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