3 files changed, 74 insertions, 26 deletions
diff --git a/lib/System/CMakeLists.txt b/lib/System/CMakeLists.txt
index 431629a14d..bf7a0c601e 100644
--- a/lib/System/CMakeLists.txt
+++ b/lib/System/CMakeLists.txt
@@ -3,6 +3,7 @@ add_llvm_library(LLVMSystem
   Atomic.cpp
   Disassembler.cpp
   DynamicLibrary.cpp
+  Errno.cpp
   Host.cpp
   IncludeFile.cpp
   Memory.cpp
diff --git a/lib/System/Errno.cpp b/lib/System/Errno.cpp
new file mode 100644
index 0000000000..f4e3a88d05
--- /dev/null
+++ b/lib/System/Errno.cpp
@@ -0,0 +1,71 @@
+//===- 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/System/Errno.h"
+#include "llvm/Config/config.h"     // Get autoconf configuration settings
+
+#if HAVE_STRING_H
+#include <string.h>
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//===          independent code.
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+namespace sys {
+
+#if HAVE_ERRNO_H
+#include <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';
+  char* str = buffer;
+#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);
+# endif
+#elif HAVE_STRERROR_S  // Windows.
+    if (errnum)
+      strerror_s(buffer, errnum);
+#elif 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)
+    strncpy(buffer,strerror(errnum),MaxErrStrLen-1);
+  buffer[MaxErrStrLen-1] = '\0';
+#else
+  // Strange that this system doesn't even have strerror
+  // but, oh well, just use a generic message
+  sprintf(buffer, "Error #%d", errnum);
+#endif
+  return str;
+}
+
+}  // namespace sys
+}  // namespace llvm
+
+#endif  // HAVE_STRING_H
diff --git a/lib/System/Unix/Unix.h b/lib/System/Unix/Unix.h
index c2c06dd114..c15866f3d9 100644
--- a/lib/System/Unix/Unix.h
+++ b/lib/System/Unix/Unix.h
@@ -20,6 +20,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Config/config.h"     // Get autoconf configuration settings
+#include "llvm/System/Errno.h"
 #include <cstdlib>
 #include <cstdio>
 #include <cstring>
@@ -77,34 +78,9 @@ static inline bool MakeErrMsg(
   std::string* ErrMsg, const std::string& prefix, int errnum = -1) {
   if (!ErrMsg)
     return true;
-  char buffer[MAXPATHLEN];
-  buffer[0] = 0;
-  char* str = buffer;
   if (errnum == -1)
     errnum = errno;
-#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,MAXPATHLEN-1);
-# else
-    strerror_r(errnum,buffer,MAXPATHLEN-1);
-# endif
-#elif 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)
-    strncpy(buffer,strerror(errnum),MAXPATHLEN-1);
-  buffer[MAXPATHLEN-1] = 0;
-#else
-  // Strange that this system doesn't even have strerror
-  // but, oh well, just use a generic message
-  sprintf(buffer, "Error #%d", errnum);
-#endif
-  *ErrMsg = prefix + ": " + str;
+  *ErrMsg = prefix + ": " + llvm::sys::StrError(errnum);
   return true;
 }