/* Cache and manage frames for GDB, the GNU debugger.
Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000,
- 2001, 2002, 2003 Free Software Foundation, Inc.
+ 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GDB.
#include "frame-base.h"
#include "command.h"
#include "gdbcmd.h"
+#include "observer.h"
+
+static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
/* We keep a cache of stack frames, each of which is a "struct
frame_info". The innermost one gets allocated (in
increases. This is a cached value. It could just as easily be
computed by counting back from the selected frame to the inner
most frame. */
- /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
+ /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
reserved to indicate a bogus frame - one that has been created
just to keep GDB happy (GDB always needs a frame). For the
moment leave this as speculation. */
int level;
/* The frame's type. */
- /* FIXME: cagney/2003-04-02: Should instead be returning
- ->unwind->type. Unfortunately, legacy code is still explicitly
- setting the type using the method deprecated_set_frame_type.
- Eliminate that method and this field can be eliminated. */
+ /* FIXME: cagney/2004-05-01: Should instead just use ->unwind->type.
+ Unfortunately, legacy_get_prev_frame is still explicitly setting
+ the type. Eliminate that method and this field can be
+ eliminated. */
enum frame_type type;
/* For each register, address of where it was saved on entry to the
/* The frame's low-level unwinder and corresponding cache. The
low-level unwinder is responsible for unwinding register values
for the previous frame. The low-level unwind methods are
- selected based on the presence, or otherwize, of register unwind
+ selected based on the presence, or otherwise, of register unwind
information such as CFI. */
void *prologue_cache;
const struct frame_unwind *unwind;
/* Find the unwinder. */
if (fi->unwind == NULL)
{
- fi->unwind = frame_unwind_find_by_frame (fi->next);
- /* FIXME: cagney/2003-04-02: Rather than storing the frame's
- type in the frame, the unwinder's type should be returned
- directly. Unfortunately, legacy code, called by
- legacy_get_prev_frame, explicitly set the frames type
- using the method deprecated_set_frame_type(). */
- gdb_assert (fi->unwind->type != UNKNOWN_FRAME);
+ fi->unwind = frame_unwind_find_by_frame (fi->next,
+ &fi->prologue_cache);
+ /* FIXME: cagney/2004-05-01: Should instead just use
+ ->unwind->type. Unfortunately, legacy_get_prev_frame is
+ still explicitly setting the type. Eliminate that method
+ and this field can be eliminated. */
fi->type = fi->unwind->type;
}
/* Find THIS frame's ID. */
return fi->this_id.value;
}
+struct frame_id
+frame_unwind_id (struct frame_info *next_frame)
+{
+ /* Use prev_frame, and not get_prev_frame. The latter will truncate
+ the frame chain, leading to this function unintentionally
+ returning a null_frame_id (e.g., when a caller requests the frame
+ ID of "main()"s caller. */
+ return get_frame_id (get_prev_frame_1 (next_frame));
+}
+
const struct frame_id null_frame_id; /* All zeros. */
struct frame_id
if (frame_id_inner (id, this))
/* Gone to far. */
return NULL;
- /* Either, we're not yet gone far enough out along the frame
- chain (inner(this,id), or we're comparing frameless functions
+ /* 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. */
}
}
else if (this_frame->level < 0)
{
- /* FIXME: cagney/2003-03-06: Old code and and a sentinel
+ /* FIXME: cagney/2003-03-06: Old code and a sentinel
frame. Do like was always done. Fetch the PC's value
- direct from the global registers array (via read_pc).
+ directly from the global registers array (via read_pc).
This assumes that this frame belongs to the current
global register cache. The assumption is dangerous. */
pc = read_pc ();
{
/* 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 betweening trying to extract the old values from the
- current_regcache while, at the same time writing new values
+ race between 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 = regcache_xmalloc (current_gdbarch);
struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch);
if (frame_debug)
{
- fprintf_unfiltered (gdb_stdlog,
- "{ frame_register_unwind (frame=%d,regnum=\"%s\",...) ",
- frame->level, frame_map_regnum_to_name (frame, regnum));
+ fprintf_unfiltered (gdb_stdlog, "\
+{ frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
+ frame->level, regnum,
+ frame_map_regnum_to_name (frame, regnum));
}
/* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
/* 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, there is some pretty busted code as it should have
+ isn't a frame, there is some pretty busted code as it should have
detected the problem before calling here. */
gdb_assert (frame != NULL);
/* Find the unwinder. */
if (frame->unwind == NULL)
{
- frame->unwind = frame_unwind_find_by_frame (frame->next);
- /* FIXME: cagney/2003-04-02: Rather than storing the frame's
- type in the frame, the unwinder's type should be returned
- directly. Unfortunately, legacy code, called by
- legacy_get_prev_frame, explicitly set the frames type using
- the method deprecated_set_frame_type(). */
- gdb_assert (frame->unwind->type != UNKNOWN_FRAME);
+ frame->unwind = frame_unwind_find_by_frame (frame->next,
+ &frame->prologue_cache);
+ /* FIXME: cagney/2004-05-01: Should instead just use ->unwind->type.
+ Unfortunately, legacy_get_prev_frame is still explicitly setting
+ the type. Eliminate that method and this field can be
+ eliminated. */
frame->type = frame->unwind->type;
}
/* Ask this frame to unwind its register. See comment in
- "frame-unwind.h" for why NEXT frame and this unwind cace are
+ "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);
return frame_unwind_register_unsigned (frame->next, regnum);
}
-void
-frame_unwind_signed_register (struct frame_info *frame, int regnum,
- LONGEST *val)
-{
- char buf[MAX_REGISTER_SIZE];
- frame_unwind_register (frame, regnum, buf);
- (*val) = extract_signed_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum));
-}
-
void
frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
ULONGEST *val)
int realnum;
frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
- /* FIXME: cagney/2002-05-15: This test, is just bogus.
+ /* 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
create_sentinel_frame (struct regcache *regcache)
{
struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
- frame->type = NORMAL_FRAME;
+ frame->type = SENTINEL_FRAME;
frame->level = -1;
/* Explicitly initialize the sentinel frame's cache. Provide it
with the underlying regcache. In the future additional
unwind_to_current_frame (struct ui_out *ui_out, void *args)
{
struct frame_info *frame = get_prev_frame (args);
- /* A sentinel frame can fail to unwind, eg, because it's PC value
+ /* A sentinel frame can fail to unwind, e.g., because its PC value
lands in somewhere like start. */
if (frame == NULL)
return 1;
struct frame_info *deprecated_selected_frame;
-/* Return the selected frame. Always non-null (unless there isn't an
+/* 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. */
return deprecated_selected_frame;
}
-/* This is a variant of get_selected_frame which can be called when
+/* This is a variant of get_selected_frame() which can be called when
the inferior does not have a frame; in that case it will return
- NULL instead of calling error (). */
+ NULL instead of calling error(). */
struct frame_info *
deprecated_safe_get_selected_frame (void)
struct symtab *s;
deprecated_selected_frame = fi;
- /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
+ /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
frame is being invalidated. */
- if (selected_frame_level_changed_hook)
- selected_frame_level_changed_hook (frame_relative_level (fi));
+ if (deprecated_selected_frame_level_changed_hook)
+ deprecated_selected_frame_level_changed_hook (frame_relative_level (fi));
/* FIXME: kseitz/2002-08-28: It would be nice to call
- selected_frame_level_changed_event right here, but due to limitations
+ selected_frame_level_changed_event() right here, but due to limitations
in the current interfaces, we would end up flooding UIs with events
- because select_frame is used extensively internally.
+ because select_frame() is used extensively internally.
Once we have frame-parameterized frame (and frame-related) commands,
the event notification can be moved here, since this function will only
- be called when the users selected frame is being changed. */
+ be called when the user's selected frame is being changed. */
/* Ensure that symbols for this frame are read in. Also, determine the
source language of this frame, and switch to it if desired. */
if (fi)
{
- s = find_pc_symtab (get_frame_pc (fi));
+ /* We retrieve the frame's symtab by using the frame PC. However
+ we cannot use the frame PC as-is, because it usually points to
+ the instruction following the "call", which is sometimes the
+ first instruction of another function. So we rely on
+ get_frame_address_in_block() which provides us with a PC which
+ is guaranteed to be inside the frame's code block. */
+ s = find_pc_symtab (get_frame_address_in_block (fi));
if (s
&& s->language != current_language->la_language
&& s->language != language_unknown
if (deprecated_get_frame_saved_regs (frame) == NULL)
{
- /* If nothing's initialized the saved regs, do it now. */
+ /* If nothing has initialized the saved regs, do it now. */
gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
gdb_assert (deprecated_get_frame_saved_regs (frame) != NULL);
*addrp = 0;
*realnump = -1;
if (bufferp != NULL)
- /* NOTE: cagney/2003-05-09: In-lined store_address with
- it's body - store_unsigned_integer. */
+ /* NOTE: cagney/2003-05-09: In-lined store_address() with
+ it's body - store_unsigned_integer(). */
store_unsigned_integer (bufferp, DEPRECATED_REGISTER_RAW_SIZE (regnum),
deprecated_get_frame_saved_regs (frame)[regnum]);
}
void **this_prologue_cache,
struct frame_id *id)
{
- /* legacy_get_prev_frame() always sets ->this_id.p, hence this is
- never needed. */
- internal_error (__FILE__, __LINE__, "legacy_saved_regs_this_id() called");
+ /* A developer is trying to bring up a new architecture, help them
+ by providing a default unwinder that refuses to unwind anything
+ (the ID is always NULL). In the case of legacy code,
+ legacy_get_prev_frame() will have previously set ->this_id.p, so
+ this code won't be called. */
+ (*id) = null_frame_id;
}
const struct frame_unwind legacy_saved_regs_unwinder = {
- /* Not really. It gets overridden by legacy_get_prev_frame. */
+ /* Not really. It gets overridden by legacy_get_prev_frame(). */
UNKNOWN_FRAME,
legacy_saved_regs_this_id,
legacy_saved_regs_prev_register
};
const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder;
-
-/* Function: deprecated_generic_get_saved_register
- Find register number REGNUM relative to FRAME and put its (raw,
- target format) contents in *RAW_BUFFER.
-
- Set *OPTIMIZED if the variable was optimized out (and thus can't be
- fetched). Note that this is never set to anything other than zero
- in this implementation.
-
- Set *LVAL to lval_memory, lval_register, or not_lval, depending on
- whether the value was fetched from memory, from a register, or in a
- strange and non-modifiable way (e.g. a frame pointer which was
- calculated rather than fetched). We will use not_lval for values
- fetched from generic dummy frames.
-
- Set *ADDRP to the address, either in memory or as a
- DEPRECATED_REGISTER_BYTE offset into the registers array. If the
- value is stored in a dummy frame, set *ADDRP to zero.
-
- The argument RAW_BUFFER must point to aligned memory. */
-
-void
-deprecated_generic_get_saved_register (char *raw_buffer, int *optimized,
- CORE_ADDR *addrp,
- struct frame_info *frame, int regnum,
- enum lval_type *lval)
-{
- if (!target_has_registers)
- error ("No registers.");
-
- /* Normal systems don't optimize out things with register numbers. */
- if (optimized != NULL)
- *optimized = 0;
-
- if (addrp) /* default assumption: not found in memory */
- *addrp = 0;
-
- /* Note: since the current frame's registers could only have been
- saved by frames INTERIOR TO the current frame, we skip examining
- the current frame itself: otherwise, we would be getting the
- previous frame's registers which were saved by the current frame. */
-
- if (frame != NULL)
- {
- for (frame = get_next_frame (frame);
- frame_relative_level (frame) >= 0;
- frame = get_next_frame (frame))
- {
- if (get_frame_type (frame) == DUMMY_FRAME)
- {
- if (lval) /* found it in a CALL_DUMMY frame */
- *lval = not_lval;
- if (raw_buffer)
- /* FIXME: cagney/2002-06-26: This should be via the
- gdbarch_register_read() method so that it, on the
- fly, constructs either a raw or pseudo register
- from the raw register cache. */
- regcache_raw_read
- (deprecated_find_dummy_frame_regcache (get_frame_pc (frame),
- get_frame_base (frame)),
- regnum, raw_buffer);
- return;
- }
-
- DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
- if (deprecated_get_frame_saved_regs (frame) != NULL
- && deprecated_get_frame_saved_regs (frame)[regnum] != 0)
- {
- if (lval) /* found it saved on the stack */
- *lval = lval_memory;
- if (regnum == SP_REGNUM)
- {
- if (raw_buffer) /* SP register treated specially */
- /* NOTE: cagney/2003-05-09: In-line store_address
- with it's body - store_unsigned_integer. */
- store_unsigned_integer (raw_buffer,
- DEPRECATED_REGISTER_RAW_SIZE (regnum),
- deprecated_get_frame_saved_regs (frame)[regnum]);
- }
- else
- {
- if (addrp) /* any other register */
- *addrp = deprecated_get_frame_saved_regs (frame)[regnum];
- if (raw_buffer)
- read_memory (deprecated_get_frame_saved_regs (frame)[regnum], raw_buffer,
- DEPRECATED_REGISTER_RAW_SIZE (regnum));
- }
- return;
- }
- }
- }
-
- /* If we get thru the loop to this point, it means the register was
- not saved in any frame. Return the actual live-register value. */
-
- if (lval) /* found it in a live register */
- *lval = lval_register;
- if (addrp)
- *addrp = DEPRECATED_REGISTER_BYTE (regnum);
- if (raw_buffer)
- deprecated_read_register_gen (regnum, raw_buffer);
-}
-
/* Determine the frame's type based on its PC. */
static enum frame_type
frame_type_from_pc (CORE_ADDR pc)
{
- /* FIXME: cagney/2002-11-24: Can't yet directly call
- pc_in_dummy_frame() as some architectures don't set
- PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
- latter is implemented by simply calling pc_in_dummy_frame). */
if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
- && DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0))
+ && deprecated_pc_in_call_dummy (pc, 0, 0))
return DUMMY_FRAME;
else
- {
- char *name;
- find_pc_partial_function (pc, &name, NULL, NULL);
- if (PC_IN_SIGTRAMP (pc, name))
- return SIGTRAMP_FRAME;
- else
- return NORMAL_FRAME;
- }
+ return NORMAL_FRAME;
}
/* Create an arbitrary (i.e. address specified by user) or innermost frame.
/* 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->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
if (fi->unwind->type != UNKNOWN_FRAME)
fi->type = fi->unwind->type;
else
return NULL;
}
-struct frame_info *
-deprecated_get_next_frame_hack (struct frame_info *this_frame)
+/* Observer for the target_changed event. */
+
+void
+frame_observer_target_changed (struct target_ops *target)
{
- return this_frame->next;
+ flush_cached_frames ();
}
/* Flush the entire frame cache. */
}
/* Create the previous frame using the deprecated methods
- INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
+ INIT_EXTRA_INFO, and INIT_FRAME_PC. */
static struct frame_info *
legacy_get_prev_frame (struct frame_info *this_frame)
There is no reason to worry about memory leaks, should the
remainder of the function fail. The allocated memory will be
quickly reclaimed when the frame cache is flushed, and the `we've
- been here before' check, in get_prev_frame will stop repeated
+ been here before' check, in get_prev_frame() will stop repeated
memory allocation calls. */
prev = FRAME_OBSTACK_ZALLOC (struct frame_info);
prev->level = this_frame->level + 1;
- /* Do not completly wire it in to the frame chain. Some (bad) code
+ /* Do not completely wire it in to the frame chain. Some (bad) code
in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull
some fancy tricks (of course such code is, by definition,
recursive).
/* NOTE: cagney/2002-11-18: Should have been correctly setting the
frame's type here, before anything else, and not last, at the
bottom of this function. The various
- DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
- DEPRECATED_INIT_FRAME_PC_FIRST and
+ DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, and
DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
that handle the frame not being correctly set from the start.
Unfortunately those same work-arounds rely on the type defaulting
Note that the pc-unwind is intentionally performed before the
frame chain. This is ok since, for old targets, both
- frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
+ frame_pc_unwind() (nee, DEPRECATED_FRAME_SAVED_PC) and
DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
have already been initialized (using
DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
/* Set the unwind functions based on that identified PC. Ditto
for the "type" but strongly prefer the unwinder's frame type. */
- prev->unwind = frame_unwind_find_by_frame (prev->next);
+ prev->unwind = frame_unwind_find_by_frame (prev->next,
+ &prev->prologue_cache);
if (prev->unwind->type == UNKNOWN_FRAME)
prev->type = frame_type_from_pc (get_frame_pc (prev));
else
frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
function invocation. */
if (this_frame->level == 0)
- /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
+ /* FIXME: 2002-11-09: Frameless functions can occur anywhere in
the frame chain, not just the inner most frame! The generic,
per-architecture, frame code should handle this and the below
should simply be removed. */
- fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame);
+ fromleaf = (DEPRECATED_FRAMELESS_FUNCTION_INVOCATION_P ()
+ && DEPRECATED_FRAMELESS_FUNCTION_INVOCATION (this_frame));
else
fromleaf = 0;
architecture frame-pointer register!) of the caller is the same
as the callee. */
/* FIXME: 2002-11-09: There isn't any reason to special case this
- edge condition. Instead the per-architecture code should hande
+ edge condition. Instead the per-architecture code should handle
it locally. */
/* FIXME: cagney/2003-06-16: This returns the inner most stack
address for the previous frame, that, however, is wrong. It
to the new frame code. Implement FRAME_CHAIN the way the
new frame will. */
/* Find PREV frame's unwinder. */
- prev->unwind = frame_unwind_find_by_frame (this_frame->next);
- /* FIXME: cagney/2003-04-02: Rather than storing the frame's
- type in the frame, the unwinder's type should be returned
- directly. Unfortunately, legacy code, called by
- legacy_get_prev_frame, explicitly set the frames type
- using the method deprecated_set_frame_type(). */
+ prev->unwind = frame_unwind_find_by_frame (this_frame,
+ &prev->prologue_cache);
+ /* FIXME: cagney/2004-05-01: Should instead just use
+ ->unwind->type. Unfortunately, legacy_get_prev_frame is
+ still explicitly setting the type. Eliminate that method
+ and this field can be eliminated. */
prev->type = prev->unwind->type;
/* Find PREV frame's ID. */
prev->unwind->this_id (this_frame,
machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
- We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
- complication to an already overcomplicated part of GDB.
- gnu@cygnus.com, 15Sep92.
-
Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
reason for things to be this complicated.
The trick is to assume that there is always a frame. Instead of
- special casing the inner-most frame, create fake frame
+ special casing the inner-most frame, create a fake frame
(containing the hardware registers) that is inner to the
user-visible inner-most frame (...) and then unwind from that.
- That way architecture code can use use the standard
+ That way architecture code can use the standard
frame_XX_unwind() functions and not differentiate between the
inner most and any other case.
FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
without first needing the frame! Instead of the convolution
below, we could have simply called FRAME_SAVED_PC() and been done
- with it! Note that FRAME_SAVED_PC() is being superseed by
+ with it! Note that FRAME_SAVED_PC() is being superseded by
frame_pc_unwind() and that function does have somewhere to cache
that PC value. */
- if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
- deprecated_update_frame_pc_hack (prev,
- DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf,
- prev));
-
if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev);
/* This entry is in the frame queue now, which is good since
FRAME_SAVED_PC may use that queue to figure out its value (see
- tm-sparc.h). We want the pc saved in the inferior frame. */
+ tm-sparc.h). We want the PC saved in the inferior frame. */
if (DEPRECATED_INIT_FRAME_PC_P ())
deprecated_update_frame_pc_hack (prev,
DEPRECATED_INIT_FRAME_PC (fromleaf,
If there isn't a FRAME_CHAIN, the code above will have already
done this. */
if (prev->unwind == NULL)
- prev->unwind = frame_unwind_find_by_frame (prev->next);
+ prev->unwind = frame_unwind_find_by_frame (prev->next,
+ &prev->prologue_cache);
- /* If the unwinder provides a frame type, use it. Otherwize
+ /* If the unwinder provides a frame type, use it. Otherwise
continue on to that heuristic mess. */
if (prev->unwind->type != UNKNOWN_FRAME)
{
}
/* NOTE: cagney/2002-11-18: The code segments, found in
- create_new_frame and get_prev_frame(), that initializes the
- frames type is subtly different. The latter only updates ->type
+ create_new_frame() and get_prev_frame(), that initialize the
+ frame's type is subtly different. The latter only updates ->type
when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
get_prev_frame() overriding the frame's type when the INIT code
has previously set it. This is really somewhat bogus. The
initialization, as seen in create_new_frame(), should occur
before the INIT function has been called. */
if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
- && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
- ? DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (prev), 0, 0)
- : pc_in_dummy_frame (get_frame_pc (prev))))
+ && deprecated_pc_in_call_dummy (get_frame_pc (prev), 0, 0))
prev->type = DUMMY_FRAME;
- else
- {
- /* FIXME: cagney/2002-11-10: This should be moved to before the
- INIT code above so that the INIT code knows what the frame's
- type is (in fact, for a [generic] dummy-frame, the type can
- be set and then the entire initialization can be skipped.
- Unforunatly, its the INIT code that sets the PC (Hmm, catch
- 22). */
- char *name;
- find_pc_partial_function (get_frame_pc (prev), &name, NULL, NULL);
- if (PC_IN_SIGTRAMP (get_frame_pc (prev), name))
- prev->type = SIGTRAMP_FRAME;
- /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
- architectures are forcing the frame's type in INIT so we
- don't want to override it here. Remember, NORMAL_FRAME == 0,
- so it all works (just :-/). Once this initialization is
- moved to the start of this function, all this nastness will
- go away. */
- }
if (prev->type == NORMAL_FRAME)
prev->this_id.value.code_addr
return prev;
}
-/* Return a structure containing various interesting information
- about the frame that called THIS_FRAME. Returns NULL
- if there is no such frame. */
+/* Return a "struct frame_info" corresponding to the frame that called
+ THIS_FRAME. Returns NULL if there is no such frame.
-struct frame_info *
-get_prev_frame (struct frame_info *this_frame)
+ Unlike get_prev_frame, this function always tries to unwind the
+ frame. */
+
+static struct frame_info *
+get_prev_frame_1 (struct frame_info *this_frame)
{
struct frame_info *prev_frame;
+ gdb_assert (this_frame != NULL);
+
if (frame_debug)
{
- fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
+ fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_1 (this_frame=");
if (this_frame != NULL)
fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
else
fprintf_unfiltered (gdb_stdlog, ") ");
}
- /* 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 is
- block_innermost_frame() is, when the target has no state
- (registers, memory, ...), 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. */
- 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(). */
- gdb_assert (this_frame != NULL);
-
- /* Make sure we pass an address within THIS_FRAME's code block to
- inside_main_func. Otherwise, we might stop unwinding at a
- function which has a call instruction as its last instruction if
- that function immediately precedes main(). */
- if (this_frame->level >= 0
- && !backtrace_past_main
- && inside_main_func (get_frame_address_in_block (this_frame)))
- /* Don't unwind past main(), bug always unwind the sentinel frame.
- Note, this is done _before_ the frame has been marked as
- previously unwound. That way if the user later decides to
- allow unwinds past main(), that just happens. */
- {
- if (frame_debug)
- fprintf_unfiltered (gdb_stdlog, "-> NULL // inside main func }\n");
- return NULL;
- }
-
- if (this_frame->level > backtrace_limit)
- {
- error ("Backtrace limit of %d exceeded", backtrace_limit);
- }
-
- /* If we're already inside the entry function for the main objfile,
- then it isn't valid. Don't apply this test to a dummy frame -
- dummy frame PC's typically land in the entry func. Don't apply
- this test to the sentinel frame. Sentinel frames should always
- be allowed to unwind. */
- /* NOTE: cagney/2003-02-25: Don't enable until someone has found
- hard evidence that this is needed. */
- /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func - wasn't
- checking for "main" in the minimal symbols. With that fixed
- asm-source tests now stop in "main" instead of halting the
- backtrace in wierd and wonderful ways somewhere inside the entry
- file. Suspect that deprecated_inside_entry_file and
- inside_entry_func tests were added to work around that (now
- fixed) case. */
- /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
- suggested having the inside_entry_func test use the
- inside_main_func msymbol trick (along with entry_point_address I
- guess) to determine the address range of the start function.
- That should provide a far better stopper than the current
- heuristics. */
- /* NOTE: cagney/2003-07-15: Need to add a "set backtrace
- beyond-entry-func" command so that this can be selectively
- disabled. */
- if (0
-#if 0
- && backtrace_beyond_entry_func
-#endif
- && this_frame->type != DUMMY_FRAME && this_frame->level >= 0
- && inside_entry_func (get_frame_pc (this_frame)))
- {
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, "// inside entry func }\n");
- }
- return NULL;
- }
-
/* Only try to do the unwind once. */
if (this_frame->prev_p)
{
}
this_frame->prev_p = 1;
- /* If we're inside the entry file, it isn't valid. Don't apply this
- test to a dummy frame - dummy frame PC's typically land in the
- entry file. Don't apply this test to the sentinel frame.
- Sentinel frames should always be allowed to unwind. */
- /* NOTE: drow/2002-12-25: should there be a way to disable this
- check? It assumes a single small entry file, and the way some
- debug readers (e.g. dbxread) figure out which object is the
- entry file is somewhat hokey. */
- /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
- then it should probably be moved to before the ->prev_p test,
- above. */
- /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call
- to deprecated_inside_entry_file destroys a meaningful backtrace
- under some conditions. E. g. the backtrace tests in the
- asm-source testcase are broken for some targets. In this test
- the functions are all implemented as part of one file and the
- testcase is not necessarily linked with a start file (depending
- on the target). What happens is, that the first frame is printed
- normaly and following frames are treated as being inside the
- enttry file then. This way, only the #0 frame is printed in the
- backtrace output. */
- if (0
- && this_frame->type != DUMMY_FRAME && this_frame->level >= 0
- && deprecated_inside_entry_file (get_frame_pc (this_frame)))
- {
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, " // inside entry file }\n");
- }
- return NULL;
- }
-
/* If any of the old frame initialization methods are around, use
- the legacy get_prev_frame method. */
+ the legacy get_prev_frame() method. */
if (legacy_frame_p (current_gdbarch))
{
prev_frame = legacy_get_prev_frame (this_frame);
/* Check that this frame's ID isn't inner to (younger, below, next)
the next frame. This happens when a frame unwind goes backwards.
- Since the sentinel frame doesn't really exist, don't compare the
- inner-most against that sentinel. */
- if (this_frame->level > 0
+ 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->type != SIGTRAMP_FRAME
&& frame_id_inner (get_frame_id (this_frame),
get_frame_id (this_frame->next)))
error ("Previous frame inner to this frame (corrupt stack?)");
prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
prev_frame->level = this_frame->level + 1;
- /* Try to unwind the PC. If that doesn't work, assume we've reached
- the oldest frame and simply return. Is there a better sentinal
- value? The unwound PC value is then used to initialize the new
- previous frame's type.
-
- Note that the pc-unwind is intentionally performed before the
- frame chain. This is ok since, for old targets, both
- frame_pc_unwind (nee, FRAME_SAVED_PC) and
- DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
- have already been initialized (using
- DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
- doesn't matter.
-
- By unwinding the PC first, it becomes possible to, in the case of
- a dummy frame, avoid also unwinding the frame ID. This is
- because (well ignoring the PPC) a dummy frame can be located
- using THIS_FRAME's frame ID. */
-
- if (frame_pc_unwind (this_frame) == 0)
- {
- /* The allocated PREV_FRAME will be reclaimed when the frame
- obstack is next purged. */
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, " // unwound PC zero }\n");
- }
- return NULL;
- }
-
/* Don't yet compute ->unwind (and hence ->type). It is computed
on-demand in get_frame_type, frame_register_unwind, and
get_frame_id. */
return prev_frame;
}
+/* 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,
+ const char *reason)
+{
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
+ if (this_frame != NULL)
+ fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
+ else
+ fprintf_unfiltered (gdb_stdlog, "<NULL>");
+ fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason);
+ }
+}
+
+/* Return a structure containing various interesting information about
+ the frame that called THIS_FRAME. Returns NULL if there is entier
+ no such frame or the frame fails any of a set of target-independent
+ condition that should terminate the frame chain (e.g., as unwinding
+ past main()).
+
+ This function should not contain target-dependent tests, such as
+ checking whether the program-counter is zero. */
+
+struct frame_info *
+get_prev_frame (struct frame_info *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(). */
+ gdb_assert (this_frame != NULL);
+
+ /* Make sure we pass an address within THIS_FRAME's code block to
+ inside_main_func(). Otherwise, we might stop unwinding at a
+ function which has a call instruction as its last instruction if
+ that function immediately precedes main(). */
+ if (this_frame->level >= 0
+ && !backtrace_past_main
+ && inside_main_func (get_frame_address_in_block (this_frame)))
+ /* Don't unwind past main(), but always unwind the sentinel frame.
+ Note, this is done _before_ the frame has been marked as
+ previously unwound. That way if the user later decides to
+ allow unwinds past main(), that just happens. */
+ {
+ frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside main func");
+ return NULL;
+ }
+
+ if (this_frame->level > backtrace_limit)
+ {
+ error ("Backtrace limit of %d exceeded", backtrace_limit);
+ }
+
+ /* If we're already inside the entry function for the main objfile,
+ then it isn't valid. Don't apply this test to a dummy frame -
+ dummy frame PCs typically land in the entry func. Don't apply
+ this test to the sentinel frame. Sentinel frames should always
+ be allowed to unwind. */
+ /* NOTE: cagney/2003-02-25: Don't enable until someone has found
+ hard evidence that this is needed. */
+ /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
+ wasn't checking for "main" in the minimal symbols. With that
+ fixed asm-source tests now stop in "main" instead of halting the
+ backtrace in weird and wonderful ways somewhere inside the entry
+ file. Suspect that tests for inside the entry file/func were
+ added to work around that (now fixed) case. */
+ /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
+ suggested having the inside_entry_func test use the
+ inside_main_func() msymbol trick (along with entry_point_address()
+ I guess) to determine the address range of the start function.
+ That should provide a far better stopper than the current
+ heuristics. */
+ /* NOTE: cagney/2003-07-15: Need to add a "set backtrace
+ beyond-entry-func" command so that this can be selectively
+ disabled. */
+ if (0
+#if 0
+ && backtrace_beyond_entry_func
+#endif
+ && this_frame->type != DUMMY_FRAME && this_frame->level >= 0
+ && inside_entry_func (this_frame))
+ {
+ frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
+ return NULL;
+ }
+
+ return get_prev_frame_1 (this_frame);
+}
+
CORE_ADDR
get_frame_pc (struct frame_info *frame)
{
"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. */
+ get_frame_type() for why ->type can't be used. */
if (next_frame->level >= 0
&& get_frame_type (next_frame) == NORMAL_FRAME)
--pc;
legacy code. It will be initialized in legacy_get_prev_frame(). */
if (frame->unwind == NULL && !legacy_frame_p (current_gdbarch))
{
- /* Initialize the frame's unwinder because it is that which
+ /* Initialize the frame's unwinder because that's what
provides the frame's type. */
- frame->unwind = frame_unwind_find_by_frame (frame->next);
- /* FIXME: cagney/2003-04-02: Rather than storing the frame's
- type in the frame, the unwinder's type should be returned
- directly. Unfortunately, legacy code, called by
- legacy_get_prev_frame, explicitly set the frames type using
- the method deprecated_set_frame_type(). */
- gdb_assert (frame->unwind->type != UNKNOWN_FRAME);
+ frame->unwind = frame_unwind_find_by_frame (frame->next,
+ &frame->prologue_cache);
+ /* FIXME: cagney/2004-05-01: Should instead just use
+ ->unwind->type. Unfortunately, legacy_get_prev_frame is
+ still explicitly setting the type. Eliminate that method and
+ this field can be eliminated. */
frame->type = frame->unwind->type;
}
if (frame->type == UNKNOWN_FRAME)
return frame->type;
}
-void
-deprecated_set_frame_type (struct frame_info *frame, enum frame_type type)
-{
- /* Arrrg! See comment in "frame.h". */
- frame->type = type;
-}
-
struct frame_extra_info *
get_frame_extra_info (struct frame_info *fi)
{
"{ 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 frame's
+ 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)
frame->this_id.value.stack_addr = base;
}
-void
-deprecated_set_frame_saved_regs_hack (struct frame_info *frame,
- CORE_ADDR *saved_regs)
-{
- frame->saved_regs = saved_regs;
-}
-
-void
-deprecated_set_frame_extra_info_hack (struct frame_info *frame,
- struct frame_extra_info *extra_info)
-{
- frame->extra_info = extra_info;
-}
-
struct frame_info *
-deprecated_frame_xmalloc (void)
+deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs,
+ long sizeof_extra_info)
{
struct frame_info *frame = XMALLOC (struct frame_info);
memset (frame, 0, sizeof (*frame));
frame->this_id.p = 1;
- return frame;
-}
-
-struct frame_info *
-deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs,
- long sizeof_extra_info)
-{
- struct frame_info *frame = deprecated_frame_xmalloc ();
make_cleanup (xfree, frame);
if (sizeof_saved_regs > 0)
{
return read_memory_unsigned_integer (addr, len);
}
+int
+safe_frame_unwind_memory (struct frame_info *this_frame,
+ CORE_ADDR addr, void *buf, int len)
+{
+ /* NOTE: read_memory_nobpt returns zero on success! */
+ return !read_memory_nobpt (addr, buf, len);
+}
+
/* Architecture method. */
struct gdbarch *
CORE_ADDR
frame_sp_unwind (struct frame_info *next_frame)
{
- /* Normality, an architecture that provides a way of obtaining any
+ /* 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. */
+ is a TARGET_READ_SP, then that can be used. */
if (next_frame->level < 0 && TARGET_READ_SP_P ())
return TARGET_READ_SP ();
/* Now things are really are grim. Hope that the value returned by
int
legacy_frame_p (struct gdbarch *current_gdbarch)
{
- return (DEPRECATED_INIT_FRAME_PC_P ()
- || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
- || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
- || DEPRECATED_FRAME_CHAIN_P ()
- || !gdbarch_unwind_dummy_id_p (current_gdbarch));
+ if (DEPRECATED_INIT_FRAME_PC_P ()
+ || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
+ || DEPRECATED_FRAME_CHAIN_P ())
+ /* No question, it's a legacy frame. */
+ return 1;
+ if (gdbarch_unwind_dummy_id_p (current_gdbarch))
+ /* No question, it's not a legacy frame (provided none of the
+ deprecated methods checked above are present that is). */
+ return 0;
+ if (DEPRECATED_TARGET_READ_FP_P ()
+ || DEPRECATED_FP_REGNUM >= 0)
+ /* Assume it's legacy. If you're trying to convert a legacy frame
+ target to the new mechanism, get rid of these. legacy
+ get_prev_frame() requires these when unwind_frame_id() isn't
+ available. */
+ return 1;
+ /* Default to assuming that it's brand new code, and hence not
+ legacy. Force it down the non-legacy path so that the new code
+ uses the new frame mechanism from day one. Dummy frames won't
+ work very well but we can live with that. */
+ return 0;
}
extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
{
obstack_init (&frame_cache_obstack);
+ observer_attach_target_changed (frame_observer_target_changed);
+
add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, "\
Set backtrace specific variables.\n\
Configure backtrace variables such as the backtrace limit",
projects / deliverable / binutils-gdb.git / blobdiff