contrib/llvm/lib/DebugInfo/CodeView/ByteStream.cpp

   1 //===- ByteStream.cpp - Reads stream data from a byte sequence ------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/DebugInfo/CodeView/ByteStream.h"
  11 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
  12 #include "llvm/DebugInfo/CodeView/StreamReader.h"
  13 #include <cstring>
  14
  15 using namespace llvm;
  16 using namespace llvm::codeview;
  17
  18 static Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Src,
  19                         ArrayRef<uint8_t> Dest) {
  20   return make_error<CodeViewError>(cv_error_code::operation_unsupported,
  21                                    "ByteStream is immutable.");
  22 }
  23
  24 static Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Src,
  25                         MutableArrayRef<uint8_t> Dest) {
  26   if (Dest.size() < Src.size())
  27     return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
  28   if (Offset > Src.size() - Dest.size())
  29     return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
  30
  31   ::memcpy(Dest.data() + Offset, Src.data(), Src.size());
  32   return Error::success();
  33 }
  34
  35 template <bool Writable>
  36 Error ByteStream<Writable>::readBytes(uint32_t Offset, uint32_t Size,
  37                                       ArrayRef<uint8_t> &Buffer) const {
  38   if (Offset > Data.size())
  39     return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
  40   if (Data.size() < Size + Offset)
  41     return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
  42   Buffer = Data.slice(Offset, Size);
  43   return Error::success();
  44 }
  45
  46 template <bool Writable>
  47 Error ByteStream<Writable>::readLongestContiguousChunk(
  48     uint32_t Offset, ArrayRef<uint8_t> &Buffer) const {
  49   if (Offset >= Data.size())
  50     return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
  51   Buffer = Data.slice(Offset);
  52   return Error::success();
  53 }
  54
  55 template <bool Writable>
  56 Error ByteStream<Writable>::writeBytes(uint32_t Offset,
  57                                        ArrayRef<uint8_t> Buffer) const {
  58   return ::writeBytes(Offset, Buffer, Data);
  59 }
  60
  61 template <bool Writable> uint32_t ByteStream<Writable>::getLength() const {
  62   return Data.size();
  63 }
  64
  65 template <bool Writable> Error ByteStream<Writable>::commit() const {
  66   return Error::success();
  67 }
  68
  69 template <bool Writable> StringRef ByteStream<Writable>::str() const {
  70   const char *CharData = reinterpret_cast<const char *>(Data.data());
  71   return StringRef(CharData, Data.size());
  72 }
  73
  74 namespace llvm {
  75 namespace codeview {
  76 template class ByteStream<true>;
  77 template class ByteStream<false>;
  78 }
  79 }