clang/lib/AST/RecordLayout.cpp

   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
  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
  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.
  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 }