RFA: Add libstdc++-v3 support for avr 4/7: fix locale_facets_nonio overloading on struct tm using template

[Jonathan Wakely]

On 21/10/14 16:53 +0100, Joern Rennecke wrote:
>

>libstdc++-v3:
>
>2013-06-14  Joern Rennecke <joern.rennecke@embecosm.com>
>
>	* include/bits/locale_facets_nonio.h (__tm_small_int): typedef/define.
>	(_M_extract_num): Templatize base type of __member argument.
>	(_M_extract_name): Change type of __member argument to __tm_small_int&.
>	* include/bits/locale_facets_nonio.tcc (_M_extract_via_format) <Z>:
>	Change type of __tmp to __tm_small_int.
>	(_M_extract_num): Templatize base type of __member argument.
>	(_M_extract_name): Change type of __member argument to __tm_small_int&.
>
>Index: include/bits/locale_facets_nonio.h
>===================================================================
>--- include/bits/locale_facets_nonio.h	(revision 216243)
>+++ include/bits/locale_facets_nonio.h	(working copy)
>@@ -42,6 +42,15 @@ namespace std _GLIBCXX_VISIBILITY(defaul
> {
> _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
>+#ifdef __AVR__
>+/* The struct tm defined in avr-libc/include/time.h uses int8_t for a number
>+   of fields.  To allow overload resolution to succeed, we need to adjust
>+   some data structures and functions to match.  */
>+typedef typeof (((tm*)0)->tm_sec) __tm_small_int;

I think this should probably use __typeof__ to work with
-Wpedantic-errors

>+#else /* For 100% mangling compatibility, use int directly.  */
>+#define __tm_small_int int
>+#endif

I'd prefer to always use a typedef, which can be a private member of
std::time_get, instead of defining a macro (even a macro using a
reserved name).

>   /**
>    *  @brief  Time format ordering data.
>    *  @ingroup locales
>@@ -654,14 +663,16 @@ namespace std _GLIBCXX_VISIBILITY(defaul
> 		  ios_base::iostate& __err, tm* __tm) const;
>
>       // Extract numeric component of length __len.
>+      template <typename _Member_t>
>       iter_type
>-      _M_extract_num(iter_type __beg, iter_type __end, int& __member,
>+      _M_extract_num(iter_type __beg, iter_type __end, _Member_t& __member,
> 		     int __min, int __max, size_t __len,
> 		     ios_base& __io, ios_base::iostate& __err) const;

I think this function is exported from the library, so turning it into
a template would be an ABI change.

>       // Extract any unique array of string literals in a const _CharT* array.
>       iter_type
>-      _M_extract_name(iter_type __beg, iter_type __end, int& __member,
>+      _M_extract_name(iter_type __beg, iter_type __end,
>+		      __tm_small_int& __member,
> 		      const _CharT** __names, size_t __indexlen,
> 		      ios_base& __io, ios_base::iostate& __err) const;

This part should be OK, since it only affects AVR.