Update clang to r84119.

1 files changed, 386 insertions, 0 deletions

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
new file mode 100644
index 0000000..7baf69d
--- /dev/null
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -0,0 +1,386 @@
+//===--- CGRecordLayoutBuilder.cpp - Record builder helper ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a helper class used to build CGRecordLayout objects and LLVM types.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGRecordLayoutBuilder.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/Target/TargetData.h"
+
+
+using namespace clang;
+using namespace CodeGen;
+
+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();
+
+  LayoutFields(D);
+}
+
+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!");
+  }
+
+  const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(D->getType());
+  uint64_t TypeSizeInBits = getTypeSizeInBytes(Ty) * 8;
+
+  LLVMBitFields.push_back(LLVMBitFieldInfo(D, FieldOffset / TypeSizeInBits,
+                                           FieldOffset % TypeSizeInBits,
+                                           FieldSize));
+
+  AppendBytes(NumBytesToAppend);
+
+  AlignmentAsLLVMStruct = std::max(AlignmentAsLLVMStruct, getTypeAlignment(Ty));
+
+  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;
+  }
+
+  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 PragmaPackAttr *PPA = RD->getAttr<PragmaPackAttr>()) {
+      if (PPA->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;
+}
+
+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;
+
+  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!");
+
+    if (Field->isBitField()) {
+      uint64_t FieldSize =
+        Field->getBitWidth()->EvaluateAsInt(Types.getContext()).getZExtValue();
+
+      // Ignore zero sized bit fields.
+      if (FieldSize == 0)
+        continue;
+
+      // Add the bit field info.
+      Types.addBitFieldInfo(*Field, 0, 0, FieldSize);
+    } else
+      Types.addFieldInfo(*Field, 0);
+
+    const llvm::Type *FieldTy =
+      Types.ConvertTypeForMemRecursive(Field->getType());
+    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;
+    }
+  }
+
+  // Append tail padding.
+  if (Layout.getSize() / 8 > Size)
+    AppendPadding(Layout.getSize() / 8, Align);
+}
+
+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);
+
+  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!");
+
+  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 = getTypeSizeInBytes(FieldTy);
+
+  FieldTypes.push_back(FieldTy);
+
+  NextFieldOffsetInBytes = FieldOffsetInBytes + FieldSizeInBytes;
+  BitsAvailableInLastField = 0;
+}
+
+void
+CGRecordLayoutBuilder::AppendPadding(uint64_t FieldOffsetInBytes,
+                                     const llvm::Type *FieldTy) {
+  AppendPadding(FieldOffsetInBytes, getTypeAlignment(FieldTy));
+}
+
+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);
+}
+
+uint64_t CGRecordLayoutBuilder::getTypeSizeInBytes(const llvm::Type *Ty) const {
+  return Types.getTargetData().getTypeAllocSize(Ty);
+}
+
+void CGRecordLayoutBuilder::CheckForMemberPointer(const FieldDecl *FD) {
+  // This record already contains a member pointer.
+  if (ContainsMemberPointer)
+    return;
+
+  // Can only have member pointers if we're compiling C++.
+  if (!Types.getContext().getLangOptions().CPlusPlus)
+    return;
+
+  QualType Ty = FD->getType();
+
+  if (Ty->isMemberPointerType()) {
+    // We have a member pointer!
+    ContainsMemberPointer = true;
+    return;
+  }
+
+}
+
+static const CXXMethodDecl *GetKeyFunction(const RecordDecl *D) {
+  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D);
+  if (!RD || !RD->isDynamicClass())
+    return 0;
+  
+  for (CXXRecordDecl::method_iterator I = RD->method_begin(), 
+       E = RD->method_end(); I != E; ++I) {
+    const CXXMethodDecl *MD = *I;
+    
+    if (!MD->isVirtual())
+      continue;
+    
+    if (MD->isPure())
+      continue;
+
+    if (MD->getBody())
+      continue;
+
+    // We found it.
+    return MD;
+  }
+  
+  return 0;
+}
+
+CGRecordLayout *
+CGRecordLayoutBuilder::ComputeLayout(CodeGenTypes &Types,
+                                     const RecordDecl *D) {
+  CGRecordLayoutBuilder Builder(Types);
+
+  Builder.Layout(D);
+
+  const llvm::Type *Ty = llvm::StructType::get(Types.getLLVMContext(),
+                                               Builder.FieldTypes,
+                                               Builder.Packed);
+  assert(Types.getContext().getASTRecordLayout(D).getSize() / 8 ==
+         Types.getTargetData().getTypeAllocSize(Ty) &&
+         "Type size mismatch!");
+
+  // Add all the field numbers.
+  for (unsigned i = 0, e = Builder.LLVMFields.size(); i != e; ++i) {
+    const FieldDecl *FD = Builder.LLVMFields[i].first;
+    unsigned FieldNo = Builder.LLVMFields[i].second;
+
+    Types.addFieldInfo(FD, FieldNo);
+  }
+
+  // Add bitfield info.
+  for (unsigned i = 0, e = Builder.LLVMBitFields.size(); i != e; ++i) {
+    const LLVMBitFieldInfo &Info = Builder.LLVMBitFields[i];
+
+    Types.addBitFieldInfo(Info.FD, Info.FieldNo, Info.Start, Info.Size);
+  }
+
+  const CXXMethodDecl *KeyFunction = GetKeyFunction(D);
+
+  return new CGRecordLayout(Ty, Builder.ContainsMemberPointer, KeyFunction);
+}