libstdc++/7851: Problems with numeric_limits<wchar_t>::min() and max()

libstdc++/7851: Problems with numeric_limits<wchar_t>::min() and max()

[Peter Schmid]

>Number:         7851
>Category:       libstdc++
>Synopsis:       Problems with numeric_limits<wchar_t>::min() and max()
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Sep 07 10:26:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Peter Schmid
>Release:        3.3 20020905 (experimental)
>Organization:
TU Darmstadt
>Environment:
System: Linux kiste 2.4.18 #8 Sat Mar 9 15:33:15 CET 2002 i686 unknown
Architecture: i686
GNU ld version 2.13.90.0.4 20020814
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-languages=c,c++,f77,objc --enable-__cxa_atexit
>Description:
The values obtained for the smallest wchar_t from 
the numeric_limits facility and the wchar.h interface (WCHAR_MIN)
differ. The values WCHAR_MAX and numeric_limits<wchar_t>::max() are
not the same, either.
>How-To-Repeat:
source code wlimit.C
#include <wchar.h>
#include <limits>
#include <iostream>

int main()
{
  wchar_t wmin = WCHAR_MIN;
  wchar_t limits_wmin = std::numeric_limits<wchar_t>::min();

  std::cout << "Are WCHAR_MIN:" << wmin
       << " and numeric_limits<wchar_t>::min():" 
	    << limits_wmin << " the same? ";  
  (wmin == limits_wmin) ? 
    (std::cout << "yes\n") : (std::cout << "no\n");

  wchar_t wmax = WCHAR_MAX;
  wchar_t limits_wmax = std::numeric_limits<wchar_t>::max();

  std::cout << "Are WCHAR_MAX:" << wmax
       << " and numeric_limits<wchar_t>::max():" 
	    << limits_wmax << " the same? ";  
  (wmin == limits_wmax) ? 
    (std::cout << "yes\n") : (std::cout << "no\n");

}

Compiling wlimit.C

g++ -v -o wlimit wlimit.C -W -Wall
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/specs
Configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-languages=c,c++,f77,objc --enable-__cxa_atexit
Thread model: posix
gcc version 3.3 20020905 (experimental)
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/cc1plus -quiet -v -D__GNUC__=3 -D__GNUC_MINOR__=3 -D__GNUC_PATCHLEVEL__=0 -D_GNU_SOURCE wlimit.C -D__GNUG__=3 -quiet -dumpbase wlimit.C -auxbase wlimit -W -Wall -version -o /tmp/ccxQzMrh.s
GNU C++ version 3.3 20020905 (experimental) (i686-pc-linux-gnu)
	compiled by GNU C version 3.3 20020905 (experimental).
ignoring nonexistent directory "NONE/include"
ignoring nonexistent directory "/usr/local/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/c++/3.3
 /usr/local/include/c++/3.3/i686-pc-linux-gnu
 /usr/local/include/c++/3.3/backward
 /usr/local/include
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include
 /usr/include
End of search list.
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/../../../../i686-pc-linux-gnu/bin/as -V -Qy -o /tmp/cc8x3LiL.o /tmp/ccxQzMrh.s
GNU assembler version 2.13.90.0.4 (i686-pc-linux-gnu) using BFD version 2.13.90.0.4 20020814
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 -o wlimit /usr/lib/crt1.o /usr/lib/crti.o /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/crtbegin.o -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3 -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/../../../../i686-pc-linux-gnu/lib -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/../../.. /tmp/cc8x3LiL.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/crtend.o /usr/lib/crtn.o

Running wlimit
./wlimit
Are WCHAR_MIN:-2147483648 and numeric_limits<wchar_t>::min():0 the same? no
Are WCHAR_MAX:2147483647 and numeric_limits<wchar_t>::max():-1 the same? no

>Fix:
	
>Release-Note:
>Audit-Trail:
>Unformatted:
  >Severity:	serious 

Re: libstdc++/7851: Problems with numeric_limits<wchar_t>::min() and max()

[ljrittle]

Synopsis: Problems with numeric_limits<wchar_t>::min() and max()

State-Changed-From-To: open->closed
State-Changed-By: ljrittle
State-Changed-When: Wed Oct  9 15:30:25 2002
State-Changed-Why:
    Fixed on mainline according to PR submitter.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7851