1 //===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- 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 Microsoft CodeView debug info. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 14 #define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 15 16 #include "llvm/ADT/ArrayRef.h" 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/ADT/DenseSet.h" 19 #include "llvm/ADT/MapVector.h" 20 #include "llvm/ADT/PointerUnion.h" 21 #include "llvm/ADT/SetVector.h" 22 #include "llvm/ADT/SmallVector.h" 23 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h" 24 #include "llvm/CodeGen/DebugHandlerBase.h" 25 #include "llvm/DebugInfo/CodeView/CodeView.h" 26 #include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h" 27 #include "llvm/DebugInfo/CodeView/TypeIndex.h" 28 #include "llvm/IR/DebugLoc.h" 29 #include "llvm/Support/Allocator.h" 30 #include "llvm/Support/Compiler.h" 31 #include <cstdint> 32 #include <map> 33 #include <string> 34 #include <tuple> 35 #include <unordered_map> 36 #include <utility> 37 #include <vector> 38 39 namespace llvm { 40 41 struct ClassInfo; 42 class StringRef; 43 class AsmPrinter; 44 class Function; 45 class GlobalVariable; 46 class MCSectionCOFF; 47 class MCStreamer; 48 class MCSymbol; 49 class MachineFunction; 50 51 /// Collects and handles line tables information in a CodeView format. 52 class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase { 53 MCStreamer &OS; 54 BumpPtrAllocator Allocator; 55 codeview::GlobalTypeTableBuilder TypeTable; 56 57 /// Whether to emit type record hashes into .debug$H. 58 bool EmitDebugGlobalHashes = false; 59 60 /// The codeview CPU type used by the translation unit. 61 codeview::CPUType TheCPU; 62 63 /// Represents the most general definition range. 64 struct LocalVarDefRange { 65 /// Indicates that variable data is stored in memory relative to the 66 /// specified register. 67 int InMemory : 1; 68 69 /// Offset of variable data in memory. 70 int DataOffset : 31; 71 72 /// Non-zero if this is a piece of an aggregate. 73 uint16_t IsSubfield : 1; 74 75 /// Offset into aggregate. 76 uint16_t StructOffset : 15; 77 78 /// Register containing the data or the register base of the memory 79 /// location containing the data. 80 uint16_t CVRegister; 81 82 /// Compares all location fields. This includes all fields except the label 83 /// ranges. 84 bool isDifferentLocation(LocalVarDefRange &O) { 85 return InMemory != O.InMemory || DataOffset != O.DataOffset || 86 IsSubfield != O.IsSubfield || StructOffset != O.StructOffset || 87 CVRegister != O.CVRegister; 88 } 89 90 SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1> Ranges; 91 }; 92 93 static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset); 94 95 /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific. 96 struct LocalVariable { 97 const DILocalVariable *DIVar = nullptr; 98 SmallVector<LocalVarDefRange, 1> DefRanges; 99 bool UseReferenceType = false; 100 }; 101 102 struct CVGlobalVariable { 103 const DIGlobalVariable *DIGV; 104 PointerUnion<const GlobalVariable *, const DIExpression *> GVInfo; 105 }; 106 107 struct InlineSite { 108 SmallVector<LocalVariable, 1> InlinedLocals; 109 SmallVector<const DILocation *, 1> ChildSites; 110 const DISubprogram *Inlinee = nullptr; 111 112 /// The ID of the inline site or function used with .cv_loc. Not a type 113 /// index. 114 unsigned SiteFuncId = 0; 115 }; 116 117 // Combines information from DILexicalBlock and LexicalScope. 118 struct LexicalBlock { 119 SmallVector<LocalVariable, 1> Locals; 120 SmallVector<CVGlobalVariable, 1> Globals; 121 SmallVector<LexicalBlock *, 1> Children; 122 const MCSymbol *Begin; 123 const MCSymbol *End; 124 StringRef Name; 125 }; 126 127 // For each function, store a vector of labels to its instructions, as well as 128 // to the end of the function. 129 struct FunctionInfo { 130 FunctionInfo() = default; 131 132 // Uncopyable. 133 FunctionInfo(const FunctionInfo &FI) = delete; 134 135 /// Map from inlined call site to inlined instructions and child inlined 136 /// call sites. Listed in program order. 137 std::unordered_map<const DILocation *, InlineSite> InlineSites; 138 139 /// Ordered list of top-level inlined call sites. 140 SmallVector<const DILocation *, 1> ChildSites; 141 142 SmallVector<LocalVariable, 1> Locals; 143 SmallVector<CVGlobalVariable, 1> Globals; 144 145 std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks; 146 147 // Lexical blocks containing local variables. 148 SmallVector<LexicalBlock *, 1> ChildBlocks; 149 150 std::vector<std::pair<MCSymbol *, MDNode *>> Annotations; 151 std::vector<std::tuple<MCSymbol *, MCSymbol *, const DIType *>> 152 HeapAllocSites; 153 154 const MCSymbol *Begin = nullptr; 155 const MCSymbol *End = nullptr; 156 unsigned FuncId = 0; 157 unsigned LastFileId = 0; 158 159 /// Number of bytes allocated in the prologue for all local stack objects. 160 unsigned FrameSize = 0; 161 162 /// Number of bytes of parameters on the stack. 163 unsigned ParamSize = 0; 164 165 /// Number of bytes pushed to save CSRs. 166 unsigned CSRSize = 0; 167 168 /// Adjustment to apply on x86 when using the VFRAME frame pointer. 169 int OffsetAdjustment = 0; 170 171 /// Two-bit value indicating which register is the designated frame pointer 172 /// register for local variables. Included in S_FRAMEPROC. 173 codeview::EncodedFramePtrReg EncodedLocalFramePtrReg = 174 codeview::EncodedFramePtrReg::None; 175 176 /// Two-bit value indicating which register is the designated frame pointer 177 /// register for stack parameters. Included in S_FRAMEPROC. 178 codeview::EncodedFramePtrReg EncodedParamFramePtrReg = 179 codeview::EncodedFramePtrReg::None; 180 181 codeview::FrameProcedureOptions FrameProcOpts; 182 183 bool HasStackRealignment = false; 184 185 bool HaveLineInfo = false; 186 }; 187 FunctionInfo *CurFn = nullptr; 188 189 // Map used to seperate variables according to the lexical scope they belong 190 // in. This is populated by recordLocalVariable() before 191 // collectLexicalBlocks() separates the variables between the FunctionInfo 192 // and LexicalBlocks. 193 DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables; 194 195 // Map to separate global variables according to the lexical scope they 196 // belong in. A null local scope represents the global scope. 197 typedef SmallVector<CVGlobalVariable, 1> GlobalVariableList; 198 DenseMap<const DIScope*, std::unique_ptr<GlobalVariableList> > ScopeGlobals; 199 200 // Array of global variables which need to be emitted into a COMDAT section. 201 SmallVector<CVGlobalVariable, 1> ComdatVariables; 202 203 // Array of non-COMDAT global variables. 204 SmallVector<CVGlobalVariable, 1> GlobalVariables; 205 206 /// The set of comdat .debug$S sections that we've seen so far. Each section 207 /// must start with a magic version number that must only be emitted once. 208 /// This set tracks which sections we've already opened. 209 DenseSet<MCSectionCOFF *> ComdatDebugSections; 210 211 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol 212 /// of an emitted global value, is in a comdat COFF section, this will switch 213 /// to a new .debug$S section in that comdat. This method ensures that the 214 /// section starts with the magic version number on first use. If GVSym is 215 /// null, uses the main .debug$S section. 216 void switchToDebugSectionForSymbol(const MCSymbol *GVSym); 217 218 /// The next available function index for use with our .cv_* directives. Not 219 /// to be confused with type indices for LF_FUNC_ID records. 220 unsigned NextFuncId = 0; 221 222 InlineSite &getInlineSite(const DILocation *InlinedAt, 223 const DISubprogram *Inlinee); 224 225 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP); 226 227 void calculateRanges(LocalVariable &Var, 228 const DbgValueHistoryMap::Entries &Entries); 229 230 static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children, 231 const FunctionInfo &FI, 232 const InlineSite &Site); 233 234 /// Remember some debug info about each function. Keep it in a stable order to 235 /// emit at the end of the TU. 236 MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo; 237 238 /// Map from full file path to .cv_file id. Full paths are built from DIFiles 239 /// and are stored in FileToFilepathMap; 240 DenseMap<StringRef, unsigned> FileIdMap; 241 242 /// All inlined subprograms in the order they should be emitted. 243 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms; 244 245 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can 246 /// be nullptr, to CodeView type indices. Primarily indexed by 247 /// {DIType*, DIType*} and {DISubprogram*, DIType*}. 248 /// 249 /// The second entry in the key is needed for methods as DISubroutineType 250 /// representing static method type are shared with non-method function type. 251 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex> 252 TypeIndices; 253 254 /// Map from DICompositeType* to complete type index. Non-record types are 255 /// always looked up in the normal TypeIndices map. 256 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices; 257 258 /// Complete record types to emit after all active type lowerings are 259 /// finished. 260 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes; 261 262 /// Number of type lowering frames active on the stack. 263 unsigned TypeEmissionLevel = 0; 264 265 codeview::TypeIndex VBPType; 266 267 const DISubprogram *CurrentSubprogram = nullptr; 268 269 // The UDTs we have seen while processing types; each entry is a pair of type 270 // index and type name. 271 std::vector<std::pair<std::string, const DIType *>> LocalUDTs; 272 std::vector<std::pair<std::string, const DIType *>> GlobalUDTs; 273 274 using FileToFilepathMapTy = std::map<const DIFile *, std::string>; 275 FileToFilepathMapTy FileToFilepathMap; 276 277 StringRef getFullFilepath(const DIFile *File); 278 279 unsigned maybeRecordFile(const DIFile *F); 280 281 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF); 282 283 void clear(); 284 285 void setCurrentSubprogram(const DISubprogram *SP) { 286 CurrentSubprogram = SP; 287 LocalUDTs.clear(); 288 } 289 290 /// Emit the magic version number at the start of a CodeView type or symbol 291 /// section. Appears at the front of every .debug$S or .debug$T or .debug$P 292 /// section. 293 void emitCodeViewMagicVersion(); 294 295 void emitTypeInformation(); 296 297 void emitTypeGlobalHashes(); 298 299 void emitCompilerInformation(); 300 301 void emitBuildInfo(); 302 303 void emitInlineeLinesSubsection(); 304 305 void emitDebugInfoForThunk(const Function *GV, 306 FunctionInfo &FI, 307 const MCSymbol *Fn); 308 309 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI); 310 311 void emitDebugInfoForRetainedTypes(); 312 313 void 314 emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs); 315 316 void emitDebugInfoForGlobals(); 317 void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals); 318 void emitDebugInfoForGlobal(const CVGlobalVariable &CVGV); 319 320 /// Opens a subsection of the given kind in a .debug$S codeview section. 321 /// Returns an end label for use with endCVSubsection when the subsection is 322 /// finished. 323 MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind); 324 void endCVSubsection(MCSymbol *EndLabel); 325 326 /// Opens a symbol record of the given kind. Returns an end label for use with 327 /// endSymbolRecord. 328 MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind); 329 void endSymbolRecord(MCSymbol *SymEnd); 330 331 /// Emits an S_END, S_INLINESITE_END, or S_PROC_ID_END record. These records 332 /// are empty, so we emit them with a simpler assembly sequence that doesn't 333 /// involve labels. 334 void emitEndSymbolRecord(codeview::SymbolKind EndKind); 335 336 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt, 337 const InlineSite &Site); 338 339 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 340 341 void collectGlobalVariableInfo(); 342 void collectVariableInfo(const DISubprogram *SP); 343 344 void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed); 345 346 // Construct the lexical block tree for a routine, pruning emptpy lexical 347 // scopes, and populate it with local variables. 348 void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes, 349 SmallVectorImpl<LexicalBlock *> &Blocks, 350 SmallVectorImpl<LocalVariable> &Locals, 351 SmallVectorImpl<CVGlobalVariable> &Globals); 352 void collectLexicalBlockInfo(LexicalScope &Scope, 353 SmallVectorImpl<LexicalBlock *> &ParentBlocks, 354 SmallVectorImpl<LocalVariable> &ParentLocals, 355 SmallVectorImpl<CVGlobalVariable> &ParentGlobals); 356 357 /// Records information about a local variable in the appropriate scope. In 358 /// particular, locals from inlined code live inside the inlining site. 359 void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS); 360 361 /// Emits local variables in the appropriate order. 362 void emitLocalVariableList(const FunctionInfo &FI, 363 ArrayRef<LocalVariable> Locals); 364 365 /// Emits an S_LOCAL record and its associated defined ranges. 366 void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var); 367 368 /// Emits a sequence of lexical block scopes and their children. 369 void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks, 370 const FunctionInfo& FI); 371 372 /// Emit a lexical block scope and its children. 373 void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI); 374 375 /// Translates the DIType to codeview if necessary and returns a type index 376 /// for it. 377 codeview::TypeIndex getTypeIndex(const DIType *Ty, 378 const DIType *ClassTy = nullptr); 379 380 codeview::TypeIndex 381 getTypeIndexForThisPtr(const DIDerivedType *PtrTy, 382 const DISubroutineType *SubroutineTy); 383 384 codeview::TypeIndex getTypeIndexForReferenceTo(const DIType *Ty); 385 386 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP, 387 const DICompositeType *Class); 388 389 codeview::TypeIndex getScopeIndex(const DIScope *Scope); 390 391 codeview::TypeIndex getVBPTypeIndex(); 392 393 void addToUDTs(const DIType *Ty); 394 395 void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI); 396 397 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy); 398 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty); 399 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty); 400 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty); 401 codeview::TypeIndex lowerTypePointer( 402 const DIDerivedType *Ty, 403 codeview::PointerOptions PO = codeview::PointerOptions::None); 404 codeview::TypeIndex lowerTypeMemberPointer( 405 const DIDerivedType *Ty, 406 codeview::PointerOptions PO = codeview::PointerOptions::None); 407 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty); 408 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty); 409 codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty); 410 codeview::TypeIndex lowerTypeMemberFunction( 411 const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment, 412 bool IsStaticMethod, 413 codeview::FunctionOptions FO = codeview::FunctionOptions::None); 414 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty); 415 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty); 416 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty); 417 418 /// Symbol records should point to complete types, but type records should 419 /// always point to incomplete types to avoid cycles in the type graph. Only 420 /// use this entry point when generating symbol records. The complete and 421 /// incomplete type indices only differ for record types. All other types use 422 /// the same index. 423 codeview::TypeIndex getCompleteTypeIndex(const DIType *Ty); 424 425 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty); 426 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty); 427 428 struct TypeLoweringScope; 429 430 void emitDeferredCompleteTypes(); 431 432 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy); 433 ClassInfo collectClassInfo(const DICompositeType *Ty); 434 435 /// Common record member lowering functionality for record types, which are 436 /// structs, classes, and unions. Returns the field list index and the member 437 /// count. 438 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool> 439 lowerRecordFieldList(const DICompositeType *Ty); 440 441 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates. 442 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node, 443 codeview::TypeIndex TI, 444 const DIType *ClassTy = nullptr); 445 446 unsigned getPointerSizeInBytes(); 447 448 protected: 449 /// Gather pre-function debug information. 450 void beginFunctionImpl(const MachineFunction *MF) override; 451 452 /// Gather post-function debug information. 453 void endFunctionImpl(const MachineFunction *) override; 454 455 public: 456 CodeViewDebug(AsmPrinter *AP); 457 458 void setSymbolSize(const MCSymbol *, uint64_t) override {} 459 460 /// Emit the COFF section that holds the line table information. 461 void endModule() override; 462 463 /// Process beginning of an instruction. 464 void beginInstruction(const MachineInstr *MI) override; 465 }; 466 467 } // end namespace llvm 468 469 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 470