1//===- Errno.cpp - errno support --------------------------------*- 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 implements the errno wrappers.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/Errno.h"
15#include "llvm/Config/config.h"     // Get autoconf configuration settings
16#include "llvm/Support/raw_ostream.h"
17
18#if HAVE_STRING_H
19#include <string.h>
20
21#if HAVE_ERRNO_H
22#include <errno.h>
23#endif
24
25//===----------------------------------------------------------------------===//
26//=== WARNING: Implementation here must contain only TRULY operating system
27//===          independent code.
28//===----------------------------------------------------------------------===//
29
30namespace llvm {
31namespace sys {
32
33#if HAVE_ERRNO_H
34std::string StrError() {
35  return StrError(errno);
36}
37#endif  // HAVE_ERRNO_H
38
39std::string StrError(int errnum) {
40  const int MaxErrStrLen = 2000;
41  char buffer[MaxErrStrLen];
42  buffer[0] = '\0';
43  std::string str;
44#ifdef HAVE_STRERROR_R
45  // strerror_r is thread-safe.
46  if (errnum)
47# if defined(__GLIBC__) && defined(_GNU_SOURCE)
48    // glibc defines its own incompatible version of strerror_r
49    // which may not use the buffer supplied.
50    str = strerror_r(errnum,buffer,MaxErrStrLen-1);
51# else
52    strerror_r(errnum,buffer,MaxErrStrLen-1);
53    str = buffer;
54# endif
55#elif HAVE_DECL_STRERROR_S // "Windows Secure API"
56    if (errnum)
57      strerror_s(buffer, MaxErrStrLen - 1, errnum);
58#elif defined(HAVE_STRERROR)
59  // Copy the thread un-safe result of strerror into
60  // the buffer as fast as possible to minimize impact
61  // of collision of strerror in multiple threads.
62  if (errnum)
63    str = strerror(errnum);
64#else
65  // Strange that this system doesn't even have strerror
66  // but, oh well, just use a generic message
67  raw_string_ostream stream(str);
68  stream << "Error #" << errnum;
69  stream.flush();
70#endif
71  return str;
72}
73
74}  // namespace sys
75}  // namespace llvm
76
77#endif  // HAVE_STRING_H
78