ErrorHandling.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===- lib/Support/ErrorHandling.cpp - Callbacks for errors ---------------===//
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#include "llvm/Support/ErrorHandling.h"
16#include "llvm-c/Core.h"
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/Twine.h"
19#include "llvm/Config/config.h"
20#include "llvm/Support/Debug.h"
21#include "llvm/Support/Signals.h"
22#include "llvm/Support/Threading.h"
23#include "llvm/Support/raw_ostream.h"
24#include <cassert>
25#include <cstdlib>
26
27#if defined(HAVE_UNISTD_H)
28# include <unistd.h>
29#endif
30#if defined(_MSC_VER)
31# include <io.h>
32# include <fcntl.h>
33#endif
34
35using namespace llvm;
36
37static fatal_error_handler_t ErrorHandler = nullptr;
38static void *ErrorHandlerUserData = nullptr;
39
40void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
41                                       void *user_data) {
42  assert(!llvm_is_multithreaded() &&
43         "Cannot register error handlers after starting multithreaded mode!\n");
44  assert(!ErrorHandler && "Error handler already registered!\n");
45  ErrorHandler = handler;
46  ErrorHandlerUserData = user_data;
47}
48
49void llvm::remove_fatal_error_handler() {
50  ErrorHandler = nullptr;
51}
52
53void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) {
54  report_fatal_error(Twine(Reason), GenCrashDiag);
55}
56
57void llvm::report_fatal_error(const std::string &Reason, bool GenCrashDiag) {
58  report_fatal_error(Twine(Reason), GenCrashDiag);
59}
60
61void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) {
62  report_fatal_error(Twine(Reason), GenCrashDiag);
63}
64
65void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
66  if (ErrorHandler) {
67    ErrorHandler(ErrorHandlerUserData, Reason.str(), GenCrashDiag);
68  } else {
69    // Blast the result out to stderr.  We don't try hard to make sure this
70    // succeeds (e.g. handling EINTR) and we can't use errs() here because
71    // raw ostreams can call report_fatal_error.
72    SmallVector<char, 64> Buffer;
73    raw_svector_ostream OS(Buffer);
74    OS << "LLVM ERROR: " << Reason << "\n";
75    StringRef MessageStr = OS.str();
76    ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
77    (void)written; // If something went wrong, we deliberately just give up.
78  }
79
80  // If we reached here, we are failing ungracefully. Run the interrupt handlers
81  // to make sure any special cleanups get done, in particular that we remove
82  // files registered with RemoveFileOnSignal.
83  sys::RunInterruptHandlers();
84
85  exit(1);
86}
87
88void llvm::llvm_unreachable_internal(const char *msg, const char *file,
89                                     unsigned line) {
90  // This code intentionally doesn't call the ErrorHandler callback, because
91  // llvm_unreachable is intended to be used to indicate "impossible"
92  // situations, and not legitimate runtime errors.
93  if (msg)
94    dbgs() << msg << "\n";
95  dbgs() << "UNREACHABLE executed";
96  if (file)
97    dbgs() << " at " << file << ":" << line;
98  dbgs() << "!\n";
99  abort();
100#ifdef LLVM_BUILTIN_UNREACHABLE
101  // Windows systems and possibly others don't declare abort() to be noreturn,
102  // so use the unreachable builtin to avoid a Clang self-host warning.
103  LLVM_BUILTIN_UNREACHABLE;
104#endif
105}
106
107static void bindingsErrorHandler(void *user_data, const std::string& reason,
108                                 bool gen_crash_diag) {
109  LLVMFatalErrorHandler handler =
110      LLVM_EXTENSION reinterpret_cast<LLVMFatalErrorHandler>(user_data);
111  handler(reason.c_str());
112}
113
114void LLVMInstallFatalErrorHandler(LLVMFatalErrorHandler Handler) {
115  install_fatal_error_handler(bindingsErrorHandler,
116                              LLVM_EXTENSION reinterpret_cast<void *>(Handler));
117}
118
119void LLVMResetFatalErrorHandler() {
120  remove_fatal_error_handler();
121}
122