LLVM  4.0.0
Support/ErrorHandling.h
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1 //===- llvm/Support/ErrorHandling.h - Fatal error 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 an API used to indicate fatal error conditions. Non-fatal
11 // errors (most of them) should be handled through LLVMContext.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_SUPPORT_ERRORHANDLING_H
16 #define LLVM_SUPPORT_ERRORHANDLING_H
17 
18 #include "llvm/Support/Compiler.h"
19 #include <string>
20 
21 namespace llvm {
22 class StringRef;
23  class Twine;
24 
25  /// An error handler callback.
26  typedef void (*fatal_error_handler_t)(void *user_data,
27  const std::string& reason,
28  bool gen_crash_diag);
29 
30  /// install_fatal_error_handler - Installs a new error handler to be used
31  /// whenever a serious (non-recoverable) error is encountered by LLVM.
32  ///
33  /// If no error handler is installed the default is to print the error message
34  /// to stderr, and call exit(1). If an error handler is installed then it is
35  /// the handler's responsibility to log the message, it will no longer be
36  /// printed to stderr. If the error handler returns, then exit(1) will be
37  /// called.
38  ///
39  /// It is dangerous to naively use an error handler which throws an exception.
40  /// Even though some applications desire to gracefully recover from arbitrary
41  /// faults, blindly throwing exceptions through unfamiliar code isn't a way to
42  /// achieve this.
43  ///
44  /// \param user_data - An argument which will be passed to the install error
45  /// handler.
47  void *user_data = nullptr);
48 
49  /// Restores default error handling behaviour.
51 
52  /// ScopedFatalErrorHandler - This is a simple helper class which just
53  /// calls install_fatal_error_handler in its constructor and
54  /// remove_fatal_error_handler in its destructor.
57  void *user_data = nullptr) {
58  install_fatal_error_handler(handler, user_data);
59  }
60 
62  };
63 
64 /// Reports a serious error, calling any installed error handler. These
65 /// functions are intended to be used for error conditions which are outside
66 /// the control of the compiler (I/O errors, invalid user input, etc.)
67 ///
68 /// If no error handler is installed the default is to print the message to
69 /// standard error, followed by a newline.
70 /// After the error handler is called this function will call exit(1), it
71 /// does not return.
72 LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason,
73  bool gen_crash_diag = true);
74 LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason,
75  bool gen_crash_diag = true);
76 LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason,
77  bool gen_crash_diag = true);
78 LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason,
79  bool gen_crash_diag = true);
80 
81  /// This function calls abort(), and prints the optional message to stderr.
82  /// Use the llvm_unreachable macro (that adds location info), instead of
83  /// calling this function directly.
85  llvm_unreachable_internal(const char *msg=nullptr, const char *file=nullptr,
86  unsigned line=0);
87 }
88 
89 /// Marks that the current location is not supposed to be reachable.
90 /// In !NDEBUG builds, prints the message and location info to stderr.
91 /// In NDEBUG builds, becomes an optimizer hint that the current location
92 /// is not supposed to be reachable. On compilers that don't support
93 /// such hints, prints a reduced message instead.
94 ///
95 /// Use this instead of assert(0). It conveys intent more clearly and
96 /// allows compilers to omit some unnecessary code.
97 #ifndef NDEBUG
98 #define llvm_unreachable(msg) \
99  ::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
100 #elif defined(LLVM_BUILTIN_UNREACHABLE)
101 #define llvm_unreachable(msg) LLVM_BUILTIN_UNREACHABLE
102 #else
103 #define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal()
104 #endif
105 
106 #endif
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
void(* fatal_error_handler_t)(void *user_data, const std::string &reason, bool gen_crash_diag)
An error handler callback.
void remove_fatal_error_handler()
Restores default error handling behaviour.
dot regions Print regions of function to dot file(with no function bodies)"
#define LLVM_ATTRIBUTE_NORETURN
Definition: Compiler.h:212
LLVM_ATTRIBUTE_NORETURN void llvm_unreachable_internal(const char *msg=nullptr, const char *file=nullptr, unsigned line=0)
This function calls abort(), and prints the optional message to stderr.
ScopedFatalErrorHandler - This is a simple helper class which just calls install_fatal_error_handler ...
ScopedFatalErrorHandler(fatal_error_handler_t handler, void *user_data=nullptr)
void install_fatal_error_handler(fatal_error_handler_t handler, void *user_data=nullptr)
install_fatal_error_handler - Installs a new error handler to be used whenever a serious (non-recover...