lib/CodeGen/AsmPrinter/CodeViewDebug.h

   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 "DbgValueHistoryCalculator.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/TypeIndex.h"
  27 #include "llvm/DebugInfo/CodeView/TypeTableBuilder.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 /// \brief 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::TypeTableBuilder TypeTable;
  56
  57   /// Represents the most general definition range.
  58   struct LocalVarDefRange {
  59     /// Indicates that variable data is stored in memory relative to the
  60     /// specified register.
  61     int InMemory : 1;
  62
  63     /// Offset of variable data in memory.
  64     int DataOffset : 31;
  65
  66     /// Non-zero if this is a piece of an aggregate.
  67     uint16_t IsSubfield : 1;
  68
  69     /// Offset into aggregate.
  70     uint16_t StructOffset : 15;
  71
  72     /// Register containing the data or the register base of the memory
  73     /// location containing the data.
  74     uint16_t CVRegister;
  75
  76     /// Compares all location fields. This includes all fields except the label
  77     /// ranges.
  78     bool isDifferentLocation(LocalVarDefRange &O) {
  79       return InMemory != O.InMemory || DataOffset != O.DataOffset ||
  80              IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
  81              CVRegister != O.CVRegister;
  82     }
  83
  84     SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1> Ranges;
  85   };
  86
  87   static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
  88   static LocalVarDefRange createDefRangeGeneral(uint16_t CVRegister,
  89                                                 bool InMemory, int Offset,
  90                                                 bool IsSubfield,
  91                                                 uint16_t StructOffset);
  92
  93   /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
  94   struct LocalVariable {
  95     const DILocalVariable *DIVar = nullptr;
  96     SmallVector<LocalVarDefRange, 1> DefRanges;
  97     bool UseReferenceType = false;
  98   };
  99
 100   struct InlineSite {
 101     SmallVector<LocalVariable, 1> InlinedLocals;
 102     SmallVector<const DILocation *, 1> ChildSites;
 103     const DISubprogram *Inlinee = nullptr;
 104
 105     /// The ID of the inline site or function used with .cv_loc. Not a type
 106     /// index.
 107     unsigned SiteFuncId = 0;
 108   };
 109
 110   // For each function, store a vector of labels to its instructions, as well as
 111   // to the end of the function.
 112   struct FunctionInfo {
 113     /// Map from inlined call site to inlined instructions and child inlined
 114     /// call sites. Listed in program order.
 115     std::unordered_map<const DILocation *, InlineSite> InlineSites;
 116
 117     /// Ordered list of top-level inlined call sites.
 118     SmallVector<const DILocation *, 1> ChildSites;
 119
 120     SmallVector<LocalVariable, 1> Locals;
 121
 122     std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
 123
 124     const MCSymbol *Begin = nullptr;
 125     const MCSymbol *End = nullptr;
 126     unsigned FuncId = 0;
 127     unsigned LastFileId = 0;
 128     bool HaveLineInfo = false;
 129   };
 130   FunctionInfo *CurFn = nullptr;
 131
 132   /// The set of comdat .debug$S sections that we've seen so far. Each section
 133   /// must start with a magic version number that must only be emitted once.
 134   /// This set tracks which sections we've already opened.
 135   DenseSet<MCSectionCOFF *> ComdatDebugSections;
 136
 137   /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
 138   /// of an emitted global value, is in a comdat COFF section, this will switch
 139   /// to a new .debug$S section in that comdat. This method ensures that the
 140   /// section starts with the magic version number on first use. If GVSym is
 141   /// null, uses the main .debug$S section.
 142   void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
 143
 144   /// The next available function index for use with our .cv_* directives. Not
 145   /// to be confused with type indices for LF_FUNC_ID records.
 146   unsigned NextFuncId = 0;
 147
 148   InlineSite &getInlineSite(const DILocation *InlinedAt,
 149                             const DISubprogram *Inlinee);
 150
 151   codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
 152
 153   void calculateRanges(LocalVariable &Var,
 154                        const DbgValueHistoryMap::InstrRanges &Ranges);
 155
 156   static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
 157                                         const FunctionInfo &FI,
 158                                         const InlineSite &Site);
 159
 160   /// Remember some debug info about each function. Keep it in a stable order to
 161   /// emit at the end of the TU.
 162   MapVector<const Function *, FunctionInfo> FnDebugInfo;
 163
 164   /// Map from DIFile to .cv_file id.
 165   DenseMap<const DIFile *, unsigned> FileIdMap;
 166
 167   /// All inlined subprograms in the order they should be emitted.
 168   SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
 169
 170   /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
 171   /// be nullptr, to CodeView type indices. Primarily indexed by
 172   /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
 173   ///
 174   /// The second entry in the key is needed for methods as DISubroutineType
 175   /// representing static method type are shared with non-method function type.
 176   DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex>
 177       TypeIndices;
 178
 179   /// Map from DICompositeType* to complete type index. Non-record types are
 180   /// always looked up in the normal TypeIndices map.
 181   DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices;
 182
 183   /// Complete record types to emit after all active type lowerings are
 184   /// finished.
 185   SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
 186
 187   /// Number of type lowering frames active on the stack.
 188   unsigned TypeEmissionLevel = 0;
 189
 190   codeview::TypeIndex VBPType;
 191
 192   const DISubprogram *CurrentSubprogram = nullptr;
 193
 194   // The UDTs we have seen while processing types; each entry is a pair of type
 195   // index and type name.
 196   std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
 197   std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
 198
 199   using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
 200   FileToFilepathMapTy FileToFilepathMap;
 201
 202   StringRef getFullFilepath(const DIFile *S);
 203
 204   unsigned maybeRecordFile(const DIFile *F);
 205
 206   void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
 207
 208   void clear();
 209
 210   void setCurrentSubprogram(const DISubprogram *SP) {
 211     CurrentSubprogram = SP;
 212     LocalUDTs.clear();
 213   }
 214
 215   /// Emit the magic version number at the start of a CodeView type or symbol
 216   /// section. Appears at the front of every .debug$S or .debug$T section.
 217   void emitCodeViewMagicVersion();
 218
 219   void emitTypeInformation();
 220
 221   void emitCompilerInformation();
 222
 223   void emitInlineeLinesSubsection();
 224
 225   void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
 226
 227   void emitDebugInfoForGlobals();
 228
 229   void emitDebugInfoForRetainedTypes();
 230
 231   void
 232   emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs);
 233
 234   void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV,
 235                               const GlobalVariable *GV, MCSymbol *GVSym);
 236
 237   /// Opens a subsection of the given kind in a .debug$S codeview section.
 238   /// Returns an end label for use with endCVSubsection when the subsection is
 239   /// finished.
 240   MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
 241
 242   void endCVSubsection(MCSymbol *EndLabel);
 243
 244   void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
 245                            const InlineSite &Site);
 246
 247   using InlinedVariable = DbgValueHistoryMap::InlinedVariable;
 248
 249   void collectVariableInfo(const DISubprogram *SP);
 250
 251   void collectVariableInfoFromMFTable(DenseSet<InlinedVariable> &Processed);
 252
 253   /// Records information about a local variable in the appropriate scope. In
 254   /// particular, locals from inlined code live inside the inlining site.
 255   void recordLocalVariable(LocalVariable &&Var, const DILocation *Loc);
 256
 257   /// Emits local variables in the appropriate order.
 258   void emitLocalVariableList(ArrayRef<LocalVariable> Locals);
 259
 260   /// Emits an S_LOCAL record and its associated defined ranges.
 261   void emitLocalVariable(const LocalVariable &Var);
 262
 263   /// Translates the DIType to codeview if necessary and returns a type index
 264   /// for it.
 265   codeview::TypeIndex getTypeIndex(DITypeRef TypeRef,
 266                                    DITypeRef ClassTyRef = DITypeRef());
 267
 268   codeview::TypeIndex getTypeIndexForReferenceTo(DITypeRef TypeRef);
 269
 270   codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
 271                                             const DICompositeType *Class);
 272
 273   codeview::TypeIndex getScopeIndex(const DIScope *Scope);
 274
 275   codeview::TypeIndex getVBPTypeIndex();
 276
 277   void addToUDTs(const DIType *Ty);
 278
 279   codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
 280   codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
 281   codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
 282   codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
 283   codeview::TypeIndex lowerTypePointer(const DIDerivedType *Ty);
 284   codeview::TypeIndex lowerTypeMemberPointer(const DIDerivedType *Ty);
 285   codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
 286   codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
 287   codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
 288   codeview::TypeIndex lowerTypeMemberFunction(const DISubroutineType *Ty,
 289                                               const DIType *ClassTy,
 290                                               int ThisAdjustment,
 291                                               bool IsStaticMethod);
 292   codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
 293   codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
 294   codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
 295
 296   /// Symbol records should point to complete types, but type records should
 297   /// always point to incomplete types to avoid cycles in the type graph. Only
 298   /// use this entry point when generating symbol records. The complete and
 299   /// incomplete type indices only differ for record types. All other types use
 300   /// the same index.
 301   codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef);
 302
 303   codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
 304   codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
 305
 306   struct TypeLoweringScope;
 307
 308   void emitDeferredCompleteTypes();
 309
 310   void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
 311   ClassInfo collectClassInfo(const DICompositeType *Ty);
 312
 313   /// Common record member lowering functionality for record types, which are
 314   /// structs, classes, and unions. Returns the field list index and the member
 315   /// count.
 316   std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
 317   lowerRecordFieldList(const DICompositeType *Ty);
 318
 319   /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
 320   codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
 321                                                codeview::TypeIndex TI,
 322                                                const DIType *ClassTy = nullptr);
 323
 324   unsigned getPointerSizeInBytes();
 325
 326 protected:
 327   /// \brief Gather pre-function debug information.
 328   void beginFunctionImpl(const MachineFunction *MF) override;
 329
 330   /// \brief Gather post-function debug information.
 331   void endFunctionImpl(const MachineFunction *) override;
 332
 333 public:
 334   CodeViewDebug(AsmPrinter *Asm);
 335
 336   void setSymbolSize(const MCSymbol *, uint64_t) override {}
 337
 338   /// \brief Emit the COFF section that holds the line table information.
 339   void endModule() override;
 340
 341   /// \brief Process beginning of an instruction.
 342   void beginInstruction(const MachineInstr *MI) override;
 343 };
 344
 345 } // end namespace llvm
 346
 347 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H