LLDB  mainline
DWARFDebugArangeSet.cpp
Go to the documentation of this file.
1 //===-- DWARFDebugArangeSet.cpp ---------------------------------*- 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 #include "DWARFDebugArangeSet.h"
10 
11 #include "SymbolFileDWARF.h"
12 #include "lldb/Utility/Stream.h"
13 #include "llvm/Object/Error.h"
14 #include <assert.h>
15 
16 using namespace lldb_private;
17 
19  : m_offset(DW_INVALID_OFFSET), m_header(), m_arange_descriptors() {
20  m_header.length = 0;
21  m_header.version = 0;
22  m_header.cu_offset = 0;
23  m_header.addr_size = 0;
24  m_header.seg_size = 0;
25 }
26 
29  m_header.length = 0;
30  m_header.version = 0;
31  m_header.cu_offset = 0;
32  m_header.addr_size = 0;
33  m_header.seg_size = 0;
34  m_arange_descriptors.clear();
35 }
36 
38  lldb::offset_t *offset_ptr) {
39  assert(data.ValidOffset(*offset_ptr));
40 
41  m_arange_descriptors.clear();
42  m_offset = *offset_ptr;
43 
44  // 7.20 Address Range Table
45  //
46  // Each set of entries in the table of address ranges contained in the
47  // .debug_aranges section begins with a header consisting of: a 4-byte
48  // length containing the length of the set of entries for this compilation
49  // unit, not including the length field itself; a 2-byte version identifier
50  // containing the value 2 for DWARF Version 2; a 4-byte offset into
51  // the.debug_infosection; a 1-byte unsigned integer containing the size in
52  // bytes of an address (or the offset portion of an address for segmented
53  // addressing) on the target system; and a 1-byte unsigned integer
54  // containing the size in bytes of a segment descriptor on the target
55  // system. This header is followed by a series of tuples. Each tuple
56  // consists of an address and a length, each in the size appropriate for an
57  // address on the target architecture.
58  m_header.length = data.GetDWARFInitialLength(offset_ptr);
59  m_header.version = data.GetU16(offset_ptr);
60  m_header.cu_offset = data.GetDWARFOffset(offset_ptr);
61  m_header.addr_size = data.GetU8(offset_ptr);
62  m_header.seg_size = data.GetU8(offset_ptr);
63 
64  // Try to avoid reading invalid arange sets by making sure:
65  // 1 - the version looks good
66  // 2 - the address byte size looks plausible
67  // 3 - the length seems to make sense
68  // size looks plausible
69  if (m_header.version < 2 || m_header.version > 5)
70  return llvm::make_error<llvm::object::GenericBinaryError>(
71  "Invalid arange header version");
72 
73  if (m_header.addr_size != 4 && m_header.addr_size != 8)
74  return llvm::make_error<llvm::object::GenericBinaryError>(
75  "Invalid arange header address size");
76 
77  if (m_header.length == 0)
78  return llvm::make_error<llvm::object::GenericBinaryError>(
79  "Invalid arange header length");
80 
81  if (!data.ValidOffset(m_offset + sizeof(m_header.length) + m_header.length -
82  1))
83  return llvm::make_error<llvm::object::GenericBinaryError>(
84  "Invalid arange header length");
85 
86  // The first tuple following the header in each set begins at an offset
87  // that is a multiple of the size of a single tuple (that is, twice the
88  // size of an address). The header is padded, if necessary, to the
89  // appropriate boundary.
90  const uint32_t header_size = *offset_ptr - m_offset;
91  const uint32_t tuple_size = m_header.addr_size << 1;
92  uint32_t first_tuple_offset = 0;
93  while (first_tuple_offset < header_size)
94  first_tuple_offset += tuple_size;
95 
96  *offset_ptr = m_offset + first_tuple_offset;
97 
98  Descriptor arangeDescriptor;
99 
100  static_assert(sizeof(arangeDescriptor.address) ==
101  sizeof(arangeDescriptor.length),
102  "DWARFDebugArangeSet::Descriptor.address and "
103  "DWARFDebugArangeSet::Descriptor.length must have same size");
104 
105  while (data.ValidOffset(*offset_ptr)) {
106  arangeDescriptor.address = data.GetMaxU64(offset_ptr, m_header.addr_size);
107  arangeDescriptor.length = data.GetMaxU64(offset_ptr, m_header.addr_size);
108 
109  // Each set of tuples is terminated by a 0 for the address and 0 for
110  // the length.
111  if (!arangeDescriptor.address && !arangeDescriptor.length)
112  return llvm::ErrorSuccess();
113 
114  m_arange_descriptors.push_back(arangeDescriptor);
115  }
116 
117  return llvm::make_error<llvm::object::GenericBinaryError>(
118  "arange descriptors not terminated by null entry");
119 }
120 
122 public:
123  DescriptorContainsAddress(dw_addr_t address) : m_address(address) {}
124  bool operator()(const DWARFDebugArangeSet::Descriptor &desc) const {
125  return (m_address >= desc.address) &&
126  (m_address < (desc.address + desc.length));
127  }
128 
129 private:
130  const dw_addr_t m_address;
131 };
132 
135  DescriptorConstIter pos =
136  std::find_if(m_arange_descriptors.begin(), end, // Range
137  DescriptorContainsAddress(address)); // Predicate
138  if (pos != end)
139  return m_header.cu_offset;
140 
141  return DW_INVALID_OFFSET;
142 }
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
dw_offset_t FindAddress(dw_addr_t address) const
llvm::Error Error
uint64_t dw_addr_t
Definition: dwarf.h:26
DescriptorContainsAddress(dw_addr_t address)
uint64_t GetDWARFInitialLength(lldb::offset_t *offset_ptr) const
uint64_t offset_t
Definition: lldb-types.h:87
bool ValidOffset(lldb::offset_t offset) const
Test the validity of offset.
uint64_t GetMaxU64(lldb::offset_t *offset_ptr, size_t byte_size) const
Extract an unsigned integer of size byte_size from *offset_ptr.
llvm::Error extract(const lldb_private::DWARFDataExtractor &data, lldb::offset_t *offset_ptr)
DescriptorColl m_arange_descriptors
DescriptorColl::const_iterator DescriptorConstIter
bool operator()(const DWARFDebugArangeSet::Descriptor &desc) const
dw_offset_t GetDWARFOffset(lldb::offset_t *offset_ptr) const
#define DW_INVALID_OFFSET
Definition: dwarf.h:34
uint8_t GetU8(lldb::offset_t *offset_ptr) const
Extract a uint8_t value from *offset_ptr.
uint16_t GetU16(lldb::offset_t *offset_ptr) const
Extract a uint16_t value from *offset_ptr.