1 //===- llvm/Support/PrettyStackTrace.h - Pretty Crash Handling --*- 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 // This file defines the PrettyStackTraceEntry class, which is used to make 11 // crashes give more contextual information about what the program was doing 12 // when it crashed. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_SUPPORT_PRETTYSTACKTRACE_H 17 #define LLVM_SUPPORT_PRETTYSTACKTRACE_H 18 19 #include "llvm/Support/Compiler.h" 20 21 namespace llvm { 22 class raw_ostream; 23 24 void EnablePrettyStackTrace(); 25 26 /// PrettyStackTraceEntry - This class is used to represent a frame of the 27 /// "pretty" stack trace that is dumped when a program crashes. You can define 28 /// subclasses of this and declare them on the program stack: when they are 29 /// constructed and destructed, they will add their symbolic frames to a 30 /// virtual stack trace. This gets dumped out if the program crashes. 31 class PrettyStackTraceEntry { 32 friend PrettyStackTraceEntry *ReverseStackTrace(PrettyStackTraceEntry *); 33 34 PrettyStackTraceEntry *NextEntry; 35 PrettyStackTraceEntry(const PrettyStackTraceEntry &) = delete; 36 void operator=(const PrettyStackTraceEntry &) = delete; 37 public: 38 PrettyStackTraceEntry(); 39 virtual ~PrettyStackTraceEntry(); 40 41 /// print - Emit information about this stack frame to OS. 42 virtual void print(raw_ostream &OS) const = 0; 43 44 /// getNextEntry - Return the next entry in the list of frames. getNextEntry()45 const PrettyStackTraceEntry *getNextEntry() const { return NextEntry; } 46 }; 47 48 /// PrettyStackTraceString - This object prints a specified string (which 49 /// should not contain newlines) to the stream as the stack trace when a crash 50 /// occurs. 51 class PrettyStackTraceString : public PrettyStackTraceEntry { 52 const char *Str; 53 public: PrettyStackTraceString(const char * str)54 PrettyStackTraceString(const char *str) : Str(str) {} 55 void print(raw_ostream &OS) const override; 56 }; 57 58 /// PrettyStackTraceProgram - This object prints a specified program arguments 59 /// to the stream as the stack trace when a crash occurs. 60 class PrettyStackTraceProgram : public PrettyStackTraceEntry { 61 int ArgC; 62 const char *const *ArgV; 63 public: PrettyStackTraceProgram(int argc,const char * const * argv)64 PrettyStackTraceProgram(int argc, const char * const*argv) 65 : ArgC(argc), ArgV(argv) { 66 EnablePrettyStackTrace(); 67 } 68 void print(raw_ostream &OS) const override; 69 }; 70 71 /// Returns the topmost element of the "pretty" stack state. 72 const void *SavePrettyStackState(); 73 74 /// Restores the topmost element of the "pretty" stack state to State, which 75 /// should come from a previous call to SavePrettyStackState(). This is 76 /// useful when using a CrashRecoveryContext in code that also uses 77 /// PrettyStackTraceEntries, to make sure the stack that's printed if a crash 78 /// happens after a crash that's been recovered by CrashRecoveryContext 79 /// doesn't have frames on it that were added in code unwound by the 80 /// CrashRecoveryContext. 81 void RestorePrettyStackState(const void *State); 82 83 } // end namespace llvm 84 85 #endif 86