From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11870 invoked by alias); 24 Apr 2018 19:16:58 -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 11857 invoked by uid 89); 24 Apr 2018 19:16:58 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.1 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx3-rdu2.redhat.com (HELO mx1.redhat.com) (66.187.233.73) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 24 Apr 2018 19:16:56 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 26152FB67F; Tue, 24 Apr 2018 19:16:55 +0000 (UTC) Received: from [127.0.0.1] (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 27CA72166BC6; Tue, 24 Apr 2018 19:16:53 +0000 (UTC) Subject: Re: [RFA 1/6] Add initial type alignment support To: Tom Tromey , gdb-patches@sourceware.org References: <20180424152222.8053-1-tom@tromey.com> <20180424152222.8053-2-tom@tromey.com> From: Pedro Alves Message-ID: Date: Tue, 24 Apr 2018 19:16:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180424152222.8053-2-tom@tromey.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2018-04/txt/msg00485.txt.bz2 Hi Tom, On 04/24/2018 04:22 PM, Tom Tromey wrote: > +/* * Number of bits allocated for alignment. */ > + > +#define TYPE_ALIGN_BITS 8 > + > /* * A ``struct type'' describes a particular instance of a type, with > some particular qualification. */ > > @@ -831,6 +835,14 @@ struct type > > struct type *chain; > > + /* * The alignment for this type. Zero means that the alignment was > + not specified in the debug info. Note that this is stored in a > + funny way: as the log base 2 (plus 1) of the alignment; so a > + value of 1 means the alignment is 1, and a value of 9 means the > + alignment is 256. */ > + > + unsigned align_log2 : TYPE_ALIGN_BITS; > + > /* * Flags specific to this instance of the type, indicating where > on the ring we are. > > @@ -841,7 +853,7 @@ struct type > instance flags are completely inherited from the target type. No > qualifiers can be cleared by the typedef. See also > check_typedef. */ > - int instance_flags; > + unsigned instance_flags : 9; > > /* * Length of storage for a value of this type. The value is the > expression in host bytes of what sizeof(type) would return. This > @@ -1292,6 +1304,26 @@ extern void allocate_gnat_aux_type (struct type *); > so you only have to call check_typedef once. Since allocate_value > calls check_typedef, TYPE_LENGTH (VALUE_TYPE (X)) is safe. */ > #define TYPE_LENGTH(thistype) (thistype)->length > + > +/* * Return the alignment of the type in bytes, or 0 if no alignment > + was specified. */ > +#define TYPE_RAW_ALIGN(thistype) type_raw_align (thistype) > + > +/* * Return the alignment of the type in bytes, or 0 if no alignment > + was specified. */ > +extern unsigned type_raw_align (struct type *); > + > +/* * Return the alignment of the type in bytes. Return 0 if the > + alignment cannot be determined; but note that this makes an effort > + to compute the alignment even it it was not specified in the debug > + info. */ > +extern unsigned type_align (struct type *); > + > +/* * Set the alignment of the type. The alignment must be a power of > + 2. Returns false if the given value does not fit in the available > + space in struct type. */ > +extern bool set_type_align (struct type *, ULONGEST); Are these represented in host bytes, or target addressable memory units? See comments around type::length and type_length_units. The comments above should be clarified in that direction. > +/* Implement the type_align gdbarch function. */ > + > +static ULONGEST > +i386_type_align (struct gdbarch *gdbarch, struct type *type) > +{ > + type = check_typedef (type); > + > + if (gdbarch_ptr_bit (gdbarch) == 32 && > + TYPE_CODE (type) == TYPE_CODE_INT && TYPE_LENGTH (type) > 4) > + return 4; && on the other line. Otherwise looks good to me, but I'd like to hear Simon's opinion. Thanks, Pedro Alves