From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by sourceware.org (Postfix) with ESMTPS id 218473858C53 for ; Thu, 7 Apr 2022 09:02:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 218473858C53 Received: by mail-wm1-x331.google.com with SMTP id q20so3082105wmq.1 for ; Thu, 07 Apr 2022 02:02:57 -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=kMvfEyHNX/O9QpYhKEXiDlWpVB5c0ueaZ5YSTmMlPIE=; b=VAjZwREcS205FlST8uL4LnVUCPhj0hCwSTOrmmK2SMNIHN+D2H/oG52OfBuzistXkf aeQEHwSpvIVpONpFNwID2NMizhC8zKmAzA3+fNHvQr5/CzXewjt1lx6HU+oJVVSMc2rq aj1Scc/EfGcv06l7YQKiE1x1lVYgg+kDcTP4vLcNqzFsG/+I2wT0/M6SkIWeD5qgX7Gy UCBkA3w848/A1F9Dscrb4Z7hHFzo9aoSuEcsT2npW1erh7gWxf+DTfLJPNcZbrfZ0bE5 Ns8YwNxsGYPDh2QkujFByRfaeiDaviu5lyJu8JlE2v+GZuA04B/6x1XlJGeW+ENzfFvP FyWg== X-Gm-Message-State: AOAM5338xFKXyaygEIFAHzc4vN/Dw2kqi65iHeorYsVp6iiQxqTsa9OP yBSUxebslmMu+Dn2ImQsZE85AtYjpHaPGViLrds= X-Google-Smtp-Source: ABdhPJxxEDx5l53I8k2EZCJLuLSK7sb9+nMAqOXnsiZG2CzmqUXX6Zqs48y0mDe7/R2/Wqsmp4vvnQo0CEXS5K6mOdE= X-Received: by 2002:a1c:7216:0:b0:38e:7e58:8376 with SMTP id n22-20020a1c7216000000b0038e7e588376mr11590165wmc.35.1649322175703; Thu, 07 Apr 2022 02:02:55 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Jonathan Wakely Date: Thu, 7 Apr 2022 10:02:36 +0100 Message-ID: Subject: Re: libstdc++.so.0.29 contains undefined reference to libiconv To: Yubin Ruan Cc: "libstdc++" X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, HTML_MESSAGE, 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 Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Apr 2022 09:03:07 -0000 On Thu, 7 Apr 2022, 03:38 Yubin Ruan via Libstdc++, 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. And by the way, libiconv seems to only provide dynamic lib; there is > no libiconv.a; > > > Previously I have GCC10.2 compiled & installed. The libstdc++.so.0.28 > also contains undefined ref to libiconv* > > > nm -D /usr/local/mygcc/lib64/libstdc++.so.6.0.28 |grep -i iconv > U libiconv > U libiconv_close > U libiconv_open > > but compiling with libstdc++.so.6.0.28 does NOT require "-liconv". > > So, is there anything that I missed when compiling GCC11.2 which can > remove unnecessary dependency of libiconv ? > > Thanks, > Yubin >