WinCodeViewLineTables.h revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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 CODEGEN_ASMPRINTER_WINCODEVIEWLINETABLES_H__
15#define 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
30namespace llvm {
31/// \brief Collects and handles line tables information in a CodeView format.
32class 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(0) {}
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 == 0);
108    FileNameRegistry.clear();
109    InstrInfo.clear();
110  }
111
112  void emitDebugInfoForFunction(const Function *GV);
113
114public:
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
145