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llvm-project/clang/lib/CodeGen/CGRecordLayoutBuilder.cpp

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//===--- CGRecordLayoutBuilder.cpp - CGRecordLayout builder ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Builder implementation for CGRecordLayout objects.
//
//===----------------------------------------------------------------------===//
#include "CGRecordLayout.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/Expr.h"
#include "clang/AST/RecordLayout.h"
#include "CodeGenTypes.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Type.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetData.h"
using namespace clang;
using namespace CodeGen;
namespace clang {
namespace CodeGen {
class CGRecordLayoutBuilder {
public:
/// FieldTypes - Holds the LLVM types that the struct is created from.
std::vector<const llvm::Type *> FieldTypes;
/// LLVMFieldInfo - Holds a field and its corresponding LLVM field number.
typedef std::pair<const FieldDecl *, unsigned> LLVMFieldInfo;
llvm::SmallVector<LLVMFieldInfo, 16> LLVMFields;
/// LLVMBitFieldInfo - Holds location and size information about a bit field.
typedef std::pair<const FieldDecl *, CGBitFieldInfo> LLVMBitFieldInfo;
llvm::SmallVector<LLVMBitFieldInfo, 16> LLVMBitFields;
typedef std::pair<const CXXRecordDecl *, unsigned> LLVMBaseInfo;
llvm::SmallVector<LLVMBaseInfo, 16> LLVMNonVirtualBases;
/// ContainsPointerToDataMember - Whether one of the fields in this record
/// layout is a pointer to data member, or a struct that contains pointer to
/// data member.
bool ContainsPointerToDataMember;
/// Packed - Whether the resulting LLVM struct will be packed or not.
bool Packed;
private:
CodeGenTypes &Types;
/// Alignment - Contains the alignment of the RecordDecl.
//
// FIXME: This is not needed and should be removed.
unsigned Alignment;
/// AlignmentAsLLVMStruct - Will contain the maximum alignment of all the
/// LLVM types.
unsigned AlignmentAsLLVMStruct;
/// BitsAvailableInLastField - If a bit field spans only part of a LLVM field,
/// this will have the number of bits still available in the field.
char BitsAvailableInLastField;
/// NextFieldOffsetInBytes - Holds the next field offset in bytes.
uint64_t NextFieldOffsetInBytes;
/// LayoutUnionField - Will layout a field in an union and return the type
/// that the field will have.
const llvm::Type *LayoutUnionField(const FieldDecl *Field,
const ASTRecordLayout &Layout);
/// LayoutUnion - Will layout a union RecordDecl.
void LayoutUnion(const RecordDecl *D);
/// LayoutField - try to layout all fields in the record decl.
/// Returns false if the operation failed because the struct is not packed.
bool LayoutFields(const RecordDecl *D);
/// LayoutNonVirtualBase - layout a single non-virtual base.
void LayoutNonVirtualBase(const CXXRecordDecl *BaseDecl,
uint64_t BaseOffset);
/// LayoutNonVirtualBases - layout the non-virtual bases of a record decl.
void LayoutNonVirtualBases(const CXXRecordDecl *RD,
const ASTRecordLayout &Layout);
/// LayoutField - layout a single field. Returns false if the operation failed
/// because the current struct is not packed.
bool LayoutField(const FieldDecl *D, uint64_t FieldOffset);
/// LayoutBitField - layout a single bit field.
void LayoutBitField(const FieldDecl *D, uint64_t FieldOffset);
/// AppendField - Appends a field with the given offset and type.
void AppendField(uint64_t FieldOffsetInBytes, const llvm::Type *FieldTy);
/// AppendPadding - Appends enough padding bytes so that the total
/// struct size is a multiple of the field alignment.
void AppendPadding(uint64_t FieldOffsetInBytes, unsigned FieldAlignment);
/// AppendBytes - Append a given number of bytes to the record.
void AppendBytes(uint64_t NumBytes);
/// AppendTailPadding - Append enough tail padding so that the type will have
/// the passed size.
void AppendTailPadding(uint64_t RecordSize);
unsigned getTypeAlignment(const llvm::Type *Ty) const;
/// CheckForPointerToDataMember - Check if the given type contains a pointer
/// to data member.
void CheckForPointerToDataMember(QualType T);
void CheckForPointerToDataMember(const CXXRecordDecl *RD);
public:
CGRecordLayoutBuilder(CodeGenTypes &Types)
: ContainsPointerToDataMember(false), Packed(false), Types(Types),
Alignment(0), AlignmentAsLLVMStruct(1),
BitsAvailableInLastField(0), NextFieldOffsetInBytes(0) { }
/// Layout - Will layout a RecordDecl.
void Layout(const RecordDecl *D);
};
}
}
void CGRecordLayoutBuilder::Layout(const RecordDecl *D) {
Alignment = Types.getContext().getASTRecordLayout(D).getAlignment() / 8;
Packed = D->hasAttr<PackedAttr>();
if (D->isUnion()) {
LayoutUnion(D);
return;
}
if (LayoutFields(D))
return;
// We weren't able to layout the struct. Try again with a packed struct
Packed = true;
AlignmentAsLLVMStruct = 1;
NextFieldOffsetInBytes = 0;
FieldTypes.clear();
LLVMFields.clear();
LLVMBitFields.clear();
LLVMNonVirtualBases.clear();
LayoutFields(D);
}
static CGBitFieldInfo ComputeBitFieldInfo(CodeGenTypes &Types,
const FieldDecl *FD,
uint64_t FieldOffset,
uint64_t FieldSize) {
const RecordDecl *RD = FD->getParent();
const ASTRecordLayout &RL = Types.getContext().getASTRecordLayout(RD);
uint64_t ContainingTypeSizeInBits = RL.getSize();
unsigned ContainingTypeAlign = RL.getAlignment();
const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(FD->getType());
uint64_t TypeSizeInBytes = Types.getTargetData().getTypeAllocSize(Ty);
uint64_t TypeSizeInBits = TypeSizeInBytes * 8;
bool IsSigned = FD->getType()->isSignedIntegerType();
if (FieldSize > TypeSizeInBits) {
// We have a wide bit-field. The extra bits are only used for padding, so
// if we have a bitfield of type T, with size N:
//
// T t : N;
//
// We can just assume that it's:
//
// T t : sizeof(T);
//
FieldSize = TypeSizeInBits;
}
// Compute the access components. The policy we use is to start by attempting
// to access using the width of the bit-field type itself and to always access
// at aligned indices of that type. If such an access would fail because it
// extends past the bound of the type, then we reduce size to the next smaller
// power of two and retry. The current algorithm assumes pow2 sized types,
// although this is easy to fix.
//
// FIXME: This algorithm is wrong on big-endian systems, I think.
assert(llvm::isPowerOf2_32(TypeSizeInBits) && "Unexpected type size!");
CGBitFieldInfo::AccessInfo Components[3];
unsigned NumComponents = 0;
unsigned AccessedTargetBits = 0; // The tumber of target bits accessed.
unsigned AccessWidth = TypeSizeInBits; // The current access width to attempt.
// Round down from the field offset to find the first access position that is
// at an aligned offset of the initial access type.
uint64_t AccessStart = FieldOffset - (FieldOffset % AccessWidth);
// Adjust initial access size to fit within record.
while (AccessWidth > 8 &&
AccessStart + AccessWidth > ContainingTypeSizeInBits) {
AccessWidth >>= 1;
AccessStart = FieldOffset - (FieldOffset % AccessWidth);
}
while (AccessedTargetBits < FieldSize) {
// Check that we can access using a type of this size, without reading off
// the end of the structure. This can occur with packed structures and
// -fno-bitfield-type-align, for example.
if (AccessStart + AccessWidth > ContainingTypeSizeInBits) {
// If so, reduce access size to the next smaller power-of-two and retry.
AccessWidth >>= 1;
assert(AccessWidth >= 8 && "Cannot access under byte size!");
continue;
}
// Otherwise, add an access component.
// First, compute the bits inside this access which are part of the
// target. We are reading bits [AccessStart, AccessStart + AccessWidth); the
// intersection with [FieldOffset, FieldOffset + FieldSize) gives the bits
// in the target that we are reading.
assert(FieldOffset < AccessStart + AccessWidth && "Invalid access start!");
assert(AccessStart < FieldOffset + FieldSize && "Invalid access start!");
uint64_t AccessBitsInFieldStart = std::max(AccessStart, FieldOffset);
uint64_t AccessBitsInFieldSize =
std::min(AccessWidth + AccessStart,
FieldOffset + FieldSize) - AccessBitsInFieldStart;
assert(NumComponents < 3 && "Unexpected number of components!");
CGBitFieldInfo::AccessInfo &AI = Components[NumComponents++];
AI.FieldIndex = 0;
// FIXME: We still follow the old access pattern of only using the field
// byte offset. We should switch this once we fix the struct layout to be
// pretty.
AI.FieldByteOffset = AccessStart / 8;
AI.FieldBitStart = AccessBitsInFieldStart - AccessStart;
AI.AccessWidth = AccessWidth;
AI.AccessAlignment = llvm::MinAlign(ContainingTypeAlign, AccessStart) / 8;
AI.TargetBitOffset = AccessedTargetBits;
AI.TargetBitWidth = AccessBitsInFieldSize;
AccessStart += AccessWidth;
AccessedTargetBits += AI.TargetBitWidth;
}
assert(AccessedTargetBits == FieldSize && "Invalid bit-field access!");
return CGBitFieldInfo(FieldSize, NumComponents, Components, IsSigned);
}
void CGRecordLayoutBuilder::LayoutBitField(const FieldDecl *D,
uint64_t FieldOffset) {
uint64_t FieldSize =
D->getBitWidth()->EvaluateAsInt(Types.getContext()).getZExtValue();
if (FieldSize == 0)
return;
uint64_t NextFieldOffset = NextFieldOffsetInBytes * 8;
unsigned NumBytesToAppend;
if (FieldOffset < NextFieldOffset) {
assert(BitsAvailableInLastField && "Bitfield size mismatch!");
assert(NextFieldOffsetInBytes && "Must have laid out at least one byte!");
// The bitfield begins in the previous bit-field.
NumBytesToAppend =
llvm::RoundUpToAlignment(FieldSize - BitsAvailableInLastField, 8) / 8;
} else {
assert(FieldOffset % 8 == 0 && "Field offset not aligned correctly");
// Append padding if necessary.
AppendBytes((FieldOffset - NextFieldOffset) / 8);
NumBytesToAppend =
llvm::RoundUpToAlignment(FieldSize, 8) / 8;
assert(NumBytesToAppend && "No bytes to append!");
}
// Add the bit field info.
LLVMBitFields.push_back(
LLVMBitFieldInfo(D, ComputeBitFieldInfo(Types, D, FieldOffset, FieldSize)));
AppendBytes(NumBytesToAppend);
BitsAvailableInLastField =
NextFieldOffsetInBytes * 8 - (FieldOffset + FieldSize);
}
bool CGRecordLayoutBuilder::LayoutField(const FieldDecl *D,
uint64_t FieldOffset) {
// If the field is packed, then we need a packed struct.
if (!Packed && D->hasAttr<PackedAttr>())
return false;
if (D->isBitField()) {
// We must use packed structs for unnamed bit fields since they
// don't affect the struct alignment.
if (!Packed && !D->getDeclName())
return false;
LayoutBitField(D, FieldOffset);
return true;
}
// Check if we have a pointer to data member in this field.
CheckForPointerToDataMember(D->getType());
assert(FieldOffset % 8 == 0 && "FieldOffset is not on a byte boundary!");
uint64_t FieldOffsetInBytes = FieldOffset / 8;
const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(D->getType());
unsigned TypeAlignment = getTypeAlignment(Ty);
// If the type alignment is larger then the struct alignment, we must use
// a packed struct.
if (TypeAlignment > Alignment) {
assert(!Packed && "Alignment is wrong even with packed struct!");
return false;
}
if (const RecordType *RT = D->getType()->getAs<RecordType>()) {
const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
if (const MaxFieldAlignmentAttr *MFAA =
RD->getAttr<MaxFieldAlignmentAttr>()) {
if (MFAA->getAlignment() != TypeAlignment * 8 && !Packed)
return false;
}
}
// Round up the field offset to the alignment of the field type.
uint64_t AlignedNextFieldOffsetInBytes =
llvm::RoundUpToAlignment(NextFieldOffsetInBytes, TypeAlignment);
if (FieldOffsetInBytes < AlignedNextFieldOffsetInBytes) {
assert(!Packed && "Could not place field even with packed struct!");
return false;
}
if (AlignedNextFieldOffsetInBytes < FieldOffsetInBytes) {
// Even with alignment, the field offset is not at the right place,
// insert padding.
uint64_t PaddingInBytes = FieldOffsetInBytes - NextFieldOffsetInBytes;
AppendBytes(PaddingInBytes);
}
// Now append the field.
LLVMFields.push_back(LLVMFieldInfo(D, FieldTypes.size()));
AppendField(FieldOffsetInBytes, Ty);
return true;
}
const llvm::Type *
CGRecordLayoutBuilder::LayoutUnionField(const FieldDecl *Field,
const ASTRecordLayout &Layout) {
if (Field->isBitField()) {
uint64_t FieldSize =
Field->getBitWidth()->EvaluateAsInt(Types.getContext()).getZExtValue();
// Ignore zero sized bit fields.
if (FieldSize == 0)
return 0;
const llvm::Type *FieldTy = llvm::Type::getInt8Ty(Types.getLLVMContext());
unsigned NumBytesToAppend =
llvm::RoundUpToAlignment(FieldSize, 8) / 8;
if (NumBytesToAppend > 1)
FieldTy = llvm::ArrayType::get(FieldTy, NumBytesToAppend);
// Add the bit field info.
LLVMBitFields.push_back(
LLVMBitFieldInfo(Field, ComputeBitFieldInfo(Types, Field, 0, FieldSize)));
return FieldTy;
}
// This is a regular union field.
LLVMFields.push_back(LLVMFieldInfo(Field, 0));
return Types.ConvertTypeForMemRecursive(Field->getType());
}
void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
assert(D->isUnion() && "Can't call LayoutUnion on a non-union record!");
const ASTRecordLayout &Layout = Types.getContext().getASTRecordLayout(D);
const llvm::Type *Ty = 0;
uint64_t Size = 0;
unsigned Align = 0;
bool HasOnlyZeroSizedBitFields = true;
unsigned FieldNo = 0;
for (RecordDecl::field_iterator Field = D->field_begin(),
FieldEnd = D->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
assert(Layout.getFieldOffset(FieldNo) == 0 &&
"Union field offset did not start at the beginning of record!");
const llvm::Type *FieldTy = LayoutUnionField(*Field, Layout);
if (!FieldTy)
continue;
HasOnlyZeroSizedBitFields = false;
unsigned FieldAlign = Types.getTargetData().getABITypeAlignment(FieldTy);
uint64_t FieldSize = Types.getTargetData().getTypeAllocSize(FieldTy);
if (FieldAlign < Align)
continue;
if (FieldAlign > Align || FieldSize > Size) {
Ty = FieldTy;
Align = FieldAlign;
Size = FieldSize;
}
}
// Now add our field.
if (Ty) {
AppendField(0, Ty);
if (getTypeAlignment(Ty) > Layout.getAlignment() / 8) {
// We need a packed struct.
Packed = true;
Align = 1;
}
}
if (!Align) {
assert(HasOnlyZeroSizedBitFields &&
"0-align record did not have all zero-sized bit-fields!");
Align = 1;
}
// Append tail padding.
if (Layout.getSize() / 8 > Size)
AppendPadding(Layout.getSize() / 8, Align);
}
void CGRecordLayoutBuilder::LayoutNonVirtualBase(const CXXRecordDecl *BaseDecl,
uint64_t BaseOffset) {
const ASTRecordLayout &Layout =
Types.getContext().getASTRecordLayout(BaseDecl);
uint64_t NonVirtualSize = Layout.getNonVirtualSize();
if (BaseDecl->isEmpty()) {
// FIXME: Lay out empty bases.
return;
}
CheckForPointerToDataMember(BaseDecl);
// FIXME: Actually use a better type than [sizeof(BaseDecl) x i8] when we can.
AppendPadding(BaseOffset / 8, 1);
// Append the base field.
LLVMNonVirtualBases.push_back(LLVMBaseInfo(BaseDecl, FieldTypes.size()));
AppendBytes(NonVirtualSize / 8);
}
void
CGRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD,
const ASTRecordLayout &Layout) {
const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
// Check if we need to add a vtable pointer.
if (RD->isDynamicClass()) {
if (!PrimaryBase) {
const llvm::Type *FunctionType =
llvm::FunctionType::get(llvm::Type::getInt32Ty(Types.getLLVMContext()),
/*isVarArg=*/true);
const llvm::Type *VTableTy = FunctionType->getPointerTo();
assert(NextFieldOffsetInBytes == 0 &&
"VTable pointer must come first!");
AppendField(NextFieldOffsetInBytes, VTableTy->getPointerTo());
} else {
// FIXME: Handle a virtual primary base.
if (!Layout.getPrimaryBaseWasVirtual())
LayoutNonVirtualBase(PrimaryBase, 0);
}
}
// Layout the non-virtual bases.
for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
E = RD->bases_end(); I != E; ++I) {
if (I->isVirtual())
continue;
const CXXRecordDecl *BaseDecl =
cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
// We've already laid out the primary base.
if (BaseDecl == PrimaryBase && !Layout.getPrimaryBaseWasVirtual())
continue;
LayoutNonVirtualBase(BaseDecl, Layout.getBaseClassOffset(BaseDecl));
}
}
bool CGRecordLayoutBuilder::LayoutFields(const RecordDecl *D) {
assert(!D->isUnion() && "Can't call LayoutFields on a union!");
assert(Alignment && "Did not set alignment!");
const ASTRecordLayout &Layout = Types.getContext().getASTRecordLayout(D);
if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
LayoutNonVirtualBases(RD, Layout);
unsigned FieldNo = 0;
for (RecordDecl::field_iterator Field = D->field_begin(),
FieldEnd = D->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
if (!LayoutField(*Field, Layout.getFieldOffset(FieldNo))) {
assert(!Packed &&
"Could not layout fields even with a packed LLVM struct!");
return false;
}
}
// Append tail padding if necessary.
AppendTailPadding(Layout.getSize());
return true;
}
void CGRecordLayoutBuilder::AppendTailPadding(uint64_t RecordSize) {
assert(RecordSize % 8 == 0 && "Invalid record size!");
uint64_t RecordSizeInBytes = RecordSize / 8;
assert(NextFieldOffsetInBytes <= RecordSizeInBytes && "Size mismatch!");
uint64_t AlignedNextFieldOffset =
llvm::RoundUpToAlignment(NextFieldOffsetInBytes, AlignmentAsLLVMStruct);
if (AlignedNextFieldOffset == RecordSizeInBytes) {
// We don't need any padding.
return;
}
unsigned NumPadBytes = RecordSizeInBytes - NextFieldOffsetInBytes;
AppendBytes(NumPadBytes);
}
void CGRecordLayoutBuilder::AppendField(uint64_t FieldOffsetInBytes,
const llvm::Type *FieldTy) {
AlignmentAsLLVMStruct = std::max(AlignmentAsLLVMStruct,
getTypeAlignment(FieldTy));
uint64_t FieldSizeInBytes = Types.getTargetData().getTypeAllocSize(FieldTy);
FieldTypes.push_back(FieldTy);
NextFieldOffsetInBytes = FieldOffsetInBytes + FieldSizeInBytes;
BitsAvailableInLastField = 0;
}
void CGRecordLayoutBuilder::AppendPadding(uint64_t FieldOffsetInBytes,
unsigned FieldAlignment) {
assert(NextFieldOffsetInBytes <= FieldOffsetInBytes &&
"Incorrect field layout!");
// Round up the field offset to the alignment of the field type.
uint64_t AlignedNextFieldOffsetInBytes =
llvm::RoundUpToAlignment(NextFieldOffsetInBytes, FieldAlignment);
if (AlignedNextFieldOffsetInBytes < FieldOffsetInBytes) {
// Even with alignment, the field offset is not at the right place,
// insert padding.
uint64_t PaddingInBytes = FieldOffsetInBytes - NextFieldOffsetInBytes;
AppendBytes(PaddingInBytes);
}
}
void CGRecordLayoutBuilder::AppendBytes(uint64_t NumBytes) {
if (NumBytes == 0)
return;
const llvm::Type *Ty = llvm::Type::getInt8Ty(Types.getLLVMContext());
if (NumBytes > 1)
Ty = llvm::ArrayType::get(Ty, NumBytes);
// Append the padding field
AppendField(NextFieldOffsetInBytes, Ty);
}
unsigned CGRecordLayoutBuilder::getTypeAlignment(const llvm::Type *Ty) const {
if (Packed)
return 1;
return Types.getTargetData().getABITypeAlignment(Ty);
}
void CGRecordLayoutBuilder::CheckForPointerToDataMember(QualType T) {
// This record already contains a member pointer.
if (ContainsPointerToDataMember)
return;
// Can only have member pointers if we're compiling C++.
if (!Types.getContext().getLangOptions().CPlusPlus)
return;
T = Types.getContext().getBaseElementType(T);
if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) {
if (!MPT->getPointeeType()->isFunctionType()) {
// We have a pointer to data member.
ContainsPointerToDataMember = true;
}
} else if (const RecordType *RT = T->getAs<RecordType>()) {
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
return CheckForPointerToDataMember(RD);
}
}
void
CGRecordLayoutBuilder::CheckForPointerToDataMember(const CXXRecordDecl *RD) {
// This record already contains a member pointer.
if (ContainsPointerToDataMember)
return;
// FIXME: It would be better if there was a way to explicitly compute the
// record layout instead of converting to a type.
Types.ConvertTagDeclType(RD);
const CGRecordLayout &Layout = Types.getCGRecordLayout(RD);
if (Layout.containsPointerToDataMember())
ContainsPointerToDataMember = true;
}
CGRecordLayout *CodeGenTypes::ComputeRecordLayout(const RecordDecl *D) {
CGRecordLayoutBuilder Builder(*this);
Builder.Layout(D);
const llvm::Type *Ty = llvm::StructType::get(getLLVMContext(),
Builder.FieldTypes,
Builder.Packed);
CGRecordLayout *RL =
new CGRecordLayout(Ty, Builder.ContainsPointerToDataMember);
// Add all the non-virtual base field numbers.
RL->NonVirtualBaseFields.insert(Builder.LLVMNonVirtualBases.begin(),
Builder.LLVMNonVirtualBases.end());
// Add all the field numbers.
RL->FieldInfo.insert(Builder.LLVMFields.begin(),
Builder.LLVMFields.end());
// Add bitfield info.
RL->BitFields.insert(Builder.LLVMBitFields.begin(),
Builder.LLVMBitFields.end());
// Dump the layout, if requested.
if (getContext().getLangOptions().DumpRecordLayouts) {
llvm::errs() << "\n*** Dumping IRgen Record Layout\n";
llvm::errs() << "Record: ";
D->dump();
llvm::errs() << "\nLayout: ";
RL->dump();
}
#ifndef NDEBUG
// Verify that the computed LLVM struct size matches the AST layout size.
uint64_t TypeSizeInBits = getContext().getASTRecordLayout(D).getSize();
assert(TypeSizeInBits == getTargetData().getTypeAllocSizeInBits(Ty) &&
"Type size mismatch!");
// Verify that the LLVM and AST field offsets agree.
const llvm::StructType *ST =
dyn_cast<llvm::StructType>(RL->getLLVMType());
const llvm::StructLayout *SL = getTargetData().getStructLayout(ST);
const ASTRecordLayout &AST_RL = getContext().getASTRecordLayout(D);
RecordDecl::field_iterator it = D->field_begin();
for (unsigned i = 0, e = AST_RL.getFieldCount(); i != e; ++i, ++it) {
const FieldDecl *FD = *it;
// For non-bit-fields, just check that the LLVM struct offset matches the
// AST offset.
if (!FD->isBitField()) {
unsigned FieldNo = RL->getLLVMFieldNo(FD);
assert(AST_RL.getFieldOffset(i) == SL->getElementOffsetInBits(FieldNo) &&
"Invalid field offset!");
continue;
}
// Ignore unnamed bit-fields.
if (!FD->getDeclName())
continue;
const CGBitFieldInfo &Info = RL->getBitFieldInfo(FD);
for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
// Verify that every component access is within the structure.
uint64_t FieldOffset = SL->getElementOffsetInBits(AI.FieldIndex);
uint64_t AccessBitOffset = FieldOffset + AI.FieldByteOffset * 8;
assert(AccessBitOffset + AI.AccessWidth <= TypeSizeInBits &&
"Invalid bit-field access (out of range)!");
}
}
#endif
return RL;
}
void CGRecordLayout::print(llvm::raw_ostream &OS) const {
OS << "<CGRecordLayout\n";
OS << " LLVMType:" << *LLVMType << "\n";
OS << " ContainsPointerToDataMember:" << ContainsPointerToDataMember << "\n";
OS << " BitFields:[\n";
// Print bit-field infos in declaration order.
std::vector<std::pair<unsigned, const CGBitFieldInfo*> > BFIs;
for (llvm::DenseMap<const FieldDecl*, CGBitFieldInfo>::const_iterator
it = BitFields.begin(), ie = BitFields.end();
it != ie; ++it) {
const RecordDecl *RD = it->first->getParent();
unsigned Index = 0;
for (RecordDecl::field_iterator
it2 = RD->field_begin(); *it2 != it->first; ++it2)
++Index;
BFIs.push_back(std::make_pair(Index, &it->second));
}
llvm::array_pod_sort(BFIs.begin(), BFIs.end());
for (unsigned i = 0, e = BFIs.size(); i != e; ++i) {
OS.indent(4);
BFIs[i].second->print(OS);
OS << "\n";
}
OS << "]>\n";
}
void CGRecordLayout::dump() const {
print(llvm::errs());
}
void CGBitFieldInfo::print(llvm::raw_ostream &OS) const {
OS << "<CGBitFieldInfo";
OS << " Size:" << Size;
OS << " IsSigned:" << IsSigned << "\n";
OS.indent(4 + strlen("<CGBitFieldInfo"));
OS << " NumComponents:" << getNumComponents();
OS << " Components: [";
if (getNumComponents()) {
OS << "\n";
for (unsigned i = 0, e = getNumComponents(); i != e; ++i) {
const AccessInfo &AI = getComponent(i);
OS.indent(8);
OS << "<AccessInfo"
<< " FieldIndex:" << AI.FieldIndex
<< " FieldByteOffset:" << AI.FieldByteOffset
<< " FieldBitStart:" << AI.FieldBitStart
<< " AccessWidth:" << AI.AccessWidth << "\n";
OS.indent(8 + strlen("<AccessInfo"));
OS << " AccessAlignment:" << AI.AccessAlignment
<< " TargetBitOffset:" << AI.TargetBitOffset
<< " TargetBitWidth:" << AI.TargetBitWidth
<< ">\n";
}
OS.indent(4);
}
OS << "]>";
}
void CGBitFieldInfo::dump() const {
print(llvm::errs());
}
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