/* 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, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
+ 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008
+ 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 "gdb_string.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;
-
- /* These values belong to the caller (the previous frame, the frame
- that this unwinds back to). */
- CORE_ADDR pc;
- CORE_ADDR fp;
- CORE_ADDR sp;
- CORE_ADDR top;
+ /* 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;
-
- /* 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;
};
static struct dummy_frame *dummy_frame_stack = NULL;
-/* Function: find_dummy_frame(pc, fp, sp)
-
- Search the stack of dummy frames for one matching the given PC and
- FP/SP. Unlike pc_in_dummy_frame(), 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. */
-
-static struct dummy_frame *
-find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
-{
- struct dummy_frame *dummyframe;
-
- for (dummyframe = dummy_frame_stack; dummyframe != NULL;
- dummyframe = dummyframe->next)
- {
- /* 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;
- }
-
- return NULL;
-}
-
-struct dummy_frame *
-cached_find_dummy_frame (struct frame_info *frame, void **cache)
-{
- if ((*cache) == NULL)
- (*cache) = find_dummy_frame (get_frame_pc (frame), get_frame_base (frame));
- return (*cache);
-}
-
-struct regcache *
-generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
-{
- struct dummy_frame *dummy = find_dummy_frame (pc, fp);
- if (dummy != NULL)
- return dummy->regcache;
- else
- return NULL;
-}
-
-char *
-deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
-{
- struct regcache *regcache = generic_find_dummy_frame (pc, fp);
- if (regcache == NULL)
- return NULL;
- return deprecated_grub_regcache_for_registers (regcache);
-}
-
-/* Function: pc_in_call_dummy (pc, sp, fp)
-
- 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. */
-
-int
-generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
-{
- return pc_in_dummy_frame (pc);
-}
-
-/* Return non-zero if the PC falls in a dummy frame.
+/* Function: deprecated_pc_in_call_dummy (pc)
- The code below which allows DECR_PC_AFTER_BREAK is for infrun.c,
- which may give the function a PC without that subtracted out.
+ 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.
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 (Oh, and I'm not even sure that this function
- is called with an decremented PC, the call to pc_in_call_dummy() in
- that file is conditional on !CALL_DUMMY_BREAKPOINT_OFFSET_P yet
- generic dummy targets set CALL_DUMMY_BREAKPOINT_OFFSET. True?). */
+ calling this function.
+
+ 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!
+
+ NOTE: cagney/2004-08-02: Code should not need to call this. */
int
-pc_in_dummy_frame (CORE_ADDR pc)
+deprecated_pc_in_call_dummy (CORE_ADDR pc)
{
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))
+ if ((pc >= dummyframe->id.code_addr)
+ && (pc <= dummyframe->id.code_addr
+ + gdbarch_decr_pc_after_break (current_gdbarch)))
return 1;
}
return 0;
}
-/* Function: read_register_dummy
- Find a saved register from before GDB calls a function in the inferior */
-
-CORE_ADDR
-deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
-{
- struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
-
- if (dummy_regs)
- {
- /* 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;
- }
- else
- return 0;
-}
-
-/* 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. */
+/* Push the caller's state, along with the dummy frame info, onto a
+ dummy-frame stack. */
void
-generic_push_dummy_frame (void)
+dummy_frame_push (struct regcache *caller_regcache,
+ const struct frame_id *dummy_id)
{
+ struct gdbarch *gdbarch = get_regcache_arch (caller_regcache);
struct dummy_frame *dummy_frame;
- CORE_ADDR fp = get_frame_base (get_current_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 */
+ /* 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! */
+ /* 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);
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;
- dummy_frame->id = get_frame_id (get_current_frame ());
- regcache_cpy (dummy_frame->regcache, current_regcache);
+ 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;
}
-void
-generic_save_dummy_frame_tos (CORE_ADDR sp)
+/* Return the dummy frame cache, it contains both the ID, and a
+ pointer to the regcache. */
+struct dummy_frame_cache
{
- dummy_frame_stack->top = sp;
-}
-
-/* Record the upper/lower bounds on the address of the call dummy. */
-
-void
-generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
-{
- dummy_frame_stack->call_lo = lo;
- dummy_frame_stack->call_hi = hi;
-}
-
-/* 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))
-{
- struct frame_info *frame = get_current_frame ();
- if (get_frame_type (frame) == DUMMY_FRAME)
- /* NOTE: cagney/2002-22-23: Does this ever occure? Surely a dummy
- frame will have already been poped by the "infrun.c" code. */
- generic_pop_dummy_frame ();
- else
- (*popper) (frame);
-}
-
-/* Function: pop_dummy_frame
- Restore the machine state from a saved dummy stack frame. */
-
-void
-generic_pop_dummy_frame (void)
-{
- struct dummy_frame *dummy_frame = dummy_frame_stack;
-
- /* 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? */
-
- 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);
-}
-
-/* Function: fix_call_dummy
- Stub function. Generic dummy frames typically do not need to fix
- the frame being created */
+ struct frame_id this_id;
+ struct regcache *prev_regcache;
+};
-void
-generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
- struct value **args, struct type *type, int gcc_p)
+int
+dummy_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *next_frame,
+ void **this_prologue_cache)
{
- return;
+ 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 unles 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);
+
+ /* 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 = dummyframe->regcache;
+ 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. */
-void
-dummy_frame_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
+dummy_frame_prev_register (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ int regnum, int *optimized,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnum, gdb_byte *bufferp)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
- gdb_assert (dummy != NULL);
+ /* 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''. */
/* 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 (dummy->regcache, regnum, bufferp);
+ regcache_cooked_read (cache->prev_regcache, regnum, bufferp);
}
}
-CORE_ADDR
-dummy_frame_pc_unwind (struct frame_info *frame,
- void **cache)
+/* 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
+ 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. */
+
+static void
+dummy_frame_this_id (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
- /* Oops! In a dummy-frame but can't find the stack dummy. Pretend
- that the frame doesn't unwind. Should this function instead
- return a has-no-caller indication? */
- if (dummy == NULL)
- return 0;
- return dummy->pc;
+ /* 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;
}
+static const struct frame_unwind dummy_frame_unwinder =
+{
+ DUMMY_FRAME,
+ dummy_frame_this_id,
+ dummy_frame_prev_register,
+ NULL,
+ dummy_frame_sniffer,
+};
-void
-dummy_frame_id_unwind (struct frame_info *frame, void **cache,
- struct frame_id *id)
+const struct frame_unwind *const dummy_frame_unwind = {
+ &dummy_frame_unwinder
+};
+
+static void
+fprint_dummy_frames (struct ui_file *file)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
- /* Oops! In a dummy-frame but can't find the stack dummy. Pretend
- that the frame doesn't unwind. Should this function instead
- return a has-no-caller indication? */
- if (dummy == NULL)
- (*id) = null_frame_id;
+ 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);
+ fprintf_unfiltered (file, "\n");
+ }
+}
+
+static void
+maintenance_print_dummy_frames (char *args, int from_tty)
+{
+ if (args == NULL)
+ fprint_dummy_frames (gdb_stdout);
else
- (*id) = dummy->id;
+ {
+ 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);
+ }
}
+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);
+
+}
projects / binutils.git / blobdiff