/* Target-struct-independent code to start (run) and stop an inferior process.
- Copyright 1986, 1987, 1988, 1989, 1991, 1992, 1993, 1994
+ Copyright 1986, 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996
Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "gdb_string.h"
#define SKIP_TRAMPOLINE_CODE(pc) 0
#endif
+/* Dynamic function trampolines are similar to solib trampolines in that they
+ are between the caller and the callee. The difference is that when you
+ enter a dynamic trampoline, you can't determine the callee's address. Some
+ (usually complex) code needs to run in the dynamic trampoline to figure out
+ the callee's address. This macro is usually called twice. First, when we
+ enter the trampoline (looks like a normal function call at that point). It
+ should return the PC of a point within the trampoline where the callee's
+ address is known. Second, when we hit the breakpoint, this routine returns
+ the callee's address. At that point, things proceed as per a step resume
+ breakpoint. */
+
+#ifndef DYNAMIC_TRAMPOLINE_NEXTPC
+#define DYNAMIC_TRAMPOLINE_NEXTPC(pc) 0
+#endif
+
/* For SVR4 shared libraries, each call goes through a small piece of
trampoline code in the ".plt" section. IN_SOLIB_CALL_TRAMPOLINE evaluates
to nonzero if we are current stopped in one of these. */
static int trap_expected;
+/* Nonzero if we want to give control to the user when we're notified
+ of shared library events by the dynamic linker. */
+static int stop_on_solib_events;
+
#ifdef HP_OS_BUG
/* Nonzero if the next time we try to continue the inferior, it will
step one instruction and generate a spurious trace trap.
another_trap = 1;
break;
+#ifdef SOLIB_ADD
+ case BPSTAT_WHAT_CHECK_SHLIBS:
+ {
+ extern int auto_solib_add;
+
+ /* Check for any newly added shared libraries if we're
+ supposed to be adding them automatically. */
+ if (auto_solib_add)
+ {
+ /* Remove breakpoints, SOLIB_ADD might adjust breakpoint
+ addresses via breakpoint_re_set. */
+ if (breakpoints_inserted)
+ remove_breakpoints ();
+ breakpoints_inserted = 0;
+
+ /* Switch terminal for any messages produced by
+ breakpoint_re_set. */
+ target_terminal_ours_for_output ();
+ SOLIB_ADD (NULL, 0, NULL);
+ target_terminal_inferior ();
+ }
+
+ /* If requested, stop when the dynamic linker notifies
+ gdb of events. This allows the user to get control
+ and place breakpoints in initializer routines for
+ dynamically loaded objects (among other things). */
+ if (stop_on_solib_events)
+ {
+ stop_print_frame = 0;
+ goto stop_stepping;
+ }
+ else
+ {
+ /* We want to step over this breakpoint, then keep going. */
+ another_trap = 1;
+ remove_breakpoints_on_following_step = 1;
+ break;
+ }
+ }
+#endif
+
case BPSTAT_WHAT_LAST:
/* Not a real code, but listed here to shut up gcc -Wall. */
/* If stepping through a line, keep going if still within it. */
if (stop_pc >= step_range_start
&& stop_pc < step_range_end
+#if 0
+/* I haven't a clue what might trigger this clause, and it seems wrong anyway,
+ so I've disabled it until someone complains. -Stu 10/24/95 */
+
/* 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
&& !(stop_pc == step_range_start
&& FRAME_FP (get_current_frame ())
&& (read_sp () INNER_THAN step_sp
- || FRAME_FP (get_current_frame ()) != step_frame_address)))
+ || FRAME_FP (get_current_frame ()) != step_frame_address))
+#endif
+)
{
/* We might be doing a BPSTAT_WHAT_SINGLE and getting a signal.
So definately need to check for sigtramp here. */
goto keep_going;
}
-#if 1
+#if 0
+ /* I disabled this test because it was too complicated and slow. The
+ SKIP_PROLOGUE was especially slow, because it caused unnecessary
+ prologue examination on various architectures. The code in the #else
+ clause has been tested on the Sparc, Mips, PA, and Power
+ architectures, so it's pretty likely to be correct. -Stu 10/24/95 */
+
/* See if we left the step range due to a subroutine call that
we should proceed to the end of. */
handling_longjmp stuff is working. */
))
#else
-/* This is experimental code which greatly simplifies the subroutine call
- test. I've actually tested on the Alpha, and it works great. -Stu */
-
- if (in_prologue (stop_pc, NULL)
- || (prev_func_start != 0
- && stop_func_start == 0))
+ /* This test is a much more streamlined, (but hopefully correct)
+ replacement for the code above. It's been tested on the Sparc,
+ Mips, PA, and Power architectures with good results. */
+
+ if (stop_pc == stop_func_start /* Quick test */
+ || in_prologue (stop_pc, stop_func_start)
+ || IN_SOLIB_CALL_TRAMPOLINE (stop_pc, stop_func_name)
+ || stop_func_start == 0)
#endif
+
{
/* It's a subroutine call. */
tmp = SKIP_TRAMPOLINE_CODE (stop_pc);
if (tmp != 0)
stop_func_start = tmp;
+ else
+ {
+ tmp = DYNAMIC_TRAMPOLINE_NEXTPC (stop_pc);
+ if (tmp)
+ {
+ struct symtab_and_line xxx;
+
+ xxx.pc = tmp;
+ xxx.symtab = NULL;
+ xxx.line = 0;
+ step_resume_breakpoint =
+ set_momentary_breakpoint (xxx, NULL, bp_step_resume);
+ insert_breakpoints ();
+ goto keep_going;
+ }
+ }
/* If we have line number information for the function we
are thinking of stepping into, step into it.
target_terminal_ours ();
+ if (stop_bpstat
+ && stop_bpstat->breakpoint_at
+ && stop_bpstat->breakpoint_at->type == bp_shlib_event)
+ printf_filtered ("Stopped due to shared library event\n");
+
/* Look up the hook_stop and run it if it exists. */
if (stop_command->hook)
signal_print[TARGET_SIGNAL_POLL] = 0;
signal_stop[TARGET_SIGNAL_URG] = 0;
signal_print[TARGET_SIGNAL_URG] = 0;
+
+#ifdef SOLIB_ADD
+ add_show_from_set
+ (add_set_cmd ("stop-on-solib-events", class_support, var_zinteger,
+ (char *) &stop_on_solib_events,
+ "Set stopping for shared library events.\n\
+If nonzero, gdb will give control to the user when the dynamic linker\n\
+notifies gdb of shared library events. The most common event of interest\n\
+to the user would be loading/unloading of a new library.\n",
+ &setlist),
+ &showlist);
+#endif
}
projects / deliverable / binutils-gdb.git / blobdiff