/* 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 Free Software
- Foundation, Inc.
+ Copyright (C) 1986-2014 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 "frame.h"
#include "inferior.h"
#include "gdb_assert.h"
+#include "frame-unwind.h"
+#include "command.h"
+#include "gdbcmd.h"
+#include <string.h>
+#include "observer.h"
+#include "gdbthread.h"
/* 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;
-
- CORE_ADDR pc;
- CORE_ADDR fp;
- CORE_ADDR sp;
- CORE_ADDR top;
- struct regcache *regcache;
-
- /* Address range of the call dummy code. Look for PC in the range
- [LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */
- CORE_ADDR call_lo;
- CORE_ADDR call_hi;
+ /* This frame's ID. Must match the value returned by
+ gdbarch_dummy_id. */
+ struct frame_id id;
+ /* The caller's state prior to the call. */
+ struct infcall_suspend_state *caller_state;
};
static struct dummy_frame *dummy_frame_stack = NULL;
-/* Function: find_dummy_frame(pc, fp, sp)
+/* Push the caller's state, along with the dummy frame info, onto the
+ dummy-frame stack. */
+
+void
+dummy_frame_push (struct infcall_suspend_state *caller_state,
+ const struct frame_id *dummy_id)
+{
+ struct dummy_frame *dummy_frame;
+
+ dummy_frame = XCNEW (struct dummy_frame);
+ dummy_frame->caller_state = caller_state;
+ dummy_frame->id = (*dummy_id);
+ dummy_frame->next = dummy_frame_stack;
+ dummy_frame_stack = dummy_frame;
+}
+
+/* Remove *DUMMY_PTR from the dummy frame stack. */
+
+static void
+remove_dummy_frame (struct dummy_frame **dummy_ptr)
+{
+ struct dummy_frame *dummy = *dummy_ptr;
+
+ *dummy_ptr = dummy->next;
+ discard_infcall_suspend_state (dummy->caller_state);
+ xfree (dummy);
+}
- Search the stack of dummy frames for one matching the given PC and
- FP/SP. Unlike PC_IN_CALL_DUMMY, this function doesn't need to
- adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
- to call this function after the PC has been adjusted. */
+/* Delete any breakpoint B which is a momentary breakpoint for return from
+ inferior call matching DUMMY_VOIDP. */
-struct regcache *
-generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
+static int
+pop_dummy_frame_bpt (struct breakpoint *b, void *dummy_voidp)
{
- struct dummy_frame *dummyframe;
+ struct dummy_frame *dummy = dummy_voidp;
- for (dummyframe = dummy_frame_stack; dummyframe != NULL;
- dummyframe = dummyframe->next)
+ if (b->thread == pid_to_thread_id (inferior_ptid)
+ && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id))
{
- /* Does the PC fall within the dummy frame's breakpoint
- instruction. If not, discard this one. */
- if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
- continue;
- /* Does the FP match? */
- if (dummyframe->top != 0)
- {
- /* If the target architecture explicitly saved the
- top-of-stack before the inferior function call, assume
- that that same architecture will always pass in an FP
- (frame base) value that eactly matches that saved TOS.
- Don't check the saved SP and SP as they can lead to false
- hits. */
- if (fp != dummyframe->top)
- continue;
- }
- else
- {
- /* An older target that hasn't explicitly or implicitly
- saved the dummy frame's top-of-stack. Try matching the
- FP against the saved SP and FP. NOTE: If you're trying
- to fix a problem with GDB not correctly finding a dummy
- frame, check the comments that go with FRAME_ALIGN() and
- SAVE_DUMMY_FRAME_TOS(). */
- if (fp != dummyframe->fp && fp != dummyframe->sp)
- continue;
- }
- /* The FP matches this dummy frame. */
- return dummyframe->regcache;
+ while (b->related_breakpoint != b)
+ delete_breakpoint (b->related_breakpoint);
+
+ delete_breakpoint (b);
+
+ /* Stop the traversal. */
+ return 1;
}
+ /* Continue the traversal. */
return 0;
}
-char *
-deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
+/* Pop *DUMMY_PTR, restoring program state to that before the
+ frame was created. */
+
+static void
+pop_dummy_frame (struct dummy_frame **dummy_ptr)
{
- struct regcache *regcache = generic_find_dummy_frame (pc, fp);
- if (regcache == NULL)
- return NULL;
- return deprecated_grub_regcache_for_registers (regcache);
-}
+ struct dummy_frame *dummy = *dummy_ptr;
-/* Function: pc_in_call_dummy (pc, sp, fp)
+ restore_infcall_suspend_state (dummy->caller_state);
- Return true 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. */
+ iterate_over_breakpoints (pop_dummy_frame_bpt, dummy);
-int
-generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
-{
- struct dummy_frame *dummyframe;
- for (dummyframe = dummy_frame_stack;
- dummyframe != NULL;
- dummyframe = dummyframe->next)
- {
- if ((pc >= dummyframe->call_lo)
- && (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
- return 1;
- }
- return 0;
+ /* 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 ();
}
-/* Function: read_register_dummy
- Find a saved register from before GDB calls a function in the inferior */
+/* Look up DUMMY_ID.
+ Return NULL if not found. */
-CORE_ADDR
-deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
+static struct dummy_frame **
+lookup_dummy_frame (struct frame_id dummy_id)
{
- struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
+ struct dummy_frame **dp;
- if (dummy_regs)
+ for (dp = &dummy_frame_stack; *dp != NULL; dp = &(*dp)->next)
{
- /* NOTE: cagney/2002-08-12: Replaced a call to
- regcache_raw_read_as_address() with a call to
- regcache_cooked_read_unsigned(). The old, ...as_address
- function was eventually calling extract_unsigned_integer (via
- extract_address) to unpack the registers value. The below is
- doing an unsigned extract so that it is functionally
- equivalent. The read needs to be cooked as, otherwise, it
- will never correctly return the value of a register in the
- [NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range. */
- ULONGEST val;
- regcache_cooked_read_unsigned (dummy_regs, regno, &val);
- return val;
+ if (frame_id_eq ((*dp)->id, dummy_id))
+ return dp;
}
- else
- return 0;
+
+ return NULL;
}
-/* Save all the registers on the dummy frame stack. Most ports save the
- registers on the target stack. This results in lots of unnecessary memory
- references, which are slow when debugging via a serial line. Instead, we
- save all the registers internally, and never write them to the stack. The
- registers get restored when the called function returns to the entry point,
- where a breakpoint is laying in wait. */
+/* Pop the dummy frame DUMMY_ID, 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.
+
+ NOTE: This can only pop the one frame, even if it is in the middle of the
+ stack, because the other frames may be for different threads, and there's
+ currently no way to tell which stack frame is for which thread. */
void
-generic_push_dummy_frame (void)
+dummy_frame_pop (struct frame_id dummy_id)
{
- struct dummy_frame *dummy_frame;
- CORE_ADDR fp = (get_current_frame ())->frame;
-
- /* 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)
- if (INNER_THAN (dummy_frame->fp, fp)) /* 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 = xmalloc (sizeof (struct dummy_frame));
- dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
-
- dummy_frame->pc = read_pc ();
- dummy_frame->sp = read_sp ();
- dummy_frame->top = 0;
- dummy_frame->fp = fp;
- regcache_cpy (dummy_frame->regcache, current_regcache);
- dummy_frame->next = dummy_frame_stack;
- dummy_frame_stack = dummy_frame;
+ struct dummy_frame **dp;
+
+ dp = lookup_dummy_frame (dummy_id);
+ gdb_assert (dp != NULL);
+
+ pop_dummy_frame (dp);
}
+/* Drop dummy frame DUMMY_ID. Do nothing if it is not found. Do not restore
+ its state into inferior, just free its memory. */
+
void
-generic_save_dummy_frame_tos (CORE_ADDR sp)
+dummy_frame_discard (struct frame_id dummy_id)
{
- dummy_frame_stack->top = sp;
+ struct dummy_frame **dp;
+
+ dp = lookup_dummy_frame (dummy_id);
+ if (dp)
+ remove_dummy_frame (dp);
}
-/* Record the upper/lower bounds on the address of the call dummy. */
+/* 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. */
-void
-generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
+static void
+cleanup_dummy_frames (struct target_ops *target, int from_tty)
{
- dummy_frame_stack->call_lo = lo;
- dummy_frame_stack->call_hi = hi;
+ while (dummy_frame_stack != NULL)
+ remove_dummy_frame (&dummy_frame_stack);
}
-/* Restore the machine state from either the saved dummy stack or a
- real stack frame. */
-
-void
-generic_pop_current_frame (void (*popper) (struct frame_info * frame))
+/* Return the dummy frame cache, it contains both the ID, and a
+ pointer to the regcache. */
+struct dummy_frame_cache
{
- struct frame_info *frame = get_current_frame ();
+ struct frame_id this_id;
+ struct regcache *prev_regcache;
+};
- if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
- generic_pop_dummy_frame ();
- else
- (*popper) (frame);
+static int
+dummy_frame_sniffer (const struct frame_unwind *self,
+ 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
+ frame, that simply isn't possible. The PC is either the program
+ 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. */
+
+ /* Don't bother unless there is at least one dummy frame. */
+ if (dummy_frame_stack != NULL)
+ {
+ /* Use an architecture specific method to extract this frame's
+ dummy ID, assuming it is a dummy frame. */
+ this_id = gdbarch_dummy_id (get_frame_arch (this_frame), this_frame);
+
+ /* 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))
+ {
+ 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;
}
-/* Function: pop_dummy_frame
- Restore the machine state from a saved dummy stack frame. */
+/* Given a call-dummy dummy-frame, return the registers. Here the
+ register value is taken from the local copy of the register buffer. */
-void
-generic_pop_dummy_frame (void)
+static struct value *
+dummy_frame_prev_register (struct frame_info *this_frame,
+ void **this_prologue_cache,
+ int regnum)
{
- struct dummy_frame *dummy_frame = dummy_frame_stack;
+ struct dummy_frame_cache *cache = (*this_prologue_cache);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct value *reg_val;
- /* FIXME: what if the first frame isn't the right one, eg..
- because one call-by-hand function has done a longjmp into another one? */
+ /* The dummy-frame sniffer always fills in the cache. */
+ gdb_assert (cache != NULL);
- if (!dummy_frame)
- error ("Can't pop dummy frame!");
- dummy_frame_stack = dummy_frame->next;
- regcache_cpy (current_regcache, dummy_frame->regcache);
- flush_cached_frames ();
-
- regcache_xfree (dummy_frame->regcache);
- xfree (dummy_frame);
+ /* Describe the register's location. Generic dummy frames always
+ have the register value in an ``expression''. */
+ 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;
}
-/* Function: fix_call_dummy
- Stub function. Generic dummy frames typically do not need to fix
- the frame being created */
+/* 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 dummy_id(). As a side effect, THIS dummy frame's
+ dummy cache is located and saved in THIS_PROLOGUE_CACHE. */
-void
-generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
- struct value **args, struct type *type, int gcc_p)
+static void
+dummy_frame_this_id (struct frame_info *this_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
{
- return;
+ /* The dummy-frame sniffer always fills in the cache. */
+ struct dummy_frame_cache *cache = (*this_prologue_cache);
+
+ gdb_assert (cache != NULL);
+ (*this_id) = cache->this_id;
}
-/* Given a call-dummy dummy-frame, return the registers. Here the
- register value is taken from the local copy of the register buffer. */
+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,
+};
-void
-generic_call_dummy_register_unwind (struct frame_info *frame, void **cache,
- int regnum, int *optimized,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnum, void *bufferp)
+static void
+fprint_dummy_frames (struct ui_file *file)
{
- gdb_assert (frame != NULL);
- gdb_assert (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame));
+ struct dummy_frame *s;
- /* 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;
+ 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);
+ fprintf_unfiltered (file, "\n");
+ }
+}
- /* If needed, find and return the value of the register. */
- if (bufferp != NULL)
+static void
+maintenance_print_dummy_frames (char *args, int from_tty)
+{
+ if (args == NULL)
+ fprint_dummy_frames (gdb_stdout);
+ else
{
- struct regcache *registers;
-#if 1
- /* Get the address of the register buffer that contains all the
- saved registers for this dummy frame. Cache that address. */
- registers = (*cache);
- if (registers == NULL)
- {
- registers = generic_find_dummy_frame (frame->pc, frame->frame);
- (*cache) = registers;
- }
-#else
- /* Get the address of the register buffer that contains the
- saved registers and then extract the value from that. */
- registers = generic_find_dummy_frame (frame->pc, frame->frame);
-#endif
- gdb_assert (registers != 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 (registers, regnum, bufferp);
+ struct cleanup *cleanups;
+ struct ui_file *file = gdb_fopen (args, "w");
+
+ if (file == NULL)
+ perror_with_name (_("maintenance print dummy-frames"));
+ cleanups = make_cleanup_ui_file_delete (file);
+ fprint_dummy_frames (file);
+ do_cleanups (cleanups);
}
}
+extern void _initialize_dummy_frame (void);
+
+void
+_initialize_dummy_frame (void)
+{
+ add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames,
+ _("Print the contents of the internal dummy-frame stack."),
+ &maintenanceprintlist);
+
+ observer_attach_inferior_created (cleanup_dummy_frames);
+}
projects / deliverable / binutils-gdb.git / blobdiff