LLVM  8.0.0svn
Decompressor.h
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1 //===-- Decompressor.h ------------------------------------------*- C++ -*-===//
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 #ifndef LLVM_OBJECT_DECOMPRESSOR_H
11 #define LLVM_OBJECT_DECOMPRESSOR_H
12 
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/StringRef.h"
15 #include "llvm/Object/ObjectFile.h"
16 
17 namespace llvm {
18 namespace object {
19 
20 /// Decompressor helps to handle decompression of compressed sections.
21 class Decompressor {
22 public:
23  /// Create decompressor object.
24  /// @param Name Section name.
25  /// @param Data Section content.
26  /// @param IsLE Flag determines if Data is in little endian form.
27  /// @param Is64Bit Flag determines if object is 64 bit.
29  bool IsLE, bool Is64Bit);
30 
31  /// Resize the buffer and uncompress section data into it.
32  /// @param Out Destination buffer.
33  template <class T> Error resizeAndDecompress(T &Out) {
34  Out.resize(DecompressedSize);
35  return decompress({Out.data(), (size_t)DecompressedSize});
36  }
37 
38  /// Uncompress section data to raw buffer provided.
39  /// @param Buffer Destination buffer.
41 
42  /// Return memory buffer size required for decompression.
43  uint64_t getDecompressedSize() { return DecompressedSize; }
44 
45  /// Return true if section is compressed, including gnu-styled case.
46  static bool isCompressed(const object::SectionRef &Section);
47 
48  /// Return true if section is a ELF compressed one.
49  static bool isCompressedELFSection(uint64_t Flags, StringRef Name);
50 
51  /// Return true if section name matches gnu style compressed one.
52  static bool isGnuStyle(StringRef Name);
53 
54 private:
55  Decompressor(StringRef Data);
56 
57  Error consumeCompressedGnuHeader();
58  Error consumeCompressedZLibHeader(bool Is64Bit, bool IsLittleEndian);
59 
60  StringRef SectionData;
61  uint64_t DecompressedSize;
62 };
63 
64 } // end namespace object
65 } // end namespace llvm
66 
67 #endif // LLVM_OBJECT_DECOMPRESSOR_H
static bool isCompressed(const object::SectionRef &Section)
Return true if section is compressed, including gnu-styled case.
static bool isGnuStyle(StringRef Name)
Return true if section name matches gnu style compressed one.
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Error resizeAndDecompress(T &Out)
Resize the buffer and uncompress section data into it.
Definition: Decompressor.h:33
amdgpu Simplify well known AMD library false Value Value const Twine & Name
Decompressor helps to handle decompression of compressed sections.
Definition: Decompressor.h:21
uint64_t getDecompressedSize()
Return memory buffer size required for decompression.
Definition: Decompressor.h:43
Tagged union holding either a T or a Error.
Definition: CachePruning.h:23
MutableArrayRef - Represent a mutable reference to an array (0 or more elements consecutively in memo...
Definition: ArrayRef.h:291
Error decompress(MutableArrayRef< char > Buffer)
Uncompress section data to raw buffer provided.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:158
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
static bool isCompressedELFSection(uint64_t Flags, StringRef Name)
Return true if section is a ELF compressed one.
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:81
static Expected< Decompressor > create(StringRef Name, StringRef Data, bool IsLE, bool Is64Bit)
Create decompressor object.