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 33 std::string StrError() { 34 return StrError(errno); 35 } 36 #endif // HAVE_ERRNO_H 37 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
