/* Cache and manage frames for GDB, the GNU debugger.
Copyright (C) 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001,
- 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
+ 2002, 2003, 2004, 2007, 2008, 2009 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., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "frame.h"
#include "observer.h"
#include "objfiles.h"
#include "exceptions.h"
+#include "gdbthread.h"
static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
/* Flag to control debugging. */
-static int frame_debug;
+int frame_debug;
static void
show_frame_debug (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
fi->level);
/* Find the unwinder. */
if (fi->unwind == NULL)
- fi->unwind = frame_unwind_find_by_frame (fi->next,
- &fi->prologue_cache);
+ fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache);
/* Find THIS frame's ID. */
- fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
+ fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value);
fi->this_id.p = 1;
if (frame_debug)
{
return eq;
}
-int
-frame_id_inner (struct frame_id l, struct frame_id r)
+/* Safety net to check whether frame ID L should be inner to
+ frame ID R, according to their stack addresses.
+
+ This method cannot be used to compare arbitrary frames, as the
+ ranges of valid stack addresses may be discontiguous (e.g. due
+ to sigaltstack).
+
+ However, it can be used as safety net to discover invalid frame
+ IDs in certain circumstances.
+
+ * If frame NEXT is the immediate inner frame to THIS, and NEXT
+ is a NORMAL frame, then the stack address of NEXT must be
+ inner-than-or-equal to the stack address of THIS.
+
+ Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind
+ error has occurred.
+
+ * If frame NEXT is the immediate inner frame to THIS, and NEXT
+ is a NORMAL frame, and NEXT and THIS have different stack
+ addresses, no other frame in the frame chain may have a stack
+ address in between.
+
+ Therefore, if frame_id_inner (TEST, THIS) holds, but
+ frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer
+ to a valid frame in the frame chain. */
+
+static int
+frame_id_inner (struct gdbarch *gdbarch, struct frame_id l, struct frame_id r)
{
int inner;
if (!l.stack_addr_p || !r.stack_addr_p)
comment in "frame.h", there is some fuzz here. Frameless
functions are not strictly inner than (same .stack but
different .code and/or .special address). */
- inner = INNER_THAN (l.stack_addr, r.stack_addr);
+ inner = gdbarch_inner_than (gdbarch, l.stack_addr, r.stack_addr);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l=");
struct frame_info *
frame_find_by_id (struct frame_id id)
{
- struct frame_info *frame;
+ struct frame_info *frame, *prev_frame;
/* ZERO denotes the null frame, let the caller decide what to do
about it. Should it instead return get_current_frame()? */
if (!frame_id_p (id))
return NULL;
- for (frame = get_current_frame ();
- frame != NULL;
- frame = get_prev_frame (frame))
+ for (frame = get_current_frame (); ; frame = prev_frame)
{
struct frame_id this = get_frame_id (frame);
if (frame_id_eq (id, this))
/* An exact match. */
return frame;
- if (frame_id_inner (id, this))
- /* Gone to far. */
+
+ prev_frame = get_prev_frame (frame);
+ if (!prev_frame)
+ return NULL;
+
+ /* As a safety net to avoid unnecessary backtracing while trying
+ to find an invalid ID, we check for a common situation where
+ we can detect from comparing stack addresses that no other
+ frame in the current frame chain can have this ID. See the
+ comment at frame_id_inner for details. */
+ if (get_frame_type (frame) == NORMAL_FRAME
+ && !frame_id_inner (get_frame_arch (frame), id, this)
+ && frame_id_inner (get_frame_arch (prev_frame), id,
+ get_frame_id (prev_frame)))
return NULL;
- /* Either we're not yet gone far enough out along the frame
- chain (inner(this,id)), or we're comparing frameless functions
- (same .base, different .func, no test available). Struggle
- on until we've definitly gone to far. */
}
return NULL;
}
if (!this_frame->prev_pc.p)
{
CORE_ADDR pc;
- if (this_frame->unwind == NULL)
- this_frame->unwind
- = frame_unwind_find_by_frame (this_frame->next,
- &this_frame->prologue_cache);
- if (this_frame->unwind->prev_pc != NULL)
- /* A per-frame unwinder, prefer it. */
- pc = this_frame->unwind->prev_pc (this_frame->next,
- &this_frame->prologue_cache);
- else if (gdbarch_unwind_pc_p (current_gdbarch))
+ if (gdbarch_unwind_pc_p (get_frame_arch (this_frame)))
{
/* The right way. The `pure' way. The one true way. This
method depends solely on the register-unwind code to
frame. This is all in stark contrast to the old
FRAME_SAVED_PC which would try to directly handle all the
different ways that a PC could be unwound. */
- pc = gdbarch_unwind_pc (current_gdbarch, this_frame);
+ pc = gdbarch_unwind_pc (get_frame_arch (this_frame), this_frame);
}
else
internal_error (__FILE__, __LINE__, _("No unwind_pc method"));
}
CORE_ADDR
-frame_func_unwind (struct frame_info *fi)
+get_frame_func (struct frame_info *this_frame)
{
- if (!fi->prev_func.p)
+ struct frame_info *next_frame = this_frame->next;
+
+ if (!next_frame->prev_func.p)
{
/* Make certain that this, and not the adjacent, function is
found. */
- CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi);
- fi->prev_func.p = 1;
- fi->prev_func.addr = get_pc_function_start (addr_in_block);
+ CORE_ADDR addr_in_block = get_frame_address_in_block (this_frame);
+ next_frame->prev_func.p = 1;
+ next_frame->prev_func.addr = get_pc_function_start (addr_in_block);
if (frame_debug)
fprintf_unfiltered (gdb_stdlog,
- "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
- fi->level, paddr_nz (fi->prev_func.addr));
+ "{ get_frame_func (this_frame=%d) -> 0x%s }\n",
+ this_frame->level,
+ paddr_nz (next_frame->prev_func.addr));
}
- return fi->prev_func.addr;
-}
-
-CORE_ADDR
-get_frame_func (struct frame_info *fi)
-{
- return frame_func_unwind (fi->next);
+ return next_frame->prev_func.addr;
}
static int
do_frame_register_read (void *src, int regnum, gdb_byte *buf)
{
- frame_register_read (src, regnum, buf);
- return 1;
+ return frame_register_read (src, regnum, buf);
}
struct regcache *
frame_save_as_regcache (struct frame_info *this_frame)
{
- struct regcache *regcache = regcache_xmalloc (current_gdbarch);
+ struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame));
struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
regcache_save (regcache, do_frame_register_read, this_frame);
discard_cleanups (cleanups);
void
frame_pop (struct frame_info *this_frame)
{
+ struct frame_info *prev_frame;
+ struct regcache *scratch;
+ struct cleanup *cleanups;
+
+ /* Ensure that we have a frame to pop to. */
+ prev_frame = get_prev_frame_1 (this_frame);
+
+ if (!prev_frame)
+ error (_("Cannot pop the initial frame."));
+
/* Make a copy of all the register values unwound from this frame.
Save them in a scratch buffer so that there isn't a race between
- trying to extract the old values from the current_regcache while
+ trying to extract the old values from the current regcache while
at the same time writing new values into that same cache. */
- struct regcache *scratch
- = frame_save_as_regcache (get_prev_frame_1 (this_frame));
- struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch);
+ scratch = frame_save_as_regcache (prev_frame);
+ cleanups = make_cleanup_regcache_xfree (scratch);
+
+ /* If we are popping a dummy frame, clean up the associated
+ data as well. */
+ if (get_frame_type (this_frame) == DUMMY_FRAME)
+ dummy_frame_pop (get_frame_id (this_frame));
/* FIXME: cagney/2003-03-16: It should be possible to tell the
target's register cache that it is about to be hit with a burst
(arguably a bug in the target code mind). */
/* Now copy those saved registers into the current regcache.
Here, regcache_cpy() calls regcache_restore(). */
- regcache_cpy (current_regcache, scratch);
+ regcache_cpy (get_current_regcache (), scratch);
do_cleanups (cleanups);
/* We've made right mess of GDB's local state, just discard
everything. */
- flush_cached_frames ();
+ reinit_frame_cache ();
}
void
int *optimizedp, enum lval_type *lvalp,
CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
{
- struct frame_unwind_cache *cache;
-
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "\
-{ frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
- frame->level, regnum,
- frame_map_regnum_to_name (frame, regnum));
- }
+ struct value *value;
/* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
that the value proper does not need to be fetched. */
gdb_assert (realnump != NULL);
/* gdb_assert (bufferp != NULL); */
- /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
- is broken. There is always a frame. If there, for some reason,
- isn't a frame, there is some pretty busted code as it should have
- detected the problem before calling here. */
- gdb_assert (frame != NULL);
+ value = frame_unwind_register_value (frame, regnum);
- /* Find the unwinder. */
- if (frame->unwind == NULL)
- frame->unwind = frame_unwind_find_by_frame (frame->next,
- &frame->prologue_cache);
+ gdb_assert (value != NULL);
- /* Ask this frame to unwind its register. See comment in
- "frame-unwind.h" for why NEXT frame and this unwind cache are
- passed in. */
- frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
- optimizedp, lvalp, addrp, realnump, bufferp);
+ *optimizedp = value_optimized_out (value);
+ *lvalp = VALUE_LVAL (value);
+ *addrp = VALUE_ADDRESS (value);
+ *realnump = VALUE_REGNUM (value);
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "->");
- fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp));
- fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp));
- fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp)));
- fprintf_unfiltered (gdb_stdlog, " *bufferp=");
- if (bufferp == NULL)
- fprintf_unfiltered (gdb_stdlog, "<NULL>");
- else
- {
- int i;
- const unsigned char *buf = bufferp;
- fprintf_unfiltered (gdb_stdlog, "[");
- for (i = 0; i < register_size (current_gdbarch, regnum); i++)
- fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
- fprintf_unfiltered (gdb_stdlog, "]");
- }
- fprintf_unfiltered (gdb_stdlog, " }\n");
- }
+ if (bufferp)
+ memcpy (bufferp, value_contents_all (value),
+ TYPE_LENGTH (value_type (value)));
+
+ /* Dispose of the new value. This prevents watchpoints from
+ trying to watch the saved frame pointer. */
+ release_value (value);
+ value_free (value);
}
void
frame_unwind_register (frame->next, regnum, buf);
}
+struct value *
+frame_unwind_register_value (struct frame_info *frame, int regnum)
+{
+ struct value *value;
+
+ gdb_assert (frame != NULL);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "\
+{ frame_unwind_register_value (frame=%d,regnum=%d(%s),...) ",
+ frame->level, regnum,
+ user_reg_map_regnum_to_name
+ (get_frame_arch (frame), regnum));
+ }
+
+ /* Find the unwinder. */
+ if (frame->unwind == NULL)
+ frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache);
+
+ /* Ask this frame to unwind its register. */
+ value = frame->unwind->prev_register (frame, &frame->prologue_cache, regnum);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "->");
+ if (value_optimized_out (value))
+ fprintf_unfiltered (gdb_stdlog, " optimized out");
+ else
+ {
+ if (VALUE_LVAL (value) == lval_register)
+ fprintf_unfiltered (gdb_stdlog, " register=%d",
+ VALUE_REGNUM (value));
+ else if (VALUE_LVAL (value) == lval_memory)
+ fprintf_unfiltered (gdb_stdlog, " address=0x%s",
+ paddr_nz (VALUE_ADDRESS (value)));
+ else
+ fprintf_unfiltered (gdb_stdlog, " computed");
+
+ if (value_lazy (value))
+ fprintf_unfiltered (gdb_stdlog, " lazy");
+ else
+ {
+ int i;
+ const gdb_byte *buf = value_contents (value);
+
+ fprintf_unfiltered (gdb_stdlog, " bytes=");
+ fprintf_unfiltered (gdb_stdlog, "[");
+ for (i = 0; i < register_size (get_frame_arch (frame), regnum); i++)
+ fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
+ fprintf_unfiltered (gdb_stdlog, "]");
+ }
+ }
+
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
+
+ return value;
+}
+
+struct value *
+get_frame_register_value (struct frame_info *frame, int regnum)
+{
+ return frame_unwind_register_value (frame->next, regnum);
+}
+
LONGEST
frame_unwind_register_signed (struct frame_info *frame, int regnum)
{
return frame_unwind_register_unsigned (frame->next, regnum);
}
-void
-frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
- ULONGEST *val)
-{
- gdb_byte buf[MAX_REGISTER_SIZE];
- frame_unwind_register (frame, regnum, buf);
- (*val) = extract_unsigned_integer (buf,
- register_size (get_frame_arch (frame),
- regnum));
-}
-
void
put_frame_register (struct frame_info *frame, int regnum,
const gdb_byte *buf)
break;
}
case lval_register:
- regcache_cooked_write (current_regcache, realnum, buf);
+ regcache_cooked_write (get_current_regcache (), realnum, buf);
break;
default:
error (_("Attempt to assign to an unmodifiable value."));
int realnum;
frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
- /* FIXME: cagney/2002-05-15: This test is just bogus.
-
- It indicates that the target failed to supply a value for a
- register because it was "not available" at this time. Problem
- is, the target still has the register and so get saved_register()
- may be returning a value saved on the stack. */
-
- if (register_cached (regnum) < 0)
- return 0; /* register value not available */
-
return !optimized;
}
CORE_ADDR offset, int len, gdb_byte *myaddr)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
+ int i;
+ int maxsize;
+ int numregs;
/* Skip registers wholly inside of OFFSET. */
while (offset >= register_size (gdbarch, regnum))
regnum++;
}
+ /* Ensure that we will not read beyond the end of the register file.
+ This can only ever happen if the debug information is bad. */
+ maxsize = -offset;
+ numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
+ for (i = regnum; i < numregs; i++)
+ {
+ int thissize = register_size (gdbarch, i);
+ if (thissize == 0)
+ break; /* This register is not available on this architecture. */
+ maxsize += thissize;
+ }
+ if (len > maxsize)
+ {
+ warning (_("Bad debug information detected: "
+ "Attempt to read %d bytes from registers."), len);
+ return 0;
+ }
+
/* Copy the data. */
while (len > 0)
{
memcpy (myaddr, buf + offset, curr_len);
}
+ myaddr += curr_len;
len -= curr_len;
offset = 0;
regnum++;
put_frame_register (frame, regnum, buf);
}
+ myaddr += curr_len;
len -= curr_len;
offset = 0;
regnum++;
}
}
-/* Map between a frame register number and its name. A frame register
- space is a superset of the cooked register space --- it also
- includes builtin registers. */
-
-int
-frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len)
-{
- return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len);
-}
-
-const char *
-frame_map_regnum_to_name (struct frame_info *frame, int regnum)
-{
- return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum);
-}
-
/* Create a sentinel frame. */
static struct frame_info *
error (_("No stack."));
if (!target_has_memory)
error (_("No memory."));
+ if (is_executing (inferior_ptid))
+ error (_("Target is executing."));
+
if (current_frame == NULL)
{
struct frame_info *sentinel_frame =
- create_sentinel_frame (current_regcache);
+ create_sentinel_frame (get_current_regcache ());
if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame,
RETURN_MASK_ERROR) != 0)
{
/* The "selected" stack frame is used by default for local and arg
access. May be zero, for no selected frame. */
-struct frame_info *deprecated_selected_frame;
+static struct frame_info *selected_frame;
+
+static int
+has_stack_frames (void)
+{
+ if (!target_has_registers || !target_has_stack || !target_has_memory)
+ return 0;
+
+ /* If the current thread is executing, don't try to read from
+ it. */
+ if (is_executing (inferior_ptid))
+ return 0;
+
+ return 1;
+}
/* Return the selected frame. Always non-NULL (unless there isn't an
inferior sufficient for creating a frame) in which case an error is
struct frame_info *
get_selected_frame (const char *message)
{
- if (deprecated_selected_frame == NULL)
+ if (selected_frame == NULL)
{
- if (message != NULL && (!target_has_registers
- || !target_has_stack
- || !target_has_memory))
+ if (message != NULL && !has_stack_frames ())
error (("%s"), message);
/* Hey! Don't trust this. It should really be re-finding the
last selected frame of the currently selected thread. This,
select_frame (get_current_frame ());
}
/* There is always a frame. */
- gdb_assert (deprecated_selected_frame != NULL);
- return deprecated_selected_frame;
+ gdb_assert (selected_frame != NULL);
+ return selected_frame;
}
/* This is a variant of get_selected_frame() which can be called when
struct frame_info *
deprecated_safe_get_selected_frame (void)
{
- if (!target_has_registers || !target_has_stack || !target_has_memory)
+ if (!has_stack_frames ())
return NULL;
return get_selected_frame (NULL);
}
{
struct symtab *s;
- deprecated_selected_frame = fi;
+ selected_frame = fi;
/* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
frame is being invalidated. */
if (deprecated_selected_frame_level_changed_hook)
fi = FRAME_OBSTACK_ZALLOC (struct frame_info);
- fi->next = create_sentinel_frame (current_regcache);
+ fi->next = create_sentinel_frame (get_current_regcache ());
/* Select/initialize both the unwind function and the frame's type
based on the PC. */
- fi->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
+ fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache);
fi->this_id.p = 1;
deprecated_update_frame_base_hack (fi, addr);
void
frame_observer_target_changed (struct target_ops *target)
{
- flush_cached_frames ();
+ reinit_frame_cache ();
}
/* Flush the entire frame cache. */
void
-flush_cached_frames (void)
+reinit_frame_cache (void)
{
+ struct frame_info *fi;
+
+ /* Tear down all frame caches. */
+ for (fi = current_frame; fi != NULL; fi = fi->prev)
+ {
+ if (fi->prologue_cache && fi->unwind->dealloc_cache)
+ fi->unwind->dealloc_cache (fi, fi->prologue_cache);
+ if (fi->base_cache && fi->base->unwind->dealloc_cache)
+ fi->base->unwind->dealloc_cache (fi, fi->base_cache);
+ }
+
/* Since we can't really be sure what the first object allocated was */
obstack_free (&frame_cache_obstack, 0);
obstack_init (&frame_cache_obstack);
+ if (current_frame != NULL)
+ annotate_frames_invalid ();
+
current_frame = NULL; /* Invalidate cache */
select_frame (NULL);
- annotate_frames_invalid ();
if (frame_debug)
- fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n");
-}
-
-/* Flush the frame cache, and start a new one if necessary. */
-
-void
-reinit_frame_cache (void)
-{
- flush_cached_frames ();
-
- /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
- if (PIDGET (inferior_ptid) != 0)
- {
- select_frame (get_current_frame ());
- }
+ fprintf_unfiltered (gdb_stdlog, "{ reinit_frame_cache () }\n");
}
/* Find where a register is saved (in memory or another register).
{
struct frame_info *prev_frame;
struct frame_id this_id;
+ struct gdbarch *gdbarch;
gdb_assert (this_frame != NULL);
+ gdbarch = get_frame_arch (this_frame);
if (frame_debug)
{
}
return this_frame->prev;
}
+
+ /* If the frame unwinder hasn't been selected yet, we must do so
+ before setting prev_p; otherwise the check for misbehaved
+ sniffers will think that this frame's sniffer tried to unwind
+ further (see frame_cleanup_after_sniffer). */
+ if (this_frame->unwind == NULL)
+ this_frame->unwind
+ = frame_unwind_find_by_frame (this_frame, &this_frame->prologue_cache);
+
this_frame->prev_p = 1;
this_frame->stop_reason = UNWIND_NO_REASON;
/* Check that this frame's ID isn't inner to (younger, below, next)
the next frame. This happens when a frame unwind goes backwards.
- Exclude signal trampolines (due to sigaltstack the frame ID can
- go backwards) and sentinel frames (the test is meaningless). */
- if (this_frame->next->level >= 0
- && this_frame->next->unwind->type != SIGTRAMP_FRAME
- && frame_id_inner (this_id, get_frame_id (this_frame->next)))
+ This check is valid only if the next frame is NORMAL. See the
+ comment at frame_id_inner for details. */
+ if (this_frame->next->unwind->type == NORMAL_FRAME
+ && frame_id_inner (get_frame_arch (this_frame->next), this_id,
+ get_frame_id (this_frame->next)))
{
if (frame_debug)
{
have different frame IDs, the new frame will be bogus; two
functions can't share a register save slot for the PC. This can
happen when the prologue analyzer finds a stack adjustment, but
- no PC save. This check does assume that the "PC register" is
- roughly a traditional PC, even if the gdbarch_unwind_pc method
- frobs it. */
+ no PC save.
+
+ This check does assume that the "PC register" is roughly a
+ traditional PC, even if the gdbarch_unwind_pc method adjusts
+ it (we do not rely on the value, only on the unwound PC being
+ dependent on this value). A potential improvement would be
+ to have the frame prev_pc method and the gdbarch unwind_pc
+ method set the same lval and location information as
+ frame_register_unwind. */
if (this_frame->level > 0
+ && gdbarch_pc_regnum (gdbarch) >= 0
&& get_frame_type (this_frame) == NORMAL_FRAME
&& get_frame_type (this_frame->next) == NORMAL_FRAME)
{
- int optimized, realnum;
+ int optimized, realnum, nrealnum;
enum lval_type lval, nlval;
CORE_ADDR addr, naddr;
- frame_register_unwind_location (this_frame, PC_REGNUM, &optimized,
- &lval, &addr, &realnum);
- frame_register_unwind_location (get_next_frame (this_frame), PC_REGNUM,
- &optimized, &nlval, &naddr, &realnum);
+ frame_register_unwind_location (this_frame,
+ gdbarch_pc_regnum (gdbarch),
+ &optimized, &lval, &addr, &realnum);
+ frame_register_unwind_location (get_next_frame (this_frame),
+ gdbarch_pc_regnum (gdbarch),
+ &optimized, &nlval, &naddr, &nrealnum);
- if (lval == lval_memory && lval == nlval && addr == naddr)
+ if ((lval == lval_memory && lval == nlval && addr == naddr)
+ || (lval == lval_register && lval == nlval && realnum == nrealnum))
{
if (frame_debug)
{
/* Debug routine to print a NULL frame being returned. */
static void
-frame_debug_got_null_frame (struct ui_file *file,
- struct frame_info *this_frame,
+frame_debug_got_null_frame (struct frame_info *this_frame,
const char *reason)
{
if (frame_debug)
return 0;
/* Make certain that the code, and not descriptor, address is
returned. */
- maddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+ maddr = gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame),
SYMBOL_VALUE_ADDRESS (msymbol),
¤t_target);
return maddr == get_frame_func (this_frame);
Per the above, this code shouldn't even be called with a NULL
THIS_FRAME. */
- frame_debug_got_null_frame (gdb_stdlog, this_frame, "this_frame NULL");
+ frame_debug_got_null_frame (this_frame, "this_frame NULL");
return current_frame;
}
user later decides to enable unwinds past main(), that will
automatically happen. */
{
- frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside main func");
+ frame_debug_got_null_frame (this_frame, "inside main func");
return NULL;
}
frame. */
if (this_frame->level + 2 > backtrace_limit)
{
- frame_debug_got_null_frame (gdb_stdlog, this_frame,
- "backtrace limit exceeded");
+ frame_debug_got_null_frame (this_frame, "backtrace limit exceeded");
return NULL;
}
&& get_frame_type (this_frame) != DUMMY_FRAME && this_frame->level >= 0
&& inside_entry_func (this_frame))
{
- frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
+ frame_debug_got_null_frame (this_frame, "inside entry func");
return NULL;
}
&& get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME
&& get_frame_pc (this_frame) == 0)
{
- frame_debug_got_null_frame (gdb_stdlog, this_frame, "zero PC");
+ frame_debug_got_null_frame (this_frame, "zero PC");
return NULL;
}
return frame_pc_unwind (frame->next);
}
-/* Return an address of that falls within the frame's code block. */
+/* Return an address that falls within THIS_FRAME's code block. */
CORE_ADDR
-frame_unwind_address_in_block (struct frame_info *next_frame)
+get_frame_address_in_block (struct frame_info *this_frame)
{
/* A draft address. */
- CORE_ADDR pc = frame_pc_unwind (next_frame);
-
- /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
- and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
- frame's PC ends up pointing at the instruction fallowing the
- "call". Adjust that PC value so that it falls on the call
- instruction (which, hopefully, falls within THIS frame's code
- block. So far it's proved to be a very good approximation. See
- get_frame_type() for why ->type can't be used. */
- if (next_frame->level >= 0
- && get_frame_type (next_frame) == NORMAL_FRAME)
- --pc;
- return pc;
-}
+ CORE_ADDR pc = get_frame_pc (this_frame);
+
+ struct frame_info *next_frame = this_frame->next;
+
+ /* Calling get_frame_pc returns the resume address for THIS_FRAME.
+ Normally the resume address is inside the body of the function
+ associated with THIS_FRAME, but there is a special case: when
+ calling a function which the compiler knows will never return
+ (for instance abort), the call may be the very last instruction
+ in the calling function. The resume address will point after the
+ call and may be at the beginning of a different function
+ entirely.
+
+ If THIS_FRAME is a signal frame or dummy frame, then we should
+ not adjust the unwound PC. For a dummy frame, GDB pushed the
+ resume address manually onto the stack. For a signal frame, the
+ OS may have pushed the resume address manually and invoked the
+ handler (e.g. GNU/Linux), or invoked the trampoline which called
+ the signal handler - but in either case the signal handler is
+ expected to return to the trampoline. So in both of these
+ cases we know that the resume address is executable and
+ related. So we only need to adjust the PC if THIS_FRAME
+ is a normal function.
+
+ If the program has been interrupted while THIS_FRAME is current,
+ then clearly the resume address is inside the associated
+ function. There are three kinds of interruption: debugger stop
+ (next frame will be SENTINEL_FRAME), operating system
+ signal or exception (next frame will be SIGTRAMP_FRAME),
+ or debugger-induced function call (next frame will be
+ DUMMY_FRAME). So we only need to adjust the PC if
+ NEXT_FRAME is a normal function.
+
+ We check the type of NEXT_FRAME first, since it is already
+ known; frame type is determined by the unwinder, and since
+ we have THIS_FRAME we've already selected an unwinder for
+ NEXT_FRAME. */
+ if (get_frame_type (next_frame) == NORMAL_FRAME
+ && get_frame_type (this_frame) == NORMAL_FRAME)
+ return pc - 1;
-CORE_ADDR
-get_frame_address_in_block (struct frame_info *this_frame)
-{
- return frame_unwind_address_in_block (this_frame->next);
+ return pc;
}
static int
if (get_frame_type (fi) != NORMAL_FRAME)
return 0;
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (fi);
/* Sneaky: If the low-level unwind and high-level base code share a
common unwinder, let them share the prologue cache. */
if (fi->base->unwind == fi->unwind)
- return fi->base->this_base (fi->next, &fi->prologue_cache);
- return fi->base->this_base (fi->next, &fi->base_cache);
+ return fi->base->this_base (fi, &fi->prologue_cache);
+ return fi->base->this_base (fi, &fi->base_cache);
}
CORE_ADDR
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (fi);
/* Sneaky: If the low-level unwind and high-level base code share a
common unwinder, let them share the prologue cache. */
if (fi->base->unwind == fi->unwind)
- cache = &fi->prologue_cache;
- else
- cache = &fi->base_cache;
- return fi->base->this_locals (fi->next, cache);
+ return fi->base->this_locals (fi, &fi->prologue_cache);
+ return fi->base->this_locals (fi, &fi->base_cache);
}
CORE_ADDR
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (fi);
/* Sneaky: If the low-level unwind and high-level base code share a
common unwinder, let them share the prologue cache. */
if (fi->base->unwind == fi->unwind)
- cache = &fi->prologue_cache;
- else
- cache = &fi->base_cache;
- return fi->base->this_args (fi->next, cache);
+ return fi->base->this_args (fi, &fi->prologue_cache);
+ return fi->base->this_args (fi, &fi->base_cache);
}
/* Level of the selected frame: 0 for innermost, 1 for its caller, ...
if (frame->unwind == NULL)
/* Initialize the frame's unwinder because that's what
provides the frame's type. */
- frame->unwind = frame_unwind_find_by_frame (frame->next,
- &frame->prologue_cache);
+ frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache);
return frame->unwind->type;
}
safe_frame_unwind_memory (struct frame_info *this_frame,
CORE_ADDR addr, gdb_byte *buf, int len)
{
- /* NOTE: read_memory_nobpt returns zero on success! */
- return !read_memory_nobpt (addr, buf, len);
+ /* NOTE: target_read_memory returns zero on success! */
+ return !target_read_memory (addr, buf, len);
}
/* Architecture method. */
CORE_ADDR
get_frame_sp (struct frame_info *this_frame)
{
- return frame_sp_unwind (this_frame->next);
-}
-
-CORE_ADDR
-frame_sp_unwind (struct frame_info *next_frame)
-{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
/* Normality - an architecture that provides a way of obtaining any
frame inner-most address. */
- if (gdbarch_unwind_sp_p (current_gdbarch))
- return gdbarch_unwind_sp (current_gdbarch, next_frame);
- /* Things are looking grim. If it's the inner-most frame and there
- is a TARGET_READ_SP, then that can be used. */
- if (next_frame->level < 0 && TARGET_READ_SP_P ())
- return TARGET_READ_SP ();
+ if (gdbarch_unwind_sp_p (gdbarch))
+ /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to
+ operate on THIS_FRAME now. */
+ return gdbarch_unwind_sp (gdbarch, this_frame->next);
/* Now things are really are grim. Hope that the value returned by
- the SP_REGNUM register is meaningful. */
- if (SP_REGNUM >= 0)
- {
- ULONGEST sp;
- frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp);
- return sp;
- }
+ the gdbarch_sp_regnum register is meaningful. */
+ if (gdbarch_sp_regnum (gdbarch) >= 0)
+ return get_frame_register_unsigned (this_frame,
+ gdbarch_sp_regnum (gdbarch));
internal_error (__FILE__, __LINE__, _("Missing unwind SP method"));
}
}
}
+/* Clean up after a failed (wrong unwinder) attempt to unwind past
+ FRAME. */
+
+static void
+frame_cleanup_after_sniffer (void *arg)
+{
+ struct frame_info *frame = arg;
+
+ /* The sniffer should not allocate a prologue cache if it did not
+ match this frame. */
+ gdb_assert (frame->prologue_cache == NULL);
+
+ /* No sniffer should extend the frame chain; sniff based on what is
+ already certain. */
+ gdb_assert (!frame->prev_p);
+
+ /* The sniffer should not check the frame's ID; that's circular. */
+ gdb_assert (!frame->this_id.p);
+
+ /* Clear cached fields dependent on the unwinder.
+
+ The previous PC is independent of the unwinder, but the previous
+ function is not (see get_frame_address_in_block). */
+ frame->prev_func.p = 0;
+ frame->prev_func.addr = 0;
+
+ /* Discard the unwinder last, so that we can easily find it if an assertion
+ in this function triggers. */
+ frame->unwind = NULL;
+}
+
+/* Set FRAME's unwinder temporarily, so that we can call a sniffer.
+ Return a cleanup which should be called if unwinding fails, and
+ discarded if it succeeds. */
+
+struct cleanup *
+frame_prepare_for_sniffer (struct frame_info *frame,
+ const struct frame_unwind *unwind)
+{
+ gdb_assert (frame->unwind == NULL);
+ frame->unwind = unwind;
+ return make_cleanup (frame_cleanup_after_sniffer, frame);
+}
+
extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
static struct cmd_list_element *set_backtrace_cmdlist;
projects / binutils-gdb.git / blobdiff