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1 //===-- RecordLayout.cpp - Layout information for a struct/union -*- C++ -*-==//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file defines the RecordLayout interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/RecordLayout.h"
16 #include "clang/Basic/TargetInfo.h"
17 
18 using namespace clang;
19 
Destroy(ASTContext & Ctx)20 void ASTRecordLayout::Destroy(ASTContext &Ctx) {
21   if (CXXInfo) {
22     CXXInfo->~CXXRecordLayoutInfo();
23     Ctx.Deallocate(CXXInfo);
24   }
25   this->~ASTRecordLayout();
26   Ctx.Deallocate(this);
27 }
28 
ASTRecordLayout(const ASTContext & Ctx,CharUnits size,CharUnits alignment,CharUnits requiredAlignment,CharUnits datasize,ArrayRef<uint64_t> fieldoffsets)29 ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx, CharUnits size,
30                                  CharUnits alignment,
31                                  CharUnits requiredAlignment,
32                                  CharUnits datasize,
33                                  ArrayRef<uint64_t> fieldoffsets)
34     : Size(size), DataSize(datasize), Alignment(alignment),
35       RequiredAlignment(requiredAlignment), CXXInfo(nullptr) {
36   FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
37 }
38 
39 // Constructor for C++ records.
ASTRecordLayout(const ASTContext & Ctx,CharUnits size,CharUnits alignment,CharUnits requiredAlignment,bool hasOwnVFPtr,bool hasExtendableVFPtr,CharUnits vbptroffset,CharUnits datasize,ArrayRef<uint64_t> fieldoffsets,CharUnits nonvirtualsize,CharUnits nonvirtualalignment,CharUnits SizeOfLargestEmptySubobject,const CXXRecordDecl * PrimaryBase,bool IsPrimaryBaseVirtual,const CXXRecordDecl * BaseSharingVBPtr,bool EndsWithZeroSizedObject,bool LeadsWithZeroSizedBase,const BaseOffsetsMapTy & BaseOffsets,const VBaseOffsetsMapTy & VBaseOffsets)40 ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx,
41                                  CharUnits size, CharUnits alignment,
42                                  CharUnits requiredAlignment,
43                                  bool hasOwnVFPtr, bool hasExtendableVFPtr,
44                                  CharUnits vbptroffset,
45                                  CharUnits datasize,
46                                  ArrayRef<uint64_t> fieldoffsets,
47                                  CharUnits nonvirtualsize,
48                                  CharUnits nonvirtualalignment,
49                                  CharUnits SizeOfLargestEmptySubobject,
50                                  const CXXRecordDecl *PrimaryBase,
51                                  bool IsPrimaryBaseVirtual,
52                                  const CXXRecordDecl *BaseSharingVBPtr,
53                                  bool EndsWithZeroSizedObject,
54                                  bool LeadsWithZeroSizedBase,
55                                  const BaseOffsetsMapTy& BaseOffsets,
56                                  const VBaseOffsetsMapTy& VBaseOffsets)
57   : Size(size), DataSize(datasize), Alignment(alignment),
58     RequiredAlignment(requiredAlignment), CXXInfo(new (Ctx) CXXRecordLayoutInfo)
59 {
60   FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
61 
62   CXXInfo->PrimaryBase.setPointer(PrimaryBase);
63   CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
64   CXXInfo->NonVirtualSize = nonvirtualsize;
65   CXXInfo->NonVirtualAlignment = nonvirtualalignment;
66   CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
67   CXXInfo->BaseOffsets = BaseOffsets;
68   CXXInfo->VBaseOffsets = VBaseOffsets;
69   CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
70   CXXInfo->VBPtrOffset = vbptroffset;
71   CXXInfo->HasExtendableVFPtr = hasExtendableVFPtr;
72   CXXInfo->BaseSharingVBPtr = BaseSharingVBPtr;
73   CXXInfo->EndsWithZeroSizedObject = EndsWithZeroSizedObject;
74   CXXInfo->LeadsWithZeroSizedBase = LeadsWithZeroSizedBase;
75 
76 
77 #ifndef NDEBUG
78     if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
79       if (isPrimaryBaseVirtual()) {
80         if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
81           assert(getVBaseClassOffset(PrimaryBase).isZero() &&
82                  "Primary virtual base must be at offset 0!");
83         }
84       } else {
85         assert(getBaseClassOffset(PrimaryBase).isZero() &&
86                "Primary base must be at offset 0!");
87       }
88     }
89 #endif
90 }
91