LLVM  9.0.0svn
Decompressor.h
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1 //===-- Decompressor.h ------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===/
8 
9 #ifndef LLVM_OBJECT_DECOMPRESSOR_H
10 #define LLVM_OBJECT_DECOMPRESSOR_H
11 
12 #include "llvm/ADT/SmallString.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/Object/ObjectFile.h"
15 
16 namespace llvm {
17 namespace object {
18 
19 /// Decompressor helps to handle decompression of compressed sections.
20 class Decompressor {
21 public:
22  /// Create decompressor object.
23  /// @param Name Section name.
24  /// @param Data Section content.
25  /// @param IsLE Flag determines if Data is in little endian form.
26  /// @param Is64Bit Flag determines if object is 64 bit.
28  bool IsLE, bool Is64Bit);
29 
30  /// Resize the buffer and uncompress section data into it.
31  /// @param Out Destination buffer.
32  template <class T> Error resizeAndDecompress(T &Out) {
33  Out.resize(DecompressedSize);
34  return decompress({Out.data(), (size_t)DecompressedSize});
35  }
36 
37  /// Uncompress section data to raw buffer provided.
38  /// @param Buffer Destination buffer.
40 
41  /// Return memory buffer size required for decompression.
42  uint64_t getDecompressedSize() { return DecompressedSize; }
43 
44  /// Return true if section is compressed, including gnu-styled case.
45  static bool isCompressed(const object::SectionRef &Section);
46 
47  /// Return true if section is a ELF compressed one.
48  static bool isCompressedELFSection(uint64_t Flags, StringRef Name);
49 
50  /// Return true if section name matches gnu style compressed one.
51  static bool isGnuStyle(StringRef Name);
52 
53 private:
54  Decompressor(StringRef Data);
55 
56  Error consumeCompressedGnuHeader();
57  Error consumeCompressedZLibHeader(bool Is64Bit, bool IsLittleEndian);
58 
59  StringRef SectionData;
60  uint64_t DecompressedSize;
61 };
62 
63 } // end namespace object
64 } // end namespace llvm
65 
66 #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.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Error resizeAndDecompress(T &Out)
Resize the buffer and uncompress section data into it.
Definition: Decompressor.h:32
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
Decompressor helps to handle decompression of compressed sections.
Definition: Decompressor.h:20
uint64_t getDecompressedSize()
Return memory buffer size required for decompression.
Definition: Decompressor.h:42
Tagged union holding either a T or a Error.
Definition: CachePruning.h:22
MutableArrayRef - Represent a mutable reference to an array (0 or more elements consecutively in memo...
Definition: ArrayRef.h:290
Error decompress(MutableArrayRef< char > Buffer)
Uncompress section data to raw buffer provided.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
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.