From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <ablacktshirt@gmail.com>
Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com
 [IPv6:2a00:1450:4864:20::22c])
 by sourceware.org (Postfix) with ESMTPS id 1C3533860004
 for <libstdc++@gcc.gnu.org>; Thu,  7 Apr 2022 13:22:06 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1C3533860004
Received: by mail-lj1-x22c.google.com with SMTP id 17so7468948lji.1
 for <libstdc++@gcc.gnu.org>; Thu, 07 Apr 2022 06:22:06 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=x-gm-message-state:mime-version:references:in-reply-to:from:date
 :message-id:subject:to:cc;
 bh=via5we0vsXNPpCjFWROyRe7W9ZBIJ5fSvhHAZDt9C0w=;
 b=qK4ed2Rdc7p/XVBb+PBk412uY/y2Z4p6O11nEkRamHEfBhIgDpD+677acFVMdNguMT
 X2JholnWEKMuGtyicgG0biONukhCzGxw2mcz92i2LHTr1vzqI+/rkqNkI+6q8BHjyixN
 tctSbvYrIrLudVnpDtU737QU48T2o/DEBk6VbklfquR2BLbzdJLcRtpVqT4aNK9+iz93
 FBBYG+wzHiQbl0Hr0MiQfUAR9ZZJas09USncFjMdsngb+LivPT5/qUSr+o/QWasDcNeK
 OGkZDJcPQdEhbHgT+NQ72aONLiTmu+GEa/kcje8zezUFeMyBPmG8stxaq7iex+NkzoWv
 e75A==
X-Gm-Message-State: AOAM532CPrTjXHyEPqFoIyDzneNbO1TIVgBI2GsZJ6IjwdUoMoqNl/iA
 jNazsN/NqdtFJe4ASzt75Vey7p4UwiM0V3YI73gjVPHhuA==
X-Google-Smtp-Source: ABdhPJz4HEZb/z5e7+hYMUXmgiCwjYkDJq8M4dDx2zBqntpxp6q9raaYdDuX2jxR0Hxp1of4vWZZa+IPLN1oJ97LeYk=
X-Received: by 2002:a2e:9b4d:0:b0:244:da30:84c2 with SMTP id
 o13-20020a2e9b4d000000b00244da3084c2mr8883928ljj.359.1649337724732; Thu, 07
 Apr 2022 06:22:04 -0700 (PDT)
MIME-Version: 1.0
References: <CAJYFCiPYMyr=MhqkY6KDD7ReaDFue3B_DNc==+sFZdEc78CFDQ@mail.gmail.com>
 <CAH6eHdR5KAyvw2iZU8SqX+N0c=GwR3FPnRzPGNt302-vR4PQjQ@mail.gmail.com>
 <CAH6eHdRv6gvEqPjreSnX4=k_yrO+kzxMnG=zGaNVUg-YcetKzA@mail.gmail.com>
In-Reply-To: <CAH6eHdRv6gvEqPjreSnX4=k_yrO+kzxMnG=zGaNVUg-YcetKzA@mail.gmail.com>
From: Yubin Ruan <ablacktshirt@gmail.com>
Date: Thu, 7 Apr 2022 21:21:53 +0800
Message-ID: <CAJYFCiMniO4uKNvYOZ=42hkzBSB1yYA3OwXw4K-jGw3a-JwyWg@mail.gmail.com>
Subject: Re: libstdc++.so.0.29 contains undefined reference to libiconv
To: Jonathan Wakely <jwakely.gcc@gmail.com>
Cc: "libstdc++" <libstdc++@gcc.gnu.org>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=-0.1 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,
 SPF_HELO_NONE, SPF_PASS, TXREP,
 T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: libstdc++@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Libstdc++ mailing list <libstdc++.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/libstdc++>,
 <mailto:libstdc++-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/libstdc++/>
List-Post: <mailto:libstdc++@gcc.gnu.org>
List-Help: <mailto:libstdc++-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/libstdc++>,
 <mailto:libstdc++-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Apr 2022 13:22:16 -0000

On Thu, Apr 7, 2022 at 5:03 PM Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>
>
>
> On Thu, 7 Apr 2022, 10:02 Jonathan Wakely, <jwakely.gcc@gmail.com> wrote:
>>
>>
>>
>> On Thu, 7 Apr 2022, 03:38 Yubin Ruan via Libstdc++, <libstdc++@gcc.gnu.org> wrote:
>>>
>>> Hi,
>>>
>>> I compile GCC 11.2 and get a libstdc++.so.6.0.29 (installed in
>>> "/usr/local/mygcc/lib64/") but this shared lib contains undefined
>>> reference to libiconv_*.
>>>
>>> When I compile a hello world program using gcc11.2, I get the following error:
>>>
>>> > /usr/local/mygcc/bin/g++ -Wall -std=c++17 hw.cc -o hw
>>> /usr/local/mygcc/bin/../lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../lib64/libstdc++.so:
>>> undefined reference to `libiconv'
>>> /usr/local/mygcc/bin/../lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../lib64/libstdc++.so:
>>> undefined reference to `libiconv_close'
>>> /usr/local/mygcc/bin/../lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../lib64/libstdc++.so:
>>> undefined reference to `libiconv_open'
>>> collect2: error: ld returned 1 exit status
>>>
>>> Adding a "-liconv" flag will help this program compile.
>>>
>>> From ldd's output, the libstdc++.so does not has any dynamic reference
>>> to libiconv;
>>>
>>>   > ldd /usr/local/mygcc/lib64/libstdc++.so.6.0.29
>>>           linux-vdso.so.1 =>  (0x00007ffce1fea000)
>>>           libm.so.6 => /lib64/libm.so.6 (0x00007fefc74b8000)
>>>           libc.so.6 => /lib64/libc.so.6 (0x00007fefc70e9000)
>>>           /lib64/ld-linux-x86-64.so.2 (0x00007fefc7bd1000)
>>>           libgcc_s.so.1 =>
>>> /usr/local/$INSTALL_PREFX/lib64/libgcc_s.so.1 (0x00007fefc6ed1000)
>>>
>>> But from nm 's output, there are indeed undefined reference to libiconv*
>>>
>>>   > nm -D /usr/local/mygcc/lib64/libstdc++.so.6.0.29 |grep -i iconv
>>>                    U libiconv
>>>                    U libiconv_close
>>>                    U libiconv_open
>>>
>>> I already have libiconv installed under /usr/local when compiling
>>> GCC11.2, but this does not seems to help;
>>
>>
>> It doesn't help because that is the cause of the problem.
>>
>> Glibc defines the iconv routines that libstdc++ needs, and so you should not use libiconv on Linux systems using Glibc.
>
>
>
> There is an existing bug in bugzilla about this case.

Can you provide the bugzilla URL ?