1 //===- llvm/Support/Signals.h - Signal Handling support ----------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines some helpful functions for dealing with the possibility of
10 // unix signals occurring while your program is running.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_SIGNALS_H
15 #define LLVM_SUPPORT_SIGNALS_H
25 /// This function runs all the registered interrupt handlers, including the
26 /// removal of files registered by RemoveFileOnSignal.
27 void RunInterruptHandlers();
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);
34 /// This function removes a file from the list of files to be removed on
36 void DontRemoveFileOnSignal(StringRef Filename);
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);
49 /// Disable all system dialog boxes that appear when the process crashes.
50 void DisableSystemDialogsOnCrash();
52 /// Print the stack trace using the given \c raw_ostream object.
53 void PrintStackTrace(raw_ostream &OS);
55 // Run all registered signal handlers.
56 void RunSignalHandlers();
58 using SignalHandlerCallback = void (*)(void *);
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);
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.
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)());
76 /// Registers a function to be called when an "info" signal is delivered to
79 /// On POSIX systems, this will be SIGUSR1; on systems that have it, SIGINFO
80 /// will also be used (typically ctrl-t).
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)());
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.
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.
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.
103 /// This is a no-op on Windows.
104 void SetOneShotPipeSignalFunction(void (*Handler)());
106 /// On Unix systems, this function exits with an "IO error" exit code.
107 /// This is a no-op on Windows.
108 void DefaultOneShotPipeSignalHandler();
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