From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 123612 invoked by alias); 23 Nov 2017 16:48:38 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 123155 invoked by uid 89); 23 Nov 2017 16:48:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.3 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KB_WAM_FROM_NAME_SINGLEWORD,SPF_HELO_PASS,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: smtp.polymtl.ca Received: from smtp.polymtl.ca (HELO smtp.polymtl.ca) (132.207.4.11) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 23 Nov 2017 16:48:27 +0000 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id vANGmKBn032472 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 23 Nov 2017 11:48:25 -0500 Received: by simark.ca (Postfix, from userid 112) id F08B21E585; Thu, 23 Nov 2017 11:48:20 -0500 (EST) Received: from simark.ca (localhost [127.0.0.1]) by simark.ca (Postfix) with ESMTP id 5F37A1E030; Thu, 23 Nov 2017 11:48:00 -0500 (EST) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 23 Nov 2017 16:48:00 -0000 From: Simon Marchi To: Pedro Alves Cc: Simon Marchi , gdb-patches@sourceware.org Subject: Re: [PATCH 2/4] remote: C++ify thread_item and threads_listing_context In-Reply-To: <59086522-06e7-c9a5-a2b3-799d4bc7fb59@redhat.com> References: <1511368867-19365-1-git-send-email-simon.marchi@ericsson.com> <1511368867-19365-3-git-send-email-simon.marchi@ericsson.com> <59086522-06e7-c9a5-a2b3-799d4bc7fb59@redhat.com> Message-ID: X-Sender: simon.marchi@polymtl.ca User-Agent: Roundcube Webmail/1.3.2 X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Thu, 23 Nov 2017 16:48:21 +0000 X-IsSubscribed: yes X-SW-Source: 2017-11/txt/msg00559.txt.bz2 On 2017-11-23 09:22, Pedro Alves wrote: > On 11/22/2017 04:41 PM, Simon Marchi wrote: >> From: Simon Marchi >> >> This patch C++ifies the thread_item and threads_listing_context >> structures in remote.c. thread_item::{extra,name} are changed to >> std::string. As a result, there's a bit of awkwardness in >> remote_update_thread_list, where we have to xstrdup those strings when >> filling the private_thread_info structure. This is removed in the >> following patch, where private_thread_info is also C++ified and its >> corresponding fields made std::string too. The xstrdup then becomes >> an >> std::move. >> >> Other than that there's nothing really special, it's a usual >> day-to-day >> VEC -> vector and char* -> std::string change. It allows removing a >> cleanup in remote_update_thread_list. >> >> Note that an overload of hex2bin that returns a gdb::byte_vector is >> added, with corresponding selftests. >> > > Awesome. Just a couple minor comments below. > >> --- a/gdb/remote.c >> +++ b/gdb/remote.c >> @@ -2972,25 +2972,33 @@ remote_threadlist_iterator (rmt_thread_action >> stepfunction, void *context, >> >> /* A thread found on the remote target. */ >> >> -typedef struct thread_item >> +struct thread_item >> { >> + thread_item (ptid_t ptid_) >> + : ptid (ptid_) >> + {} > > Could be explicit ? Yes. As you can see I don't have that reflex yet. I wish constructors were explicit by default though... >> + >> + ~thread_item () >> + { >> + delete thread_handle; >> + } >> + >> /* The thread's PTID. */ >> ptid_t ptid; >> >> /* The thread's extra info. May be NULL. */ >> - char *extra; >> + std::string extra; >> >> /* The thread's name. May be NULL. */ >> - char *name; >> + std::string name; >> >> /* The core the thread was running on. -1 if not known. */ >> - int core; >> + int core = -1; >> >> /* The thread handle associated with the thread. */ >> - gdb::byte_vector *thread_handle; >> + gdb::byte_vector *thread_handle = NULL; > > This could be made a non-pointer now, right? It is changed in the next patch, I thought it would be simpler to change it to non-pointer at the same time as the corresponding field in remote's private_thread_info. But now I realize that this state is not really good, because the destructor frees the vector and the default copy constructor/assignment operator are not deleted, so the vector can end up double-freed. In any case, I think we'll want to disable copy construction and copy assignment (to make sure we don't do copies by accident). If I keep the field as a pointer, then I would need to write a custom move constructor that will get removed in the next patch. So instead I'll make the field non-pointer, as you suggest, it ends up simpler. When transferring the thread_handle from the thread_item to the private_thread_info, this should be enough: info->thread_handle = new gdb::byte_vector (std::move (item.thread_handle)); which will get replaced by a simple std::move in the next patch. >> @@ -3109,37 +3105,28 @@ start_thread (struct gdb_xml_parser *parser, >> { > >> attr = xml_find_attribute (attributes, "name"); >> - item.name = attr != NULL ? xstrdup ((const char *) attr->value) : >> NULL; >> + if (attr != NULL) >> + item.name = (const char *) attr->value; > > Are you missing the xstrdup here? I guess this is related to > the awkwardness you mentioned. I don't think so, here item.name is an std::string, so the assignment does a copy. This copy is required I think, because attr->value won't exist after we're done parsing the XML. >> @@ -3150,8 +3137,8 @@ end_thread (struct gdb_xml_parser *parser, >> struct threads_listing_context *data >> = (struct threads_listing_context *) user_data; >> >> - if (body_text && *body_text) >> - VEC_last (thread_item_t, data->items)->extra = xstrdup >> (body_text); >> + if (body_text != NULL && *body_text != '\0') >> + data->items.back ().extra = body_text; > > And here? Same, extra is an std::string. Simon