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