sanitizer_symbolizer.h revision 66d91e3356a0c4d7aff3beaaaff3e87bbaec805c 
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_allocator_internal.h"
23#include "sanitizer_internal_defs.h"
24#include "sanitizer_libc.h"
25
26namespace __sanitizer {
27
28struct AddressInfo {
29  uptr address;
30  char *module;
31  uptr module_offset;
32  char *function;
33  char *file;
34  int line;
35  int column;
36
37  AddressInfo() {
38    internal_memset(this, 0, sizeof(AddressInfo));
39  }
40
41  // Deletes all strings and sets all fields to zero.
42  void Clear() {
43    InternalFree(module);
44    InternalFree(function);
45    InternalFree(file);
46    internal_memset(this, 0, sizeof(AddressInfo));
47  }
48
49  void FillAddressAndModuleInfo(uptr addr, const char *mod_name,
50                                uptr mod_offset) {
51    address = addr;
52    module = internal_strdup(mod_name);
53    module_offset = mod_offset;
54  }
55};
56
57struct DataInfo {
58  uptr address;
59  char *module;
60  uptr module_offset;
61  char *name;
62  uptr start;
63  uptr size;
64};
65
66class Symbolizer {
67 public:
68  /// Returns platform-specific implementation of Symbolizer. The symbolizer
69  /// must be initialized (with init or disable) before calling this function.
70  static Symbolizer *Get();
71  /// Returns platform-specific implementation of Symbolizer, or null if not
72  /// initialized.
73  static Symbolizer *GetOrNull();
74  /// Returns platform-specific implementation of Symbolizer.  Will
75  /// automatically initialize symbolizer as if by calling Init(0) if needed.
76  static Symbolizer *GetOrInit();
77  /// Initialize and return the symbolizer, given an optional path to an
78  /// external symbolizer.  The path argument is only required for legacy
79  /// reasons as this function will check $PATH for an external symbolizer.  Not
80  /// thread safe.
81  static Symbolizer *Init(const char* path_to_external = 0);
82  /// Initialize the symbolizer in a disabled state.  Not thread safe.
83  static Symbolizer *Disable();
84  // Fills at most "max_frames" elements of "frames" with descriptions
85  // for a given address (in all inlined functions). Returns the number
86  // of descriptions actually filled.
87  virtual uptr SymbolizeCode(uptr address, AddressInfo *frames,
88                             uptr max_frames) {
89    return 0;
90  }
91  virtual bool SymbolizeData(uptr address, DataInfo *info) {
92    return false;
93  }
94  virtual bool IsAvailable() {
95    return false;
96  }
97  virtual bool IsExternalAvailable() {
98    return false;
99  }
100  // Release internal caches (if any).
101  virtual void Flush() {}
102  // Attempts to demangle the provided C++ mangled name.
103  virtual const char *Demangle(const char *name) {
104    return name;
105  }
106  virtual void PrepareForSandboxing() {}
107
108  // Allow user to install hooks that would be called before/after Symbolizer
109  // does the actual file/line info fetching. Specific sanitizers may need this
110  // to distinguish system library calls made in user code from calls made
111  // during in-process symbolization.
112  typedef void (*StartSymbolizationHook)();
113  typedef void (*EndSymbolizationHook)();
114  // May be called at most once.
115  void AddHooks(StartSymbolizationHook start_hook,
116                EndSymbolizationHook end_hook);
117
118 private:
119  /// Platform-specific function for creating a Symbolizer object.
120  static Symbolizer *PlatformInit(const char *path_to_external);
121  /// Create a symbolizer and store it to symbolizer_ without checking if one
122  /// already exists.  Not thread safe.
123  static Symbolizer *CreateAndStore(const char *path_to_external);
124
125  static Symbolizer *symbolizer_;
126  static StaticSpinMutex init_mu_;
127
128 protected:
129  Symbolizer();
130
131  static LowLevelAllocator symbolizer_allocator_;
132
133  StartSymbolizationHook start_hook_;
134  EndSymbolizationHook end_hook_;
135  class SymbolizerScope {
136   public:
137    explicit SymbolizerScope(const Symbolizer *sym);
138    ~SymbolizerScope();
139   private:
140    const Symbolizer *sym_;
141  };
142};
143
144}  // namespace __sanitizer
145
146#endif  // SANITIZER_SYMBOLIZER_H
147