From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22213 invoked by alias); 14 Apr 2002 16:52:06 -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 22193 invoked from network); 14 Apr 2002 16:52:05 -0000 Received: from unknown (HELO localhost.redhat.com) (24.112.240.27) by sources.redhat.com with SMTP; 14 Apr 2002 16:52:05 -0000 Received: from cygnus.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id AC70F3C3F; Sun, 14 Apr 2002 12:52:01 -0400 (EDT) Message-ID: <3CB9B3B1.90007@cygnus.com> Date: Sun, 14 Apr 2002 09:52:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:0.9.9) Gecko/20020328 X-Accept-Language: en-us, en MIME-Version: 1.0 To: gdb-patches@sources.redhat.com, Kevin Buettner Subject: [patch/rfa:rs6000] Don't use ->prev Content-Type: multipart/mixed; boundary="------------000102090209040702050801" X-SW-Source: 2002-04/txt/msg00503.txt.bz2 This is a multi-part message in MIME format. --------------000102090209040702050801 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-length: 1134 Hello, A number of targets contained code that tested ``->prev'' as part of doing their frame analysis. I think this ``cheating''. The objective of the frame analysis code is to create the ->prev frame using information from the current frame, not to use the still being created ->prev frame :-) Two cases - frame_chain for z8k and s390 - were, I think, simply wrong. The deleted z8k comment is telling - someone was 180 degrees out! :-) The other two cases - get_saved_regs for SPARC and rs6000 - are more interesting. The SPARC code clearly relies on there already being a ->prev frame so I've used get_prev_frame(). Since ->prev must exist, there is no risk of recursion - get_prev_frame() calling get_saved_regs() (yes, grotty). The rs6000 has me puzzled. I think the ->frame contains the address of the wrong end of the frame! If ->frame pointed at the frame's start, the code below wouldn't even be needed. Anyway, I've changed it to use frame_chain() (I don't see regressions on NetBSD/PPC. The other possability would be to risk a (recursive) get_prev_frame() call. Anyway, is the rs6000 ok? Andrew --------------000102090209040702050801 Content-Type: text/plain; name="diffs" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="diffs" Content-length: 4154 2002-04-14 Andrew Cagney * sparc-tdep.c (sparc_get_saved_register): Use get_prev_frame instead of ->prev. * z8k-tdep.c (z8k_frame_chain): Do not use ->prev. * s390-tdep.c (s390_frame_chain): Do not use ->prev. * rs6000-tdep.c (frame_get_saved_regs): Use rs6000_frame_chain() instead of ->prev. Index: rs6000-tdep.c =================================================================== RCS file: /cvs/src/src/gdb/rs6000-tdep.c,v retrieving revision 1.55 diff -u -r1.55 rs6000-tdep.c --- rs6000-tdep.c 12 Apr 2002 19:48:36 -0000 1.55 +++ rs6000-tdep.c 14 Apr 2002 16:48:56 -0000 @@ -1388,10 +1388,12 @@ && fdatap->cr_offset == 0 && fdatap->vr_offset == 0) frame_addr = 0; - else if (fi->prev && fi->prev->frame) - frame_addr = fi->prev->frame; else - frame_addr = read_memory_addr (fi->frame, wordsize); + /* NOTE: cagney/2002-04-14: The ->frame points to the inner-most + address of the current frame. Things might be easier if the + ->frame pointed to the outer-most address of the frame. In the + mean time, the address of the prev frame is used. */ + frame_addr = rs6000_frame_chain (fi); /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr. All fpr's from saved_fpr to fp31 are saved. */ Index: s390-tdep.c =================================================================== RCS file: /cvs/src/src/gdb/s390-tdep.c,v retrieving revision 1.43 diff -u -r1.43 s390-tdep.c --- s390-tdep.c 6 Apr 2002 00:02:50 -0000 1.43 +++ s390-tdep.c 14 Apr 2002 16:49:11 -0000 @@ -1009,9 +1009,7 @@ { CORE_ADDR prev_fp = 0; - if (thisframe->prev && thisframe->prev->frame) - prev_fp = thisframe->prev->frame; - else if (generic_find_dummy_frame (thisframe->pc, thisframe->frame)) + if (generic_find_dummy_frame (thisframe->pc, thisframe->frame)) return generic_read_register_dummy (thisframe->pc, thisframe->frame, S390_SP_REGNUM); else Index: sparc-tdep.c =================================================================== RCS file: /cvs/src/src/gdb/sparc-tdep.c,v retrieving revision 1.26 diff -u -r1.26 sparc-tdep.c --- sparc-tdep.c 12 Apr 2002 18:18:57 -0000 1.26 +++ sparc-tdep.c 14 Apr 2002 16:49:23 -0000 @@ -829,11 +829,11 @@ addr = frame1->frame + (regnum - G0_REGNUM) * SPARC_INTREG_SIZE - (FP_REGISTER_BYTES + 8 * SPARC_INTREG_SIZE); else if (regnum >= I0_REGNUM && regnum < I0_REGNUM + 8) - addr = (frame1->prev->extra_info->bottom + addr = (get_prev_frame (frame1)->extra_info->bottom + (regnum - I0_REGNUM) * SPARC_INTREG_SIZE + FRAME_SAVED_I0); else if (regnum >= L0_REGNUM && regnum < L0_REGNUM + 8) - addr = (frame1->prev->extra_info->bottom + addr = (get_prev_frame (frame1)->extra_info->bottom + (regnum - L0_REGNUM) * SPARC_INTREG_SIZE + FRAME_SAVED_L0); else if (regnum >= O0_REGNUM && regnum < O0_REGNUM + 8) @@ -875,11 +875,11 @@ { /* Normal frame. Local and In registers are saved on stack. */ if (regnum >= I0_REGNUM && regnum < I0_REGNUM + 8) - addr = (frame1->prev->extra_info->bottom + addr = (get_prev_frame (frame1)->extra_info->bottom + (regnum - I0_REGNUM) * SPARC_INTREG_SIZE + FRAME_SAVED_I0); else if (regnum >= L0_REGNUM && regnum < L0_REGNUM + 8) - addr = (frame1->prev->extra_info->bottom + addr = (get_prev_frame (frame1)->extra_info->bottom + (regnum - L0_REGNUM) * SPARC_INTREG_SIZE + FRAME_SAVED_L0); else if (regnum >= O0_REGNUM && regnum < O0_REGNUM + 8) Index: z8k-tdep.c =================================================================== RCS file: /cvs/src/src/gdb/z8k-tdep.c,v retrieving revision 1.7 diff -u -r1.7 z8k-tdep.c --- z8k-tdep.c 12 Apr 2002 18:18:57 -0000 1.7 +++ z8k-tdep.c 14 Apr 2002 16:49:25 -0000 @@ -160,10 +160,6 @@ CORE_ADDR z8k_frame_chain (struct frame_info *thisframe) { - if (thisframe->prev == 0) - { - /* This is the top of the stack, let's get the sp for real */ - } if (!inside_entry_file (thisframe->pc)) { return read_memory_pointer (thisframe->frame); --------------000102090209040702050801--