/* 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. Assuming that NEXT is the immediate
+ inner frame to THIS and that NEXT and THIS are both NORMAL frames:
+
+ * 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 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.
+
+ The sanity checks above cannot be performed when a SIGTRAMP frame
+ is involved, because signal handlers might be executed on a different
+ stack than the stack used by the routine that caused the signal
+ to be raised. This can happen for instance when a thread exceeds
+ its maximum stack size. In this case, certain compilers implement
+ a stack overflow strategy that cause the handler to be run on a
+ different stack. */
+
+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 = gdbarch_inner_than (current_gdbarch, 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, enum frame_type this_type)
+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, this_type);
- 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, get_frame_type (fi));
+ 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);
struct regcache *scratch;
struct cleanup *cleanups;
+ if (get_frame_type (this_frame) == DUMMY_FRAME)
+ {
+ /* Popping a dummy frame involves restoring more than just registers.
+ dummy_frame_pop does all the work. */
+ dummy_frame_pop (get_frame_id (this_frame));
+ return;
+ }
+
/* Ensure that we have a frame to pop to. */
prev_frame = get_prev_frame_1 (this_frame);
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)
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)
{
}
}
-/* 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 (ptid_equal (inferior_ptid, null_ptid))
+ error (_("No selected thread."));
+ if (is_exited (inferior_ptid))
+ error (_("Invalid selected thread."));
+ if (is_executing (inferior_ptid))
+ error (_("Target is executing."));
+
if (current_frame == NULL)
{
struct frame_info *sentinel_frame =
static struct frame_info *selected_frame;
+int
+has_stack_frames (void)
+{
+ if (!target_has_registers || !target_has_stack || !target_has_memory)
+ return 0;
+
+ /* No current inferior, no frame. */
+ if (ptid_equal (inferior_ptid, null_ptid))
+ return 0;
+
+ /* Don't try to read from a dead thread. */
+ if (is_exited (inferior_ptid))
+ return 0;
+
+ /* ... or from a spinning thread. */
+ 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
thrown. */
{
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,
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);
}
fi->next = create_sentinel_frame (get_current_regcache ());
+ /* Set/update this frame's cached PC value, found in the next frame.
+ Do this before looking for this frame's unwinder. A sniffer is
+ very likely to read this, and the corresponding unwinder is
+ entitled to rely that the PC doesn't magically change. */
+ fi->next->prev_pc.value = pc;
+ fi->next->prev_pc.p = 1;
+
/* 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);
- deprecated_update_frame_pc_hack (fi, pc);
+ fi->this_id.value = frame_id_build (addr, pc);
if (frame_debug)
{
/* Observer for the target_changed event. */
-void
+static void
frame_observer_target_changed (struct target_ops *target)
{
reinit_frame_cache ();
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, "{ reinit_frame_cache () }\n");
}
{
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 this frame and the next frame are NORMAL.
+ See the comment at frame_id_inner for details. */
+ if (get_frame_type (this_frame) == NORMAL_FRAME
+ && 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)
{
method set the same lval and location information as
frame_register_unwind. */
if (this_frame->level > 0
- && gdbarch_pc_regnum (current_gdbarch) >= 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,
- gdbarch_pc_regnum (current_gdbarch),
+ gdbarch_pc_regnum (gdbarch),
&optimized, &lval, &addr, &realnum);
frame_register_unwind_location (get_next_frame (this_frame),
- gdbarch_pc_regnum (current_gdbarch),
- &optimized, &nlval, &naddr, &realnum);
+ 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);
{
struct frame_info *prev_frame;
- /* Return the inner-most frame, when the caller passes in NULL. */
- /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
- caller should have previously obtained a valid frame using
- get_selected_frame() and then called this code - only possibility
- I can think of is code behaving badly.
-
- NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
- block_innermost_frame(). It does the sequence: frame = NULL;
- while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
- it couldn't be written better, I don't know.
-
- NOTE: cagney/2003-01-11: I suspect what is happening in
- block_innermost_frame() is, when the target has no state
- (registers, memory, ...), it is still calling this function. The
- assumption being that this function will return NULL indicating
- that a frame isn't possible, rather than checking that the target
- has state and then calling get_current_frame() and
- get_prev_frame(). This is a guess mind. */
- if (this_frame == NULL)
- {
- /* NOTE: cagney/2002-11-09: There was a code segment here that
- would error out when CURRENT_FRAME was NULL. The comment
- that went with it made the claim ...
-
- ``This screws value_of_variable, which just wants a nice
- clean NULL return from block_innermost_frame if there are no
- frames. I don't think I've ever seen this message happen
- otherwise. And returning NULL here is a perfectly legitimate
- thing to do.''
-
- 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");
- return current_frame;
- }
-
/* There is always a frame. If this assertion fails, suspect that
something should be calling get_selected_frame() or
get_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 that falls within NEXT_FRAME's caller's code
- block, assuming that the caller is a THIS_TYPE frame. */
+/* Return an address that falls within THIS_FRAME's code block. */
CORE_ADDR
-frame_unwind_address_in_block (struct frame_info *next_frame,
- enum frame_type this_type)
+get_frame_address_in_block (struct frame_info *this_frame)
{
/* A draft address. */
- CORE_ADDR pc = frame_pc_unwind (next_frame);
-
- /* If NEXT_FRAME was called by a signal frame or dummy frame, then
- we shold not adjust the unwound PC. These frames may not call
- their next frame in the normal way; the operating system or GDB
- may have pushed their resume address manually onto the stack, so
- it may be the very first instruction. Even if the resume address
- was not manually pushed, they expect to be returned to. */
- if (this_type != NORMAL_FRAME)
- return pc;
-
- /* 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,
- get_frame_type (this_frame));
+ 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;
}
-void
-deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc)
-{
- if (frame_debug)
- fprintf_unfiltered (gdb_stdlog,
- "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
- frame->level, paddr_nz (pc));
- /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
- maintaining a locally allocated frame object. Since such frames
- are not in the frame chain, it isn't possible to assume that the
- frame has a next. Sigh. */
- if (frame->next != NULL)
- {
- /* While we're at it, update this frame's cached PC value, found
- in the next frame. Oh for the day when "struct frame_info"
- is opaque and this hack on hack can just go away. */
- frame->next->prev_pc.value = pc;
- frame->next->prev_pc.p = 1;
- }
-}
-
-void
-deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
-{
- if (frame_debug)
- fprintf_unfiltered (gdb_stdlog,
- "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
- frame->level, paddr_nz (base));
- /* See comment in "frame.h". */
- frame->this_id.value.stack_addr = base;
-}
-
/* Memory access methods. */
void
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. */
struct gdbarch *
get_frame_arch (struct frame_info *this_frame)
{
+ /* In the future, this function will return a per-frame
+ architecture instead of current_gdbarch. Calling the
+ routine with a NULL value of this_frame is a bug! */
+ gdb_assert (this_frame);
+
return current_gdbarch;
}
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);
+ 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 gdbarch_sp_regnum register is meaningful. */
- if (gdbarch_sp_regnum (current_gdbarch) >= 0)
- {
- ULONGEST sp;
- frame_unwind_unsigned_register (next_frame,
- gdbarch_sp_regnum (current_gdbarch), &sp);
- return sp;
- }
+ 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;