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"
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"
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:
RangeSpan(MCSymbol * S,MCSymbol * E)41   RangeSpan(MCSymbol *S, MCSymbol *E) : Start(S), End(E) {}
getStart()42   const MCSymbol *getStart() const { return Start; }
getEnd()43   const MCSymbol *getEnd() const { return End; }
setEnd(const MCSymbol * E)44   void setEnd(const MCSymbol *E) { End = E; }
45 
46 private:
47   const MCSymbol *Start, *End;
48 };
49 
50 class RangeSpanList {
51 private:
52   // Index for locating within the debug_range section this particular span.
53   MCSymbol *RangeSym;
54   // List of ranges.
55   SmallVector<RangeSpan, 2> Ranges;
56 
57 public:
RangeSpanList(MCSymbol * Sym,SmallVector<RangeSpan,2> Ranges)58   RangeSpanList(MCSymbol *Sym, SmallVector<RangeSpan, 2> Ranges)
59       : RangeSym(Sym), Ranges(std::move(Ranges)) {}
getSym()60   MCSymbol *getSym() const { return RangeSym; }
getRanges()61   const SmallVectorImpl<RangeSpan> &getRanges() const { return Ranges; }
addRange(RangeSpan Range)62   void addRange(RangeSpan Range) { Ranges.push_back(Range); }
63 };
64 
65 //===----------------------------------------------------------------------===//
66 /// Unit - This dwarf writer support class manages information associated
67 /// with a source file.
68 class DwarfUnit {
69 protected:
70   /// UniqueID - a numeric ID unique among all CUs in the module
71   unsigned UniqueID;
72 
73   /// Node - MDNode for the compile unit.
74   DICompileUnit CUNode;
75 
76   /// Unit debug information entry.
77   DIE UnitDie;
78 
79   /// Offset of the UnitDie from beginning of debug info section.
80   unsigned DebugInfoOffset;
81 
82   /// Asm - Target of Dwarf emission.
83   AsmPrinter *Asm;
84 
85   // Holders for some common dwarf information.
86   DwarfDebug *DD;
87   DwarfFile *DU;
88 
89   /// IndexTyDie - An anonymous type for index type.  Owned by UnitDie.
90   DIE *IndexTyDie;
91 
92   /// MDNodeToDieMap - Tracks the mapping of unit level debug information
93   /// variables to debug information entries.
94   DenseMap<const MDNode *, DIE *> MDNodeToDieMap;
95 
96   /// MDNodeToDIEEntryMap - Tracks the mapping of unit level debug information
97   /// descriptors to debug information entries using a DIEEntry proxy.
98   DenseMap<const MDNode *, DIEEntry *> MDNodeToDIEEntryMap;
99 
100   /// DIEBlocks - A list of all the DIEBlocks in use.
101   std::vector<DIEBlock *> DIEBlocks;
102 
103   /// DIELocs - A list of all the DIELocs in use.
104   std::vector<DIELoc *> DIELocs;
105 
106   /// ContainingTypeMap - This map is used to keep track of subprogram DIEs that
107   /// need 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 MDNode *> ContainingTypeMap;
110 
111   // DIEValueAllocator - All DIEValues are allocated through this allocator.
112   BumpPtrAllocator DIEValueAllocator;
113 
114   // DIEIntegerOne - A preallocated DIEValue because 1 is used frequently.
115   DIEInteger *DIEIntegerOne;
116 
117   /// The section this unit will be emitted in.
118   const MCSection *Section;
119 
120   DwarfUnit(unsigned UID, dwarf::Tag, DICompileUnit CU, AsmPrinter *A,
121             DwarfDebug *DW, DwarfFile *DWU);
122 
123 
124   /// Add a string attribute data and value.
125   void addLocalString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
126 
127   void addIndexedString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
128 
129   bool applySubprogramDefinitionAttributes(DISubprogram SP, DIE &SPDie);
130 
131 public:
132   virtual ~DwarfUnit();
133 
134   void initSection(const MCSection *Section);
135 
getSection()136   const MCSection *getSection() const {
137     assert(Section);
138     return Section;
139   }
140 
141   // Accessors.
getAsmPrinter()142   AsmPrinter* getAsmPrinter() const { return Asm; }
getUniqueID()143   unsigned getUniqueID() const { return UniqueID; }
getLanguage()144   uint16_t getLanguage() const { return CUNode->getSourceLanguage(); }
getCUNode()145   DICompileUnit getCUNode() const { return CUNode; }
getUnitDie()146   DIE &getUnitDie() { return UnitDie; }
147 
getDebugInfoOffset()148   unsigned getDebugInfoOffset() const { return DebugInfoOffset; }
setDebugInfoOffset(unsigned DbgInfoOff)149   void setDebugInfoOffset(unsigned DbgInfoOff) { DebugInfoOffset = DbgInfoOff; }
150 
151   /// hasContent - Return true if this compile unit has something to write out.
hasContent()152   bool hasContent() const { return !UnitDie.getChildren().empty(); }
153 
154   /// getParentContextString - Get a string containing the language specific
155   /// context for a global name.
156   std::string getParentContextString(DIScope Context) const;
157 
158   /// Add a new global name to the compile unit.
addGlobalName(StringRef Name,DIE & Die,DIScope Context)159   virtual void addGlobalName(StringRef Name, DIE &Die, DIScope Context) {}
160 
161   /// Add a new global type to the compile unit.
addGlobalType(DIType Ty,const DIE & Die,DIScope Context)162   virtual void addGlobalType(DIType Ty, const DIE &Die, DIScope Context) {}
163 
164   /// addAccelNamespace - Add a new name to the namespace accelerator table.
165   void addAccelNamespace(StringRef Name, const DIE &Die);
166 
167   /// getDIE - Returns the debug information entry map slot for the
168   /// specified debug variable. We delegate the request to DwarfDebug
169   /// when the MDNode can be part of the type system, since DIEs for
170   /// the type system can be shared across CUs and the mappings are
171   /// kept in DwarfDebug.
172   DIE *getDIE(DIDescriptor D) const;
173 
174   /// getDIELoc - Returns a fresh newly allocated DIELoc.
getDIELoc()175   DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc(); }
176 
177   /// insertDIE - Insert DIE into the map. We delegate the request to DwarfDebug
178   /// when the MDNode can be part of the type system, since DIEs for
179   /// the type system can be shared across CUs and the mappings are
180   /// kept in DwarfDebug.
181   void insertDIE(DIDescriptor Desc, DIE *D);
182 
183   /// addFlag - Add a flag that is true to the DIE.
184   void addFlag(DIE &Die, dwarf::Attribute Attribute);
185 
186   /// addUInt - Add an unsigned integer attribute data and value.
187   void addUInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
188                uint64_t Integer);
189 
190   void addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer);
191 
192   /// addSInt - Add an signed integer attribute data and value.
193   void addSInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
194                int64_t Integer);
195 
196   void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer);
197 
198   /// addString - Add a string attribute data and value.
199   void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
200 
201   /// addLabel - Add a Dwarf label attribute data and value.
202   void addLabel(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form,
203                 const MCSymbol *Label);
204 
205   void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label);
206 
207   /// addSectionOffset - Add an offset into a section attribute data and value.
208   ///
209   void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer);
210 
211   /// addOpAddress - Add a dwarf op address data and value using the
212   /// form given and an op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
213   void addOpAddress(DIELoc &Die, const MCSymbol *Label);
214 
215   /// addLabelDelta - Add a label delta attribute data and value.
216   void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
217                      const MCSymbol *Lo);
218 
219   /// addDIEEntry - Add a DIE attribute data and value.
220   void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry);
221 
222   /// addDIEEntry - Add a DIE attribute data and value.
223   void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry *Entry);
224 
225   void addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type);
226 
227   /// addBlock - Add block data.
228   void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block);
229 
230   /// addBlock - Add block data.
231   void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block);
232 
233   /// addSourceLine - Add location information to specified debug information
234   /// entry.
235   void addSourceLine(DIE &Die, unsigned Line, StringRef File,
236                      StringRef Directory);
237   void addSourceLine(DIE &Die, DIVariable V);
238   void addSourceLine(DIE &Die, DIGlobalVariable G);
239   void addSourceLine(DIE &Die, DISubprogram SP);
240   void addSourceLine(DIE &Die, DIType Ty);
241   void addSourceLine(DIE &Die, DINameSpace NS);
242   void addSourceLine(DIE &Die, DIObjCProperty Ty);
243 
244   /// addConstantValue - Add constant value entry in variable DIE.
245   void addConstantValue(DIE &Die, const MachineOperand &MO, DIType Ty);
246   void addConstantValue(DIE &Die, const ConstantInt *CI, DIType Ty);
247   void addConstantValue(DIE &Die, const APInt &Val, DIType Ty);
248   void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
249   void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
250 
251   /// addConstantFPValue - Add constant value entry in variable DIE.
252   void addConstantFPValue(DIE &Die, const MachineOperand &MO);
253   void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
254 
255   /// \brief Add a linkage name, if it isn't empty.
256   void addLinkageName(DIE &Die, StringRef LinkageName);
257 
258   /// addTemplateParams - Add template parameters in buffer.
259   void addTemplateParams(DIE &Buffer, DIArray TParams);
260 
261   /// \brief Add register operand.
262   /// \returns false if the register does not exist, e.g., because it was never
263   /// materialized.
264   bool addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
265                           unsigned SizeInBits = 0, unsigned OffsetInBits = 0);
266 
267   /// \brief Add register offset.
268   /// \returns false if the register does not exist, e.g., because it was never
269   /// materialized.
270   bool addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset);
271 
272   // FIXME: Should be reformulated in terms of addComplexAddress.
273   /// addBlockByrefAddress - Start with the address based on the location
274   /// provided, and generate the DWARF information necessary to find the
275   /// actual Block variable (navigating the Block struct) based on the
276   /// starting location.  Add the DWARF information to the die.  Obsolete,
277   /// please use addComplexAddress instead.
278   void addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
279                             dwarf::Attribute Attribute,
280                             const MachineLocation &Location);
281 
282   /// addType - Add a new type attribute to the specified entity. This takes
283   /// and attribute parameter because DW_AT_friend attributes are also
284   /// type references.
285   void addType(DIE &Entity, DIType Ty,
286                dwarf::Attribute Attribute = dwarf::DW_AT_type);
287 
288   /// getOrCreateNameSpace - Create a DIE for DINameSpace.
289   DIE *getOrCreateNameSpace(DINameSpace NS);
290 
291   /// getOrCreateSubprogramDIE - Create new DIE using SP.
292   DIE *getOrCreateSubprogramDIE(DISubprogram SP, bool Minimal = false);
293 
294   void applySubprogramAttributes(DISubprogram SP, DIE &SPDie,
295                                  bool Minimal = false);
296 
297   /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
298   /// given DIType.
299   DIE *getOrCreateTypeDIE(const MDNode *N);
300 
301   /// getOrCreateContextDIE - Get context owner's DIE.
302   DIE *createTypeDIE(DICompositeType Ty);
303 
304   /// getOrCreateContextDIE - Get context owner's DIE.
305   DIE *getOrCreateContextDIE(DIScope Context);
306 
307   /// constructContainingTypeDIEs - Construct DIEs for types that contain
308   /// vtables.
309   void constructContainingTypeDIEs();
310 
311   /// constructSubprogramArguments - Construct function argument DIEs.
312   void constructSubprogramArguments(DIE &Buffer, DITypeArray Args);
313 
314   /// Create a DIE with the given Tag, add the DIE to its parent, and
315   /// call insertDIE if MD is not null.
316   DIE &createAndAddDIE(unsigned Tag, DIE &Parent,
317                        DIDescriptor N = DIDescriptor());
318 
319   /// Compute the size of a header for this unit, not including the initial
320   /// length field.
getHeaderSize()321   virtual unsigned getHeaderSize() const {
322     return sizeof(int16_t) + // DWARF version number
323            sizeof(int32_t) + // Offset Into Abbrev. Section
324            sizeof(int8_t);   // Pointer Size (in bytes)
325   }
326 
327   /// Emit the header for this unit, not including the initial length field.
328   virtual void emitHeader(bool UseOffsets);
329 
330   virtual DwarfCompileUnit &getCU() = 0;
331 
332   /// constructTypeDIE - Construct type DIE from DICompositeType.
333   void constructTypeDIE(DIE &Buffer, DICompositeType CTy);
334 
335 protected:
336   /// getOrCreateStaticMemberDIE - Create new static data member DIE.
337   DIE *getOrCreateStaticMemberDIE(DIDerivedType DT);
338 
339   /// Look up the source ID with the given directory and source file names. If
340   /// none currently exists, create a new ID and insert it in the line table.
341   virtual unsigned getOrCreateSourceID(StringRef File, StringRef Directory) = 0;
342 
343   /// resolve - Look in the DwarfDebug map for the MDNode that
344   /// corresponds to the reference.
resolve(TypedDebugNodeRef<T> Ref)345   template <typename T> T *resolve(TypedDebugNodeRef<T> Ref) const {
346     return DD->resolve(Ref);
347   }
348 
349 private:
350   /// constructTypeDIE - Construct basic type die from DIBasicType.
351   void constructTypeDIE(DIE &Buffer, DIBasicType BTy);
352 
353   /// constructTypeDIE - Construct derived type die from DIDerivedType.
354   void constructTypeDIE(DIE &Buffer, DIDerivedType DTy);
355 
356   /// constructSubrangeDIE - Construct subrange DIE from DISubrange.
357   void constructSubrangeDIE(DIE &Buffer, DISubrange SR, DIE *IndexTy);
358 
359   /// constructArrayTypeDIE - Construct array type DIE from DICompositeType.
360   void constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy);
361 
362   /// constructEnumTypeDIE - Construct enum type DIE from DIEnumerator.
363   void constructEnumTypeDIE(DIE &Buffer, DICompositeType CTy);
364 
365   /// constructMemberDIE - Construct member DIE from DIDerivedType.
366   void constructMemberDIE(DIE &Buffer, DIDerivedType DT);
367 
368   /// constructTemplateTypeParameterDIE - Construct new DIE for the given
369   /// DITemplateTypeParameter.
370   void constructTemplateTypeParameterDIE(DIE &Buffer,
371                                          DITemplateTypeParameter TP);
372 
373   /// constructTemplateValueParameterDIE - Construct new DIE for the given
374   /// DITemplateValueParameter.
375   void constructTemplateValueParameterDIE(DIE &Buffer,
376                                           DITemplateValueParameter TVP);
377 
378   /// getLowerBoundDefault - Return the default lower bound for an array. If the
379   /// DWARF version doesn't handle the language, return -1.
380   int64_t getDefaultLowerBound() const;
381 
382   /// getDIEEntry - Returns the debug information entry for the specified
383   /// debug variable.
getDIEEntry(const MDNode * N)384   DIEEntry *getDIEEntry(const MDNode *N) const {
385     return MDNodeToDIEEntryMap.lookup(N);
386   }
387 
388   /// insertDIEEntry - Insert debug information entry into the map.
insertDIEEntry(const MDNode * N,DIEEntry * E)389   void insertDIEEntry(const MDNode *N, DIEEntry *E) {
390     MDNodeToDIEEntryMap.insert(std::make_pair(N, E));
391   }
392 
393   // getIndexTyDie - Get an anonymous type for index type.
394   DIE *getIndexTyDie();
395 
396   // setIndexTyDie - Set D as anonymous type for index which can be reused
397   // later.
setIndexTyDie(DIE * D)398   void setIndexTyDie(DIE *D) { IndexTyDie = D; }
399 
400   /// createDIEEntry - Creates a new DIEEntry to be a proxy for a debug
401   /// information entry.
402   DIEEntry *createDIEEntry(DIE &Entry);
403 
404   /// If this is a named finished type then include it in the list of types for
405   /// the accelerator tables.
406   void updateAcceleratorTables(DIScope Context, DIType Ty, const DIE &TyDIE);
407 
408   virtual bool isDwoUnit() const = 0;
409 };
410 
411 class DwarfTypeUnit : public DwarfUnit {
412   uint64_t TypeSignature;
413   const DIE *Ty;
414   DwarfCompileUnit &CU;
415   MCDwarfDwoLineTable *SplitLineTable;
416 
417   unsigned getOrCreateSourceID(StringRef File, StringRef Directory) override;
418   bool isDwoUnit() const override;
419 
420 public:
421   DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A,
422                 DwarfDebug *DW, DwarfFile *DWU,
423                 MCDwarfDwoLineTable *SplitLineTable = nullptr);
424 
setTypeSignature(uint64_t Signature)425   void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; }
getTypeSignature()426   uint64_t getTypeSignature() const { return TypeSignature; }
setType(const DIE * Ty)427   void setType(const DIE *Ty) { this->Ty = Ty; }
428 
429   /// Emit the header for this unit, not including the initial length field.
430   void emitHeader(bool UseOffsets) override;
getHeaderSize()431   unsigned getHeaderSize() const override {
432     return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature
433            sizeof(uint32_t);                               // Type DIE Offset
434   }
getCU()435   DwarfCompileUnit &getCU() override { return CU; }
436 };
437 } // end llvm namespace
438 #endif
439