Re: Fix compilation errors with libstdc++v3 for AVR target and allow --enable-libstdcxx

[Jonathan Wakely <jwakely@redhat.com>]

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On 23/12/16 13:18 -0200, Felipe Magno de Almeida wrote:
>On Fri, Dec 16, 2016 at 10:45 AM, Jonathan Wakely <jwakely@redhat.com> wrote:
>> On 15/12/16 21:41 -0300, Felipe Magno de Almeida wrote:
>>>
>>> Good point. Do you want me to update the patch with __men or go your way
>>> with the wrapper?
>
>Hello Jonathan,
>
>> I think my wrapper's too ugly :-)
>
>:)
>
>> So please follow the same approach as for tm_mon (pass __mem to the
>> function, the copy it to tm_mon if there was no error). That adds a
>> write and a branch for every extracted field, which I hope shouldn't
>> have too much impact.
>
>Please find it attached.

This has now been committed to trunk (with whitespace fixes) - thanks.


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commit 1cf9a4be2647a9bb54e763b74fb09d5a21706bd6
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Jan 10 12:43:29 2017 +0000

    Use temporary int objects to access struct tm members
    
    Call _M_extract_* functions family through temporary int objects, so
    it doesn't convert from lvalue to rvalue through a temporary in AVR
    because of the incompatible types used in AVR-Libc.
    
    This fixes compilation errors with AVR-Libc while compiling libstdc++
    for AVR target.
    
    2017-01-10  Felipe Magno de Almeida <felipe@expertisesolutions.com.br>
    
    	* include/bits/locale_facets_nonio.tcc
    	(time_get::_M_extract_via_format): Avoid compilation errors with
    	non-standard struct tm.

diff --git a/libstdc++-v3/include/bits/locale_facets_nonio.tcc b/libstdc++-v3/include/bits/locale_facets_nonio.tcc
index 2fcf234..a449c41 100644
--- a/libstdc++-v3/include/bits/locale_facets_nonio.tcc
+++ b/libstdc++-v3/include/bits/locale_facets_nonio.tcc
@@ -659,30 +659,38 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
 		  // Abbreviated weekday name [tm_wday]
 		  const char_type*  __days1[7];
 		  __tp._M_days_abbreviated(__days1);
-		  __beg = _M_extract_name(__beg, __end, __tm->tm_wday, __days1,
+		  __beg = _M_extract_name(__beg, __end, __mem, __days1,
 					  7, __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_wday = __mem;
 		  break;
 		case 'A':
 		  // Weekday name [tm_wday].
 		  const char_type*  __days2[7];
 		  __tp._M_days(__days2);
-		  __beg = _M_extract_name(__beg, __end, __tm->tm_wday, __days2,
+		  __beg = _M_extract_name(__beg, __end, __mem, __days2,
 					  7, __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_wday = __mem;
 		  break;
 		case 'h':
 		case 'b':
 		  // Abbreviated month name [tm_mon]
 		  const char_type*  __months1[12];
 		  __tp._M_months_abbreviated(__months1);
-		  __beg = _M_extract_name(__beg, __end, __tm->tm_mon, 
+		  __beg = _M_extract_name(__beg, __end, __mem,
 					  __months1, 12, __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_mon = __mem;
 		  break;
 		case 'B':
 		  // Month name [tm_mon].
 		  const char_type*  __months2[12];
 		  __tp._M_months(__months2);
-		  __beg = _M_extract_name(__beg, __end, __tm->tm_mon, 
+		  __beg = _M_extract_name(__beg, __end, __mem,
 					  __months2, 12, __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_mon = __mem;
 		  break;
 		case 'c':
 		  // Default time and date representation.
@@ -693,18 +701,22 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
 		  break;
 		case 'd':
 		  // Day [01, 31]. [tm_mday]
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_mday, 1, 31, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 1, 31, 2,
 					 __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_mday = __mem;
 		  break;
 		case 'e':
 		  // Day [1, 31], with single digits preceded by
 		  // space. [tm_mday]
 		  if (__ctype.is(ctype_base::space, *__beg))
-		    __beg = _M_extract_num(++__beg, __end, __tm->tm_mday, 1, 9,
+		    __beg = _M_extract_num(++__beg, __end, __mem, 1, 9,
 					   1, __io, __tmperr);
 		  else
-		    __beg = _M_extract_num(__beg, __end, __tm->tm_mday, 10, 31,
+		    __beg = _M_extract_num(__beg, __end, __mem, 10, 31,
 					   2, __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_mday = __mem;
 		  break;
 		case 'D':
 		  // Equivalent to %m/%d/%y.[tm_mon, tm_mday, tm_year]
@@ -715,13 +727,17 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
 		  break;
 		case 'H':
 		  // Hour [00, 23]. [tm_hour]
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_hour, 0, 23, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 0, 23, 2,
 					 __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_hour = __mem;
 		  break;
 		case 'I':
 		  // Hour [01, 12]. [tm_hour]
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_hour, 1, 12, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 1, 12, 2,
 					 __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_hour = __mem;
 		  break;
 		case 'm':
 		  // Month [01, 12]. [tm_mon]
@@ -732,8 +748,10 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
 		  break;
 		case 'M':
 		  // Minute [00, 59]. [tm_min]
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_min, 0, 59, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 0, 59, 2,
 					 __io, __tmperr);
+		  if (!__tmperr)
+		    __tm->tm_min = __mem;
 		  break;
 		case 'n':
 		  if (__ctype.narrow(*__beg, 0) == '\n')
@@ -752,11 +770,13 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
 		  // Seconds. [tm_sec]
 		  // [00, 60] in C99 (one leap-second), [00, 61] in C89.
 #if _GLIBCXX_USE_C99
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_sec, 0, 60, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 0, 60, 2,
 #else
-		  __beg = _M_extract_num(__beg, __end, __tm->tm_sec, 0, 61, 2,
+		  __beg = _M_extract_num(__beg, __end, __mem, 0, 61, 2,
 #endif
 					 __io, __tmperr);
+		  if (!__tmperr)
+		  __tm->tm_sec = __mem;
 		  break;
 		case 't':
 		  if (__ctype.narrow(*__beg, 0) == '\t')