From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31663 invoked by alias); 26 Jun 2002 18:22:57 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 31607 invoked from network); 26 Jun 2002 18:22:53 -0000 Received: from unknown (HELO zwingli.cygnus.com) (208.245.165.35) by sources.redhat.com with SMTP; 26 Jun 2002 18:22:53 -0000 Received: by zwingli.cygnus.com (Postfix, from userid 442) id 8A45A5EA11; Wed, 26 Jun 2002 13:22:51 -0500 (EST) To: "Philippe De Muyter" Cc: Joel Brobecker , gdb-patches@sources.redhat.com Subject: Re: RFA: don't read coff line number unless we have symbols too References: <200206260803.g5Q83f028100@mail.macqel.be> From: Jim Blandy Date: Wed, 26 Jun 2002 11:22:00 -0000 In-Reply-To: <200206260803.g5Q83f028100@mail.macqel.be> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2002-06/txt/msg00542.txt.bz2 "Philippe De Muyter" writes: > Should the following lines not be kept outside of the conditional block ? > > info->min_lineno_offset = 0; > info->max_lineno_offset = 0; Sure, those can be moved outside. I was just thinking of those as just establishing the pre-condition for the loop that bfd_map_over_sections does. Those fields are never used outside the "read the line number table" block, and the worker function for bfd_map_over_sections --- effectively, the loop body. In that light, it makes more sense to keep them right next to the call, as they are in the original code. Here's a revised patch, if you prefer the initializations outside. 2002-03-06 Jim Blandy * coffread.c (coff_symfile_read): Don't try to read the line number table from disk if the image file doesn't have a symbol table; we'll never actually look at the info anyway, and Windows ships DLL's with bogus file offsets for the line number data. Index: gdb/coffread.c =================================================================== RCS file: /cvs/src/src/gdb/coffread.c,v retrieving revision 1.26 diff -c -r1.26 coffread.c *** gdb/coffread.c 19 Mar 2002 19:00:03 -0000 1.26 --- gdb/coffread.c 26 Jun 2002 18:19:07 -0000 *************** *** 593,608 **** /* End of warning */ - /* Read the line number table, all at once. */ info->min_lineno_offset = 0; info->max_lineno_offset = 0; - bfd_map_over_sections (abfd, find_linenos, (void *) info); ! make_cleanup (free_linetab_cleanup, 0 /*ignore*/); ! val = init_lineno (abfd, info->min_lineno_offset, ! info->max_lineno_offset - info->min_lineno_offset); ! if (val < 0) ! error ("\"%s\": error reading line numbers\n", name); /* Now read the string table, all at once. */ --- 593,626 ---- /* End of warning */ info->min_lineno_offset = 0; info->max_lineno_offset = 0; ! /* Only read line number information if we have symbols. ! ! On Windows NT, some of the system's DLL's have sections with ! PointerToLinenumbers fields that are non-zero, but point at ! random places within the image file. (In the case I found, ! KERNEL32.DLL's .text section has a line number info pointer that ! points into the middle of the string `lib\\i386\kernel32.dll'.) ! ! However, these DLL's also have no symbols. The line number ! tables are meaningless without symbols. And in fact, GDB never ! uses the line number information unless there are symbols. So we ! can avoid spurious error messages (and maybe run a little ! faster!) by not even reading the line number table unless we have ! symbols. */ ! if (num_symbols > 0) ! { ! /* Read the line number table, all at once. */ ! bfd_map_over_sections (abfd, find_linenos, (void *) info); ! ! make_cleanup (free_linetab_cleanup, 0 /*ignore*/); ! val = init_lineno (abfd, info->min_lineno_offset, ! info->max_lineno_offset - info->min_lineno_offset); ! if (val < 0) ! error ("\"%s\": error reading line numbers\n", name); ! } /* Now read the string table, all at once. */