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