From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4013 invoked by alias); 16 Oct 2003 19:06:17 -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 3875 invoked from network); 16 Oct 2003 19:06:15 -0000 Received: from unknown (HELO touchme.toronto.redhat.com) (207.219.125.105) by sources.redhat.com with SMTP; 16 Oct 2003 19:06:15 -0000 Received: from redhat.com (toocool.toronto.redhat.com [172.16.14.72]) by touchme.toronto.redhat.com (Postfix) with ESMTP id 922438003F4; Thu, 16 Oct 2003 15:06:14 -0400 (EDT) Message-ID: <3F8EEC26.60101@redhat.com> Date: Thu, 16 Oct 2003 19:06:00 -0000 From: "J. Johnston" Organization: Red Hat Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Cagney Cc: gdb-patches@sources.redhat.com Subject: Re: RFA: frame id enhancement References: <3F81DB50.6020202@redhat.com> <3F8DB78A.4090409@redhat.com> <3F8DD464.6050201@redhat.com> <3F8EC2B3.5040100@redhat.com> In-Reply-To: <3F8EC2B3.5040100@redhat.com> Content-Type: multipart/mixed; boundary="------------080904000307010502050605" X-SW-Source: 2003-10/txt/msg00559.txt.bz2 This is a multi-part message in MIME format. --------------080904000307010502050605 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-length: 3232 Andrew Cagney wrote: > >>> int >>> frame_id_inner (struct frame_id l, struct frame_id r) >>> { >>> int inner; >>> if (l.stack_addr == 0 || r.stack_addr == 0) >>> /* Like NaN, any operation involving an invalid ID always fails. */ >>> inner = 0; >>> else >>> /* Only return non-zero when strictly inner than. Note that, per >>> comment in "frame.h", there is some fuzz here. Frameless >>> functions are not strictly inner than (same .stack but >>> different .code). */ >>> inner = INNER_THAN (l.stack_addr, r.stack_addr); >>> if (frame_debug) >>> { >>> fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l="); >>> fprint_frame_id (gdb_stdlog, l); >>> fprintf_unfiltered (gdb_stdlog, ",r="); >>> fprint_frame_id (gdb_stdlog, r); >>> fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner); >>> } >>> return inner; >>> } >>> >>> >>> does SPECIAL_ADDR add further ordering? If it doesn't then the >>> comment needs to be updated (and the description in "frame.h" >>> clarified). > > >> >> >> Another good point. Yes, it does in this case. Two frames could both >> not use the stack but one will definitely move the special_addr. I >> need to add a SPECIAL_INNER_THAN macro which can default to false and >> must be overridden by the platform. > > > Is there real value add in having SPECIAL_INNER_THAN though? It would > only be called by frame_id_inner. Looking at how that method is used: > >> frame.c:354: if (frame_id_inner (id, this)) > > In frame_find_by_id: Its sole purpose is to act as a short circuit for > the unlikely case where the ID isn't present in the frame. A stonger > frame_id_inner has little value add. > >> frame.c:1909: && frame_id_inner (get_frame_id (this_frame), > > In get_prev_frame: Its a sainity check to detect what appears to be a > badly corrupt stack. Marginal value add? > >> infrun.c:2094: && (frame_id_inner (get_frame_id >> (get_current_frame ()), > > Commented out. > >> infrun.c:2383: if (frame_id_inner (current_frame, step_frame_id)) > > Received a signal. Given that a predicate to the call is: > && INNER_THAN (read_sp (), step_sp)) > the code's assumed that a signal modifies frame_id.stack_addr, so there > is no value add. It might be useful to clarify this assumption though. > >> infrun.c:2477: && frame_id_inner (step_frame_id, > > It's the reverse of infrun.c:2383 where the inferior is falling out of a > singnal trampoline, I think the assumptions again hold. > >> infrun.c:2641: if (!(frame_id_inner (current_frame, step_frame_id))) > > "Trust me" there's no value add. While the comment reads: > /* In the case where we just stepped out of a function into the > middle of a line of the caller, continue stepping, but > step_frame_id must be modified to current frame */ > The test also updates step_frame_id when switching between frameless > stackless leaf function. The extra test wouldn't fix that problem. I'll > try to remember to add some comments to that code. > > Andrew > Ok, that simplifies things. I have included a revised patch that allows for the wild-card scenario. Ok? -- Jeff J. --------------080904000307010502050605 Content-Type: text/plain; name="frame-special.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="frame-special.patch" Content-length: 3972 Index: frame.c =================================================================== RCS file: /cvs/src/src/gdb/frame.c,v retrieving revision 1.145 diff -u -r1.145 frame.c --- frame.c 2 Oct 2003 20:28:29 -0000 1.145 +++ frame.c 6 Oct 2003 21:07:51 -0000 @@ -144,9 +144,10 @@ void fprint_frame_id (struct ui_file *file, struct frame_id id) { - fprintf_unfiltered (file, "{stack=0x%s,code=0x%s}", + fprintf_unfiltered (file, "{stack=0x%s,code=0x%s,special=0x%s}", paddr_nz (id.stack_addr), - paddr_nz (id.code_addr)); + paddr_nz (id.code_addr), + paddr_nz (id.special_addr)); } static void @@ -256,14 +257,22 @@ const struct frame_id null_frame_id; /* All zeros. */ struct frame_id -frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) +frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr, + CORE_ADDR special_addr) { struct frame_id id; id.stack_addr = stack_addr; id.code_addr = code_addr; + id.special_addr = special_addr; return id; } +struct frame_id +frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) +{ + return frame_id_build_special (stack_addr, code_addr, 0); +} + int frame_id_p (struct frame_id l) { @@ -288,6 +297,9 @@ eq = 0; else if (l.stack_addr != r.stack_addr) /* If .stack addresses are different, the frames are different. */ + eq = 0; + else if (l.special_addr != r.special_addr) + /* If .special addresses are different, the frames are different. */ eq = 0; else if (l.code_addr == 0 || r.code_addr == 0) /* A zero code addr is a wild card, always succeed. */ Index: frame.h =================================================================== RCS file: /cvs/src/src/gdb/frame.h,v retrieving revision 1.109 diff -u -r1.109 frame.h --- frame.h 28 Sep 2003 22:32:19 -0000 1.109 +++ frame.h 6 Oct 2003 21:07:52 -0000 @@ -95,8 +95,6 @@ is used. Watch out for all the legacy targets that still use the function pointer register or stack pointer register. They are wrong. */ - /* NOTE: cagney/2002-11-16: The ia64 has two stacks and hence two - frame bases. This will need to be expanded to accomodate that. */ CORE_ADDR stack_addr; /* The frame's code address. This shall be constant through out the lifetime of the frame. While the PC (a.k.a. resume address) @@ -104,6 +102,12 @@ Typically, it is set to the address of the entry point of the frame's function (as returned by frame_func_unwind(). */ CORE_ADDR code_addr; + /* The frame's special address. This shall be constant through out the + lifetime of the frame. This is used for architectures that may have + frames that have the same stack_addr and code_addr but are distinct + due to some other qualification (e.g. the ia64 uses a register + stack which is distinct from the memory stack). */ + CORE_ADDR special_addr; }; /* Methods for constructing and comparing Frame IDs. @@ -120,9 +124,19 @@ /* Construct a frame ID. The first parameter is the frame's constant stack address (typically the outer-bound), and the second the frame's constant code address (typically the entry point) (or zero, - to indicate a wild card). */ + to indicate a wild card). The special identifier address is + defaulted to zero. */ extern struct frame_id frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr); + +/* Construct a special frame ID. The first parameter is the frame's constant + stack address (typically the outer-bound), the second is the + frame's constant code address (typically the entry point) (or zero, + to indicate a wild card), and the third parameter is the frame's + special identifier address. */ +extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr, + CORE_ADDR code_addr, + CORE_ADDR special_addr); /* Returns non-zero when L is a valid frame (a valid frame has a non-zero .base). */ --------------080904000307010502050605--