1 //===-- llvm/CodeGen/DwarfUnit.h - Dwarf Compile Unit ---*- C++ -*--===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains support for writing dwarf compile unit. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H 14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H 15 16 #include "DwarfDebug.h" 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/ADT/Optional.h" 19 #include "llvm/CodeGen/AsmPrinter.h" 20 #include "llvm/CodeGen/DIE.h" 21 #include <string> 22 23 namespace llvm { 24 25 class ConstantFP; 26 class ConstantInt; 27 class DbgVariable; 28 class DwarfCompileUnit; 29 class MachineOperand; 30 class MCDwarfDwoLineTable; 31 class MCSymbol; 32 33 //===----------------------------------------------------------------------===// 34 /// This dwarf writer support class manages information associated with a 35 /// source file. 36 class DwarfUnit : public DIEUnit { 37 protected: 38 /// MDNode for the compile unit. 39 const DICompileUnit *CUNode; 40 41 // All DIEValues are allocated through this allocator. 42 BumpPtrAllocator DIEValueAllocator; 43 44 /// Target of Dwarf emission. 45 AsmPrinter *Asm; 46 47 /// Emitted at the end of the CU and used to compute the CU Length field. 48 MCSymbol *EndLabel = nullptr; 49 50 // Holders for some common dwarf information. 51 DwarfDebug *DD; 52 DwarfFile *DU; 53 54 /// An anonymous type for index type. Owned by DIEUnit. 55 DIE *IndexTyDie; 56 57 /// Tracks the mapping of unit level debug information variables to debug 58 /// information entries. 59 DenseMap<const MDNode *, DIE *> MDNodeToDieMap; 60 61 /// A list of all the DIEBlocks in use. 62 std::vector<DIEBlock *> DIEBlocks; 63 64 /// A list of all the DIELocs in use. 65 std::vector<DIELoc *> DIELocs; 66 67 /// This map is used to keep track of subprogram DIEs that need 68 /// DW_AT_containing_type attribute. This attribute points to a DIE that 69 /// corresponds to the MDNode mapped with the subprogram DIE. 70 DenseMap<DIE *, const DINode *> ContainingTypeMap; 71 72 DwarfUnit(dwarf::Tag, const DICompileUnit *Node, AsmPrinter *A, DwarfDebug *DW, 73 DwarfFile *DWU); 74 75 bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie); 76 77 bool isShareableAcrossCUs(const DINode *D) const; 78 79 template <typename T> 80 void addAttribute(DIEValueList &Die, dwarf::Attribute Attribute, 81 dwarf::Form Form, T &&Value) { 82 Die.addValue(DIEValueAllocator, 83 DIEValue(Attribute, Form, std::forward<T>(Value))); 84 } 85 86 public: 87 // Accessors. 88 AsmPrinter* getAsmPrinter() const { return Asm; } 89 MCSymbol *getEndLabel() const { return EndLabel; } 90 uint16_t getLanguage() const { return CUNode->getSourceLanguage(); } 91 const DICompileUnit *getCUNode() const { return CUNode; } 92 DwarfDebug &getDwarfDebug() const { return *DD; } 93 94 /// Return true if this compile unit has something to write out. 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. 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 void insertDIE(DIE *D); 132 133 /// Add a flag that is true to the DIE. 134 void addFlag(DIE &Die, dwarf::Attribute Attribute); 135 136 /// Add an unsigned integer attribute data and value. 137 void addUInt(DIEValueList &Die, dwarf::Attribute Attribute, 138 Optional<dwarf::Form> Form, uint64_t Integer); 139 140 void addUInt(DIEValueList &Block, dwarf::Form Form, uint64_t Integer); 141 142 /// Add an signed integer attribute data and value. 143 void addSInt(DIEValueList &Die, dwarf::Attribute Attribute, 144 Optional<dwarf::Form> Form, int64_t Integer); 145 146 void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer); 147 148 /// Add a string attribute data and value. 149 /// 150 /// We always emit a reference to the string pool instead of immediate 151 /// strings so that DIEs have more predictable sizes. In the case of split 152 /// dwarf we emit an index into another table which gets us the static offset 153 /// into the string table. 154 void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str); 155 156 /// Add a Dwarf label attribute data and value. 157 void addLabel(DIEValueList &Die, dwarf::Attribute Attribute, 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 void addPoolOpAddress(DIEValueList &Die, const MCSymbol *Label); 169 170 /// Add a label delta attribute data and value. 171 void addLabelDelta(DIEValueList &Die, dwarf::Attribute Attribute, 172 const MCSymbol *Hi, const MCSymbol *Lo); 173 174 /// Add a DIE attribute data and value. 175 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry); 176 177 /// Add a DIE attribute data and value. 178 void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry); 179 180 /// Add a type's DW_AT_signature and set the declaration flag. 181 void addDIETypeSignature(DIE &Die, uint64_t Signature); 182 183 /// Add block data. 184 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc); 185 186 /// Add block data. 187 void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block); 188 void addBlock(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form, 189 DIEBlock *Block); 190 191 /// Add location information to specified debug information entry. 192 void addSourceLine(DIE &Die, unsigned Line, const DIFile *File); 193 void addSourceLine(DIE &Die, const DILocalVariable *V); 194 void addSourceLine(DIE &Die, const DIGlobalVariable *G); 195 void addSourceLine(DIE &Die, const DISubprogram *SP); 196 void addSourceLine(DIE &Die, const DILabel *L); 197 void addSourceLine(DIE &Die, const DIType *Ty); 198 void addSourceLine(DIE &Die, const DIObjCProperty *Ty); 199 200 /// Add constant value entry in variable DIE. 201 void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty); 202 void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty); 203 void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned); 204 void addConstantValue(DIE &Die, uint64_t Val, const DIType *Ty); 205 void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val); 206 207 /// Add constant value entry in variable DIE. 208 void addConstantFPValue(DIE &Die, const ConstantFP *CFP); 209 210 /// Add a linkage name, if it isn't empty. 211 void addLinkageName(DIE &Die, StringRef LinkageName); 212 213 /// Add template parameters in buffer. 214 void addTemplateParams(DIE &Buffer, DINodeArray TParams); 215 216 /// Add thrown types. 217 void addThrownTypes(DIE &Die, DINodeArray ThrownTypes); 218 219 /// Add a new type attribute to the specified entity. 220 /// 221 /// This takes and attribute parameter because DW_AT_friend attributes are 222 /// also type references. 223 void addType(DIE &Entity, const DIType *Ty, 224 dwarf::Attribute Attribute = dwarf::DW_AT_type); 225 226 DIE *getOrCreateNameSpace(const DINamespace *NS); 227 DIE *getOrCreateModule(const DIModule *M); 228 DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false); 229 230 void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie, 231 bool SkipSPAttributes = false); 232 233 /// Creates type DIE with specific context. 234 DIE *createTypeDIE(const DIScope *Context, DIE &ContextDIE, const DIType *Ty); 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 Asm->getDwarfOffsetByteSize() + // 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 virtual DwarfCompileUnit &getCU() = 0; 276 277 void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy); 278 279 /// addSectionDelta - Add a label delta attribute data and value. 280 void addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi, 281 const MCSymbol *Lo); 282 283 /// Add a Dwarf section label attribute data and value. 284 void addSectionLabel(DIE &Die, dwarf::Attribute Attribute, 285 const MCSymbol *Label, const MCSymbol *Sec); 286 287 /// Get context owner's DIE. 288 DIE *createTypeDIE(const DICompositeType *Ty); 289 290 protected: 291 ~DwarfUnit(); 292 293 /// Create new static data member DIE. 294 DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT); 295 296 /// Look up the source ID for the given file. If none currently exists, 297 /// create a new ID and insert it in the line table. 298 virtual unsigned getOrCreateSourceID(const DIFile *File) = 0; 299 300 /// Emit the common part of the header for this unit. 301 void emitCommonHeader(bool UseOffsets, dwarf::UnitType UT); 302 303 private: 304 void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy); 305 void constructTypeDIE(DIE &Buffer, const DIStringType *BTy); 306 void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy); 307 void constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy); 308 void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy); 309 void constructGenericSubrangeDIE(DIE &Buffer, const DIGenericSubrange *SR, 310 DIE *IndexTy); 311 void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy); 312 void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy); 313 DIE &constructMemberDIE(DIE &Buffer, const DIDerivedType *DT); 314 void constructTemplateTypeParameterDIE(DIE &Buffer, 315 const DITemplateTypeParameter *TP); 316 void constructTemplateValueParameterDIE(DIE &Buffer, 317 const DITemplateValueParameter *TVP); 318 319 /// Return the default lower bound for an array. 320 /// 321 /// If the DWARF version doesn't handle the language, return -1. 322 int64_t getDefaultLowerBound() const; 323 324 /// Get an anonymous type for index type. 325 DIE *getIndexTyDie(); 326 327 /// Set D as anonymous type for index which can be reused later. 328 void setIndexTyDie(DIE *D) { IndexTyDie = D; } 329 330 virtual void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) = 0; 331 332 /// If this is a named finished type then include it in the list of types for 333 /// the accelerator tables. 334 void updateAcceleratorTables(const DIScope *Context, const DIType *Ty, 335 const DIE &TyDIE); 336 337 virtual bool isDwoUnit() const = 0; 338 const MCSymbol *getCrossSectionRelativeBaseAddress() const override; 339 }; 340 341 class DwarfTypeUnit final : public DwarfUnit { 342 uint64_t TypeSignature; 343 const DIE *Ty; 344 DwarfCompileUnit &CU; 345 MCDwarfDwoLineTable *SplitLineTable; 346 bool UsedLineTable = false; 347 348 unsigned getOrCreateSourceID(const DIFile *File) override; 349 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 350 bool isDwoUnit() const override; 351 352 public: 353 DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A, DwarfDebug *DW, 354 DwarfFile *DWU, MCDwarfDwoLineTable *SplitLineTable = nullptr); 355 356 void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; } 357 void setType(const DIE *Ty) { this->Ty = Ty; } 358 359 /// Emit the header for this unit, not including the initial length field. 360 void emitHeader(bool UseOffsets) override; 361 unsigned getHeaderSize() const override { 362 return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature 363 Asm->getDwarfOffsetByteSize(); // Type DIE Offset 364 } 365 void addGlobalName(StringRef Name, const DIE &Die, 366 const DIScope *Context) override; 367 void addGlobalType(const DIType *Ty, const DIE &Die, 368 const DIScope *Context) override; 369 DwarfCompileUnit &getCU() override { return CU; } 370 }; 371 } // end llvm namespace 372 #endif 373