1 //===- llvm/CodeGen/DwarfCompileUnit.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_DWARFCOMPILEUNIT_H 14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 15 16 #include "DwarfDebug.h" 17 #include "DwarfUnit.h" 18 #include "llvm/ADT/ArrayRef.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/ADT/StringMap.h" 22 #include "llvm/ADT/StringRef.h" 23 #include "llvm/BinaryFormat/Dwarf.h" 24 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h" 25 #include "llvm/CodeGen/LexicalScopes.h" 26 #include "llvm/IR/DebugInfoMetadata.h" 27 #include "llvm/Support/Casting.h" 28 #include <cstdint> 29 #include <memory> 30 31 namespace llvm { 32 33 class AsmPrinter; 34 class DIE; 35 class DIELoc; 36 class DIEValueList; 37 class DwarfFile; 38 class GlobalVariable; 39 class MCExpr; 40 class MCSymbol; 41 class MDNode; 42 43 enum class UnitKind { Skeleton, Full }; 44 45 class DwarfCompileUnit final : public DwarfUnit { 46 bool HasRangeLists = false; 47 48 /// The start of the unit line section, this is also 49 /// reused in appyStmtList. 50 MCSymbol *LineTableStartSym; 51 52 /// Skeleton unit associated with this unit. 53 DwarfCompileUnit *Skeleton = nullptr; 54 55 /// The start of the unit macro info within macro section. 56 MCSymbol *MacroLabelBegin; 57 58 /// GlobalNames - A map of globally visible named entities for this unit. 59 StringMap<const DIE *> GlobalNames; 60 61 /// GlobalTypes - A map of globally visible types for this unit. 62 StringMap<const DIE *> GlobalTypes; 63 64 // List of ranges for a given compile unit. 65 SmallVector<RangeSpan, 2> CURanges; 66 67 // The base address of this unit, if any. Used for relative references in 68 // ranges/locs. 69 const MCSymbol *BaseAddress = nullptr; 70 71 using MDNodeSetVector = 72 SetVector<const MDNode *, SmallVector<const MDNode *, 4>, 73 SmallPtrSet<const MDNode *, 4>>; 74 75 // List of entities (either static locals, types or imports) that 76 // belong to subprograms within this CU. 77 MDNodeSetVector DeferredLocalDecls; 78 79 // List of concrete lexical block scopes belong to subprograms within this CU. 80 DenseMap<const DILocalScope *, DIE *> LexicalBlockDIEs; 81 82 // List of abstract local scopes (either DISubprogram or DILexicalBlock). 83 DenseMap<const DILocalScope *, DIE *> AbstractLocalScopeDIEs; 84 85 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities; 86 87 /// DWO ID for correlating skeleton and split units. 88 uint64_t DWOId = 0; 89 90 const DIFile *LastFile = nullptr; 91 unsigned LastFileID; 92 93 /// \anchor applyConcreteDbgVariableAttribute 94 /// \name applyConcreteDbgVariableAttribute 95 /// Overload set which applies attributes to \c VariableDie based on 96 /// the active variant of \c DV, which is passed as the first argument. 97 ///@{ 98 99 /// See \ref applyConcreteDbgVariableAttribute 100 void applyConcreteDbgVariableAttributes(const Loc::Single &Single, 101 const DbgVariable &DV, 102 DIE &VariableDie); 103 /// See \ref applyConcreteDbgVariableAttribute 104 void applyConcreteDbgVariableAttributes(const Loc::Multi &Multi, 105 const DbgVariable &DV, 106 DIE &VariableDie); 107 /// See \ref applyConcreteDbgVariableAttribute 108 void applyConcreteDbgVariableAttributes(const Loc::MMI &MMI, 109 const DbgVariable &DV, 110 DIE &VariableDie); 111 /// See \ref applyConcreteDbgVariableAttribute 112 void applyConcreteDbgVariableAttributes(const Loc::EntryValue &EntryValue, 113 const DbgVariable &DV, 114 DIE &VariableDie); 115 /// See \ref applyConcreteDbgVariableAttribute 116 void applyConcreteDbgVariableAttributes(const std::monostate &, 117 const DbgVariable &DV, 118 DIE &VariableDie); 119 120 ///@} 121 122 bool isDwoUnit() const override; 123 124 DenseMap<const DILocalScope *, DIE *> &getAbstractScopeDIEs() { 125 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 126 return AbstractLocalScopeDIEs; 127 return DU->getAbstractScopeDIEs(); 128 } 129 130 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() { 131 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 132 return AbstractEntities; 133 return DU->getAbstractEntities(); 134 } 135 136 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 137 138 /// Add info for Wasm-global-based relocation. 139 void addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName, 140 uint64_t GlobalIndex); 141 142 public: 143 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A, 144 DwarfDebug *DW, DwarfFile *DWU, 145 UnitKind Kind = UnitKind::Full); 146 147 bool hasRangeLists() const { return HasRangeLists; } 148 149 DwarfCompileUnit *getSkeleton() const { 150 return Skeleton; 151 } 152 153 bool includeMinimalInlineScopes() const; 154 155 bool emitFuncLineTableOffsets() const; 156 157 void initStmtList(); 158 159 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE. 160 void applyStmtList(DIE &D); 161 162 /// Get line table start symbol for this unit. 163 MCSymbol *getLineTableStartSym() const { return LineTableStartSym; } 164 165 /// A pair of GlobalVariable and DIExpression. 166 struct GlobalExpr { 167 const GlobalVariable *Var; 168 const DIExpression *Expr; 169 }; 170 171 struct BaseTypeRef { 172 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) : 173 BitSize(BitSize), Encoding(Encoding) {} 174 unsigned BitSize; 175 dwarf::TypeKind Encoding; 176 DIE *Die = nullptr; 177 }; 178 179 std::vector<BaseTypeRef> ExprRefedBaseTypes; 180 181 /// Get or create global variable DIE. 182 DIE * 183 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV, 184 ArrayRef<GlobalExpr> GlobalExprs); 185 186 DIE *getOrCreateCommonBlock(const DICommonBlock *CB, 187 ArrayRef<GlobalExpr> GlobalExprs); 188 189 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV, 190 ArrayRef<GlobalExpr> GlobalExprs); 191 192 /// addLabelAddress - Add a dwarf label attribute data and value using 193 /// either DW_FORM_addr or DW_FORM_GNU_addr_index. 194 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute, 195 const MCSymbol *Label); 196 197 /// addLocalLabelAddress - Add a dwarf label attribute data and value using 198 /// DW_FORM_addr only. 199 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute, 200 const MCSymbol *Label); 201 202 DwarfCompileUnit &getCU() override { return *this; } 203 204 unsigned getOrCreateSourceID(const DIFile *File) override; 205 206 /// addRange - Add an address range to the list of ranges for this unit. 207 void addRange(RangeSpan Range); 208 209 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End); 210 211 /// Find DIE for the given subprogram and attach appropriate 212 /// DW_AT_low_pc, DW_AT_high_pc and DW_AT_LLVM_stmt_sequence attributes. 213 /// If there are global variables in this scope then create and insert DIEs 214 /// for these variables. 215 DIE &updateSubprogramScopeDIE(const DISubprogram *SP, MCSymbol *LineTableSym); 216 217 void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE); 218 219 /// A helper function to construct a RangeSpanList for a given 220 /// lexical scope. 221 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range); 222 223 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges); 224 225 void attachRangesOrLowHighPC(DIE &D, 226 const SmallVectorImpl<InsnRange> &Ranges); 227 228 /// This scope represents an inlined body of a function. Construct a 229 /// DIE to represent this concrete inlined copy of the function. 230 DIE *constructInlinedScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE); 231 232 /// Construct new DW_TAG_lexical_block for this scope and 233 /// attach DW_AT_low_pc/DW_AT_high_pc labels. 234 DIE *constructLexicalScopeDIE(LexicalScope *Scope); 235 236 /// Get a DIE for the given DILexicalBlock. 237 /// Note that this function assumes that the DIE has been already created 238 /// and it's an error, if it hasn't. 239 DIE *getLexicalBlockDIE(const DILexicalBlock *LB); 240 241 /// Construct a DIE for the given DbgVariable. 242 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false); 243 244 /// Convenience overload which writes the DIE pointer into an out variable 245 /// ObjectPointer in addition to returning it. 246 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope, 247 DIE *&ObjectPointer); 248 249 /// Construct a DIE for the given DbgLabel. 250 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope); 251 252 void createBaseTypeDIEs(); 253 254 /// Construct a DIE for a given scope. 255 /// This instance of 'getOrCreateContextDIE()' can handle DILocalScope. 256 DIE *getOrCreateContextDIE(const DIScope *Ty) override; 257 258 /// Construct a DIE for this subprogram scope. 259 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope, 260 MCSymbol *LineTableSym); 261 262 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE); 263 264 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope); 265 266 /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location 267 /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info. 268 bool useGNUAnalogForDwarf5Feature() const; 269 270 /// This takes a DWARF 5 tag and returns it or a GNU analog. 271 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const; 272 273 /// This takes a DWARF 5 attribute and returns it or a GNU analog. 274 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const; 275 276 /// This takes a DWARF 5 location atom and either returns it or a GNU analog. 277 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const; 278 279 /// Construct a call site entry DIE describing a call within \p Scope to a 280 /// callee described by \p CalleeSP. 281 /// \p IsTail specifies whether the call is a tail call. 282 /// \p PCAddr points to the PC value after the call instruction. 283 /// \p CallAddr points to the PC value at the call instruction (or is null). 284 /// \p CallReg is a register location for an indirect call. For direct calls 285 /// the \p CallReg is set to 0. 286 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP, 287 bool IsTail, const MCSymbol *PCAddr, 288 const MCSymbol *CallAddr, unsigned CallReg); 289 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params 290 /// were collected by the \ref collectCallSiteParameters. 291 /// Note: The order of parameters does not matter, since debuggers recognize 292 /// call site parameters by the DW_AT_location attribute. 293 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE, 294 SmallVector<DbgCallSiteParam, 4> &Params); 295 296 /// Get or create a DIE for an imported entity. 297 DIE *getOrCreateImportedEntityDIE(const DIImportedEntity *IE); 298 DIE *constructImportedEntityDIE(const DIImportedEntity *IE); 299 300 void finishSubprogramDefinition(const DISubprogram *SP); 301 void finishEntityDefinition(const DbgEntity *Entity); 302 303 /// Find abstract variable associated with Var. 304 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 305 DbgEntity *getExistingAbstractEntity(const DINode *Node); 306 void createAbstractEntity(const DINode *Node, LexicalScope *Scope); 307 308 /// Set the skeleton unit associated with this unit. 309 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; } 310 311 unsigned getHeaderSize() const override { 312 // DWARF v5 added the DWO ID to the header for split/skeleton units. 313 unsigned DWOIdSize = 314 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t) 315 : 0; 316 return DwarfUnit::getHeaderSize() + DWOIdSize; 317 } 318 unsigned getLength() { 319 return Asm->getUnitLengthFieldByteSize() + // Length field 320 getHeaderSize() + getUnitDie().getSize(); 321 } 322 323 void emitHeader(bool UseOffsets) override; 324 325 /// Add the DW_AT_addr_base attribute to the unit DIE. 326 void addAddrTableBase(); 327 328 MCSymbol *getMacroLabelBegin() const { 329 return MacroLabelBegin; 330 } 331 332 /// Add a new global name to the compile unit. 333 void addGlobalName(StringRef Name, const DIE &Die, 334 const DIScope *Context) override; 335 336 /// Add a new global name present in a type unit to this compile unit. 337 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context); 338 339 /// Add a new global type to the compile unit. 340 void addGlobalTypeImpl(const DIType *Ty, const DIE &Die, 341 const DIScope *Context) override; 342 343 /// Add a new global type present in a type unit to this compile unit. 344 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context); 345 346 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; } 347 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; } 348 349 /// Add DW_AT_location attribute for a DbgVariable based on provided 350 /// MachineLocation. 351 void addVariableAddress(const DbgVariable &DV, DIE &Die, 352 MachineLocation Location); 353 /// Add an address attribute to a die based on the location provided. 354 void addAddress(DIE &Die, dwarf::Attribute Attribute, 355 const MachineLocation &Location); 356 357 /// Start with the address based on the location provided, and generate the 358 /// DWARF information necessary to find the actual variable (navigating the 359 /// extra location information encoded in the type) based on the starting 360 /// location. Add the DWARF information to the die. 361 void addComplexAddress(const DIExpression *DIExpr, DIE &Die, 362 dwarf::Attribute Attribute, 363 const MachineLocation &Location); 364 365 /// Add a Dwarf loclistptr attribute data and value. 366 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index); 367 368 /// Add attributes to \p Var which reflect the common attributes of \p 369 /// VariableDie, namely those which are not dependant on the active variant. 370 void applyCommonDbgVariableAttributes(const DbgVariable &Var, 371 DIE &VariableDie); 372 373 /// Add a Dwarf expression attribute data and value. 374 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr); 375 376 void applySubprogramAttributesToDefinition(const DISubprogram *SP, 377 DIE &SPDie); 378 379 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie); 380 381 /// getRanges - Get the list of ranges for this unit. 382 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; } 383 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); } 384 385 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; } 386 const MCSymbol *getBaseAddress() const { return BaseAddress; } 387 388 uint64_t getDWOId() const { return DWOId; } 389 void setDWOId(uint64_t DwoId) { DWOId = DwoId; } 390 391 bool hasDwarfPubSections() const; 392 393 void addBaseTypeRef(DIEValueList &Die, int64_t Idx); 394 395 MDNodeSetVector &getDeferredLocalDecls() { return DeferredLocalDecls; } 396 }; 397 398 } // end namespace llvm 399 400 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 401