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
19 using namespace clang;
20
Destroy(ASTContext & Ctx)21 void ASTRecordLayout::Destroy(ASTContext &Ctx) {
22 if (CXXInfo) {
23 CXXInfo->~CXXRecordLayoutInfo();
24 Ctx.Deallocate(CXXInfo);
25 }
26 this->~ASTRecordLayout();
27 Ctx.Deallocate(this);
28 }
29
ASTRecordLayout(const ASTContext & Ctx,CharUnits size,CharUnits alignment,CharUnits preferredAlignment,CharUnits unadjustedAlignment,CharUnits requiredAlignment,CharUnits datasize,ArrayRef<uint64_t> fieldoffsets)30 ASTRecordLayout::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.
ASTRecordLayout(const ASTContext & Ctx,CharUnits size,CharUnits alignment,CharUnits preferredAlignment,CharUnits unadjustedAlignment,CharUnits requiredAlignment,bool hasOwnVFPtr,bool hasExtendableVFPtr,CharUnits vbptroffset,CharUnits datasize,ArrayRef<uint64_t> fieldoffsets,CharUnits nonvirtualsize,CharUnits nonvirtualalignment,CharUnits preferrednvalignment,CharUnits SizeOfLargestEmptySubobject,const CXXRecordDecl * PrimaryBase,bool IsPrimaryBaseVirtual,const CXXRecordDecl * BaseSharingVBPtr,bool EndsWithZeroSizedObject,bool LeadsWithZeroSizedBase,const BaseOffsetsMapTy & BaseOffsets,const VBaseOffsetsMapTy & VBaseOffsets)45 ASTRecordLayout::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