Fix description of --stabs switch
[binutils-gdb.git] / gdb / TODO
1 If you find inaccuracies in this list, please send mail to
2 gdb-patches@sourceware.cygnus.com. If you would like to work on any
3 of these, you should consider sending mail to the same address, to
4 find out whether anyone else is working on it.
5
6
7 Known problems in GDB 5.0
8 =========================
9
10 Below is a list of problems identified during the GDB 5.0 release
11 cycle. People hope to have these problems fixed in a follow-on
12 release.
13
14 --
15
16 The BFD directory requires bug-fixed AUTOMAKE et.al.
17
18 AUTOMAKE 1.4 incorrectly set the TEXINPUTS environment variable. It
19 contained the full path to texinfo.tex when it should have only
20 contained the directory. The bug has been fixed in the current
21 AUTOMAKE sources. Automake snapshots can be found in:
22 ftp://sourceware.cygnus.com/pub/gdb/snapshots
23 and ftp://sourceware.cygnus.com/pub/binutils
24
25 --
26
27 RFD: infrun.c: No bpstat_stop_status call after proceed over break?
28 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00665.html
29
30 GDB misses watchpoint triggers after proceeding over a breakpoint on
31 x86 targets.
32
33 --
34
35 x86 linux GDB and SIGALRM (???)
36 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00803.html
37
38 I know there are problems with single stepping through signal
39 handlers. These problems were present in 4.18. They were just masked
40 because 4.18 failed to recognize signal handlers. Fixing it is not
41 easy, and will require changes to handle_inferior_event(), that I
42 prefer not to make before the 5.0 release.
43
44 Mark
45
46 --
47
48 Revised UDP support (was: Re: [Fwd: [patch] UDP transport support])
49 http://sourceware.cygnus.com/ml/gdb-patches/2000-04/msg00000.html
50
51 (Broken) support for GDB's remote protocol across UDP is to be
52 included in the follow-on release.
53
54 --
55
56 Can't build IRIX -> arm GDB.
57 http://sourceware.cygnus.com/ml/gdb-patches/2000-04/msg00356.html
58
59 David Whedon writes:
60 > Now I'm building for an embedded arm target. If there is a way of turning
61 > remote-rdi off, I couldn't find it. It looks like it gets built by default
62 > in gdb/configure.tgt(line 58) Anyway, the build dies in
63 > gdb/rdi-share/unixcomm.c. SERPORT1 et. al. never get defined because we
64 > aren't one of the architectures supported.
65
66 --
67
68 Problem with weak functions
69 http://sourceware.cygnus.com/ml/gdb/2000-05/msg00060.html
70
71 Dan Nicolaescu writes:
72 > It seems that gdb-4.95.1 does not display correctly the function when
73 > stoping in weak functions.
74 >
75 > It stops in a function that is defined as weak, not in the function
76 > that is actualy run...
77
78 --
79
80 GDB 5.0 doesn't work on Linux/SPARC
81
82 --
83
84 Code Cleanups: Next Release
85 ===========================
86
87 The following are small cleanups that will hopefully be completed by
88 the follow on to 5.0.
89
90 --
91
92 Delete macro TARGET_BYTE_ORDER_SELECTABLE.
93
94 Patches in the database.
95
96 --
97
98 Purge PARAMS.
99
100 Eliminate all uses of PARAMS in GDB's source code.
101
102 --
103
104 Fix copyright notices.
105
106 Turns out that ``1998-2000'' isn't considered valid :-(
107
108 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00467.html
109
110 --
111
112 Find something better than DEFAULT_BFD_ARCH, DEFAULT_BFD_VEC to
113 determine the default isa/byte-order.
114
115 --
116
117 Rely on BFD_BIG_ENDIAN and BFD_LITTLE_ENDIAN instead of host dependant
118 BIG_ENDIAN and LITTLE_ENDIAN.
119
120 --
121
122 Code Cleanups: General
123 ======================
124
125 The following are more general cleanups and fixes. They are not tied
126 to any specific release.
127
128 --
129
130 Eliminate more compiler warnings.
131
132 Of course there also needs to be the usual debate over which warnings
133 are valid and how to best go about this.
134
135 One method: choose a single option; get agreement that it is
136 reasonable; try it out to see if there isn't anything silly about it
137 (-Wunused-parameters is an example of that) then incrementally hack
138 away.
139
140 The other method is to enable all warnings and eliminate them from one
141 file at a time.
142
143 --
144
145 Elimination of ``(catch_errors_ftype *) func''.
146
147 Like make_cleanup_func it isn't portable.
148 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00791.html
149 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00814.html
150
151
152 --
153
154 Nuke USG define.
155
156 --
157
158 [PATCH/5] src/intl/Makefile.in:distclean additions
159 http://sourceware.cygnus.com/ml/gdb-patches/2000-04/msg00363.html
160
161 Do not forget to merge the patch back into the trunk.
162
163 --
164
165 Rationalize the host-endian code (grep for HOST_BYTE_ORDER).
166
167 At present defs.h includes <endian.h> (which is linux specific) yet
168 almost nothing depends on it. Suggest "gdb_endian.h" which can also
169 handle <machine/endian.h> and only include that where it is really
170 needed.
171
172 --
173
174 Replace asprintf() calls with xasprintf() calls.
175
176 As with things like strdup() most calls to asprintf() don't check the
177 return value.
178
179 --
180
181 Replace strsave() + mstrsave() with libiberty:xstrdup().
182
183 --
184
185 Replace savestring() with something from libiberty.
186
187 An xstrldup()? but that would have different semantics.
188
189 --
190
191 Rationalize use of floatformat_unknown in GDB sources.
192
193 Instead of defaulting to floatformat_unknown, should hosts/targets
194 specify the value explicitly?
195
196 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00447.html
197
198 --
199
200 Add a ``name'' member to include/floatformat.h:struct floatformat.
201 Print that name in gdbarch.c.
202
203 --
204
205 Sort out the harris mess in include/floatformat.h (it hardwires two
206 different floating point formats).
207
208 --
209
210 See of the GDB local floatformat_do_doublest() and libiberty's
211 floatformat_to_double (which was once GDB's ...) can be merged some
212 how.
213
214 --
215
216 Eliminate mmalloc() from GDB.
217
218 Also eliminate it from defs.h.
219
220 --
221
222 Eliminate PTR. ISO-C allows ``void *''.
223
224 --
225
226 Eliminate abort ().
227
228 GDB should never abort. GDB should either throw ``error ()'' or
229 ``internal_error ()''. Better still GDB should naturally unwind with
230 an error status.
231
232 --
233
234 GDB probably doesn't build on FreeBSD pre 2.2.x
235 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00378.html
236
237 Fixes to get FreeBSD working on 2.2.x, 3.x and 4.x caused the code to
238 suffer bit rot.
239
240 --
241
242 Updated readline
243
244 Readline 4.? is out. A merge wouldn't hurt. Patches are in:
245
246 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00436.html
247
248 --
249
250 Deprecate "fg". Apparently ``fg'' is actually continue.
251
252 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00417.html
253
254 --
255
256 Deprecate current use of ``floatformat_unknown''.
257
258 Require all targets to explicitly provide their float format instead
259 of defaulting to floatformat unknown. Doing the latter leads to nasty
260 bugs.
261
262 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00447.html
263
264 --
265
266 Rationalize floatformat_to_double() vs floatformat_to_doublest().
267
268 Looks like GDB migrated floatformat_to_double() to libiberty but then
269 turned around and created a ..._to_doublest() the latter containing
270 several bug fixes.
271
272 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00472.html
273
274 --
275
276 Move floatformat_ia64_ext to libiberty/include floatformat.[ch].
277
278 http://sourceware.cygnus.com/ml/gdb-patches/2000-05/msg00466.html
279
280 --
281
282 Follow through `make check' with --enable-shared.
283
284 When the srcware tree is configured with --enable-shared, the `expect'
285 program won't run properly. Jim Wilson found out gdb has a local hack
286 to set LD_LIBRARY_PATH, but, AFAIK, no other project has been hacked
287 similarly.
288
289 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00845.html
290
291 --
292
293 The ``maintenance deprecate set endian big'' command doesn't notice
294 that it is deprecating ``set endian'' and not ``set endian big'' (big
295 is implemented using an enum). Is anyone going to notice this?
296
297 --
298
299 When tab expanding something like ``set arch<tab>'' ignore the
300 deprecated ``set archdebug'' and expand to ``set architecture''.
301
302 --
303
304 Eliminate ``arm_register_names[j] = (char *) regnames[j]'' and the
305 like from arm-tdep.c.
306
307 --
308
309 Fix uses of ->function.cfunc = set_function().
310
311 The command.c code calls sfunc() when a set command. Rather than
312 change it suggest fixing the callback function so that it is more
313 useful. See:
314
315 http://sourceware.cygnus.com/ml/gdb-patches/2000-06/msg00062.html
316
317 See also ``Fix implementation of ``target xxx''.'' below.
318
319 --
320
321 IRIX 3.x support is probably broken.
322
323 --
324
325 New Features and Fixes
326 ======================
327
328 These are harder than cleanups but easier than work involving
329 fundamental architectural change.
330
331 --
332
333 Add built-by, build-date, tm, xm, nm and anything else into gdb binary
334 so that you can see how the GDB was created.
335
336 Some of these (*m.h) would be added to the generated config.h. That
337 in turn would fix a long standing bug where by the build process many
338 not notice a changed tm.h file. Since everything depends on config.h,
339 a change to *m.h forces a change to config.h and, consequently forces
340 a rebuild.
341
342 --
343
344 Add an "info bfd" command that displays supported object formats,
345 similarly to objdump -i.
346
347 Is there a command already?
348
349 --
350
351 Fix ``I'm sorry, Dave, I can't do that.'' from symfile.c.
352
353 This requires internationalization.
354
355 --
356
357 Convert GDB build process to AUTOMAKE.
358
359 See also sub-directory configure below.
360
361 The current convention is (kind of) to use $(<header>_h) in all
362 dependency lists. It isn't done in a consistent way.
363
364 --
365
366 Cleanup configury support for optional sub-directories.
367
368 Check how GCC handles multiple front ends for an example of how things
369 could work. A tentative first step is to rationalize things so that
370 all sub directories are handled in a fashion similar to gdb/mi.
371
372 See also automake above.
373
374 --
375
376 Restructure gdb directory tree so that it avoids any 8.3 and 14
377 filename problems.
378
379 --
380
381 Add a transcript mechanism to GDB.
382
383 Such a mechanism might log all gdb input and output to a file in a
384 form that would allow it to be replayed. It could involve ``gdb
385 --transcript=FILE'' or it could involve ``(gdb) transcript file''.
386
387 --
388
389 Can the xdep files be replaced by autoconf?
390
391 --
392
393 Document trace machinery
394
395 --
396
397 Document ui-out and ui-file.
398
399 http://sourceware.cygnus.com/ml/gdb/2000-04/msg00121.html
400
401 --
402
403 Update texinfo.tex to latest?
404
405
406
407 --
408
409 Incorporate agentexpr.texi into gdb.texinfo
410
411 agentexpr.texi mostly describes the details of the byte code used for
412 tracepoints, not the internals of the support for this in GDB. So it
413 looks like gdb.texinfo is a better place for this information.
414
415 http://sourceware.cygnus.com/ml/gdb-patches/2000-04/msg00566.html
416
417 --
418
419 Document overlay machinery.
420
421 --
422
423 ``(gdb) catch signal SIGNAL''
424
425 Overlaps with ``handle SIGNAL'' but the implied behavour is different.
426 You can attach commands to a catch but not a handle. A handle has a
427 limited number of hardwired actions.
428
429 --
430
431 Get the TUI working on all platforms.
432
433 --
434
435 Add support for ``gdb --- PROGRAM ARGS ...''.
436 Add support for ``gdb -cmd=...''
437
438 Along with many variations. Check:
439
440 ????? for a full discussion.
441
442 for a discussion.
443
444 --
445
446 Implement ``(gdb) !ls''.
447
448 Which is very different from ``(gdb) ! ls''. Implementing the latter
449 is trivial.
450
451 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00034.html
452
453 --
454
455 Change the (char *list[]) to (const char (*)[]) so that dynamic lists can
456 be passed.
457
458 --
459
460 When tab expanding something like ``set arch<tab>'' ignore the
461 deprecated ``set archdebug'' and expand to ``set architecture''.
462
463 --
464
465 Replace the code that uses the host FPU with an emulator of the target
466 FPU.
467
468 --
469
470 Thread Support
471 ==============
472
473 --
474
475 Generic: lin-thread cannot handle thread exit (Mark Kettenis, Michael
476 Snyder) http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00525.html
477
478 The thread_db assisted debugging code doesn't handle exiting threads
479 properly, at least in combination with glibc 2.1.3 (the framework is
480 there, just not the actual code). There are at least two problems
481 that prevent this from working.
482
483 As an additional reference point, the pre thread_db code did not work
484 either.
485
486 --
487
488 GNU/Linux/x86 and random thread signals (and Solaris/SPARC but not
489 Solaris/x86).
490 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00336.html
491
492 Christopher Blizzard writes:
493
494 So, I've done some more digging into this and it looks like Jim
495 Kingdon has reported this problem in the past:
496
497 http://sourceware.cygnus.com/ml/bug-gdb/1999-10/msg00058.html
498
499 I can reproduce this problem both with and without Tom's patch. Has
500 anyone seen this before? Maybe have a solution for it hanging around?
501 :)
502
503 There's a test case for this documented at:
504
505 when debugging threaded applications you get extra SIGTRAPs
506 http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=9565
507
508 [There should be a GDB testcase - cagney]
509
510 --
511
512 GDB5 TOT on unixware 7
513 http://sourceware.cygnus.com/ml/gdb/2000-04/msg00119.html
514
515 Robert Lipe writes:
516 > I just spun the top of tree of the GDB5 branch on UnixWare 7. As a
517 > practical matter, the current thread support is somewhat more annoying
518 > than when GDB was thread-unaware.
519
520 --
521
522 Migrate qfThreadInfo packet -> qThreadInfo. (Andrew Cagney)
523
524 Add support for packet enable/disable commands with these thread
525 packets. General cleanup.
526
527 [PATCH] Document the ThreadInfo remote protocol queries
528 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00832.html
529
530 [PATCH] "info threads" queries for remote.c
531 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00831.html
532
533 --
534
535 Language Support
536 ================
537
538 New languages come onto the scene all the time.
539
540 --
541
542 Pascal (Pierre Muller, David Taylor)
543
544 Pierre Muller has contributed patches for adding Pascal Language
545 support to GDB.
546
547 2 pascal language patches inserted in database
548 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00521.html
549
550 Indent -gnu ?
551 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00496.html
552
553 --
554
555 Java (Anthony Green, David Taylor)
556
557 Anthony Green has a number of Java patches that did not make it into
558 the 5.0 release.
559
560 Patch: java tests
561 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00512.html
562
563 Patch: java booleans
564 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00515.html
565
566 Patch: handle N_MAIN stab
567 http://sourceware.cygnus.com/ml/gdb-patches/2000-q1/msg00527.html
568
569 --
570
571 [Comming...]
572
573 Modify gdb to work correctly with Pascal.
574
575 --
576
577 Re: Various C++ things
578
579 value_headof/value_from_vtable_info are worthless, and should be
580 removed. The one place in printcmd.c that uses it should use the RTTI
581 functions.
582
583 RTTI for g++ should be using the typeinfo functions rather than the
584 vtables. The typeinfo functions are always at offset 4 from the
585 beginning of the vtable, and are always right. The vtables will have
586 weird names like E::VB sometimes. The typeinfo function will always
587 be "E type_info function", or somesuch.
588
589 value_virtual_fn_field needs to be fixed so there are no failures for
590 virtual functions for C++ using g++.
591
592 Testsuite cases are the major priority right now for C++ support,
593 since i have to make a lot of changes that could potentially break
594 each other.
595
596 --
597
598 Add support for Modula3
599
600 Get DEC/Compaq to contribute their Modula-3 support.
601
602 --
603
604 Remote Protocol Support
605 =======================
606
607 --
608
609 set/show remote X-packet ...
610
611 ``(gdb) help set remote X-packet'' doesn't list the applicable
612 responses. The help message needs to be expanded.
613
614 --
615
616 Remote protocol doco feedback.
617
618 Too much feedback to mention needs to be merged in (901660). Search
619 for the word ``remote''.
620
621
622 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00023.html
623 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00056.html
624 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00382.html
625
626 --
627
628 GDB doesn't recover gracefully from remote protocol errors.
629
630 GDB wasn't checking for NAKs from the remote target. Instead a NAK is
631 ignored and a timeout is required before GDB retries. A pre-cursor to
632 fixing this this is making GDB's remote protocol packet more robust.
633
634 While downloading to a remote protocol target, gdb ignores packet
635 errors in so far as it will continue to edownload with chunk N+1 even
636 if chunk N was not correctly sent. This causes gdb.base/remote.exp to
637 take a painfully long time to run. As a PS that test needs to be
638 fixed so that it builds on 16 bit machines.
639
640 --
641
642 Add the cycle step command.
643
644 http://sourceware.cygnus.com/ml/gdb/2000-q1/msg00237.html
645
646 --
647
648 Resolve how to scale things to support very large packets.
649
650 --
651
652 Resolve how to handle a target that changes things like its endianess
653 on the fly - should it be returned in the ``T'' packet?
654
655 Underlying problem is that the register file is target endian. If the
656 target endianess changes gdb doesn't know.
657
658 --
659
660 Symbol Support
661 ==============
662
663 If / when GDB starts to support the debugging of multi-processor
664 (rather than multi-thread) applications the symtab code will need to
665 be updated a little so that several independant symbol tables are
666 active at a given time.
667
668 The other interesting change is a clarification of the exact meaning
669 of CORE_ADDR and that has had consequences for a few targets (that
670 were abusing that data type).
671
672 --
673
674 Investiagate ways of reducing memory.
675
676 --
677
678 Investigate ways of improving load time.
679
680 --
681
682 Get the d10v to use POINTER_TO_ADDRESS and ADDRESS_TO_POINTER.
683
684 Consequence of recent symtab clarification. No marks for figuring out
685 who maintains the d10v.
686
687 --
688
689 Get the MIPS to correctly sign extend all address <-> pointer
690 conversions.
691
692 Consequence of recent symtab clarification. No marks for figuring out
693 who maintains the MIPS.
694
695 --
696
697 Testsuite Support
698 =================
699
700 There are never to many testcases.
701
702 --
703
704 Better thread testsuite.
705
706 --
707
708 Better C++ testsuite.
709
710 --
711
712 Look at adding a GDB specific testsuite directory so that white box
713 tests of key internals can be added (eg ui_file).
714
715 --
716
717 Separate out tests that involve the floating point (FP).
718
719 (Something for people brining up new targets). FP and non-fp tests
720 are combined. I think there should be set of basic tests that
721 exercise pure integer support and then a more expanded set that
722 exercise FP and FP/integer interactions.
723
724 As an example, the MIPS, for n32 as problems with passing FP's and
725 structs. Since most inferior call tests include FP it is difficult to
726 determine of the integer tests are ok.
727
728 --
729
730 Architectural Changes: General
731 ==============================
732
733 These are harder than simple cleanups / fixes and, consequently
734 involve more work. Typically an Architectural Change will be broken
735 down into a more digestible set of cleanups and fixes.
736
737 --
738
739 Cleanup software single step.
740
741 At present many targets implement software single step by directly
742 blatting memory (see rs6000-tdep.c). Those targets should register
743 the applicable breakpoints using the breakpoint framework. Perhaphs a
744 new internal breakpoint class ``step'' is needed.
745
746 --
747
748 Replace READ_FP() with FRAME_HANDLE().
749
750 READ_FP() is a hangover from the days of the vax when the ABI really
751 did have a frame pointer register. Modern architectures typically
752 construct a virtual frame-handle from the stack pointer and various
753 other bits of string.
754
755 Unfortunatly GDB still treats this synthetic FP register as though it
756 is real. That in turn really confuses users (arm and ``print $fp'' VS
757 ``info registers fp''). The synthetic FP should be separated out of
758 the true register set presented to the user.
759
760 --
761
762 Register Cache Cleanup (below from Andrew Cagney)
763
764 I would depict the current register architecture as something like:
765
766 High GDB --> Low GDB
767 | |
768 \|/ \|/
769 --- REG NR -----
770 |
771 register + REGISTER_BYTE(reg_nr)
772 |
773 \|/
774 -------------------------
775 | extern register[] |
776 -------------------------
777
778 where neither the high (valops.c et.al.) or low gdb (*-tdep.c) are
779 really clear on what mechanisms they should be using to manipulate that
780 buffer. Further, much code assumes, dangerously, that registers are
781 contigious. Having got mips-tdep.c to support multiple ABIs, believe
782 me, that is a bad assumption. Finally, that register cache layout is
783 determined by the current remote/local target and _not_ the less
784 specific target ISA. In fact, in many cases it is determined by the
785 somewhat arbitrary layout of the [gG] packets!
786
787
788 How I would like the register file to work is more like:
789
790
791 High GDB
792 |
793 \|/
794 pseudo reg-nr
795 |
796 map pseudo <->
797 random cache
798 bytes
799 |
800 \|/
801 ------------
802 | register |
803 | cache |
804 ------------
805 /|\
806 |
807 map random cache
808 bytes to target
809 dependant i-face
810 /|\
811 |
812 target dependant
813 such as [gG] packet
814 or ptrace buffer
815
816 The main objectives being:
817
818 o a clear separation between the low
819 level target and the high level GDB
820
821 o a mechanism that solves the general
822 problem of register aliases, overlaps
823 etc instead of treating them as optional
824 extras that can be wedged in as an after
825 thought (that is a reasonable description
826 of the current code).
827
828 Identify then solve the hard case and the
829 rest just falls out. GDB solved the easy
830 case and then tried to ignore the real
831 world :-)
832
833 o a removal of the assumption that the
834 mapping between the register cache
835 and virtual registers is largely static.
836 If you flip the USR/SSR stack register
837 select bit in the status-register then
838 the corresponding stack registers should
839 reflect the change.
840
841 o a mechanism that clearly separates the
842 gdb internal register cache from any
843 target (not architecture) dependant
844 specifics such as [gG] packets.
845
846 Of course, like anything, it sounds good in theory. In reality, it
847 would have to contend with many<->many relationships at both the
848 virt<->cache and cache<->target level. For instance:
849
850 virt<->cache
851 Modifying an mmx register may involve
852 scattering values across both FP and
853 mmpx specific parts of a buffer
854
855 cache<->target
856 When writing back a SP it may need to
857 both be written to both SP and USP.
858
859
860 Hmm,
861
862 Rather than let this like the last time it was discussed, just slip, I'm
863 first going to add this e-mail (+ references) to TODO. I'd then like to
864 sketch out a broad strategy I think could get us there.
865
866
867 First thing I'd suggest is separating out the ``extern registers[]''
868 code so that we can at least identify what is using it. At present
869 things are scattered across many files. That way we can at least
870 pretend that there is a cache instead of a global array :-)
871
872 I'd then suggest someone putting up a proposal for the pseudo-reg /
873 high-level side interface so that code can be adopted to it. For old
874 code, initially a blanket rename of write_register_bytes() to
875 deprecated_write_register_bytes() would help.
876
877 Following that would, finaly be the corresponding changes to the target.
878
879 --
880
881 Check that GDB can handle all BFD architectures (Andrew Cagney)
882
883 There should be a test that checks that BFD/GDB are in sync with
884 regard to architecture changes. Something like a test that first
885 queries GDB for all supported architectures and then feeds each back
886 to GDB.. Anyone interested in learning how to write tests? :-)
887
888 --
889
890 Architectural Change: Multi-arch et al.
891 =======================================
892
893 The long term objective is to remove all assumptions that there is a
894 single target with a single address space with a single instruction
895 set architecture and single application binary interface.
896
897 This is an ongoing effort. The first milestone is to enable
898 ``multi-arch'' where by all architectural decisions are made at
899 runtime.
900
901 It should be noted that ``gdbarch'' is really ``gdbabi'' and
902 ``gdbisa''. Once things are multi-arched breaking that down correctly
903 will become much easier.
904
905 --
906
907 GDBARCH cleanup (Andrew Cagney)
908
909 The non-generated parts of gdbarch.{sh,h,c} should be separated out
910 into arch-utils.[hc].
911
912 Document that gdbarch_init_ftype could easily fail because it didn't
913 identify an architecture.
914
915 --
916
917 Fix BELIEVE_PPC_PROMOTION. Change it to BELIEVE_PPC_PROMOTION_P?
918
919 At present there is still #ifdef BELIEVE_PPC_PROMOTION code in the
920 symtab file.
921
922 --
923
924 Fix target_signal_from_host() etc.
925
926 The name is wrong for starters. ``target_signal'' should probably be
927 ``gdb_signal''. ``from_host'' should be ``from_target_signal''.
928 After that it needs to be multi-arched and made independant of any
929 host signal numbering.
930
931 --
932
933 Update ALPHA so that it uses ``struct frame_extra_info'' instead of
934 EXTRA_FRAME_INFO.
935
936 This is a barrier to replacing mips_extra_func_info with something
937 that works with multi-arch.
938
939 --
940
941 Multi-arch mips_extra_func_info.
942
943 This first needs the alpha to be updated so that it uses ``struct
944 frame_extra_info''.
945
946 --
947
948 Rationalize TARGET_SINGLE_FORMAT and TARGET_SINGLE_BIT et al.
949
950 Surely one of them is redundant.
951
952 --
953
954 Convert ALL architectures to MULTI-ARCH.
955
956 --
957
958 Select the initial multi-arch ISA / ABI based on --target or similar.
959
960 At present the default is based on what ever is first in the BFD
961 archures table. It should be determined based on the ``--target=...''
962 name.
963
964 --
965
966 Make MIPS pure multi-arch.
967
968 It is only at the multi-arch enabled stage.
969
970 --
971
972 Truly multi-arch.
973
974 Enable the code to recognize --enable-targets=.... like BINUTILS does.
975
976 Can the tm.h and nm.h files be eliminated by multi-arch.
977
978 --
979
980 Architectural Change: MI, LIBGDB and scripting languages
981 ========================================================
982
983 See also architectural changes related to the event loop. LIBGDB
984 can't be finished until there is a generic event loop being used by
985 all targets.
986
987 The long term objective is it to be possible to integrate GDB into
988 scripting languages.
989
990 --
991
992 Implement generic ``(gdb) commmand > file''
993
994 Once everything is going through ui_file it should be come fairly
995 easy.
996
997 http://sourceware.cygnus.com/ml/gdb/2000-04/msg00104.html
998
999 --
1000
1001 Replace gdb_stdtarg with gdb_targout (and possibly gdb_targerr).
1002
1003 gdb_stdtarg is easily confused with gdb_stdarg.
1004
1005 --
1006
1007 Extra ui_file methods - dump.
1008
1009 Very useful for whitebox testing.
1010
1011 --
1012
1013 Eliminate error_begin().
1014
1015 With ui_file, there is no need for the statefull error_begin ()
1016 function.
1017
1018 --
1019
1020 Send normal output to gdb_stdout.
1021 Send error messages to gdb_stderror.
1022 Send debug and log output log gdb_stdlog.
1023
1024 GDB still contains many cases where (f)printf or printf_filtered () is
1025 used when it should be sending the messages to gdb_stderror or
1026 gdb_stdlog. The thought of #defining printf to something has crossed
1027 peoples minds ;-)
1028
1029 --
1030
1031 Re-do GDB's output pager.
1032
1033 GDB's output pager still relies on people correctly using *_filtered
1034 for gdb_stdout and *_unfiltered for gdb_stdlog / gdb_stderr.
1035 Hopefully, with all normal output going to gdb_stdout, the pager can
1036 just look at the ui_file that the output is on and then use that to
1037 decide what to do about paging. Sounds good in theory.
1038
1039 --
1040
1041 Check/cleanup MI documentation.
1042
1043 The list of commands specified in the documentation needs to be
1044 checked against the mi-cmds.c table in a mechanical way (so that they
1045 two can be kept up-to-date).
1046
1047 --
1048
1049 Convert MI into libgdb
1050
1051 MI provides a text interface into what should be many of the libgdb
1052 functions. The implementation of those functions should be separated
1053 into the MI interface and the functions proper. Those functions being
1054 moved to gdb/lib say.
1055
1056 --
1057
1058 Create libgdb.h
1059
1060 The first part can already be found in defs.h.
1061
1062 --
1063
1064 MI's input does not use buffering.
1065
1066 At present the MI interface reads raw characters of from an unbuffered
1067 FD. This is to avoid several nasty buffer/race conditions. That code
1068 should be changed so that it registers its self with the event loop
1069 (on the input FD) and then push commands up to MI as they arrive.
1070
1071 The serial code already does this.
1072
1073 --
1074
1075 Make MI interface accessable from existing CLI.
1076
1077 --
1078
1079 Add a breakpoint-edit command to MI.
1080
1081 It would be similar to MI's breakpoint create but would apply to an
1082 existing breakpoint. It saves the need to delete/create breakpoints
1083 when ever they are changed.
1084
1085 --
1086
1087 Add directory path to MI breakpoint.
1088
1089 That way the GUI's task of finding the file within which the
1090 breakpoint was set is simplified.
1091
1092 --
1093
1094 Add a mechanism to reject certain expression classes to MI
1095
1096 There are situtations where you don't want GDB's expression
1097 parser/evaluator to perform inferior function calls or variable
1098 assignments. A way of restricting the expression parser so that such
1099 operations are not accepted would be very helpful.
1100
1101 --
1102
1103 Remove sideffects from libgdb breakpoint create function.
1104
1105 The user can use the CLI to create a breakpoint with partial
1106 information - no file (gdb would use the file from the last
1107 breakpoint).
1108
1109 The libgdb interface currently affects that environment which can lead
1110 to confusion when a user is setting breakpoints via both the MI and
1111 the CLI.
1112
1113 This is also a good example of how getting the CLI ``right'' will be
1114 hard.
1115
1116 --
1117
1118 Move gdb_lasterr to ui_out?
1119
1120 The way GDB throws errors and records them needs a re-think. ui_out
1121 handles the correct output well. It doesn't resolve what to do with
1122 output / error-messages when things go wrong.
1123
1124 --
1125
1126 do_setshow_command contains a 1024 byte buffer.
1127
1128 The function assumes that there will never be any more than 1024 bytes
1129 of enum. It should use mem_file.
1130
1131 --
1132
1133 Should struct cmd_list_element . completer take the command as an
1134 argument?
1135
1136 --
1137
1138 Should the bulk of top.c:line_completion_function() be moved to
1139 command.[hc]? complete_on_cmdlist() and complete_on_enums() could
1140 then be made private.
1141
1142 --
1143
1144 top.c (execute_command): Should a command being valid when the target
1145 is running be made an attribute (predicate) to the command rather than
1146 an explicit set of tests.
1147
1148 --
1149
1150 top.c (execute_command): Should the bulk of this function be moved
1151 into command.[hc] so that top.c doesn't grub around in the command
1152 internals?
1153
1154 --
1155
1156 Architectural Change: Async
1157 ===========================
1158
1159 While GDB uses an event loop when prompting the user for input. That
1160 event loop is not exploited by targets when they allow the target
1161 program to continue. Typically targets still block in (target_wait())
1162 until the program again halts.
1163
1164 The closest a target comes to supporting full asynchronous mode are
1165 the remote targets ``async'' and ``extended-async''.
1166
1167 --
1168
1169 Asynchronous expression evaluator
1170
1171 Inferior function calls hang GDB.
1172
1173 --
1174
1175 Fix implementation of ``target xxx''.
1176
1177 At present when the user specifies ``target xxxx'', the CLI maps that
1178 directly onto a target open method. It is then assumed that the
1179 target open method should do all sorts of complicated things as this
1180 is the only chance it has. Check how the various remote targets
1181 duplicate the target operations. Check also how the various targets
1182 behave differently for purely arbitrary reasons.
1183
1184 What should happen is that ``target xxxx'' should call a generic
1185 ``target'' function and that should then co-ordinate the opening of
1186 ``xxxx''. This becomes especially important when you're trying to
1187 open an asynchronous target that may need to perform background tasks
1188 as part of the ``attach'' phase.
1189
1190 Unfortunatly, due to limitations in the old/creaking command.h
1191 interface, that isn't possible. The function being called isn't told
1192 of the ``xxx'' or any other context information.
1193
1194 Consequently a precursor to fixing ``target xxxx'' is to clean up the
1195 CLI code so that it passes to the callback function (attatched to a
1196 command) useful information such as the actual command and a context
1197 for that command. Other changes such as making ``struct command''
1198 opaque may also help.
1199
1200 See also:
1201 http://sourceware.cygnus.com/ml/gdb-patches/2000-06/msg00062.html
1202
1203 --
1204
1205 Make "target xxx" command interruptible.
1206
1207 As things become async this becomes possible. A target would start
1208 the connect and then return control to the event loop. A cntrl-c
1209 would notify the target that the operation is to be abandoned and the
1210 target code could respond.
1211
1212 --
1213
1214 Add a "suspend" subcommand of the "continue" command to suspend gdb
1215 while continuing execution of the subprocess. Useful when you are
1216 debugging servers and you want to dodge out and initiate a connection
1217 to a server running under gdb.
1218
1219 [hey async!!]
1220
1221 --
1222
1223 TODO FAQ
1224 ========
1225
1226 Frequently requested but not approved requests.
1227
1228 --
1229
1230 Eliminate unused argument warnings using ATTRIBUTE_UNUSED.
1231
1232 The benefits on this one are thought to be marginal - GDBs design
1233 means that unused parameters are very common. GCC 3.0 will also
1234 include the option -Wno-unused-parameter which means that ``-Wall
1235 -Wno-unused-parameters -Werror'' can be specified.
1236
1237 --
1238
1239
1240
1241 Legacy Wish List
1242 ================
1243
1244 This list is not up to date, and opinions vary about the importance or
1245 even desirability of some of the items. If you do fix something, it
1246 always pays to check the below.
1247
1248 --
1249
1250 @c This does not work (yet if ever). FIXME.
1251 @c @item --parse=@var{lang} @dots{}
1252 @c Configure the @value{GDBN} expression parser to parse the listed languages.
1253 @c @samp{all} configures @value{GDBN} for all supported languages. To get a
1254 @c list of all supported languages, omit the argument. Without this
1255 @c option, @value{GDBN} is configured to parse all supported languages.
1256
1257 --
1258
1259 START_INFERIOR_TRAPS_EXPECTED need never be defined to 2, since that
1260 is its default value. Clean this up.
1261
1262 --
1263
1264 It should be possible to use symbols from shared libraries before we know
1265 exactly where the libraries will be loaded. E.g. "b perror" before running
1266 the program. This could maybe be done as an extension of the "breakpoint
1267 re-evaluation" after new symbols are loaded.
1268
1269 --
1270
1271 Make single_step() insert and remove breakpoints in one operation.
1272
1273 [If this is talking about having single_step() insert the breakpoints,
1274 run the target then pull the breakpoints then it is wrong. The
1275 function has to return as control has to eventually be passed back to
1276 the main event loop.]
1277
1278 --
1279
1280 Speed up single stepping by avoiding extraneous ptrace calls.
1281
1282 --
1283
1284 Speed up single stepping by not inserting and removing breakpoints
1285 each time the inferior starts and stops.
1286
1287 Breakpoints should not be inserted and deleted all the time. Only the
1288 one(s) there should be removed when we have to step over one. Support
1289 breakpoints that don't have to be removed to step over them.
1290
1291 [this has resulted in numerous debates. The issue isn't clear cut]
1292
1293 --
1294
1295 Provide "voodoo" debugging of core files. This creates a zombie
1296 process as a child of the debugger, and loads it up with the data,
1297 stack, and regs of the core file. This allows you to call functions
1298 in the executable, to manipulate the data in the core file.
1299
1300 [you wish]
1301
1302 --
1303
1304 GDB reopens the source file on every line, as you "next" through it.
1305
1306 [still true? I've a memory of this being fixed]
1307
1308 --
1309
1310 Perhaps "i source" should take an argument like that of "list".
1311
1312 --
1313
1314 Remove "at 0xnnnn" from the "b foo" response, if `print address off' and if
1315 it matches the source line indicated.
1316
1317 --
1318
1319 The prompt at end of screen should accept space as well as CR.
1320
1321 --
1322
1323 Backtrace should point out what the currently selected frame is, in
1324 its display, perhaps showing "@3 foo (bar, ...)" or ">3 foo (bar,
1325 ...)" rather than "#3 foo (bar, ...)".
1326
1327 --
1328
1329 "i program" should work for core files, and display more info, like what
1330 actually caused it to die.
1331
1332 --
1333
1334 "x/10i" should shorten the long name, if any, on subsequent lines.
1335
1336 --
1337
1338 "next" over a function that longjumps, never stops until next time you happen
1339 to get to that spot by accident. E.g. "n" over execute_command which has
1340 an error.
1341
1342 --
1343
1344 "set zeroprint off", don't bother printing members of structs which
1345 are entirely zero. Useful for those big structs with few useful
1346 members.
1347
1348 --
1349
1350 GDB does four ioctl's for every command, probably switching terminal modes
1351 to/from inferior or for readline or something.
1352
1353 --
1354
1355 terminal_ours versus terminal_inferior: cache state. Switch should be a noop
1356 if the state is the same, too.
1357
1358 --
1359
1360 "i frame" shows wrong "arglist at" location, doesn't show where the args
1361 should be found, only their actual values.
1362
1363 --
1364
1365 There should be a way for "set" commands to validate the new setting
1366 before it takes effect.
1367
1368 --
1369
1370 "ena d" is ambiguous, why? "ena delete" seems to think it is a command!
1371
1372 --
1373
1374 i line VAR produces "Line number not known for symbol ``var''.". I
1375 thought we were stashing that info now!
1376
1377 --
1378
1379 We should be able to write to random files at hex offsets like adb.
1380
1381 --
1382
1383 [elena - delete this]
1384
1385 Handle add_file with separate text, data, and bss addresses. Maybe
1386 handle separate addresses for each segment in the object file?
1387
1388 --
1389
1390 [Jimb/Elena delete this one]
1391
1392 Handle free_named_symtab to cope with multiply-loaded object files
1393 in a dynamic linking environment. Should remember the last copy loaded,
1394 but not get too snowed if it finds references to the older copy.
1395
1396 --
1397
1398 [elena delete this also]
1399
1400 Remove all references to:
1401 text_offset
1402 data_offset
1403 text_data_start
1404 text_end
1405 exec_data_offset
1406 ...
1407 now that we have BFD. All remaining are in machine dependent files.
1408
1409 --
1410
1411 Re-organize help categories into things that tend to fit on a screen
1412 and hang together.
1413
1414 --
1415
1416 Add in commands like ADB's for searching for patterns, etc. We should
1417 be able to examine and patch raw unsymboled binaries as well in gdb as
1418 we can in adb. (E.g. increase the timeout in /bin/login without source).
1419
1420 [actually, add ADB interface :-]
1421
1422 --
1423
1424 When doing "step" or "next", if a few lines of source are skipped between
1425 the previous line and the current one, print those lines, not just the
1426 last line of a multiline statement.
1427
1428 --
1429
1430 Handling of "&" address-of operator needs some serious overhaul
1431 for ANSI C and consistency on arrays and functions.
1432 For "float point[15];":
1433 ptype &point[4] ==> Attempt to take address of non-lvalue.
1434 For "char *malloc();":
1435 ptype malloc ==> "char *()"; should be same as
1436 ptype &malloc ==> "char *(*)()"
1437 call printf ("%x\n", malloc) ==> weird value, should be same as
1438 call printf ("%x\n", &malloc) ==> correct value
1439
1440 --
1441
1442 Fix dbxread.c symbol reading in the presence of interrupts. It
1443 currently leaves a cleanup to blow away the entire symbol table when a
1444 QUIT occurs. (What's wrong with that? -kingdon, 28 Oct 1993).
1445
1446 [I suspect that the grype was that, on a slow system, you might want
1447 to cntrl-c and get just half the symbols and then load the rest later
1448 - scary to be honest]
1449
1450 --
1451
1452 Mipsread.c reads include files depth-first, because the dependencies
1453 in the psymtabs are way too inclusive (it seems to me). Figure out what
1454 really depends on what, to avoid recursing 20 or 30 times while reading
1455 real symtabs.
1456
1457 --
1458
1459 value_add() should be subtracting the lower bound of arrays, if known,
1460 and possibly checking against the upper bound for error reporting.
1461
1462 --
1463
1464 When listing source lines, check for a preceding \n, to verify that
1465 the file hasn't changed out from under us.
1466
1467 [fixed by some other means I think. That hack wouldn't actually work
1468 reliably - the file might move such that another \n appears. ]
1469
1470 --
1471
1472 Get all the remote systems (where the protocol allows it) to be able to
1473 stop the remote system when the GDB user types ^C (like remote.c
1474 does). For ebmon, use ^Ak.
1475
1476 --
1477
1478 Possible feature: A version of the "disassemble" command which shows
1479 both source and assembly code ("set symbol-filename on" is a partial
1480 solution).
1481
1482 [has this been done? It was certainly done for MI and GDBtk]
1483
1484 --
1485
1486 investigate "x/s 0" (right now stops early) (I think maybe GDB is
1487 using a 0 address for bad purposes internally).
1488
1489 --
1490
1491 Make "info path" and path_command work again (but independent of the
1492 environment either of gdb or that we'll pass to the inferior).
1493
1494 --
1495
1496 Make GDB understand the GCC feature for putting octal constants in
1497 enums. Make it so overflow on an enum constant does not error_type
1498 the whole type. Allow arbitrarily large enums with type attributes.
1499 Put all this stuff in the testsuite.
1500
1501 --
1502
1503 Make TYPE_CODE_ERROR with a non-zero TYPE_LENGTH more useful (print
1504 the value in hex; process type attributes). Add this to the
1505 testsuite. This way future compilers can add new types and old
1506 versions of GDB can do something halfway reasonable.
1507
1508 --
1509
1510 Fix mdebugread.c:parse_type to do fundamental types right (see
1511 rs6000_builtin_type in stabsread.c for what "right" is--the point is
1512 that the debug format fixes the sizes of these things and it shouldn't
1513 depend on stuff like TARGET_PTR_BIT and so on. For mdebug, there seem
1514 to be separate bt* codes for 64 bit and 32 bit things, and GDB should
1515 be aware of that). Also use a switch statement for clarity and speed.
1516
1517 --
1518
1519 Investigate adding symbols in target_load--some targets do, some
1520 don't.
1521
1522 --
1523
1524 Put dirname in psymtabs and change lookup*symtab to use dirname (so
1525 /foo/bar.c works whether compiled by cc /foo/bar.c, or cd /foo; cc
1526 bar.c).
1527
1528 --
1529
1530 Merge xcoffread.c and coffread.c. Use breakpoint_re_set instead of
1531 fixup_breakpoints.
1532
1533 --
1534
1535 Make a watchpoint which contains a function call an error (it is
1536 broken now, making it work is probably not worth the effort).
1537
1538 --
1539
1540 New test case based on weird.exp but in which type numbers are not
1541 renumbered (thus multiply defining a type). This currently causes an
1542 infinite loop on "p v_comb".
1543
1544 --
1545
1546 [Hey! Hint Hint Delete Delete!!!]
1547
1548 Fix 386 floating point so that floating point registers are real
1549 registers (but code can deal at run-time if they are missing, like
1550 mips and 68k). This would clean up "info float" and related stuff.
1551
1552 --
1553
1554 gcc -g -c enummask.c then gdb enummask.o, then "p v". GDB complains
1555 about not being able to access memory location 0.
1556
1557 -------------------- enummask.c
1558 enum mask
1559 {
1560 ANIMAL = 0,
1561 VEGETABLE = 1,
1562 MINERAL = 2,
1563 BASIC_CATEGORY = 3,
1564
1565 WHITE = 0,
1566 BLUE = 4,
1567 GREEN = 8,
1568 BLACK = 0xc,
1569 COLOR = 0xc,
1570
1571 ALIVE = 0x10,
1572
1573 LARGE = 0x20
1574 } v;
1575
1576 --
1577
1578 If try to modify value in file with "set write off" should give
1579 appropriate error not "cannot access memory at address 0x65e0".
1580
1581 --
1582
1583 Allow core file without exec file on RS/6000.
1584
1585 --
1586
1587 Make sure "shell" with no arguments works right on DOS.
1588
1589 --
1590
1591 Make gdb.ini (as well as .gdbinit) be checked on all platforms, so
1592 the same directory can be NFS-mounted on unix or DOS, and work the
1593 same way.
1594
1595 --
1596
1597 [Is this another delete???]
1598
1599 Get SECT_OFF_TEXT stuff out of objfile_relocate (might be needed to
1600 get RS/6000 to work right, might not be immediately relevant).
1601
1602 --
1603
1604 Work out some kind of way to allow running the inferior to be done as
1605 a sub-execution of, eg. breakpoint command lists. Currently running
1606 the inferior interupts any command list execution. This would require
1607 some rewriting of wait_for_inferior & friends, and hence should
1608 probably be done in concert with the above.
1609
1610 --
1611
1612 Add function arguments to gdb user defined functions.
1613
1614 --
1615
1616 Add convenience variables that refer to exec file, symbol file,
1617 selected frame source file, selected frame function, selected frame
1618 line number, etc.
1619
1620 --
1621
1622 Modify the handling of symbols grouped through BINCL/EINCL stabs to
1623 allocate a partial symtab for each BINCL/EINCL grouping. This will
1624 seriously decrease the size of inter-psymtab dependencies and hence
1625 lessen the amount that needs to be read in when a new source file is
1626 accessed.
1627
1628 --
1629
1630 Add a command for searching memory, a la adb. It specifies size,
1631 mask, value, start address. ADB searches until it finds it or hits
1632 an error (or is interrupted).
1633
1634 --
1635
1636 Remove the range and type checking code and documentation, if not
1637 going to implement.
1638
1639 # Local Variables:
1640 # mode: text
1641 # End: