1 files changed, 95 insertions, 0 deletions
diff --git a/lib/CodeGen/CGRecordLayout.h b/lib/CodeGen/CGRecordLayout.h
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+++ b/lib/CodeGen/CGRecordLayout.h
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+//===--- CGRecordLayout.h - LLVM Record Layout Information ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CODEGEN_CGRECORDLAYOUT_H
+#define CLANG_CODEGEN_CGRECORDLAYOUT_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "clang/AST/Decl.h"
+namespace llvm {
+  class Type;
+}
+
+namespace clang {
+namespace CodeGen {
+
+/// CGRecordLayout - This class handles struct and union layout info while
+/// lowering AST types to LLVM types.
+///
+/// These layout objects are only created on demand as IR generation requires.
+class CGRecordLayout {
+  friend class CodeGenTypes;
+
+  CGRecordLayout(const CGRecordLayout&); // DO NOT IMPLEMENT
+  void operator=(const CGRecordLayout&); // DO NOT IMPLEMENT
+
+public:
+  struct BitFieldInfo {
+    BitFieldInfo(unsigned FieldNo,
+                 unsigned Start,
+                 unsigned Size)
+      : FieldNo(FieldNo), Start(Start), Size(Size) {}
+
+    unsigned FieldNo;
+    unsigned Start;
+    unsigned Size;
+  };
+
+private:
+  /// The LLVMType corresponding to this record layout.
+  const llvm::Type *LLVMType;
+
+  /// Map from (non-bit-field) struct field to the corresponding llvm struct
+  /// type field no. This info is populated by record builder.
+  llvm::DenseMap<const FieldDecl *, unsigned> FieldInfo;
+
+  /// Map from (bit-field) struct field to the corresponding llvm struct type
+  /// field no. This info is populated by record builder.
+  llvm::DenseMap<const FieldDecl *, BitFieldInfo> BitFields;
+
+  /// 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 : 1;
+
+public:
+  CGRecordLayout(const llvm::Type *T, bool ContainsPointerToDataMember)
+    : LLVMType(T), ContainsPointerToDataMember(ContainsPointerToDataMember) {}
+
+  /// \brief Return the LLVM type associated with this record.
+  const llvm::Type *getLLVMType() const {
+    return LLVMType;
+  }
+
+  /// \brief Check whether this struct contains pointers to data members.
+  bool containsPointerToDataMember() const {
+    return ContainsPointerToDataMember;
+  }
+
+  /// \brief Return the BitFieldInfo that corresponds to the field FD.
+  unsigned getLLVMFieldNo(const FieldDecl *FD) const {
+    assert(!FD->isBitField() && "Invalid call for bit-field decl!");
+    assert(FieldInfo.count(FD) && "Invalid field for record!");
+    return FieldInfo.lookup(FD);
+  }
+
+  /// \brief Return llvm::StructType element number that corresponds to the
+  /// field FD.
+  const BitFieldInfo &getBitFieldInfo(const FieldDecl *FD) const {
+    assert(FD->isBitField() && "Invalid call for non bit-field decl!");
+    llvm::DenseMap<const FieldDecl *, BitFieldInfo>::const_iterator
+      it = BitFields.find(FD);
+    assert(it != BitFields.end()  && "Unable to find bitfield info");
+    return it->second;
+  }
+};
+
+}  // end namespace CodeGen
+}  // end namespace clang
+
+#endif