From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26725 invoked by alias); 6 Jun 2003 06:22:06 -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 26669 invoked from network); 6 Jun 2003 06:22:05 -0000 Received: from unknown (HELO zenia.home) (12.223.225.216) by sources.redhat.com with SMTP; 6 Jun 2003 06:22:05 -0000 Received: by zenia.home (Postfix, from userid 5433) id F060D20FE6; Fri, 6 Jun 2003 01:22:27 -0500 (EST) To: Daniel Jacobowitz Cc: gdb-patches@sources.redhat.com Subject: Re: [ppc64-linux]: skip linkage functions References: <20030606000328.GA26538@nevyn.them.org> From: Jim Blandy Date: Fri, 06 Jun 2003 06:22:00 -0000 In-Reply-To: <20030606000328.GA26538@nevyn.them.org> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-06/txt/msg00226.txt.bz2 Daniel Jacobowitz writes: > On Thu, Jun 05, 2003 at 06:54:57PM -0500, Jim Blandy wrote: > > > > 2003-06-05 Jim Blandy > > > > Recognize and skip 64-bit PowerPC Linux linkage functions. > > * ppc-linux-tdep.c (insn_d, insn_ds, insn_xfx, read_insn, struct > > insn_pattern, insns_match_pattern, d_field, ds_field): New > > functions, macros, and types for working with PPC instructions. > > (ppc64_standard_linkage, PPC64_STANDARD_LINKAGE_LEN, > > ppc64_in_solib_call_trampoline, ppc64_standard_linkage_target, > > ppc64_skip_trampoline_code): New functions, variables, and macros > > for recognizing and skipping linkage functions. > > (ppc_linux_init_abi): Use ppc64_in_solib_call_trampoline and > > ppc64_skip_trampoline_code for the 64-bit PowerPC Linux ABI. > > Hmm. Probably not good enough for our needs, but is the > DW_AT_trampoline attribute useful here? I'll say it, so nobody else has to feel bad saying it: that patch is complete shite. I just can't see any other way to do it with the info I have. DW_AT_trampoline would allow me to implement in_solib_call_trampoline and skip_trampoline_code simply by consulting the debugging info, which would be eons better. And in generic code, to boot. The only thing is, the trampolines are generated by the linker, not the compiler. Could the linker contribute its own Dwarf compilation unit to .debug_info and .debug_abbrev? How should it decide which debugging format to use, and whether to emit anything at all? If we could get this working, we could start using it on other architectures, too.