LLVM  4.0.0
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 <algorithm>
14 #include <cassert>
15 using namespace llvm;
16 
18  Offset = -1U;
19  std::memset(&HeaderData, 0, sizeof(Header));
20  ArangeDescriptors.clear();
21 }
22 
23 bool
25  if (data.isValidOffset(*offset_ptr)) {
26  ArangeDescriptors.clear();
27  Offset = *offset_ptr;
28 
29  // 7.20 Address Range Table
30  //
31  // Each set of entries in the table of address ranges contained in
32  // the .debug_aranges section begins with a header consisting of: a
33  // 4-byte length containing the length of the set of entries for this
34  // compilation unit, not including the length field itself; a 2-byte
35  // version identifier containing the value 2 for DWARF Version 2; a
36  // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer
37  // containing the size in bytes of an address (or the offset portion of
38  // an address for segmented addressing) on the target system; and a
39  // 1-byte unsigned integer containing the size in bytes of a segment
40  // descriptor on the target system. This header is followed by a series
41  // of tuples. Each tuple consists of an address and a length, each in
42  // the size appropriate for an address on the target architecture.
43  HeaderData.Length = data.getU32(offset_ptr);
44  HeaderData.Version = data.getU16(offset_ptr);
45  HeaderData.CuOffset = data.getU32(offset_ptr);
46  HeaderData.AddrSize = data.getU8(offset_ptr);
47  HeaderData.SegSize = data.getU8(offset_ptr);
48 
49  // Perform basic validation of the header fields.
50  if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) ||
51  (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) {
52  clear();
53  return false;
54  }
55 
56  // The first tuple following the header in each set begins at an offset
57  // that is a multiple of the size of a single tuple (that is, twice the
58  // size of an address). The header is padded, if necessary, to the
59  // appropriate boundary.
60  const uint32_t header_size = *offset_ptr - Offset;
61  const uint32_t tuple_size = HeaderData.AddrSize * 2;
62  uint32_t first_tuple_offset = 0;
63  while (first_tuple_offset < header_size)
64  first_tuple_offset += tuple_size;
65 
66  *offset_ptr = Offset + first_tuple_offset;
67 
68  Descriptor arangeDescriptor;
69 
70  static_assert(sizeof(arangeDescriptor.Address) ==
71  sizeof(arangeDescriptor.Length),
72  "Different datatypes for addresses and sizes!");
73  assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize);
74 
75  while (data.isValidOffset(*offset_ptr)) {
76  arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
77  arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
78 
79  // Each set of tuples is terminated by a 0 for the address and 0
80  // for the length.
81  if (arangeDescriptor.Address || arangeDescriptor.Length)
82  ArangeDescriptors.push_back(arangeDescriptor);
83  else
84  break; // We are done if we get a zero address and length
85  }
86 
87  return !ArangeDescriptors.empty();
88  }
89  return false;
90 }
91 
93  OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ",
94  HeaderData.Length, HeaderData.Version)
95  << format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n",
96  HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize);
97 
98  const uint32_t hex_width = HeaderData.AddrSize * 2;
99  for (const auto &Desc : ArangeDescriptors) {
100  OS << format("[0x%*.*" PRIx64 " -", hex_width, hex_width, Desc.Address)
101  << format(" 0x%*.*" PRIx64 ")\n",
102  hex_width, hex_width, Desc.getEndAddress());
103  }
104 }
MachineInstrBuilder MachineInstrBuilder &DefMI const MCInstrDesc & Desc
bool isValidOffset(uint32_t offset) const
Test the validity of offset.
uint32_t getU32(uint32_t *offset_ptr) const
Extract a uint32_t value from *offset_ptr.
bool isValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const
Test the availability of length bytes of data from offset.
format_object< Ts...> format(const char *Fmt, const Ts &...Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
void dump(raw_ostream &OS) const
uint8_t getU8(uint32_t *offset_ptr) const
Extract a uint8_t value from *offset_ptr.
bool extract(DataExtractor data, uint32_t *offset_ptr)
uint16_t getU16(uint32_t *offset_ptr) const
Extract a uint16_t value from *offset_ptr.
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
uint64_t getUnsigned(uint32_t *offset_ptr, uint32_t byte_size) const
Extract an unsigned integer of size byte_size from *offset_ptr.