lib/Support/ErrorHandling.cpp

   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/ADT/Twine.h"
  16 #include "llvm/Support/Debug.h"
  17 #include "llvm/Support/ErrorHandling.h"
  18 #include "llvm/Support/raw_ostream.h"
  19 #include "llvm/Support/Signals.h"
  20 #include "llvm/Support/Threading.h"
  21 #include "llvm/ADT/SmallVector.h"
  22 #include "llvm/Config/config.h"
  23 #include <cassert>
  24 #include <cstdlib>
  25
  26 #if defined(HAVE_UNISTD_H)
  27 # include <unistd.h>
  28 #endif
  29 #if defined(_MSC_VER)
  30 # include <io.h>
  31 # include <fcntl.h>
  32 #endif
  33
  34 using namespace llvm;
  35
  36 static fatal_error_handler_t ErrorHandler = 0;
  37 static void *ErrorHandlerUserData = 0;
  38
  39 void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
  40                                        void *user_data) {
  41   assert(!llvm_is_multithreaded() &&
  42          "Cannot register error handlers after starting multithreaded mode!\n");
  43   assert(!ErrorHandler && "Error handler already registered!\n");
  44   ErrorHandler = handler;
  45   ErrorHandlerUserData = user_data;
  46 }
  47
  48 void llvm::remove_fatal_error_handler() {
  49   ErrorHandler = 0;
  50 }
  51
  52 void llvm::report_fatal_error(const char *Reason) {
  53   report_fatal_error(Twine(Reason));
  54 }
  55
  56 void llvm::report_fatal_error(const std::string &Reason) {
  57   report_fatal_error(Twine(Reason));
  58 }
  59
  60 void llvm::report_fatal_error(StringRef Reason) {
  61   report_fatal_error(Twine(Reason));
  62 }
  63
  64 void llvm::report_fatal_error(const Twine &Reason) {
  65   if (ErrorHandler) {
  66     ErrorHandler(ErrorHandlerUserData, Reason.str());
  67   } else {
  68     // Blast the result out to stderr.  We don't try hard to make sure this
  69     // succeeds (e.g. handling EINTR) and we can't use errs() here because
  70     // raw ostreams can call report_fatal_error.
  71     SmallVector<char, 64> Buffer;
  72     raw_svector_ostream OS(Buffer);
  73     OS << "LLVM ERROR: " << Reason << "\n";
  74     StringRef MessageStr = OS.str();
  75     ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
  76     (void)written; // If something went wrong, we deliberately just give up.
  77   }
  78
  79   // If we reached here, we are failing ungracefully. Run the interrupt handlers
  80   // to make sure any special cleanups get done, in particular that we remove
  81   // files registered with RemoveFileOnSignal.
  82   sys::RunInterruptHandlers();
  83
  84   exit(1);
  85 }
  86
  87 void llvm::llvm_unreachable_internal(const char *msg, const char *file,
  88                                      unsigned line) {
  89   // This code intentionally doesn't call the ErrorHandler callback, because
  90   // llvm_unreachable is intended to be used to indicate "impossible"
  91   // situations, and not legitimate runtime errors.
  92   if (msg)
  93     dbgs() << msg << "\n";
  94   dbgs() << "UNREACHABLE executed";
  95   if (file)
  96     dbgs() << " at " << file << ":" << line;
  97   dbgs() << "!\n";
  98   abort();
  99 }