LLVM  8.0.0svn
DWARFDebugLoc.cpp
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1 //===- DWARFDebugLoc.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/ADT/StringRef.h"
17 #include "llvm/Support/Compiler.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/WithColor.h"
21 #include <algorithm>
22 #include <cinttypes>
23 #include <cstdint>
24 
25 using namespace llvm;
26 
27 // When directly dumping the .debug_loc without a compile unit, we have to guess
28 // at the DWARF version. This only affects DW_OP_call_ref, which is a rare
29 // expression that LLVM doesn't produce. Guessing the wrong version means we
30 // won't be able to pretty print expressions in DWARF2 binaries produced by
31 // non-LLVM tools.
33  bool IsLittleEndian, unsigned AddressSize,
34  const MCRegisterInfo *MRI) {
35  DWARFDataExtractor Extractor(StringRef(Data.data(), Data.size()),
36  IsLittleEndian, AddressSize);
37  DWARFExpression(Extractor, dwarf::DWARF_VERSION, AddressSize).print(OS, MRI);
38 }
39 
40 void DWARFDebugLoc::LocationList::dump(raw_ostream &OS, bool IsLittleEndian,
41  unsigned AddressSize,
42  const MCRegisterInfo *MRI,
43  uint64_t BaseAddress,
44  unsigned Indent) const {
45  for (const Entry &E : Entries) {
46  OS << '\n';
47  OS.indent(Indent);
48  OS << format("[0x%*.*" PRIx64 ", ", AddressSize * 2, AddressSize * 2,
49  BaseAddress + E.Begin);
50  OS << format(" 0x%*.*" PRIx64 ")", AddressSize * 2, AddressSize * 2,
51  BaseAddress + E.End);
52  OS << ": ";
53 
54  dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
55  }
56 }
57 
60  auto It = std::lower_bound(
61  Locations.begin(), Locations.end(), Offset,
62  [](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
63  if (It != Locations.end() && It->Offset == Offset)
64  return &(*It);
65  return nullptr;
66 }
67 
69  Optional<uint64_t> Offset) const {
70  auto DumpLocationList = [&](const LocationList &L) {
71  OS << format("0x%8.8x: ", L.Offset);
72  L.dump(OS, IsLittleEndian, AddressSize, MRI, 0, 12);
73  OS << "\n\n";
74  };
75 
76  if (Offset) {
77  if (auto *L = getLocationListAtOffset(*Offset))
78  DumpLocationList(*L);
79  return;
80  }
81 
82  for (const LocationList &L : Locations) {
83  DumpLocationList(L);
84  }
85 }
86 
89  LocationList LL;
90  LL.Offset = *Offset;
91 
92  // 2.6.2 Location Lists
93  // A location list entry consists of:
94  while (true) {
95  Entry E;
96  if (!Data.isValidOffsetForDataOfSize(*Offset, 2 * Data.getAddressSize())) {
97  WithColor::error() << "location list overflows the debug_loc section.\n";
98  return None;
99  }
100 
101  // 1. A beginning address offset. ...
102  E.Begin = Data.getRelocatedAddress(Offset);
103 
104  // 2. An ending address offset. ...
105  E.End = Data.getRelocatedAddress(Offset);
106 
107  // The end of any given location list is marked by an end of list entry,
108  // which consists of a 0 for the beginning address offset and a 0 for the
109  // ending address offset.
110  if (E.Begin == 0 && E.End == 0)
111  return LL;
112 
113  if (!Data.isValidOffsetForDataOfSize(*Offset, 2)) {
114  WithColor::error() << "location list overflows the debug_loc section.\n";
115  return None;
116  }
117 
118  unsigned Bytes = Data.getU16(Offset);
119  if (!Data.isValidOffsetForDataOfSize(*Offset, Bytes)) {
120  WithColor::error() << "location list overflows the debug_loc section.\n";
121  return None;
122  }
123  // A single location description describing the location of the object...
124  StringRef str = Data.getData().substr(*Offset, Bytes);
125  *Offset += Bytes;
126  E.Loc.reserve(str.size());
127  llvm::copy(str, std::back_inserter(E.Loc));
128  LL.Entries.push_back(std::move(E));
129  }
130 }
131 
133  IsLittleEndian = data.isLittleEndian();
134  AddressSize = data.getAddressSize();
135 
136  uint32_t Offset = 0;
137  while (data.isValidOffset(Offset + data.getAddressSize() - 1)) {
138  if (auto LL = parseOneLocationList(data, &Offset))
139  Locations.push_back(std::move(*LL));
140  else
141  break;
142  }
143  if (data.isValidOffset(Offset))
144  WithColor::error() << "failed to consume entire .debug_loc section\n";
145 }
146 
149  unsigned Version) {
150  LocationList LL;
151  LL.Offset = *Offset;
152 
153  // dwarf::DW_LLE_end_of_list_entry is 0 and indicates the end of the list.
154  while (auto Kind =
155  static_cast<dwarf::LocationListEntry>(Data.getU8(Offset))) {
156 
157  Entry E;
158  E.Kind = Kind;
159  switch (Kind) {
161  E.Value0 = Data.getULEB128(Offset);
162  // Pre-DWARF 5 has different interpretation of the length field. We have
163  // to support both pre- and standartized styles for the compatibility.
164  if (Version < 5)
165  E.Value1 = Data.getU32(Offset);
166  else
167  E.Value1 = Data.getULEB128(Offset);
168  break;
170  E.Value0 = Data.getAddress(Offset);
171  E.Value1 = Data.getULEB128(Offset);
172  break;
174  E.Value0 = Data.getULEB128(Offset);
175  E.Value1 = Data.getULEB128(Offset);
176  break;
178  E.Value0 = Data.getAddress(Offset);
179  break;
180  default:
181  WithColor::error() << "dumping support for LLE of kind " << (int)Kind
182  << " not implemented\n";
183  return None;
184  }
185 
187  unsigned Bytes = Data.getU16(Offset);
188  // A single location description describing the location of the object...
189  StringRef str = Data.getData().substr(*Offset, Bytes);
190  *Offset += Bytes;
191  E.Loc.resize(str.size());
192  llvm::copy(str, E.Loc.begin());
193  }
194 
195  LL.Entries.push_back(std::move(E));
196  }
197  return LL;
198 }
199 
201  IsLittleEndian = data.isLittleEndian();
202  AddressSize = data.getAddressSize();
203 
204  uint32_t Offset = 0;
205  while (data.isValidOffset(Offset)) {
206  if (auto LL = parseOneLocationList(data, &Offset, Version))
207  Locations.push_back(std::move(*LL));
208  else
209  return;
210  }
211 }
212 
215  auto It = std::lower_bound(
216  Locations.begin(), Locations.end(), Offset,
217  [](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
218  if (It != Locations.end() && It->Offset == Offset)
219  return &(*It);
220  return nullptr;
221 }
222 
224  bool IsLittleEndian,
225  unsigned AddressSize,
226  const MCRegisterInfo *MRI,
227  unsigned Indent) const {
228  for (const Entry &E : Entries) {
229  switch (E.Kind) {
231  OS << '\n';
232  OS.indent(Indent);
233  OS << "Addr idx " << E.Value0 << " (w/ length " << E.Value1 << "): ";
234  break;
236  OS << '\n';
237  OS.indent(Indent);
238  OS << format("[0x%*.*" PRIx64 ", 0x%*.*" PRIx64 "): ", AddressSize * 2,
239  AddressSize * 2, E.Value0, AddressSize * 2, AddressSize * 2,
240  E.Value0 + E.Value1);
241  break;
243  OS << '\n';
244  OS.indent(Indent);
245  OS << format("[0x%*.*" PRIx64 ", 0x%*.*" PRIx64 "): ", AddressSize * 2,
246  AddressSize * 2, BaseAddr + E.Value0, AddressSize * 2,
247  AddressSize * 2, BaseAddr + E.Value1);
248  break;
250  BaseAddr = E.Value0;
251  break;
252  default:
253  llvm_unreachable("unreachable locations list kind");
254  }
255 
256  dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
257  }
258 }
259 
260 void DWARFDebugLoclists::dump(raw_ostream &OS, uint64_t BaseAddr,
261  const MCRegisterInfo *MRI,
262  Optional<uint64_t> Offset) const {
263  auto DumpLocationList = [&](const LocationList &L) {
264  OS << format("0x%8.8x: ", L.Offset);
265  L.dump(OS, BaseAddr, IsLittleEndian, AddressSize, MRI, /*Indent=*/12);
266  OS << "\n\n";
267  };
268 
269  if (Offset) {
270  if (auto *L = getLocationListAtOffset(*Offset))
271  DumpLocationList(*L);
272  return;
273  }
274 
275  for (const LocationList &L : Locations) {
276  DumpLocationList(L);
277  }
278 }
A list of locations that contain one variable.
Definition: DWARFDebugLoc.h:37
uint64_t getULEB128(uint32_t *offset_ptr) const
Extract a unsigned LEB128 value from *offset_ptr.
This class represents lattice values for constants.
Definition: AllocatorList.h:24
void dump(raw_ostream &OS, const MCRegisterInfo *RegInfo, Optional< uint64_t > Offset) const
Print the location lists found within the debug_loc section.
unsigned Offset
The beginning offset where this location list is stored in the debug_loc section. ...
Definition: DWARFDebugLoc.h:40
void print(raw_ostream &OS, const MCRegisterInfo *RegInfo, bool IsEH=false) const
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:138
static raw_ostream & error()
Convenience method for printing "error: " to stderr.
Definition: WithColor.cpp:61
format_object< Ts... > format(const char *Fmt, const Ts &... Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
raw_ostream & indent(unsigned NumSpaces)
indent - Insert &#39;NumSpaces&#39; spaces.
uint64_t getRelocatedAddress(uint32_t *Off, uint64_t *SecIx=nullptr) const
Extracts an address-sized value and applies a relocation to the result if one exists for the given of...
StringRef getData() const
Get the data pointed to by this extractor.
Definition: DataExtractor.h:55
void reserve(size_type N)
Definition: SmallVector.h:376
uint16_t getU16(uint32_t *offset_ptr) const
Extract a uint16_t value from *offset_ptr.
void dump(raw_ostream &OS, uint64_t BaseAddr, const MCRegisterInfo *RegInfo, Optional< uint64_t > Offset) const
uint32_t getU32(uint32_t *offset_ptr) const
Extract a uint32_t value from *offset_ptr.
A single location within a location list.
Definition: DWARFDebugLoc.h:27
void dump(raw_ostream &OS, uint64_t BaseAddr, bool IsLittleEndian, unsigned AddressSize, const MCRegisterInfo *RegInfo, unsigned Indent) const
SmallVector< char, 4 > Loc
The location of the variable within the specified range.
Definition: DWARFDebugLoc.h:33
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
auto lower_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range))
Provide wrappers to std::lower_bound which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1276
bool isLittleEndian() const
Get the endianness for this extractor.
Definition: DataExtractor.h:57
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE StringRef substr(size_t Start, size_t N=npos) const
Return a reference to the substring from [Start, Start + N).
Definition: StringRef.h:598
MCRegisterInfo base class - We assume that the target defines a static array of MCRegisterDesc object...
bool isValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const
Test the availability of length bytes of data from offset.
unsigned const MachineRegisterInfo * MRI
void dump(raw_ostream &OS, bool IsLittleEndian, unsigned AddressSize, const MCRegisterInfo *MRI, uint64_t BaseAddress, unsigned Indent) const
Dump this list on OS.
LocationList const * getLocationListAtOffset(uint64_t Offset) const
Return the location list at the given offset or nullptr.
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator begin()
Definition: SmallVector.h:129
uint8_t getAddressSize() const
Get the address size for this extractor.
Definition: DataExtractor.h:59
static Optional< LocationList > parseOneLocationList(DataExtractor Data, unsigned *Offset, unsigned Version)
uint8_t getU8(uint32_t *offset_ptr) const
Extract a uint8_t value from *offset_ptr.
static void dumpExpression(raw_ostream &OS, ArrayRef< char > Data, bool IsLittleEndian, unsigned AddressSize, const MCRegisterInfo *MRI)
uint64_t getAddress(uint32_t *offset_ptr) const
Extract an pointer from *offset_ptr.
Optional< LocationList > parseOneLocationList(DWARFDataExtractor Data, uint32_t *Offset)
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
const T * data() const
Definition: ArrayRef.h:146
A DataExtractor (typically for an in-memory copy of an object-file section) plus a relocation map for...
uint64_t Begin
The beginning address of the instruction range.
Definition: DWARFDebugLoc.h:29
LocationList const * getLocationListAtOffset(uint64_t Offset) const
Return the location list at the given offset or nullptr.
This file contains constants used for implementing Dwarf debug support.
void parse(DataExtractor data, unsigned Version)
uint64_t End
The ending address of the instruction range.
Definition: DWARFDebugLoc.h:31
bool isValidOffset(uint32_t offset) const
Test the validity of offset.
const unsigned Kind
Definition: JSON.cpp:592
SmallVector< char, 4 > Loc
Definition: DWARFDebugLoc.h:82
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
OutputIt copy(R &&Range, OutputIt Out)
Definition: STLExtras.h:1232
SmallVector< Entry, 2 > Entries
All the locations in which the variable is stored.
Definition: DWARFDebugLoc.h:42
const uint64_t Version
Definition: InstrProf.h:895
void parse(const DWARFDataExtractor &data)
Parse the debug_loc section accessible via the &#39;data&#39; parameter using the address size also given in ...
void resize(size_type N)
Definition: SmallVector.h:351