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 ↗

(On Diff #13081)

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

libcxx/src/ios.cpp

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

libcxx/src/system_error.cpp

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

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