Newlib names ELAST differently than linux

[danalbert]

It would probably make sense to add the following block to include/__config and clean up all the duplication.

#ifndef ELAST
#if defined(__linux__)
#define ELAST 4095
#elif defined(_NEWLIB_VERSION) && defined(__ELASTERROR)
#define ELAST __ELASTERROR
#endif
#endif

[jroelofs]

That sounds like a good idea. Maybe it's better to have it be:

#if defined(ELAST)
#define LIBCPP_ELAST ELAST
#elif defined(__linux__)
#define LIBCPP_ELAST 4095
#elif defined(_NEWLIB_VERSION) && defined(__ELASTERROR)
#define LIBCPP_ELAST __ELASTERROR
#else
// Error here so that the person doing the libcxx port has an easier time:
#error This platform's ELAST hasn't been ported yet
#endif
#endif

... as I don't think it's appropriate for __config to be defining ELAST so globally.

[danalbert]

Yes, that would be better.

[jroelofs]

Address @danalbert's suggestion to move the configuration-ey stuff to include/__config

[danalbert]

src/ios.cpp

56

Could also define _LIBCPP_ELAST to a large dummy value that would make the second half of the conditional always true and get rid of all the pesky ifdefs. Up to you. I'm happy with the patch now.

[jroelofs]

r216943

include/__config

 #if defined(__APPLE__) || defined(__FreeBSD__)
 #define _LIBCPP_HAS_DEFAULTRUNELOCALE
 #endif
 
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__sun__)
 #define _LIBCPP_WCTYPE_IS_MASK
 #endif
 
+#if defined(ELAST)
+#define _LIBCPP_ELAST ELAST
+#elif defined(__linux__)
+#define _LIBCPP_ELAST 4095
+#elif defined(_NEWLIB_VERSION)
+#define _LIBCPP_ELAST __ELASTERROR
+#else
+// Warn here so that the person doing the libcxx port has an easier time:
+#warning This platform's ELAST hasn't been ported yet
+#endif
+
 #ifndef _LIBCPP_TRIVIAL_PAIR_COPY_CTOR
 #  define _LIBCPP_TRIVIAL_PAIR_COPY_CTOR 1
 #endif
 
 #ifndef _LIBCPP_STD_VER
 #  if  __cplusplus <= 201103L
 #    define _LIBCPP_STD_VER 11
 #  elif __cplusplus <= 201402L

src/ios.cpp

 //===-------------------------- ios.cpp -----------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
+#include "__config"
 #include "ios"
 #include "streambuf"
 #include "istream"
 #include "string"
 #include "__locale"
 #include "algorithm"
 #include "memory"
 #include "new"

 {
     return "iostream";
 }
 
 string
 __iostream_category::message(int ev) const
 {
     if (ev != static_cast<int>(io_errc::stream)
-#ifdef ELAST
-        && ev <= ELAST
-#elif defined(__linux__)
-        && ev <= 4095
-#endif  // ELAST
+#ifdef _LIBCPP_ELAST
+        && ev <= _LIBCPP_ELAST
+#endif  // _LIBCPP_ELAST
         )
         return __do_message::message(ev);
     return string("unspecified iostream_category error");
 }
 
 const error_category&
 iostream_category() _NOEXCEPT
 {

src/system_error.cpp

 //===---------------------- system_error.cpp ------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #define _LIBCPP_BUILDING_SYSTEM_ERROR
+#include "__config"
 #include "system_error"
 #include "string"
 #include "cstring"
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 // class error_category
 

 __generic_error_category::name() const _NOEXCEPT
 {
     return "generic";
 }
 
 string
 __generic_error_category::message(int ev) const
 {
-#ifdef ELAST
-    if (ev > ELAST)
+#ifdef _LIBCPP_ELAST
+    if (ev > _LIBCPP_ELAST)
       return string("unspecified generic_category error");
-#elif defined(__linux__)
-    if (ev > 4095)
-      return string("unspecified generic_category error");
-#endif  // ELAST
+#endif  // _LIBCPP_ELAST
     return __do_message::message(ev);
 }
 
 const error_category&
 generic_category() _NOEXCEPT
 {
     static __generic_error_category s;
     return s;

 __system_error_category::name() const _NOEXCEPT
 {
     return "system";
 }
 
 string
 __system_error_category::message(int ev) const
 {
-#ifdef ELAST
-    if (ev > ELAST)
-      return string("unspecified system_category error");
-#elif defined(__linux__)
-    if (ev > 4095)
+#ifdef _LIBCPP_ELAST
+    if (ev > _LIBCPP_ELAST)
       return string("unspecified system_category error");
-#endif  // ELAST
+#endif  // _LIBCPP_ELAST
     return __do_message::message(ev);
 }
 
 error_condition
 __system_error_category::default_error_condition(int ev) const _NOEXCEPT
 {
-#ifdef ELAST
-    if (ev > ELAST)
-      return error_condition(ev, system_category());
-#elif defined(__linux__)
-    if (ev > 4095)
+#ifdef _LIBCPP_ELAST
+    if (ev > _LIBCPP_ELAST)
       return error_condition(ev, system_category());
-#endif  // ELAST
+#endif  // _LIBCPP_ELAST
     return error_condition(ev, generic_category());
 }
 
 const error_category&
 system_category() _NOEXCEPT
 {
     static __system_error_category s;
     return s;