Add a portable strerror*() wrapper, llvm::sys::StrError(). This includes the
Windows variant, strerror_s, but I couldn't test that.
I'll update configure and config.h.in in a subsequent patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74621 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Errno.cpp b/lib/System/Errno.cpp
new file mode 100644
index 0000000..f4e3a88
--- /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