contrib/llvm-project/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 unadjustedAlignment,
  33                                  CharUnits requiredAlignment,
  34                                  CharUnits datasize,
  35                                  ArrayRef<uint64_t> fieldoffsets)
  36     : Size(size), DataSize(datasize), Alignment(alignment),
  37       UnadjustedAlignment(unadjustedAlignment),
  38       RequiredAlignment(requiredAlignment) {
  39   FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
  40 }
  41
  42 // Constructor for C++ records.
  43 ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx,
  44                                  CharUnits size, CharUnits alignment,
  45                                  CharUnits unadjustedAlignment,
  46                                  CharUnits requiredAlignment,
  47                                  bool hasOwnVFPtr, bool hasExtendableVFPtr,
  48                                  CharUnits vbptroffset,
  49                                  CharUnits datasize,
  50                                  ArrayRef<uint64_t> fieldoffsets,
  51                                  CharUnits nonvirtualsize,
  52                                  CharUnits nonvirtualalignment,
  53                                  CharUnits SizeOfLargestEmptySubobject,
  54                                  const CXXRecordDecl *PrimaryBase,
  55                                  bool IsPrimaryBaseVirtual,
  56                                  const CXXRecordDecl *BaseSharingVBPtr,
  57                                  bool EndsWithZeroSizedObject,
  58                                  bool LeadsWithZeroSizedBase,
  59                                  const BaseOffsetsMapTy& BaseOffsets,
  60                                  const VBaseOffsetsMapTy& VBaseOffsets)
  61   : Size(size), DataSize(datasize), Alignment(alignment),
  62     UnadjustedAlignment(unadjustedAlignment),
  63     RequiredAlignment(requiredAlignment), CXXInfo(new (Ctx) CXXRecordLayoutInfo)
  64 {
  65   FieldOffsets.append(Ctx, fieldoffsets.begin(), fieldoffsets.end());
  66
  67   CXXInfo->PrimaryBase.setPointer(PrimaryBase);
  68   CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
  69   CXXInfo->NonVirtualSize = nonvirtualsize;
  70   CXXInfo->NonVirtualAlignment = nonvirtualalignment;
  71   CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
  72   CXXInfo->BaseOffsets = BaseOffsets;
  73   CXXInfo->VBaseOffsets = VBaseOffsets;
  74   CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
  75   CXXInfo->VBPtrOffset = vbptroffset;
  76   CXXInfo->HasExtendableVFPtr = hasExtendableVFPtr;
  77   CXXInfo->BaseSharingVBPtr = BaseSharingVBPtr;
  78   CXXInfo->EndsWithZeroSizedObject = EndsWithZeroSizedObject;
  79   CXXInfo->LeadsWithZeroSizedBase = LeadsWithZeroSizedBase;
  80
  81 #ifndef NDEBUG
  82     if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
  83       if (isPrimaryBaseVirtual()) {
  84         if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
  85           assert(getVBaseClassOffset(PrimaryBase).isZero() &&
  86                  "Primary virtual base must be at offset 0!");
  87         }
  88       } else {
  89         assert(getBaseClassOffset(PrimaryBase).isZero() &&
  90                "Primary base must be at offset 0!");
  91       }
  92     }
  93 #endif
  94 }