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/DIE.h" 26 #include "llvm/CodeGen/LexicalScopes.h" 27 #include "llvm/IR/DebugInfoMetadata.h" 28 #include "llvm/Support/Casting.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <memory> 33 34 namespace llvm { 35 36 class AsmPrinter; 37 class DwarfFile; 38 class GlobalVariable; 39 class MCExpr; 40 class MCSymbol; 41 class MDNode; 42 43 class DwarfCompileUnit final : public DwarfUnit { 44 /// A numeric ID unique among all CUs in the module 45 unsigned UniqueID; 46 bool HasRangeLists = false; 47 48 /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding 49 /// the need to search for it in applyStmtList. 50 DIE::value_iterator StmtListValue; 51 52 /// Skeleton unit associated with this unit. 53 DwarfCompileUnit *Skeleton = nullptr; 54 55 /// The start of the unit within its section. 56 MCSymbol *LabelBegin; 57 58 /// The start of the unit macro info within macro section. 59 MCSymbol *MacroLabelBegin; 60 61 using ImportedEntityList = SmallVector<const MDNode *, 8>; 62 using ImportedEntityMap = DenseMap<const MDNode *, ImportedEntityList>; 63 64 ImportedEntityMap ImportedEntities; 65 66 /// GlobalNames - A map of globally visible named entities for this unit. 67 StringMap<const DIE *> GlobalNames; 68 69 /// GlobalTypes - A map of globally visible types for this unit. 70 StringMap<const DIE *> GlobalTypes; 71 72 // List of ranges for a given compile unit. 73 SmallVector<RangeSpan, 2> CURanges; 74 75 // The base address of this unit, if any. Used for relative references in 76 // ranges/locs. 77 const MCSymbol *BaseAddress = nullptr; 78 79 DenseMap<const MDNode *, DIE *> AbstractSPDies; 80 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities; 81 82 /// DWO ID for correlating skeleton and split units. 83 uint64_t DWOId = 0; 84 85 /// Construct a DIE for the given DbgVariable without initializing the 86 /// DbgVariable's DIE reference. 87 DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract); 88 89 bool isDwoUnit() const override; 90 91 DenseMap<const MDNode *, DIE *> &getAbstractSPDies() { 92 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 93 return AbstractSPDies; 94 return DU->getAbstractSPDies(); 95 } 96 97 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() { 98 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 99 return AbstractEntities; 100 return DU->getAbstractEntities(); 101 } 102 103 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 104 105 public: 106 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A, 107 DwarfDebug *DW, DwarfFile *DWU); 108 109 bool hasRangeLists() const { return HasRangeLists; } 110 unsigned getUniqueID() const { return UniqueID; } 111 112 DwarfCompileUnit *getSkeleton() const { 113 return Skeleton; 114 } 115 116 bool includeMinimalInlineScopes() const; 117 118 void initStmtList(); 119 120 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE. 121 void applyStmtList(DIE &D); 122 123 /// A pair of GlobalVariable and DIExpression. 124 struct GlobalExpr { 125 const GlobalVariable *Var; 126 const DIExpression *Expr; 127 }; 128 129 struct BaseTypeRef { 130 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) : 131 BitSize(BitSize), Encoding(Encoding) {} 132 unsigned BitSize; 133 dwarf::TypeKind Encoding; 134 DIE *Die = nullptr; 135 }; 136 137 std::vector<BaseTypeRef> ExprRefedBaseTypes; 138 139 /// Get or create global variable DIE. 140 DIE * 141 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV, 142 ArrayRef<GlobalExpr> GlobalExprs); 143 144 DIE *getOrCreateCommonBlock(const DICommonBlock *CB, 145 ArrayRef<GlobalExpr> GlobalExprs); 146 147 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV, 148 ArrayRef<GlobalExpr> GlobalExprs); 149 150 /// addLabelAddress - Add a dwarf label attribute data and value using 151 /// either DW_FORM_addr or DW_FORM_GNU_addr_index. 152 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute, 153 const MCSymbol *Label); 154 155 /// addLocalLabelAddress - Add a dwarf label attribute data and value using 156 /// DW_FORM_addr only. 157 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute, 158 const MCSymbol *Label); 159 160 DwarfCompileUnit &getCU() override { return *this; } 161 162 unsigned getOrCreateSourceID(const DIFile *File) override; 163 164 void addImportedEntity(const DIImportedEntity* IE) { 165 DIScope *Scope = IE->getScope(); 166 assert(Scope && "Invalid Scope encoding!"); 167 if (!isa<DILocalScope>(Scope)) 168 // No need to add imported enities that are not local declaration. 169 return; 170 171 auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope(); 172 ImportedEntities[LocalScope].push_back(IE); 173 } 174 175 /// addRange - Add an address range to the list of ranges for this unit. 176 void addRange(RangeSpan Range); 177 178 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End); 179 180 /// Find DIE for the given subprogram and attach appropriate 181 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global 182 /// variables in this scope then create and insert DIEs for these 183 /// variables. 184 DIE &updateSubprogramScopeDIE(const DISubprogram *SP); 185 186 void constructScopeDIE(LexicalScope *Scope, 187 SmallVectorImpl<DIE *> &FinalChildren); 188 189 /// A helper function to construct a RangeSpanList for a given 190 /// lexical scope. 191 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range); 192 193 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges); 194 195 void attachRangesOrLowHighPC(DIE &D, 196 const SmallVectorImpl<InsnRange> &Ranges); 197 198 /// This scope represents inlined body of a function. Construct 199 /// DIE to represent this concrete inlined copy of the function. 200 DIE *constructInlinedScopeDIE(LexicalScope *Scope); 201 202 /// Construct new DW_TAG_lexical_block for this scope and 203 /// attach DW_AT_low_pc/DW_AT_high_pc labels. 204 DIE *constructLexicalScopeDIE(LexicalScope *Scope); 205 206 /// constructVariableDIE - Construct a DIE for the given DbgVariable. 207 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false); 208 209 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope, 210 DIE *&ObjectPointer); 211 212 /// Construct a DIE for the given DbgLabel. 213 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope); 214 215 /// A helper function to create children of a Scope DIE. 216 DIE *createScopeChildrenDIE(LexicalScope *Scope, 217 SmallVectorImpl<DIE *> &Children, 218 bool *HasNonScopeChildren = nullptr); 219 220 void createBaseTypeDIEs(); 221 222 /// Construct a DIE for this subprogram scope. 223 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, 224 LexicalScope *Scope); 225 226 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE); 227 228 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope); 229 230 /// This takes a DWARF 5 tag and returns it or a GNU analog. 231 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const; 232 233 /// This takes a DWARF 5 attribute and returns it or a GNU analog. 234 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const; 235 236 /// This takes a DWARF 5 location atom and either returns it or a GNU analog. 237 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const; 238 239 /// Construct a call site entry DIE describing a call within \p Scope to a 240 /// callee described by \p CalleeSP. 241 /// \p IsTail specifies whether the call is a tail call. 242 /// \p PCAddr (used for GDB + DWARF 4 tuning) points to the PC value after 243 /// the call instruction. 244 /// \p PCOffset (used for cases other than GDB + DWARF 4 tuning) must be 245 /// non-zero for non-tail calls (in the case of non-gdb tuning, since for 246 /// GDB + DWARF 5 tuning we still generate PC info for tail calls) or be the 247 /// function-local offset to PC value after the call instruction. 248 /// \p CallReg is a register location for an indirect call. For direct calls 249 /// the \p CallReg is set to 0. 250 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP, 251 bool IsTail, const MCSymbol *PCAddr, 252 const MCExpr *PCOffset, unsigned CallReg); 253 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params 254 /// were collected by the \ref collectCallSiteParameters. 255 /// Note: The order of parameters does not matter, since debuggers recognize 256 /// call site parameters by the DW_AT_location attribute. 257 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE, 258 SmallVector<DbgCallSiteParam, 4> &Params); 259 260 /// Construct import_module DIE. 261 DIE *constructImportedEntityDIE(const DIImportedEntity *Module); 262 263 void finishSubprogramDefinition(const DISubprogram *SP); 264 void finishEntityDefinition(const DbgEntity *Entity); 265 266 /// Find abstract variable associated with Var. 267 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 268 DbgEntity *getExistingAbstractEntity(const DINode *Node); 269 void createAbstractEntity(const DINode *Node, LexicalScope *Scope); 270 271 /// Set the skeleton unit associated with this unit. 272 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; } 273 274 unsigned getHeaderSize() const override { 275 // DWARF v5 added the DWO ID to the header for split/skeleton units. 276 unsigned DWOIdSize = 277 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t) 278 : 0; 279 return DwarfUnit::getHeaderSize() + DWOIdSize; 280 } 281 unsigned getLength() { 282 return sizeof(uint32_t) + // Length field 283 getHeaderSize() + getUnitDie().getSize(); 284 } 285 286 void emitHeader(bool UseOffsets) override; 287 288 /// Add the DW_AT_addr_base attribute to the unit DIE. 289 void addAddrTableBase(); 290 291 MCSymbol *getLabelBegin() const { 292 assert(getSection()); 293 return LabelBegin; 294 } 295 296 MCSymbol *getMacroLabelBegin() const { 297 return MacroLabelBegin; 298 } 299 300 /// Add a new global name to the compile unit. 301 void addGlobalName(StringRef Name, const DIE &Die, 302 const DIScope *Context) override; 303 304 /// Add a new global name present in a type unit to this compile unit. 305 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context); 306 307 /// Add a new global type to the compile unit. 308 void addGlobalType(const DIType *Ty, const DIE &Die, 309 const DIScope *Context) override; 310 311 /// Add a new global type present in a type unit to this compile unit. 312 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context); 313 314 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; } 315 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; } 316 317 /// Add DW_AT_location attribute for a DbgVariable based on provided 318 /// MachineLocation. 319 void addVariableAddress(const DbgVariable &DV, DIE &Die, 320 MachineLocation Location); 321 /// Add an address attribute to a die based on the location provided. 322 void addAddress(DIE &Die, dwarf::Attribute Attribute, 323 const MachineLocation &Location); 324 325 /// Start with the address based on the location provided, and generate the 326 /// DWARF information necessary to find the actual variable (navigating the 327 /// extra location information encoded in the type) based on the starting 328 /// location. Add the DWARF information to the die. 329 void addComplexAddress(const DbgVariable &DV, DIE &Die, 330 dwarf::Attribute Attribute, 331 const MachineLocation &Location); 332 333 /// Add a Dwarf loclistptr attribute data and value. 334 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index); 335 void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie); 336 337 /// Add a Dwarf expression attribute data and value. 338 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr); 339 340 /// Add an attribute containing an address expression to \p Die. 341 void addAddressExpr(DIE &Die, dwarf::Attribute Attribute, const MCExpr *Expr); 342 343 void applySubprogramAttributesToDefinition(const DISubprogram *SP, 344 DIE &SPDie); 345 346 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie); 347 348 /// getRanges - Get the list of ranges for this unit. 349 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; } 350 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); } 351 352 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; } 353 const MCSymbol *getBaseAddress() const { return BaseAddress; } 354 355 uint64_t getDWOId() const { return DWOId; } 356 void setDWOId(uint64_t DwoId) { DWOId = DwoId; } 357 358 bool hasDwarfPubSections() const; 359 360 void addBaseTypeRef(DIEValueList &Die, int64_t Idx); 361 }; 362 363 } // end namespace llvm 364 365 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 366