From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Kettenis To: kevinb@cygnus.com Cc: gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 05:26:00 -0000 Message-id: <200006021226.e52CQ2I01239@delius.kettenis.local> References: <1000602075018.ZM29997@ocotillo.lan> X-SW-Source: 2000-06/msg00015.html Date: Fri, 2 Jun 2000 00:50:19 -0700 From: Kevin Buettner Comma separated list with differing number of stars on the parameter names (sparc-tdep.c): static branch_type -isbranch (instruction, addr, target) - long instruction; - CORE_ADDR addr, *target; +isbranch (long instruction, CORE_ADDR addr, CORE_ADDR * target) { I guess you should tweak it some more such that it outputs CORE_ADDR *target instead of CORE_ADDR * target (note the spurious space between * and target). Mark >From kevinb@cygnus.com Fri Jun 02 08:16:00 2000 From: Kevin Buettner To: Mark Kettenis Cc: gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 08:16:00 -0000 Message-id: <1000602151553.ZM30578@ocotillo.lan> References: <1000602075018.ZM29997@ocotillo.lan> <200006021226.e52CQ2I01239@delius.kettenis.local> X-SW-Source: 2000-06/msg00016.html Content-length: 997 On Jun 2, 2:26pm, Mark Kettenis wrote: > Date: Fri, 2 Jun 2000 00:50:19 -0700 > From: Kevin Buettner > > Comma separated list with differing number of stars on the parameter > names (sparc-tdep.c): > > static branch_type > -isbranch (instruction, addr, target) > - long instruction; > - CORE_ADDR addr, *target; > +isbranch (long instruction, CORE_ADDR addr, CORE_ADDR * target) > { > > I guess you should tweak it some more such that it outputs > > CORE_ADDR *target > > instead of > > CORE_ADDR * target > > (note the spurious space between * and target). I noticed that. The space was put there by ``indent''. I would very much like to get rid of that space and it would be easy to make the perl script postprocess the ``indent'' output. But in doing so, we (obviously) generate different output than that of ``indent''. I suppose the other solution is to fix indent. :-) FYI, I'm using GNU indent 2.2.5. Kevin >From taylor@cygnus.com Fri Jun 02 08:40:00 2000 From: David Taylor To: Kevin Buettner Cc: gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 08:40:00 -0000 Message-id: <200006021539.LAA25912@texas.cygnus.com> X-SW-Source: 2000-06/msg00017.html Content-length: 4312 Date: Fri, 2 Jun 2000 00:50:19 -0700 From: Kevin Buettner [...] 2) ``protoize'' fails to convert functions disabled by ifdefs for the given platform. OTOH, on some other platform(s), these functions might not be disabled and would be converted. E.g, in breakpoint.c, on my GNU/Linux/x86 machine, protoize failed to convert create_longjmp_breakpoint() which is protected by an "#ifdef GET_LONGJMP_TARGET". With any solution, either you're going to have to check the results or you're going to have to hand convert some of the stuff. It's a tradeoff. From what you say below, your script also requires some later hand conversions. Does your script produce substantially less that needs to be hand converted? 3) ``protoize'' screws up on PTR types. E.g, in breakpoint.c, it converted static int cover_target_enable_exception_callback (arg) PTR arg; to static int cover_target_enable_exception_callback (__builtin_va_list arg) I consider this to be a more serious problem than the other complaints you have. 4) ``protoize'' does not reformat long argument lists. The lists end up entirely contained on one line. So... adopt the same solution for it that you chose to adopt for your script -- run indent on the output! For more information on protoize, see the "Running protoize" page: http://gcc.gnu.org/onlinedocs/gcc_2.html#SEC48 and the "Caveats of using protoize" page: http://gcc.gnu.org/onlinedocs/gcc_7.html#SEC135 I've used protoize before with good results. It was a fairly substantial project, though not as big as gdb. Two of my goals in creating the scripts for the PARAMS purging activities was that the scripts should be 1) easy to invoke and 2) require no hand editing of the output when done. I.e, you shouldn't have to edit any of the files that these scripts touch in order to fix I trust that "3)" is: "be conservative; not convert something if it can't be sure of getting it right". I'd much rather hand convert more of the code than have it make a subtle but incorrect change. errors so that you can build again. OTOH, the script may leave certain portions of the file alone that could possibly have be converted had the script been a little smarter. The things that the script fails to convert *will* have to be fixed later on (in order to complete the cleanup activity), either by another script, or by hand. For the PARAMS purging activity, I have spent a fair amount of time examining the diffs to make sure that this is indeed the case. (And I intend to do the same for the activity in this proposal.) Good. The reason that it is so important to avoid any hand edits is that we want people who have local repositories or checked out source trees to be able to run these conversion scripts against them so that merges will be less painful. (Even easy.) Agreed. With that said, keeping in mind the problems I noted above, I conclude that ``protoize'' is not the appropriate tool for us to use to convert function definitions in the gdb sources to their prototyped form. I only consider 3) -- screwing up on PTR types -- to be serious; the others seem minor enough. [...] Finally, I should note that I've done a test build on GNU/Linux/x86 and had no build problems, nor did I see any regressions when I ran the testsuite. The fix-decls script is below. I'd be interested in finding out if anyone else has a favorite script for doing this sort of thing. Other comments welcome too. I'd be tempted to do a build before running your script; stash away the object files; run the script; do another build; compare the object files... I consider the lack of (prototyped) function declarations to be more serious "problem" than the use of old style function definitions in old code. I'd like to see: . declarations near the top of every file (i.e., before the first function definition) for every static function in the file. . a declaration in an included header file for every non static function definition and for every non static function used. . changes to the default configuration to "encourage" developers to include the above declarations. >From davea@quasar.engr.sgi.com Fri Jun 02 09:17:00 2000 From: davea@quasar.engr.sgi.com (David B Anderson) To: gdb@sourceware.cygnus.com Subject: Re: does GDB support IRIX 64 bit executables? Date: Fri, 02 Jun 2000 09:17:00 -0000 Message-id: <200006021622.JAA05620@quasar.engr.sgi.com> X-SW-Source: 2000-06/msg00018.html Content-length: 952 On: irix 64 bit pointer apps and dwarf2 and gdb robert somerville writes: >i got this patch from : > Benjamin Gamsa The patch makes no distinction between address-size and offset-size in the dwarf2, but that is an essential distinction, I think. I think the patch as written will break alpha-64-bit-pointers-using-dwarf2 in dwarf2read.c That is, it will break any non-sgi target with 64bit pointers and dwarf2, as *only* SGI extended offsets/lengths in dwarf2 to 64bits for 64bit pointer apps. And the patch makes no provision for the coming dwarf2 revision with its compatible allowance of 32-bit-offset and 64-bit-offset dwarf2 in a single object file. I believe this is very easily dealt with. I hope to get to this to suggest a revised patch soon, but of course, promises are worthless :-) Regards, David B. Anderson davea@sgi.com danderson@acm.org http://reality.sgi.com/davea/ >From Will_Lentz@Trimble.COM Fri Jun 02 10:34:00 2000 From: Will Lentz To: Peter Reilley , gdb@sourceware.cygnus.com Subject: RE: Questions on GDB Date: Fri, 02 Jun 2000 10:34:00 -0000 Message-id: <8B0BE50D6F9AD01185A300A0C92BF455088393EE@US01XCH01.Trimble.COM> X-SW-Source: 2000-06/msg00019.html Content-length: 1327 Hi Pete, For a remote PPC target (through rproxy), I use: file xyz.elf target remote ip.addr:port load run It's really cool that you ported the Macraigor DLL to Linux! I think more people would use the Wiggler if your port was made available :-). Will > -----Original Message----- > From: Peter Reilley [ mailto:micrio@mv.com ] > Sent: Thursday, June 01, 2000 2:24 PM > To: gdb@sourceware.cygnus.com > Subject: Questions on GDB > > > I have a few questions on the operation of GDB with the Wiggler > and a PowerPC target. > > I have ported the Macraigor DLL from MS Windows to Linux and > am attempting to get GDB working. I can read and write registers > and memory in the PPC target. I have a small test program that > I compiled with GCC configured as a cross compiler for the PPC. > I can use the "load" command and have the binary load properly > in the target memory. I can use the "symbol-file" command to > load the symbols. The "file" command will load the binary but > it seems to have a base address in the host and not the target. > The "run" and "step" commands do not seem to work. > > Anyway, what are the commands that you used to load and execute > a binary in a target under Windows. The documentation that I found > on the internet is conflicting. > > Thanks, > Pete. > > > > > >From jtc@redback.com Fri Jun 02 10:44:00 2000 From: jtc@redback.com (J.T. Conklin) To: Kevin Buettner Cc: Mark Kettenis , gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 10:44:00 -0000 Message-id: <5mya4om115.fsf@jtc.redback.com> References: <1000602075018.ZM29997@ocotillo.lan> <200006021226.e52CQ2I01239@delius.kettenis.local> <1000602151553.ZM30578@ocotillo.lan> X-SW-Source: 2000-06/msg00020.html Content-length: 799 >>>>> "Kevin" == Kevin Buettner writes: Kevin> I noticed that. The space was put there by ``indent''. I Kevin> would very much like to get rid of that space and it would be Kevin> easy to make the perl script postprocess the ``indent'' output. Kevin> But in doing so, we (obviously) generate different output than Kevin> that of ``indent''. Kevin> Kevin> I suppose the other solution is to fix indent. :-) You can tell indent about all the types defined by typedef with -T option, and then it won't add the extra space. It shouldn't be too difficult to identify all the types. It might be useful for us to maintain an indent.pro file that has these definitions so that additional runs of indent don't add back the space. --jtc -- J.T. Conklin RedBack Networks >From kevinb@cygnus.com Fri Jun 02 12:10:00 2000 From: Kevin Buettner To: David Taylor Cc: gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 12:10:00 -0000 Message-id: <1000602191042.ZM30936@ocotillo.lan> References: <200006021539.LAA25912@texas.cygnus.com> X-SW-Source: 2000-06/msg00021.html Content-length: 7094 On Jun 2, 11:39am, David Taylor wrote: > With any solution, either you're going to have to check the results or > you're going to have to hand convert some of the stuff. It's a > tradeoff. From what you say below, your script also requires some > later hand conversions. Yes. But, it's conservative in that it won't break your builds. (Or at least that's the intent.) > Does your script produce substantially less that needs to be hand > converted? I only ran protoize on breakpoint.c to see what the problems were. This was the file that required the most conversion, however, so hopefully it's a good representative sample. For this file, protoize converted 126 function declarations and fix-decls converted 138. In addition, not counting reformatting, the protoized version of breakpoint.c would require 5 hand edits in order to fix problems introduced in the conversion. The fix-decls version requires 0 hand edits. After conversion, the protoized version of breakpoint.c still had 15 functions which would need to be converted by hand (or some other tool) whereas the fix-decls version had only 3. Here's a table to summarizing the above: breakpoint.c conversion | protoize | fix-decls | ----------------------------------------------+----------+-----------+ Functions converted | 126 | 138 | ----------------------------------------------+----------+-----------+ Hand edits needed afterwards to fix problems | | | in the conversion process | 5 | 0 | ----------------------------------------------+----------+-----------+ Functions remaining to be converted | 15 | 3 | ----------------------------------------------+----------+-----------+ Total number of hand edits required | 20 | 3 | ----------------------------------------------+----------+-----------+ Recall that over all of the gdb sources, fix-decls converted slightly over 5200 declarations. I believe that there are only around 140 left to consider. This is somewhat higher than I would like and I may be able to reduce it somewhat by making the script a little bit smarter. But I also want to be certain that no errors are introduced in the process. I should note that there are many settings where protoize is a completely acceptable (and probably better) tool. With gdb, however, we have a lot of developers scattered across the globe who need to be able to deterministically apply the same transformations to their sources in order to make merges and checkins easier. With protoize, I think it's going be be difficult to guarantee determinism since the results will vary depending upon which platform you use to do the transformation. > 3) ``protoize'' screws up on PTR types. E.g, in breakpoint.c, it > converted > > static int > cover_target_enable_exception_callback (arg) > PTR arg; > > to > > static int > cover_target_enable_exception_callback (__builtin_va_list arg) > > I consider this to be a more serious problem than the other complaints > you have. I think the setup issue is important too. (I don't know if it's more serious though.) As I mentioned in my first point (which is no longer quoted), you have to do a configure in the source directory above gdb in order to to properly run protoize or else it complains that it can't find certain header files. Also, you need to make sure that the bfd header files are generated before you start. None of these problems are insurmountable, but to do things safely with protoize, and in order to avoid polluting your sources with files that belong in a build tree, it would be necessary for a script using protoize to make a complete copy of the source tree somewhere else in order to do the work. > 4) ``protoize'' does not reformat long argument lists. The lists > end up entirely contained on one line. > > So... adopt the same solution for it that you chose to adopt for your > script -- run indent on the output! Granted. A suitably imaginative script could identify just the lines that protoize touched and reformat those. I don't think we want to run indent on entire files however, at least not for this activity. > For more information on protoize, see the "Running protoize" page: > > http://gcc.gnu.org/onlinedocs/gcc_2.html#SEC48 > > and the "Caveats of using protoize" page: > > http://gcc.gnu.org/onlinedocs/gcc_7.html#SEC135 > > I've used protoize before with good results. It was a fairly > substantial project, though not as big as gdb. Okay. Out of curiousity, did the project in question have a large number of active developers? (This doesn't necessarily matter, but I think it's probably easier to manage this kind of thing when only a handful of developers are affected.) > Two of my goals in creating the scripts for the PARAMS purging > activities was that the scripts should be 1) easy to invoke and 2) > require no hand editing of the output when done. I.e, you shouldn't > have to edit any of the files that these scripts touch in order to fix > > I trust that "3)" is: > > "be conservative; not convert something if it can't be sure > of getting it right". You're right. I should have mentioned this. > I'd much rather hand convert more of the code than have it make a > subtle but incorrect change. I agree completely. [...] > Finally, I should note that I've done a test build on GNU/Linux/x86 > and had no build problems, nor did I see any regressions when I ran > the testsuite. > > The fix-decls script is below. I'd be interested in finding out if > anyone else has a favorite script for doing this sort of thing. Other > comments welcome too. > > I'd be tempted to do a build before running your script; stash away the > object files; run the script; do another build; compare the object > files... Good idea. I'll have to see what gcc does to compare object files. (I don't think a simple cmp works for ELF files.) > I consider the lack of (prototyped) function declarations to be more > serious "problem" than the use of old style function definitions in > old code. I'd like to see: > > . declarations near the top of every file (i.e., before the first > function definition) for every static function in the file. > > . a declaration in an included header file for every non static > function definition and for every non static function used. > > . changes to the default configuration to "encourage" developers to > include the above declarations. I don't disagree, but I think that adding prototypes for everything should be a separate activity. The question is whether it should occur before the activity covered by my proposal. And if it should occur before, once again, we'll need to find a way to help automate the process because if we attempt to do it incrementally by hand over a period of time, it is likely that it'll never get done. Kevin >From taylor@cygnus.com Fri Jun 02 13:11:00 2000 From: David Taylor To: Kevin Buettner Cc: gdb@sourceware.cygnus.com Subject: Re: Proposal: convert function definitions to prototyped form Date: Fri, 02 Jun 2000 13:11:00 -0000 Message-id: <200006022010.QAA25997@texas.cygnus.com> X-SW-Source: 2000-06/msg00022.html Content-length: 4318 Date: Fri, 2 Jun 2000 12:10:42 -0700 From: Kevin Buettner On Jun 2, 11:39am, David Taylor wrote: > 3) ``protoize'' screws up on PTR types. E.g, in breakpoint.c, it > converted > > static int > cover_target_enable_exception_callback (arg) > PTR arg; > > to > > static int > cover_target_enable_exception_callback (__builtin_va_list arg) > > I consider this to be a more serious problem than the other complaints > you have. I think the setup issue is important too. (I don't know if it's more serious though.) As I mentioned in my first point (which is no longer quoted), you have to do a configure in the source directory above gdb Sorry, I didn't consider it relevant to what I was replying to. in order to to properly run protoize or else it complains that it can't find certain header files. Also, you need to make sure that the bfd header files are generated before you start. None of these problems are insurmountable, but to do things safely with protoize, and in order to avoid polluting your sources with files that belong in a build tree, it would be necessary for a script using protoize to make a complete copy of the source tree somewhere else in order to do the work. I don't consider the setup issue to be a big issue. It requires some time, but it doesn't require much human time. Configure in the source tree, then build. Setup done. During the commit phase, you don't commit anything that is new -- you only commit files that existed prior to doing the configure. No separate tree needed. > 4) ``protoize'' does not reformat long argument lists. The lists > end up entirely contained on one line. > > So... adopt the same solution for it that you chose to adopt for your > script -- run indent on the output! Granted. A suitably imaginative script could identify just the lines that protoize touched and reformat those. I don't think we want to run indent on entire files however, at least not for this activity. Since Stan previously ran indent on all of the files, re-running it *should* produce no change for stuff that hasn't changed. Should produce no change. I'm not saying it won't. If it changes its own output when presented with it as input, I would consider that a bug. > I've used protoize before with good results. It was a fairly > substantial project, though not as big as gdb. Okay. Out of curiousity, did the project in question have a large number of active developers? (This doesn't necessarily matter, but I think it's probably easier to manage this kind of thing when only a handful of developers are affected.) It was at a former company. There were a small number of active developers all within the company. The total project was around 200-250K lines of code. There was a great deal less use of #if within the sources than there is in GDB... [...] I don't disagree, but I think that adding prototypes for everything should be a separate activity. The question is whether it should occur before the activity covered by my proposal. And if it should occur before, once again, we'll need to find a way to help automate the process because if we attempt to do it incrementally by hand over a period of time, it is likely that it'll never get done. I agree that it should be a separate activity. I think that your script is a good thing. And due to the amount of hand editing that appears to be necessary with protoize vs the amount that appears to be necessary with your script, I think we should use your script. Ultimately, though, since you're doing the work, you get to select the tool. So long as it is fairly reliable and reasonably quick (quick in terms of *your time*, not in terms of *elapsed time*), it doesn't ultimately matter to me what tool you use. (Which is not to say that I am not interested in knowing what tool you use -- I am interested.) Like I said, I think your script is a good thing. And I look forward to you using it to protoize the bulk of the GDB sources. Kevin David >From kettenis@wins.uva.nl Fri Jun 02 13:58:00 2000 From: Mark Kettenis To: gdb@sourceware.cygnus.com Subject: handling unexpected debugging unformation Date: Fri, 02 Jun 2000 13:58:00 -0000 Message-id: <200006022058.e52KwS213519@delius.kettenis.local> X-SW-Source: 2000-06/msg00023.html Content-length: 1842 Struggling with the misconfigured GCC 2.95.2 used by FreeBSD/Alpha as its system compiler revealed some weaknesses in GDB with respect to unexpected debugging information. Some extra stabs present in the stabs-in-ecoff .mdebug section of an Alpha ELF executable caused GDB to crash. The problematic stabs in question are: * N_BINCL stabs: These cause add_new_header_files to be called, but since init_header_files() hasn't been called for stabs-in-ecoff, GDB tries to dereference a null pointer. There are several possible solutions, and I'll need some help choosing between them :-). Hence a few questions: - Should N_BINCL stabs be supported in stabs-in-ecoff? - Is it acceptable to export free_header_files() and init_header_files() from dbxread.c? - Shouldn't mdebugread.c:elfmdebug_build_psymtabs() call stabsread_new_init() and buildsym_new_init()? - What about mdebug_build_psymtabs()? * An extra blank N_SO stab (emitted by GCC for normal stabs-in-ELF): mdebugread.c:psymtab_to_symtab_1() iterates over all stabs symbols, calling dbxread.c:process_one_symbol() for them. If process_one_symbol() sees an N_SO stab it will call end_symtab() if we've seen an N_SO before, and then calls start_symtab() if the N_SO stab isn't blank. After the iteration psymtab_to_symtab_1() also calls end_symtab() and uses its return value. The problem is that the blank N_SO stab already finishes creating the symbol table. The end_symtab() in psymtab_to_symtab_1() tries to do that again, freeing already freed memory blocks, which again crashed GDB. (The extra blank N_SO stab in normal ELF objects seems never to be passed to process_one_symbal()). Is there a way we can make this a bit more robust? Would setting subfiles to NULL in buildsymtab.c:end_symtab() be sufficient? Mark