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 using ImportedEntityList = SmallVector<const MDNode *, 8>; 65 using ImportedEntityMap = DenseMap<const MDNode *, ImportedEntityList>; 66 67 ImportedEntityMap ImportedEntities; 68 69 /// GlobalNames - A map of globally visible named entities for this unit. 70 StringMap<const DIE *> GlobalNames; 71 72 /// GlobalTypes - A map of globally visible types for this unit. 73 StringMap<const DIE *> GlobalTypes; 74 75 // List of ranges for a given compile unit. 76 SmallVector<RangeSpan, 2> CURanges; 77 78 // The base address of this unit, if any. Used for relative references in 79 // ranges/locs. 80 const MCSymbol *BaseAddress = nullptr; 81 82 DenseMap<const MDNode *, DIE *> AbstractSPDies; 83 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities; 84 85 /// DWO ID for correlating skeleton and split units. 86 uint64_t DWOId = 0; 87 88 const DIFile *LastFile = nullptr; 89 unsigned LastFileID; 90 91 /// Construct a DIE for the given DbgVariable without initializing the 92 /// DbgVariable's DIE reference. 93 DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract); 94 95 bool isDwoUnit() const override; 96 97 DenseMap<const MDNode *, DIE *> &getAbstractSPDies() { 98 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 99 return AbstractSPDies; 100 return DU->getAbstractSPDies(); 101 } 102 103 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() { 104 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 105 return AbstractEntities; 106 return DU->getAbstractEntities(); 107 } 108 109 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 110 111 public: 112 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A, 113 DwarfDebug *DW, DwarfFile *DWU, 114 UnitKind Kind = UnitKind::Full); 115 116 bool hasRangeLists() const { return HasRangeLists; } 117 unsigned getUniqueID() const { return UniqueID; } 118 119 DwarfCompileUnit *getSkeleton() const { 120 return Skeleton; 121 } 122 123 bool includeMinimalInlineScopes() const; 124 125 void initStmtList(); 126 127 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE. 128 void applyStmtList(DIE &D); 129 130 /// Get line table start symbol for this unit. 131 MCSymbol *getLineTableStartSym() const { return LineTableStartSym; } 132 133 /// A pair of GlobalVariable and DIExpression. 134 struct GlobalExpr { 135 const GlobalVariable *Var; 136 const DIExpression *Expr; 137 }; 138 139 struct BaseTypeRef { 140 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) : 141 BitSize(BitSize), Encoding(Encoding) {} 142 unsigned BitSize; 143 dwarf::TypeKind Encoding; 144 DIE *Die = nullptr; 145 }; 146 147 std::vector<BaseTypeRef> ExprRefedBaseTypes; 148 149 /// Get or create global variable DIE. 150 DIE * 151 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV, 152 ArrayRef<GlobalExpr> GlobalExprs); 153 154 DIE *getOrCreateCommonBlock(const DICommonBlock *CB, 155 ArrayRef<GlobalExpr> GlobalExprs); 156 157 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV, 158 ArrayRef<GlobalExpr> GlobalExprs); 159 160 /// addLabelAddress - Add a dwarf label attribute data and value using 161 /// either DW_FORM_addr or DW_FORM_GNU_addr_index. 162 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute, 163 const MCSymbol *Label); 164 165 /// addLocalLabelAddress - Add a dwarf label attribute data and value using 166 /// DW_FORM_addr only. 167 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute, 168 const MCSymbol *Label); 169 170 DwarfCompileUnit &getCU() override { return *this; } 171 172 unsigned getOrCreateSourceID(const DIFile *File) override; 173 174 void addImportedEntity(const DIImportedEntity* IE) { 175 DIScope *Scope = IE->getScope(); 176 assert(Scope && "Invalid Scope encoding!"); 177 if (!isa<DILocalScope>(Scope)) 178 // No need to add imported enities that are not local declaration. 179 return; 180 181 auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope(); 182 ImportedEntities[LocalScope].push_back(IE); 183 } 184 185 /// addRange - Add an address range to the list of ranges for this unit. 186 void addRange(RangeSpan Range); 187 188 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End); 189 190 /// Find DIE for the given subprogram and attach appropriate 191 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global 192 /// variables in this scope then create and insert DIEs for these 193 /// variables. 194 DIE &updateSubprogramScopeDIE(const DISubprogram *SP); 195 DIE &updateSubprogramScopeDIEImpl(const DISubprogram *SP, DIE *SPDie); 196 197 void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE); 198 199 /// A helper function to construct a RangeSpanList for a given 200 /// lexical scope. 201 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range); 202 203 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges); 204 205 void attachRangesOrLowHighPC(DIE &D, 206 const SmallVectorImpl<InsnRange> &Ranges); 207 208 /// This scope represents an inlined body of a function. Construct a 209 /// DIE to represent this concrete inlined copy of the function. 210 DIE *constructInlinedScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE); 211 212 /// Construct new DW_TAG_lexical_block for this scope and 213 /// attach DW_AT_low_pc/DW_AT_high_pc labels. 214 DIE *constructLexicalScopeDIE(LexicalScope *Scope); 215 216 /// constructVariableDIE - Construct a DIE for the given DbgVariable. 217 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false); 218 219 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope, 220 DIE *&ObjectPointer); 221 222 /// Construct a DIE for the given DbgLabel. 223 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope); 224 225 void createBaseTypeDIEs(); 226 227 /// Construct a DIE for this subprogram scope. 228 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, 229 LexicalScope *Scope); 230 231 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE); 232 233 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope); 234 235 /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location 236 /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info. 237 bool useGNUAnalogForDwarf5Feature() const; 238 239 /// This takes a DWARF 5 tag and returns it or a GNU analog. 240 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const; 241 242 /// This takes a DWARF 5 attribute and returns it or a GNU analog. 243 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const; 244 245 /// This takes a DWARF 5 location atom and either returns it or a GNU analog. 246 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const; 247 248 /// Construct a call site entry DIE describing a call within \p Scope to a 249 /// callee described by \p CalleeSP. 250 /// \p IsTail specifies whether the call is a tail call. 251 /// \p PCAddr points to the PC value after the call instruction. 252 /// \p CallAddr points to the PC value at the call instruction (or is null). 253 /// \p CallReg is a register location for an indirect call. For direct calls 254 /// the \p CallReg is set to 0. 255 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP, 256 bool IsTail, const MCSymbol *PCAddr, 257 const MCSymbol *CallAddr, unsigned CallReg); 258 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params 259 /// were collected by the \ref collectCallSiteParameters. 260 /// Note: The order of parameters does not matter, since debuggers recognize 261 /// call site parameters by the DW_AT_location attribute. 262 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE, 263 SmallVector<DbgCallSiteParam, 4> &Params); 264 265 /// Construct import_module DIE. 266 DIE *constructImportedEntityDIE(const DIImportedEntity *Module); 267 268 void finishSubprogramDefinition(const DISubprogram *SP); 269 void finishEntityDefinition(const DbgEntity *Entity); 270 271 /// Find abstract variable associated with Var. 272 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 273 DbgEntity *getExistingAbstractEntity(const DINode *Node); 274 void createAbstractEntity(const DINode *Node, LexicalScope *Scope); 275 276 /// Set the skeleton unit associated with this unit. 277 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; } 278 279 unsigned getHeaderSize() const override { 280 // DWARF v5 added the DWO ID to the header for split/skeleton units. 281 unsigned DWOIdSize = 282 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t) 283 : 0; 284 return DwarfUnit::getHeaderSize() + DWOIdSize; 285 } 286 unsigned getLength() { 287 return Asm->getUnitLengthFieldByteSize() + // Length field 288 getHeaderSize() + getUnitDie().getSize(); 289 } 290 291 void emitHeader(bool UseOffsets) override; 292 293 /// Add the DW_AT_addr_base attribute to the unit DIE. 294 void addAddrTableBase(); 295 296 MCSymbol *getLabelBegin() const { 297 assert(LabelBegin && "LabelBegin is not initialized"); 298 return LabelBegin; 299 } 300 301 MCSymbol *getMacroLabelBegin() const { 302 return MacroLabelBegin; 303 } 304 305 /// Add a new global name to the compile unit. 306 void addGlobalName(StringRef Name, const DIE &Die, 307 const DIScope *Context) override; 308 309 /// Add a new global name present in a type unit to this compile unit. 310 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context); 311 312 /// Add a new global type to the compile unit. 313 void addGlobalType(const DIType *Ty, const DIE &Die, 314 const DIScope *Context) override; 315 316 /// Add a new global type present in a type unit to this compile unit. 317 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context); 318 319 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; } 320 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; } 321 322 /// Add DW_AT_location attribute for a DbgVariable based on provided 323 /// MachineLocation. 324 void addVariableAddress(const DbgVariable &DV, DIE &Die, 325 MachineLocation Location); 326 /// Add an address attribute to a die based on the location provided. 327 void addAddress(DIE &Die, dwarf::Attribute Attribute, 328 const MachineLocation &Location); 329 330 /// Start with the address based on the location provided, and generate the 331 /// DWARF information necessary to find the actual variable (navigating the 332 /// extra location information encoded in the type) based on the starting 333 /// location. Add the DWARF information to the die. 334 void addComplexAddress(const DbgVariable &DV, DIE &Die, 335 dwarf::Attribute Attribute, 336 const MachineLocation &Location); 337 338 /// Add a Dwarf loclistptr attribute data and value. 339 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index); 340 void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie); 341 342 /// Add a Dwarf expression attribute data and value. 343 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr); 344 345 void applySubprogramAttributesToDefinition(const DISubprogram *SP, 346 DIE &SPDie); 347 348 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie); 349 350 /// getRanges - Get the list of ranges for this unit. 351 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; } 352 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); } 353 354 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; } 355 const MCSymbol *getBaseAddress() const { return BaseAddress; } 356 357 uint64_t getDWOId() const { return DWOId; } 358 void setDWOId(uint64_t DwoId) { DWOId = DwoId; } 359 360 bool hasDwarfPubSections() const; 361 362 void addBaseTypeRef(DIEValueList &Die, int64_t Idx); 363 }; 364 365 } // end namespace llvm 366 367 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 368