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