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: 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 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: 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); } 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. 71 const DICompileUnit *CUNode; 72 73 // All DIEValues are allocated through this allocator. 74 BumpPtrAllocator DIEValueAllocator; 75 76 /// Target of Dwarf emission. 77 AsmPrinter *Asm; 78 79 // Holders for some common dwarf information. 80 DwarfDebug *DD; 81 DwarfFile *DU; 82 83 /// An anonymous type for index type. Owned by DIEUnit. 84 DIE *IndexTyDie; 85 86 /// Tracks the mapping of unit level debug information variables to debug 87 /// information entries. 88 DenseMap<const MDNode *, DIE *> MDNodeToDieMap; 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. 99 DenseMap<DIE *, const DINode *> ContainingTypeMap; 100 101 DwarfUnit(dwarf::Tag, const DICompileUnit *CU, AsmPrinter *A, DwarfDebug *DW, 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, 157 Optional<dwarf::Form> Form, uint64_t Integer); 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. 176 DIEValueList::value_iterator addLabel(DIEValueList &Die, 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); 275 276 bool useSegmentedStringOffsetsTable() const { 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; 368 DwarfCompileUnit &CU; 369 MCDwarfDwoLineTable *SplitLineTable; 370 371 unsigned getOrCreateSourceID(const DIFile *File) override; 372 bool isDwoUnit() const override; 373 374 public: 375 DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A, DwarfDebug *DW, 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 398