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 
20 void ASTRecordLayout::Destroy(ASTContext &Ctx) {
21   if (FieldOffsets)
22     Ctx.Deallocate(FieldOffsets);
23   if (CXXInfo) {
24     Ctx.Deallocate(CXXInfo);
25     CXXInfo->~CXXRecordLayoutInfo();
26   }
27   this->~ASTRecordLayout();
28   Ctx.Deallocate(this);
29 }
30 
31 ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx, CharUnits size,
32                                  CharUnits alignment,
33                                  CharUnits requiredAlignment,
34                                  CharUnits datasize,
35                                  const uint64_t *fieldoffsets,
36                                  unsigned fieldcount)
37   : Size(size), DataSize(datasize), Alignment(alignment),
38     RequiredAlignment(requiredAlignment), FieldOffsets(0),
39     FieldCount(fieldcount), CXXInfo(0) {
40   if (FieldCount > 0)  {
41     FieldOffsets = new (Ctx) uint64_t[FieldCount];
42     memcpy(FieldOffsets, fieldoffsets, FieldCount * sizeof(*FieldOffsets));
43   }
44 }
45 
46 // Constructor for C++ records.
47 ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx,
48                                  CharUnits size, CharUnits alignment,
49                                  CharUnits requiredAlignment,
50                                  bool hasOwnVFPtr, bool hasExtendableVFPtr,
51                                  CharUnits vbptroffset,
52                                  CharUnits datasize,
53                                  const uint64_t *fieldoffsets,
54                                  unsigned fieldcount,
55                                  CharUnits nonvirtualsize,
56                                  CharUnits nonvirtualalign,
57                                  CharUnits SizeOfLargestEmptySubobject,
58                                  const CXXRecordDecl *PrimaryBase,
59                                  bool IsPrimaryBaseVirtual,
60                                  const CXXRecordDecl *BaseSharingVBPtr,
61                                  const BaseOffsetsMapTy& BaseOffsets,
62                                  const VBaseOffsetsMapTy& VBaseOffsets)
63   : Size(size), DataSize(datasize), Alignment(alignment),
64     RequiredAlignment(requiredAlignment), FieldOffsets(0),
65     FieldCount(fieldcount), CXXInfo(new (Ctx) CXXRecordLayoutInfo)
66 {
67   if (FieldCount > 0)  {
68     FieldOffsets = new (Ctx) uint64_t[FieldCount];
69     memcpy(FieldOffsets, fieldoffsets, FieldCount * sizeof(*FieldOffsets));
70   }
71 
72   CXXInfo->PrimaryBase.setPointer(PrimaryBase);
73   CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
74   CXXInfo->NonVirtualSize = nonvirtualsize;
75   CXXInfo->NonVirtualAlign = nonvirtualalign;
76   CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
77   CXXInfo->BaseOffsets = BaseOffsets;
78   CXXInfo->VBaseOffsets = VBaseOffsets;
79   CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
80   CXXInfo->VBPtrOffset = vbptroffset;
81   CXXInfo->HasExtendableVFPtr = hasExtendableVFPtr;
82   CXXInfo->BaseSharingVBPtr = BaseSharingVBPtr;
83 
84 
85 #ifndef NDEBUG
86     if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
87       if (isPrimaryBaseVirtual()) {
88         if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
89           assert(getVBaseClassOffset(PrimaryBase).isZero() &&
90                  "Primary virtual base must be at offset 0!");
91         }
92       } else {
93         assert(getBaseClassOffset(PrimaryBase).isZero() &&
94                "Primary base must be at offset 0!");
95       }
96     }
97 #endif
98 }
99