libsanitizer/sanitizer_common/sanitizer_symbolizer_internal.h

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