1 //===- llvm/Support/Signals.h - Signal Handling support ----------*- 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 // This file defines some helpful functions for dealing with the possibility of 10 // unix signals occurring while your program is running. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_SIGNALS_H 15 #define LLVM_SUPPORT_SIGNALS_H 16 17 #include <string> 18 19 namespace llvm { 20 class StringRef; 21 class raw_ostream; 22 23 namespace sys { 24 25 /// This function runs all the registered interrupt handlers, including the 26 /// removal of files registered by RemoveFileOnSignal. 27 void RunInterruptHandlers(); 28 29 /// This function registers signal handlers to ensure that if a signal gets 30 /// delivered that the named file is removed. 31 /// Remove a file if a fatal signal occurs. 32 bool RemoveFileOnSignal(StringRef Filename, std::string* ErrMsg = nullptr); 33 34 /// This function removes a file from the list of files to be removed on 35 /// signal delivery. 36 void DontRemoveFileOnSignal(StringRef Filename); 37 38 /// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the 39 /// process, print a stack trace and then exit. 40 /// Print a stack trace if a fatal signal occurs. 41 /// \param Argv0 the current binary name, used to find the symbolizer 42 /// relative to the current binary before searching $PATH; can be 43 /// StringRef(), in which case we will only search $PATH. 44 /// \param DisableCrashReporting if \c true, disable the normal crash 45 /// reporting mechanisms on the underlying operating system. 46 void PrintStackTraceOnErrorSignal(StringRef Argv0, 47 bool DisableCrashReporting = false); 48 49 /// Disable all system dialog boxes that appear when the process crashes. 50 void DisableSystemDialogsOnCrash(); 51 52 /// Print the stack trace using the given \c raw_ostream object. 53 void PrintStackTrace(raw_ostream &OS); 54 55 // Run all registered signal handlers. 56 void RunSignalHandlers(); 57 58 using SignalHandlerCallback = void (*)(void *); 59 60 /// Add a function to be called when an abort/kill signal is delivered to the 61 /// process. The handler can have a cookie passed to it to identify what 62 /// instance of the handler it is. 63 void AddSignalHandler(SignalHandlerCallback FnPtr, void *Cookie); 64 65 /// This function registers a function to be called when the user "interrupts" 66 /// the program (typically by pressing ctrl-c). When the user interrupts the 67 /// program, the specified interrupt function is called instead of the program 68 /// being killed, and the interrupt function automatically disabled. 69 /// 70 /// Note that interrupt functions are not allowed to call any non-reentrant 71 /// functions. An null interrupt function pointer disables the current 72 /// installed function. Note also that the handler may be executed on a 73 /// different thread on some platforms. 74 void SetInterruptFunction(void (*IF)()); 75 76 /// Registers a function to be called when an "info" signal is delivered to 77 /// the process. 78 /// 79 /// On POSIX systems, this will be SIGUSR1; on systems that have it, SIGINFO 80 /// will also be used (typically ctrl-t). 81 /// 82 /// Note that signal handlers are not allowed to call any non-reentrant 83 /// functions. An null function pointer disables the current installed 84 /// function. Note also that the handler may be executed on a different 85 /// thread on some platforms. 86 void SetInfoSignalFunction(void (*Handler)()); 87 88 /// Registers a function to be called in a "one-shot" manner when a pipe 89 /// signal is delivered to the process (i.e., on a failed write to a pipe). 90 /// After the pipe signal is handled once, the handler is unregistered. 91 /// 92 /// The LLVM signal handling code will not install any handler for the pipe 93 /// signal unless one is provided with this API (see \ref 94 /// DefaultOneShotPipeSignalHandler). This handler must be provided before 95 /// any other LLVM signal handlers are installed: the \ref InitLLVM 96 /// constructor has a flag that can simplify this setup. 97 /// 98 /// Note that the handler is not allowed to call any non-reentrant 99 /// functions. A null handler pointer disables the current installed 100 /// function. Note also that the handler may be executed on a 101 /// different thread on some platforms. 102 /// 103 /// This is a no-op on Windows. 104 void SetOneShotPipeSignalFunction(void (*Handler)()); 105 106 /// On Unix systems, this function exits with an "IO error" exit code. 107 /// This is a no-op on Windows. 108 void DefaultOneShotPipeSignalHandler(); 109 110 /// This function does the following: 111 /// - clean up any temporary files registered with RemoveFileOnSignal() 112 /// - dump the callstack from the exception context 113 /// - call any relevant interrupt/signal handlers 114 /// - create a core/mini dump of the exception context whenever possible 115 /// Context is a system-specific failure context: it is the signal type on 116 /// Unix; the ExceptionContext on Windows. 117 void CleanupOnSignal(uintptr_t Context); 118 } // End sys namespace 119 } // End llvm namespace 120 121 #endif 122