Subzero: Add basic ELFObjectWriter (text section, symtab, strtab, headers)

src/IceMemoryRegion.h

-//===- subzero/src/IceMemoryRegion.h - Memory region ------------*- C++ -*-===//
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-//
-// Modified by the Subzero authors.
-//
-//===----------------------------------------------------------------------===//
-//
-//                        The Subzero Code Generator
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file declares the MemoryRegion class. It tracks a pointer
-// plus its bounds for bounds-checking in debug mode.
-//===----------------------------------------------------------------------===//
-
-#ifndef SUBZERO_SRC_ICE_MEMORY_REGION_H_
-#define SUBZERO_SRC_ICE_MEMORY_REGION_H_
-
-#include "IceDefs.h"
-#include "IceUtils.h"
-
-namespace Ice {
-
-// Memory regions are useful for accessing memory with bounds check in
-// debug mode. They can be safely passed by value and do not assume ownership
-// of the region.
-class MemoryRegion {
-public:
-  MemoryRegion(const MemoryRegion &other) = default;
-  MemoryRegion &operator=(const MemoryRegion &other) = default;
-  MemoryRegion() : pointer_(NULL), size_(0) {}
-  MemoryRegion(void *pointer, size_t size) : pointer_(pointer), size_(size) {}
-
-  void *pointer() const { return pointer_; }
-  size_t size() const { return size_; }
-
-  size_t start() const { return reinterpret_cast<size_t>(pointer_); }
-  size_t end() const { return start() + size_; }
-
-  template <typename T> T Load(size_t offset) const {
-    return *ComputeInternalPointer<T>(offset);
-  }
-
-  template <typename T> void Store(size_t offset, T value) const {
-    *ComputeInternalPointer<T>(offset) = value;
-  }
-
-  template <typename T> T *PointerTo(size_t offset) const {
-    return ComputeInternalPointer<T>(offset);
-  }
-
-  bool Contains(size_t address) const {
-    return (address >= start()) && (address < end());
-  }
-
-  void CopyFrom(size_t offset, const MemoryRegion &from) const;
-
-  // Compute a sub memory region based on an existing one.
-  void Subregion(const MemoryRegion &from, size_t offset, size_t size) {
-    assert(from.size() >= size);
-    assert(offset <= (from.size() - size));
-    pointer_ = reinterpret_cast<void *>(from.start() + offset);
-    size_ = size;
-  }
-
-  // Compute an extended memory region based on an existing one.
-  void Extend(const MemoryRegion &region, size_t extra) {
-    pointer_ = region.pointer();
-    size_ = (region.size() + extra);
-  }
-
-private:
-  template <typename T> T *ComputeInternalPointer(size_t offset) const {
-    assert(size() >= sizeof(T));
-    assert(offset <= size() - sizeof(T));
-    return reinterpret_cast<T *>(start() + offset);
-  }
-
-  void *pointer_;
-  size_t size_;
-};
-
-} // end of namespace Ice
-
-#endif // SUBZERO_SRC_ICE_MEMORY_REGION_H_