LLVM  15.0.0git
Errno.cpp
Go to the documentation of this file.
1 //===- Errno.cpp - errno support --------------------------------*- C++ -*-===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the errno wrappers.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Support/Errno.h"
14 #include "llvm/Config/config.h"
15 #include <cstring>
16 
17 #if HAVE_ERRNO_H
18 #include <errno.h>
19 #endif
20 
21 //===----------------------------------------------------------------------===//
22 //=== WARNING: Implementation here must contain only TRULY operating system
23 //=== independent code.
24 //===----------------------------------------------------------------------===//
25 
26 namespace llvm {
27 namespace sys {
28 
29 #if HAVE_ERRNO_H
30 std::string StrError() {
31  return StrError(errno);
32 }
33 #endif // HAVE_ERRNO_H
34 
35 std::string StrError(int errnum) {
36  std::string str;
37  if (errnum == 0)
38  return str;
39 #if defined(HAVE_STRERROR_R) || HAVE_DECL_STRERROR_S
40  const int MaxErrStrLen = 2000;
41  char buffer[MaxErrStrLen];
42  buffer[0] = '\0';
43 #endif
44 
45 #ifdef HAVE_STRERROR_R
46  // strerror_r is thread-safe.
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  strerror_s(buffer, MaxErrStrLen - 1, errnum);
57  str = buffer;
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  str = strerror(errnum);
63 #else
64  // Strange that this system doesn't even have strerror
65  // but, oh well, just use a generic message
66  raw_string_ostream stream(str);
67  stream << "Error #" << errnum;
68  stream.flush();
69 #endif
70  return str;
71 }
72 
73 } // namespace sys
74 } // namespace llvm
llvm::sys::StrError
std::string StrError()
Returns a string representation of the errno value, using whatever thread-safe variant of strerror() ...
Definition: Errno.cpp:30
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:17
llvm::raw_string_ostream
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:632
llvm::raw_ostream::flush
void flush()
Definition: raw_ostream.h:187
Errno.h