1//===-- sanitizer_symbolizer_internal.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// Header for internal classes and functions to be used by implementations of
11// symbolizers.
12//
13//===----------------------------------------------------------------------===//
14#ifndef SANITIZER_SYMBOLIZER_INTERNAL_H
15#define SANITIZER_SYMBOLIZER_INTERNAL_H
16
17#include "sanitizer_symbolizer.h"
18
19namespace __sanitizer {
20
21// Parsing helpers, 'str' is searched for delimiter(s) and a string or uptr
22// is extracted. When extracting a string, a newly allocated (using
23// InternalAlloc) and null-terminataed buffer is returned. They return a pointer
24// to the next characted after the found delimiter.
25const char *ExtractToken(const char *str, const char *delims, char **result);
26const char *ExtractInt(const char *str, const char *delims, int *result);
27const char *ExtractUptr(const char *str, const char *delims, uptr *result);
28const char *ExtractTokenUpToDelimiter(const char *str, const char *delimiter,
29                                      char **result);
30
31const char *DemangleCXXABI(const char *name);
32
33// SymbolizerTool is an interface that is implemented by individual "tools"
34// that can perform symbolication (external llvm-symbolizer, libbacktrace,
35// Windows DbgHelp symbolizer, etc.).
36class SymbolizerTool {
37 public:
38  // The main |Symbolizer| class implements a "fallback chain" of symbolizer
39  // tools. In a request to symbolize an address, if one tool returns false,
40  // the next tool in the chain will be tried.
41  SymbolizerTool *next;
42
43  SymbolizerTool() : next(nullptr) { }
44
45  // Can't declare pure virtual functions in sanitizer runtimes:
46  // __cxa_pure_virtual might be unavailable.
47
48  // The |stack| parameter is inout. It is pre-filled with the address,
49  // module base and module offset values and is to be used to construct
50  // other stack frames.
51  virtual bool SymbolizePC(uptr addr, SymbolizedStack *stack) {
52    UNIMPLEMENTED();
53  }
54
55  // The |info| parameter is inout. It is pre-filled with the module base
56  // and module offset values.
57  virtual bool SymbolizeData(uptr addr, DataInfo *info) {
58    UNIMPLEMENTED();
59  }
60
61  virtual void Flush() {}
62
63  // Return nullptr to fallback to the default platform-specific demangler.
64  virtual const char *Demangle(const char *name) {
65    return nullptr;
66  }
67};
68
69// SymbolizerProcess encapsulates communication between the tool and
70// external symbolizer program, running in a different subprocess.
71// SymbolizerProcess may not be used from two threads simultaneously.
72class SymbolizerProcess {
73 public:
74  explicit SymbolizerProcess(const char *path, bool use_forkpty = false);
75  const char *SendCommand(const char *command);
76
77 protected:
78  virtual bool ReachedEndOfOutput(const char *buffer, uptr length) const {
79    UNIMPLEMENTED();
80  }
81
82  /// The maximum number of arguments required to invoke a tool process.
83  enum { kArgVMax = 6 };
84
85  /// Fill in an argv array to invoke the child process.
86  virtual void GetArgV(const char *path_to_binary,
87                       const char *(&argv)[kArgVMax]) const {
88    UNIMPLEMENTED();
89  }
90
91  virtual bool ReadFromSymbolizer(char *buffer, uptr max_length);
92
93 private:
94  bool Restart();
95  const char *SendCommandImpl(const char *command);
96  bool WriteToSymbolizer(const char *buffer, uptr length);
97  bool StartSymbolizerSubprocess();
98
99  const char *path_;
100  fd_t input_fd_;
101  fd_t output_fd_;
102
103  static const uptr kBufferSize = 16 * 1024;
104  char buffer_[kBufferSize];
105
106  static const uptr kMaxTimesRestarted = 5;
107  static const int kSymbolizerStartupTimeMillis = 10;
108  uptr times_restarted_;
109  bool failed_to_start_;
110  bool reported_invalid_path_;
111  bool use_forkpty_;
112};
113
114class LLVMSymbolizerProcess;
115
116// This tool invokes llvm-symbolizer in a subprocess. It should be as portable
117// as the llvm-symbolizer tool is.
118class LLVMSymbolizer : public SymbolizerTool {
119 public:
120  explicit LLVMSymbolizer(const char *path, LowLevelAllocator *allocator);
121
122  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override;
123
124  bool SymbolizeData(uptr addr, DataInfo *info) override;
125
126 private:
127  const char *SendCommand(bool is_data, const char *module_name,
128                          uptr module_offset);
129
130  LLVMSymbolizerProcess *symbolizer_process_;
131  static const uptr kBufferSize = 16 * 1024;
132  char buffer_[kBufferSize];
133};
134
135// Parses one or more two-line strings in the following format:
136//   <function_name>
137//   <file_name>:<line_number>[:<column_number>]
138// Used by LLVMSymbolizer, Addr2LinePool and InternalSymbolizer, since all of
139// them use the same output format.  Returns true if any useful debug
140// information was found.
141void ParseSymbolizePCOutput(const char *str, SymbolizedStack *res);
142
143// Parses a two-line string in the following format:
144//   <symbol_name>
145//   <start_address> <size>
146// Used by LLVMSymbolizer and InternalSymbolizer.
147void ParseSymbolizeDataOutput(const char *str, DataInfo *info);
148
149}  // namespace __sanitizer
150
151#endif  // SANITIZER_SYMBOLIZER_INTERNAL_H
152