1 //===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains support for writing Microsoft CodeView debug info. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 15 #define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 16 17 #include "DbgEntityHistoryCalculator.h" 18 #include "DebugHandlerBase.h" 19 #include "llvm/ADT/ArrayRef.h" 20 #include "llvm/ADT/DenseMap.h" 21 #include "llvm/ADT/DenseSet.h" 22 #include "llvm/ADT/MapVector.h" 23 #include "llvm/ADT/SetVector.h" 24 #include "llvm/ADT/SmallVector.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 InlineSite { 103 SmallVector<LocalVariable, 1> InlinedLocals; 104 SmallVector<const DILocation *, 1> ChildSites; 105 const DISubprogram *Inlinee = nullptr; 106 107 /// The ID of the inline site or function used with .cv_loc. Not a type 108 /// index. 109 unsigned SiteFuncId = 0; 110 }; 111 112 // Combines information from DILexicalBlock and LexicalScope. 113 struct LexicalBlock { 114 SmallVector<LocalVariable, 1> Locals; 115 SmallVector<LexicalBlock *, 1> Children; 116 const MCSymbol *Begin; 117 const MCSymbol *End; 118 StringRef Name; 119 }; 120 121 // For each function, store a vector of labels to its instructions, as well as 122 // to the end of the function. 123 struct FunctionInfo { 124 FunctionInfo() = default; 125 126 // Uncopyable. 127 FunctionInfo(const FunctionInfo &FI) = delete; 128 129 /// Map from inlined call site to inlined instructions and child inlined 130 /// call sites. Listed in program order. 131 std::unordered_map<const DILocation *, InlineSite> InlineSites; 132 133 /// Ordered list of top-level inlined call sites. 134 SmallVector<const DILocation *, 1> ChildSites; 135 136 SmallVector<LocalVariable, 1> Locals; 137 138 std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks; 139 140 // Lexical blocks containing local variables. 141 SmallVector<LexicalBlock *, 1> ChildBlocks; 142 143 std::vector<std::pair<MCSymbol *, MDNode *>> Annotations; 144 145 const MCSymbol *Begin = nullptr; 146 const MCSymbol *End = nullptr; 147 unsigned FuncId = 0; 148 unsigned LastFileId = 0; 149 150 /// Number of bytes allocated in the prologue for all local stack objects. 151 unsigned FrameSize = 0; 152 153 /// Number of bytes of parameters on the stack. 154 unsigned ParamSize = 0; 155 156 /// Number of bytes pushed to save CSRs. 157 unsigned CSRSize = 0; 158 159 /// Adjustment to apply on x86 when using the VFRAME frame pointer. 160 int OffsetAdjustment = 0; 161 162 /// Two-bit value indicating which register is the designated frame pointer 163 /// register for local variables. Included in S_FRAMEPROC. 164 codeview::EncodedFramePtrReg EncodedLocalFramePtrReg = 165 codeview::EncodedFramePtrReg::None; 166 167 /// Two-bit value indicating which register is the designated frame pointer 168 /// register for stack parameters. Included in S_FRAMEPROC. 169 codeview::EncodedFramePtrReg EncodedParamFramePtrReg = 170 codeview::EncodedFramePtrReg::None; 171 172 codeview::FrameProcedureOptions FrameProcOpts; 173 174 bool HasStackRealignment = false; 175 176 bool HaveLineInfo = false; 177 }; 178 FunctionInfo *CurFn = nullptr; 179 180 // Map used to seperate variables according to the lexical scope they belong 181 // in. This is populated by recordLocalVariable() before 182 // collectLexicalBlocks() separates the variables between the FunctionInfo 183 // and LexicalBlocks. 184 DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables; 185 186 /// The set of comdat .debug$S sections that we've seen so far. Each section 187 /// must start with a magic version number that must only be emitted once. 188 /// This set tracks which sections we've already opened. 189 DenseSet<MCSectionCOFF *> ComdatDebugSections; 190 191 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol 192 /// of an emitted global value, is in a comdat COFF section, this will switch 193 /// to a new .debug$S section in that comdat. This method ensures that the 194 /// section starts with the magic version number on first use. If GVSym is 195 /// null, uses the main .debug$S section. 196 void switchToDebugSectionForSymbol(const MCSymbol *GVSym); 197 198 /// The next available function index for use with our .cv_* directives. Not 199 /// to be confused with type indices for LF_FUNC_ID records. 200 unsigned NextFuncId = 0; 201 202 InlineSite &getInlineSite(const DILocation *InlinedAt, 203 const DISubprogram *Inlinee); 204 205 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP); 206 207 void calculateRanges(LocalVariable &Var, 208 const DbgValueHistoryMap::InstrRanges &Ranges); 209 210 static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children, 211 const FunctionInfo &FI, 212 const InlineSite &Site); 213 214 /// Remember some debug info about each function. Keep it in a stable order to 215 /// emit at the end of the TU. 216 MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo; 217 218 /// Map from full file path to .cv_file id. Full paths are built from DIFiles 219 /// and are stored in FileToFilepathMap; 220 DenseMap<StringRef, unsigned> FileIdMap; 221 222 /// All inlined subprograms in the order they should be emitted. 223 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms; 224 225 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can 226 /// be nullptr, to CodeView type indices. Primarily indexed by 227 /// {DIType*, DIType*} and {DISubprogram*, DIType*}. 228 /// 229 /// The second entry in the key is needed for methods as DISubroutineType 230 /// representing static method type are shared with non-method function type. 231 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex> 232 TypeIndices; 233 234 /// Map from DICompositeType* to complete type index. Non-record types are 235 /// always looked up in the normal TypeIndices map. 236 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices; 237 238 /// Complete record types to emit after all active type lowerings are 239 /// finished. 240 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes; 241 242 /// Number of type lowering frames active on the stack. 243 unsigned TypeEmissionLevel = 0; 244 245 codeview::TypeIndex VBPType; 246 247 const DISubprogram *CurrentSubprogram = nullptr; 248 249 // The UDTs we have seen while processing types; each entry is a pair of type 250 // index and type name. 251 std::vector<std::pair<std::string, const DIType *>> LocalUDTs; 252 std::vector<std::pair<std::string, const DIType *>> GlobalUDTs; 253 254 using FileToFilepathMapTy = std::map<const DIFile *, std::string>; 255 FileToFilepathMapTy FileToFilepathMap; 256 257 StringRef getFullFilepath(const DIFile *File); 258 259 unsigned maybeRecordFile(const DIFile *F); 260 261 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF); 262 263 void clear(); 264 265 void setCurrentSubprogram(const DISubprogram *SP) { 266 CurrentSubprogram = SP; 267 LocalUDTs.clear(); 268 } 269 270 /// Emit the magic version number at the start of a CodeView type or symbol 271 /// section. Appears at the front of every .debug$S or .debug$T or .debug$P 272 /// section. 273 void emitCodeViewMagicVersion(); 274 275 void emitTypeInformation(); 276 277 void emitTypeGlobalHashes(); 278 279 void emitCompilerInformation(); 280 281 void emitBuildInfo(); 282 283 void emitInlineeLinesSubsection(); 284 285 void emitDebugInfoForThunk(const Function *GV, 286 FunctionInfo &FI, 287 const MCSymbol *Fn); 288 289 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI); 290 291 void emitDebugInfoForGlobals(); 292 293 void emitDebugInfoForRetainedTypes(); 294 295 void 296 emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs); 297 298 void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, 299 const GlobalVariable *GV, MCSymbol *GVSym); 300 301 /// Opens a subsection of the given kind in a .debug$S codeview section. 302 /// Returns an end label for use with endCVSubsection when the subsection is 303 /// finished. 304 MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind); 305 306 void endCVSubsection(MCSymbol *EndLabel); 307 308 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt, 309 const InlineSite &Site); 310 311 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 312 313 void collectVariableInfo(const DISubprogram *SP); 314 315 void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed); 316 317 // Construct the lexical block tree for a routine, pruning emptpy lexical 318 // scopes, and populate it with local variables. 319 void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes, 320 SmallVectorImpl<LexicalBlock *> &Blocks, 321 SmallVectorImpl<LocalVariable> &Locals); 322 void collectLexicalBlockInfo(LexicalScope &Scope, 323 SmallVectorImpl<LexicalBlock *> &ParentBlocks, 324 SmallVectorImpl<LocalVariable> &ParentLocals); 325 326 /// Records information about a local variable in the appropriate scope. In 327 /// particular, locals from inlined code live inside the inlining site. 328 void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS); 329 330 /// Emits local variables in the appropriate order. 331 void emitLocalVariableList(const FunctionInfo &FI, 332 ArrayRef<LocalVariable> Locals); 333 334 /// Emits an S_LOCAL record and its associated defined ranges. 335 void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var); 336 337 /// Emits a sequence of lexical block scopes and their children. 338 void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks, 339 const FunctionInfo& FI); 340 341 /// Emit a lexical block scope and its children. 342 void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI); 343 344 /// Translates the DIType to codeview if necessary and returns a type index 345 /// for it. 346 codeview::TypeIndex getTypeIndex(DITypeRef TypeRef, 347 DITypeRef ClassTyRef = DITypeRef()); 348 349 codeview::TypeIndex 350 getTypeIndexForThisPtr(DITypeRef TypeRef, 351 const DISubroutineType *SubroutineTy); 352 353 codeview::TypeIndex getTypeIndexForReferenceTo(DITypeRef TypeRef); 354 355 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP, 356 const DICompositeType *Class); 357 358 codeview::TypeIndex getScopeIndex(const DIScope *Scope); 359 360 codeview::TypeIndex getVBPTypeIndex(); 361 362 void addToUDTs(const DIType *Ty); 363 364 void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI); 365 366 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy); 367 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty); 368 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty); 369 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty); 370 codeview::TypeIndex lowerTypePointer( 371 const DIDerivedType *Ty, 372 codeview::PointerOptions PO = codeview::PointerOptions::None); 373 codeview::TypeIndex lowerTypeMemberPointer( 374 const DIDerivedType *Ty, 375 codeview::PointerOptions PO = codeview::PointerOptions::None); 376 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty); 377 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty); 378 codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty); 379 codeview::TypeIndex lowerTypeMemberFunction( 380 const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment, 381 bool IsStaticMethod, 382 codeview::FunctionOptions FO = codeview::FunctionOptions::None); 383 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty); 384 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty); 385 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty); 386 387 /// Symbol records should point to complete types, but type records should 388 /// always point to incomplete types to avoid cycles in the type graph. Only 389 /// use this entry point when generating symbol records. The complete and 390 /// incomplete type indices only differ for record types. All other types use 391 /// the same index. 392 codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef); 393 394 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty); 395 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty); 396 397 struct TypeLoweringScope; 398 399 void emitDeferredCompleteTypes(); 400 401 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy); 402 ClassInfo collectClassInfo(const DICompositeType *Ty); 403 404 /// Common record member lowering functionality for record types, which are 405 /// structs, classes, and unions. Returns the field list index and the member 406 /// count. 407 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool> 408 lowerRecordFieldList(const DICompositeType *Ty); 409 410 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates. 411 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node, 412 codeview::TypeIndex TI, 413 const DIType *ClassTy = nullptr); 414 415 unsigned getPointerSizeInBytes(); 416 417 protected: 418 /// Gather pre-function debug information. 419 void beginFunctionImpl(const MachineFunction *MF) override; 420 421 /// Gather post-function debug information. 422 void endFunctionImpl(const MachineFunction *) override; 423 424 public: 425 CodeViewDebug(AsmPrinter *AP); 426 427 void setSymbolSize(const MCSymbol *, uint64_t) override {} 428 429 /// Emit the COFF section that holds the line table information. 430 void endModule() override; 431 432 /// Process beginning of an instruction. 433 void beginInstruction(const MachineInstr *MI) override; 434 }; 435 436 } // end namespace llvm 437 438 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H 439