Conference turris::decladebug

915.0. "Pressing Continue too soon hangs ladebug" by CXXC::REINIG (This too shall change) Tue Apr 08 1997 11:38

This should be reproducible with the exx in ~reinig/public

    augie> dxladebug $CEXE/exx
    Warning: Cannot convert string 
            "-*-COURIER-BOLD-R-*--*-100-*-*-*-*-ISO8859-1 " to type FontStruct

    
I get

    Welcome to the Ladebug Debugger Version 4.0-35
    Directory search path for source files:
     . .
    The "ignore" command has failed because there is no current process.
    Setting initial break point on routine "GEMSRC/gem_cp_ultrix.bli"`main
    [1] when [main:1759 0x24134a5c]
    [1] stopped at [main:1759 0x24134a5c]
    (Cannot find source file GEMSRC/gem_cp_ultrix.bli)
    No source line for address 0x24134a5c for display in Source View
    (ladebug)

No I press the Continue button

    (ladebug) cont

Ladebug is now hung.

.dbxinit is:

use . 
# playback input /usr/proj/gemproj/.dbxinit
alias dnode(DBGnode)		"call gem_dm_dump_jacket(DBGnode,gem_db_g_debug,368)"
alias dnodef(DBGnode,DBGflags)	"call gem_dm_dump_jacket(DBGnode,gem_db_g_debug,DBGflags)"
alias dlist(DBGnode)		"call gem_dm_dump_list_jacket(DBGnode,gem_db_g_debug,368,0)"
alias dlistl(DBGnode,DBGlink)	"call gem_dm_dump_list_jacket(DBGnode,gem_db_g_debug,368,DBGlink)"
alias dlistf(DBGnode,DBGflags)	"call gem_dm_dump_list_jacket(DBGnode,gem_db_g_debug,DBGflags,0)"
alias dtree(DBGnode)		"call gem_dm_dump_jacket(DBGnode,gem_db_g_debug,376)"
alias dtreef(DBGnode,DBGflags)	"call gem_dm_dump_jacket(DBGnode,gem_db_g_debug,DBGflags)"
alias dname(DBGnode)		"call gem_dm_put_sym_name(DBGnode,gem_db_g_debug,368,0,0,3);call gem_tx_put_eol(gem_db_g_debug,0,1)"
alias dexpr(DBGnode)		"call gem_dm_dump_expression_jacket(DBGnode,gem_db_g_debug,1)"
alias davr(DBGavr)		"call gem_dm_dump_avr_jacket(DBGavr,gem_db_g_debug,368,0,3)"
alias davrf(DBGavr,DBGflags)	"call gem_dm_dump_avr_jacket(DBGavr,gem_db_g_debug,DBGflags,0,3)"
alias dloc(DBGlocator)		"call gem_dm_dump_locator(gem_db_g_debug,DBGlocator);call gem_tx_put_eol(gem_db_g_debug)"

alias output_to(DBGfcb)		"call gem_db_output_to(DBGfcb)"
alias no_output_to(DBGfcb)	"call gem_db_no_output_to(DBGfcb)"
alias no_output			"call gem_db_no_output"
alias debug_to(DBGfcb)		"call gem_db_debug_to(DBGfcb)"
alias no_debug_to(DBGfcb)	"call gem_db_no_debug_to(DBGfcb)"
alias no_debug			"call gem_db_no_debug"

alias stop_at_tuple(DBGline,DBGexpcnt)	"stop at DBGline if tuple.gem_tpl_expr_count == DBGexpcnt"
alias stop_in_tuple(DBGrtn,DBGexpcnt)	"stop in DBGrtn if tuple.gem_tpl_expr_count == DBGexpcnt"
alias stopi_at_tuple(DBGaddr,DBGexpcnt) "stopi at DBGaddr if tuple.gem_tpl_expr_count == DBGexpcnt"

alias evbreak(DBGstring)	     	"call gem_db_breakz(DBGstring,0)"
alias evbreakc(DBGstring,DBGcount)    	"call gem_db_breakz(DBGstring,DBGcount)"
alias evtrace(DBGstring)	     	"call gem_db_tracez(DBGstring,0)"
alias evtracec(DBGstring,DBGcount)    	"call gem_db_tracez(DBGstring,DBGcount)"
alias evcancel(DBGstring)	     	"call gem_db_cancelz(DBGstring)"
alias evshow(DBGstring)		     	"call gem_db_displayz(DBGstring,7,gem_db_g_debug)"
alias evshow_break(DBGstring)	     	"call gem_db_displayz(DBGstring,1,gem_db_g_debug)"
alias evshow_trace(DBGstring)	     	"call gem_db_displayz(DBGstring,2,gem_db_g_debug)"

# ignore SEGV
ignore FPE
set $verbose=1

The debugger should not display the error in response to the "ignore"
command in the .dbxinit file; that's a problem (in the engine -- here's a
simple reproducer:

    host> ladebug
    Welcome to the Ladebug Debugger Version 4.0-35
    (ladebug) ignore FPE
    The "ignore" command has failed because there is no current process.
    (ladebug) q

).

The fact that the debugger appeared hung is that the program being debugged
is a compiler that is expecting source code to be input.  So we can
consider this part of the note to be a request that the debugger in some
way indicate that the program being debugged is expecting input.

-Chris

The debugger appearing to be hung just because the program is awaiting input
is a major usability problem.  I have put it high on our task list.

/Bevin