1 //===-- llvm/CodeGen/DwarfUnit.h - Dwarf Compile Unit ---*- C++ -*--===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf compile unit.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
17 #include "DwarfDebug.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/Optional.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/CodeGen/AsmPrinter.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"
31 class MachineLocation;
36 class DwarfCompileUnit;
38 // Data structure to hold a range for range lists.
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; }
47 const MCSymbol *Start, *End;
52 // Index for locating within the debug_range section this particular span.
55 SmallVector<RangeSpan, 2> Ranges;
58 RangeSpanList(MCSymbol *Sym, SmallVector<RangeSpan, 2> Ranges)
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); }
65 //===----------------------------------------------------------------------===//
66 /// This dwarf writer support class manages information associated with a
70 /// A numeric ID unique among all CUs in the module
73 /// MDNode for the compile unit.
74 const DICompileUnit *CUNode;
76 /// Unit debug information entry.
79 /// Offset of the UnitDie from beginning of debug info section.
80 unsigned DebugInfoOffset;
82 /// Target of Dwarf emission.
85 // Holders for some common dwarf information.
89 /// An anonymous type for index type. Owned by UnitDie.
92 /// Tracks the mapping of unit level debug information variables to debug
93 /// information entries.
94 DenseMap<const MDNode *, DIE *> MDNodeToDieMap;
96 /// Tracks the mapping of unit level debug information descriptors to debug
97 /// information entries using a DIEEntry proxy.
98 DenseMap<const MDNode *, DIEEntry *> MDNodeToDIEEntryMap;
100 /// A list of all the DIEBlocks in use.
101 std::vector<DIEBlock *> DIEBlocks;
103 /// A list of all the DIELocs in use.
104 std::vector<DIELoc *> DIELocs;
106 /// This map is used to keep track of subprogram DIEs that need
107 /// DW_AT_containing_type attribute. This attribute points to a DIE that
108 /// corresponds to the MDNode mapped with the subprogram DIE.
109 DenseMap<DIE *, const DINode *> ContainingTypeMap;
111 // All DIEValues are allocated through this allocator.
112 BumpPtrAllocator DIEValueAllocator;
114 // A preallocated DIEValue because 1 is used frequently.
115 DIEInteger *DIEIntegerOne;
117 /// The section this unit will be emitted in.
118 const MCSection *Section;
120 DwarfUnit(unsigned UID, dwarf::Tag, const DICompileUnit *CU, AsmPrinter *A,
121 DwarfDebug *DW, DwarfFile *DWU);
123 /// \brief Add a string attribute data and value.
125 /// This is guaranteed to be in the local string pool instead of indirected.
126 void addLocalString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
128 void addIndexedString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
130 bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie);
133 virtual ~DwarfUnit();
135 void initSection(const MCSection *Section);
137 const MCSection *getSection() const {
143 AsmPrinter* getAsmPrinter() const { return Asm; }
144 unsigned getUniqueID() const { return UniqueID; }
145 uint16_t getLanguage() const { return CUNode->getSourceLanguage(); }
146 const DICompileUnit *getCUNode() const { return CUNode; }
147 DIE &getUnitDie() { return UnitDie; }
149 unsigned getDebugInfoOffset() const { return DebugInfoOffset; }
150 void setDebugInfoOffset(unsigned DbgInfoOff) { DebugInfoOffset = DbgInfoOff; }
152 /// \brief Return true if this compile unit has something to write out.
153 bool hasContent() const { return !UnitDie.getChildren().empty(); }
155 /// \brief Get string containing language specific context for a global name.
157 /// Walks the metadata parent chain in a language specific manner (using the
158 /// compile unit language) and returns it as a string. This is done at the
159 /// metadata level because DIEs may not currently have been added to the
160 /// parent context and walking the DIEs looking for names is more expensive
161 /// than walking the metadata.
162 std::string getParentContextString(const DIScope *Context) const;
164 /// Add a new global name to the compile unit.
165 virtual void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) {
168 /// Add a new global type to the compile unit.
169 virtual void addGlobalType(const DIType *Ty, const DIE &Die,
170 const DIScope *Context) {}
172 /// \brief Add a new name to the namespace accelerator table.
173 void addAccelNamespace(StringRef Name, const DIE &Die);
175 /// \brief Returns the DIE map slot for the specified debug variable.
177 /// We delegate the request to DwarfDebug when the MDNode can be part of the
178 /// type system, since DIEs for the type system can be shared across CUs and
179 /// the mappings are kept in DwarfDebug.
180 DIE *getDIE(const DINode *D) const;
182 /// \brief Returns a fresh newly allocated DIELoc.
183 DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc(); }
185 /// \brief Insert DIE into the map.
187 /// We delegate the request to DwarfDebug when the MDNode can be part of the
188 /// type system, since DIEs for the type system can be shared across CUs and
189 /// the mappings are kept in DwarfDebug.
190 void insertDIE(const DINode *Desc, DIE *D);
192 /// \brief Add a flag that is true to the DIE.
193 void addFlag(DIE &Die, dwarf::Attribute Attribute);
195 /// \brief Add an unsigned integer attribute data and value.
196 void addUInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
199 void addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer);
201 /// \brief Add an signed integer attribute data and value.
202 void addSInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
205 void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer);
207 /// \brief Add a string attribute data and value.
209 /// We always emit a reference to the string pool instead of immediate
210 /// strings so that DIEs have more predictable sizes. In the case of split
211 /// dwarf we emit an index into another table which gets us the static offset
212 /// into the string table.
213 void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
215 /// \brief Add a Dwarf label attribute data and value.
216 void addLabel(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form,
217 const MCSymbol *Label);
219 void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label);
221 /// \brief Add an offset into a section attribute data and value.
222 void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer);
224 /// \brief Add a dwarf op address data and value using the form given and an
225 /// op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
226 void addOpAddress(DIELoc &Die, const MCSymbol *Label);
228 /// \brief Add a label delta attribute data and value.
229 void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
232 /// \brief Add a DIE attribute data and value.
233 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry);
235 /// \brief Add a DIE attribute data and value.
236 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry *Entry);
238 void addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type);
240 /// \brief Add block data.
241 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block);
243 /// \brief Add block data.
244 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block);
246 /// \brief Add location information to specified debug information entry.
247 void addSourceLine(DIE &Die, unsigned Line, StringRef File,
248 StringRef Directory);
249 void addSourceLine(DIE &Die, const DILocalVariable *V);
250 void addSourceLine(DIE &Die, const DIGlobalVariable *G);
251 void addSourceLine(DIE &Die, const DISubprogram *SP);
252 void addSourceLine(DIE &Die, const DIType *Ty);
253 void addSourceLine(DIE &Die, const DINamespace *NS);
254 void addSourceLine(DIE &Die, const DIObjCProperty *Ty);
256 /// \brief Add constant value entry in variable DIE.
257 void addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty);
258 void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty);
259 void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty);
260 void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
261 void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
263 /// \brief Add constant value entry in variable DIE.
264 void addConstantFPValue(DIE &Die, const MachineOperand &MO);
265 void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
267 /// \brief Add a linkage name, if it isn't empty.
268 void addLinkageName(DIE &Die, StringRef LinkageName);
270 /// \brief Add template parameters in buffer.
271 void addTemplateParams(DIE &Buffer, DINodeArray TParams);
273 /// \brief Add register operand.
274 /// \returns false if the register does not exist, e.g., because it was never
276 bool addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
277 unsigned SizeInBits = 0, unsigned OffsetInBits = 0);
279 /// \brief Add register offset.
280 /// \returns false if the register does not exist, e.g., because it was never
282 bool addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset);
284 // FIXME: Should be reformulated in terms of addComplexAddress.
285 /// Start with the address based on the location provided, and generate the
286 /// DWARF information necessary to find the actual Block variable (navigating
287 /// the Block struct) based on the starting location. Add the DWARF
288 /// information to the die. Obsolete, please use addComplexAddress instead.
289 void addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
290 dwarf::Attribute Attribute,
291 const MachineLocation &Location);
293 /// \brief Add a new type attribute to the specified entity.
295 /// This takes and attribute parameter because DW_AT_friend attributes are
296 /// also type references.
297 void addType(DIE &Entity, const DIType *Ty,
298 dwarf::Attribute Attribute = dwarf::DW_AT_type);
300 DIE *getOrCreateNameSpace(const DINamespace *NS);
301 DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false);
303 void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
304 bool Minimal = false);
306 /// \brief Find existing DIE or create new DIE for the given type.
307 DIE *getOrCreateTypeDIE(const MDNode *N);
309 /// \brief Get context owner's DIE.
310 DIE *createTypeDIE(const DICompositeType *Ty);
312 /// \brief Get context owner's DIE.
313 DIE *getOrCreateContextDIE(const DIScope *Context);
315 /// \brief Construct DIEs for types that contain vtables.
316 void constructContainingTypeDIEs();
318 /// \brief Construct function argument DIEs.
319 void constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args);
321 /// Create a DIE with the given Tag, add the DIE to its parent, and
322 /// call insertDIE if MD is not null.
323 DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr);
325 /// Compute the size of a header for this unit, not including the initial
327 virtual unsigned getHeaderSize() const {
328 return sizeof(int16_t) + // DWARF version number
329 sizeof(int32_t) + // Offset Into Abbrev. Section
330 sizeof(int8_t); // Pointer Size (in bytes)
333 /// Emit the header for this unit, not including the initial length field.
334 virtual void emitHeader(bool UseOffsets);
336 virtual DwarfCompileUnit &getCU() = 0;
338 void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy);
341 /// \brief Create new static data member DIE.
342 DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT);
344 /// Look up the source ID with the given directory and source file names. If
345 /// none currently exists, create a new ID and insert it in the line table.
346 virtual unsigned getOrCreateSourceID(StringRef File, StringRef Directory) = 0;
348 /// \brief Look in the DwarfDebug map for the MDNode that corresponds to the
350 template <typename T> T *resolve(TypedDINodeRef<T> Ref) const {
351 return DD->resolve(Ref);
355 void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy);
356 void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy);
357 void constructTypeDIE(DIE &Buffer, const DISubroutineType *DTy);
358 void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy);
359 void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy);
360 void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy);
361 void constructMemberDIE(DIE &Buffer, const DIDerivedType *DT);
362 void constructTemplateTypeParameterDIE(DIE &Buffer,
363 const DITemplateTypeParameter *TP);
364 void constructTemplateValueParameterDIE(DIE &Buffer,
365 const DITemplateValueParameter *TVP);
367 /// \brief Return the default lower bound for an array.
369 /// If the DWARF version doesn't handle the language, return -1.
370 int64_t getDefaultLowerBound() const;
372 /// \brief Returns the DIE entry for the specified debug variable.
373 DIEEntry *getDIEEntry(const MDNode *N) const {
374 return MDNodeToDIEEntryMap.lookup(N);
377 /// \brief Insert debug information entry into the map.
378 void insertDIEEntry(const MDNode *N, DIEEntry *E) {
379 MDNodeToDIEEntryMap.insert(std::make_pair(N, E));
382 /// \brief Get an anonymous type for index type.
383 DIE *getIndexTyDie();
385 /// \brief Set D as anonymous type for index which can be reused later.
386 void setIndexTyDie(DIE *D) { IndexTyDie = D; }
388 /// \brief Creates a new DIEEntry to be a proxy for a debug information
390 DIEEntry *createDIEEntry(DIE &Entry);
392 /// If this is a named finished type then include it in the list of types for
393 /// the accelerator tables.
394 void updateAcceleratorTables(const DIScope *Context, const DIType *Ty,
397 virtual bool isDwoUnit() const = 0;
400 class DwarfTypeUnit : public DwarfUnit {
401 uint64_t TypeSignature;
403 DwarfCompileUnit &CU;
404 MCDwarfDwoLineTable *SplitLineTable;
406 unsigned getOrCreateSourceID(StringRef File, StringRef Directory) override;
407 bool isDwoUnit() const override;
410 DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A,
411 DwarfDebug *DW, DwarfFile *DWU,
412 MCDwarfDwoLineTable *SplitLineTable = nullptr);
414 void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; }
415 uint64_t getTypeSignature() const { return TypeSignature; }
416 void setType(const DIE *Ty) { this->Ty = Ty; }
418 /// Emit the header for this unit, not including the initial length field.
419 void emitHeader(bool UseOffsets) override;
420 unsigned getHeaderSize() const override {
421 return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature
422 sizeof(uint32_t); // Type DIE Offset
424 DwarfCompileUnit &getCU() override { return CU; }
426 } // end llvm namespace