/* Code dealing with dummy stack frames, for GDB, the GNU debugger.
- Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008
- Free Software Foundation, Inc.
+ Copyright (C) 1986-2019 Free Software Foundation, Inc.
This file is part of GDB.
#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 "observable.h"
+#include "gdbthread.h"
+#include "infcall.h"
+#include "gdbarch.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. */
+ thread_info *thread;
+};
+
+/* 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) && id1->thread == id2->thread;
+}
+
+/* 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 gdbarch_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 frame_id *dummy_id, thread_info *thread)
+{
+ 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.thread = thread;
+ 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 bool
+pop_dummy_frame_bpt (struct breakpoint *b, struct dummy_frame *dummy)
{
- struct dummy_frame *dummyframe;
- for (dummyframe = dummy_frame_stack;
- dummyframe != NULL;
- dummyframe = dummyframe->next)
+ if (b->thread == dummy->id.thread->global_num
+ && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id.id))
{
- if ((pc >= dummyframe->id.code_addr)
- && (pc <= dummyframe->id.code_addr
- + gdbarch_decr_pc_after_break (current_gdbarch)))
- return 1;
+ while (b->related_breakpoint != b)
+ delete_breakpoint (b->related_breakpoint);
+
+ delete_breakpoint (b);
+
+ /* Stop the traversal. */
+ return true;
}
- return 0;
+
+ /* Continue the traversal. */
+ return false;
}
-/* 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 (dummy->id.thread == inferior_thread ());
+
+ 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 ([dummy] (breakpoint* bp)
+ {
+ return pop_dummy_frame_bpt (bp, 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 THREAD, 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 (frame_id dummy_id, thread_info *thread)
{
- struct gdbarch *gdbarch = get_regcache_arch (caller_regcache);
- struct dummy_frame *dummy_frame;
+ struct dummy_frame **dp;
+ struct dummy_frame_id id = { dummy_id, thread };
- /* 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 (gdbarch, 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, thread_info *thread)
+{
+ struct dummy_frame **dp;
+ struct dummy_frame_id id = { dummy_id, thread };
+
+ dp = lookup_dummy_frame (&id);
+ if (dp)
+ remove_dummy_frame (dp);
+}
+
+/* See dummy-frame.h. */
+
+void
+register_dummy_frame_dtor (frame_id dummy_id, thread_info *thread,
+ dummy_frame_dtor_ftype *dtor, void *dtor_data)
+{
+ struct dummy_frame_id id = { dummy_id, thread };
+ 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 dummy_frame_cache
{
struct frame_id this_id;
- struct regcache *prev_regcache;
+ readonly_detached_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
that PC to apply standard frame ID unwind techniques is just
asking for trouble. */
- /* Don't bother unles there is at least one dummy frame. */
+ /* Don't bother unless there is at least one dummy frame. */
if (dummy_frame_stack != NULL)
{
- /* 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);
+ 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_thread () };
/* Use that ID to find the corresponding cache entry. */
for (dummyframe = dummy_frame_stack;
dummyframe != NULL;
dummyframe = dummyframe->next)
{
- if (frame_id_eq (dummyframe->id, this_id))
+ 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 = dummyframe->regcache;
+ cache->prev_regcache = get_infcall_suspend_state_regcache
+ (dummyframe->caller_state);
cache->this_id = this_id;
(*this_prologue_cache) = cache;
return 1;
/* 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, gdb_byte *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. */
+ cache->prev_regcache->cooked_read (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
-};
+/* See dummy-frame.h. */
+
+struct frame_id
+default_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ CORE_ADDR sp, pc;
+
+ sp = get_frame_sp (this_frame);
+ pc = get_frame_pc (this_frame);
+ return frame_id_build (sp, pc);
+}
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.thread->ptid).c_str ());
fprintf_unfiltered (file, "\n");
}
}
static void
-maintenance_print_dummy_frames (char *args, int from_tty)
+maintenance_print_dummy_frames (const char *args, int from_tty)
{
if (args == NULL)
fprint_dummy_frames (gdb_stdout);
else
{
- struct ui_file *file = gdb_fopen (args, "w");
- if (file == NULL)
+ stdio_file file;
+
+ if (!file.open (args, "w"))
perror_with_name (_("maintenance print dummy-frames"));
- fprint_dummy_frames (file);
- ui_file_delete (file);
+ fprint_dummy_frames (&file);
}
}
-extern void _initialize_dummy_frame (void);
-
void
_initialize_dummy_frame (void)
{
_("Print the contents of the internal dummy-frame stack."),
&maintenanceprintlist);
+ gdb::observers::inferior_created.attach (cleanup_dummy_frames);
}