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 "DebugHandlerBase.h" 18 #include "llvm/ADT/DenseMap.h" 19 #include "llvm/ADT/StringMap.h" 20 #include "llvm/CodeGen/AsmPrinter.h" 21 #include "llvm/CodeGen/MachineFunction.h" 22 #include "llvm/CodeGen/MachineModuleInfo.h" 23 #include "llvm/DebugInfo/CodeView/MemoryTypeTableBuilder.h" 24 #include "llvm/DebugInfo/CodeView/TypeIndex.h" 25 #include "llvm/IR/DebugInfo.h" 26 #include "llvm/IR/DebugLoc.h" 27 #include "llvm/MC/MCStreamer.h" 28 #include "llvm/Target/TargetLoweringObjectFile.h" 29 30 namespace llvm { 31 32 class StringRef; 33 class LexicalScope; 34 struct ClassInfo; 35 36 /// \brief Collects and handles line tables information in a CodeView format. 37 class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase { 38 MCStreamer &OS; 39 codeview::MemoryTypeTableBuilder TypeTable; 40 41 /// Represents the most general definition range. 42 struct LocalVarDefRange { 43 /// Indicates that variable data is stored in memory relative to the 44 /// specified register. 45 int InMemory : 1; 46 47 /// Offset of variable data in memory. 48 int DataOffset : 31; 49 50 /// Offset of the data into the user level struct. If zero, no splitting 51 /// occurred. 52 uint16_t StructOffset; 53 54 /// Register containing the data or the register base of the memory 55 /// location containing the data. 56 uint16_t CVRegister; 57 58 /// Compares all location fields. This includes all fields except the label 59 /// ranges. 60 bool isDifferentLocation(LocalVarDefRange &O) { 61 return InMemory != O.InMemory || DataOffset != O.DataOffset || 62 StructOffset != O.StructOffset || CVRegister != O.CVRegister; 63 } 64 65 SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1> Ranges; 66 }; 67 68 static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset); 69 static LocalVarDefRange createDefRangeReg(uint16_t CVRegister); 70 71 /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific. 72 struct LocalVariable { 73 const DILocalVariable *DIVar = nullptr; 74 SmallVector<LocalVarDefRange, 1> DefRanges; 75 }; 76 77 struct InlineSite { 78 SmallVector<LocalVariable, 1> InlinedLocals; 79 SmallVector<const DILocation *, 1> ChildSites; 80 const DISubprogram *Inlinee = nullptr; 81 82 /// The ID of the inline site or function used with .cv_loc. Not a type 83 /// index. 84 unsigned SiteFuncId = 0; 85 }; 86 87 // For each function, store a vector of labels to its instructions, as well as 88 // to the end of the function. 89 struct FunctionInfo { 90 /// Map from inlined call site to inlined instructions and child inlined 91 /// call sites. Listed in program order. 92 std::unordered_map<const DILocation *, InlineSite> InlineSites; 93 94 /// Ordered list of top-level inlined call sites. 95 SmallVector<const DILocation *, 1> ChildSites; 96 97 SmallVector<LocalVariable, 1> Locals; 98 99 DebugLoc LastLoc; 100 const MCSymbol *Begin = nullptr; 101 const MCSymbol *End = nullptr; 102 unsigned FuncId = 0; 103 unsigned LastFileId = 0; 104 bool HaveLineInfo = false; 105 }; 106 FunctionInfo *CurFn; 107 108 /// The set of comdat .debug$S sections that we've seen so far. Each section 109 /// must start with a magic version number that must only be emitted once. 110 /// This set tracks which sections we've already opened. 111 DenseSet<MCSectionCOFF *> ComdatDebugSections; 112 113 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol 114 /// of an emitted global value, is in a comdat COFF section, this will switch 115 /// to a new .debug$S section in that comdat. This method ensures that the 116 /// section starts with the magic version number on first use. If GVSym is 117 /// null, uses the main .debug$S section. 118 void switchToDebugSectionForSymbol(const MCSymbol *GVSym); 119 120 /// The next available function index for use with our .cv_* directives. Not 121 /// to be confused with type indices for LF_FUNC_ID records. 122 unsigned NextFuncId = 0; 123 124 InlineSite &getInlineSite(const DILocation *InlinedAt, 125 const DISubprogram *Inlinee); 126 127 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP); 128 129 static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children, 130 const FunctionInfo &FI, 131 const InlineSite &Site); 132 133 /// Remember some debug info about each function. Keep it in a stable order to 134 /// emit at the end of the TU. 135 MapVector<const Function *, FunctionInfo> FnDebugInfo; 136 137 /// Map from DIFile to .cv_file id. 138 DenseMap<const DIFile *, unsigned> FileIdMap; 139 140 /// All inlined subprograms in the order they should be emitted. 141 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms; 142 143 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can 144 /// be nullptr, to CodeView type indices. Primarily indexed by 145 /// {DIType*, DIType*} and {DISubprogram*, DIType*}. 146 /// 147 /// The second entry in the key is needed for methods as DISubroutineType 148 /// representing static method type are shared with non-method function type. 149 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex> 150 TypeIndices; 151 152 /// Map from DICompositeType* to complete type index. Non-record types are 153 /// always looked up in the normal TypeIndices map. 154 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices; 155 156 /// Complete record types to emit after all active type lowerings are 157 /// finished. 158 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes; 159 160 /// Number of type lowering frames active on the stack. 161 unsigned TypeEmissionLevel = 0; 162 163 codeview::TypeIndex VBPType; 164 165 const DISubprogram *CurrentSubprogram = nullptr; 166 167 // The UDTs we have seen while processing types; each entry is a pair of type 168 // index and type name. 169 std::vector<std::pair<std::string, codeview::TypeIndex>> LocalUDTs, 170 GlobalUDTs; 171 172 typedef std::map<const DIFile *, std::string> FileToFilepathMapTy; 173 FileToFilepathMapTy FileToFilepathMap; 174 StringRef getFullFilepath(const DIFile *S); 175 176 unsigned maybeRecordFile(const DIFile *F); 177 178 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF); 179 180 void clear(); 181 182 void setCurrentSubprogram(const DISubprogram *SP) { 183 CurrentSubprogram = SP; 184 LocalUDTs.clear(); 185 } 186 187 /// Emit the magic version number at the start of a CodeView type or symbol 188 /// section. Appears at the front of every .debug$S or .debug$T section. 189 void emitCodeViewMagicVersion(); 190 191 void emitTypeInformation(); 192 193 void emitInlineeLinesSubsection(); 194 195 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI); 196 197 void emitDebugInfoForGlobals(); 198 199 void emitDebugInfoForRetainedTypes(); 200 201 void emitDebugInfoForUDTs( 202 ArrayRef<std::pair<std::string, codeview::TypeIndex>> UDTs); 203 204 void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, MCSymbol *GVSym); 205 206 /// Opens a subsection of the given kind in a .debug$S codeview section. 207 /// Returns an end label for use with endCVSubsection when the subsection is 208 /// finished. 209 MCSymbol *beginCVSubsection(codeview::ModuleSubstreamKind Kind); 210 211 void endCVSubsection(MCSymbol *EndLabel); 212 213 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt, 214 const InlineSite &Site); 215 216 typedef DbgValueHistoryMap::InlinedVariable InlinedVariable; 217 218 void collectVariableInfo(const DISubprogram *SP); 219 220 void collectVariableInfoFromMMITable(DenseSet<InlinedVariable> &Processed); 221 222 /// Records information about a local variable in the appropriate scope. In 223 /// particular, locals from inlined code live inside the inlining site. 224 void recordLocalVariable(LocalVariable &&Var, const DILocation *Loc); 225 226 /// Emits local variables in the appropriate order. 227 void emitLocalVariableList(ArrayRef<LocalVariable> Locals); 228 229 /// Emits an S_LOCAL record and its associated defined ranges. 230 void emitLocalVariable(const LocalVariable &Var); 231 232 /// Translates the DIType to codeview if necessary and returns a type index 233 /// for it. 234 codeview::TypeIndex getTypeIndex(DITypeRef TypeRef, 235 DITypeRef ClassTyRef = DITypeRef()); 236 237 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP, 238 const DICompositeType *Class); 239 240 codeview::TypeIndex getScopeIndex(const DIScope *Scope); 241 242 codeview::TypeIndex getVBPTypeIndex(); 243 244 void addToUDTs(const DIType *Ty, codeview::TypeIndex TI); 245 246 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy); 247 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty); 248 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty); 249 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty); 250 codeview::TypeIndex lowerTypePointer(const DIDerivedType *Ty); 251 codeview::TypeIndex lowerTypeMemberPointer(const DIDerivedType *Ty); 252 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty); 253 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty); 254 codeview::TypeIndex lowerTypeMemberFunction(const DISubroutineType *Ty, 255 const DIType *ClassTy, 256 int ThisAdjustment); 257 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty); 258 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty); 259 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty); 260 261 /// Symbol records should point to complete types, but type records should 262 /// always point to incomplete types to avoid cycles in the type graph. Only 263 /// use this entry point when generating symbol records. The complete and 264 /// incomplete type indices only differ for record types. All other types use 265 /// the same index. 266 codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef); 267 268 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty); 269 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty); 270 271 struct TypeLoweringScope; 272 273 void emitDeferredCompleteTypes(); 274 275 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy); 276 ClassInfo collectClassInfo(const DICompositeType *Ty); 277 278 /// Common record member lowering functionality for record types, which are 279 /// structs, classes, and unions. Returns the field list index and the member 280 /// count. 281 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool> 282 lowerRecordFieldList(const DICompositeType *Ty); 283 284 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates. 285 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node, 286 codeview::TypeIndex TI, 287 const DIType *ClassTy = nullptr); 288 289 unsigned getPointerSizeInBytes(); 290 291 public: 292 CodeViewDebug(AsmPrinter *Asm); 293 294 void setSymbolSize(const llvm::MCSymbol *, uint64_t) override {} 295 296 /// \brief Emit the COFF section that holds the line table information. 297 void endModule() override; 298 299 /// \brief Gather pre-function debug information. 300 void beginFunction(const MachineFunction *MF) override; 301 302 /// \brief Gather post-function debug information. 303 void endFunction(const MachineFunction *) override; 304 305 /// \brief Process beginning of an instruction. 306 void beginInstruction(const MachineInstr *MI) override; 307 }; 308 } // End of namespace llvm 309 310 #endif 311