contrib/llvm/tools/clang/lib/AST/RecordLayout.cpp

   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()) {
  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 }