/* Code dealing with dummy stack frames, for GDB, the GNU debugger.
- Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
- 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free
- Software Foundation, Inc.
+ Copyright (C) 1986-2017 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "regcache.h"
#include "frame.h"
#include "inferior.h"
-#include "gdb_assert.h"
#include "frame-unwind.h"
#include "command.h"
#include "gdbcmd.h"
-#include "gdb_string.h"
+#include "observer.h"
+#include "gdbthread.h"
+#include "infcall.h"
+
+struct dummy_frame_id
+{
+ /* This frame's ID. Must match the value returned by
+ gdbarch_dummy_id. */
+ struct frame_id id;
+
+ /* The thread this dummy_frame relates to. */
+ ptid_t ptid;
+};
+
+/* Return whether dummy_frame_id *ID1 and *ID2 are equal. */
+
+static int
+dummy_frame_id_eq (struct dummy_frame_id *id1,
+ struct dummy_frame_id *id2)
+{
+ return frame_id_eq (id1->id, id2->id) && ptid_equal (id1->ptid, id2->ptid);
+}
+
+/* List of dummy_frame destructors. */
+
+struct dummy_frame_dtor_list
+{
+ /* Next element in the list or NULL if this is the last element. */
+ struct dummy_frame_dtor_list *next;
+
+ /* If non-NULL, a destructor that is run when this dummy frame is freed. */
+ dummy_frame_dtor_ftype *dtor;
+
+ /* Arbitrary data that is passed to DTOR. */
+ void *dtor_data;
+};
/* Dummy frame. This saves the processor state just prior to setting
up the inferior function call. Older targets save the registers
struct dummy_frame
{
struct dummy_frame *next;
- /* This frame's ID. Must match the value returned by
- gdbarch_unwind_dummy_id. */
- struct frame_id id;
- /* The caller's regcache. */
- struct regcache *regcache;
+
+ /* An id represents a dummy frame. */
+ struct dummy_frame_id id;
+
+ /* The caller's state prior to the call. */
+ struct infcall_suspend_state *caller_state;
+
+ /* First element of destructors list or NULL if there are no
+ destructors registered for this dummy_frame. */
+ struct dummy_frame_dtor_list *dtor_list;
};
static struct dummy_frame *dummy_frame_stack = NULL;
-/* Function: deprecated_pc_in_call_dummy (pc)
+/* Push the caller's state, along with the dummy frame info, onto the
+ dummy-frame stack. */
- Return non-zero if the PC falls in a dummy frame created by gdb for
- an inferior call. The code below which allows DECR_PC_AFTER_BREAK
- is for infrun.c, which may give the function a PC without that
- subtracted out.
+void
+dummy_frame_push (struct infcall_suspend_state *caller_state,
+ const struct frame_id *dummy_id, ptid_t ptid)
+{
+ struct dummy_frame *dummy_frame;
- FIXME: cagney/2002-11-23: This is silly. Surely "infrun.c" can
- figure out what the real PC (as in the resume address) is BEFORE
- calling this function.
+ dummy_frame = XCNEW (struct dummy_frame);
+ dummy_frame->caller_state = caller_state;
+ dummy_frame->id.id = (*dummy_id);
+ dummy_frame->id.ptid = ptid;
+ dummy_frame->next = dummy_frame_stack;
+ dummy_frame_stack = dummy_frame;
+}
- NOTE: cagney/2004-08-02: I'm pretty sure that, with the introduction of
- infrun.c:adjust_pc_after_break (thanks), this function is now
- always called with a correctly adjusted PC!
+/* Remove *DUMMY_PTR from the dummy frame stack. */
- NOTE: cagney/2004-08-02: Code should not need to call this. */
+static void
+remove_dummy_frame (struct dummy_frame **dummy_ptr)
+{
+ struct dummy_frame *dummy = *dummy_ptr;
-int
-deprecated_pc_in_call_dummy (CORE_ADDR pc)
+ while (dummy->dtor_list != NULL)
+ {
+ struct dummy_frame_dtor_list *list = dummy->dtor_list;
+
+ dummy->dtor_list = list->next;
+ list->dtor (list->dtor_data, 0);
+ xfree (list);
+ }
+
+ *dummy_ptr = dummy->next;
+ discard_infcall_suspend_state (dummy->caller_state);
+ xfree (dummy);
+}
+
+/* Delete any breakpoint B which is a momentary breakpoint for return from
+ inferior call matching DUMMY_VOIDP. */
+
+static int
+pop_dummy_frame_bpt (struct breakpoint *b, void *dummy_voidp)
{
- struct dummy_frame *dummyframe;
- for (dummyframe = dummy_frame_stack;
- dummyframe != NULL;
- dummyframe = dummyframe->next)
+ struct dummy_frame *dummy = (struct dummy_frame *) dummy_voidp;
+
+ if (b->thread == ptid_to_global_thread_id (dummy->id.ptid)
+ && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id.id))
{
- if ((pc >= dummyframe->id.code_addr)
- && (pc <= dummyframe->id.code_addr + DECR_PC_AFTER_BREAK))
- return 1;
+ while (b->related_breakpoint != b)
+ delete_breakpoint (b->related_breakpoint);
+
+ delete_breakpoint (b);
+
+ /* Stop the traversal. */
+ return 1;
}
+
+ /* Continue the traversal. */
return 0;
}
-/* Push the caller's state, along with the dummy frame info, onto a
- dummy-frame stack. */
+/* Pop *DUMMY_PTR, restoring program state to that before the
+ frame was created. */
+
+static void
+pop_dummy_frame (struct dummy_frame **dummy_ptr)
+{
+ struct dummy_frame *dummy = *dummy_ptr;
+
+ gdb_assert (ptid_equal (dummy->id.ptid, inferior_ptid));
+
+ while (dummy->dtor_list != NULL)
+ {
+ struct dummy_frame_dtor_list *list = dummy->dtor_list;
+
+ dummy->dtor_list = list->next;
+ list->dtor (list->dtor_data, 1);
+ xfree (list);
+ }
+
+ restore_infcall_suspend_state (dummy->caller_state);
+
+ iterate_over_breakpoints (pop_dummy_frame_bpt, dummy);
+
+ /* restore_infcall_control_state frees inf_state,
+ all that remains is to pop *dummy_ptr. */
+ *dummy_ptr = dummy->next;
+ xfree (dummy);
+
+ /* We've made right mess of GDB's local state, just discard
+ everything. */
+ reinit_frame_cache ();
+}
+
+/* Look up DUMMY_ID.
+ Return NULL if not found. */
+
+static struct dummy_frame **
+lookup_dummy_frame (struct dummy_frame_id *dummy_id)
+{
+ struct dummy_frame **dp;
+
+ for (dp = &dummy_frame_stack; *dp != NULL; dp = &(*dp)->next)
+ {
+ if (dummy_frame_id_eq (&(*dp)->id, dummy_id))
+ return dp;
+ }
+
+ return NULL;
+}
+
+/* Find the dummy frame by DUMMY_ID and PTID, and pop it, restoring
+ program state to that before the frame was created.
+ On return reinit_frame_cache has been called.
+ If the frame isn't found, flag an internal error. */
void
-dummy_frame_push (struct regcache *caller_regcache,
- const struct frame_id *dummy_id)
+dummy_frame_pop (struct frame_id dummy_id, ptid_t ptid)
{
- struct dummy_frame *dummy_frame;
+ struct dummy_frame **dp;
+ struct dummy_frame_id id = { dummy_id, ptid };
- /* Check to see if there are stale dummy frames, perhaps left over
- from when a longjump took us out of a function that was called by
- the debugger. */
- dummy_frame = dummy_frame_stack;
- while (dummy_frame)
- /* FIXME: cagney/2004-08-02: Should just test IDs. */
- if (frame_id_inner (dummy_frame->id, (*dummy_id)))
- /* Stale -- destroy! */
- {
- dummy_frame_stack = dummy_frame->next;
- regcache_xfree (dummy_frame->regcache);
- xfree (dummy_frame);
- dummy_frame = dummy_frame_stack;
- }
- else
- dummy_frame = dummy_frame->next;
-
- dummy_frame = XZALLOC (struct dummy_frame);
- dummy_frame->regcache = caller_regcache;
- dummy_frame->id = (*dummy_id);
- dummy_frame->next = dummy_frame_stack;
- dummy_frame_stack = dummy_frame;
+ dp = lookup_dummy_frame (&id);
+ gdb_assert (dp != NULL);
+
+ pop_dummy_frame (dp);
+}
+
+/* Find the dummy frame by DUMMY_ID and PTID and drop it. Do nothing
+ if it is not found. Do not restore its state into inferior, just
+ free its memory. */
+
+void
+dummy_frame_discard (struct frame_id dummy_id, ptid_t ptid)
+{
+ struct dummy_frame **dp;
+ struct dummy_frame_id id = { dummy_id, ptid };
+
+ dp = lookup_dummy_frame (&id);
+ if (dp)
+ remove_dummy_frame (dp);
+}
+
+/* See dummy-frame.h. */
+
+void
+register_dummy_frame_dtor (struct frame_id dummy_id, ptid_t ptid,
+ dummy_frame_dtor_ftype *dtor, void *dtor_data)
+{
+ struct dummy_frame_id id = { dummy_id, ptid };
+ struct dummy_frame **dp, *d;
+ struct dummy_frame_dtor_list *list;
+
+ dp = lookup_dummy_frame (&id);
+ gdb_assert (dp != NULL);
+ d = *dp;
+ list = XNEW (struct dummy_frame_dtor_list);
+ list->next = d->dtor_list;
+ d->dtor_list = list;
+ list->dtor = dtor;
+ list->dtor_data = dtor_data;
+}
+
+/* See dummy-frame.h. */
+
+int
+find_dummy_frame_dtor (dummy_frame_dtor_ftype *dtor, void *dtor_data)
+{
+ struct dummy_frame *d;
+
+ for (d = dummy_frame_stack; d != NULL; d = d->next)
+ {
+ struct dummy_frame_dtor_list *list;
+
+ for (list = d->dtor_list; list != NULL; list = list->next)
+ if (list->dtor == dtor && list->dtor_data == dtor_data)
+ return 1;
+ }
+ return 0;
+}
+
+/* There may be stale dummy frames, perhaps left over from when an uncaught
+ longjmp took us out of a function that was called by the debugger. Clean
+ them up at least once whenever we start a new inferior. */
+
+static void
+cleanup_dummy_frames (struct target_ops *target, int from_tty)
+{
+ while (dummy_frame_stack != NULL)
+ remove_dummy_frame (&dummy_frame_stack);
}
/* Return the dummy frame cache, it contains both the ID, and a
struct regcache *prev_regcache;
};
-int
+static int
dummy_frame_sniffer (const struct frame_unwind *self,
- struct frame_info *next_frame,
+ struct frame_info *this_frame,
void **this_prologue_cache)
{
- struct dummy_frame *dummyframe;
- struct frame_id this_id;
-
/* When unwinding a normal frame, the stack structure is determined
by analyzing the frame's function's code (be it using brute force
prologue analysis, or the dwarf2 CFI). In the case of a dummy
entry point, or some random address on the stack. Trying to use
that PC to apply standard frame ID unwind techniques is just
asking for trouble. */
- /* Use an architecture specific method to extract the prev's dummy
- ID from the next frame. Note that this method uses
- frame_register_unwind to obtain the register values needed to
- determine the dummy frame's ID. */
- this_id = gdbarch_unwind_dummy_id (get_frame_arch (next_frame), next_frame);
-
- /* Use that ID to find the corresponding cache entry. */
- for (dummyframe = dummy_frame_stack;
- dummyframe != NULL;
- dummyframe = dummyframe->next)
+
+ /* Don't bother unless there is at least one dummy frame. */
+ if (dummy_frame_stack != NULL)
{
- if (frame_id_eq (dummyframe->id, this_id))
+ struct dummy_frame *dummyframe;
+ /* Use an architecture specific method to extract this frame's
+ dummy ID, assuming it is a dummy frame. */
+ struct frame_id this_id
+ = gdbarch_dummy_id (get_frame_arch (this_frame), this_frame);
+ struct dummy_frame_id dummy_id = { this_id, inferior_ptid };
+
+ /* Use that ID to find the corresponding cache entry. */
+ for (dummyframe = dummy_frame_stack;
+ dummyframe != NULL;
+ dummyframe = dummyframe->next)
{
- struct dummy_frame_cache *cache;
- cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache);
- cache->prev_regcache = dummyframe->regcache;
- cache->this_id = this_id;
- (*this_prologue_cache) = cache;
- return 1;
+ if (dummy_frame_id_eq (&dummyframe->id, &dummy_id))
+ {
+ struct dummy_frame_cache *cache;
+
+ cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache);
+ cache->prev_regcache = get_infcall_suspend_state_regcache
+ (dummyframe->caller_state);
+ cache->this_id = this_id;
+ (*this_prologue_cache) = cache;
+ return 1;
+ }
}
}
return 0;
/* Given a call-dummy dummy-frame, return the registers. Here the
register value is taken from the local copy of the register buffer. */
-static void
-dummy_frame_prev_register (struct frame_info *next_frame,
+static struct value *
+dummy_frame_prev_register (struct frame_info *this_frame,
void **this_prologue_cache,
- int regnum, int *optimized,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnum, void *bufferp)
+ int regnum)
{
+ struct dummy_frame_cache *cache
+ = (struct dummy_frame_cache *) *this_prologue_cache;
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct value *reg_val;
+
/* The dummy-frame sniffer always fills in the cache. */
- struct dummy_frame_cache *cache = (*this_prologue_cache);
gdb_assert (cache != NULL);
/* Describe the register's location. Generic dummy frames always
have the register value in an ``expression''. */
- *optimized = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnum = -1;
-
- /* If needed, find and return the value of the register. */
- if (bufferp != NULL)
- {
- /* Return the actual value. */
- /* Use the regcache_cooked_read() method so that it, on the fly,
- constructs either a raw or pseudo register from the raw
- register cache. */
- regcache_cooked_read (cache->prev_regcache, regnum, bufferp);
- }
+ reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
+
+ /* Use the regcache_cooked_read() method so that it, on the fly,
+ constructs either a raw or pseudo register from the raw
+ register cache. */
+ regcache_cooked_read (cache->prev_regcache, regnum,
+ value_contents_writeable (reg_val));
+ return reg_val;
}
-/* Assuming that THIS frame is a dummy (remember, the NEXT and not
- THIS frame is passed in), return the ID of THIS frame. That ID is
+/* Assuming that THIS_FRAME is a dummy, return its ID. That ID is
determined by examining the NEXT frame's unwound registers using
- the method unwind_dummy_id(). As a side effect, THIS dummy frame's
- dummy cache is located and and saved in THIS_PROLOGUE_CACHE. */
+ the method dummy_id(). As a side effect, THIS dummy frame's
+ dummy cache is located and saved in THIS_PROLOGUE_CACHE. */
static void
-dummy_frame_this_id (struct frame_info *next_frame,
+dummy_frame_this_id (struct frame_info *this_frame,
void **this_prologue_cache,
struct frame_id *this_id)
{
/* The dummy-frame sniffer always fills in the cache. */
- struct dummy_frame_cache *cache = (*this_prologue_cache);
+ struct dummy_frame_cache *cache
+ = (struct dummy_frame_cache *) *this_prologue_cache;
+
gdb_assert (cache != NULL);
(*this_id) = cache->this_id;
}
-static const struct frame_unwind dummy_frame_unwinder =
+const struct frame_unwind dummy_frame_unwind =
{
DUMMY_FRAME,
+ default_frame_unwind_stop_reason,
dummy_frame_this_id,
dummy_frame_prev_register,
NULL,
dummy_frame_sniffer,
};
-const struct frame_unwind *const dummy_frame_unwind = {
- &dummy_frame_unwinder
-};
-
static void
fprint_dummy_frames (struct ui_file *file)
{
struct dummy_frame *s;
+
for (s = dummy_frame_stack; s != NULL; s = s->next)
{
gdb_print_host_address (s, file);
fprintf_unfiltered (file, ":");
fprintf_unfiltered (file, " id=");
- fprint_frame_id (file, s->id);
+ fprint_frame_id (file, s->id.id);
+ fprintf_unfiltered (file, ", ptid=%s",
+ target_pid_to_str (s->id.ptid));
fprintf_unfiltered (file, "\n");
}
}
fprint_dummy_frames (gdb_stdout);
else
{
- struct ui_file *file = gdb_fopen (args, "w");
- if (file == NULL)
- perror_with_name ("maintenance print dummy-frames");
- fprint_dummy_frames (file);
- ui_file_delete (file);
+ stdio_file file;
+
+ if (!file.open (args, "w"))
+ perror_with_name (_("maintenance print dummy-frames"));
+ fprint_dummy_frames (&file);
}
}
_initialize_dummy_frame (void)
{
add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames,
- "Print the contents of the internal dummy-frame stack.",
+ _("Print the contents of the internal dummy-frame stack."),
&maintenanceprintlist);
+ observer_attach_inferior_created (cleanup_dummy_frames);
}