@ -1,5 +1,5 @@
/* Start (run) and stop the inferior process, for GDB.
/* Start (run) and stop the inferior process, for GDB.
Copyright ( C ) 1986 , 1987 , 1988 , 1989 , 1991 Free Software Foundation , Inc . Copyright 1986 , 1987 , 1988 , 1989 , 1991 , 1992 Free Software Foundation , Inc .
This file is part of GDB . This file is part of GDB .
@ -146,13 +146,35 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
extern int original_stack_limit ; extern int original_stack_limit ;
# endif /* SET_STACK_LIMIT_HUGE */ # endif /* SET_STACK_LIMIT_HUGE */
extern char * getenv ( ) ; /* Prototypes for local functions */
extern char * * environ ;
extern void new_tty_prefork ( ) ; /* In inflow.c */ static void
signals_info PARAMS ( ( char * ) ) ;
extern struct target_ops child_ops ; /* In inftarg.c */ static void
handle_command PARAMS ( ( char * , int ) ) ;
static void
sig_print_info PARAMS ( ( int ) ) ;
static void
sig_print_header PARAMS ( ( void ) ) ;
static void
remove_step_breakpoint PARAMS ( ( void ) ) ;
static void
insert_step_breakpoint PARAMS ( ( void ) ) ;
static void
resume PARAMS ( ( int , int ) ) ;
static void
resume_cleanups PARAMS ( ( int ) ) ;
extern char * * environ ;
extern struct target_ops child_ops ; /* In inftarg.c */
/* Sigtramp is a routine that the kernel calls (which then calls the
/* Sigtramp is a routine that the kernel calls (which then calls the
signal handler ) . On most machines it is a library routine that signal handler ) . On most machines it is a library routine that
@ -170,6 +192,13 @@ extern struct target_ops child_ops; /* In inftarg.c */
( name & & ! strcmp ( " _sigtramp " , name ) ) ( name & & ! strcmp ( " _sigtramp " , name ) )
# endif # endif
/* GET_LONGJMP_TARGET returns the PC at which longjmp() will resume the
program . It needs to examine the jmp_buf argument and extract the PC
from it . The return value is non - zero on success , zero otherwise . */
# ifndef GET_LONGJMP_TARGET
# define GET_LONGJMP_TARGET(PC_ADDR) 0
# endif
/* Tables of how to react to signals; the user sets them. */ /* Tables of how to react to signals; the user sets them. */
static char signal_stop [ NSIG ] ; static char signal_stop [ NSIG ] ;
@ -250,12 +279,6 @@ extern int one_stepped; /* From machine dependent code */
extern void single_step ( ) ; /* Same. */ extern void single_step ( ) ; /* Same. */
# endif /* NO_SINGLE_STEP */ # endif /* NO_SINGLE_STEP */
static void insert_step_breakpoint ( ) ;
static void remove_step_breakpoint ( ) ;
/*static*/ void wait_for_inferior ( ) ;
void init_wait_for_inferior ( ) ;
void normal_stop ( ) ;
/* Things to clean up if we QUIT out of resume (). */ /* Things to clean up if we QUIT out of resume (). */
/* ARGSUSED */ /* ARGSUSED */
@ -529,11 +552,15 @@ child_create_inferior (exec_file, allargs, env)
# ifdef TIOCGPGRP # ifdef TIOCGPGRP
/* Run inferior in a separate process group. */ /* Run inferior in a separate process group. */
# ifdef NEED_POSIX_SETPGID
debug_setpgrp = setpgid ( 0 , 0 ) ;
# else
# ifdef USG # ifdef USG
debug_setpgrp = setpgrp ( ) ; debug_setpgrp = setpgrp ( ) ;
# else # else
debug_setpgrp = setpgrp ( getpid ( ) , getpid ( ) ) ; debug_setpgrp = setpgrp ( getpid ( ) , getpid ( ) ) ;
# endif # endif /* USG */
# endif /* NEED_POSIX_SETPGID */
if ( debug_setpgrp = = - 1 ) if ( debug_setpgrp = = - 1 )
perror ( " setpgrp failed in child " ) ; perror ( " setpgrp failed in child " ) ;
# endif /* TIOCGPGRP */ # endif /* TIOCGPGRP */
@ -598,10 +625,6 @@ child_create_inferior (exec_file, allargs, env)
clear_proceed_status ( ) ; clear_proceed_status ( ) ;
# if defined (START_INFERIOR_HOOK)
START_INFERIOR_HOOK ( ) ;
# endif
/* We will get a trace trap after one instruction.
/* We will get a trace trap after one instruction.
Continue it automatically . Eventually ( after shell does an exec ) Continue it automatically . Eventually ( after shell does an exec )
it will get another trace trap . Then insert breakpoints and continue . */ it will get another trace trap . Then insert breakpoints and continue . */
@ -718,7 +741,7 @@ child_attach (args, from_tty)
if ( target_has_execution ) if ( target_has_execution )
{ {
if ( query ( " A program is being debugged already. Kill it? " ) ) if ( query ( " A program is being debugged already. Kill it? " ) )
target_kill ( ( char * ) 0 , from_tty ) ; target_kill ( ) ;
else else
error ( " Inferior not killed. " ) ; error ( " Inferior not killed. " ) ;
} }
@ -770,16 +793,7 @@ wait_for_inferior ()
struct symtab_and_line sal ; struct symtab_and_line sal ;
int remove_breakpoints_on_following_step = 0 ; int remove_breakpoints_on_following_step = 0 ;
int current_line ; int current_line ;
int handling_longjmp = 0 ; /* FIXME */
#if 0
/* This no longer works now that read_register is lazy;
it might try to ptrace when the process is not stopped . */
prev_pc = read_pc ( ) ;
( void ) find_pc_partial_function ( prev_pc , & prev_func_name ,
& prev_func_start ) ;
prev_func_start + = FUNCTION_START_OFFSET ;
prev_sp = read_register ( SP_REGNUM ) ;
# endif /* 0 */
sal = find_pc_line ( prev_pc , 0 ) ; sal = find_pc_line ( prev_pc , 0 ) ;
current_line = sal . line ; current_line = sal . line ;
@ -816,7 +830,7 @@ wait_for_inferior ()
stop_print_frame = 0 ; stop_print_frame = 0 ;
stop_signal = WTERMSIG ( w ) ; stop_signal = WTERMSIG ( w ) ;
target_terminal_ours ( ) ; /* Must do this before mourn anyway */ target_terminal_ours ( ) ; /* Must do this before mourn anyway */
target_kill ( ( char * ) 0 , 0 ) ; /* kill mourns as well */ target_kill ( ) ; /* kill mourns as well */
# ifdef PRINT_RANDOM_SIGNAL # ifdef PRINT_RANDOM_SIGNAL
printf ( " \n Program terminated: " ) ; printf ( " \n Program terminated: " ) ;
PRINT_RANDOM_SIGNAL ( stop_signal ) ; PRINT_RANDOM_SIGNAL ( stop_signal ) ;
@ -902,28 +916,30 @@ wait_for_inferior ()
will be set and we should check whether we ' ve hit the will be set and we should check whether we ' ve hit the
step breakpoint . */ step breakpoint . */
if ( stop_signal = = SIGTRAP & & trap_expected if ( stop_signal = = SIGTRAP & & trap_expected
& & step_resume_break_address = = 0 ) & & step_resume_break_address = = NULL )
bpstat_clear ( & stop_bpstat ) ; bpstat_clear ( & stop_bpstat ) ;
else else
{ {
/* See if there is a breakpoint at the current PC. */ /* See if there is a breakpoint at the current PC. */
# if DECR_PC_AFTER_BREAK # if DECR_PC_AFTER_BREAK
/* Notice the case of stepping through a jump
/* Notice the case of stepping through a jump
that le ads just after a breakpoint . that lan ds just after a breakpoint .
Don ' t confuse that with hitting the breakpoint . Don ' t confuse that with hitting the breakpoint .
What we check for is that 1 ) stepping is going on What we check for is that 1 ) stepping is going on
and 2 ) the pc before the last insn does not match and 2 ) the pc before the last insn does not match
the address of the breakpoint before the current pc . */ the address of the breakpoint before the current pc . */
if ( ! ( prev_pc ! = stop_pc - DECR_PC_AFTER_BREAK if ( prev_pc = = stop_pc - DECR_PC_AFTER_BREAK
& & step_range_end & & ! step_resume_break_address ) ) | | ! step_range_end
| | step_resume_break_address
| | handling_longjmp /* FIXME */ )
# endif /* DECR_PC_AFTER_BREAK not zero */ # endif /* DECR_PC_AFTER_BREAK not zero */
{ {
/* See if we stopped at the special breakpoint for
/* See if we stopped at the special breakpoint for
stepping over a subroutine call . If both are zero , stepping over a subroutine call . If both are zero ,
this wasn ' t the reason for the stop . */ this wasn ' t the reason for the stop . */
if ( stop_pc - DECR_PC_AFTER_BREAK if ( step_resume_break_address
= = step_resume_break_address & & stop_pc - DECR_PC_AFTER_BREAK
& & step_resume_break_address ) = = step_resume_break_address )
{ {
stop_step_resume_break = 1 ; stop_step_resume_break = 1 ;
if ( DECR_PC_AFTER_BREAK ) if ( DECR_PC_AFTER_BREAK )
@ -1008,64 +1024,131 @@ wait_for_inferior ()
one ( now fixed ) bug was caused by this - - a ! random_signal was one ( now fixed ) bug was caused by this - - a ! random_signal was
missing in one of the tests below . */ missing in one of the tests below . */
} }
/* Handle cases caused by hitting a breakpoint. */ /* Handle cases caused by hitting a breakpoint. */
if ( ! random_signal
& & ( bpstat_explains_signal ( stop_bpstat ) | | stop_step_resume_break ) )
{
/* Does a breakpoint want us to stop? */
if ( bpstat_stop ( stop_bpstat ) )
{
stop_print_frame = bpstat_should_print ( stop_bpstat ) ;
break ;
}
/* But if we have hit the step-resumption breakpoint,
remove it . It has done its job getting us here .
The sp test is to make sure that we don ' t get hung
up in recursive calls in functions without frame
pointers . If the stack pointer isn ' t outside of
where the breakpoint was set ( within a routine to be
stepped over ) , we ' re in the middle of a recursive
call . Not true for reg window machines ( sparc )
because the must change frames to call things and
the stack pointer doesn ' t have to change if it
the bp was set in a routine without a frame ( pc can
be stored in some other window ) .
The removal of the sp test is to allow calls to
alloca . Nasty things were happening . Oh , well ,
gdb can only handle one level deep of lack of
frame pointer . */
if ( stop_step_resume_break
& & ( step_frame_address = = 0
| | ( stop_frame_address = = step_frame_address ) ) )
{
remove_step_breakpoint ( ) ;
step_resume_break_address = 0 ;
/* If were waiting for a trap, hitting the step_resume_break
if ( ! random_signal )
doesn ' t count as getting it . */ if ( bpstat_explains_signal ( stop_bpstat ) )
if ( trap_expected ) {
another_trap = 1 ; CORE_ADDR jmp_buf_pc ;
}
/* Otherwise, must remove breakpoints and single-step
switch ( stop_bpstat - > breakpoint_at - > type ) /* FIXME */
to get us past the one we hit . */ {
else /* If we hit the breakpoint at longjmp, disable it for the
{ duration of this command . Then , install a temporary
remove_breakpoints ( ) ; breakpoint at the target of the jmp_buf . */
remove_step_breakpoint ( ) ; case bp_longjmp :
breakpoints_inserted = 0 ; disable_longjmp_breakpoint ( ) ;
another_trap = 1 ; remove_breakpoints ( ) ;
} breakpoints_inserted = 0 ;
if ( ! GET_LONGJMP_TARGET ( & jmp_buf_pc ) ) goto keep_going ;
/* We come here if we hit a breakpoint but should not
stop for it . Possibly we also were stepping /* Need to blow away step-resume breakpoint, as it
and should stop for that . So fall through and interferes with us */
test for stepping . But , if not stepping , remove_step_breakpoint ( ) ;
do not stop . */ step_resume_break_address = NULL ;
} stop_step_resume_break = 0 ;
#if 0 /* FIXME - Need to implement nested temporary breakpoints */
if ( step_over_calls > 0 )
set_longjmp_resume_breakpoint ( jmp_buf_pc ,
get_current_frame ( ) ) ;
else
# endif /* 0 */
set_longjmp_resume_breakpoint ( jmp_buf_pc , NULL ) ;
handling_longjmp = 1 ; /* FIXME */
goto keep_going ;
case bp_longjmp_resume :
remove_breakpoints ( ) ;
breakpoints_inserted = 0 ;
#if 0 /* FIXME - Need to implement nested temporary breakpoints */
if ( step_over_calls
& & ( stop_frame_address
INNER_THAN step_frame_address ) )
{
another_trap = 1 ;
goto keep_going ;
}
# endif /* 0 */
disable_longjmp_breakpoint ( ) ;
handling_longjmp = 0 ; /* FIXME */
break ;
default :
fprintf ( stderr , " Unknown breakpoint type %d \n " ,
stop_bpstat - > breakpoint_at - > type ) ;
case bp_watchpoint :
case bp_breakpoint :
case bp_until :
case bp_finish :
/* Does a breakpoint want us to stop? */
if ( bpstat_stop ( stop_bpstat ) )
{
stop_print_frame = bpstat_should_print ( stop_bpstat ) ;
goto stop_stepping ;
}
/* Otherwise, must remove breakpoints and single-step
to get us past the one we hit . */
else
{
remove_breakpoints ( ) ;
remove_step_breakpoint ( ) ;
breakpoints_inserted = 0 ;
another_trap = 1 ;
}
break ;
}
}
else if ( stop_step_resume_break )
{
/* But if we have hit the step-resumption breakpoint,
remove it . It has done its job getting us here .
The sp test is to make sure that we don ' t get hung
up in recursive calls in functions without frame
pointers . If the stack pointer isn ' t outside of
where the breakpoint was set ( within a routine to be
stepped over ) , we ' re in the middle of a recursive
call . Not true for reg window machines ( sparc )
because the must change frames to call things and
the stack pointer doesn ' t have to change if it
the bp was set in a routine without a frame ( pc can
be stored in some other window ) .
The removal of the sp test is to allow calls to
alloca . Nasty things were happening . Oh , well ,
gdb can only handle one level deep of lack of
frame pointer . */
/*
Disable test for step_frame_address match so that we always stop even if the
frames don ' t match . Reason : if we hit the step_resume_breakpoint , there is
no way to temporarily disable it so that we can step past it . If we leave
the breakpoint in , then we loop forever repeatedly hitting , but never
getting past the breakpoint . This change keeps nexting over recursive
function calls from hanging gdb .
*/
#if 0
if ( * step_frame_address = = 0
| | ( step_frame_address = = stop_frame_address ) )
# endif 0
{
remove_step_breakpoint ( ) ;
step_resume_break_address = 0 ;
/* If were waiting for a trap, hitting the step_resume_break
doesn ' t count as getting it . */
if ( trap_expected )
another_trap = 1 ;
}
}
/* We come here if we hit a breakpoint but should not
stop for it . Possibly we also were stepping
and should stop for that . So fall through and
test for stepping . But , if not stepping ,
do not stop . */
/* If this is the breakpoint at the end of a stack dummy,
/* If this is the breakpoint at the end of a stack dummy,
just stop silently . */ just stop silently . */
if ( ! random_signal if ( ! random_signal
@ -1147,9 +1230,9 @@ wait_for_inferior ()
/* ==> See comments at top of file on this algorithm. <==*/ /* ==> See comments at top of file on this algorithm. <==*/
else if ( stop_pc = = stop_func_start else if ( stop_pc = = stop_func_start
& & ( stop_func_start ! = prev_func_start & & ( stop_func_start ! = prev_func_start
| | prologue_pc ! = stop_func_start | | prologue_pc ! = stop_func_start
| | stop_sp ! = prev_sp ) ) | | stop_sp ! = prev_sp ) )
{ {
/* It's a subroutine call */ /* It's a subroutine call */
if ( step_over_calls > 0 if ( step_over_calls > 0
@ -1157,9 +1240,12 @@ wait_for_inferior ()
{ {
/* A subroutine call has happened. */ /* A subroutine call has happened. */
/* Set a special breakpoint after the return */ /* Set a special breakpoint after the return */
step_resume_break_address = step_resume_break_address =
ADDR_BITS_REMOVE ADDR_BITS_REMOVE (
( SAVED_PC_AFTER_CALL ( get_current_frame ( ) ) ) ; SAVED_PC_AFTER_CALL (
get_current_frame ( ) ) ) ;
step_resume_break_duplicate step_resume_break_duplicate
= breakpoint_here_p ( step_resume_break_address ) ; = breakpoint_here_p ( step_resume_break_address ) ;
if ( breakpoints_inserted ) if ( breakpoints_inserted )
@ -1229,19 +1315,22 @@ wait_for_inferior ()
step_range_start and step_range_end , and just continue . */ step_range_start and step_range_end , and just continue . */
sal = find_pc_line ( stop_pc , 0 ) ; sal = find_pc_line ( stop_pc , 0 ) ;
if ( step_range_end = = 1 | | /* Don't do this for stepi/nexti */ if ( step_range_end = = 1 /* Don't do this for stepi/nexti */
sal . line = = 0 | | /* Stop now if no line # info */ | | sal . line = = 0 /* Stop now if no line # info */
( current_line ! = sal . line | | ( current_line ! = sal . line
& & stop_pc = = sal . pc ) ) { & & stop_pc = = sal . pc ) )
stop_step = 1 ; {
break ; stop_step = 1 ;
} else { break ;
/* This is probably not necessary, but it probably makes
}
stepping more efficient , as we avoid calling find_pc_line ( ) else if ( sal . line ! = 0 )
for each instruction we step over . */ {
step_range_start = sal . pc ; /* This is probably not necessary, but it probably makes
step_range_end = sal . end ; stepping more efficient , as we avoid calling
} find_pc_line ( ) for each instruction we step over . */
step_range_start = sal . pc ;
step_range_end = sal . end ;
}
} }
} }
@ -1267,6 +1356,13 @@ wait_for_inferior ()
another_trap = 1 ; another_trap = 1 ;
} }
/* My apologies to the gods of structured programming. */
/* Come to this label when you need to resume the inferior. It's really much
cleaner at this time to do a goto than to try and figure out what the
if - else chain ought to look like ! ! */
keep_going :
/* Save the pc before execution, to compare with pc after stop. */ /* Save the pc before execution, to compare with pc after stop. */
prev_pc = read_pc ( ) ; /* Might have been DECR_AFTER_BREAK */ prev_pc = read_pc ( ) ; /* Might have been DECR_AFTER_BREAK */
prev_func_start = stop_func_start ; /* Ok, since if DECR_PC_AFTER
prev_func_start = stop_func_start ; /* Ok, since if DECR_PC_AFTER
@ -1313,7 +1409,7 @@ wait_for_inferior ()
breakpoints_inserted = 0 ; breakpoints_inserted = 0 ;
} }
else if ( ! breakpoints_inserted & & else if ( ! breakpoints_inserted & &
( step_resume_break_address ! = 0 | | ! another_trap ) ) ( step_resume_break_address ! = NULL | | ! another_trap ) )
{ {
insert_step_breakpoint ( ) ; insert_step_breakpoint ( ) ;
breakpoints_failed = insert_breakpoints ( ) ; breakpoints_failed = insert_breakpoints ( ) ;
@ -1346,12 +1442,16 @@ wait_for_inferior ()
} }
# endif /* SHIFT_INST_REGS */ # endif /* SHIFT_INST_REGS */
resume ( ( step_range_end & & ! step_resume_break_address ) resume ( ( ! step_resume_break_address
| | ( trap_expected & & ! step_resume_break_address ) & & ! handling_longjmp
& & ( step_range_end
| | trap_expected ) )
| | bpstat_should_step ( ) , | | bpstat_should_step ( ) ,
stop_signal ) ; stop_signal ) ;
} }
} }
stop_stepping :
if ( target_has_execution ) if ( target_has_execution )
{ {
/* Assuming the inferior still exists, set these up for next
/* Assuming the inferior still exists, set these up for next
@ -1801,4 +1901,3 @@ Pass and Stop may be combined.");
signal_print [ SIGURG ] = 0 ; signal_print [ SIGURG ] = 0 ;
# endif /* SIGURG */ # endif /* SIGURG */
} }
Stu Grossman
35 years ago