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 //===----------------------------------------------------------------------===// 39 /// This dwarf writer support class manages information associated with a 40 /// source file. 41 class DwarfUnit : public DIEUnit { 42 protected: 43 /// MDNode for the compile unit. 44 const DICompileUnit *CUNode; 45 46 // All DIEValues are allocated through this allocator. 47 BumpPtrAllocator DIEValueAllocator; 48 49 /// Target of Dwarf emission. 50 AsmPrinter *Asm; 51 52 /// Emitted at the end of the CU and used to compute the CU Length field. 53 MCSymbol *EndLabel = nullptr; 54 55 // Holders for some common dwarf information. 56 DwarfDebug *DD; 57 DwarfFile *DU; 58 59 /// An anonymous type for index type. Owned by DIEUnit. 60 DIE *IndexTyDie; 61 62 /// Tracks the mapping of unit level debug information variables to debug 63 /// information entries. 64 DenseMap<const MDNode *, DIE *> MDNodeToDieMap; 65 66 /// A list of all the DIEBlocks in use. 67 std::vector<DIEBlock *> DIEBlocks; 68 69 /// A list of all the DIELocs in use. 70 std::vector<DIELoc *> DIELocs; 71 72 /// This map is used to keep track of subprogram DIEs that need 73 /// DW_AT_containing_type attribute. This attribute points to a DIE that 74 /// corresponds to the MDNode mapped with the subprogram DIE. 75 DenseMap<DIE *, const DINode *> ContainingTypeMap; 76 77 DwarfUnit(dwarf::Tag, const DICompileUnit *Node, AsmPrinter *A, DwarfDebug *DW, 78 DwarfFile *DWU); 79 80 bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie); 81 82 bool shareAcrossDWOCUs() const; 83 bool isShareableAcrossCUs(const DINode *D) const; 84 85 public: 86 // Accessors. getAsmPrinter()87 AsmPrinter* getAsmPrinter() const { return Asm; } getEndLabel()88 MCSymbol *getEndLabel() const { return EndLabel; } getLanguage()89 uint16_t getLanguage() const { return CUNode->getSourceLanguage(); } getCUNode()90 const DICompileUnit *getCUNode() const { return CUNode; } 91 getDwarfVersion()92 uint16_t getDwarfVersion() const { return DD->getDwarfVersion(); } 93 94 /// Return true if this compile unit has something to write out. hasContent()95 bool hasContent() const { return getUnitDie().hasChildren(); } 96 97 /// Get string containing language specific context for a global name. 98 /// 99 /// Walks the metadata parent chain in a language specific manner (using the 100 /// compile unit language) and returns it as a string. This is done at the 101 /// metadata level because DIEs may not currently have been added to the 102 /// parent context and walking the DIEs looking for names is more expensive 103 /// than walking the metadata. 104 std::string getParentContextString(const DIScope *Context) const; 105 106 /// Add a new global name to the compile unit. 107 virtual void addGlobalName(StringRef Name, const DIE &Die, 108 const DIScope *Context) = 0; 109 110 /// Add a new global type to the compile unit. 111 virtual void addGlobalType(const DIType *Ty, const DIE &Die, 112 const DIScope *Context) = 0; 113 114 /// Returns the DIE map slot for the specified debug variable. 115 /// 116 /// We delegate the request to DwarfDebug when the MDNode can be part of the 117 /// type system, since DIEs for the type system can be shared across CUs and 118 /// the mappings are kept in DwarfDebug. 119 DIE *getDIE(const DINode *D) const; 120 121 /// Returns a fresh newly allocated DIELoc. getDIELoc()122 DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc; } 123 124 /// Insert DIE into the map. 125 /// 126 /// We delegate the request to DwarfDebug when the MDNode can be part of the 127 /// type system, since DIEs for the type system can be shared across CUs and 128 /// the mappings are kept in DwarfDebug. 129 void insertDIE(const DINode *Desc, DIE *D); 130 131 /// Add a flag that is true to the DIE. 132 void addFlag(DIE &Die, dwarf::Attribute Attribute); 133 134 /// Add an unsigned integer attribute data and value. 135 void addUInt(DIEValueList &Die, dwarf::Attribute Attribute, 136 Optional<dwarf::Form> Form, uint64_t Integer); 137 138 void addUInt(DIEValueList &Block, dwarf::Form Form, uint64_t Integer); 139 140 /// Add an signed integer attribute data and value. 141 void addSInt(DIEValueList &Die, dwarf::Attribute Attribute, 142 Optional<dwarf::Form> Form, int64_t Integer); 143 144 void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer); 145 146 /// Add a string attribute data and value. 147 /// 148 /// We always emit a reference to the string pool instead of immediate 149 /// strings so that DIEs have more predictable sizes. In the case of split 150 /// dwarf we emit an index into another table which gets us the static offset 151 /// into the string table. 152 void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str); 153 154 /// Add a Dwarf label attribute data and value. 155 DIEValueList::value_iterator addLabel(DIEValueList &Die, 156 dwarf::Attribute Attribute, 157 dwarf::Form Form, 158 const MCSymbol *Label); 159 160 void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label); 161 162 /// Add an offset into a section attribute data and value. 163 void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer); 164 165 /// Add a dwarf op address data and value using the form given and an 166 /// op of either DW_FORM_addr or DW_FORM_GNU_addr_index. 167 void addOpAddress(DIELoc &Die, const MCSymbol *Sym); 168 169 /// Add a label delta attribute data and value. 170 void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi, 171 const MCSymbol *Lo); 172 173 /// Add a DIE attribute data and value. 174 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry); 175 176 /// Add a DIE attribute data and value. 177 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry); 178 179 /// Add a type's DW_AT_signature and set the declaration flag. 180 void addDIETypeSignature(DIE &Die, uint64_t Signature); 181 182 /// Add block data. 183 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc); 184 185 /// Add block data. 186 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block); 187 188 /// Add location information to specified debug information entry. 189 void addSourceLine(DIE &Die, unsigned Line, const DIFile *File); 190 void addSourceLine(DIE &Die, const DILocalVariable *V); 191 void addSourceLine(DIE &Die, const DIGlobalVariable *G); 192 void addSourceLine(DIE &Die, const DISubprogram *SP); 193 void addSourceLine(DIE &Die, const DILabel *L); 194 void addSourceLine(DIE &Die, const DIType *Ty); 195 void addSourceLine(DIE &Die, const DIObjCProperty *Ty); 196 197 /// Add constant value entry in variable DIE. 198 void addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty); 199 void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty); 200 void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty); 201 void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned); 202 void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val); 203 204 /// Add constant value entry in variable DIE. 205 void addConstantFPValue(DIE &Die, const MachineOperand &MO); 206 void addConstantFPValue(DIE &Die, const ConstantFP *CFP); 207 208 /// Add a linkage name, if it isn't empty. 209 void addLinkageName(DIE &Die, StringRef LinkageName); 210 211 /// Add template parameters in buffer. 212 void addTemplateParams(DIE &Buffer, DINodeArray TParams); 213 214 /// Add thrown types. 215 void addThrownTypes(DIE &Die, DINodeArray ThrownTypes); 216 217 // FIXME: Should be reformulated in terms of addComplexAddress. 218 /// Start with the address based on the location provided, and generate the 219 /// DWARF information necessary to find the actual Block variable (navigating 220 /// the Block struct) based on the starting location. Add the DWARF 221 /// information to the die. Obsolete, please use addComplexAddress instead. 222 void addBlockByrefAddress(const DbgVariable &DV, DIE &Die, 223 dwarf::Attribute Attribute, 224 const MachineLocation &Location); 225 226 /// Add a new type attribute to the specified entity. 227 /// 228 /// This takes and attribute parameter because DW_AT_friend attributes are 229 /// also type references. 230 void addType(DIE &Entity, const DIType *Ty, 231 dwarf::Attribute Attribute = dwarf::DW_AT_type); 232 233 DIE *getOrCreateNameSpace(const DINamespace *NS); 234 DIE *getOrCreateModule(const DIModule *M); 235 DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false); 236 237 void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie, 238 bool SkipSPAttributes = false); 239 240 /// Find existing DIE or create new DIE for the given type. 241 DIE *getOrCreateTypeDIE(const MDNode *TyNode); 242 243 /// Get context owner's DIE. 244 DIE *getOrCreateContextDIE(const DIScope *Context); 245 246 /// Construct DIEs for types that contain vtables. 247 void constructContainingTypeDIEs(); 248 249 /// Construct function argument DIEs. 250 void constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args); 251 252 /// Create a DIE with the given Tag, add the DIE to its parent, and 253 /// call insertDIE if MD is not null. 254 DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr); 255 useSegmentedStringOffsetsTable()256 bool useSegmentedStringOffsetsTable() const { 257 return DD->useSegmentedStringOffsetsTable(); 258 } 259 260 /// Compute the size of a header for this unit, not including the initial 261 /// length field. getHeaderSize()262 virtual unsigned getHeaderSize() const { 263 return sizeof(int16_t) + // DWARF version number 264 sizeof(int32_t) + // Offset Into Abbrev. Section 265 sizeof(int8_t) + // Pointer Size (in bytes) 266 (DD->getDwarfVersion() >= 5 ? sizeof(int8_t) 267 : 0); // DWARF v5 unit type 268 } 269 270 /// Emit the header for this unit, not including the initial length field. 271 virtual void emitHeader(bool UseOffsets) = 0; 272 273 /// Add the DW_AT_str_offsets_base attribute to the unit DIE. 274 void addStringOffsetsStart(); 275 276 /// Add the DW_AT_rnglists_base attribute to the unit DIE. 277 void addRnglistsBase(); 278 279 /// Add the DW_AT_loclists_base attribute to the unit DIE. 280 void addLoclistsBase(); 281 282 virtual DwarfCompileUnit &getCU() = 0; 283 284 void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy); 285 286 /// addSectionDelta - Add a label delta attribute data and value. 287 DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute, 288 const MCSymbol *Hi, const MCSymbol *Lo); 289 290 /// Add a Dwarf section label attribute data and value. 291 DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute, 292 const MCSymbol *Label, 293 const MCSymbol *Sec); 294 295 /// If the \p File has an MD5 checksum, return it as an MD5Result 296 /// allocated in the MCContext. 297 MD5::MD5Result *getMD5AsBytes(const DIFile *File) const; 298 299 protected: 300 ~DwarfUnit(); 301 302 /// Create new static data member DIE. 303 DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT); 304 305 /// Look up the source ID for the given file. If none currently exists, 306 /// create a new ID and insert it in the line table. 307 virtual unsigned getOrCreateSourceID(const DIFile *File) = 0; 308 309 /// Look in the DwarfDebug map for the MDNode that corresponds to the 310 /// reference. resolve(TypedDINodeRef<T> Ref)311 template <typename T> T *resolve(TypedDINodeRef<T> Ref) const { 312 return Ref.resolve(); 313 } 314 315 /// If this is a named finished type then include it in the list of types for 316 /// the accelerator tables. 317 void updateAcceleratorTables(const DIScope *Context, const DIType *Ty, 318 const DIE &TyDIE); 319 320 /// Emit the common part of the header for this unit. 321 void emitCommonHeader(bool UseOffsets, dwarf::UnitType UT); 322 323 private: 324 void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy); 325 void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy); 326 void constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy); 327 void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy); 328 void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy); 329 void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy); 330 DIE &constructMemberDIE(DIE &Buffer, const DIDerivedType *DT); 331 void constructTemplateTypeParameterDIE(DIE &Buffer, 332 const DITemplateTypeParameter *TP); 333 void constructTemplateValueParameterDIE(DIE &Buffer, 334 const DITemplateValueParameter *TVP); 335 336 /// Return the default lower bound for an array. 337 /// 338 /// If the DWARF version doesn't handle the language, return -1. 339 int64_t getDefaultLowerBound() const; 340 341 /// Get an anonymous type for index type. 342 DIE *getIndexTyDie(); 343 344 /// Set D as anonymous type for index which can be reused later. setIndexTyDie(DIE * D)345 void setIndexTyDie(DIE *D) { IndexTyDie = D; } 346 347 virtual bool isDwoUnit() const = 0; 348 const MCSymbol *getCrossSectionRelativeBaseAddress() const override; 349 }; 350 351 class DwarfTypeUnit final : public DwarfUnit { 352 uint64_t TypeSignature; 353 const DIE *Ty; 354 DwarfCompileUnit &CU; 355 MCDwarfDwoLineTable *SplitLineTable; 356 bool UsedLineTable = false; 357 358 unsigned getOrCreateSourceID(const DIFile *File) override; 359 bool isDwoUnit() const override; 360 361 public: 362 DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A, DwarfDebug *DW, 363 DwarfFile *DWU, MCDwarfDwoLineTable *SplitLineTable = nullptr); 364 setTypeSignature(uint64_t Signature)365 void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; } setType(const DIE * Ty)366 void setType(const DIE *Ty) { this->Ty = Ty; } 367 368 /// Get context owner's DIE. 369 DIE *createTypeDIE(const DICompositeType *Ty); 370 371 /// Emit the header for this unit, not including the initial length field. 372 void emitHeader(bool UseOffsets) override; getHeaderSize()373 unsigned getHeaderSize() const override { 374 return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature 375 sizeof(uint32_t); // Type DIE Offset 376 } 377 void addGlobalName(StringRef Name, const DIE &Die, 378 const DIScope *Context) override; 379 void addGlobalType(const DIType *Ty, const DIE &Die, 380 const DIScope *Context) override; getCU()381 DwarfCompileUnit &getCU() override { return CU; } 382 }; 383 } // end llvm namespace 384 #endif 385