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 <algorithm> 29 #include <cassert> 30 #include <cstdint> 31 #include <memory> 32 33 namespace llvm { 34 35 class AsmPrinter; 36 class DIE; 37 class DIELoc; 38 class DIEValueList; 39 class DwarfFile; 40 class GlobalVariable; 41 class MCExpr; 42 class MCSymbol; 43 class MDNode; 44 45 enum class UnitKind { Skeleton, Full }; 46 47 class DwarfCompileUnit final : public DwarfUnit { 48 /// A numeric ID unique among all CUs in the module 49 unsigned UniqueID; 50 bool HasRangeLists = false; 51 52 /// The start of the unit line section, this is also 53 /// reused in appyStmtList. 54 MCSymbol *LineTableStartSym; 55 56 /// Skeleton unit associated with this unit. 57 DwarfCompileUnit *Skeleton = nullptr; 58 59 /// The start of the unit within its section. 60 MCSymbol *LabelBegin = nullptr; 61 62 /// The start of the unit macro info within macro section. 63 MCSymbol *MacroLabelBegin; 64 65 using ImportedEntityList = SmallVector<const MDNode *, 8>; 66 using ImportedEntityMap = DenseMap<const MDNode *, ImportedEntityList>; 67 68 ImportedEntityMap ImportedEntities; 69 70 /// GlobalNames - A map of globally visible named entities for this unit. 71 StringMap<const DIE *> GlobalNames; 72 73 /// GlobalTypes - A map of globally visible types for this unit. 74 StringMap<const DIE *> GlobalTypes; 75 76 // List of ranges for a given compile unit. 77 SmallVector<RangeSpan, 2> CURanges; 78 79 // The base address of this unit, if any. Used for relative references in 80 // ranges/locs. 81 const MCSymbol *BaseAddress = nullptr; 82 83 DenseMap<const MDNode *, DIE *> AbstractSPDies; 84 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities; 85 86 /// DWO ID for correlating skeleton and split units. 87 uint64_t DWOId = 0; 88 89 /// Construct a DIE for the given DbgVariable without initializing the 90 /// DbgVariable's DIE reference. 91 DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract); 92 93 bool isDwoUnit() const override; 94 getAbstractSPDies()95 DenseMap<const MDNode *, DIE *> &getAbstractSPDies() { 96 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 97 return AbstractSPDies; 98 return DU->getAbstractSPDies(); 99 } 100 getAbstractEntities()101 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() { 102 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 103 return AbstractEntities; 104 return DU->getAbstractEntities(); 105 } 106 107 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 108 109 public: 110 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A, 111 DwarfDebug *DW, DwarfFile *DWU, 112 UnitKind Kind = UnitKind::Full); 113 hasRangeLists()114 bool hasRangeLists() const { return HasRangeLists; } getUniqueID()115 unsigned getUniqueID() const { return UniqueID; } 116 getSkeleton()117 DwarfCompileUnit *getSkeleton() const { 118 return Skeleton; 119 } 120 121 bool includeMinimalInlineScopes() const; 122 123 void initStmtList(); 124 125 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE. 126 void applyStmtList(DIE &D); 127 128 /// Get line table start symbol for this unit. getLineTableStartSym()129 MCSymbol *getLineTableStartSym() const { return LineTableStartSym; } 130 131 /// A pair of GlobalVariable and DIExpression. 132 struct GlobalExpr { 133 const GlobalVariable *Var; 134 const DIExpression *Expr; 135 }; 136 137 struct BaseTypeRef { BaseTypeRefBaseTypeRef138 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) : 139 BitSize(BitSize), Encoding(Encoding) {} 140 unsigned BitSize; 141 dwarf::TypeKind Encoding; 142 DIE *Die = nullptr; 143 }; 144 145 std::vector<BaseTypeRef> ExprRefedBaseTypes; 146 147 /// Get or create global variable DIE. 148 DIE * 149 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV, 150 ArrayRef<GlobalExpr> GlobalExprs); 151 152 DIE *getOrCreateCommonBlock(const DICommonBlock *CB, 153 ArrayRef<GlobalExpr> GlobalExprs); 154 155 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV, 156 ArrayRef<GlobalExpr> GlobalExprs); 157 158 /// addLabelAddress - Add a dwarf label attribute data and value using 159 /// either DW_FORM_addr or DW_FORM_GNU_addr_index. 160 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute, 161 const MCSymbol *Label); 162 163 /// addLocalLabelAddress - Add a dwarf label attribute data and value using 164 /// DW_FORM_addr only. 165 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute, 166 const MCSymbol *Label); 167 getCU()168 DwarfCompileUnit &getCU() override { return *this; } 169 170 unsigned getOrCreateSourceID(const DIFile *File) override; 171 addImportedEntity(const DIImportedEntity * IE)172 void addImportedEntity(const DIImportedEntity* IE) { 173 DIScope *Scope = IE->getScope(); 174 assert(Scope && "Invalid Scope encoding!"); 175 if (!isa<DILocalScope>(Scope)) 176 // No need to add imported enities that are not local declaration. 177 return; 178 179 auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope(); 180 ImportedEntities[LocalScope].push_back(IE); 181 } 182 183 /// addRange - Add an address range to the list of ranges for this unit. 184 void addRange(RangeSpan Range); 185 186 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End); 187 188 /// Find DIE for the given subprogram and attach appropriate 189 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global 190 /// variables in this scope then create and insert DIEs for these 191 /// variables. 192 DIE &updateSubprogramScopeDIE(const DISubprogram *SP); 193 194 void constructScopeDIE(LexicalScope *Scope, 195 SmallVectorImpl<DIE *> &FinalChildren); 196 197 /// A helper function to construct a RangeSpanList for a given 198 /// lexical scope. 199 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range); 200 201 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges); 202 203 void attachRangesOrLowHighPC(DIE &D, 204 const SmallVectorImpl<InsnRange> &Ranges); 205 206 /// This scope represents inlined body of a function. Construct 207 /// DIE to represent this concrete inlined copy of the function. 208 DIE *constructInlinedScopeDIE(LexicalScope *Scope); 209 210 /// Construct new DW_TAG_lexical_block for this scope and 211 /// attach DW_AT_low_pc/DW_AT_high_pc labels. 212 DIE *constructLexicalScopeDIE(LexicalScope *Scope); 213 214 /// constructVariableDIE - Construct a DIE for the given DbgVariable. 215 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false); 216 217 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope, 218 DIE *&ObjectPointer); 219 220 /// Construct a DIE for the given DbgLabel. 221 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope); 222 223 /// A helper function to create children of a Scope DIE. 224 DIE *createScopeChildrenDIE(LexicalScope *Scope, 225 SmallVectorImpl<DIE *> &Children, 226 bool *HasNonScopeChildren = nullptr); 227 228 void createBaseTypeDIEs(); 229 230 /// Construct a DIE for this subprogram scope. 231 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, 232 LexicalScope *Scope); 233 234 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE); 235 236 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope); 237 238 /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location 239 /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info. 240 bool useGNUAnalogForDwarf5Feature() const; 241 242 /// This takes a DWARF 5 tag and returns it or a GNU analog. 243 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const; 244 245 /// This takes a DWARF 5 attribute and returns it or a GNU analog. 246 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const; 247 248 /// This takes a DWARF 5 location atom and either returns it or a GNU analog. 249 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const; 250 251 /// Construct a call site entry DIE describing a call within \p Scope to a 252 /// callee described by \p CalleeDIE. 253 /// \p CalleeDIE is a declaration or definition subprogram DIE for the callee. 254 /// For indirect calls \p CalleeDIE is set to nullptr. 255 /// \p IsTail specifies whether the call is a tail call. 256 /// \p PCAddr points to the PC value after the call instruction. 257 /// \p CallAddr points to the PC value at the call instruction (or is null). 258 /// \p CallReg is a register location for an indirect call. For direct calls 259 /// the \p CallReg is set to 0. 260 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, DIE *CalleeDIE, bool IsTail, 261 const MCSymbol *PCAddr, 262 const MCSymbol *CallAddr, unsigned CallReg); 263 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params 264 /// were collected by the \ref collectCallSiteParameters. 265 /// Note: The order of parameters does not matter, since debuggers recognize 266 /// call site parameters by the DW_AT_location attribute. 267 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE, 268 SmallVector<DbgCallSiteParam, 4> &Params); 269 270 /// Construct import_module DIE. 271 DIE *constructImportedEntityDIE(const DIImportedEntity *Module); 272 273 void finishSubprogramDefinition(const DISubprogram *SP); 274 void finishEntityDefinition(const DbgEntity *Entity); 275 276 /// Find abstract variable associated with Var. 277 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 278 DbgEntity *getExistingAbstractEntity(const DINode *Node); 279 void createAbstractEntity(const DINode *Node, LexicalScope *Scope); 280 281 /// Set the skeleton unit associated with this unit. setSkeleton(DwarfCompileUnit & Skel)282 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; } 283 getHeaderSize()284 unsigned getHeaderSize() const override { 285 // DWARF v5 added the DWO ID to the header for split/skeleton units. 286 unsigned DWOIdSize = 287 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t) 288 : 0; 289 return DwarfUnit::getHeaderSize() + DWOIdSize; 290 } getLength()291 unsigned getLength() { 292 return Asm->getUnitLengthFieldByteSize() + // Length field 293 getHeaderSize() + getUnitDie().getSize(); 294 } 295 296 void emitHeader(bool UseOffsets) override; 297 298 /// Add the DW_AT_addr_base attribute to the unit DIE. 299 void addAddrTableBase(); 300 getLabelBegin()301 MCSymbol *getLabelBegin() const { 302 assert(LabelBegin && "LabelBegin is not initialized"); 303 return LabelBegin; 304 } 305 getMacroLabelBegin()306 MCSymbol *getMacroLabelBegin() const { 307 return MacroLabelBegin; 308 } 309 310 /// Add a new global name to the compile unit. 311 void addGlobalName(StringRef Name, const DIE &Die, 312 const DIScope *Context) override; 313 314 /// Add a new global name present in a type unit to this compile unit. 315 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context); 316 317 /// Add a new global type to the compile unit. 318 void addGlobalType(const DIType *Ty, const DIE &Die, 319 const DIScope *Context) override; 320 321 /// Add a new global type present in a type unit to this compile unit. 322 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context); 323 getGlobalNames()324 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; } getGlobalTypes()325 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; } 326 327 /// Add DW_AT_location attribute for a DbgVariable based on provided 328 /// MachineLocation. 329 void addVariableAddress(const DbgVariable &DV, DIE &Die, 330 MachineLocation Location); 331 /// Add an address attribute to a die based on the location provided. 332 void addAddress(DIE &Die, dwarf::Attribute Attribute, 333 const MachineLocation &Location); 334 335 /// Start with the address based on the location provided, and generate the 336 /// DWARF information necessary to find the actual variable (navigating the 337 /// extra location information encoded in the type) based on the starting 338 /// location. Add the DWARF information to the die. 339 void addComplexAddress(const DbgVariable &DV, DIE &Die, 340 dwarf::Attribute Attribute, 341 const MachineLocation &Location); 342 343 /// Add a Dwarf loclistptr attribute data and value. 344 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index); 345 void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie); 346 347 /// Add a Dwarf expression attribute data and value. 348 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr); 349 350 void applySubprogramAttributesToDefinition(const DISubprogram *SP, 351 DIE &SPDie); 352 353 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie); 354 355 /// getRanges - Get the list of ranges for this unit. getRanges()356 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; } takeRanges()357 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); } 358 setBaseAddress(const MCSymbol * Base)359 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; } getBaseAddress()360 const MCSymbol *getBaseAddress() const { return BaseAddress; } 361 getDWOId()362 uint64_t getDWOId() const { return DWOId; } setDWOId(uint64_t DwoId)363 void setDWOId(uint64_t DwoId) { DWOId = DwoId; } 364 365 bool hasDwarfPubSections() const; 366 367 void addBaseTypeRef(DIEValueList &Die, int64_t Idx); 368 }; 369 370 } // end namespace llvm 371 372 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 373