diff options
Diffstat (limited to 'gdb/infrun.c')
| -rw-r--r-- | gdb/infrun.c | 260 |
1 files changed, 123 insertions, 137 deletions
diff --git a/gdb/infrun.c b/gdb/infrun.c index f8bc976..07083f0 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -99,26 +99,10 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ 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. - -#if 0 - We skip this; it causes more problems than it's worth. -#ifdef SUN4_COMPILER_FEATURE - We do a special ifdef for the sun 4, forcing it to single step - into calls which don't have prologues. This means that we can't - nexti over leaf nodes, we can probably next over them (since they - won't have debugging symbols, usually), and we can next out of - functions returning structures (with a "call .stret4" at the end). -#endif -#endif */ - - - - -#include <stdio.h> -#include <string.h> #include "defs.h" +#include <string.h> #include "symtab.h" #include "frame.h" #include "inferior.h" @@ -199,6 +183,21 @@ extern struct target_ops child_ops; /* In inftarg.c */ #define GET_LONGJMP_TARGET(PC_ADDR) 0 #endif + +/* Some machines have trampoline code that sits between function callers + and the actual functions themselves. If this machine doesn't have + such things, disable their processing. */ +#ifndef SKIP_TRAMPOLINE_CODE +#define SKIP_TRAMPOLINE_CODE(pc) 0 +#endif + + +#ifdef TDESC +#include "tdesc.h" +int safe_to_init_tdesc_context = 0; +extern dc_dcontext_t current_context; +#endif + /* Tables of how to react to signals; the user sets them. */ static char signal_stop[NSIG]; @@ -434,21 +433,6 @@ The same program may be running in another process."); normal_stop (); } -#if 0 -/* This might be useful (not sure), but isn't currently used. See also - write_pc(). */ -/* Writing the inferior pc as a register calls this function - to inform infrun that the pc has been set in the debugger. */ - -void -writing_pc (val) - CORE_ADDR val; -{ - stop_pc = val; - pc_changed = 1; -} -#endif - /* Record the pc and sp of the program the last time it stopped. These are just used internally by wait_for_inferior, but need to be preserved over calls to it and cleared when the inferior @@ -788,7 +772,7 @@ wait_for_inferior () CORE_ADDR stop_sp; CORE_ADDR stop_func_start; char *stop_func_name; - CORE_ADDR prologue_pc; + CORE_ADDR prologue_pc, tmp; int stop_step_resume_break; struct symtab_and_line sal; int remove_breakpoints_on_following_step = 0; @@ -975,8 +959,7 @@ wait_for_inferior () /* End of a stack dummy. Some systems (e.g. Sony news) give another signal besides SIGTRAP, so check here as well as above. */ - || (stop_sp INNER_THAN stop_pc - && stop_pc INNER_THAN stop_frame_address) + || PC_IN_CALL_DUMMY (stop_pc, stop_sp, stop_frame_address) ); if (!random_signal) stop_signal = SIGTRAP; @@ -1181,19 +1164,7 @@ wait_for_inferior () && (stop_sp INNER_THAN prev_sp || stop_frame_address != step_frame_address))) { -#if 0 - /* When "next"ing through a function, - This causes an extra stop at the end. - Is there any reason for this? - It's confusing to the user. */ - /* Don't step through the return from a function - unless that is the first instruction stepped through. */ - if (ABOUT_TO_RETURN (stop_pc)) - { - stop_step = 1; - break; - } -#endif + ; } /* We stepped out of the stepping range. See if that was due @@ -1225,118 +1196,132 @@ wait_for_inferior () if (step_range_end == 1) step_range_end = (step_range_start = prev_pc) + 1; remove_breakpoints_on_following_step = 1; + goto save_pc; } /* ==> See comments at top of file on this algorithm. <==*/ - else if (stop_pc == stop_func_start + if (stop_pc == stop_func_start && (stop_func_start != prev_func_start || prologue_pc != stop_func_start || stop_sp != prev_sp)) { - /* It's a subroutine call */ - if (step_over_calls > 0 - || (step_over_calls && find_pc_function (stop_pc) == 0)) + /* It's a subroutine call. + (0) If we are not stepping over any calls ("stepi"), we + just stop. + (1) If we're doing a "next", we want to continue through + the call ("step over the call"). + (2) If we are in a function-call trampoline (a stub between + the calling routine and the real function), locate + the real function and change stop_func_start. + (3) If we're doing a "step", and there are no debug symbols + at the target of the call, we want to continue through + it ("step over the call"). + (4) Otherwise, we want to stop soon, after the function + prologue ("step into the call"). */ + + if (step_over_calls == 0) { - /* A subroutine call has happened. */ - /* Set a special breakpoint after the return */ + /* I presume that step_over_calls is only 0 when we're + supposed to be stepping at the assembly language level. */ + stop_step = 1; + break; + } - step_resume_break_address = - ADDR_BITS_REMOVE ( - SAVED_PC_AFTER_CALL ( - get_current_frame ())); + if (step_over_calls > 0) + goto step_over_function; - step_resume_break_duplicate - = breakpoint_here_p (step_resume_break_address); - if (breakpoints_inserted) - insert_step_breakpoint (); - } + tmp = SKIP_TRAMPOLINE_CODE (stop_pc); + if (tmp != NULL) + stop_func_start = tmp; + + if (find_pc_function (stop_func_start) != 0) + goto step_into_function; + +step_over_function: + /* A subroutine call has happened. */ + /* Set a special breakpoint after the return */ + step_resume_break_address = + ADDR_BITS_REMOVE + (SAVED_PC_AFTER_CALL (get_current_frame ())); + step_resume_break_duplicate + = breakpoint_here_p (step_resume_break_address); + if (breakpoints_inserted) + insert_step_breakpoint (); + goto save_pc; + +step_into_function: /* Subroutine call with source code we should not step over. Do step to the first line of code in it. */ - else if (step_over_calls) - { - SKIP_PROLOGUE (stop_func_start); - sal = find_pc_line (stop_func_start, 0); - /* Use the step_resume_break to step until - the end of the prologue, even if that involves jumps - (as it seems to on the vax under 4.2). */ - /* If the prologue ends in the middle of a source line, - continue to the end of that source line. - Otherwise, just go to end of prologue. */ + SKIP_PROLOGUE (stop_func_start); + sal = find_pc_line (stop_func_start, 0); + /* Use the step_resume_break to step until + the end of the prologue, even if that involves jumps + (as it seems to on the vax under 4.2). */ + /* If the prologue ends in the middle of a source line, + continue to the end of that source line. + Otherwise, just go to end of prologue. */ #ifdef PROLOGUE_FIRSTLINE_OVERLAP - /* no, don't either. It skips any code that's - legitimately on the first line. */ + /* no, don't either. It skips any code that's + legitimately on the first line. */ #else - if (sal.end && sal.pc != stop_func_start) - stop_func_start = sal.end; + if (sal.end && sal.pc != stop_func_start) + stop_func_start = sal.end; #endif - - if (stop_func_start == stop_pc) - { - /* We are already there: stop now. */ - stop_step = 1; - break; - } - else - /* Put the step-breakpoint there and go until there. */ - { - step_resume_break_address = stop_func_start; - - step_resume_break_duplicate - = breakpoint_here_p (step_resume_break_address); - if (breakpoints_inserted) - insert_step_breakpoint (); - /* Do not specify what the fp should be when we stop - since on some machines the prologue - is where the new fp value is established. */ - step_frame_address = 0; - /* And make sure stepping stops right away then. */ - step_range_end = step_range_start; - } - } - else - { - /* We get here only if step_over_calls is 0 and we - just stepped into a subroutine. I presume - that step_over_calls is only 0 when we're - supposed to be stepping at the assembly - language level.*/ - stop_step = 1; - break; - } - } - /* No subroutine call; stop now. */ - else - { - /* We've wandered out of the step range (but we haven't done a - subroutine call or return (that's handled elsewhere)). We - don't really want to stop until we encounter the start of a - new statement. If so, we stop. Otherwise, we reset - step_range_start and step_range_end, and just continue. */ - sal = find_pc_line(stop_pc, 0); - - if (step_range_end == 1 /* Don't do this for stepi/nexti */ - || sal.line == 0 /* Stop now if no line # info */ - || (current_line != sal.line - && stop_pc == sal.pc)) + + if (stop_func_start == stop_pc) { + /* We are already there: stop now. */ stop_step = 1; break; - } - else if (sal.line != 0) + } + else + /* Put the step-breakpoint there and go until there. */ { - /* This is probably not necessary, but it probably makes - 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; + step_resume_break_address = stop_func_start; + + step_resume_break_duplicate + = breakpoint_here_p (step_resume_break_address); + if (breakpoints_inserted) + insert_step_breakpoint (); + /* Do not specify what the fp should be when we stop + since on some machines the prologue + is where the new fp value is established. */ + step_frame_address = 0; + /* And make sure stepping stops right away then. */ + step_range_end = step_range_start; } + goto save_pc; } + + /* We've wandered out of the step range (but haven't done a + subroutine call or return). */ + + sal = find_pc_line(stop_pc, 0); + + if (step_range_end == 1 || /* stepi or nexti */ + sal.line == 0 || /* ...or no line # info */ + (stop_pc == sal.pc /* ...or we're at the start */ + && current_line != sal.line)) { /* of a different line */ + /* Stop because we're done stepping. */ + stop_step = 1; + break; + } else { + /* We aren't done stepping, and we have line number info for $pc. + Optimize by setting the step_range for the line. + (We might not be in the original line, but if we entered a + new line in mid-statement, we continue stepping. This makes + things like for(;;) statements work better.) */ + step_range_start = sal.pc; + step_range_end = sal.end; + goto save_pc; + } + abort(); /* We never fall through here */ } - else if (trap_expected - && IN_SIGTRAMP (stop_pc, stop_func_name) - && !IN_SIGTRAMP (prev_pc, prev_func_name)) + if (trap_expected + && IN_SIGTRAMP (stop_pc, stop_func_name) + && !IN_SIGTRAMP (prev_pc, prev_func_name)) { /* What has happened here is that we have just stepped the inferior with a signal (because it is a signal which shouldn't make @@ -1363,6 +1348,7 @@ wait_for_inferior () keep_going: +save_pc: /* Save the pc before execution, to compare with pc after stop. */ prev_pc = read_pc (); /* Might have been DECR_AFTER_BREAK */ prev_func_start = stop_func_start; /* Ok, since if DECR_PC_AFTER @@ -1821,7 +1807,7 @@ restore_inferior_status (inf_status) FRAME_FP (fid) != inf_status->selected_frame_address || level != 0) { -#if 0 +#if 1 /* I'm not sure this error message is a good idea. I have only seen it occur after "Can't continue previously requested operation" (we get called from do_cleanups), in |