LLVM  6.0.0svn
MSFCommon.h
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1 //===- MSFCommon.h - Common types and functions for MSF files ---*- 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_DEBUGINFO_MSF_MSFCOMMON_H
11 #define LLVM_DEBUGINFO_MSF_MSFCOMMON_H
12 
13 #include "llvm/ADT/ArrayRef.h"
14 #include "llvm/ADT/BitVector.h"
15 #include "llvm/Support/Endian.h"
16 #include "llvm/Support/Error.h"
18 #include <cstdint>
19 #include <vector>
20 
21 namespace llvm {
22 namespace msf {
23 
24 static const char Magic[] = {'M', 'i', 'c', 'r', 'o', 's', 'o', 'f',
25  't', ' ', 'C', '/', 'C', '+', '+', ' ',
26  'M', 'S', 'F', ' ', '7', '.', '0', '0',
27  '\r', '\n', '\x1a', 'D', 'S', '\0', '\0', '\0'};
28 
29 // The superblock is overlaid at the beginning of the file (offset 0).
30 // It starts with a magic header and is followed by information which
31 // describes the layout of the file system.
32 struct SuperBlock {
33  char MagicBytes[sizeof(Magic)];
34  // The file system is split into a variable number of fixed size elements.
35  // These elements are referred to as blocks. The size of a block may vary
36  // from system to system.
38  // The index of the free block map.
40  // This contains the number of blocks resident in the file system. In
41  // practice, NumBlocks * BlockSize is equivalent to the size of the MSF
42  // file.
44  // This contains the number of bytes which make up the directory.
46  // This field's purpose is not yet known.
48  // This contains the block # of the block map.
50 };
51 
52 struct MSFLayout {
53  MSFLayout() = default;
54 
55  const SuperBlock *SB = nullptr;
59  std::vector<ArrayRef<support::ulittle32_t>> StreamMap;
60 };
61 
62 /// \brief Describes the layout of a stream in an MSF layout. A "stream" here
63 /// is defined as any logical unit of data which may be arranged inside the MSF
64 /// file as a sequence of (possibly discontiguous) blocks. When we want to read
65 /// from a particular MSF Stream, we fill out a stream layout structure and the
66 /// reader uses it to determine which blocks in the underlying MSF file contain
67 /// the data, so that it can be pieced together in the right order.
69 public:
71  std::vector<support::ulittle32_t> Blocks;
72 };
73 
74 /// \brief Determine the layout of the FPM stream, given the MSF layout. An FPM
75 /// stream spans 1 or more blocks, each at equally spaced intervals throughout
76 /// the file.
78  bool IncludeUnusedFpmData = false,
79  bool AltFpm = false);
80 
82  switch (Size) {
83  case 512:
84  case 1024:
85  case 2048:
86  case 4096:
87  return true;
88  }
89  return false;
90 }
91 
92 // Super Block, Fpm0, Fpm1, and Block Map
93 inline uint32_t getMinimumBlockCount() { return 4; }
94 
95 // Super Block, Fpm0, and Fpm1 are reserved. The Block Map, although required
96 // need not be at block 3.
97 inline uint32_t getFirstUnreservedBlock() { return 3; }
98 
99 inline uint64_t bytesToBlocks(uint64_t NumBytes, uint64_t BlockSize) {
100  return divideCeil(NumBytes, BlockSize);
101 }
102 
103 inline uint64_t blockToOffset(uint64_t BlockNumber, uint64_t BlockSize) {
104  return BlockNumber * BlockSize;
105 }
106 
108  return L.SB->BlockSize;
109 }
110 
112  bool IncludeUnusedFpmData = false) {
113  if (IncludeUnusedFpmData)
114  return divideCeil(L.SB->NumBlocks, L.SB->BlockSize);
115 
116  // We want the minimum number of intervals required, where each interval can
117  // represent BlockSize * 8 blocks.
118  return divideCeil(L.SB->NumBlocks, 8 * L.SB->BlockSize);
119 }
120 
122 
123 } // end namespace msf
124 } // end namespace llvm
125 
126 #endif // LLVM_DEBUGINFO_MSF_MSFCOMMON_H
char MagicBytes[sizeof(Magic)]
Definition: MSFCommon.h:33
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Error validateSuperBlock(const SuperBlock &SB)
Definition: MSFCommon.cpp:20
uint32_t getNumFpmIntervals(const MSFLayout &L, bool IncludeUnusedFpmData=false)
Definition: MSFCommon.h:111
uint64_t blockToOffset(uint64_t BlockNumber, uint64_t BlockSize)
Definition: MSFCommon.h:103
uint32_t getMinimumBlockCount()
Definition: MSFCommon.h:93
Describes the layout of a stream in an MSF layout.
Definition: MSFCommon.h:68
MSFStreamLayout getFpmStreamLayout(const MSFLayout &Msf, bool IncludeUnusedFpmData=false, bool AltFpm=false)
Determine the layout of the FPM stream, given the MSF layout.
Definition: MSFCommon.cpp:63
uint32_t getFpmIntervalLength(const MSFLayout &L)
Definition: MSFCommon.h:107
std::vector< support::ulittle32_t > Blocks
Definition: MSFCommon.h:71
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
support::ulittle32_t BlockSize
Definition: MSFCommon.h:37
support::ulittle32_t BlockMapAddr
Definition: MSFCommon.h:49
static const char Magic[]
Definition: MSFCommon.h:24
support::ulittle32_t Unknown1
Definition: MSFCommon.h:47
ArrayRef< support::ulittle32_t > DirectoryBlocks
Definition: MSFCommon.h:57
BitVector FreePageMap
Definition: MSFCommon.h:56
uint64_t bytesToBlocks(uint64_t NumBytes, uint64_t BlockSize)
Definition: MSFCommon.h:99
uint64_t divideCeil(uint64_t Numerator, uint64_t Denominator)
Returns the integer ceil(Numerator / Denominator).
Definition: MathExtras.h:691
std::vector< ArrayRef< support::ulittle32_t > > StreamMap
Definition: MSFCommon.h:59
ArrayRef< support::ulittle32_t > StreamSizes
Definition: MSFCommon.h:58
support::ulittle32_t FreeBlockMapBlock
Definition: MSFCommon.h:39
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:156
bool isValidBlockSize(uint32_t Size)
Definition: MSFCommon.h:81
uint32_t getFirstUnreservedBlock()
Definition: MSFCommon.h:97
const SuperBlock * SB
Definition: MSFCommon.h:55
support::ulittle32_t NumDirectoryBytes
Definition: MSFCommon.h:45
support::ulittle32_t NumBlocks
Definition: MSFCommon.h:43