From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1068 invoked by alias); 29 Nov 2007 19:39:21 -0000 Received: (qmail 1059 invoked by uid 22791); 29 Nov 2007 19:39:20 -0000 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (65.74.133.4) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 29 Nov 2007 19:39:14 +0000 Received: (qmail 5298 invoked from network); 29 Nov 2007 19:39:12 -0000 Received: from unknown (HELO localhost) (jimb@127.0.0.2) by mail.codesourcery.com with ESMTPA; 29 Nov 2007 19:39:12 -0000 To: Vladimir Prus Cc: gdb-patches@sources.redhat.com Subject: Re: Support constants for DW_AT_data_member_location References: <200711291254.14423.vladimir@codesourcery.com> From: Jim Blandy Date: Thu, 29 Nov 2007 19:39:00 -0000 In-Reply-To: <200711291254.14423.vladimir@codesourcery.com> (Vladimir Prus's message of "Thu, 29 Nov 2007 12:54:13 +0300") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-IsSubscribed: yes 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 X-SW-Source: 2007-11/txt/msg00554.txt.bz2 Vladimir Prus writes: > DWARF standard allows DW_AT_data_member_location value > to be a plain constant, but GDB does not. Is the following OK? A constant can have other FORMs, too; how about this? gdb/ChangeLog: 2007-11-29 Jim Blandy * dwarf2read.c (dwarf2_attr_is_constant): New function. (dwarf2_add_field): Use it to recognize DW_AT_data_member_location attributes with constant values; use dwarf2_get_attr_constant_value to get said values. diff -r c4f654de59cf gdb/dwarf2read.c --- a/gdb/dwarf2read.c Thu Nov 29 11:28:59 2007 -0800 +++ b/gdb/dwarf2read.c Thu Nov 29 11:33:57 2007 -0800 @@ -1012,6 +1012,8 @@ static void store_in_ref_table (unsigned static unsigned int dwarf2_get_ref_die_offset (struct attribute *, struct dwarf2_cu *); + +static int dwarf2_attr_is_constant (struct attribute *); static int dwarf2_get_attr_constant_value (struct attribute *, int); @@ -3380,8 +3382,11 @@ dwarf2_add_field (struct field_info *fip attr = dwarf2_attr (die, DW_AT_data_member_location, cu); if (attr) { - FIELD_BITPOS (*fp) = - decode_locdesc (DW_BLOCK (attr), cu) * bits_per_byte; + if (dwarf2_attr_is_constant (attr)) + FIELD_BITPOS (*fp) = dwarf2_get_attr_constant_value (attr, 0); + else + FIELD_BITPOS (*fp) = + decode_locdesc (DW_BLOCK (attr), cu) * bits_per_byte; } else FIELD_BITPOS (*fp) = 0; @@ -9008,6 +9013,26 @@ dwarf2_get_ref_die_offset (struct attrib return result; } +/* Return non-zero if ATTR's value falls in the 'constant' class, or + zero otherwise. When this function returns true, you can apply + dwarf2_get_attr_constant_value to it. */ +static int +dwarf2_attr_is_constant (struct attribute *attr) +{ + switch (attr->form) + { + case DW_FORM_sdata: + case DW_FORM_udata: + case DW_FORM_data1: + case DW_FORM_data2: + case DW_FORM_data4: + case DW_FORM_data8: + return 1; + default: + return 0; + } +} + /* Return the constant value held by the given attribute. Return -1 if the value held by the attribute is not constant. */