizedBase = LeadsWithZeroSizedBase;
77
78#ifndef NDEBUG
79    if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
80      if (isPrimaryBaseVirtual()) {
81        if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
82          assert(getVBaseClassOffset(PrimaryBase).isZero() &&
83                 "Primary virtual base must be at offset 0!");
84        }
85      } else {
86        assert(getBaseClassOffset(PrimaryBase).isZero() &&
87               "Primary base must be at offset 0!");
88      }
89    }
90#endif
91}
92