clang  3.9.0
RecordLayout.cpp
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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 
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 
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.
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()) {
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 }
Defines the clang::ASTContext interface.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:92
void Deallocate(void *Ptr) const
Definition: ASTContext.h:574
bool hasPrimaryVBases() const
Does this ABI allow virtual bases to be primary base classes?
Definition: TargetCXXABI.h:228
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:588
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:34
Represents a C++ struct/union/class.
Definition: DeclCXX.h:263
TargetCXXABI getCXXABI() const
Get the C++ ABI currently in use.
Defines the clang::TargetInfo interface.