LLVM  9.0.0svn
DWARFDebugLine.h
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1 //===- DWARFDebugLine.h -----------------------------------------*- 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 #ifndef LLVM_DEBUGINFO_DWARFDEBUGLINE_H
10 #define LLVM_DEBUGINFO_DWARFDEBUGLINE_H
11 
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/ADT/StringRef.h"
20 #include "llvm/Support/MD5.h"
21 #include <cstdint>
22 #include <map>
23 #include <string>
24 #include <vector>
25 
26 namespace llvm {
27 
28 class DWARFUnit;
29 class raw_ostream;
30 
32 public:
33  struct FileNameEntry {
34  FileNameEntry() = default;
35 
37  uint64_t DirIdx = 0;
38  uint64_t ModTime = 0;
39  uint64_t Length = 0;
42  };
43 
44  /// Tracks which optional content types are present in a DWARF file name
45  /// entry format.
47  ContentTypeTracker() = default;
48 
49  /// Whether filename entries provide a modification timestamp.
50  bool HasModTime = false;
51  /// Whether filename entries provide a file size.
52  bool HasLength = false;
53  /// For v5, whether filename entries provide an MD5 checksum.
54  bool HasMD5 = false;
55  /// For v5, whether filename entries provide source text.
56  bool HasSource = false;
57 
58  /// Update tracked content types with \p ContentType.
59  void trackContentType(dwarf::LineNumberEntryFormat ContentType);
60  };
61 
62  struct Prologue {
63  Prologue();
64 
65  /// The size in bytes of the statement information for this compilation unit
66  /// (not including the total_length field itself).
67  uint64_t TotalLength;
68  /// Version, address size (starting in v5), and DWARF32/64 format; these
69  /// parameters affect interpretation of forms (used in the directory and
70  /// file tables starting with v5).
72  /// The number of bytes following the prologue_length field to the beginning
73  /// of the first byte of the statement program itself.
74  uint64_t PrologueLength;
75  /// In v5, size in bytes of a segment selector.
76  uint8_t SegSelectorSize;
77  /// The size in bytes of the smallest target machine instruction. Statement
78  /// program opcodes that alter the address register first multiply their
79  /// operands by this value.
80  uint8_t MinInstLength;
81  /// The maximum number of individual operations that may be encoded in an
82  /// instruction.
83  uint8_t MaxOpsPerInst;
84  /// The initial value of theis_stmtregister.
85  uint8_t DefaultIsStmt;
86  /// This parameter affects the meaning of the special opcodes. See below.
87  int8_t LineBase;
88  /// This parameter affects the meaning of the special opcodes. See below.
89  uint8_t LineRange;
90  /// The number assigned to the first special opcode.
91  uint8_t OpcodeBase;
92  /// This tracks which optional file format content types are present.
94  std::vector<uint8_t> StandardOpcodeLengths;
95  std::vector<DWARFFormValue> IncludeDirectories;
96  std::vector<FileNameEntry> FileNames;
97 
98  const dwarf::FormParams getFormParams() const { return FormParams; }
99  uint16_t getVersion() const { return FormParams.Version; }
100  uint8_t getAddressSize() const { return FormParams.AddrSize; }
101  bool isDWARF64() const { return FormParams.Format == dwarf::DWARF64; }
102 
103  uint32_t sizeofTotalLength() const { return isDWARF64() ? 12 : 4; }
104 
105  uint32_t sizeofPrologueLength() const { return isDWARF64() ? 8 : 4; }
106 
107  bool totalLengthIsValid() const;
108 
109  /// Length of the prologue in bytes.
110  uint32_t getLength() const {
111  return PrologueLength + sizeofTotalLength() + sizeof(getVersion()) +
112  sizeofPrologueLength();
113  }
114 
115  /// Length of the line table data in bytes (not including the prologue).
117  return TotalLength + sizeofTotalLength() - getLength();
118  }
119 
121  return LineBase + (int8_t)LineRange - 1;
122  }
123 
124  /// Get DWARF-version aware access to the file name entry at the provided
125  /// index.
127  getFileNameEntry(uint64_t Index) const;
128 
129  bool hasFileAtIndex(uint64_t FileIndex) const;
130 
131  bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
133  std::string &Result) const;
134 
135  void clear();
136  void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const;
137  Error parse(const DWARFDataExtractor &DebugLineData, uint32_t *OffsetPtr,
138  const DWARFContext &Ctx, const DWARFUnit *U = nullptr);
139  };
140 
141  /// Standard .debug_line state machine structure.
142  struct Row {
143  explicit Row(bool DefaultIsStmt = false);
144 
145  /// Called after a row is appended to the matrix.
146  void postAppend();
147  void reset(bool DefaultIsStmt);
148  void dump(raw_ostream &OS) const;
149 
150  static void dumpTableHeader(raw_ostream &OS);
151 
152  static bool orderByAddress(const Row &LHS, const Row &RHS) {
153  return std::tie(LHS.Address.SectionIndex, LHS.Address.Address) <
154  std::tie(RHS.Address.SectionIndex, RHS.Address.Address);
155  }
156 
157  /// The program-counter value corresponding to a machine instruction
158  /// generated by the compiler and section index pointing to the section
159  /// containg this PC. If relocation information is present then section
160  /// index is the index of the section which contains above address.
161  /// Otherwise this is object::SectionedAddress::Undef value.
163  /// An unsigned integer indicating a source line number. Lines are numbered
164  /// beginning at 1. The compiler may emit the value 0 in cases where an
165  /// instruction cannot be attributed to any source line.
167  /// An unsigned integer indicating a column number within a source line.
168  /// Columns are numbered beginning at 1. The value 0 is reserved to indicate
169  /// that a statement begins at the 'left edge' of the line.
170  uint16_t Column;
171  /// An unsigned integer indicating the identity of the source file
172  /// corresponding to a machine instruction.
173  uint16_t File;
174  /// An unsigned integer representing the DWARF path discriminator value
175  /// for this location.
177  /// An unsigned integer whose value encodes the applicable instruction set
178  /// architecture for the current instruction.
179  uint8_t Isa;
180  /// A boolean indicating that the current instruction is the beginning of a
181  /// statement.
182  uint8_t IsStmt : 1,
183  /// A boolean indicating that the current instruction is the
184  /// beginning of a basic block.
185  BasicBlock : 1,
186  /// A boolean indicating that the current address is that of the
187  /// first byte after the end of a sequence of target machine
188  /// instructions.
189  EndSequence : 1,
190  /// A boolean indicating that the current address is one (of possibly
191  /// many) where execution should be suspended for an entry breakpoint
192  /// of a function.
193  PrologueEnd : 1,
194  /// A boolean indicating that the current address is one (of possibly
195  /// many) where execution should be suspended for an exit breakpoint
196  /// of a function.
197  EpilogueBegin : 1;
198  };
199 
200  /// Represents a series of contiguous machine instructions. Line table for
201  /// each compilation unit may consist of multiple sequences, which are not
202  /// guaranteed to be in the order of ascending instruction address.
203  struct Sequence {
204  Sequence();
205 
206  /// Sequence describes instructions at address range [LowPC, HighPC)
207  /// and is described by line table rows [FirstRowIndex, LastRowIndex).
208  uint64_t LowPC;
209  uint64_t HighPC;
210  /// If relocation information is present then this is the index of the
211  /// section which contains above addresses. Otherwise this is
212  /// object::SectionedAddress::Undef value.
213  uint64_t SectionIndex;
214  unsigned FirstRowIndex;
215  unsigned LastRowIndex;
216  bool Empty;
217 
218  void reset();
219 
220  static bool orderByHighPC(const Sequence &LHS, const Sequence &RHS) {
221  return std::tie(LHS.SectionIndex, LHS.HighPC) <
222  std::tie(RHS.SectionIndex, RHS.HighPC);
223  }
224 
225  bool isValid() const {
226  return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex);
227  }
228 
230  return SectionIndex == PC.SectionIndex &&
231  (LowPC <= PC.Address && PC.Address < HighPC);
232  }
233  };
234 
235  struct LineTable {
236  LineTable();
237 
238  /// Represents an invalid row
239  const uint32_t UnknownRowIndex = UINT32_MAX;
240 
241  void appendRow(const DWARFDebugLine::Row &R) { Rows.push_back(R); }
242 
244  Sequences.push_back(S);
245  }
246 
247  /// Returns the index of the row with file/line info for a given address,
248  /// or UnknownRowIndex if there is no such row.
249  uint32_t lookupAddress(object::SectionedAddress Address) const;
250 
251  bool lookupAddressRange(object::SectionedAddress Address, uint64_t Size,
252  std::vector<uint32_t> &Result) const;
253 
254  bool hasFileAtIndex(uint64_t FileIndex) const {
255  return Prologue.hasFileAtIndex(FileIndex);
256  }
257 
258  /// Extracts filename by its index in filename table in prologue.
259  /// In Dwarf 4, the files are 1-indexed and the current compilation file
260  /// name is not represented in the list. In DWARF v5, the files are
261  /// 0-indexed and the primary source file has the index 0.
262  /// Returns true on success.
263  bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
265  std::string &Result) const {
266  return Prologue.getFileNameByIndex(FileIndex, CompDir, Kind, Result);
267  }
268 
269  /// Fills the Result argument with the file and line information
270  /// corresponding to Address. Returns true on success.
271  bool getFileLineInfoForAddress(object::SectionedAddress Address,
272  const char *CompDir,
274  DILineInfo &Result) const;
275 
276  void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const;
277  void clear();
278 
279  /// Parse prologue and all rows.
280  Error parse(
281  DWARFDataExtractor &DebugLineData, uint32_t *OffsetPtr,
282  const DWARFContext &Ctx, const DWARFUnit *U,
283  std::function<void(Error)> RecoverableErrorCallback,
284  raw_ostream *OS = nullptr);
285 
286  using RowVector = std::vector<Row>;
287  using RowIter = RowVector::const_iterator;
288  using SequenceVector = std::vector<Sequence>;
289  using SequenceIter = SequenceVector::const_iterator;
290 
294 
295  private:
296  uint32_t findRowInSeq(const DWARFDebugLine::Sequence &Seq,
297  object::SectionedAddress Address) const;
299  getSourceByIndex(uint64_t FileIndex,
301 
302  uint32_t lookupAddressImpl(object::SectionedAddress Address) const;
303 
304  bool lookupAddressRangeImpl(object::SectionedAddress Address, uint64_t Size,
305  std::vector<uint32_t> &Result) const;
306  };
307 
308  const LineTable *getLineTable(uint32_t Offset) const;
310  DWARFDataExtractor &DebugLineData, uint32_t Offset,
311  const DWARFContext &Ctx, const DWARFUnit *U,
312  std::function<void(Error)> RecoverableErrorCallback);
313 
314  /// Helper to allow for parsing of an entire .debug_line section in sequence.
316  public:
319  using LineToUnitMap = std::map<uint64_t, DWARFUnit *>;
320 
322  tu_range TUs);
323 
324  /// Get the next line table from the section. Report any issues via the
325  /// callbacks.
326  ///
327  /// \param RecoverableErrorCallback - any issues that don't prevent further
328  /// parsing of the table will be reported through this callback.
329  /// \param UnrecoverableErrorCallback - any issues that prevent further
330  /// parsing of the table will be reported through this callback.
331  /// \param OS - if not null, the parser will print information about the
332  /// table as it parses it.
333  LineTable
334  parseNext(
335  function_ref<void(Error)> RecoverableErrorCallback,
336  function_ref<void(Error)> UnrecoverableErrorCallback,
337  raw_ostream *OS = nullptr);
338 
339  /// Skip the current line table and go to the following line table (if
340  /// present) immediately.
341  ///
342  /// \param ErrorCallback - report any prologue parsing issues via this
343  /// callback.
344  void skip(function_ref<void(Error)> ErrorCallback);
345 
346  /// Indicates if the parser has parsed as much as possible.
347  ///
348  /// \note Certain problems with the line table structure might mean that
349  /// parsing stops before the end of the section is reached.
350  bool done() const { return Done; }
351 
352  /// Get the offset the parser has reached.
353  uint32_t getOffset() const { return Offset; }
354 
355  private:
356  DWARFUnit *prepareToParse(uint32_t Offset);
357  void moveToNextTable(uint32_t OldOffset, const Prologue &P);
358 
359  LineToUnitMap LineToUnit;
360 
361  DWARFDataExtractor &DebugLineData;
362  const DWARFContext &Context;
363  uint32_t Offset = 0;
364  bool Done = false;
365  };
366 
367 private:
368  struct ParsingState {
369  ParsingState(struct LineTable *LT);
370 
371  void resetRowAndSequence();
372  void appendRowToMatrix();
373 
374  /// Line table we're currently parsing.
375  struct LineTable *LineTable;
376  struct Row Row;
377  struct Sequence Sequence;
378  };
379 
380  using LineTableMapTy = std::map<uint32_t, LineTable>;
381  using LineTableIter = LineTableMapTy::iterator;
382  using LineTableConstIter = LineTableMapTy::const_iterator;
383 
384  LineTableMapTy LineTableMap;
385 };
386 
387 } // end namespace llvm
388 
389 #endif // LLVM_DEBUGINFO_DWARFDEBUGLINE_H
SequenceVector::const_iterator SequenceIter
uint64_t CallInst * C
A helper struct providing information about the byte size of DW_FORM values that vary in size dependi...
Definition: Dwarf.h:500
uint64_t LowPC
Sequence describes instructions at address range [LowPC, HighPC) and is described by line table rows ...
LLVMContext & Context
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Various leaf nodes.
Definition: ISDOpcodes.h:59
std::vector< Sequence > SequenceVector
uint32_t sizeofTotalLength() const
static bool orderByAddress(const Row &LHS, const Row &RHS)
uint32_t getLength() const
Length of the prologue in bytes.
uint32_t getStatementTableLength() const
Length of the line table data in bytes (not including the prologue).
uint8_t MinInstLength
The size in bytes of the smallest target machine instruction.
An efficient, type-erasing, non-owning reference to a callable.
Definition: STLExtras.h:116
uint32_t Line
An unsigned integer indicating a source line number.
bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, DILineInfoSpecifier::FileLineInfoKind Kind, std::string &Result) const
Extracts filename by its index in filename table in prologue.
void skip(CollectionType &C)
Definition: YAMLParser.h:388
const dwarf::FormParams getFormParams() const
std::vector< DWARFFormValue > IncludeDirectories
A format-neutral container for source line information.
Definition: DIContext.h:30
bool hasFileAtIndex(uint64_t FileIndex) const
object::SectionedAddress Address
The program-counter value corresponding to a machine instruction generated by the compiler and sectio...
uint8_t Isa
An unsigned integer whose value encodes the applicable instruction set architecture for the current i...
uint8_t MaxOpsPerInst
The maximum number of individual operations that may be encoded in an instruction.
uint64_t SectionIndex
If relocation information is present then this is the index of the section which contains above addre...
dwarf::FormParams FormParams
Version, address size (starting in v5), and DWARF32/64 format; these parameters affect interpretation...
ContentTypeTracker ContentTypes
This tracks which optional file format content types are present.
Represents a series of contiguous machine instructions.
uint32_t sizeofPrologueLength() const
Tagged union holding either a T or a Error.
Definition: CachePruning.h:22
uint8_t LineRange
This parameter affects the meaning of the special opcodes. See below.
uint8_t OpcodeBase
The number assigned to the first special opcode.
llvm::iterator_range< typename UnitVector::iterator > iterator_range
Definition: DWARFUnit.h:122
uint64_t TotalLength
The size in bytes of the statement information for this compilation unit (not including the total_len...
Expected< const LineTable * > getOrParseLineTable(DWARFDataExtractor &DebugLineData, uint32_t Offset, const DWARFContext &Ctx, const DWARFUnit *U, std::function< void(Error)> RecoverableErrorCallback)
Container for dump options that control which debug information will be dumped.
Definition: DIContext.h:167
#define P(N)
void dump(const SparseBitVector< ElementSize > &LHS, raw_ostream &out)
uint8_t SegSelectorSize
In v5, size in bytes of a segment selector.
uint16_t File
An unsigned integer indicating the identity of the source file corresponding to a machine instruction...
uint64_t PrologueLength
The number of bytes following the prologue_length field to the beginning of the first byte of the sta...
bool hasFileAtIndex(uint64_t FileIndex) const
static bool orderByHighPC(const Sequence &LHS, const Sequence &RHS)
llvm::Expected< Value > parse(llvm::StringRef JSON)
Parses the provided JSON source, or returns a ParseError.
Definition: JSON.cpp:510
int32_t getMaxLineIncrementForSpecialOpcode() const
void appendSequence(const DWARFDebugLine::Sequence &S)
Standard .debug_line state machine structure.
A DataExtractor (typically for an in-memory copy of an object-file section) plus a relocation map for...
uint16_t Column
An unsigned integer indicating a column number within a source line.
std::map< uint64_t, DWARFUnit * > LineToUnitMap
bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, DILineInfoSpecifier::FileLineInfoKind Kind, std::string &Result) const
void appendRow(const DWARFDebugLine::Row &R)
DWARFContext This data structure is the top level entity that deals with dwarf debug information pars...
Definition: DWARFContext.h:58
uint8_t PrologueEnd
A boolean indicating that the current address is one (of possibly many) where execution should be sus...
std::vector< uint8_t > StandardOpcodeLengths
A range adaptor for a pair of iterators.
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:211
Tracks which optional content types are present in a DWARF file name entry format.
std::vector< FileNameEntry > FileNames
uint32_t Discriminator
An unsigned integer representing the DWARF path discriminator value for this location.
RowVector::const_iterator RowIter
Sequence
A sequence of states that a pointer may go through in which an objc_retain and objc_release are actua...
Definition: PtrState.h:40
uint32_t Size
Definition: Profile.cpp:46
uint8_t DefaultIsStmt
The initial value of theis_stmtregister.
DwarfFormat Format
Definition: Dwarf.h:503
bool containsPC(object::SectionedAddress PC) const
int8_t LineBase
This parameter affects the meaning of the special opcodes. See below.
const LineTable * getLineTable(uint32_t Offset) const
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
print Print MemDeps of function
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
LineNumberEntryFormat
Definition: Dwarf.h:245
Helper to allow for parsing of an entire .debug_line section in sequence.
bool done() const
Indicates if the parser has parsed as much as possible.
uint32_t getOffset() const
Get the offset the parser has reached.