llvm/lib/Support/Errno.cpp
Reid Kleckner 65985348c5 Remove dead or useless header checks from cmake and autoconf
On Windows, this improves clean cmake configuration time on my
workstation from 1m58s to 1m32s, which is pretty significant.  There's
probably more that can be done here, but this is the low hanging fruit.

Eric volunteered to regenerate ./configure for me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187209 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-26 16:54:23 +00:00

76 lines
2.2 KiB
C++

//===- Errno.cpp - errno support --------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the errno wrappers.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Errno.h"
#include "llvm/Config/config.h" // Get autoconf configuration settings
#include "llvm/Support/raw_ostream.h"
#include <string.h>
#if HAVE_ERRNO_H
#include <errno.h>
#endif
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//=== independent code.
//===----------------------------------------------------------------------===//
namespace llvm {
namespace sys {
#if HAVE_ERRNO_H
std::string StrError() {
return StrError(errno);
}
#endif // HAVE_ERRNO_H
std::string StrError(int errnum) {
const int MaxErrStrLen = 2000;
char buffer[MaxErrStrLen];
buffer[0] = '\0';
std::string str;
#ifdef HAVE_STRERROR_R
// strerror_r is thread-safe.
if (errnum)
# if defined(__GLIBC__) && defined(_GNU_SOURCE)
// glibc defines its own incompatible version of strerror_r
// which may not use the buffer supplied.
str = strerror_r(errnum,buffer,MaxErrStrLen-1);
# else
strerror_r(errnum,buffer,MaxErrStrLen-1);
str = buffer;
# endif
#elif HAVE_DECL_STRERROR_S // "Windows Secure API"
if (errnum) {
strerror_s(buffer, MaxErrStrLen - 1, errnum);
str = buffer;
}
#elif defined(HAVE_STRERROR)
// Copy the thread un-safe result of strerror into
// the buffer as fast as possible to minimize impact
// of collision of strerror in multiple threads.
if (errnum)
str = strerror(errnum);
#else
// Strange that this system doesn't even have strerror
// but, oh well, just use a generic message
raw_string_ostream stream(str);
stream << "Error #" << errnum;
stream.flush();
#endif
return str;
}
} // namespace sys
} // namespace llvm