diff options
Diffstat (limited to 'gdb/infrun.c')
| -rw-r--r-- | gdb/infrun.c | 1444 |
1 files changed, 0 insertions, 1444 deletions
diff --git a/gdb/infrun.c b/gdb/infrun.c deleted file mode 100644 index c930da0..0000000 --- a/gdb/infrun.c +++ /dev/null @@ -1,1444 +0,0 @@ -/* Start and stop the inferior process, for GDB. - Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc. - -This file is part of GDB. - -GDB is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 1, or (at your option) -any later version. - -GDB is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GDB; see the file COPYING. If not, write to -the Free Software Foundation, 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 start's 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. - randy@wheaties.ai.mit.edu). This is true (albeit slipperly - 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. - -#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 "defs.h" -#include "param.h" -#include "symtab.h" -#include "frame.h" -#include "inferior.h" -#include "wait.h" - -#include <signal.h> - -/* unistd.h is needed to #define X_OK */ -#ifdef USG -#include <unistd.h> -#else -#include <sys/file.h> -#endif - -#ifdef UMAX_PTRACE -#include <aouthdr.h> -#include <sys/param.h> -#include <sys/ptrace.h> -#endif /* UMAX_PTRACE */ - -/* Required by <sys/user.h>. */ -#include <sys/types.h> -/* Required by <sys/user.h>, at least on system V. */ -#include <sys/dir.h> -/* Needed by IN_SIGTRAMP on some machines (e.g. vax). */ -#include <sys/param.h> -/* Needed by IN_SIGTRAMP on some machines (e.g. vax). */ -#include <sys/user.h> - -extern char *sys_siglist[]; -extern int errno; - -/* Sigtramp is a routine that the kernel calls (which then calls the - signal handler). On most machines it is a library routine that - is linked into the executable. - - This macro, given a program counter value and the name of the - function in which that PC resides (which can be null if the - name is not known), returns nonzero if the PC and name show - that we are in sigtramp. - - On most machines just see if the name is sigtramp (and if we have - no name, assume we are not in sigtramp). */ -#if !defined (IN_SIGTRAMP) -#define IN_SIGTRAMP(pc, name) \ - name && !strcmp ("_sigtramp", name) -#endif - -/* Tables of how to react to signals; the user sets them. */ - -static char signal_stop[NSIG]; -static char signal_print[NSIG]; -static char signal_program[NSIG]; - -/* Nonzero if breakpoints are now inserted in the inferior. */ - -static int breakpoints_inserted; - -/* Function inferior was in as of last step command. */ - -static struct symbol *step_start_function; - -/* This is the sequence of bytes we insert for a breakpoint. */ - -static char break_insn[] = BREAKPOINT; - -/* Nonzero => address for special breakpoint for resuming stepping. */ - -static CORE_ADDR step_resume_break_address; - -/* Original contents of the byte where the special breakpoint is. */ - -static char step_resume_break_shadow[sizeof break_insn]; - -/* Nonzero means the special breakpoint is a duplicate - so it has not itself been inserted. */ - -static int step_resume_break_duplicate; - -/* Nonzero if we are expecting a trace trap and should proceed from it. - 2 means expecting 2 trace traps and should continue both times. - That occurs when we tell sh to exec the program: we will get - a trap after the exec of sh and a second when the program is exec'd. */ - -static int trap_expected; - -/* Nonzero if the next time we try to continue the inferior, it will - step one instruction and generate a spurious trace trap. - This is used to compensate for a bug in HP-UX. */ - -static int trap_expected_after_continue; - -/* Nonzero means expecting a trace trap - and should stop the inferior and return silently when it happens. */ - -int stop_after_trap; - -/* Nonzero means expecting a trace trap due to attaching to a process. */ - -int stop_after_attach; - -/* Nonzero if pc has been changed by the debugger - since the inferior stopped. */ - -int pc_changed; - -/* Nonzero if debugging a remote machine via a serial link or ethernet. */ - -int remote_debugging; - -/* Save register contents here when about to pop a stack dummy frame. */ - -char stop_registers[REGISTER_BYTES]; - -/* Nonzero if program stopped due to error trying to insert breakpoints. */ - -static int breakpoints_failed; - -/* Nonzero if inferior is in sh before our program got exec'd. */ - -static int running_in_shell; - -/* Nonzero after stop if current stack frame should be printed. */ - -static int stop_print_frame; - -#ifdef NO_SINGLE_STEP -extern int one_stepped; /* From machine dependent code */ -extern void single_step (); /* Same. */ -#endif /* NO_SINGLE_STEP */ - -static void insert_step_breakpoint (); -static void remove_step_breakpoint (); -static void wait_for_inferior (); -static void normal_stop (); - - -/* Clear out all variables saying what to do when inferior is continued. - First do this, then set the ones you want, then call `proceed'. */ - -void -clear_proceed_status () -{ - trap_expected = 0; - step_range_start = 0; - step_range_end = 0; - step_frame_address = 0; - step_over_calls = -1; - step_resume_break_address = 0; - stop_after_trap = 0; - stop_after_attach = 0; - - /* Discard any remaining commands left by breakpoint we had stopped at. */ - clear_breakpoint_commands (); -} - -/* Basic routine for continuing the program in various fashions. - - ADDR is the address to resume at, or -1 for resume where stopped. - SIGNAL is the signal to give it, or 0 for none, - or -1 for act according to how it stopped. - STEP is nonzero if should trap after one instruction. - -1 means return after that and print nothing. - You should probably set various step_... variables - before calling here, if you are stepping. - - You should call clear_proceed_status before calling proceed. */ - -void -proceed (addr, signal, step) - CORE_ADDR addr; - int signal; - int step; -{ - int oneproc = 0; - - if (step > 0) - step_start_function = find_pc_function (read_pc ()); - if (step < 0) - stop_after_trap = 1; - - if (addr == -1) - { - /* If there is a breakpoint at the address we will resume at, - step one instruction before inserting breakpoints - so that we do not stop right away. */ - - if (!pc_changed && breakpoint_here_p (read_pc ())) - oneproc = 1; - } - else - { - write_register (PC_REGNUM, addr); -#ifdef NPC_REGNUM - write_register (NPC_REGNUM, addr + 4); -#endif - } - - if (trap_expected_after_continue) - { - /* If (step == 0), a trap will be automatically generated after - the first instruction is executed. Force step one - instruction to clear this condition. This should not occur - if step is nonzero, but it is harmless in that case. */ - oneproc = 1; - trap_expected_after_continue = 0; - } - - if (oneproc) - /* We will get a trace trap after one instruction. - Continue it automatically and insert breakpoints then. */ - trap_expected = 1; - else - { - int temp = insert_breakpoints (); - if (temp) - { - print_sys_errmsg ("ptrace", temp); - error ("Cannot insert breakpoints.\n\ -The same program may be running in another process."); - } - breakpoints_inserted = 1; - } - - /* Install inferior's terminal modes. */ - terminal_inferior (); - - if (signal >= 0) - stop_signal = signal; - /* If this signal should not be seen by program, - give it zero. Used for debugging signals. */ - else if (stop_signal < NSIG && !signal_program[stop_signal]) - stop_signal= 0; - - /* Resume inferior. */ - resume (oneproc || step, stop_signal); - - /* Wait for it to stop (if not standalone) - and in any case decode why it stopped, and act accordingly. */ - - wait_for_inferior (); - normal_stop (); -} - -/* 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; -} - -/* Start an inferior process for the first time. - Actually it was started by the fork that created it, - but it will have stopped one instruction after execing sh. - Here we must get it up to actual execution of the real program. */ - -void -start_inferior () -{ - /* We will get a trace trap after one instruction. - Continue it automatically. Eventually (after shell does an exec) - it will get another trace trap. Then insert breakpoints and continue. */ - -#ifdef START_INFERIOR_TRAPS_EXPECTED - trap_expected = START_INFERIOR_TRAPS_EXPECTED; -#else - trap_expected = 2; -#endif - - running_in_shell = 0; /* Set to 1 at first SIGTRAP, 0 at second. */ - trap_expected_after_continue = 0; - breakpoints_inserted = 0; - mark_breakpoints_out (); - - /* Set up the "saved terminal modes" of the inferior - based on what modes we are starting it with. */ - terminal_init_inferior (); - - /* Install inferior's terminal modes. */ - terminal_inferior (); - - if (remote_debugging) - { - trap_expected = 0; - fetch_inferior_registers(); - set_current_frame (create_new_frame (read_register (FP_REGNUM), - read_pc ())); - stop_frame_address = FRAME_FP (get_current_frame()); - inferior_pid = 3; - if (insert_breakpoints()) - fatal("Can't insert breakpoints"); - breakpoints_inserted = 1; - proceed(-1, -1, 0); - } - else - { - wait_for_inferior (); - normal_stop (); - } -} - -/* Start remote-debugging of a machine over a serial link. */ - -void -start_remote () -{ - clear_proceed_status (); - running_in_shell = 0; - trap_expected = 0; - inferior_pid = 3; - breakpoints_inserted = 0; - mark_breakpoints_out (); - wait_for_inferior (); - normal_stop(); -} - -#ifdef ATTACH_DETACH - -/* Attach to process PID, then initialize for debugging it - and wait for the trace-trap that results from attaching. */ - -void -attach_program (pid) - int pid; -{ - attach (pid); - inferior_pid = pid; - - mark_breakpoints_out (); - terminal_init_inferior (); - clear_proceed_status (); - stop_after_attach = 1; - /*proceed (-1, 0, -2);*/ - terminal_inferior (); - wait_for_inferior (); - normal_stop (); -} -#endif /* ATTACH_DETACH */ - -/* Wait for control to return from inferior to debugger. - If inferior gets a signal, we may decide to start it up again - instead of returning. That is why there is a loop in this function. - When this function actually returns it means the inferior - should be left stopped and GDB should read more commands. */ - -static void -wait_for_inferior () -{ - register int pid; - WAITTYPE w; - CORE_ADDR pc; - int tem; - int another_trap; - int random_signal; - CORE_ADDR stop_sp, prev_sp; - CORE_ADDR prev_func_start, stop_func_start; - char *prev_func_name, *stop_func_name; - CORE_ADDR prologue_pc; - int stop_step_resume_break; - CORE_ADDR step_resume_break_sp; - int newmisc; - int newfun_pc; - struct symtab_and_line sal; - int prev_pc; - extern CORE_ADDR text_end; - int remove_breakpoints_on_following_step = 0; - - 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); - - while (1) - { - /* Clean up saved state that will become invalid. */ - pc_changed = 0; - flush_cached_frames (); - - if (remote_debugging) - remote_wait (&w); - else - { - pid = wait (&w); - if (pid != inferior_pid) - continue; - } - - /* See if the process still exists; clean up if it doesn't. */ - if (WIFEXITED (w)) - { - terminal_ours_for_output (); - if (WRETCODE (w)) - printf ("\nProgram exited with code 0%o.\n", WRETCODE (w)); - else - printf ("\nProgram exited normally.\n"); - fflush (stdout); - inferior_died (); -#ifdef NO_SINGLE_STEP - one_stepped = 0; -#endif - stop_print_frame = 0; - break; - } - else if (!WIFSTOPPED (w)) - { - kill_inferior (); - stop_print_frame = 0; - stop_signal = WTERMSIG (w); - terminal_ours_for_output (); - printf ("\nProgram terminated with signal %d, %s\n", - stop_signal, - stop_signal < NSIG - ? sys_siglist[stop_signal] - : "(undocumented)"); - printf ("The inferior process no longer exists.\n"); - fflush (stdout); -#ifdef NO_SINGLE_STEP - one_stepped = 0; -#endif - break; - } - -#ifdef NO_SINGLE_STEP - if (one_stepped) - single_step (0); /* This actually cleans up the ss */ -#endif /* NO_SINGLE_STEP */ - - fetch_inferior_registers (); - stop_pc = read_pc (); - set_current_frame ( create_new_frame (read_register (FP_REGNUM), - read_pc ())); - - stop_frame_address = FRAME_FP (get_current_frame ()); - stop_sp = read_register (SP_REGNUM); - stop_func_start = 0; - stop_func_name = 0; - /* Don't care about return value; stop_func_start and stop_func_name - will both be 0 if it doesn't work. */ - (void) find_pc_partial_function (stop_pc, &stop_func_name, - &stop_func_start); - stop_func_start += FUNCTION_START_OFFSET; - another_trap = 0; - stop_breakpoint = 0; - stop_step = 0; - stop_stack_dummy = 0; - stop_print_frame = 1; - stop_step_resume_break = 0; - random_signal = 0; - stopped_by_random_signal = 0; - breakpoints_failed = 0; - - /* Look at the cause of the stop, and decide what to do. - The alternatives are: - 1) break; to really stop and return to the debugger, - 2) drop through to start up again - (set another_trap to 1 to single step once) - 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 - or SIGEMT, depending on the operating system version. - Here we detect when a SIGILL or SIGEMT is really a breakpoint - and change it to SIGTRAP. */ - - if (stop_signal == SIGTRAP - || (breakpoints_inserted && - (stop_signal == SIGILL - || stop_signal == SIGEMT)) - || stop_after_attach) - { - if (stop_signal == SIGTRAP && stop_after_trap) - { - stop_print_frame = 0; - break; - } - if (stop_after_attach) - break; - /* Don't even think about breakpoints - if still running the shell that will exec the program - or if just proceeded over a breakpoint. */ - if (stop_signal == SIGTRAP && trap_expected) - stop_breakpoint = 0; - else - { - /* See if there is a breakpoint at the current PC. */ -#if DECR_PC_AFTER_BREAK - /* Notice the case of stepping through a jump - that leads just after a breakpoint. - Don't confuse that with hitting the breakpoint. - What we check for is that 1) stepping is going on - and 2) the pc before the last insn does not match - the address of the breakpoint before the current pc. */ - if (!(prev_pc != stop_pc - DECR_PC_AFTER_BREAK - && step_range_end && !step_resume_break_address)) -#endif /* DECR_PC_AFTER_BREAK not zero */ - { - /* See if we stopped at the special breakpoint for - stepping over a subroutine call. */ - if (stop_pc - DECR_PC_AFTER_BREAK - == step_resume_break_address) - { - stop_step_resume_break = 1; - if (DECR_PC_AFTER_BREAK) - { - stop_pc -= DECR_PC_AFTER_BREAK; - write_register (PC_REGNUM, stop_pc); - pc_changed = 0; - } - } - else - { - stop_breakpoint = - breakpoint_stop_status (stop_pc, stop_frame_address); - /* Following in case break condition called a - function. */ - stop_print_frame = 1; - if (stop_breakpoint && DECR_PC_AFTER_BREAK) - { - stop_pc -= DECR_PC_AFTER_BREAK; - write_register (PC_REGNUM, stop_pc); -#ifdef NPC_REGNUM - write_register (NPC_REGNUM, stop_pc + 4); -#endif - pc_changed = 0; - } - } - } - } - - if (stop_signal == SIGTRAP) - random_signal - = !(stop_breakpoint || trap_expected - || stop_step_resume_break -#ifndef CANNOT_EXECUTE_STACK - || (stop_sp INNER_THAN stop_pc - && stop_pc INNER_THAN stop_frame_address) -#else - || stop_pc == text_end - 2 -#endif - || (step_range_end && !step_resume_break_address)); - else - { - random_signal - = !(stop_breakpoint - || stop_step_resume_break -#ifdef sony_news - || (stop_sp INNER_THAN stop_pc - && stop_pc INNER_THAN stop_frame_address) -#endif - - ); - if (!random_signal) - stop_signal = SIGTRAP; - } - } - else - random_signal = 1; - - /* For the program's own signals, act according to - the signal handling tables. */ - - if (random_signal - && !(running_in_shell && stop_signal == SIGSEGV)) - { - /* Signal not for debugging purposes. */ - int printed = 0; - - stopped_by_random_signal = 1; - - if (stop_signal >= NSIG - || signal_print[stop_signal]) - { - printed = 1; - terminal_ours_for_output (); - printf ("\nProgram received signal %d, %s\n", - stop_signal, - stop_signal < NSIG - ? sys_siglist[stop_signal] - : "(undocumented)"); - fflush (stdout); - } - if (stop_signal >= NSIG - || signal_stop[stop_signal]) - break; - /* If not going to stop, give terminal back - if we took it away. */ - else if (printed) - terminal_inferior (); - } - - /* Handle cases caused by hitting a breakpoint. */ - - if (!random_signal - && (stop_breakpoint || stop_step_resume_break)) - { - /* Does a breakpoint want us to stop? */ - if (stop_breakpoint && stop_breakpoint != -1 - && stop_breakpoint != -0x1000001) - { - /* 0x1000000 is set in stop_breakpoint as returned by - breakpoint_stop_status to indicate a silent - breakpoint. */ - if ((stop_breakpoint > 0 ? stop_breakpoint : - -stop_breakpoint) - & 0x1000000) - { - stop_print_frame = 0; - if (stop_breakpoint > 0) - stop_breakpoint -= 0x1000000; - else - stop_breakpoint += 0x1000000; - } - 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; - } - /* 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; - } - - /* 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, - just stop silently. */ -#ifndef CANNOT_EXECUTE_STACK - if (stop_sp INNER_THAN stop_pc - && stop_pc INNER_THAN stop_frame_address) -#else - if (stop_pc == text_end - 2) -#endif - { - stop_print_frame = 0; - stop_stack_dummy = 1; -#ifdef HP_OS_BUG - trap_expected_after_continue = 1; -#endif - break; - } - - if (step_resume_break_address) - /* Having a step-resume breakpoint overrides anything - else having to do with stepping commands until - that breakpoint is reached. */ - ; - /* If stepping through a line, keep going if still within it. */ - else if (!random_signal - && step_range_end - && stop_pc >= step_range_start - && stop_pc < step_range_end - /* The step range might include the start of the - function, so if we are at the start of the - step range and either the stack or frame pointers - just changed, we've stepped outside */ - && !(stop_pc == step_range_start - && stop_frame_address - && (stop_sp INNER_THAN prev_sp - || stop_frame_address != step_frame_address))) - { - /* 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; - } - } - - /* We stepped out of the stepping range. See if that was due - to a subroutine call that we should proceed to the end of. */ - else if (!random_signal && step_range_end) - { - if (stop_func_start) - { - prologue_pc = stop_func_start; - SKIP_PROLOGUE (prologue_pc); - } - - /* Did we just take a signal? */ - if (IN_SIGTRAMP (stop_pc, stop_func_name) - && !IN_SIGTRAMP (prev_pc, prev_func_name)) - { - /* This code is needed at least in the following case: - The user types "next" and then a signal arrives (before - the "next" is done). */ - /* We've just taken a signal; go until we are back to - the point where we took it and one more. */ - step_resume_break_address = prev_pc; - step_resume_break_duplicate = - breakpoint_here_p (step_resume_break_address); - step_resume_break_sp = stop_sp; - if (breakpoints_inserted) - insert_step_breakpoint (); - /* Make sure that the stepping range gets us past - that instruction. */ - if (step_range_end == 1) - step_range_end = (step_range_start = prev_pc) + 1; - remove_breakpoints_on_following_step = 1; - } - - /* ==> See comments at top of file on this algorithm. <==*/ - - else 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)) - { - /* A subroutine call has happened. */ - /* Set a special breakpoint after the return */ - step_resume_break_address = - SAVED_PC_AFTER_CALL (get_current_frame ()); - step_resume_break_duplicate - = breakpoint_here_p (step_resume_break_address); - step_resume_break_sp = stop_sp; - if (breakpoints_inserted) - insert_step_breakpoint (); - } - /* 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. */ -#ifdef PROLOGUE_FIRSTLINE_OVERLAP - /* 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; -#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_sp = stop_sp; - - 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 subroutince call; stop now. */ - else - { - stop_step = 1; - break; - } - } - - /* 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 - BREAK is defined, the - original pc would not have - been at the start of a - function. */ - prev_func_name = stop_func_name; - prev_sp = stop_sp; - - /* If we did not do break;, it means we should keep - running the inferior and not return to debugger. */ - - /* If trap_expected is 2, it means continue once more - and insert breakpoints at the next trap. - If trap_expected is 1 and the signal was SIGSEGV, it means - the shell is doing some memory allocation--just resume it - with SIGSEGV. - Otherwise insert breakpoints now, and possibly single step. */ - - if (trap_expected > 1) - { - trap_expected--; - running_in_shell = 1; - resume (0, 0); - } - else if (running_in_shell && stop_signal == SIGSEGV) - { - resume (0, SIGSEGV); - } - else if (trap_expected && stop_signal != SIGTRAP) - { - /* We took a signal which we are supposed to pass through to - the inferior and we haven't yet gotten our trap. Simply - continue. */ - resume ((step_range_end && !step_resume_break_address) - || trap_expected, - stop_signal); - } - else - { - /* Here, we are not awaiting another exec to get - the program we really want to debug. - Insert breakpoints now, unless we are trying - to one-proceed past a breakpoint. */ - running_in_shell = 0; - /* If we've just finished a special step resume and we don't - want to hit a breakpoint, pull em out. */ - if (!step_resume_break_address && - remove_breakpoints_on_following_step) - { - remove_breakpoints_on_following_step = 0; - remove_breakpoints (); - breakpoints_inserted = 0; - } - else if (!breakpoints_inserted && !another_trap) - { - insert_step_breakpoint (); - breakpoints_failed = insert_breakpoints (); - if (breakpoints_failed) - break; - breakpoints_inserted = 1; - } - - trap_expected = another_trap; - - if (stop_signal == SIGTRAP) - stop_signal = 0; - - resume ((step_range_end && !step_resume_break_address) - || trap_expected, - stop_signal); - } - } -} - -/* Here to return control to GDB when the inferior stops for real. - Print appropriate messages, remove breakpoints, give terminal our modes. - - RUNNING_IN_SHELL nonzero means the shell got a signal before - exec'ing the program we wanted to run. - STOP_PRINT_FRAME nonzero means print the executing frame - (pc, function, args, file, line number and line text). - BREAKPOINTS_FAILED nonzero means stop was due to error - attempting to insert breakpoints. */ - -static void -normal_stop () -{ - /* 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 (inferior_pid) - (get_current_frame ())->pc = read_pc (); - - if (breakpoints_failed) - { - terminal_ours_for_output (); - print_sys_errmsg ("ptrace", breakpoints_failed); - printf ("Stopped; cannot insert breakpoints.\n\ -The same program may be running in another process.\n"); - } - - if (inferior_pid) - remove_step_breakpoint (); - - if (inferior_pid && breakpoints_inserted) - if (remove_breakpoints ()) - { - terminal_ours_for_output (); - printf ("Cannot remove breakpoints because program is no longer writable.\n\ -It must be running in another process.\n\ -Further execution is probably impossible.\n"); - } - - breakpoints_inserted = 0; - - /* Delete the breakpoint we stopped at, if it wants to be deleted. - Delete any breakpoint that is to be deleted at the next stop. */ - - breakpoint_auto_delete (stop_breakpoint); - - /* If an auto-display called a function and that got a signal, - delete that auto-display to avoid an infinite recursion. */ - - if (stopped_by_random_signal) - disable_current_display (); - - if (step_multi && stop_step) - return; - - terminal_ours (); - - if (running_in_shell) - { - if (stop_signal == SIGSEGV) - { - char *exec_file = (char *) get_exec_file (1); - - if (access (exec_file, X_OK) != 0) - printf ("The file \"%s\" is not executable.\n", exec_file); - else - /* I don't think we should ever get here. - wait_for_inferior now ignores SIGSEGV's which happen in - the shell (since the Bourne shell (/bin/sh) has some - rather, er, uh, *unorthodox* memory management - involving catching SIGSEGV). */ - printf ("\ -You have just encountered a bug in \"sh\". GDB starts your program\n\ -by running \"sh\" with a command to exec your program.\n\ -This is so that \"sh\" will process wildcards and I/O redirection.\n\ -This time, \"sh\" crashed.\n\ -\n\ -One known bug in \"sh\" bites when the environment takes up a lot of space.\n\ -Try \"info env\" to see the environment; then use \"delete env\" to kill\n\ -some variables whose values are large; then do \"run\" again.\n\ -\n\ -If that works, you might want to put those \"delete env\" commands\n\ -into a \".gdbinit\" file in this directory so they will happen every time.\n"); - } - /* Don't confuse user with his program's symbols on sh's data. */ - stop_print_frame = 0; - } - - if (inferior_pid == 0) - return; - - /* Select innermost stack frame except on return from a stack dummy routine, - or if the program has exited. */ - if (!stop_stack_dummy) - { - select_frame (get_current_frame (), 0); - - if (stop_print_frame) - { - if (stop_breakpoint > 0) - printf ("\nBpt %d, ", stop_breakpoint); - print_sel_frame (stop_step - && step_frame_address == stop_frame_address - && step_start_function == find_pc_function (stop_pc)); - /* Display the auto-display expressions. */ - do_displays (); - } - } - - /* Save the function value return registers - We might be about to restore their previous contents. */ - read_register_bytes (0, stop_registers, REGISTER_BYTES); - - if (stop_stack_dummy) - { - /* Pop the empty frame that contains the stack dummy. - POP_FRAME ends with a setting of the current frame, so we - can use that next. */ - POP_FRAME; - select_frame (get_current_frame (), 0); - } -} - -static void -insert_step_breakpoint () -{ - if (step_resume_break_address && !step_resume_break_duplicate) - { - read_memory (step_resume_break_address, - step_resume_break_shadow, sizeof break_insn); - write_memory (step_resume_break_address, - break_insn, sizeof break_insn); - } -} - -static void -remove_step_breakpoint () -{ - if (step_resume_break_address && !step_resume_break_duplicate) - write_memory (step_resume_break_address, step_resume_break_shadow, - sizeof break_insn); -} - -/* Specify how various signals in the inferior should be handled. */ - -static void -handle_command (args, from_tty) - char *args; - int from_tty; -{ - register char *p = args; - int signum = 0; - register int digits, wordlen; - - if (!args) - error_no_arg ("signal to handle"); - - while (*p) - { - /* Find the end of the next word in the args. */ - for (wordlen = 0; p[wordlen] && p[wordlen] != ' ' && p[wordlen] != '\t'; - wordlen++); - for (digits = 0; p[digits] >= '0' && p[digits] <= '9'; digits++); - - /* If it is all digits, it is signal number to operate on. */ - if (digits == wordlen) - { - signum = atoi (p); - if (signum <= 0 || signum >= NSIG) - { - p[wordlen] = '\0'; - error ("Invalid signal %s given as argument to \"handle\".", p); - } - if (signum == SIGTRAP || signum == SIGINT) - { - if (!query ("Signal %d is used by the debugger.\nAre you sure you want to change it? ", signum)) - error ("Not confirmed."); - } - } - else if (signum == 0) - error ("First argument is not a signal number."); - - /* Else, if already got a signal number, look for flag words - saying what to do for it. */ - else if (!strncmp (p, "stop", wordlen)) - { - signal_stop[signum] = 1; - signal_print[signum] = 1; - } - else if (wordlen >= 2 && !strncmp (p, "print", wordlen)) - signal_print[signum] = 1; - else if (wordlen >= 2 && !strncmp (p, "pass", wordlen)) - signal_program[signum] = 1; - else if (!strncmp (p, "ignore", wordlen)) - signal_program[signum] = 0; - else if (wordlen >= 3 && !strncmp (p, "nostop", wordlen)) - signal_stop[signum] = 0; - else if (wordlen >= 4 && !strncmp (p, "noprint", wordlen)) - { - signal_print[signum] = 0; - signal_stop[signum] = 0; - } - else if (wordlen >= 4 && !strncmp (p, "nopass", wordlen)) - signal_program[signum] = 0; - else if (wordlen >= 3 && !strncmp (p, "noignore", wordlen)) - signal_program[signum] = 1; - /* Not a number and not a recognized flag word => complain. */ - else - { - p[wordlen] = 0; - error ("Unrecognized flag word: \"%s\".", p); - } - - /* Find start of next word. */ - p += wordlen; - while (*p == ' ' || *p == '\t') p++; - } - - if (from_tty) - { - /* Show the results. */ - printf ("Number\tStop\tPrint\tPass to program\tDescription\n"); - printf ("%d\t", signum); - printf ("%s\t", signal_stop[signum] ? "Yes" : "No"); - printf ("%s\t", signal_print[signum] ? "Yes" : "No"); - printf ("%s\t\t", signal_program[signum] ? "Yes" : "No"); - printf ("%s\n", sys_siglist[signum]); - } -} - -/* Print current contents of the tables set by the handle command. */ - -static void -signals_info (signum_exp) - char *signum_exp; -{ - register int i; - printf_filtered ("Number\tStop\tPrint\tPass to program\tDescription\n"); - - if (signum_exp) - { - i = parse_and_eval_address (signum_exp); - if (i >= NSIG || i < 0) - error ("Signal number out of bounds."); - printf_filtered ("%d\t", i); - printf_filtered ("%s\t", signal_stop[i] ? "Yes" : "No"); - printf_filtered ("%s\t", signal_print[i] ? "Yes" : "No"); - printf_filtered ("%s\t\t", signal_program[i] ? "Yes" : "No"); - printf_filtered ("%s\n", sys_siglist[i]); - return; - } - - printf_filtered ("\n"); - for (i = 0; i < NSIG; i++) - { - QUIT; - - printf_filtered ("%d\t", i); - printf_filtered ("%s\t", signal_stop[i] ? "Yes" : "No"); - printf_filtered ("%s\t", signal_print[i] ? "Yes" : "No"); - printf_filtered ("%s\t\t", signal_program[i] ? "Yes" : "No"); - printf_filtered ("%s\n", sys_siglist[i]); - } - - printf_filtered ("\nUse the \"handle\" command to change these tables.\n"); -} - -/* Save all of the information associated with the inferior<==>gdb - connection. INF_STATUS is a pointer to a "struct inferior_status" - (defined in inferior.h). */ - -struct command_line *get_breakpoint_commands (); - -void -save_inferior_status (inf_status, restore_stack_info) - struct inferior_status *inf_status; - int restore_stack_info; -{ - inf_status->pc_changed = pc_changed; - inf_status->stop_signal = stop_signal; - inf_status->stop_pc = stop_pc; - inf_status->stop_frame_address = stop_frame_address; - inf_status->stop_breakpoint = stop_breakpoint; - inf_status->stop_step = stop_step; - inf_status->stop_stack_dummy = stop_stack_dummy; - inf_status->stopped_by_random_signal = stopped_by_random_signal; - inf_status->trap_expected = trap_expected; - inf_status->step_range_start = step_range_start; - inf_status->step_range_end = step_range_end; - inf_status->step_frame_address = step_frame_address; - inf_status->step_over_calls = step_over_calls; - inf_status->step_resume_break_address = step_resume_break_address; - inf_status->stop_after_trap = stop_after_trap; - inf_status->stop_after_attach = stop_after_attach; - inf_status->breakpoint_commands = get_breakpoint_commands (); - inf_status->restore_stack_info = restore_stack_info; - - bcopy (stop_registers, inf_status->stop_registers, REGISTER_BYTES); - - record_selected_frame (&(inf_status->selected_frame_address), - &(inf_status->selected_level)); - return; -} - -void -restore_inferior_status (inf_status) - struct inferior_status *inf_status; -{ - FRAME fid; - int level = inf_status->selected_level; - - pc_changed = inf_status->pc_changed; - stop_signal = inf_status->stop_signal; - stop_pc = inf_status->stop_pc; - stop_frame_address = inf_status->stop_frame_address; - stop_breakpoint = inf_status->stop_breakpoint; - stop_step = inf_status->stop_step; - stop_stack_dummy = inf_status->stop_stack_dummy; - stopped_by_random_signal = inf_status->stopped_by_random_signal; - trap_expected = inf_status->trap_expected; - step_range_start = inf_status->step_range_start; - step_range_end = inf_status->step_range_end; - step_frame_address = inf_status->step_frame_address; - step_over_calls = inf_status->step_over_calls; - step_resume_break_address = inf_status->step_resume_break_address; - stop_after_trap = inf_status->stop_after_trap; - stop_after_attach = inf_status->stop_after_attach; - set_breakpoint_commands (inf_status->breakpoint_commands); - - bcopy (inf_status->stop_registers, stop_registers, REGISTER_BYTES); - - /* The inferior can be gone if the user types "print exit(0)" - (and perhaps other times). */ - if (have_inferior_p() && inf_status->restore_stack_info) - { - fid = find_relative_frame (get_current_frame (), - &level); - - if (fid == 0 || - FRAME_FP (fid) != inf_status->selected_frame_address || - level != 0) - { - /* 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 - which case it just adds insult to injury (one confusing - error message after another. Besides which, does the - user really care if we can't restore the previously - selected frame? */ - fprintf (stderr, "Unable to restore previously selected frame.\n"); - select_frame (get_current_frame (), 0); - return; - } - - select_frame (fid, inf_status->selected_level); - } - return; -} - - -void -_initialize_infrun () -{ - register int i; - - add_info ("signals", signals_info, - "What debugger does when program gets various signals.\n\ -Specify a signal number as argument to print info on that signal only."); - - add_com ("handle", class_run, handle_command, - "Specify how to handle a signal.\n\ -Args are signal number followed by flags.\n\ -Flags allowed are \"stop\", \"print\", \"pass\",\n\ - \"nostop\", \"noprint\" or \"nopass\".\n\ -Print means print a message if this signal happens.\n\ -Stop means reenter debugger if this signal happens (implies print).\n\ -Pass means let program see this signal; otherwise program doesn't know.\n\ -Pass and Stop may be combined."); - - for (i = 0; i < NSIG; i++) - { - signal_stop[i] = 1; - signal_print[i] = 1; - signal_program[i] = 1; - } - - /* Signals caused by debugger's own actions - should not be given to the program afterwards. */ - signal_program[SIGTRAP] = 0; - signal_program[SIGINT] = 0; - - /* Signals that are not errors should not normally enter the debugger. */ -#ifdef SIGALRM - signal_stop[SIGALRM] = 0; - signal_print[SIGALRM] = 0; -#endif /* SIGALRM */ -#ifdef SIGVTALRM - signal_stop[SIGVTALRM] = 0; - signal_print[SIGVTALRM] = 0; -#endif /* SIGVTALRM */ -#ifdef SIGPROF - signal_stop[SIGPROF] = 0; - signal_print[SIGPROF] = 0; -#endif /* SIGPROF */ -#ifdef SIGCHLD - signal_stop[SIGCHLD] = 0; - signal_print[SIGCHLD] = 0; -#endif /* SIGCHLD */ -#ifdef SIGCLD - signal_stop[SIGCLD] = 0; - signal_print[SIGCLD] = 0; -#endif /* SIGCLD */ -#ifdef SIGIO - signal_stop[SIGIO] = 0; - signal_print[SIGIO] = 0; -#endif /* SIGIO */ -#ifdef SIGURG - signal_stop[SIGURG] = 0; - signal_print[SIGURG] = 0; -#endif /* SIGURG */ -} - |