1 /* Start (run) and stop the inferior process, for GDB.
2 Copyright (C) 1986, 1987, 1988, 1989, 1991 Free Software Foundation, Inc.
4 This file is part of GDB.
6 GDB is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 1, or (at your option)
11 GDB is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GDB; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
20 /* Notes on the algorithm used in wait_for_inferior to determine if we
21 just did a subroutine call when stepping. We have the following
22 information at that point:
24 Current and previous (just before this step) pc.
25 Current and previous sp.
26 Current and previous start of current function.
28 If the start's of the functions don't match, then
30 a) We did a subroutine call.
32 In this case, the pc will be at the beginning of a function.
34 b) We did a subroutine return.
40 If we did a longjump, we were doing "nexti", since a next would
41 have attempted to skip over the assembly language routine in which
42 the longjmp is coded and would have simply been the equivalent of a
43 continue. I consider this ok behaivior. We'd like one of two
44 things to happen if we are doing a nexti through the longjmp()
45 routine: 1) It behaves as a stepi, or 2) It acts like a continue as
46 above. Given that this is a special case, and that anybody who
47 thinks that the concept of sub calls is meaningful in the context
48 of a longjmp, I'll take either one. Let's see what happens.
50 Acts like a subroutine return. I can handle that with no problem
53 -->So: If the current and previous beginnings of the current
54 function don't match, *and* the pc is at the start of a function,
55 we've done a subroutine call. If the pc is not at the start of a
56 function, we *didn't* do a subroutine call.
58 -->If the beginnings of the current and previous function do match,
61 a) We just did a recursive call.
63 In this case, we would be at the very beginning of a
64 function and 1) it will have a prologue (don't jump to
65 before prologue, or 2) (we assume here that it doesn't have
66 a prologue) there will have been a change in the stack
67 pointer over the last instruction. (Ie. it's got to put
68 the saved pc somewhere. The stack is the usual place. In
69 a recursive call a register is only an option if there's a
70 prologue to do something with it. This is even true on
71 register window machines; the prologue sets up the new
72 window. It might not be true on a register window machine
73 where the call instruction moved the register window
74 itself. Hmmm. One would hope that the stack pointer would
75 also change. If it doesn't, somebody send me a note, and
76 I'll work out a more general theory.
77 bug-gdb@prep.ai.mit.edu). This is true (albeit slipperly
78 so) on all machines I'm aware of:
80 m68k: Call changes stack pointer. Regular jumps don't.
82 sparc: Recursive calls must have frames and therefor,
85 vax: All calls have frames and hence change the
88 b) We did a return from a recursive call. I don't see that we
89 have either the ability or the need to distinguish this
90 from an ordinary jump. The stack frame will be printed
91 when and if the frame pointer changes; if we are in a
92 function without a frame pointer, it's the users own
95 c) We did a jump within a function. We assume that this is
96 true if we didn't do a recursive call.
98 d) We are in no-man's land ("I see no symbols here"). We
99 don't worry about this; it will make calls look like simple
100 jumps (and the stack frames will be printed when the frame
101 pointer moves), which is a reasonably non-violent response.
104 We skip this; it causes more problems than it's worth.
105 #ifdef SUN4_COMPILER_FEATURE
106 We do a special ifdef for the sun 4, forcing it to single step
107 into calls which don't have prologues. This means that we can't
108 nexti over leaf nodes, we can probably next over them (since they
109 won't have debugging symbols, usually), and we can next out of
110 functions returning structures (with a "call .stret4" at the end).
125 #include "inferior.h"
126 #include "breakpoint.h"
131 #include "terminal.h" /* For #ifdef TIOCGPGRP and new_tty */
136 /* unistd.h is needed to #define X_OK */
140 #include <sys/file.h>
143 #ifdef SET_STACK_LIMIT_HUGE
144 extern int original_stack_limit
;
145 #endif /* SET_STACK_LIMIT_HUGE */
147 /* Required by <sys/user.h>. */
148 #include <sys/types.h>
149 /* Required by <sys/user.h>, at least on system V. */
151 /* Needed by IN_SIGTRAMP on some machines (e.g. vax). */
152 #include <sys/param.h>
153 /* Needed by IN_SIGTRAMP on some machines (e.g. vax). */
154 #include <sys/user.h>
156 extern char *getenv ();
158 extern struct target_ops child_ops
; /* In inftarg.c */
160 /* Copy of inferior_io_terminal when inferior was last started. */
162 extern char *inferior_thisrun_terminal
;
165 /* Sigtramp is a routine that the kernel calls (which then calls the
166 signal handler). On most machines it is a library routine that
167 is linked into the executable.
169 This macro, given a program counter value and the name of the
170 function in which that PC resides (which can be null if the
171 name is not known), returns nonzero if the PC and name show
172 that we are in sigtramp.
174 On most machines just see if the name is sigtramp (and if we have
175 no name, assume we are not in sigtramp). */
176 #if !defined (IN_SIGTRAMP)
177 #define IN_SIGTRAMP(pc, name) \
178 name && !strcmp ("_sigtramp", name)
181 /* Tables of how to react to signals; the user sets them. */
183 static char signal_stop
[NSIG
];
184 static char signal_print
[NSIG
];
185 static char signal_program
[NSIG
];
187 /* Nonzero if breakpoints are now inserted in the inferior. */
188 /* Nonstatic for initialization during xxx_create_inferior. FIXME. */
190 /*static*/ int breakpoints_inserted
;
192 /* Function inferior was in as of last step command. */
194 static struct symbol
*step_start_function
;
196 /* Nonzero => address for special breakpoint for resuming stepping. */
198 static CORE_ADDR step_resume_break_address
;
200 /* Pointer to orig contents of the byte where the special breakpoint is. */
202 static char step_resume_break_shadow
[BREAKPOINT_MAX
];
204 /* Nonzero means the special breakpoint is a duplicate
205 so it has not itself been inserted. */
207 static int step_resume_break_duplicate
;
209 /* Nonzero if we are expecting a trace trap and should proceed from it. */
211 static int trap_expected
;
213 /* Nonzero if the next time we try to continue the inferior, it will
214 step one instruction and generate a spurious trace trap.
215 This is used to compensate for a bug in HP-UX. */
217 static int trap_expected_after_continue
;
219 /* Nonzero means expecting a trace trap
220 and should stop the inferior and return silently when it happens. */
224 /* Nonzero means expecting a trap and caller will handle it themselves.
225 It is used after attach, due to attaching to a process;
226 when running in the shell before the child program has been exec'd;
227 and when running some kinds of remote stuff (FIXME?). */
229 int stop_soon_quietly
;
231 /* Nonzero if pc has been changed by the debugger
232 since the inferior stopped. */
236 /* Nonzero if proceed is being used for a "finish" command or a similar
237 situation when stop_registers should be saved. */
239 int proceed_to_finish
;
241 /* Save register contents here when about to pop a stack dummy frame,
242 if-and-only-if proceed_to_finish is set.
243 Thus this contains the return value from the called function (assuming
244 values are returned in a register). */
246 char stop_registers
[REGISTER_BYTES
];
248 /* Nonzero if program stopped due to error trying to insert breakpoints. */
250 static int breakpoints_failed
;
252 /* Nonzero after stop if current stack frame should be printed. */
254 static int stop_print_frame
;
256 #ifdef NO_SINGLE_STEP
257 extern int one_stepped
; /* From machine dependent code */
258 extern void single_step (); /* Same. */
259 #endif /* NO_SINGLE_STEP */
261 static void insert_step_breakpoint ();
262 static void remove_step_breakpoint ();
263 /*static*/ void wait_for_inferior ();
264 void init_wait_for_inferior ();
268 /* Clear out all variables saying what to do when inferior is continued.
269 First do this, then set the ones you want, then call `proceed'. */
272 clear_proceed_status ()
275 step_range_start
= 0;
277 step_frame_address
= 0;
278 step_over_calls
= -1;
279 step_resume_break_address
= 0;
281 stop_soon_quietly
= 0;
282 proceed_to_finish
= 0;
283 breakpoint_proceeded
= 1; /* We're about to proceed... */
285 /* Discard any remaining commands or status from previous stop. */
286 bpstat_clear (&stop_bpstat
);
289 /* Basic routine for continuing the program in various fashions.
291 ADDR is the address to resume at, or -1 for resume where stopped.
292 SIGGNAL is the signal to give it, or 0 for none,
293 or -1 for act according to how it stopped.
294 STEP is nonzero if should trap after one instruction.
295 -1 means return after that and print nothing.
296 You should probably set various step_... variables
297 before calling here, if you are stepping.
299 You should call clear_proceed_status before calling proceed. */
302 proceed (addr
, siggnal
, step
)
310 step_start_function
= find_pc_function (read_pc ());
316 /* If there is a breakpoint at the address we will resume at,
317 step one instruction before inserting breakpoints
318 so that we do not stop right away. */
320 if (!pc_changed
&& breakpoint_here_p (read_pc ()))
325 write_register (PC_REGNUM
, addr
);
327 write_register (NPC_REGNUM
, addr
+ 4);
329 write_register (NNPC_REGNUM
, addr
+ 8);
334 if (trap_expected_after_continue
)
336 /* If (step == 0), a trap will be automatically generated after
337 the first instruction is executed. Force step one
338 instruction to clear this condition. This should not occur
339 if step is nonzero, but it is harmless in that case. */
341 trap_expected_after_continue
= 0;
345 /* We will get a trace trap after one instruction.
346 Continue it automatically and insert breakpoints then. */
350 int temp
= insert_breakpoints ();
353 print_sys_errmsg ("ptrace", temp
);
354 error ("Cannot insert breakpoints.\n\
355 The same program may be running in another process.");
357 breakpoints_inserted
= 1;
360 /* Install inferior's terminal modes. */
361 target_terminal_inferior ();
364 stop_signal
= siggnal
;
365 /* If this signal should not be seen by program,
366 give it zero. Used for debugging signals. */
367 else if (stop_signal
< NSIG
&& !signal_program
[stop_signal
])
370 /* Handle any optimized stores to the inferior NOW... */
371 #ifdef DO_DEFERRED_STORES
375 /* Resume inferior. */
376 target_resume (oneproc
|| step
|| bpstat_should_step (), stop_signal
);
378 /* Wait for it to stop (if not standalone)
379 and in any case decode why it stopped, and act accordingly. */
381 wait_for_inferior ();
386 /* This might be useful (not sure), but isn't currently used. See also
388 /* Writing the inferior pc as a register calls this function
389 to inform infrun that the pc has been set in the debugger. */
400 /* Record the pc and sp of the program the last time it stopped.
401 These are just used internally by wait_for_inferior, but need
402 to be preserved over calls to it and cleared when the inferior
404 static CORE_ADDR prev_pc
;
405 static CORE_ADDR prev_sp
;
406 static CORE_ADDR prev_func_start
;
407 static char *prev_func_name
;
409 /* Start an inferior Unix child process and sets inferior_pid to its pid.
410 EXEC_FILE is the file to run.
411 ALLARGS is a string containing the arguments to the program.
412 ENV is the environment vector to pass. Errors reported with error(). */
415 #define SHELL_FILE "/bin/sh"
419 child_create_inferior (exec_file
, allargs
, env
)
427 extern char *sys_errlist
[];
429 static char default_shell_file
[] = SHELL_FILE
;
432 /* Set debug_fork then attach to the child while it sleeps, to debug. */
433 static int debug_fork
= 0;
434 /* This is set to the result of setpgrp, which if vforked, will be visible
435 to you in the parent process. It's only used by humans for debugging. */
436 static int debug_setpgrp
= 657473;
438 /* The user might want tilde-expansion, and in general probably wants
439 the program to behave the same way as if run from
440 his/her favorite shell. So we let the shell run it for us.
441 FIXME, this should probably search the local environment (as
442 modified by the setenv command), not the env gdb inherited. */
443 shell_file
= getenv ("SHELL");
444 if (shell_file
== NULL
)
445 shell_file
= default_shell_file
;
447 len
= 5 + strlen (exec_file
) + 1 + strlen (allargs
) + 1 + /*slop*/ 10;
448 /* If desired, concat something onto the front of ALLARGS.
449 SHELL_COMMAND is the result. */
450 #ifdef SHELL_COMMAND_CONCAT
451 shell_command
= (char *) alloca (strlen (SHELL_COMMAND_CONCAT
) + len
);
452 strcpy (shell_command
, SHELL_COMMAND_CONCAT
);
454 shell_command
= (char *) alloca (len
);
455 shell_command
[0] = '\0';
457 strcat (shell_command
, "exec ");
458 strcat (shell_command
, exec_file
);
459 strcat (shell_command
, " ");
460 strcat (shell_command
, allargs
);
462 /* exec is said to fail if the executable is open. */
465 #if defined(USG) && !defined(HAVE_VFORK)
475 perror_with_name ("vfork");
483 /* Run inferior in a separate process group. */
484 debug_setpgrp
= setpgrp (getpid (), getpid ());
485 if (0 != debug_setpgrp
)
486 perror("setpgrp failed in child");
487 #endif /* TIOCGPGRP */
489 #ifdef SET_STACK_LIMIT_HUGE
490 /* Reset the stack limit back to what it was. */
494 getrlimit (RLIMIT_STACK
, &rlim
);
495 rlim
.rlim_cur
= original_stack_limit
;
496 setrlimit (RLIMIT_STACK
, &rlim
);
498 #endif /* SET_STACK_LIMIT_HUGE */
500 /* Tell the terminal handling subsystem what tty we plan to run on;
501 it will now switch to that one if non-null. */
503 new_tty (inferior_io_terminal
);
505 /* Changing the signal handlers for the inferior after
506 a vfork can also change them for the superior, so we don't mess
507 with signals here. See comments in
508 initialize_signals for how we get the right signal handlers
511 call_ptrace (0, 0, 0, 0); /* "Trace me, Dr. Memory!" */
512 execle (shell_file
, shell_file
, "-c", shell_command
, (char *)0, env
);
514 fprintf (stderr
, "Cannot exec %s: %s.\n", shell_file
,
515 errno
< sys_nerr
? sys_errlist
[errno
] : "unknown error");
520 /* Now that we have a child process, make it our target. */
521 push_target (&child_ops
);
523 #ifdef CREATE_INFERIOR_HOOK
524 CREATE_INFERIOR_HOOK (pid
);
527 /* The process was started by the fork that created it,
528 but it will have stopped one instruction after execing the shell.
529 Here we must get it up to actual execution of the real program. */
531 inferior_pid
= pid
; /* Needed for wait_for_inferior stuff below */
533 clear_proceed_status ();
535 #if defined (START_INFERIOR_HOOK)
536 START_INFERIOR_HOOK ();
539 /* We will get a trace trap after one instruction.
540 Continue it automatically. Eventually (after shell does an exec)
541 it will get another trace trap. Then insert breakpoints and continue. */
543 #ifdef START_INFERIOR_TRAPS_EXPECTED
544 pending_execs
= START_INFERIOR_TRAPS_EXPECTED
;
549 init_wait_for_inferior ();
551 /* Set up the "saved terminal modes" of the inferior
552 based on what modes we are starting it with. */
553 target_terminal_init ();
555 /* Install inferior's terminal modes. */
556 target_terminal_inferior ();
560 stop_soon_quietly
= 1; /* Make wait_for_inferior be quiet */
561 wait_for_inferior ();
562 if (stop_signal
!= SIGTRAP
)
564 /* Let shell child handle its own signals in its own way */
565 /* FIXME, what if child has exit()ed? Must exit loop somehow */
566 target_resume (0, stop_signal
);
570 /* We handle SIGTRAP, however; it means child did an exec. */
571 if (0 == --pending_execs
)
573 target_resume (0, 0); /* Just make it go on */
576 stop_soon_quietly
= 0;
578 /* Should this perhaps just be a "proceed" call? FIXME */
579 insert_step_breakpoint ();
580 breakpoints_failed
= insert_breakpoints ();
581 if (!breakpoints_failed
)
583 breakpoints_inserted
= 1;
584 target_terminal_inferior();
585 /* Start the child program going on its first instruction, single-
586 stepping if we need to. */
587 target_resume (bpstat_should_step (), 0);
588 wait_for_inferior ();
593 /* Start remote-debugging of a machine over a serial link. */
598 init_wait_for_inferior ();
599 clear_proceed_status ();
600 stop_soon_quietly
= 1;
604 /* Initialize static vars when a new inferior begins. */
607 init_wait_for_inferior ()
609 /* These are meaningless until the first time through wait_for_inferior. */
613 prev_func_name
= NULL
;
615 trap_expected_after_continue
= 0;
616 breakpoints_inserted
= 0;
617 mark_breakpoints_out ();
618 stop_signal
= 0; /* Don't confuse first call to proceed(). */
622 /* Attach to process PID, then initialize for debugging it
623 and wait for the trace-trap that results from attaching. */
626 child_attach (args
, from_tty
)
636 error_no_arg ("process-id to attach");
638 #ifndef ATTACH_DETACH
639 error ("Can't attach to a process on this machine.");
643 if (target_has_execution
)
645 if (query ("A program is being debugged already. Kill it? "))
646 target_kill ((char *)0, from_tty
);
648 error ("Inferior not killed.");
651 exec_file
= (char *) get_exec_file (1);
655 printf ("Attaching program: %s pid %d\n",
662 push_target (&child_ops
);
664 mark_breakpoints_out ();
665 target_terminal_init ();
666 clear_proceed_status ();
667 stop_soon_quietly
= 1;
668 /*proceed (-1, 0, -2);*/
669 target_terminal_inferior ();
670 wait_for_inferior ();
672 #endif /* ATTACH_DETACH */
675 /* Wait for control to return from inferior to debugger.
676 If inferior gets a signal, we may decide to start it up again
677 instead of returning. That is why there is a loop in this function.
678 When this function actually returns it means the inferior
679 should be left stopped and GDB should read more commands. */
688 CORE_ADDR stop_func_start
;
689 char *stop_func_name
;
690 CORE_ADDR prologue_pc
;
691 int stop_step_resume_break
;
692 struct symtab_and_line sal
;
693 int remove_breakpoints_on_following_step
= 0;
696 /* This no longer works now that read_register is lazy;
697 it might try to ptrace when the process is not stopped. */
698 prev_pc
= read_pc ();
699 (void) find_pc_partial_function (prev_pc
, &prev_func_name
,
701 prev_func_start
+= FUNCTION_START_OFFSET
;
702 prev_sp
= read_register (SP_REGNUM
);
707 /* Clean up saved state that will become invalid. */
709 flush_cached_frames ();
710 registers_changed ();
714 /* See if the process still exists; clean up if it doesn't. */
717 target_terminal_ours (); /* Must do this before mourn anyway */
719 printf ("\nProgram exited with code 0%o.\n",
720 (unsigned int)WEXITSTATUS (w
));
723 printf ("\nProgram exited normally.\n");
725 target_mourn_inferior ();
726 #ifdef NO_SINGLE_STEP
729 stop_print_frame
= 0;
732 else if (!WIFSTOPPED (w
))
734 stop_print_frame
= 0;
735 stop_signal
= WTERMSIG (w
);
736 target_terminal_ours (); /* Must do this before mourn anyway */
737 target_kill ((char *)0, 0); /* kill mourns as well */
738 #ifdef PRINT_RANDOM_SIGNAL
739 printf ("\nProgram terminated: ");
740 PRINT_RANDOM_SIGNAL (stop_signal
);
742 printf ("\nProgram terminated with signal %d, %s\n",
745 ? sys_siglist
[stop_signal
]
748 printf ("The inferior process no longer exists.\n");
750 #ifdef NO_SINGLE_STEP
756 #ifdef NO_SINGLE_STEP
758 single_step (0); /* This actually cleans up the ss */
759 #endif /* NO_SINGLE_STEP */
761 stop_pc
= read_pc ();
762 set_current_frame ( create_new_frame (read_register (FP_REGNUM
),
765 stop_frame_address
= FRAME_FP (get_current_frame ());
766 stop_sp
= read_register (SP_REGNUM
);
769 /* Don't care about return value; stop_func_start and stop_func_name
770 will both be 0 if it doesn't work. */
771 (void) find_pc_partial_function (stop_pc
, &stop_func_name
,
773 stop_func_start
+= FUNCTION_START_OFFSET
;
775 bpstat_clear (&stop_bpstat
);
777 stop_stack_dummy
= 0;
778 stop_print_frame
= 1;
779 stop_step_resume_break
= 0;
781 stopped_by_random_signal
= 0;
782 breakpoints_failed
= 0;
784 /* Look at the cause of the stop, and decide what to do.
785 The alternatives are:
786 1) break; to really stop and return to the debugger,
787 2) drop through to start up again
788 (set another_trap to 1 to single step once)
789 3) set random_signal to 1, and the decision between 1 and 2
790 will be made according to the signal handling tables. */
792 stop_signal
= WSTOPSIG (w
);
794 /* First, distinguish signals caused by the debugger from signals
795 that have to do with the program's own actions.
796 Note that breakpoint insns may cause SIGTRAP or SIGILL
797 or SIGEMT, depending on the operating system version.
798 Here we detect when a SIGILL or SIGEMT is really a breakpoint
799 and change it to SIGTRAP. */
801 if (stop_signal
== SIGTRAP
802 || (breakpoints_inserted
&&
803 (stop_signal
== SIGILL
804 || stop_signal
== SIGEMT
))
805 || stop_soon_quietly
)
807 if (stop_signal
== SIGTRAP
&& stop_after_trap
)
809 stop_print_frame
= 0;
812 if (stop_soon_quietly
)
815 /* Don't even think about breakpoints
816 if just proceeded over a breakpoint.
818 However, if we are trying to proceed over a breakpoint
819 and end up in sigtramp, then step_resume_break_address
820 will be set and we should check whether we've hit the
822 if (stop_signal
== SIGTRAP
&& trap_expected
823 && step_resume_break_address
== NULL
)
824 bpstat_clear (&stop_bpstat
);
827 /* See if there is a breakpoint at the current PC. */
828 #if DECR_PC_AFTER_BREAK
829 /* Notice the case of stepping through a jump
830 that leads just after a breakpoint.
831 Don't confuse that with hitting the breakpoint.
832 What we check for is that 1) stepping is going on
833 and 2) the pc before the last insn does not match
834 the address of the breakpoint before the current pc. */
835 if (!(prev_pc
!= stop_pc
- DECR_PC_AFTER_BREAK
836 && step_range_end
&& !step_resume_break_address
))
837 #endif /* DECR_PC_AFTER_BREAK not zero */
839 /* See if we stopped at the special breakpoint for
840 stepping over a subroutine call. If both are zero,
841 this wasn't the reason for the stop. */
842 if (stop_pc
- DECR_PC_AFTER_BREAK
843 == step_resume_break_address
844 && step_resume_break_address
)
846 stop_step_resume_break
= 1;
847 if (DECR_PC_AFTER_BREAK
)
849 stop_pc
-= DECR_PC_AFTER_BREAK
;
850 write_register (PC_REGNUM
, stop_pc
);
857 bpstat_stop_status (&stop_pc
, stop_frame_address
);
858 /* Following in case break condition called a
860 stop_print_frame
= 1;
865 if (stop_signal
== SIGTRAP
)
867 = !(bpstat_explains_signal (stop_bpstat
)
869 || stop_step_resume_break
870 || PC_IN_CALL_DUMMY (stop_pc
, stop_sp
, stop_frame_address
)
871 || (step_range_end
&& !step_resume_break_address
));
875 = !(bpstat_explains_signal (stop_bpstat
)
876 || stop_step_resume_break
877 /* End of a stack dummy. Some systems (e.g. Sony
878 news) give another signal besides SIGTRAP,
879 so check here as well as above. */
880 || (stop_sp INNER_THAN stop_pc
881 && stop_pc INNER_THAN stop_frame_address
)
884 stop_signal
= SIGTRAP
;
890 /* For the program's own signals, act according to
891 the signal handling tables. */
895 /* Signal not for debugging purposes. */
898 stopped_by_random_signal
= 1;
900 if (stop_signal
>= NSIG
901 || signal_print
[stop_signal
])
904 target_terminal_ours_for_output ();
905 #ifdef PRINT_RANDOM_SIGNAL
906 PRINT_RANDOM_SIGNAL (stop_signal
);
908 printf ("\nProgram received signal %d, %s\n",
911 ? sys_siglist
[stop_signal
]
913 #endif /* PRINT_RANDOM_SIGNAL */
916 if (stop_signal
>= NSIG
917 || signal_stop
[stop_signal
])
919 /* If not going to stop, give terminal back
920 if we took it away. */
922 target_terminal_inferior ();
925 /* Handle cases caused by hitting a breakpoint. */
928 && (bpstat_explains_signal (stop_bpstat
) || stop_step_resume_break
))
930 /* Does a breakpoint want us to stop? */
931 if (bpstat_stop (stop_bpstat
))
933 stop_print_frame
= bpstat_should_print (stop_bpstat
);
936 /* But if we have hit the step-resumption breakpoint,
937 remove it. It has done its job getting us here.
938 The sp test is to make sure that we don't get hung
939 up in recursive calls in functions without frame
940 pointers. If the stack pointer isn't outside of
941 where the breakpoint was set (within a routine to be
942 stepped over), we're in the middle of a recursive
943 call. Not true for reg window machines (sparc)
944 because the must change frames to call things and
945 the stack pointer doesn't have to change if it
946 the bp was set in a routine without a frame (pc can
947 be stored in some other window).
949 The removal of the sp test is to allow calls to
950 alloca. Nasty things were happening. Oh, well,
951 gdb can only handle one level deep of lack of
953 if (stop_step_resume_break
954 && (step_frame_address
== 0
955 || (stop_frame_address
== step_frame_address
)))
957 remove_step_breakpoint ();
958 step_resume_break_address
= 0;
960 /* If were waiting for a trap, hitting the step_resume_break
961 doesn't count as getting it. */
965 /* Otherwise, must remove breakpoints and single-step
966 to get us past the one we hit. */
969 remove_breakpoints ();
970 remove_step_breakpoint ();
971 breakpoints_inserted
= 0;
975 /* We come here if we hit a breakpoint but should not
976 stop for it. Possibly we also were stepping
977 and should stop for that. So fall through and
978 test for stepping. But, if not stepping,
982 /* If this is the breakpoint at the end of a stack dummy,
983 just stop silently. */
984 if (PC_IN_CALL_DUMMY (stop_pc
, stop_sp
, stop_frame_address
))
986 stop_print_frame
= 0;
987 stop_stack_dummy
= 1;
989 trap_expected_after_continue
= 1;
994 if (step_resume_break_address
)
995 /* Having a step-resume breakpoint overrides anything
996 else having to do with stepping commands until
997 that breakpoint is reached. */
999 /* If stepping through a line, keep going if still within it. */
1000 else if (!random_signal
1002 && stop_pc
>= step_range_start
1003 && stop_pc
< step_range_end
1004 /* The step range might include the start of the
1005 function, so if we are at the start of the
1006 step range and either the stack or frame pointers
1007 just changed, we've stepped outside */
1008 && !(stop_pc
== step_range_start
1009 && stop_frame_address
1010 && (stop_sp INNER_THAN prev_sp
1011 || stop_frame_address
!= step_frame_address
)))
1014 /* When "next"ing through a function,
1015 This causes an extra stop at the end.
1016 Is there any reason for this?
1017 It's confusing to the user. */
1018 /* Don't step through the return from a function
1019 unless that is the first instruction stepped through. */
1020 if (ABOUT_TO_RETURN (stop_pc
))
1028 /* We stepped out of the stepping range. See if that was due
1029 to a subroutine call that we should proceed to the end of. */
1030 else if (!random_signal
&& step_range_end
)
1032 if (stop_func_start
)
1034 prologue_pc
= stop_func_start
;
1035 SKIP_PROLOGUE (prologue_pc
);
1038 /* Did we just take a signal? */
1039 if (IN_SIGTRAMP (stop_pc
, stop_func_name
)
1040 && !IN_SIGTRAMP (prev_pc
, prev_func_name
))
1042 /* This code is needed at least in the following case:
1043 The user types "next" and then a signal arrives (before
1044 the "next" is done). */
1045 /* We've just taken a signal; go until we are back to
1046 the point where we took it and one more. */
1047 step_resume_break_address
= prev_pc
;
1048 step_resume_break_duplicate
=
1049 breakpoint_here_p (step_resume_break_address
);
1050 if (breakpoints_inserted
)
1051 insert_step_breakpoint ();
1052 /* Make sure that the stepping range gets us past
1053 that instruction. */
1054 if (step_range_end
== 1)
1055 step_range_end
= (step_range_start
= prev_pc
) + 1;
1056 remove_breakpoints_on_following_step
= 1;
1059 /* ==> See comments at top of file on this algorithm. <==*/
1061 else if (stop_pc
== stop_func_start
1062 && (stop_func_start
!= prev_func_start
1063 || prologue_pc
!= stop_func_start
1064 || stop_sp
!= prev_sp
))
1066 /* It's a subroutine call */
1067 if (step_over_calls
> 0
1068 || (step_over_calls
&& find_pc_function (stop_pc
) == 0))
1070 /* A subroutine call has happened. */
1071 /* Set a special breakpoint after the return */
1072 step_resume_break_address
=
1074 (SAVED_PC_AFTER_CALL (get_current_frame ()));
1075 step_resume_break_duplicate
1076 = breakpoint_here_p (step_resume_break_address
);
1077 if (breakpoints_inserted
)
1078 insert_step_breakpoint ();
1080 /* Subroutine call with source code we should not step over.
1081 Do step to the first line of code in it. */
1082 else if (step_over_calls
)
1084 SKIP_PROLOGUE (stop_func_start
);
1085 sal
= find_pc_line (stop_func_start
, 0);
1086 /* Use the step_resume_break to step until
1087 the end of the prologue, even if that involves jumps
1088 (as it seems to on the vax under 4.2). */
1089 /* If the prologue ends in the middle of a source line,
1090 continue to the end of that source line.
1091 Otherwise, just go to end of prologue. */
1092 #ifdef PROLOGUE_FIRSTLINE_OVERLAP
1093 /* no, don't either. It skips any code that's
1094 legitimately on the first line. */
1096 if (sal
.end
&& sal
.pc
!= stop_func_start
)
1097 stop_func_start
= sal
.end
;
1100 if (stop_func_start
== stop_pc
)
1102 /* We are already there: stop now. */
1107 /* Put the step-breakpoint there and go until there. */
1109 step_resume_break_address
= stop_func_start
;
1111 step_resume_break_duplicate
1112 = breakpoint_here_p (step_resume_break_address
);
1113 if (breakpoints_inserted
)
1114 insert_step_breakpoint ();
1115 /* Do not specify what the fp should be when we stop
1116 since on some machines the prologue
1117 is where the new fp value is established. */
1118 step_frame_address
= 0;
1119 /* And make sure stepping stops right away then. */
1120 step_range_end
= step_range_start
;
1125 /* We get here only if step_over_calls is 0 and we
1126 just stepped into a subroutine. I presume
1127 that step_over_calls is only 0 when we're
1128 supposed to be stepping at the assembly
1134 /* No subroutince call; stop now. */
1142 else if (trap_expected
1143 && IN_SIGTRAMP (stop_pc
, stop_func_name
)
1144 && !IN_SIGTRAMP (prev_pc
, prev_func_name
))
1146 /* What has happened here is that we have just stepped the inferior
1147 with a signal (because it is a signal which shouldn't make
1148 us stop), thus stepping into sigtramp.
1150 So we need to set a step_resume_break_address breakpoint
1151 and continue until we hit it, and then step. */
1152 step_resume_break_address
= prev_pc
;
1153 /* Always 1, I think, but it's probably easier to have
1154 the step_resume_break as usual rather than trying to
1155 re-use the breakpoint which is already there. */
1156 step_resume_break_duplicate
=
1157 breakpoint_here_p (step_resume_break_address
);
1158 if (breakpoints_inserted
)
1159 insert_step_breakpoint ();
1160 remove_breakpoints_on_following_step
= 1;
1164 /* Save the pc before execution, to compare with pc after stop. */
1165 prev_pc
= read_pc (); /* Might have been DECR_AFTER_BREAK */
1166 prev_func_start
= stop_func_start
; /* Ok, since if DECR_PC_AFTER
1167 BREAK is defined, the
1168 original pc would not have
1169 been at the start of a
1171 prev_func_name
= stop_func_name
;
1174 /* If we did not do break;, it means we should keep
1175 running the inferior and not return to debugger. */
1177 if (trap_expected
&& stop_signal
!= SIGTRAP
)
1179 /* We took a signal (which we are supposed to pass through to
1180 the inferior, else we'd have done a break above) and we
1181 haven't yet gotten our trap. Simply continue. */
1182 target_resume ((step_range_end
&& !step_resume_break_address
)
1183 || (trap_expected
&& !step_resume_break_address
)
1184 || bpstat_should_step (),
1189 /* Either the trap was not expected, but we are continuing
1190 anyway (the user asked that this signal be passed to the
1193 The signal was SIGTRAP, e.g. it was our signal, but we
1194 decided we should resume from it.
1196 We're going to run this baby now!
1198 Insert breakpoints now, unless we are trying
1199 to one-proceed past a breakpoint. */
1200 /* If we've just finished a special step resume and we don't
1201 want to hit a breakpoint, pull em out. */
1202 if (!step_resume_break_address
&&
1203 remove_breakpoints_on_following_step
)
1205 remove_breakpoints_on_following_step
= 0;
1206 remove_breakpoints ();
1207 breakpoints_inserted
= 0;
1209 else if (!breakpoints_inserted
&&
1210 (step_resume_break_address
!= NULL
|| !another_trap
))
1212 insert_step_breakpoint ();
1213 breakpoints_failed
= insert_breakpoints ();
1214 if (breakpoints_failed
)
1216 breakpoints_inserted
= 1;
1219 trap_expected
= another_trap
;
1221 if (stop_signal
== SIGTRAP
)
1224 #ifdef SHIFT_INST_REGS
1225 /* I'm not sure when this following segment applies. I do know, now,
1226 that we shouldn't rewrite the regs when we were stopped by a
1227 random signal from the inferior process. */
1229 if (!stop_breakpoint
&& (stop_signal
!= SIGCLD
)
1230 && !stopped_by_random_signal
)
1232 CORE_ADDR pc_contents
= read_register (PC_REGNUM
);
1233 CORE_ADDR npc_contents
= read_register (NPC_REGNUM
);
1234 if (pc_contents
!= npc_contents
)
1236 write_register (NNPC_REGNUM
, npc_contents
);
1237 write_register (NPC_REGNUM
, pc_contents
);
1240 #endif /* SHIFT_INST_REGS */
1242 target_resume ((step_range_end
&& !step_resume_break_address
)
1243 || (trap_expected
&& !step_resume_break_address
)
1244 || bpstat_should_step (),
1248 if (target_has_execution
)
1250 /* Assuming the inferior still exists, set these up for next
1251 time, just like we did above if we didn't break out of the
1253 prev_pc
= read_pc ();
1254 prev_func_start
= stop_func_start
;
1255 prev_func_name
= stop_func_name
;
1260 /* Here to return control to GDB when the inferior stops for real.
1261 Print appropriate messages, remove breakpoints, give terminal our modes.
1263 STOP_PRINT_FRAME nonzero means print the executing frame
1264 (pc, function, args, file, line number and line text).
1265 BREAKPOINTS_FAILED nonzero means stop was due to error
1266 attempting to insert breakpoints. */
1271 /* Make sure that the current_frame's pc is correct. This
1272 is a correction for setting up the frame info before doing
1273 DECR_PC_AFTER_BREAK */
1274 if (target_has_execution
)
1275 (get_current_frame ())->pc
= read_pc ();
1277 if (breakpoints_failed
)
1279 target_terminal_ours_for_output ();
1280 print_sys_errmsg ("ptrace", breakpoints_failed
);
1281 printf ("Stopped; cannot insert breakpoints.\n\
1282 The same program may be running in another process.\n");
1285 if (target_has_execution
)
1286 remove_step_breakpoint ();
1288 if (target_has_execution
&& breakpoints_inserted
)
1289 if (remove_breakpoints ())
1291 target_terminal_ours_for_output ();
1292 printf ("Cannot remove breakpoints because program is no longer writable.\n\
1293 It might be running in another process.\n\
1294 Further execution is probably impossible.\n");
1297 breakpoints_inserted
= 0;
1299 /* Delete the breakpoint we stopped at, if it wants to be deleted.
1300 Delete any breakpoint that is to be deleted at the next stop. */
1302 breakpoint_auto_delete (stop_bpstat
);
1304 /* If an auto-display called a function and that got a signal,
1305 delete that auto-display to avoid an infinite recursion. */
1307 if (stopped_by_random_signal
)
1308 disable_current_display ();
1310 if (step_multi
&& stop_step
)
1313 target_terminal_ours ();
1315 if (!target_has_stack
)
1318 /* Select innermost stack frame except on return from a stack dummy routine,
1319 or if the program has exited. */
1320 if (!stop_stack_dummy
)
1322 select_frame (get_current_frame (), 0);
1324 if (stop_print_frame
)
1326 int source_only
= bpstat_print (stop_bpstat
);
1330 && step_frame_address
== stop_frame_address
1331 && step_start_function
== find_pc_function (stop_pc
)));
1333 /* Display the auto-display expressions. */
1338 /* Save the function value return registers, if we care.
1339 We might be about to restore their previous contents. */
1340 if (proceed_to_finish
)
1341 read_register_bytes (0, stop_registers
, REGISTER_BYTES
);
1343 if (stop_stack_dummy
)
1345 /* Pop the empty frame that contains the stack dummy.
1346 POP_FRAME ends with a setting of the current frame, so we
1347 can use that next. */
1349 select_frame (get_current_frame (), 0);
1354 insert_step_breakpoint ()
1356 if (step_resume_break_address
&& !step_resume_break_duplicate
)
1357 target_insert_breakpoint (step_resume_break_address
,
1358 step_resume_break_shadow
);
1362 remove_step_breakpoint ()
1364 if (step_resume_break_address
&& !step_resume_break_duplicate
)
1365 target_remove_breakpoint (step_resume_break_address
,
1366 step_resume_break_shadow
);
1372 printf_filtered ("Signal\t\tStop\tPrint\tPass to program\tDescription\n");
1376 sig_print_info (number
)
1379 char *abbrev
= sig_abbrev(number
);
1381 printf_filtered ("%d\t\t", number
);
1383 printf_filtered ("SIG%s (%d)\t", abbrev
, number
);
1384 printf_filtered ("%s\t", signal_stop
[number
] ? "Yes" : "No");
1385 printf_filtered ("%s\t", signal_print
[number
] ? "Yes" : "No");
1386 printf_filtered ("%s\t\t", signal_program
[number
] ? "Yes" : "No");
1387 printf_filtered ("%s\n", sys_siglist
[number
]);
1390 /* Specify how various signals in the inferior should be handled. */
1393 handle_command (args
, from_tty
)
1397 register char *p
= args
;
1399 register int digits
, wordlen
;
1403 error_no_arg ("signal to handle");
1407 /* Find the end of the next word in the args. */
1409 p
[wordlen
] && p
[wordlen
] != ' ' && p
[wordlen
] != '\t';
1411 /* Set nextarg to the start of the word after the one we just
1412 found, and null-terminate this one. */
1413 if (p
[wordlen
] == '\0')
1414 nextarg
= p
+ wordlen
;
1418 nextarg
= p
+ wordlen
+ 1;
1422 for (digits
= 0; p
[digits
] >= '0' && p
[digits
] <= '9'; digits
++);
1426 /* It is the first argument--must be the signal to operate on. */
1427 if (digits
== wordlen
)
1431 if (signum
<= 0 || signum
>= NSIG
)
1434 error ("Invalid signal %s given as argument to \"handle\".", p
);
1440 signum
= sig_number (p
);
1442 error ("No such signal \"%s\"", p
);
1445 if (signum
== SIGTRAP
|| signum
== SIGINT
)
1447 if (!query ("SIG%s is used by the debugger.\nAre you sure you want to change it? ", sig_abbrev (signum
)))
1448 error ("Not confirmed.");
1451 /* Else, if already got a signal number, look for flag words
1452 saying what to do for it. */
1453 else if (!strncmp (p
, "stop", wordlen
))
1455 signal_stop
[signum
] = 1;
1456 signal_print
[signum
] = 1;
1458 else if (wordlen
>= 2 && !strncmp (p
, "print", wordlen
))
1459 signal_print
[signum
] = 1;
1460 else if (wordlen
>= 2 && !strncmp (p
, "pass", wordlen
))
1461 signal_program
[signum
] = 1;
1462 else if (!strncmp (p
, "ignore", wordlen
))
1463 signal_program
[signum
] = 0;
1464 else if (wordlen
>= 3 && !strncmp (p
, "nostop", wordlen
))
1465 signal_stop
[signum
] = 0;
1466 else if (wordlen
>= 4 && !strncmp (p
, "noprint", wordlen
))
1468 signal_print
[signum
] = 0;
1469 signal_stop
[signum
] = 0;
1471 else if (wordlen
>= 4 && !strncmp (p
, "nopass", wordlen
))
1472 signal_program
[signum
] = 0;
1473 else if (wordlen
>= 3 && !strncmp (p
, "noignore", wordlen
))
1474 signal_program
[signum
] = 1;
1475 /* Not a number and not a recognized flag word => complain. */
1478 error ("Unrecognized flag word: \"%s\".", p
);
1481 /* Find start of next word. */
1483 while (*p
== ' ' || *p
== '\t') p
++;
1488 /* Show the results. */
1489 sig_print_header ();
1490 sig_print_info (signum
);
1494 /* Print current contents of the tables set by the handle command. */
1497 signals_info (signum_exp
)
1501 sig_print_header ();
1505 /* First see if this is a symbol name. */
1506 i
= sig_number (signum_exp
);
1509 /* Nope, maybe it's an address which evaluates to a signal
1511 i
= parse_and_eval_address (signum_exp
);
1512 if (i
>= NSIG
|| i
< 0)
1513 error ("Signal number out of bounds.");
1519 printf_filtered ("\n");
1520 for (i
= 0; i
< NSIG
; i
++)
1527 printf_filtered ("\nUse the \"handle\" command to change these tables.\n");
1530 /* Save all of the information associated with the inferior<==>gdb
1531 connection. INF_STATUS is a pointer to a "struct inferior_status"
1532 (defined in inferior.h). */
1535 save_inferior_status (inf_status
, restore_stack_info
)
1536 struct inferior_status
*inf_status
;
1537 int restore_stack_info
;
1539 inf_status
->pc_changed
= pc_changed
;
1540 inf_status
->stop_signal
= stop_signal
;
1541 inf_status
->stop_pc
= stop_pc
;
1542 inf_status
->stop_frame_address
= stop_frame_address
;
1543 inf_status
->stop_step
= stop_step
;
1544 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
1545 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
1546 inf_status
->trap_expected
= trap_expected
;
1547 inf_status
->step_range_start
= step_range_start
;
1548 inf_status
->step_range_end
= step_range_end
;
1549 inf_status
->step_frame_address
= step_frame_address
;
1550 inf_status
->step_over_calls
= step_over_calls
;
1551 inf_status
->step_resume_break_address
= step_resume_break_address
;
1552 inf_status
->stop_after_trap
= stop_after_trap
;
1553 inf_status
->stop_soon_quietly
= stop_soon_quietly
;
1554 /* Save original bpstat chain here; replace it with copy of chain.
1555 If caller's caller is walking the chain, they'll be happier if we
1556 hand them back the original chain when restore_i_s is called. */
1557 inf_status
->stop_bpstat
= stop_bpstat
;
1558 stop_bpstat
= bpstat_copy (stop_bpstat
);
1559 inf_status
->breakpoint_proceeded
= breakpoint_proceeded
;
1560 inf_status
->restore_stack_info
= restore_stack_info
;
1561 inf_status
->proceed_to_finish
= proceed_to_finish
;
1563 bcopy (stop_registers
, inf_status
->stop_registers
, REGISTER_BYTES
);
1565 record_selected_frame (&(inf_status
->selected_frame_address
),
1566 &(inf_status
->selected_level
));
1571 restore_inferior_status (inf_status
)
1572 struct inferior_status
*inf_status
;
1575 int level
= inf_status
->selected_level
;
1577 pc_changed
= inf_status
->pc_changed
;
1578 stop_signal
= inf_status
->stop_signal
;
1579 stop_pc
= inf_status
->stop_pc
;
1580 stop_frame_address
= inf_status
->stop_frame_address
;
1581 stop_step
= inf_status
->stop_step
;
1582 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
1583 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
1584 trap_expected
= inf_status
->trap_expected
;
1585 step_range_start
= inf_status
->step_range_start
;
1586 step_range_end
= inf_status
->step_range_end
;
1587 step_frame_address
= inf_status
->step_frame_address
;
1588 step_over_calls
= inf_status
->step_over_calls
;
1589 step_resume_break_address
= inf_status
->step_resume_break_address
;
1590 stop_after_trap
= inf_status
->stop_after_trap
;
1591 stop_soon_quietly
= inf_status
->stop_soon_quietly
;
1592 bpstat_clear (&stop_bpstat
);
1593 stop_bpstat
= inf_status
->stop_bpstat
;
1594 breakpoint_proceeded
= inf_status
->breakpoint_proceeded
;
1595 proceed_to_finish
= inf_status
->proceed_to_finish
;
1597 bcopy (inf_status
->stop_registers
, stop_registers
, REGISTER_BYTES
);
1599 /* The inferior can be gone if the user types "print exit(0)"
1600 (and perhaps other times). */
1601 if (target_has_stack
&& inf_status
->restore_stack_info
)
1603 fid
= find_relative_frame (get_current_frame (),
1607 FRAME_FP (fid
) != inf_status
->selected_frame_address
||
1611 /* I'm not sure this error message is a good idea. I have
1612 only seen it occur after "Can't continue previously
1613 requested operation" (we get called from do_cleanups), in
1614 which case it just adds insult to injury (one confusing
1615 error message after another. Besides which, does the
1616 user really care if we can't restore the previously
1618 fprintf (stderr
, "Unable to restore previously selected frame.\n");
1620 select_frame (get_current_frame (), 0);
1624 select_frame (fid
, inf_status
->selected_level
);
1630 _initialize_infrun ()
1634 add_info ("signals", signals_info
,
1635 "What debugger does when program gets various signals.\n\
1636 Specify a signal number as argument to print info on that signal only.");
1638 add_com ("handle", class_run
, handle_command
,
1639 "Specify how to handle a signal.\n\
1640 Args are signal number followed by flags.\n\
1641 Flags allowed are \"stop\", \"print\", \"pass\",\n\
1642 \"nostop\", \"noprint\" or \"nopass\".\n\
1643 Print means print a message if this signal happens.\n\
1644 Stop means reenter debugger if this signal happens (implies print).\n\
1645 Pass means let program see this signal; otherwise program doesn't know.\n\
1646 Pass and Stop may be combined.");
1648 for (i
= 0; i
< NSIG
; i
++)
1651 signal_print
[i
] = 1;
1652 signal_program
[i
] = 1;
1655 /* Signals caused by debugger's own actions
1656 should not be given to the program afterwards. */
1657 signal_program
[SIGTRAP
] = 0;
1658 signal_program
[SIGINT
] = 0;
1660 /* Signals that are not errors should not normally enter the debugger. */
1662 signal_stop
[SIGALRM
] = 0;
1663 signal_print
[SIGALRM
] = 0;
1664 #endif /* SIGALRM */
1666 signal_stop
[SIGVTALRM
] = 0;
1667 signal_print
[SIGVTALRM
] = 0;
1668 #endif /* SIGVTALRM */
1670 signal_stop
[SIGPROF
] = 0;
1671 signal_print
[SIGPROF
] = 0;
1672 #endif /* SIGPROF */
1674 signal_stop
[SIGCHLD
] = 0;
1675 signal_print
[SIGCHLD
] = 0;
1676 #endif /* SIGCHLD */
1678 signal_stop
[SIGCLD
] = 0;
1679 signal_print
[SIGCLD
] = 0;
1682 signal_stop
[SIGIO
] = 0;
1683 signal_print
[SIGIO
] = 0;
1686 signal_stop
[SIGURG
] = 0;
1687 signal_print
[SIGURG
] = 0;