Subzero: Fix build problem against LLVM trunk.

pnacl-llvm/include/llvm/Support/MemoryObject.h

+//===- MemoryObject.h - Abstract memory interface ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_MEMORYOBJECT_H
+#define LLVM_SUPPORT_MEMORYOBJECT_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+/// Interface to data which might be streamed. Streamability has 2 important
+/// implications/restrictions. First, the data might not yet exist in memory
+/// when the request is made. This just means that readByte/readBytes might have
+/// to block or do some work to get it. More significantly, the exact size of
+/// the object might not be known until it has all been fetched. This means that
+/// to return the right result, getExtent must also wait for all the data to
+/// arrive; therefore it should not be called on objects which are actually
+/// streamed (this would defeat the purpose of streaming). Instead,
+/// isValidAddress can be used to test addresses without knowing the exact size
+/// of the stream. Finally, getPointer can be used instead of readBytes to avoid
+/// extra copying.
+class MemoryObject {
+public:
+  virtual ~MemoryObject();
+
+  /// Returns the size of the region in bytes.  (The region is contiguous, so
+  /// the highest valid address of the region is getExtent() - 1).
+  ///
+  /// @result         - The size of the region.
+  virtual uint64_t getExtent() const = 0;
+
+  /// Tries to read a contiguous range of bytes from the region, up to the end
+  /// of the region.
+  ///
+  /// @param Buf      - A pointer to a buffer to be filled in.  Must be non-NULL
+  ///                   and large enough to hold size bytes.
+  /// @param Size     - The number of bytes to copy.
+  /// @param Address  - The address of the first byte, in the same space as
+  ///                   getBase().
+  /// @result         - The number of bytes read.
+  virtual uint64_t readBytes(uint8_t *Buf, uint64_t Size,
+                             uint64_t Address) const = 0;
+
+  /// Ensures that the requested data is in memory, and returns a pointer to it.
+  /// More efficient than using readBytes if the data is already in memory. May
+  /// block until (address - base + size) bytes have been read
+  /// @param address - address of the byte, in the same space as getBase()
+  /// @param size    - amount of data that must be available on return
+  /// @result        - valid pointer to the requested data
+  virtual const uint8_t *getPointer(uint64_t address, uint64_t size) const = 0;
+
+  /// Returns true if the address is within the object (i.e. between base and
+  /// base + extent - 1 inclusive). May block until (address - base) bytes have
+  /// been read
+  /// @param address - address of the byte, in the same space as getBase()
+  /// @result        - true if the address may be read with readByte()
+  virtual bool isValidAddress(uint64_t address) const = 0;
+};
+
+}
+
+#endif