Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
X-Injected-Via-Gmane: http://gmane.org/
To: cygwin AT cygwin DOT com
From: "Alexander Osipenko" <sip AT cos DOT ru>
Subject: Re: objdump : inaccurate demangling for foo(char* const)
Date: Fri, 19 Sep 2003 21:31:50 +0400
Lines: 103
Message-ID: <bkfekb$qkt$1@sea.gmane.org>
References: <bkdtn1$597$2 AT sea DOT gmane DOT org> <bke0qt$8l6$1 AT sea DOT gmane DOT org>
X-Complaints-To: usenet AT sea DOT gmane DOT org
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106

YES, there ARE a noticeable difference between GCC 3.2  and MS VisualC 7.1

struct A {
    virtual void foo(char* a) { std::cout << "A"; }
};

struct B: public A {
    virtual void foo(char* const a) { std::cout << "B"; }
};

int main() {
    B b;
    A* a = &b;
    a->foo("");
}

This example prints "A" in MSVC, and "B" in GCC.

In the plain case, the behavior is identical:

void foo1(char* a) {}
void foo2(char* const a) {}

From the caller function point of view, signatures of this functions (except name,
apparently)
should be identical - no matter, that parameter can't be changed _inside_ the function.
If you can pass a pointer to foo1() , so you can pass it to foo2() and vice versa.

If you declare pointers
  typedef void (*PF1)(char*);
  typedef void (*PF2)(char*const);
you can assign any foo to each PF.

IMHO, GCC seems  more consistent.

Of course, this is not the issue of cygwin port of GCC, you should ask GCC mailing list.
Let me know, if you'll find the correct answer.

=======
Alex.



"Alex Vinokur" <alexvn AT connect DOT to> wrote in message news:bke0qt$8l6$1 AT sea DOT gmane DOT org...
>
> "Alex Vinokur" <alexvn AT connect DOT to> wrote in message news:bkdtn1$597$2 AT sea DOT gmane DOT org...
> > ==========================================
> > Windows 2000 Professional
> > CYGWIN_NT-5.0 1.5.4(0.94/3/2)
> > GNU gcc version 3.2 20020927 (prerelease)
> > GNU objdump 2.14.90 20030901
> > ==========================================
> >
>
> Updated question about objdump.
>
> Low-level and user-level symbol names of foo2(char* const) are foo2(char*)
>
> --------- C++ code ---------
> void foo1 (char*) {}
> void foo2 (char* const) {}
> ----------------------------
>
>
> --------- objdump : Fragments ---------
> $ objdump -Cd t.o
>
> t.o:     file format pe-i386
>
> Disassembly of section .text:
>
> 00000000 <__Z4foo1Pc>:    // OK
>
> 00000006 <__Z4foo2Pc>:    // char*, not char* const
>
>
> $ objdump -d t.o
>
> t.o:     file format pe-i386
>
> Disassembly of section .text:
>
> 00000000 <foo1(char*)>:    // OK
>
>
> 00000006 <foo2(char*)>:    // Not char* const
>
> --------------------------------------
>
> So, is it inaccuracy or convention?
>
>
>    =====================================
>    Alex Vinokur
>      mailto:alexvn AT connect DOT to
>      http://mathforum.org/library/view/10978.html
>    =====================================
>
>
>
>




--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/