64 bit g++ 5.4.0 bug

64 bit g++ 5.4.0 bug

[Takashi Yano]

Hello.

I have encountered a weird behaviour of g++ compiler.

If the following code is compiled with -ansi -O flags,
the resulting executable causes core dump.

This is caused only in 64 bit environment. In 32 bit
environment, it works as expected.

$ cat str.cc
#include <string>
int main()
{
        std::string s;
        s = "ABC";
        return 0;
}
$ g++ -ansi -O str.cc -o str
$ ./str
Abort (core dumped)
$

Is this known problem?

My environment is as follows.

uname -a
CYGWIN_NT-10.0 Express5800-S70 2.8.1(0.312/5/3) 2017-07-03 14:11 x86_64 Cygwin

g++ --version
g++ (GCC) 5.4.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Thank you in advance.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>

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Re: 64 bit g++ 5.4.0 bug

[Takashi Yano]

I have confirmed this problem disappears in Cygwin 2.8.2-1.

Thanks.

On Wed, 12 Jul 2017 22:12:12 +0900
Takashi Yano <takashi.yano@nifty.ne.jp> wrote:

> Hello.
> 
> I have encountered a weird behaviour of g++ compiler.
> 
> If the following code is compiled with -ansi -O flags,
> the resulting executable causes core dump.
> 
> This is caused only in 64 bit environment. In 32 bit
> environment, it works as expected.
> 
> $ cat str.cc
> #include <string>
> int main()
> {
>         std::string s;
>         s = "ABC";
>         return 0;
> }
> $ g++ -ansi -O str.cc -o str
> $ ./str
> Abort (core dumped)
> $
> 
> Is this known problem?
> 
> My environment is as follows.
> 
> uname -a
> CYGWIN_NT-10.0 Express5800-S70 2.8.1(0.312/5/3) 2017-07-03 14:11 x86_64 Cygwin
> 
> g++ --version
> g++ (GCC) 5.4.0
> Copyright (C) 2015 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> Thank you in advance.
> 
> -- 
> Takashi Yano <takashi.yano@nifty.ne.jp>
> 
> --
> Problem reports:       http://cygwin.com/problems.html
> FAQ:                   http://cygwin.com/faq/
> Documentation:         http://cygwin.com/docs.html
> Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
> 


-- 
Takashi Yano <takashi.yano@nifty.ne.jp>

--
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