LLVM  7.0.0svn
DWARFDebugArangeSet.cpp
Go to the documentation of this file.
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  uint32_t AddressSize) const {
22  OS << format("[0x%*.*" PRIx64 ", ", AddressSize * 2, AddressSize * 2, Address)
23  << format(" 0x%*.*" PRIx64 ")", AddressSize * 2, AddressSize * 2,
24  getEndAddress());
25 }
26 
28  Offset = -1U;
29  std::memset(&HeaderData, 0, sizeof(Header));
30  ArangeDescriptors.clear();
31 }
32 
33 bool
35  if (data.isValidOffset(*offset_ptr)) {
36  ArangeDescriptors.clear();
37  Offset = *offset_ptr;
38 
39  // 7.20 Address Range Table
40  //
41  // Each set of entries in the table of address ranges contained in
42  // the .debug_aranges section begins with a header consisting of: a
43  // 4-byte length containing the length of the set of entries for this
44  // compilation unit, not including the length field itself; a 2-byte
45  // version identifier containing the value 2 for DWARF Version 2; a
46  // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer
47  // containing the size in bytes of an address (or the offset portion of
48  // an address for segmented addressing) on the target system; and a
49  // 1-byte unsigned integer containing the size in bytes of a segment
50  // descriptor on the target system. This header is followed by a series
51  // of tuples. Each tuple consists of an address and a length, each in
52  // the size appropriate for an address on the target architecture.
53  HeaderData.Length = data.getU32(offset_ptr);
54  HeaderData.Version = data.getU16(offset_ptr);
55  HeaderData.CuOffset = data.getU32(offset_ptr);
56  HeaderData.AddrSize = data.getU8(offset_ptr);
57  HeaderData.SegSize = data.getU8(offset_ptr);
58 
59  // Perform basic validation of the header fields.
60  if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) ||
61  (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) {
62  clear();
63  return false;
64  }
65 
66  // The first tuple following the header in each set begins at an offset
67  // that is a multiple of the size of a single tuple (that is, twice the
68  // size of an address). The header is padded, if necessary, to the
69  // appropriate boundary.
70  const uint32_t header_size = *offset_ptr - Offset;
71  const uint32_t tuple_size = HeaderData.AddrSize * 2;
72  uint32_t first_tuple_offset = 0;
73  while (first_tuple_offset < header_size)
74  first_tuple_offset += tuple_size;
75 
76  *offset_ptr = Offset + first_tuple_offset;
77 
78  Descriptor arangeDescriptor;
79 
80  static_assert(sizeof(arangeDescriptor.Address) ==
81  sizeof(arangeDescriptor.Length),
82  "Different datatypes for addresses and sizes!");
83  assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize);
84 
85  while (data.isValidOffset(*offset_ptr)) {
86  arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
87  arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
88 
89  // Each set of tuples is terminated by a 0 for the address and 0
90  // for the length.
91  if (arangeDescriptor.Address || arangeDescriptor.Length)
92  ArangeDescriptors.push_back(arangeDescriptor);
93  else
94  break; // We are done if we get a zero address and length
95  }
96 
97  return !ArangeDescriptors.empty();
98  }
99  return false;
100 }
101 
103  OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ",
104  HeaderData.Length, HeaderData.Version)
105  << format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n",
106  HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize);
107 
108  for (const auto &Desc : ArangeDescriptors) {
109  Desc.dump(OS, HeaderData.AddrSize);
110  OS << '\n';
111  }
112 }
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.
uint32_t getU32(uint32_t *offset_ptr) const
Extract a uint32_t value from *offset_ptr.
void dump(raw_ostream &OS) const
bool isValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const
Test the availability of length bytes of data from offset.
void dump(raw_ostream &OS, uint32_t AddressSize) 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)
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