From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <eliz@gnu.org>
Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:470:142:3::10])
 by sourceware.org (Postfix) with ESMTPS id 8E4A6393C86A
 for <gdb@sourceware.org>; Sun, 24 Jan 2021 15:35:36 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 8E4A6393C86A
Received: from fencepost.gnu.org ([2001:470:142:3::e]:60034)
 by eggs.gnu.org with esmtp (Exim 4.90_1)
 (envelope-from <eliz@gnu.org>)
 id 1l3hQN-0003SY-7J; Sun, 24 Jan 2021 10:35:36 -0500
Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:2458
 helo=home-c4e4a596f7)
 by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256)
 (Exim 4.82) (envelope-from <eliz@gnu.org>)
 id 1l3hQ4-0006JN-8O; Sun, 24 Jan 2021 10:35:33 -0500
Date: Sun, 24 Jan 2021 17:35:21 +0200
Message-Id: <835z3m4abq.fsf@gnu.org>
From: Eli Zaretskii <eliz@gnu.org>
To: Peng Yu <pengyu.ut@gmail.com>
Cc: gdb@sourceware.org
In-Reply-To: <CABrM6wnr7vSR-HFxUGU+6wF9x-vBMNzOYhQi5EUHRpkGj_MBmA@mail.gmail.com>
 (message from Peng Yu via Gdb on Sun, 24 Jan 2021 09:06:10 -0600)
Subject: Re: Why does `disassemble` behave differently on Linux and Mac?
References: <CABrM6wnr7vSR-HFxUGU+6wF9x-vBMNzOYhQi5EUHRpkGj_MBmA@mail.gmail.com>
X-Spam-Status: No, score=1.6 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 RCVD_IN_BARRACUDACENTRAL, SPF_HELO_PASS, SPF_PASS,
 TXREP autolearn=no autolearn_force=no version=3.4.2
X-Spam-Level: *
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: gdb@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gdb mailing list <gdb.sourceware.org>
List-Unsubscribe: <https://sourceware.org/mailman/options/gdb>,
 <mailto:gdb-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/gdb/>
List-Post: <mailto:gdb@sourceware.org>
List-Help: <mailto:gdb-request@sourceware.org?subject=help>
List-Subscribe: <https://sourceware.org/mailman/listinfo/gdb>,
 <mailto:gdb-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Sun, 24 Jan 2021 15:35:37 -0000

> Date: Sun, 24 Jan 2021 09:06:10 -0600
> From: Peng Yu via Gdb <gdb@sourceware.org>
> 
> $ gcc -c func.c
> $ gdb -q func.o
> Reading symbols from func.o...
> (No debugging symbols found in func.o)
> (gdb) show disassembly-flavor
> The disassembly flavor is "att".
> (gdb) disassemble func
> No symbol table is loaded.  Use the "file" command.

I think you need to compile with -g.