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1//===-- sanitizer_symbolizer_internal.h -------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Header for internal classes and functions to be used by implementations of
10// symbolizers.
11//
12//===----------------------------------------------------------------------===//
13#ifndef SANITIZER_SYMBOLIZER_INTERNAL_H
14#define SANITIZER_SYMBOLIZER_INTERNAL_H
15
16#include "sanitizer_file.h"
17#include "sanitizer_symbolizer.h"
18#include "sanitizer_vector.h"
19
20namespace __sanitizer {
21
22// Parsing helpers, 'str' is searched for delimiter(s) and a string or uptr
23// is extracted. When extracting a string, a newly allocated (using
24// InternalAlloc) and null-terminated buffer is returned. They return a pointer
25// to the next characted after the found delimiter.
26const char *ExtractToken(const char *str, const char *delims, char **result);
27const char *ExtractInt(const char *str, const char *delims, int *result);
28const char *ExtractUptr(const char *str, const char *delims, uptr *result);
29const char *ExtractTokenUpToDelimiter(const char *str, const char *delimiter,
30 char **result);
31
32const char *DemangleSwiftAndCXX(const char *name);
33
34// SymbolizerTool is an interface that is implemented by individual "tools"
35// that can perform symbolication (external llvm-symbolizer, libbacktrace,
36// Windows DbgHelp symbolizer, etc.).
37class SymbolizerTool {
38 public:
39 // The main |Symbolizer| class implements a "fallback chain" of symbolizer
40 // tools. In a request to symbolize an address, if one tool returns false,
41 // the next tool in the chain will be tried.
42 SymbolizerTool *next;
43
44 SymbolizerTool() : next(nullptr) { }
45
46 // Can't declare pure virtual functions in sanitizer runtimes:
47 // __cxa_pure_virtual might be unavailable.
48
49 // The |stack| parameter is inout. It is pre-filled with the address,
50 // module base and module offset values and is to be used to construct
51 // other stack frames.
52 virtual bool SymbolizePC(uptr addr, SymbolizedStack *stack) {
53 UNIMPLEMENTED();
54 }
55
56 // The |info| parameter is inout. It is pre-filled with the module base
57 // and module offset values.
58 virtual bool SymbolizeData(uptr addr, DataInfo *info) {
59 UNIMPLEMENTED();
60 }
61
62 virtual bool SymbolizeFrame(uptr addr, FrameInfo *info) {
63 return false;
64 }
65
66 virtual void Flush() {}
67
68 // Return nullptr to fallback to the default platform-specific demangler.
69 virtual const char *Demangle(const char *name) {
70 return nullptr;
71 }
72
73 protected:
74 ~SymbolizerTool() {}
75};
76
77// SymbolizerProcess encapsulates communication between the tool and
78// external symbolizer program, running in a different subprocess.
79// SymbolizerProcess may not be used from two threads simultaneously.
80class SymbolizerProcess {
81 public:
82 explicit SymbolizerProcess(const char *path, bool use_posix_spawn = false);
83 const char *SendCommand(const char *command);
84
85 protected:
86 ~SymbolizerProcess() {}
87
88 /// The maximum number of arguments required to invoke a tool process.
89 static const unsigned kArgVMax = 16;
90
91 // Customizable by subclasses.
92 virtual bool StartSymbolizerSubprocess();
93 virtual bool ReadFromSymbolizer();
94 // Return the environment to run the symbolizer in.
95 virtual char **GetEnvP() { return GetEnviron(); }
96 InternalMmapVector<char> &GetBuff() { return buffer_; }
97
98 private:
99 virtual bool ReachedEndOfOutput(const char *buffer, uptr length) const {
100 UNIMPLEMENTED();
101 }
102
103 /// Fill in an argv array to invoke the child process.
104 virtual void GetArgV(const char *path_to_binary,
105 const char *(&argv)[kArgVMax]) const {
106 UNIMPLEMENTED();
107 }
108
109 bool Restart();
110 const char *SendCommandImpl(const char *command);
111 bool WriteToSymbolizer(const char *buffer, uptr length);
112
113 const char *path_;
114 fd_t input_fd_;
115 fd_t output_fd_;
116
117 InternalMmapVector<char> buffer_;
118
119 static const uptr kMaxTimesRestarted = 5;
120 static const int kSymbolizerStartupTimeMillis = 10;
121 uptr times_restarted_;
122 bool failed_to_start_;
123 bool reported_invalid_path_;
124 bool use_posix_spawn_;
125};
126
127class LLVMSymbolizerProcess;
128
129// This tool invokes llvm-symbolizer in a subprocess. It should be as portable
130// as the llvm-symbolizer tool is.
131class LLVMSymbolizer final : public SymbolizerTool {
132 public:
133 explicit LLVMSymbolizer(const char *path, LowLevelAllocator *allocator);
134
135 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override;
136 bool SymbolizeData(uptr addr, DataInfo *info) override;
137 bool SymbolizeFrame(uptr addr, FrameInfo *info) override;
138
139 private:
140 const char *FormatAndSendCommand(const char *command_prefix,
141 const char *module_name, uptr module_offset,
142 ModuleArch arch);
143
144 LLVMSymbolizerProcess *symbolizer_process_;
145 static const uptr kBufferSize = 16 * 1024;
146 char buffer_[kBufferSize];
147};
148
149// Parses one or more two-line strings in the following format:
150// <function_name>
151// <file_name>:<line_number>[:<column_number>]
152// Used by LLVMSymbolizer, Addr2LinePool and InternalSymbolizer, since all of
153// them use the same output format. Returns true if any useful debug
154// information was found.
155void ParseSymbolizePCOutput(const char *str, SymbolizedStack *res);
156
157// Parses a two-line string in the following format:
158// <symbol_name>
159// <start_address> <size>
160// Used by LLVMSymbolizer and InternalSymbolizer.
161void ParseSymbolizeDataOutput(const char *str, DataInfo *info);
162
163// Parses repeated strings in the following format:
164// <function_name>
165// <var_name>
166// <file_name>:<line_number>[:<column_number>]
167// [<frame_offset>|??] [<size>|??] [<tag_offset>|??]
168// Used by LLVMSymbolizer and InternalSymbolizer.
169void ParseSymbolizeFrameOutput(const char *str,
170 InternalMmapVector<LocalInfo> *locals);
171
172} // namespace __sanitizer
173
174#endif // SANITIZER_SYMBOLIZER_INTERNAL_H