src/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.h

   1 //===-- llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.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 line tables info into COFF files.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WINCODEVIEWLINETABLES_H
  15 #define LLVM_LIB_CODEGEN_ASMPRINTER_WINCODEVIEWLINETABLES_H
  16
  17 #include "AsmPrinterHandler.h"
  18 #include "llvm/ADT/DenseMap.h"
  19 #include "llvm/ADT/StringMap.h"
  20 #include "llvm/ADT/StringRef.h"
  21 #include "llvm/CodeGen/AsmPrinter.h"
  22 #include "llvm/CodeGen/LexicalScopes.h"
  23 #include "llvm/CodeGen/MachineFunction.h"
  24 #include "llvm/CodeGen/MachineModuleInfo.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 /// \brief Collects and handles line tables information in a CodeView format.
  32 class WinCodeViewLineTables : public AsmPrinterHandler {
  33   AsmPrinter *Asm;
  34   DebugLoc PrevInstLoc;
  35
  36   // For each function, store a vector of labels to its instructions, as well as
  37   // to the end of the function.
  38   struct FunctionInfo {
  39     SmallVector<MCSymbol *, 10> Instrs;
  40     MCSymbol *End;
  41     FunctionInfo() : End(nullptr) {}
  42   } *CurFn;
  43
  44   typedef DenseMap<const Function *, FunctionInfo> FnDebugInfoTy;
  45   FnDebugInfoTy FnDebugInfo;
  46   // Store the functions we've visited in a vector so we can maintain a stable
  47   // order while emitting subsections.
  48   SmallVector<const Function *, 10> VisitedFunctions;
  49
  50   // InstrInfoTy - Holds the Filename:LineNumber information for every
  51   // instruction with a unique debug location.
  52   struct InstrInfoTy {
  53     StringRef Filename;
  54     unsigned LineNumber;
  55
  56     InstrInfoTy() : LineNumber(0) {}
  57
  58     InstrInfoTy(StringRef Filename, unsigned LineNumber)
  59         : Filename(Filename), LineNumber(LineNumber) {}
  60   };
  61   DenseMap<MCSymbol *, InstrInfoTy> InstrInfo;
  62
  63   // FileNameRegistry - Manages filenames observed while generating debug info
  64   // by filtering out duplicates and bookkeeping the offsets in the string
  65   // table to be generated.
  66   struct FileNameRegistryTy {
  67     SmallVector<StringRef, 10> Filenames;
  68     struct PerFileInfo {
  69       size_t FilenameID, StartOffset;
  70     };
  71     StringMap<PerFileInfo> Infos;
  72
  73     // The offset in the string table where we'll write the next unique
  74     // filename.
  75     size_t LastOffset;
  76
  77     FileNameRegistryTy() {
  78       clear();
  79     }
  80
  81     // Add Filename to the registry, if it was not observed before.
  82     void add(StringRef Filename) {
  83       if (Infos.count(Filename))
  84         return;
  85       size_t OldSize = Infos.size();
  86       Infos[Filename].FilenameID = OldSize;
  87       Infos[Filename].StartOffset = LastOffset;
  88       LastOffset += Filename.size() + 1;
  89       Filenames.push_back(Filename);
  90     }
  91
  92     void clear() {
  93       LastOffset = 1;
  94       Infos.clear();
  95       Filenames.clear();
  96     }
  97   } FileNameRegistry;
  98
  99   typedef std::map<std::pair<StringRef, StringRef>, char *>
 100       DirAndFilenameToFilepathMapTy;
 101   DirAndFilenameToFilepathMapTy DirAndFilenameToFilepathMap;
 102   StringRef getFullFilepath(const MDNode *S);
 103
 104   void maybeRecordLocation(DebugLoc DL, const MachineFunction *MF);
 105
 106   void clear() {
 107     assert(CurFn == nullptr);
 108     FileNameRegistry.clear();
 109     InstrInfo.clear();
 110   }
 111
 112   void emitDebugInfoForFunction(const Function *GV);
 113
 114 public:
 115   WinCodeViewLineTables(AsmPrinter *Asm);
 116
 117   ~WinCodeViewLineTables() {
 118     for (DirAndFilenameToFilepathMapTy::iterator
 119              I = DirAndFilenameToFilepathMap.begin(),
 120              E = DirAndFilenameToFilepathMap.end();
 121          I != E; ++I)
 122       free(I->second);
 123   }
 124
 125   void setSymbolSize(const llvm::MCSymbol *, uint64_t) override {}
 126
 127   /// \brief Emit the COFF section that holds the line table information.
 128   void endModule() override;
 129
 130   /// \brief Gather pre-function debug information.
 131   void beginFunction(const MachineFunction *MF) override;
 132
 133   /// \brief Gather post-function debug information.
 134   void endFunction(const MachineFunction *) override;
 135
 136   /// \brief Process beginning of an instruction.
 137   void beginInstruction(const MachineInstr *MI) override;
 138
 139   /// \brief Process end of an instruction.
 140   void endInstruction() override {}
 141 };
 142 } // End of namespace llvm
 143
 144 #endif