[Lazarus] Single-stepping assembler

Sat Sep 10 22:16:40 CEST 2011

On 10/09/2011 20:50, Mark Morgan Lloyd wrote:
> Martin wrote:
>> On 10/09/2011 19:13, Mark Morgan Lloyd wrote:
>>>>
>>>>> I've reverted from FPC 2.7.1 to 2.4.4 which was previously OK 
>>>>> (apart from floating-point code generation issues) without 
>>>>> significant change to the IDE behaviour.
>>>>>
>>>>
>>>> And did that help?
>>>
>>>
>>> Not at all I'm afraid, i.e. the problem appears to stay with Lazarus 
>>> rather than with the compiler.
>>>
>>
>> If you start Lazarus inside gdb? and then interrupt it, and try to 
>> get a bt?
>
> With debugging symbols, with hints disabled, with gdb. Console output 
> follows, not sure you're going to like it.
>
> >> TCmdLineDebugger.SendCmdLn "set width 50000"
> << TCmdLineDebugger.ReadLn "&"set width 50000\n""
>   [Debugger] Log output: &"set width 50000\n"
> << TCmdLineDebugger.ReadLn "^done"
> << TCmdLineDebugger.ReadLn "(gdb) "
> >> TCmdLineDebugger.SendCmdLn "set inferior-tty /dev/pts/2"

Ok, so we may have 2 issues at and.

the debugger never returns on
   set inferior-tty /dev/pts/2
which should have been created by the IDE.

or the IDE never gets the result, because something went wrong with 
creating it => but then it should not have gotten as far as sending the 
above...

So still the below stacktrace,. shows the IDE waiting for gdb to return 
output. yet it should do processMessages, so the ide should be responsive.
Strange

anyway:
in options, on the debugger tab (where you select /usr/bin/gdb), is a 
list of setting (in an object inspector like grid)
One of the settings is
    ConsoleTty
it is empty by default.
Put /dev/null in there  and see if it helps.

Or if you need to see the debugged apps terminal output, then open a 
terminal (xterm, or any other) yourself, type "pty", and it will give 
you something like /dev/pts/<n>  which you can put into that setting (so 
long as you leave that terminal open.

I wonder why that hangs. Nothing there should have changed...
unless some file/handle stuff in fpc changed? getpt() fcntl() 
tcsetattr() __write()  ....

> ^C
> Program received signal SIGINT, Interrupt.
> [Switching to Thread 0xf7f6daa0 (LWP 13397)]
> 0xf7f0f25c in __read_nocancel () from /lib/libpthread.so.0
> (gdb) bt
> #0  0xf7f0f25c in __read_nocancel () from /lib/libpthread.so.0
> #1  0x00ae7450 in TPSEUDOTERMINAL__READ (this=0xf61fe580, result=0x0)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmimiscclasses.pp:539
> #2  0x00ae7570 in TPSEUDOTERMINAL__CHECKCANREAD (this=0xf61fe580)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmimiscclasses.pp:546
> #3  0x00aae40c in TGDBMIDEBUGGER__PROCESSWHILEWAITFORHANDLES 
> (this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:6878
> #4  0x00a72cd4 in TCMDLINEDEBUGGER__WAITFORHANDLES 
> (AHANDLES=<incomplete type>, ATIMEOUT=-1, highAHANDLES=0,
>     this=0xf61cad20) at 
> /usr/local/share/lazarus-trunk/debugger/cmdlinedebugger.pp:166
> #5  0x00a738e8 in TCMDLINEDEBUGGER__READLINE (APEEK=false, 
> ATIMEOUT=-1, this=0xf61cad20, result=0x0)
>     at /usr/local/share/lazarus-trunk/debugger/cmdlinedebugger.pp:423
> #6  0x00a735bc in TCMDLINEDEBUGGER__READLINE (ATIMEOUT=-1, 
> this=0xf61cad20, result=0x0)
>     at /usr/local/share/lazarus-trunk/debugger/cmdlinedebugger.pp:352
> #7  0x00aba070 in TGDBMIDEBUGGERCOMMAND__PROCESSRESULT (ARESULT={STATE 
> = DSNONE, VALUES = 0x0, FLAGS = []},
>     ATIMEOUT=-1, this=0xf5b7b980) at 
> /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:9301
> #8  0x00ab95bc in TGDBMIDEBUGGERCOMMAND__EXECUTECOMMAND 
> (ACOMMAND=0xf5b94cd8 'set inferior-tty /dev/pts/2',
>     ARESULT={STATE = DSNONE, VALUES = 0x0, FLAGS = []}, AFLAGS=[], 
> ATIMEOUT=-1, this=0xf5b7b980)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:9123
> #9  0x00ab9f88 in TGDBMIDEBUGGERCOMMAND__EXECUTECOMMAND 
> (ACOMMAND=0x10d0e78 'set inferior-tty %s',
>     AVALUES=<incomplete type>, ARESULT={STATE = DSNONE, VALUES = 0x0, 
> FLAGS = []}, AFLAGS=[], ATIMEOUT=-1,
>     highAVALUES=0, this=0xf5b7b980) at 
> /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:9162
> #10 0x00a9d074 in TGDBMIDEBUGGERCOMMANDSTARTDEBUGGING__DOEXECUTE 
> (this=0xf5b7b980)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:3813
> #11 0x00abe1e4 in TGDBMIDEBUGGERCOMMAND__EXECUTE (this=0xf5b7b980)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:9904
> #12 0x00aaa150 in TGDBMIDEBUGGER__RUNQUEUE (this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:5863
> #13 0x00aaaa98 in TGDBMIDEBUGGER__QUEUECOMMAND (ACOMMAND=0xf5b7b980, 
> FORCEQUEUE=false, this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:5984
> #14 0x00aae394 in TGDBMIDEBUGGER__STARTDEBUGGING 
> (ACONTINUECOMMAND=0xf5ccfaa0, this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:6867
> #15 0x00aae29c in TGDBMIDEBUGGER__STARTDEBUGGING 
> (ACONTINUECOMMAND=ECTCONTINUE, this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:6851
> #16 0x00aabd7c in TGDBMIDEBUGGER__GDBRUN (this=0xf61cad20)
>     at /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:6228
> #17 0x00aad050 in TGDBMIDEBUGGER__REQUESTCOMMAND (ACOMMAND=DCRUN, 
> APARAMS=<incomplete type>, highAPARAMS=-1,
>     this=0xf61cad20) at 
> /usr/local/share/lazarus-trunk/debugger/gdbmidebugger.pp:6641
> #18 0x005cdf14 in TDEBUGGER__REQCMD (ACOMMAND=DCRUN, 
> APARAMS=<incomplete type>, highAPARAMS=-1,
>     this=0xf61cad20) at 
> /usr/local/share/lazarus-trunk/debugger/debugger.pp:5454
> #19 0x005ce030 in TDEBUGGER__RUN (this=0xf61cad20) at 
> /usr/local/share/lazarus-trunk/debugger/debugger.pp:5468
> #20 0x005bf1e4 in TDEBUGMANAGER__RUNDEBUGGER (this=0xf6b842f0) at 
> debugmanager.pas:2220
> #21 0x005b6dcc in TDEBUGMANAGER__ONRUNTIMER (SENDER=0xf6226c80, 
> this=0xf6b842f0) at debugmanager.pas:661
> #22 0x003512b4 in TCUSTOMTIMER__DOONTIMER (this=0xf6226c80) at 
> customtimer.pas:181
> #23 0x003511d8 in TCUSTOMTIMER__TIMER (this=0xf6226c80) at 
> customtimer.pas:156
> #24 0x00322b98 in GTKTIMERCB (DATA=0xf61f0fd0) at gtk2callback.inc:2430
> #25 0xf7840b40 in ?? () from /usr/lib/libglib-2.0.so.0
> #26 0xf7840b40 in ?? () from /usr/lib/libglib-2.0.so.0
> Backtrace stopped: previous frame identical to this frame (corrupt 
> stack?)
>
> 0 1>markMLl at pye-dev-04:/usr/local/share/lazarus$ gdb --version
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