[Bug libstdc++/15565] New: SLES9: leading + sign for unsigned int with showpos

["grigor at ca dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

On SLES9 when print using iostream the value of unsigned integral type with the 
preceding use of 'showpos' format flag - shows the sign '+'. 

This is a bug in the library on SLES9

Table 60 in subclause 22.2.2.2.2 from ISO/IEC 14882:1998 C++ standard implies 
that line 1 in the example program below should have the same output behaviour 
as line 2:

#include <iostream>
#include <stdio.h>

int main() {
        std::cout << std::showpos << 42U << std::endl;  // line 1
        printf("%+u\n", 42U);  // line 2
}

The C standard says of the '+' flag character:
"The result of a signed conversion always begins with a plus or minus sign."  
Since the conversion in the example above is unsigned, the + has no effect, and 
the correct output for this program is:

42
42

  Please, tell me if you really need the preprocessed file (*.i*). It is quite 
big, when the code to reproduce the problem is small.

Source code:     t.cpp
======================================================
#include <iostream>
#include <stdio.h>

int main() {
        std::cout << std::showpos << 42U << std::endl;  // line 1
        printf("%+u\n", 42U);  // line 2
}


Script to be run to reproduce the problem
======================================================
#!/usr/bin/ksh
#
rm -f *.o t
g++ "$@" -o t t.cpp 
echo Return code: $?
t 
echo Return code: $?


Actual output is:
======================================================
Reading specs from /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/specs
Configured with: ../configure --enable-threads=posix --prefix=/usr --with-local-
prefix=/usr/local --infodir=/usr/share/info --mandir=/usr/share/man --enable-
languages=c,c++,f77,objc,java,ada --disable-checking --libdir=/usr/lib --enable-
libgcj --with-gxx-include-dir=/usr/include/g++ --with-slibdir=/lib --with-
system-zlib --enable-shared --enable-__cxa_atexit --host=powerpc-suse-linux --
build=powerpc-suse-linux --target=powerpc-suse-linux --enable-targets=powerpc64-
suse-linux --enable-biarch
Thread model: posix
gcc version 3.3.3 (SuSE Linux)
 /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/cc1plus -E -D__GNUG__=3 -quiet -v -
D__GNUC__=3 -D__GNUC_MINOR__=3 -D__GNUC_PATCHLEVEL__=3 -D_GNU_SOURCE -
D__unix__ -D__gnu_linux__ -D__linux__ -Dunix -D__unix -Dlinux -D__linux -
Asystem=unix -Asystem=posix t.cpp t.ii
ignoring nonexistent directory "/usr/powerpc-suse-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/g++
 /usr/include/g++/powerpc-suse-linux
 /usr/include/g++/backward
 /usr/local/include
 /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/cc1plus -fpreprocessed t.ii -quiet -
dumpbase t.cpp -auxbase t -version -o t.s
GNU C++ version 3.3.3 (SuSE Linux) (powerpc-suse-linux)
        compiled by GNU C version 3.3.3 (SuSE Linux).
GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=32768
 /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/../../../../powerpc-suse-
linux/bin/as -a32 -mppc -V -Qy -o t.o t.s
GNU assembler version 2.15.90.0.1.1 (powerpc-suse-linux) using BFD version 
2.15.90.0.1.1 20040303 (SuSE Linux)
 /usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/collect2 --eh-frame-hdr -V -Qy -m 
elf32ppclinux -dynamic-linker /lib/ld.so.1 -o t /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../../../lib/crt1.o /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../../../lib/crti.o /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/crtbegin.o -L/usr/lib/gcc-lib/powerpc-suse-linux/3.3.3 -
L/usr/lib/gcc-lib/powerpc-suse-linux/3.3.3/../../../../powerpc-suse-
linux/lib/../lib -L/usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../../../powerpc-suse-linux/lib -L/usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../../../lib -L/usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../.. -L/lib/../lib -L/usr/lib/../lib t.o -lstdc++ -lm -lgcc_s -
lgcc -lc -lgcc_s -lgcc /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/crtsavres.o /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/crtend.o /usr/lib/gcc-lib/powerpc-suse-
linux/3.3.3/../../../../lib/crtn.o
GNU ld version 2.15.90.0.1.1 20040303 (SuSE Linux)
  Supported emulations:
   elf32ppclinux
   elf32ppc
   elf32ppcsim
   elf64ppc
Return code: 0
+42
42
Return code: 0

Expected output
===========================================
Return code: 0
42
42
Return code: 0

-- 
           Summary: SLES9: leading + sign for unsigned int with showpos
           Product: gcc
           Version: 3.3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: grigor at ca dot ibm dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15565