along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
-/* Notes on the algorithm used in wait_for_inferior to determine if we
- just did a subroutine call when stepping. We have the following
- information at that point:
-
- Current and previous (just before this step) pc.
- Current and previous sp.
- Current and previous start of current function.
-
- If the starts of the functions don't match, then
-
- a) We did a subroutine call.
-
- In this case, the pc will be at the beginning of a function.
-
- b) We did a subroutine return.
-
- Otherwise.
-
- c) We did a longjmp.
-
- If we did a longjump, we were doing "nexti", since a next would
- have attempted to skip over the assembly language routine in which
- the longjmp is coded and would have simply been the equivalent of a
- continue. I consider this ok behaivior. We'd like one of two
- things to happen if we are doing a nexti through the longjmp()
- routine: 1) It behaves as a stepi, or 2) It acts like a continue as
- above. Given that this is a special case, and that anybody who
- thinks that the concept of sub calls is meaningful in the context
- of a longjmp, I'll take either one. Let's see what happens.
-
- Acts like a subroutine return. I can handle that with no problem
- at all.
-
- -->So: If the current and previous beginnings of the current
- function don't match, *and* the pc is at the start of a function,
- we've done a subroutine call. If the pc is not at the start of a
- function, we *didn't* do a subroutine call.
-
- -->If the beginnings of the current and previous function do match,
- either:
-
- a) We just did a recursive call.
-
- In this case, we would be at the very beginning of a
- function and 1) it will have a prologue (don't jump to
- before prologue, or 2) (we assume here that it doesn't have
- a prologue) there will have been a change in the stack
- pointer over the last instruction. (Ie. it's got to put
- the saved pc somewhere. The stack is the usual place. In
- a recursive call a register is only an option if there's a
- prologue to do something with it. This is even true on
- register window machines; the prologue sets up the new
- window. It might not be true on a register window machine
- where the call instruction moved the register window
- itself. Hmmm. One would hope that the stack pointer would
- also change. If it doesn't, somebody send me a note, and
- I'll work out a more general theory.
- so) on all machines I'm aware of:
-
- m68k: Call changes stack pointer. Regular jumps don't.
-
- sparc: Recursive calls must have frames and therefor,
- prologues.
-
- vax: All calls have frames and hence change the
- stack pointer.
-
- b) We did a return from a recursive call. I don't see that we
- have either the ability or the need to distinguish this
- from an ordinary jump. The stack frame will be printed
- when and if the frame pointer changes; if we are in a
- function without a frame pointer, it's the users own
- lookout.
-
- c) We did a jump within a function. We assume that this is
- true if we didn't do a recursive call.
-
- d) We are in no-man's land ("I see no symbols here"). We
- don't worry about this; it will make calls look like simple
- jumps (and the stack frames will be printed when the frame
- pointer moves), which is a reasonably non-violent response.
-*/
-
#include "defs.h"
#include <string.h>
#include <ctype.h>
#include "gdbcore.h"
#include "gdbcmd.h"
#include "target.h"
+#include "thread.h"
#include <signal.h>
#define SKIP_TRAMPOLINE_CODE(pc) 0
#endif
+/* On Irix 5, some function calls automatically skip the first few
+ instructions, so we need a more complicated test to see if we are
+ the start of a function. */
+#ifndef AT_FUNCTION_START
+#define AT_FUNCTION_START(pc,func_name,func_addr) 0
+#endif
+
/* For SVR4 shared libraries, each call goes through a small piece of
trampoline code in the ".init" section. IN_SOLIB_TRAMPOLINE evaluates
to nonzero if we are current stopped in one of these. */
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
QUIT;
+#ifdef CANNOT_STEP_BREAKPOINT
+ /* Most targets can step a breakpoint instruction, thus executing it
+ normally. But if this one cannot, just continue and we will hit
+ it anyway. */
+ if (step && breakpoints_inserted && breakpoint_here_p (read_pc ()))
+ step = 0;
+#endif
+
#ifdef NO_SINGLE_STEP
if (step) {
single_step(sig); /* Do it the hard way, w/temp breakpoints */
DO_DEFERRED_STORES;
#endif
- target_resume (inferior_pid, step, sig);
+ /* Install inferior's terminal modes. */
+ target_terminal_inferior ();
+
+ target_resume (-1, step, sig);
discard_cleanups (old_cleanups);
}
breakpoints_inserted = 1;
}
- /* Install inferior's terminal modes. */
- target_terminal_inferior ();
-
if (siggnal >= 0)
stop_signal = siggnal;
/* If this signal should not be seen by program,
trap_expected_after_continue = 0;
breakpoints_inserted = 0;
- mark_breakpoints_out ();
+ breakpoint_init_inferior ();
stop_signal = 0; /* Don't confuse first call to proceed(). */
}
struct symtab_and_line sal;
int remove_breakpoints_on_following_step = 0;
int current_line;
+ struct symtab *current_symtab;
int handling_longjmp = 0; /* FIXME */
struct breakpoint *step_resume_breakpoint = NULL;
int pid;
&step_resume_breakpoint);
sal = find_pc_line(prev_pc, 0);
current_line = sal.line;
+ current_symtab = sal.symtab;
/* Are we stepping? */
#define CURRENTLY_STEPPING() ((step_resume_breakpoint == NULL \
flush_cached_frames ();
registers_changed ();
- pid = target_wait (&w);
+ pid = target_wait (-1, &w);
#ifdef SIGTRAP_STOP_AFTER_LOAD
else
if (!batch_mode())
printf_filtered ("\nProgram exited normally.\n");
- fflush (stdout);
+ gdb_flush (gdb_stdout);
target_mourn_inferior ();
#ifdef NO_SINGLE_STEP
one_stepped = 0;
printf_filtered (", %s\n", safe_strsignal (stop_signal));
#endif
printf_filtered ("The program no longer exists.\n");
- fflush (stdout);
+ gdb_flush (gdb_stdout);
#ifdef NO_SINGLE_STEP
one_stepped = 0;
#endif
break;
}
-
+
+ stop_signal = WSTOPSIG (w);
+
+ if (pid != inferior_pid)
+ {
+ int save_pid = inferior_pid;
+
+ inferior_pid = pid; /* Setup for target memory/regs */
+ registers_changed ();
+ stop_pc = read_pc ();
+ inferior_pid = save_pid;
+ registers_changed ();
+ }
+ else
+ stop_pc = read_pc ();
+
+ if (stop_signal == SIGTRAP
+ && breakpoint_here_p (stop_pc - DECR_PC_AFTER_BREAK))
+ {
+ if (!breakpoint_thread_match (stop_pc - DECR_PC_AFTER_BREAK, pid))
+ {
+ /* Saw a breakpoint, but it was hit by the wrong thread. Just continue. */
+ if (breakpoints_inserted)
+ {
+ if (pid != inferior_pid)
+ {
+ int save_pid = inferior_pid;
+
+ inferior_pid = pid;
+ registers_changed ();
+ write_pc (stop_pc - DECR_PC_AFTER_BREAK);
+ inferior_pid = save_pid;
+ registers_changed ();
+ }
+ else
+ write_pc (stop_pc - DECR_PC_AFTER_BREAK);
+
+ remove_breakpoints ();
+ target_resume (pid, 1, 0); /* Single step */
+ /* FIXME: What if a signal arrives instead of the single-step
+ happening? */
+ target_wait (pid, &w);
+ insert_breakpoints ();
+ }
+ target_resume (-1, 0, 0);
+ continue;
+ }
+ else
+ if (pid != inferior_pid)
+ goto switch_thread;
+ }
+
if (pid != inferior_pid)
{
int printed = 0;
if (!in_thread_list (pid))
{
- fprintf (stderr, "[New %s]\n", target_pid_to_str (pid));
+ fprintf_unfiltered (gdb_stderr, "[New %s]\n", target_pid_to_str (pid));
add_thread (pid);
- target_resume (pid, 0, 0);
+ target_resume (-1, 0, 0);
continue;
}
else
{
- stop_signal = WSTOPSIG (w);
-
if (stop_signal >= NSIG || signal_print[stop_signal])
{
char *signame;
printf_filtered ("%s (%d)", signame, stop_signal);
printf_filtered (", %s\n", safe_strsignal (stop_signal));
- fflush (stdout);
+ gdb_flush (gdb_stdout);
}
- if (stop_signal >= NSIG || signal_stop[stop_signal])
+ if (stop_signal == SIGTRAP
+ || stop_signal >= NSIG
+ || signal_stop[stop_signal])
{
+switch_thread:
inferior_pid = pid;
printf_filtered ("[Switching to %s]\n", target_pid_to_str (pid));
continue;
}
- stop_pc = read_pc ();
set_current_frame ( create_new_frame (read_fp (), stop_pc));
stop_frame_address = FRAME_FP (get_current_frame ());
/* Don't care about return value; stop_func_start and stop_func_name
will both be 0 if it doesn't work. */
find_pc_partial_function (stop_pc, &stop_func_name, &stop_func_start,
- (CORE_ADDR *)NULL);
+ NULL);
stop_func_start += FUNCTION_START_OFFSET;
another_trap = 0;
bpstat_clear (&stop_bpstat);
3) set random_signal to 1, and the decision between 1 and 2
will be made according to the signal handling tables. */
- stop_signal = WSTOPSIG (w);
-
/* First, distinguish signals caused by the debugger from signals
that have to do with the program's own actions.
Note that breakpoint insns may cause SIGTRAP or SIGILL
printf_filtered ("%s (%d)", signame, stop_signal);
printf_filtered (", %s\n", safe_strsignal (stop_signal));
#endif /* PRINT_RANDOM_SIGNAL */
- fflush (stdout);
+ gdb_flush (gdb_stdout);
}
if (stop_signal >= NSIG
|| signal_stop[stop_signal])
cleanup chain, so no need to worry about it here. */
goto stop_stepping;
+ case BPSTAT_WHAT_LAST:
+ /* Not a real code, but listed here to shut up gcc -Wall. */
+
case BPSTAT_WHAT_KEEP_CHECKING:
break;
}
SKIP_PROLOGUE (prologue_pc);
}
- /* ==> See comments at top of file on this algorithm. <==*/
+ if ((/* Might be a non-recursive call. If the symbols are missing
+ enough that stop_func_start == prev_func_start even though
+ they are really two functions, we will treat some calls as
+ jumps. */
+ stop_func_start != prev_func_start
+
+ /* Might be a recursive call if either we have a prologue
+ or the call instruction itself saves the PC on the stack. */
+ || prologue_pc != stop_func_start
+ || stop_sp != prev_sp)
+ && (/* PC is completely out of bounds of any known objfiles. Treat
+ like a subroutine call. */
+ ! stop_func_start
+
+ /* If we do a call, we will be at the start of a function... */
+ || stop_pc == stop_func_start
+#if 0
+ /* Should be taken care of by the stop_pc < prologue_pc check
+ below. Also, on irix5 where this checks for stop_pc
+ equal to stop_func_start plus 12, it would seem to be
+ wrong for a function with a 4 byte prologue, and an 8 byte
+ call; a "return" could end up at stop_func_start+12. */
+
+ || AT_FUNCTION_START (stop_pc, stop_func_name, stop_func_start)
+#endif
- if ((stop_pc == stop_func_start
- || IN_SOLIB_TRAMPOLINE (stop_pc, stop_func_name))
- && (stop_func_start != prev_func_start
- || prologue_pc != stop_func_start
- || stop_sp != prev_sp))
+ /* ...except on the Alpha with -O (and also Irix 5 and
+ perhaps others), in which we might call the address
+ after the load of gp. Since prologues don't contain
+ calls, we can't return to within one, and we don't
+ jump back into them, so this check is OK. */
+
+ || stop_pc < prologue_pc
+
+ /* If we end up in certain places, it means we did a subroutine
+ call. I'm not completely sure this is necessary now that we
+ have the above checks with stop_func_start (and now that
+ find_pc_partial_function is pickier). */
+ || IN_SOLIB_TRAMPOLINE (stop_pc, stop_func_name)
+
+ /* If none of the above apply, it is a jump within a function,
+ or a return from a subroutine. The other case is longjmp,
+ which can no longer happen here as long as the
+ handling_longjmp stuff is working. */
+ ))
{
/* It's a subroutine call. */
goto keep_going;
}
- /* We've wandered out of the step range (but haven't done a
- subroutine call or return). (Is that true? I think we get
- here if we did a return and maybe a longjmp). */
+ /* We've wandered out of the step range. */
sal = find_pc_line(stop_pc, 0);
break;
}
- if (stop_pc == sal.pc && current_line != sal.line)
+ if (stop_pc == sal.pc
+ && (current_line != sal.line || current_symtab != sal.symtab))
{
/* We are at the start of a different line. So stop. Note that
we don't stop if we step into the middle of a different line.
/* I'm not sure when this following segment applies. I do know, now,
that we shouldn't rewrite the regs when we were stopped by a
random signal from the inferior process. */
+ /* FIXME: Shouldn't this be based on the valid bit of the SXIP?
+ (this is only used on the 88k). */
if (!bpstat_explains_signal (stop_bpstat)
&& (stop_signal != SIGCLD)
&& !stopped_by_random_signal)
- {
- CORE_ADDR pc_contents = read_register (PC_REGNUM);
- CORE_ADDR npc_contents = read_register (NPC_REGNUM);
- if (pc_contents != npc_contents)
- {
- write_register (NNPC_REGNUM, npc_contents);
- write_register (NPC_REGNUM, pc_contents);
- }
- }
+ SHIFT_INST_REGS();
#endif /* SHIFT_INST_REGS */
resume (CURRENTLY_STEPPING (), stop_signal);
/* Make sure that the current_frame's pc is correct. This
is a correction for setting up the frame info before doing
DECR_PC_AFTER_BREAK */
- if (target_has_execution)
+ if (target_has_execution && get_current_frame())
(get_current_frame ())->pc = read_pc ();
if (breakpoints_failed)
}
else
{
- printf ("Not confirmed, unchanged.\n");
- fflush (stdout);
+ printf_unfiltered ("Not confirmed, unchanged.\n");
+ gdb_flush (gdb_stdout);
}
}
break;
argv++;
}
- target_notice_signals();
+ target_notice_signals(inferior_pid);
if (from_tty)
{
projects / binutils.git / blobdiff