+Contents
+--------
- gdb bug list
- John Gilmore, gnu@cygnus.com
+If you find inaccuracies in this list, please send mail to
+bug-gdb@prep.ai.mit.edu.
-This bug list is probably not up to date or accurate, but it reflects
-some known bugs in gdb, if you are into bug-hunting.
+* Things to do for Mach.
+* General to do list.
+Things to do for Mach
+---------------------
-Update the TODO list with all the lists of gdb bugs lying around on paper.
+This section is up to date as of 28 Oct 1993.
-"share" command should not need to be manually run. It should be run
-as soon as possible, automatically, both on "run" and on core files.
+All my attempted compilation was on douglas.gnu.ai.mit.edu.
+
+0. Get it to compile and run again, especially for non-threaded
+programs (some of the following are sub-tasks for this).
+
+1. attach_command still contains a call to wait_for_inferior which is
+wrong for Mach. Need to figure out a way to push this functionality
+into target_attach (perhaps by having target_attach, for non-Mach
+targets, call a function which does what is now in attach_command).
+
+2. jtv's port contains an #ifdef which skips the call to
+insert_step_breakpoint right after SOLIB_CREATE_INFERIOR_HOOK, but
+goes ahead and calls insert_breakpoints. I don't understand this--the
+comment would appear to apply to all breakpoints. Perhaps it is an
+artifact from a previous version of the Mach port? (BTW, the modern
+equivalent is the call to proceed from m3_create_inferior; proceed
+inserts breakpoints).
+
+3. Get the thread stuff to use the new generic thread code (enhancing
+the generic thread code to include any missing features). This is
+necessary to make thread-specific breakpoints work again. If someone
+wants to try to patch up the old Mach threads code, need to deal with
+the hooks for PREPARE_TO_PROCEED and ATTACH_TO_THREAD, which I haven't
+merged--can these go in target_resume()?
+
+4. BFD problem--"Undefined symbol _aout_32_swap_exec_header_in".
+Believed to be fixed (fix not yet tested with GDB).
+
+5. The linker complains about mfree and so on being multiply defined.
+Believed to be fixed (fix not yet tested).
+
+6. i386_mach3_float_info and register_addr were undefined in the
+link. I haven't investigated, but probably just another easy
+configuration thing or something.
+
+7. I couldn't find mach_port_t in any of the headers in
+/usr/include/*.h or /usr/include/mach/*.h (I think those are the two
+places I grepped; I don't know what headers I was actually getting).
+Typedeffing it to void * in nm-m3.h seemed to work, but of course
+that's hardly an elegant solution.
+
+8. Implement the features which CMU gdb has which the main GDB does
+not. This could be done by getting paperwork from CMU and merging
+their changes, or by reimplementing them.
+
+General To Do List
+------------------
+
+This to do list is probably not up to date, and opinions may vary
+about the importance or even desirability of some of the items.
It should be possible to use symbols from shared libraries before we know
exactly where the libraries will be loaded. E.g. "b perror" before running
Speed up single stepping by not inserting and removing breakpoints
each time the inferior starts and stops.
-Speed up watchpoints by not single-stepping them, but do something
-faster like single-line execution.
+Breakpoints should not be inserted and deleted all the time. Only the
+one(s) there should be removed when we have to step over one. Support
+breakpoints that don't have to be removed to step over them.
-Update gdb.texinfo to include doc on the directory structure and
+Speed up watchpoints by using debug registers, page table diddling (on
+SunOS4, can call mprotect() in the inferior; on other machines can do
+something simpler), etc. Note that you need to detect a
+"fast-watchable expression" (i.e., if watching "*p", then either a
+change to the address pointed to by p or a change to p itself which
+causes the value of *p to change, is a watchpoint hit). It is
+possible we will also someday want extensions which are
+lower-level--"read from these addresses", "write to these addresses",
+etc., but there is no consensus about just how important these are and
+exactly what form they would take. There is a consensus that the
+existing watchpoint semantics should use hardware assists when
+available.
+
+Update gdbint.texinfo to include doc on the directory structure and
the various tricks of building gdb.
Do a tutorial in gdb.texinfo on how to do simple things in gdb.
E.g. how to set a breakpoint that just prints something and continues.
How to break on aborts. Etc.
-Do a "new features" section for release 4.
-
Provide "voodoo" debugging of core files. This creates a zombie
process as a child of the debugger, and loads it up with the data,
stack, and regs of the core file. This allows you to call functions
Persistent command history: A feature where you could save off a list
of the commands you did, so you can edit it into something that will bring
-the target to the same place every time you source it. Sun wants it.
+the target to the same place every time you source it.
This would also be useful for automated fast watchpointing; if you go
past the place where it watchpoints, you just start it over again and
do it more carefully.
-Deal with the Sun ptrace bug that loses the registers if the stack is
-paged out.
+Deal with the SunOS 4.0 and 4.1.1 ptrace bug that loses the registers if
+the stack is paged out.
Finish the C++ exception handling stub routines. Lint points them out
as unused statics functions.
-"i source" only shows you info about files that it can read. When it
-can't read a file and complains, you can't see any info about it, like
-where it was compiled. Perhaps "i source" should take an argument
-like that of "list".
+Perhaps "i source" should take an argument like that of "list".
See if coredep.c's fetch_core_registers can be used on more machines.
E.g. MIPS (mips-xdep.c).
-coredep.c is completely broken. Needs work just to compile, it uses
-"u" and doesn't declare it, etc.
-
unpack_double() does not handle IEEE float on the target unless the host
is also IEEE. Death on a vax.
-Test cross-debugging Unix-to-Unix.
-
-Check the RAPP remote protocol. What is it? It's in Makefile.dist
-and one ChangeLog entry.
-
Set up interface between GDB and INFO so that you can hop into interactive
INFO and back out again. When running under Emacs, should use Emacs
info, else fork the info program. Installation of GDB should install
its texinfo files into the info tree automagically, including the readline
-texinfo files..
-
-Improve backtrace output to avoid line wraps. Prettify it.
+texinfo files.
-"help address" ought to find the "help set addressprint" entry.
+"help address" ought to find the "help set print address" entry.
Remove the VTBL internal guts from printouts of C++ structs, unless
vtblprint is set.
-Remove "at 0xnnnn" from the "b foo" response, if !addressprint and if
+Remove "at 0xnnnn" from the "b foo" response, if `print address off' and if
it matches the source line indicated.
The prompt at end of screen should accept space as well as CR.
-"List" should put you into a pseudo-"more" where you can hit space
-to get more, forever to eof.
+"List" should put you into a pseudo-"more" where you can hit space to
+get more, forever to eof. (questionable--you can already hit return
+to get more, and modal user interfaces are evil -kingdon, 28 Oct
+1993).
Check STORE_RETURN_VALUE on all architectures. Check near it in tm-sparc.h
for other bogosities.
vtblprint of a vtbl should demangle the names it's printing.
-Backtrace should point out what the currently selected frame is, in its
-display, perhaps showing ">3 foo (bar, ...)" rather than "#3 foo (bar, ...)".
+Backtrace should point out what the currently selected frame is, in
+its display, perhaps showing "@3 foo (bar, ...)" or ">3 foo (bar,
+...)" rather than "#3 foo (bar, ...)".
"i program" should work for core files, and display more info, like what
actually caused it to die.
-Hitting ^Z to an inferior doesn't work right, it takes several continues
-to make it actually go.
-
-"i fun" doesn't show misc function vector symbols.
-
"x/10i" should shorten the long name, if any, on subsequent lines.
Check through the code for FIXME comments and fix them. dbxread.c,
to get to that spot by accident. E.g. "n" over execute_command which has
an error.
-Watchpoints seem not entirely reliable.
+Watchpoints seem not entirely reliable, though they haven't failed me recently.
"set zeroprint off", don't bother printing members of structs which are entirely
zero. Useful for those big structs with few useful members.
call functions in the child, and while there, the child is interrupted
with a signal, or hits a breakpoint.)
-Symbol completion with TAB does not unmangle names!
-
help completion, help history should work.
-Symbol completion doesn't handle e.g. W::f. (symtab.c,
-make_symbol_completion_list).
-
-AMD version: ^C should do ^Ak to stop ebmon.
-
Check that we can handle stack trace through varargs AND alloca in same
function, on 29K.
wait_for_inferior loops forever if wait() gives it an error.
-"i frame" arg formatting sucks. Should wrap lines.
-"bt" arg formatting needs the same treatment .
-
"i frame" shows wrong "arglist at" location, doesn't show where the args
should be found, only their actual values.
-Symbolic display of addrs, (& disassembly prefixes), don't show static
-fns, e.g. enable_command in gdb.
-
-'ptype yylval' ==> "union YYSTYPE { ..... }". However, it is not a
-union YYSTYPE, but is simply a YYSTYPE, which is a typedef for an
-unnamed union.
-
-"show all" should work.
-
There should be a way for "set" commands to validate the new setting
before it takes effect.
-The "display" command should become the "always" command, e.g.
- "always print XXX"
- "always p/xxx XXX"
- "always echo foo"
- "always call XXX"
- "always x/i $pc", etc.
-
A mess of floating point opcodes are missing from sparc-opcode.h.
Also, a little program should test the table for bits that are
overspecified or underspecified. E.g. if the must-be-ones bits
should end up coming back the same (modulo transformation comments)
if fed to "gas" then the .o is fed to gdb for disassembly.
-Merge the xxx-opcode.h files with gas again...
-
Eliminate all the core_file_command's in all the xdep files.
Eliminate separate declarations of registers[] everywhere.
Line numbers are off in some spots. In proceed() at 1st "oneproc = 1",
it seems to run that statement, but it doesn't actually.
-Perhaps the tdep and xdep files, and the tm and xm files, into a config
-subdirectory. If not, at least straighten out their names so that
+Perhaps move the tdep, xdep, and nat files, into the config
+subdirectories. If not, at least straighten out their names so that
they all start with the machine name.
inferior_status should include stop_print_frame. It won't need to be
i line VAR produces "Line number not known for symbol ``var''.". I
thought we were stashing that info now!
-Make sure we can handle executables with no symbol info, e.g. /bin/csh.
-
-We should be able to write to executables that aren't running.
-
We should be able to write to random files at hex offsets like adb.
-Tiemann: It is very painful to look at fp registers that hold
-double precision values. GDB is happy to show them to you as single
-precision, but you cannot look at them as doubles. Perhaps casting
-should be changed to make this work; or maybe a new "set" option that
-sets the default fp precision to single, double, or quad. This is not
-urgent, but would be nice to get into GDB 4.0.
-
Make "target xxx" command interruptible.
Handle add_file with separate text, data, and bss addresses. Maybe
in a dynamic linking environment. Should remember the last copy loaded,
but not get too snowed if it finds references to the older copy.
-Implement have_memory, have_stack, have_registers, have_execution.
-Memory: core, exec, child, vxworks even without child.
-stack: core, child, vxworks with child
-registers: core, child, vxworks with child
-execution: child, vxworks with child.
-
The original BFD core dump reading routine would itself coredump when fed
a garbage file as a core file. Does the current one?
-Breakpoints should not be inserted and deleted all the time. Only the
-one(s) there should be removed when we have to step over one. Support
-breakpoints that don't have to be removed to step over them.
-
-Stop reading stop_registers!
-
Generalize and Standardize the RPC interface to a target program,
-improve it beyond the "ptrace" interface, and see if it can become a standard
-for remote debugging. Is WRS interested in donating their target-end
-code?
+improve it beyond the "ptrace" interface, and see if it can become a
+standard for remote debugging.
Remove all references to:
text_offset
examined, you get "Couldn't read float regs from core file"...if
indeed it can't. generic_mourn_inferior...
-...
-
-Check signal argument to remote proceed's and error if set.
-
-Handle floating point registers in core files under BFD. Currently
-they are punted.
+Have remote targets give a warning on a signal argument to
+target_resume. Or better yet, extend the protocols so that it works
+like it does on the Unix-like systems.
Sort help and info output.
Re-organize help categories into things that tend to fit on a screen
and hang together.
-When trying to print source lines but you can't find the file,
-print the file name and line number, and leave it selected anyway
-so "i source" will show it.
-
renote-nindy.c handles interrupts poorly; it error()s out of badly
chosen places, e.g. leaving current_frame zero, which causes core dumps
on the next command.
probably guessed wrong, or left them "for later" when I have a
machine that can attempt to build them.
-Use the complain() mechanism for handling all the error() calls in dbxread.c,
-and in similar situations in coffread.c and mipsread.c.
-
When doing "step" or "next", if a few lines of source are skipped between
the previous line and the current one, print those lines, not just the
last line of a multiline statement.
for ANSI C and consistency on arrays and functions.
For "float point[15];":
ptype &point[4] ==> Attempt to take address of non-lvalue.
-p &point[4] ==> Dereferences point[4] rather than giving you point+4.
For "char *malloc();":
ptype malloc ==> "char *()"; should be same as
ptype &malloc ==> "char *(*)()"
call printf ("%x\n", malloc) ==> wierd value, should be same as
call printf ("%x\n", &malloc) ==> correct value
-Fix symbol reading in the presence of interrupts. It currently leaves a
-cleanup to blow away the entire symbol table when a QUIT occurs.
+Fix dbxread.c symbol reading in the presence of interrupts. It
+currently leaves a cleanup to blow away the entire symbol table when a
+QUIT occurs. (What's wrong with that? -kingdon, 28 Oct 1993).
+
+Mipsread.c reads include files depth-first, because the dependencies
+in the psymtabs are way too inclusive (it seems to me). Figure out what
+really depends on what, to avoid recursing 20 or 30 times while reading
+real symtabs.
+
+value_add() should be subtracting the lower bound of arrays, if known,
+and possibly checking against the upper bound for error reporting.
+
+mipsread.c symbol table allocation and deallocation should be checked.
+My suspicion is that it's full of memory leaks.
+
+SunOS should have a target_lookup_symbol() for common'd things allocated
+by the shared library linker ld.so.
+
+When listing source lines, check for a preceding \n, to verify that
+the file hasn't changed out from under us.
+
+When listing source lines, eat leading whitespace corresponding to the
+line-number prefix we print. This avoids long lines wrapping.
+
+mipsread.c needs to check for old symtabs and psymtabs for the same
+files, the way it happens for dbxread.c and coffread.c, for VxWorks
+incremental symbol table reloading.
+
+Get all the remote systems (where the protocol allows it) to be able to
+stop the remote system when the GDB user types ^C (like remote.c
+does). For ebmon, use ^Ak.
+Possible feature: A version of the "disassemble" command which shows
+both source and assembly code ("set symbol-filename on" is a partial
+solution).
projects / deliverable / binutils-gdb.git / blobdiff