LLVM  6.0.0svn
DWARFDebugArangeSet.cpp
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1 //===- DWARFDebugArangeSet.cpp --------------------------------------------===//
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 #include "llvm/Support/Format.h"
13 #include <cassert>
14 #include <cinttypes>
15 #include <cstdint>
16 #include <cstring>
17 
18 using namespace llvm;
19 
21  Offset = -1U;
22  std::memset(&HeaderData, 0, sizeof(Header));
23  ArangeDescriptors.clear();
24 }
25 
26 bool
28  if (data.isValidOffset(*offset_ptr)) {
29  ArangeDescriptors.clear();
30  Offset = *offset_ptr;
31 
32  // 7.20 Address Range Table
33  //
34  // Each set of entries in the table of address ranges contained in
35  // the .debug_aranges section begins with a header consisting of: a
36  // 4-byte length containing the length of the set of entries for this
37  // compilation unit, not including the length field itself; a 2-byte
38  // version identifier containing the value 2 for DWARF Version 2; a
39  // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer
40  // containing the size in bytes of an address (or the offset portion of
41  // an address for segmented addressing) on the target system; and a
42  // 1-byte unsigned integer containing the size in bytes of a segment
43  // descriptor on the target system. This header is followed by a series
44  // of tuples. Each tuple consists of an address and a length, each in
45  // the size appropriate for an address on the target architecture.
46  HeaderData.Length = data.getU32(offset_ptr);
47  HeaderData.Version = data.getU16(offset_ptr);
48  HeaderData.CuOffset = data.getU32(offset_ptr);
49  HeaderData.AddrSize = data.getU8(offset_ptr);
50  HeaderData.SegSize = data.getU8(offset_ptr);
51 
52  // Perform basic validation of the header fields.
53  if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) ||
54  (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) {
55  clear();
56  return false;
57  }
58 
59  // The first tuple following the header in each set begins at an offset
60  // that is a multiple of the size of a single tuple (that is, twice the
61  // size of an address). The header is padded, if necessary, to the
62  // appropriate boundary.
63  const uint32_t header_size = *offset_ptr - Offset;
64  const uint32_t tuple_size = HeaderData.AddrSize * 2;
65  uint32_t first_tuple_offset = 0;
66  while (first_tuple_offset < header_size)
67  first_tuple_offset += tuple_size;
68 
69  *offset_ptr = Offset + first_tuple_offset;
70 
71  Descriptor arangeDescriptor;
72 
73  static_assert(sizeof(arangeDescriptor.Address) ==
74  sizeof(arangeDescriptor.Length),
75  "Different datatypes for addresses and sizes!");
76  assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize);
77 
78  while (data.isValidOffset(*offset_ptr)) {
79  arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
80  arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
81 
82  // Each set of tuples is terminated by a 0 for the address and 0
83  // for the length.
84  if (arangeDescriptor.Address || arangeDescriptor.Length)
85  ArangeDescriptors.push_back(arangeDescriptor);
86  else
87  break; // We are done if we get a zero address and length
88  }
89 
90  return !ArangeDescriptors.empty();
91  }
92  return false;
93 }
94 
96  OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ",
97  HeaderData.Length, HeaderData.Version)
98  << format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n",
99  HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize);
100 
101  const uint32_t hex_width = HeaderData.AddrSize * 2;
102  for (const auto &Desc : ArangeDescriptors) {
103  OS << format("[0x%*.*" PRIx64 " -", hex_width, hex_width, Desc.Address)
104  << format(" 0x%*.*" PRIx64 ")\n",
105  hex_width, hex_width, Desc.getEndAddress());
106  }
107 }
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
format_object< Ts... > format(const char *Fmt, const Ts &... Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
uint16_t getU16(uint32_t *offset_ptr) const
Extract a uint16_t value from *offset_ptr.
uint8_t SegSize
The size in bytes of a segment descriptor on the target architecture.
uint32_t CuOffset
The offset from the beginning of the .debug_info section of the compilation unit entry referenced by ...
uint32_t getU32(uint32_t *offset_ptr) const
Extract a uint32_t value from *offset_ptr.
void dump(raw_ostream &OS) const
uint16_t Version
The DWARF version number.
bool isValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const
Test the availability of length bytes of data from offset.
uint8_t getU8(uint32_t *offset_ptr) const
Extract a uint8_t value from *offset_ptr.
uint32_t Length
The total length of the entries for that set, not including the length field itself.
bool extract(DataExtractor data, uint32_t *offset_ptr)
uint8_t AddrSize
The size in bytes of an address on the target architecture.
uint64_t getUnsigned(uint32_t *offset_ptr, uint32_t byte_size) const
Extract an unsigned integer of size byte_size from *offset_ptr.
bool isValidOffset(uint32_t offset) const
Test the validity of offset.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44