sanitizer_symbolizer.h revision 276851 
1//===-- sanitizer_symbolizer.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// Symbolizer is used by sanitizers to map instruction address to a location in
11// source code at run-time. Symbolizer either uses __sanitizer_symbolize_*
12// defined in the program, or (if they are missing) tries to find and
13// launch "llvm-symbolizer" commandline tool in a separate process and
14// communicate with it.
15//
16// Generally we should try to avoid calling system library functions during
17// symbolization (and use their replacements from sanitizer_libc.h instead).
18//===----------------------------------------------------------------------===//
19#ifndef SANITIZER_SYMBOLIZER_H
20#define SANITIZER_SYMBOLIZER_H
21
22#include "sanitizer_common.h"
23#include "sanitizer_mutex.h"
24
25namespace __sanitizer {
26
27struct AddressInfo {
28  // Owns all the string members. Storage for them is
29  // (de)allocated using sanitizer internal allocator.
30  uptr address;
31
32  char *module;
33  uptr module_offset;
34
35  static const uptr kUnknown = ~(uptr)0;
36  char *function;
37  uptr function_offset;
38
39  char *file;
40  int line;
41  int column;
42
43  AddressInfo();
44  // Deletes all strings and resets all fields.
45  void Clear();
46  void FillAddressAndModuleInfo(uptr addr, const char *mod_name,
47                                uptr mod_offset);
48};
49
50// Linked list of symbolized frames (each frame is described by AddressInfo).
51struct SymbolizedStack {
52  SymbolizedStack *next;
53  AddressInfo info;
54  static SymbolizedStack *New(uptr addr);
55  // Deletes current, and all subsequent frames in the linked list.
56  // The object cannot be accessed after the call to this function.
57  void ClearAll();
58
59 private:
60  SymbolizedStack();
61};
62
63// For now, DataInfo is used to describe global variable.
64struct DataInfo {
65  // Owns all the string members. Storage for them is
66  // (de)allocated using sanitizer internal allocator.
67  char *module;
68  uptr module_offset;
69  char *name;
70  uptr start;
71  uptr size;
72
73  DataInfo();
74  void Clear();
75};
76
77class Symbolizer {
78 public:
79  /// Initialize and return platform-specific implementation of symbolizer
80  /// (if it wasn't already initialized).
81  static Symbolizer *GetOrInit();
82  // Returns a list of symbolized frames for a given address (containing
83  // all inlined functions, if necessary).
84  virtual SymbolizedStack *SymbolizePC(uptr address) {
85    return SymbolizedStack::New(address);
86  }
87  virtual bool SymbolizeData(uptr address, DataInfo *info) {
88    return false;
89  }
90  virtual bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
91                                           uptr *module_address) {
92    return false;
93  }
94  virtual bool CanReturnFileLineInfo() {
95    return false;
96  }
97  // Release internal caches (if any).
98  virtual void Flush() {}
99  // Attempts to demangle the provided C++ mangled name.
100  virtual const char *Demangle(const char *name) {
101    return name;
102  }
103  virtual void PrepareForSandboxing() {}
104
105  // Allow user to install hooks that would be called before/after Symbolizer
106  // does the actual file/line info fetching. Specific sanitizers may need this
107  // to distinguish system library calls made in user code from calls made
108  // during in-process symbolization.
109  typedef void (*StartSymbolizationHook)();
110  typedef void (*EndSymbolizationHook)();
111  // May be called at most once.
112  void AddHooks(StartSymbolizationHook start_hook,
113                EndSymbolizationHook end_hook);
114
115 private:
116  /// Platform-specific function for creating a Symbolizer object.
117  static Symbolizer *PlatformInit();
118  /// Initialize the symbolizer in a disabled state.  Not thread safe.
119  static Symbolizer *Disable();
120
121  static Symbolizer *symbolizer_;
122  static StaticSpinMutex init_mu_;
123
124 protected:
125  Symbolizer();
126
127  static LowLevelAllocator symbolizer_allocator_;
128
129  StartSymbolizationHook start_hook_;
130  EndSymbolizationHook end_hook_;
131  class SymbolizerScope {
132   public:
133    explicit SymbolizerScope(const Symbolizer *sym);
134    ~SymbolizerScope();
135   private:
136    const Symbolizer *sym_;
137  };
138};
139
140}  // namespace __sanitizer
141
142#endif  // SANITIZER_SYMBOLIZER_H
143