llvm/lib/Support/Errno.cpp

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//===- 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"
#if HAVE_STRING_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
#endif // HAVE_STRING_H