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