LLVM  7.0.0svn
DwarfUnit.h
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1 //===-- llvm/CodeGen/DwarfUnit.h - Dwarf Compile Unit ---*- C++ -*--===//
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 //
10 // This file contains support for writing dwarf compile unit.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
16 
17 #include "DwarfDebug.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/Optional.h"
20 #include "llvm/ADT/StringMap.h"
22 #include "llvm/CodeGen/DIE.h"
23 #include "llvm/IR/DIBuilder.h"
24 #include "llvm/IR/DebugInfo.h"
25 #include "llvm/MC/MCDwarf.h"
26 #include "llvm/MC/MCExpr.h"
27 #include "llvm/MC/MCSection.h"
28 
29 namespace llvm {
30 
31 class MachineLocation;
32 class MachineOperand;
33 class ConstantInt;
34 class ConstantFP;
35 class DbgVariable;
36 class DwarfCompileUnit;
37 
38 // Data structure to hold a range for range lists.
39 class RangeSpan {
40 public:
41  RangeSpan(MCSymbol *S, MCSymbol *E) : Start(S), End(E) {}
42  const MCSymbol *getStart() const { return Start; }
43  const MCSymbol *getEnd() const { return End; }
44  void setEnd(const MCSymbol *E) { End = E; }
45 
46 private:
47  const MCSymbol *Start, *End;
48 };
49 
51 private:
52  // Index for locating within the debug_range section this particular span.
53  MCSymbol *RangeSym;
54  // List of ranges.
56 
57 public:
59  : RangeSym(Sym), Ranges(std::move(Ranges)) {}
60  MCSymbol *getSym() const { return RangeSym; }
61  const SmallVectorImpl<RangeSpan> &getRanges() const { return Ranges; }
62  void addRange(RangeSpan Range) { Ranges.push_back(Range); }
63 };
64 
65 //===----------------------------------------------------------------------===//
66 /// This dwarf writer support class manages information associated with a
67 /// source file.
68 class DwarfUnit : public DIEUnit {
69 protected:
70  /// MDNode for the compile unit.
72 
73  // All DIEValues are allocated through this allocator.
75 
76  /// Target of Dwarf emission.
78 
79  // Holders for some common dwarf information.
82 
83  /// An anonymous type for index type. Owned by DIEUnit.
85 
86  /// Tracks the mapping of unit level debug information variables to debug
87  /// information entries.
89 
90  /// A list of all the DIEBlocks in use.
91  std::vector<DIEBlock *> DIEBlocks;
92 
93  /// A list of all the DIELocs in use.
94  std::vector<DIELoc *> DIELocs;
95 
96  /// This map is used to keep track of subprogram DIEs that need
97  /// DW_AT_containing_type attribute. This attribute points to a DIE that
98  /// corresponds to the MDNode mapped with the subprogram DIE.
100 
102  DwarfFile *DWU);
103 
104  bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie);
105 
106  bool shareAcrossDWOCUs() const;
107  bool isShareableAcrossCUs(const DINode *D) const;
108 
109 public:
110  // Accessors.
111  AsmPrinter* getAsmPrinter() const { return Asm; }
112  uint16_t getLanguage() const { return CUNode->getSourceLanguage(); }
113  const DICompileUnit *getCUNode() const { return CUNode; }
114 
115  /// Return true if this compile unit has something to write out.
116  bool hasContent() const { return getUnitDie().hasChildren(); }
117 
118  /// Get string containing language specific context for a global name.
119  ///
120  /// Walks the metadata parent chain in a language specific manner (using the
121  /// compile unit language) and returns it as a string. This is done at the
122  /// metadata level because DIEs may not currently have been added to the
123  /// parent context and walking the DIEs looking for names is more expensive
124  /// than walking the metadata.
125  std::string getParentContextString(const DIScope *Context) const;
126 
127  /// Add a new global name to the compile unit.
128  virtual void addGlobalName(StringRef Name, const DIE &Die,
129  const DIScope *Context) = 0;
130 
131  /// Add a new global type to the compile unit.
132  virtual void addGlobalType(const DIType *Ty, const DIE &Die,
133  const DIScope *Context) = 0;
134 
135  /// Returns the DIE map slot for the specified debug variable.
136  ///
137  /// We delegate the request to DwarfDebug when the MDNode can be part of the
138  /// type system, since DIEs for the type system can be shared across CUs and
139  /// the mappings are kept in DwarfDebug.
140  DIE *getDIE(const DINode *D) const;
141 
142  /// Returns a fresh newly allocated DIELoc.
143  DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc; }
144 
145  /// Insert DIE into the map.
146  ///
147  /// We delegate the request to DwarfDebug when the MDNode can be part of the
148  /// type system, since DIEs for the type system can be shared across CUs and
149  /// the mappings are kept in DwarfDebug.
150  void insertDIE(const DINode *Desc, DIE *D);
151 
152  /// Add a flag that is true to the DIE.
153  void addFlag(DIE &Die, dwarf::Attribute Attribute);
154 
155  /// Add an unsigned integer attribute data and value.
156  void addUInt(DIEValueList &Die, dwarf::Attribute Attribute,
158 
159  void addUInt(DIEValueList &Block, dwarf::Form Form, uint64_t Integer);
160 
161  /// Add an signed integer attribute data and value.
162  void addSInt(DIEValueList &Die, dwarf::Attribute Attribute,
163  Optional<dwarf::Form> Form, int64_t Integer);
164 
165  void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer);
166 
167  /// Add a string attribute data and value.
168  ///
169  /// We always emit a reference to the string pool instead of immediate
170  /// strings so that DIEs have more predictable sizes. In the case of split
171  /// dwarf we emit an index into another table which gets us the static offset
172  /// into the string table.
173  void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
174 
175  /// Add a Dwarf label attribute data and value.
177  dwarf::Attribute Attribute,
178  dwarf::Form Form,
179  const MCSymbol *Label);
180 
181  void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label);
182 
183  /// Add an offset into a section attribute data and value.
184  void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer);
185 
186  /// Add a dwarf op address data and value using the form given and an
187  /// op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
188  void addOpAddress(DIELoc &Die, const MCSymbol *Label);
189 
190  /// Add a label delta attribute data and value.
191  void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
192  const MCSymbol *Lo);
193 
194  /// Add a DIE attribute data and value.
195  void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry);
196 
197  /// Add a DIE attribute data and value.
198  void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry);
199 
200  /// Add a type's DW_AT_signature and set the declaration flag.
201  void addDIETypeSignature(DIE &Die, uint64_t Signature);
202 
203  /// Add block data.
204  void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block);
205 
206  /// Add block data.
207  void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block);
208 
209  /// Add location information to specified debug information entry.
210  void addSourceLine(DIE &Die, unsigned Line, const DIFile *File);
211  void addSourceLine(DIE &Die, const DILocalVariable *V);
212  void addSourceLine(DIE &Die, const DIGlobalVariable *G);
213  void addSourceLine(DIE &Die, const DISubprogram *SP);
214  void addSourceLine(DIE &Die, const DIType *Ty);
215  void addSourceLine(DIE &Die, const DIObjCProperty *Ty);
216 
217  /// Add constant value entry in variable DIE.
218  void addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty);
219  void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty);
220  void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty);
221  void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
222  void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
223 
224  /// Add constant value entry in variable DIE.
225  void addConstantFPValue(DIE &Die, const MachineOperand &MO);
226  void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
227 
228  /// Add a linkage name, if it isn't empty.
229  void addLinkageName(DIE &Die, StringRef LinkageName);
230 
231  /// Add template parameters in buffer.
232  void addTemplateParams(DIE &Buffer, DINodeArray TParams);
233 
234  /// Add thrown types.
235  void addThrownTypes(DIE &Die, DINodeArray ThrownTypes);
236 
237  // FIXME: Should be reformulated in terms of addComplexAddress.
238  /// Start with the address based on the location provided, and generate the
239  /// DWARF information necessary to find the actual Block variable (navigating
240  /// the Block struct) based on the starting location. Add the DWARF
241  /// information to the die. Obsolete, please use addComplexAddress instead.
242  void addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
243  dwarf::Attribute Attribute,
244  const MachineLocation &Location);
245 
246  /// Add a new type attribute to the specified entity.
247  ///
248  /// This takes and attribute parameter because DW_AT_friend attributes are
249  /// also type references.
250  void addType(DIE &Entity, const DIType *Ty,
251  dwarf::Attribute Attribute = dwarf::DW_AT_type);
252 
253  DIE *getOrCreateNameSpace(const DINamespace *NS);
254  DIE *getOrCreateModule(const DIModule *M);
255  DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false);
256 
257  void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
258  bool SkipSPAttributes = false);
259 
260  /// Find existing DIE or create new DIE for the given type.
261  DIE *getOrCreateTypeDIE(const MDNode *N);
262 
263  /// Get context owner's DIE.
264  DIE *getOrCreateContextDIE(const DIScope *Context);
265 
266  /// Construct DIEs for types that contain vtables.
267  void constructContainingTypeDIEs();
268 
269  /// Construct function argument DIEs.
270  void constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args);
271 
272  /// Create a DIE with the given Tag, add the DIE to its parent, and
273  /// call insertDIE if MD is not null.
274  DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr);
275 
277  return DD->useSegmentedStringOffsetsTable();
278  }
279 
280  /// Compute the size of a header for this unit, not including the initial
281  /// length field.
282  virtual unsigned getHeaderSize() const {
283  return sizeof(int16_t) + // DWARF version number
284  sizeof(int32_t) + // Offset Into Abbrev. Section
285  sizeof(int8_t) + // Pointer Size (in bytes)
286  (DD->getDwarfVersion() >= 5 ? sizeof(int8_t)
287  : 0); // DWARF v5 unit type
288  }
289 
290  /// Emit the header for this unit, not including the initial length field.
291  virtual void emitHeader(bool UseOffsets) = 0;
292 
293  /// Add the DW_AT_str_offsets_base attribute to the unit DIE.
294  void addStringOffsetsStart();
295 
296  virtual DwarfCompileUnit &getCU() = 0;
297 
298  void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy);
299 
300  /// addSectionDelta - Add a label delta attribute data and value.
301  DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
302  const MCSymbol *Hi, const MCSymbol *Lo);
303 
304  /// Add a Dwarf section label attribute data and value.
305  DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
306  const MCSymbol *Label,
307  const MCSymbol *Sec);
308 
309 protected:
310  ~DwarfUnit();
311 
312  /// Create new static data member DIE.
313  DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT);
314 
315  /// Look up the source ID for the given file. If none currently exists,
316  /// create a new ID and insert it in the line table.
317  virtual unsigned getOrCreateSourceID(const DIFile *File) = 0;
318 
319  /// If the \p File has an MD5 checksum, return it as an MD5Result
320  /// allocated in the MCContext.
321  MD5::MD5Result *getMD5AsBytes(const DIFile *File);
322 
323  /// Look in the DwarfDebug map for the MDNode that corresponds to the
324  /// reference.
325  template <typename T> T *resolve(TypedDINodeRef<T> Ref) const {
326  return Ref.resolve();
327  }
328 
329  /// If this is a named finished type then include it in the list of types for
330  /// the accelerator tables.
331  void updateAcceleratorTables(const DIScope *Context, const DIType *Ty,
332  const DIE &TyDIE);
333 
334  /// Emit the common part of the header for this unit.
335  void emitCommonHeader(bool UseOffsets, dwarf::UnitType UT);
336 
337 private:
338  void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy);
339  void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy);
340  void constructTypeDIE(DIE &Buffer, const DISubroutineType *DTy);
341  void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy);
342  void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy);
343  void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy);
344  DIE &constructMemberDIE(DIE &Buffer, const DIDerivedType *DT);
345  void constructTemplateTypeParameterDIE(DIE &Buffer,
346  const DITemplateTypeParameter *TP);
347  void constructTemplateValueParameterDIE(DIE &Buffer,
348  const DITemplateValueParameter *TVP);
349 
350  /// Return the default lower bound for an array.
351  ///
352  /// If the DWARF version doesn't handle the language, return -1.
353  int64_t getDefaultLowerBound() const;
354 
355  /// Get an anonymous type for index type.
356  DIE *getIndexTyDie();
357 
358  /// Set D as anonymous type for index which can be reused later.
359  void setIndexTyDie(DIE *D) { IndexTyDie = D; }
360 
361  virtual bool isDwoUnit() const = 0;
362  const MCSymbol *getCrossSectionRelativeBaseAddress() const override;
363 };
364 
365 class DwarfTypeUnit final : public DwarfUnit {
366  uint64_t TypeSignature;
367  const DIE *Ty;
369  MCDwarfDwoLineTable *SplitLineTable;
370 
371  unsigned getOrCreateSourceID(const DIFile *File) override;
372  bool isDwoUnit() const override;
373 
374 public:
376  DwarfFile *DWU, MCDwarfDwoLineTable *SplitLineTable = nullptr);
377 
378  void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; }
379  void setType(const DIE *Ty) { this->Ty = Ty; }
380 
381  /// Get context owner's DIE.
382  DIE *createTypeDIE(const DICompositeType *Ty);
383 
384  /// Emit the header for this unit, not including the initial length field.
385  void emitHeader(bool UseOffsets) override;
386  unsigned getHeaderSize() const override {
387  return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature
388  sizeof(uint32_t); // Type DIE Offset
389  }
390  void addGlobalName(StringRef Name, const DIE &Die,
391  const DIScope *Context) override;
392  void addGlobalType(const DIType *Ty, const DIE &Die,
393  const DIScope *Context) override;
394  DwarfCompileUnit &getCU() override { return CU; }
395 };
396 } // end llvm namespace
397 #endif
const DICompileUnit * getCUNode() const
Definition: DwarfUnit.h:113
LLVMContext & Context
virtual unsigned getHeaderSize() const
Compute the size of a header for this unit, not including the initial length field.
Definition: DwarfUnit.h:282
std::vector< DIELoc * > DIELocs
A list of all the DIELocs in use.
Definition: DwarfUnit.h:94
DIELoc - Represents an expression location.
Definition: DIE.h:846
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
Attribute
Attributes.
Definition: Dwarf.h:107
Collects and handles dwarf debug information.
Definition: DwarfDebug.h:196
Metadata node.
Definition: Metadata.h:862
bool useSegmentedStringOffsetsTable() const
Definition: DwarfUnit.h:276
AsmPrinter * Asm
Target of Dwarf emission.
Definition: DwarfUnit.h:77
Tagged DWARF-like metadata node.
T * resolve(TypedDINodeRef< T > Ref) const
Look in the DwarfDebug map for the MDNode that corresponds to the reference.
Definition: DwarfUnit.h:325
Definition: BitVector.h:921
Array subrange.
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
Holds a subclass of DINode.
DenseMap< DIE *, const DINode * > ContainingTypeMap
This map is used to keep track of subprogram DIEs that need DW_AT_containing_type attribute...
Definition: DwarfUnit.h:99
const SmallVectorImpl< RangeSpan > & getRanges() const
Definition: DwarfUnit.h:61
Subprogram description.
AsmPrinter * getAsmPrinter() const
Definition: DwarfUnit.h:111
This class is used to track local variable information.
Definition: DwarfDebug.h:76
A list of DIE values.
Definition: DIE.h:589
DwarfCompileUnit & getCU() override
Definition: DwarfUnit.h:394
A pointer to another debug information entry.
Definition: DIE.h:294
This dwarf writer support class manages information associated with a source file.
Definition: DwarfUnit.h:68
MCSymbol * getSym() const
Definition: DwarfUnit.h:60
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:143
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
bool hasContent() const
Return true if this compile unit has something to write out.
Definition: DwarfUnit.h:116
A structured debug information entry.
Definition: DIE.h:662
DIELoc * getDIELoc()
Returns a fresh newly allocated DIELoc.
Definition: DwarfUnit.h:143
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:264
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:77
void setEnd(const MCSymbol *E)
Definition: DwarfUnit.h:44
DenseMap< const MDNode *, DIE * > MDNodeToDieMap
Tracks the mapping of unit level debug information variables to debug information entries...
Definition: DwarfUnit.h:88
bool useSegmentedStringOffsetsTable() const
Returns whether to generate a string offsets table with (possibly shared) contributions from each CU ...
Definition: DwarfDebug.h:520
const MCSymbol * getStart() const
Definition: DwarfUnit.h:42
DIE * IndexTyDie
An anonymous type for index type. Owned by DIEUnit.
Definition: DwarfUnit.h:84
Base class for scope-like contexts.
UnitType
Constants for unit types in DWARF v5.
Definition: Dwarf.h:321
uint16_t getLanguage() const
Definition: DwarfUnit.h:112
unsigned getHeaderSize() const override
Compute the size of a header for this unit, not including the initial length field.
Definition: DwarfUnit.h:386
Base class for types.
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
MachineOperand class - Representation of each machine instruction operand.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:862
const DataFlowGraph & G
Definition: RDFGraph.cpp:211
Represents a compile or type unit.
Definition: DIE.h:788
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
void setTypeSignature(uint64_t Signature)
Definition: DwarfUnit.h:378
unsigned getSourceLanguage() const
DwarfDebug * DD
Definition: DwarfUnit.h:80
Class for arbitrary precision integers.
Definition: APInt.h:69
A (clang) module that has been imported by the compile unit.
void setType(const DIE *Ty)
Definition: DwarfUnit.h:379
Type array for a subprogram.
RangeSpan(MCSymbol *S, MCSymbol *E)
Definition: DwarfUnit.h:41
#define N
void addRange(RangeSpan Range)
Definition: DwarfUnit.h:62
const DICompileUnit * CUNode
MDNode for the compile unit.
Definition: DwarfUnit.h:71
BumpPtrAllocator DIEValueAllocator
Definition: DwarfUnit.h:74
const MCSymbol * getEnd() const
Definition: DwarfUnit.h:43
RangeSpanList(MCSymbol *Sym, SmallVector< RangeSpan, 2 > Ranges)
Definition: DwarfUnit.h:58
The access may reference the value stored in memory.
std::vector< DIEBlock * > DIEBlocks
A list of all the DIEBlocks in use.
Definition: DwarfUnit.h:91
uint16_t getDwarfVersion() const
Returns the Dwarf Version.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
DIEBlock - Represents a block of values.
Definition: DIE.h:880
DwarfFile * DU
Definition: DwarfUnit.h:81
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
Basic type, like &#39;int&#39; or &#39;float&#39;.