/* 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 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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
#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 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 + DECR_PC_AFTER_BREAK))
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 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 (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