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 *, DIType *>> HeapAllocSites; 152 153 const MCSymbol *Begin = nullptr; 154 const MCSymbol *End = nullptr; 155 unsigned FuncId = 0; 156 unsigned LastFileId = 0; 157 158 /// Number of bytes allocated in the prologue for all local stack objects. 159 unsigned FrameSize = 0; 160 161 /// Number of bytes of parameters on the stack. 162 unsigned ParamSize = 0; 163 164 /// Number of bytes pushed to save CSRs. 165 unsigned CSRSize = 0; 166 167 /// Adjustment to apply on x86 when using the VFRAME frame pointer. 168 int OffsetAdjustment = 0; 169 170 /// Two-bit value indicating which register is the designated frame pointer 171 /// register for local variables. Included in S_FRAMEPROC. 172 codeview::EncodedFramePtrReg EncodedLocalFramePtrReg = 173 codeview::EncodedFramePtrReg::None; 174 175 /// Two-bit value indicating which register is the designated frame pointer 176 /// register for stack parameters. Included in S_FRAMEPROC. 177 codeview::EncodedFramePtrReg EncodedParamFramePtrReg = 178 codeview::EncodedFramePtrReg::None; 179 180 codeview::FrameProcedureOptions FrameProcOpts; 181 182 bool HasStackRealignment = false; 183 184 bool HaveLineInfo = false; 185 }; 186 FunctionInfo *CurFn = nullptr; 187 188 // Map used to seperate variables according to the lexical scope they belong 189 // in. This is populated by recordLocalVariable() before 190 // collectLexicalBlocks() separates the variables between the FunctionInfo 191 // and LexicalBlocks. 192 DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables; 193 194 // Map to separate global variables according to the lexical scope they 195 // belong in. A null local scope represents the global scope. 196 typedef SmallVector<CVGlobalVariable, 1> GlobalVariableList; 197 DenseMap<const DIScope*, std::unique_ptr<GlobalVariableList> > ScopeGlobals; 198 199 // Array of global variables which need to be emitted into a COMDAT section. 200 SmallVector<CVGlobalVariable, 1> ComdatVariables; 201 202 // Array of non-COMDAT global variables. 203 SmallVector<CVGlobalVariable, 1> GlobalVariables; 204 205 /// The set of comdat .debug$S sections that we've seen so far. Each section 206 /// must start with a magic version number that must only be emitted once. 207 /// This set tracks which sections we've already opened. 208 DenseSet<MCSectionCOFF *> ComdatDebugSections; 209 210 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol 211 /// of an emitted global value, is in a comdat COFF section, this will switch 212 /// to a new .debug$S section in that comdat. This method ensures that the 213 /// section starts with the magic version number on first use. If GVSym is 214 /// null, uses the main .debug$S section. 215 void switchToDebugSectionForSymbol(const MCSymbol *GVSym); 216 217 /// The next available function index for use with our .cv_* directives. Not 218 /// to be confused with type indices for LF_FUNC_ID records. 219 unsigned NextFuncId = 0; 220 221 InlineSite &getInlineSite(const DILocation *InlinedAt, 222 const DISubprogram *Inlinee); 223 224 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP); 225 226 void calculateRanges(LocalVariable &Var, 227 const DbgValueHistoryMap::Entries &Entries); 228 229 static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children, 230 const FunctionInfo &FI, 231 const InlineSite &Site); 232 233 /// Remember some debug info about each function. Keep it in a stable order to 234 /// emit at the end of the TU. 235 MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo; 236 237 /// Map from full file path to .cv_file id. Full paths are built from DIFiles 238 /// and are stored in FileToFilepathMap; 239 DenseMap<StringRef, unsigned> FileIdMap; 240 241 /// All inlined subprograms in the order they should be emitted. 242 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms; 243 244 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can 245 /// be nullptr, to CodeView type indices. Primarily indexed by 246 /// {DIType*, DIType*} and {DISubprogram*, DIType*}. 247 /// 248 /// The second entry in the key is needed for methods as DISubroutineType 249 /// representing static method type are shared with non-method function type. 250 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex> 251 TypeIndices; 252 253 /// Map from DICompositeType* to complete type index. Non-record types are 254 /// always looked up in the normal TypeIndices map. 255 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices; 256 257 /// Complete record types to emit after all active type lowerings are 258 /// finished. 259 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes; 260 261 /// Number of type lowering frames active on the stack. 262 unsigned TypeEmissionLevel = 0; 263 264 codeview::TypeIndex VBPType; 265 266 const DISubprogram *CurrentSubprogram = nullptr; 267 268 // The UDTs we have seen while processing types; each entry is a pair of type 269 // index and type name. 270 std::vector<std::pair<std::string, const DIType *>> LocalUDTs; 271 std::vector<std::pair<std::string, const DIType *>> GlobalUDTs; 272 273 using FileToFilepathMapTy = std::map<const DIFile *, std::string>; 274 FileToFilepathMapTy FileToFilepathMap; 275 276 StringRef getFullFilepath(const DIFile *File); 277 278 unsigned maybeRecordFile(const DIFile *F); 279 280 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF); 281 282 void clear(); 283 284 void setCurrentSubprogram(const DISubprogram *SP) { 285 CurrentSubprogram = SP; 286 LocalUDTs.clear(); 287 } 288 289 /// Emit the magic version number at the start of a CodeView type or symbol 290 /// section. Appears at the front of every .debug$S or .debug$T or .debug$P 291 /// section. 292 void emitCodeViewMagicVersion(); 293 294 void emitTypeInformation(); 295 296 void emitTypeGlobalHashes(); 297 298 void emitCompilerInformation(); 299 300 void emitBuildInfo(); 301 302 void emitInlineeLinesSubsection(); 303 304 void emitDebugInfoForThunk(const Function *GV, 305 FunctionInfo &FI, 306 const MCSymbol *Fn); 307 308 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI); 309 310 void emitDebugInfoForRetainedTypes(); 311 312 void 313 emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs); 314 315 void emitDebugInfoForGlobals(); 316 void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals); 317 void emitDebugInfoForGlobal(const CVGlobalVariable &CVGV); 318 319 /// Opens a subsection of the given kind in a .debug$S codeview section. 320 /// Returns an end label for use with endCVSubsection when the subsection is 321 /// finished. 322 MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind); 323 void endCVSubsection(MCSymbol *EndLabel); 324 325 /// Opens a symbol record of the given kind. Returns an end label for use with 326 /// endSymbolRecord. 327 MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind); 328 void endSymbolRecord(MCSymbol *SymEnd); 329 330 /// Emits an S_END, S_INLINESITE_END, or S_PROC_ID_END record. These records 331 /// are empty, so we emit them with a simpler assembly sequence that doesn't 332 /// involve labels. 333 void emitEndSymbolRecord(codeview::SymbolKind EndKind); 334 335 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt, 336 const InlineSite &Site); 337 338 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 339 340 void collectGlobalVariableInfo(); 341 void collectVariableInfo(const DISubprogram *SP); 342 343 void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed); 344 345 // Construct the lexical block tree for a routine, pruning emptpy lexical 346 // scopes, and populate it with local variables. 347 void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes, 348 SmallVectorImpl<LexicalBlock *> &Blocks, 349 SmallVectorImpl<LocalVariable> &Locals, 350 SmallVectorImpl<CVGlobalVariable> &Globals); 351 void collectLexicalBlockInfo(LexicalScope &Scope, 352 SmallVectorImpl<LexicalBlock *> &ParentBlocks, 353 SmallVectorImpl<LocalVariable> &ParentLocals, 354 SmallVectorImpl<CVGlobalVariable> &ParentGlobals); 355 356 /// Records information about a local variable in the appropriate scope. In 357 /// particular, locals from inlined code live inside the inlining site. 358 void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS); 359 360 /// Emits local variables in the appropriate order. 361 void emitLocalVariableList(const FunctionInfo &FI, 362 ArrayRef<LocalVariable> Locals); 363 364 /// Emits an S_LOCAL record and its associated defined ranges. 365 void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var); 366 367 /// Emits a sequence of lexical block scopes and their children. 368 void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks, 369 const FunctionInfo& FI); 370 371 /// Emit a lexical block scope and its children. 372 void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI); 373 374 /// Translates the DIType to codeview if necessary and returns a type index 375 /// for it. 376 codeview::TypeIndex getTypeIndex(const DIType *Ty, 377 const DIType *ClassTy = nullptr); 378 379 codeview::TypeIndex 380 getTypeIndexForThisPtr(const DIDerivedType *PtrTy, 381 const DISubroutineType *SubroutineTy); 382 383 codeview::TypeIndex getTypeIndexForReferenceTo(const DIType *Ty); 384 385 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP, 386 const DICompositeType *Class); 387 388 codeview::TypeIndex getScopeIndex(const DIScope *Scope); 389 390 codeview::TypeIndex getVBPTypeIndex(); 391 392 void addToUDTs(const DIType *Ty); 393 394 void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI); 395 396 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy); 397 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty); 398 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty); 399 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty); 400 codeview::TypeIndex lowerTypePointer( 401 const DIDerivedType *Ty, 402 codeview::PointerOptions PO = codeview::PointerOptions::None); 403 codeview::TypeIndex lowerTypeMemberPointer( 404 const DIDerivedType *Ty, 405 codeview::PointerOptions PO = codeview::PointerOptions::None); 406 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty); 407 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty); 408 codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty); 409 codeview::TypeIndex lowerTypeMemberFunction( 410 const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment, 411 bool IsStaticMethod, 412 codeview::FunctionOptions FO = codeview::FunctionOptions::None); 413 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty); 414 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty); 415 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty); 416 417 /// Symbol records should point to complete types, but type records should 418 /// always point to incomplete types to avoid cycles in the type graph. Only 419 /// use this entry point when generating symbol records. The complete and 420 /// incomplete type indices only differ for record types. All other types use 421 /// the same index. 422 codeview::TypeIndex getCompleteTypeIndex(const DIType *Ty); 423 424 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty); 425 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty); 426 427 struct TypeLoweringScope; 428 429 void emitDeferredCompleteTypes(); 430 431 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy); 432 ClassInfo collectClassInfo(const DICompositeType *Ty); 433 434 /// Common record member lowering functionality for record types, which are 435 /// structs, classes, and unions. Returns the field list index and the member 436 /// count. 437 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool> 438 lowerRecordFieldList(const DICompositeType *Ty); 439 440 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates. 441 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node, 442 codeview::TypeIndex TI, 443 const DIType *ClassTy = nullptr); 444 445 unsigned getPointerSizeInBytes(); 446 447 protected: 448 /// Gather pre-function debug information. 449 void beginFunctionImpl(const MachineFunction *MF) override; 450 451 /// Gather post-function debug information. 452 void endFunctionImpl(const MachineFunction *) override; 453 454 public: 455 CodeViewDebug(AsmPrinter *AP); 456 457 void setSymbolSize(const MCSymbol *, uint64_t) override {} 458 459 /// Emit the COFF section that holds the line table information. 460 void endModule() override; 461 462 /// Process beginning of an instruction. 463 void beginInstruction(const MachineInstr *MI) override; 464 }; 465 466 } // end namespace llvm 467 468 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 469