LLVM  6.0.0svn
BinaryStreamReader.cpp
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1 //===- BinaryStreamReader.cpp - Reads objects from a binary stream --------===//
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 
11 
14 
15 using namespace llvm;
17 
19 
21 
23  endianness Endian)
24  : Stream(Data, Endian) {}
25 
27  : Stream(Data, Endian) {}
28 
30  ArrayRef<uint8_t> &Buffer) {
31  if (auto EC = Stream.readLongestContiguousChunk(Offset, Buffer))
32  return EC;
33  Offset += Buffer.size();
34  return Error::success();
35 }
36 
38  if (auto EC = Stream.readBytes(Offset, Size, Buffer))
39  return EC;
40  Offset += Size;
41  return Error::success();
42 }
43 
45  uint32_t OriginalOffset = getOffset();
46  uint32_t FoundOffset = 0;
47  while (true) {
48  uint32_t ThisOffset = getOffset();
49  ArrayRef<uint8_t> Buffer;
50  if (auto EC = readLongestContiguousChunk(Buffer))
51  return EC;
52  StringRef S(reinterpret_cast<const char *>(Buffer.begin()), Buffer.size());
53  size_t Pos = S.find_first_of('\0');
54  if (LLVM_LIKELY(Pos != StringRef::npos)) {
55  FoundOffset = Pos + ThisOffset;
56  break;
57  }
58  }
59  assert(FoundOffset >= OriginalOffset);
60 
61  setOffset(OriginalOffset);
62  size_t Length = FoundOffset - OriginalOffset;
63 
64  if (auto EC = readFixedString(Dest, Length))
65  return EC;
66 
67  // Now set the offset back to after the null terminator.
68  setOffset(FoundOffset + 1);
69  return Error::success();
70 }
71 
73  uint32_t Length = 0;
74  uint32_t OriginalOffset = getOffset();
75  const UTF16 *C;
76  while (true) {
77  if (auto EC = readObject(C))
78  return EC;
79  if (*C == 0x0000)
80  break;
81  ++Length;
82  }
83  uint32_t NewOffset = getOffset();
84  setOffset(OriginalOffset);
85 
86  if (auto EC = readArray(Dest, Length))
87  return EC;
88  setOffset(NewOffset);
89  return Error::success();
90 }
91 
93  ArrayRef<uint8_t> Bytes;
94  if (auto EC = readBytes(Bytes, Length))
95  return EC;
96  Dest = StringRef(reinterpret_cast<const char *>(Bytes.begin()), Bytes.size());
97  return Error::success();
98 }
99 
101  return readStreamRef(Ref, bytesRemaining());
102 }
103 
105  if (bytesRemaining() < Length)
106  return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
107  Ref = Stream.slice(Offset, Length);
108  Offset += Length;
109  return Error::success();
110 }
111 
113  uint32_t Size) {
114  Stream.Offset = getOffset();
115  return readStreamRef(Stream.StreamData, Size);
116 }
117 
119  if (Amount > bytesRemaining())
120  return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
121  Offset += Amount;
122  return Error::success();
123 }
124 
126  uint32_t NewOffset = alignTo(Offset, Align);
127  return skip(NewOffset - Offset);
128 }
129 
130 uint8_t BinaryStreamReader::peek() const {
131  ArrayRef<uint8_t> Buffer;
132  auto EC = Stream.readBytes(Offset, 1, Buffer);
133  assert(!EC && "Cannot peek an empty buffer!");
134  llvm::consumeError(std::move(EC));
135  return Buffer[0];
136 }
137 
138 std::pair<BinaryStreamReader, BinaryStreamReader>
140  assert(getLength() >= Off);
141 
142  BinaryStreamRef First = Stream.drop_front(Offset);
143 
144  BinaryStreamRef Second = First.drop_front(Off);
145  First = First.keep_front(Off);
146  BinaryStreamReader W1{First};
147  BinaryStreamReader W2{Second};
148  return std::make_pair(W1, W2);
149 }
uint64_t CallInst * C
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
Error padToAlignment(uint32_t Align)
RefType slice(uint32_t Offset, uint32_t Len) const
Return a new BinaryStreamRef with the first Offset elements removed, and retaining exactly Len elemen...
Error readSubstream(BinarySubstreamRef &Stream, uint32_t Size)
Read Length bytes from the underlying stream into Stream.
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
#define LLVM_LIKELY(EXPR)
Definition: Compiler.h:175
iterator begin() const
Definition: ArrayRef.h:137
Error readWideString(ArrayRef< UTF16 > &Dest)
Similar to readCString, however read a null-terminated UTF16 string instead.
Error readObject(const T *&Dest)
Get a pointer to an object of type T from the underlying stream, as if by memcpy, and store the resul...
uint8_t peek() const
Examine the next byte of the underlying stream without advancing the stream&#39;s offset.
uint64_t alignTo(uint64_t Value, uint64_t Align, uint64_t Skew=0)
Returns the next integer (mod 2**64) that is greater than or equal to Value and is a multiple of Alig...
Definition: MathExtras.h:677
unsigned short UTF16
Definition: ConvertUTF.h:110
Error readCString(StringRef &Dest)
Read a null terminated string from Dest.
std::pair< BinaryStreamReader, BinaryStreamReader > split(uint32_t Offset) const
Error readFixedString(StringRef &Dest, uint32_t Length)
Read a Length byte string into Dest.
Error readBytes(uint32_t Offset, uint32_t Size, ArrayRef< uint8_t > &Buffer) const
Given an Offset into this StreamRef and a Size, return a reference to a buffer owned by the stream...
An interface for accessing data in a stream-like format, but which discourages copying.
Definition: BinaryStream.h:28
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
RefType drop_front(uint32_t N) const
Return a new BinaryStreamRef with the first N elements removed.
void consumeError(Error Err)
Consume a Error without doing anything.
Definition: Error.h:962
BinaryStreamRef StreamData
void setOffset(uint32_t Off)
static ErrorSuccess success()
Create a success value.
Definition: Error.h:313
BinaryStreamRef is to BinaryStream what ArrayRef is to an Array.
static const size_t npos
Definition: StringRef.h:51
Error readBytes(ArrayRef< uint8_t > &Buffer, uint32_t Size)
Read Size bytes from the underlying stream at the current offset and and set Buffer to the resulting ...
LLVM_NODISCARD size_t find_first_of(char C, size_t From=0) const
Find the first character in the string that is C, or npos if not found.
Definition: StringRef.h:395
Error readStreamRef(BinaryStreamRef &Ref)
Read the entire remainder of the underlying stream into Ref.
Error skip(uint32_t Amount)
Advance the stream&#39;s offset by Amount bytes.
Error readLongestContiguousChunk(uint32_t Offset, ArrayRef< uint8_t > &Buffer) const
Given an Offset into this BinaryStreamRef, return a reference to the largest buffer the stream could ...
uint32_t bytesRemaining() const
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
RefType keep_front(uint32_t N) const
Return a new BinaryStreamRef with only the first N elements remaining.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:156
Provides read only access to a subclass of BinaryStream.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Error readLongestContiguousChunk(ArrayRef< uint8_t > &Buffer)
Read as much as possible from the underlying string at the current offset without invoking a copy...
Error readArray(ArrayRef< T > &Array, uint32_t NumElements)
Get a reference to a NumElements element array of objects of type T from the underlying stream as if ...