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 /// This dwarf writer support class manages information associated with a 67 /// source file. 68 class DwarfUnit { 69 protected: 70 /// A numeric ID unique among all CUs in the module 71 unsigned UniqueID; 72 73 /// MDNode for the compile unit. 74 const DICompileUnit *CUNode; 75 76 // All DIEValues are allocated through this allocator. 77 BumpPtrAllocator DIEValueAllocator; 78 79 /// Unit debug information entry. 80 DIE &UnitDie; 81 82 /// Offset of the UnitDie from beginning of debug info section. 83 unsigned DebugInfoOffset; 84 85 /// Target of Dwarf emission. 86 AsmPrinter *Asm; 87 88 // Holders for some common dwarf information. 89 DwarfDebug *DD; 90 DwarfFile *DU; 91 92 /// An anonymous type for index type. Owned by UnitDie. 93 DIE *IndexTyDie; 94 95 /// Tracks the mapping of unit level debug information variables to debug 96 /// information entries. 97 DenseMap<const MDNode *, DIE *> MDNodeToDieMap; 98 99 /// A list of all the DIEBlocks in use. 100 std::vector<DIEBlock *> DIEBlocks; 101 102 /// A list of all the DIELocs in use. 103 std::vector<DIELoc *> DIELocs; 104 105 /// This map is used to keep track of subprogram DIEs that need 106 /// DW_AT_containing_type attribute. This attribute points to a DIE that 107 /// corresponds to the MDNode mapped with the subprogram DIE. 108 DenseMap<DIE *, const DINode *> ContainingTypeMap; 109 110 /// The section this unit will be emitted in. 111 MCSection *Section; 112 113 DwarfUnit(unsigned UID, dwarf::Tag, const DICompileUnit *CU, AsmPrinter *A, 114 DwarfDebug *DW, DwarfFile *DWU); 115 116 /// Add a string attribute data and value. 117 /// 118 /// This is guaranteed to be in the local string pool instead of indirected. 119 void addLocalString(DIE &Die, dwarf::Attribute Attribute, StringRef Str); 120 121 void addIndexedString(DIE &Die, dwarf::Attribute Attribute, StringRef Str); 122 123 bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie); 124 125 public: 126 virtual ~DwarfUnit(); 127 128 void initSection(MCSection *Section); 129 getSection()130 MCSection *getSection() const { 131 assert(Section); 132 return Section; 133 } 134 135 // Accessors. getAsmPrinter()136 AsmPrinter* getAsmPrinter() const { return Asm; } getUniqueID()137 unsigned getUniqueID() const { return UniqueID; } getLanguage()138 uint16_t getLanguage() const { return CUNode->getSourceLanguage(); } getCUNode()139 const DICompileUnit *getCUNode() const { return CUNode; } getUnitDie()140 DIE &getUnitDie() { return UnitDie; } 141 getDebugInfoOffset()142 unsigned getDebugInfoOffset() const { return DebugInfoOffset; } setDebugInfoOffset(unsigned DbgInfoOff)143 void setDebugInfoOffset(unsigned DbgInfoOff) { DebugInfoOffset = DbgInfoOff; } 144 145 /// Return true if this compile unit has something to write out. hasContent()146 bool hasContent() const { return UnitDie.hasChildren(); } 147 148 /// Get string containing language specific context for a global name. 149 /// 150 /// Walks the metadata parent chain in a language specific manner (using the 151 /// compile unit language) and returns it as a string. This is done at the 152 /// metadata level because DIEs may not currently have been added to the 153 /// parent context and walking the DIEs looking for names is more expensive 154 /// than walking the metadata. 155 std::string getParentContextString(const DIScope *Context) const; 156 157 /// Add a new global name to the compile unit. addGlobalName(StringRef Name,DIE & Die,const DIScope * Context)158 virtual void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) { 159 } 160 161 /// Add a new global type to the compile unit. addGlobalType(const DIType * Ty,const DIE & Die,const DIScope * Context)162 virtual void addGlobalType(const DIType *Ty, const DIE &Die, 163 const DIScope *Context) {} 164 165 /// Add a new name to the namespace accelerator table. 166 void addAccelNamespace(StringRef Name, const DIE &Die); 167 168 /// Returns the DIE map slot for the specified debug variable. 169 /// 170 /// We delegate the request to DwarfDebug when the MDNode can be part of the 171 /// type system, since DIEs for the type system can be shared across CUs and 172 /// the mappings are kept in DwarfDebug. 173 DIE *getDIE(const DINode *D) const; 174 175 /// Returns a fresh newly allocated DIELoc. getDIELoc()176 DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc; } 177 178 /// Insert DIE into the map. 179 /// 180 /// We delegate the request to DwarfDebug when the MDNode can be part of the 181 /// type system, since DIEs for the type system can be shared across CUs and 182 /// the mappings are kept in DwarfDebug. 183 void insertDIE(const DINode *Desc, DIE *D); 184 185 /// Add a flag that is true to the DIE. 186 void addFlag(DIE &Die, dwarf::Attribute Attribute); 187 188 /// Add an unsigned integer attribute data and value. 189 void addUInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form, 190 uint64_t Integer); 191 192 void addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer); 193 194 /// Add an signed integer attribute data and value. 195 void addSInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form, 196 int64_t Integer); 197 198 void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer); 199 200 /// Add a string attribute data and value. 201 /// 202 /// We always emit a reference to the string pool instead of immediate 203 /// strings so that DIEs have more predictable sizes. In the case of split 204 /// dwarf we emit an index into another table which gets us the static offset 205 /// into the string table. 206 void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str); 207 208 /// Add a Dwarf label attribute data and value. 209 DIE::value_iterator addLabel(DIE &Die, dwarf::Attribute Attribute, 210 dwarf::Form Form, const MCSymbol *Label); 211 212 void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label); 213 214 /// Add an offset into a section attribute data and value. 215 void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer); 216 217 /// Add a dwarf op address data and value using the form given and an 218 /// op of either DW_FORM_addr or DW_FORM_GNU_addr_index. 219 void addOpAddress(DIELoc &Die, const MCSymbol *Label); 220 221 /// Add a label delta attribute data and value. 222 void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi, 223 const MCSymbol *Lo); 224 225 /// Add a DIE attribute data and value. 226 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry); 227 228 /// Add a DIE attribute data and value. 229 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry); 230 231 void addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type); 232 233 /// Add block data. 234 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block); 235 236 /// Add block data. 237 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block); 238 239 /// Add location information to specified debug information entry. 240 void addSourceLine(DIE &Die, unsigned Line, StringRef File, 241 StringRef Directory); 242 void addSourceLine(DIE &Die, const DILocalVariable *V); 243 void addSourceLine(DIE &Die, const DIGlobalVariable *G); 244 void addSourceLine(DIE &Die, const DISubprogram *SP); 245 void addSourceLine(DIE &Die, const DIType *Ty); 246 void addSourceLine(DIE &Die, const DINamespace *NS); 247 void addSourceLine(DIE &Die, const DIObjCProperty *Ty); 248 249 /// Add constant value entry in variable DIE. 250 void addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty); 251 void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty); 252 void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty); 253 void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned); 254 void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val); 255 256 /// Add constant value entry in variable DIE. 257 void addConstantFPValue(DIE &Die, const MachineOperand &MO); 258 void addConstantFPValue(DIE &Die, const ConstantFP *CFP); 259 260 /// Add a linkage name, if it isn't empty. 261 void addLinkageName(DIE &Die, StringRef LinkageName); 262 263 /// Add template parameters in buffer. 264 void addTemplateParams(DIE &Buffer, DINodeArray TParams); 265 266 /// Add register operand. 267 /// \returns false if the register does not exist, e.g., because it was never 268 /// materialized. 269 bool addRegisterOpPiece(DIELoc &TheDie, unsigned Reg, 270 unsigned SizeInBits = 0, unsigned OffsetInBits = 0); 271 272 /// Add register offset. 273 /// \returns false if the register does not exist, e.g., because it was never 274 /// materialized. 275 bool addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset); 276 277 // FIXME: Should be reformulated in terms of addComplexAddress. 278 /// Start with the address based on the location provided, and generate the 279 /// DWARF information necessary to find the actual Block variable (navigating 280 /// the Block struct) based on the starting location. Add the DWARF 281 /// information to the die. Obsolete, please use addComplexAddress instead. 282 void addBlockByrefAddress(const DbgVariable &DV, DIE &Die, 283 dwarf::Attribute Attribute, 284 const MachineLocation &Location); 285 286 /// Add a new type attribute to the specified entity. 287 /// 288 /// This takes and attribute parameter because DW_AT_friend attributes are 289 /// also type references. 290 void addType(DIE &Entity, const DIType *Ty, 291 dwarf::Attribute Attribute = dwarf::DW_AT_type); 292 293 DIE *getOrCreateNameSpace(const DINamespace *NS); 294 DIE *getOrCreateModule(const DIModule *M); 295 DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false); 296 297 void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie, 298 bool Minimal = false); 299 300 /// Find existing DIE or create new DIE for the given type. 301 DIE *getOrCreateTypeDIE(const MDNode *N); 302 303 /// Get context owner's DIE. 304 DIE *createTypeDIE(const DICompositeType *Ty); 305 306 /// Get context owner's DIE. 307 DIE *getOrCreateContextDIE(const DIScope *Context); 308 309 /// Construct DIEs for types that contain vtables. 310 void constructContainingTypeDIEs(); 311 312 /// Construct function argument DIEs. 313 void constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args); 314 315 /// Create a DIE with the given Tag, add the DIE to its parent, and 316 /// call insertDIE if MD is not null. 317 DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr); 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 void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy); 333 334 protected: 335 /// Create new static data member DIE. 336 DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT); 337 338 /// Look up the source ID with the given directory and source file names. If 339 /// none currently exists, create a new ID and insert it in the line table. 340 virtual unsigned getOrCreateSourceID(StringRef File, StringRef Directory) = 0; 341 342 /// Look in the DwarfDebug map for the MDNode that corresponds to the 343 /// reference. resolve(TypedDINodeRef<T> Ref)344 template <typename T> T *resolve(TypedDINodeRef<T> Ref) const { 345 return DD->resolve(Ref); 346 } 347 348 private: 349 void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy); 350 void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy); 351 void constructTypeDIE(DIE &Buffer, const DISubroutineType *DTy); 352 void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy); 353 void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy); 354 void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy); 355 void constructMemberDIE(DIE &Buffer, const DIDerivedType *DT); 356 void constructTemplateTypeParameterDIE(DIE &Buffer, 357 const DITemplateTypeParameter *TP); 358 void constructTemplateValueParameterDIE(DIE &Buffer, 359 const DITemplateValueParameter *TVP); 360 361 /// Return the default lower bound for an array. 362 /// 363 /// If the DWARF version doesn't handle the language, return -1. 364 int64_t getDefaultLowerBound() const; 365 366 /// Get an anonymous type for index type. 367 DIE *getIndexTyDie(); 368 369 /// Set D as anonymous type for index which can be reused later. setIndexTyDie(DIE * D)370 void setIndexTyDie(DIE *D) { IndexTyDie = D; } 371 372 /// If this is a named finished type then include it in the list of types for 373 /// the accelerator tables. 374 void updateAcceleratorTables(const DIScope *Context, const DIType *Ty, 375 const DIE &TyDIE); 376 377 virtual bool isDwoUnit() const = 0; 378 }; 379 380 class DwarfTypeUnit : public DwarfUnit { 381 uint64_t TypeSignature; 382 const DIE *Ty; 383 DwarfCompileUnit &CU; 384 MCDwarfDwoLineTable *SplitLineTable; 385 386 unsigned getOrCreateSourceID(StringRef File, StringRef Directory) override; 387 bool isDwoUnit() const override; 388 389 public: 390 DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A, 391 DwarfDebug *DW, DwarfFile *DWU, 392 MCDwarfDwoLineTable *SplitLineTable = nullptr); 393 setTypeSignature(uint64_t Signature)394 void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; } getTypeSignature()395 uint64_t getTypeSignature() const { return TypeSignature; } setType(const DIE * Ty)396 void setType(const DIE *Ty) { this->Ty = Ty; } 397 398 /// Emit the header for this unit, not including the initial length field. 399 void emitHeader(bool UseOffsets) override; getHeaderSize()400 unsigned getHeaderSize() const override { 401 return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature 402 sizeof(uint32_t); // Type DIE Offset 403 } getCU()404 DwarfCompileUnit &getCU() override { return CU; } 405 }; 406 } // end llvm namespace 407 #endif 408