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2004-07-31 Andrew Cagney <cagney@gnu.org>

Browse Source 
* frame.h (legacy_saved_regs_unwind)
	(legacy_frame_chain_valid, legacy_frame_p)
	(enum frame_type): Delete UNKNOWN_FRAME.
	* dummy-frame.c (dummy_frame_this_id):
	* frame-unwind.c (frame_unwind_find_by_frame):
	* frame.c (struct frame_info): Delete the field "type".
	(legacy_saved_regs_prev_register, legacy_get_prev_frame)
	(legacy_saved_regs_this_id, legacy_saved_regs_unwinder)
	(legacy_saved_regs_unwind, legacy_frame_p)
	(frame_type_from_pc): Delete.
	(get_frame_id, frame_pop, frame_register_unwind, get_prev_frame_1)
	(fprint_frame, create_new_frame, fprint_frame_type): Simplify.
This commit is contained in:
Andrew Cagney 2004-07-31 21:41:50 +00:00
parent 5a5effe17e
commit c1bf6f6527
5 changed files with 52 additions and 715 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
gdb/ChangeLog
View File

@ -1,3 +1,18 @@
2004-07-31 Andrew Cagney <cagney@gnu.org>
* frame.h (legacy_saved_regs_unwind)
(legacy_frame_chain_valid, legacy_frame_p)
(enum frame_type): Delete UNKNOWN_FRAME.
* dummy-frame.c (dummy_frame_this_id):
* frame-unwind.c (frame_unwind_find_by_frame):
* frame.c (struct frame_info): Delete the field "type".
(legacy_saved_regs_prev_register, legacy_get_prev_frame)
(legacy_saved_regs_this_id, legacy_saved_regs_unwinder)
(legacy_saved_regs_unwind, legacy_frame_p)
(frame_type_from_pc): Delete.
(get_frame_id, frame_pop, frame_register_unwind, get_prev_frame_1)
(fprint_frame, create_new_frame, fprint_frame_type): Simplify.
2004-07-31 Mark Kettenis <kettenis@gnu.org>
* sparc64obsd-tdep.c (sparc64obsd_pc_in_sigtramp): Fix

10
gdb/dummy-frame.c
View File

@ -358,16 +358,6 @@ dummy_frame_this_id (struct frame_info *next_frame,
can go away. */
(*this_id) = frame_id_build (deprecated_read_fp (), read_pc ());
}
else if (legacy_frame_p (current_gdbarch)
&& get_prev_frame (next_frame))
{
/* Things are looking seriously grim! Assume that the legacy
get_prev_frame code has already created THIS frame and linked
it in to the frame chain (a pretty bold assumption), extract
the ID from THIS base / pc. */
(*this_id) = frame_id_build (get_frame_base (get_prev_frame (next_frame)),
get_frame_pc (get_prev_frame (next_frame)));
}
else
{
/* Ouch! We're not trying to find the innermost frame's ID yet

2
gdb/frame-unwind.c
View File

@ -106,7 +106,7 @@ frame_unwind_find_by_frame (struct frame_info *next_frame, void **this_cache)
return entry->unwinder;
}
}
return legacy_saved_regs_unwind;
internal_error (__FILE__, __LINE__, "frame_unwind_find_by_frame failed");
}
extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */

718
gdb/frame.c
View File

@ -66,13 +66,6 @@ struct frame_info
moment leave this as speculation. */
int level;
/* The frame's type. */
/* 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
frame, or zero if it was not saved on entry to this frame. This
includes special registers such as pc and fp saved in special
@ -165,9 +158,6 @@ fprint_frame_type (struct ui_file *file, enum frame_type type)
{
switch (type)
{
case UNKNOWN_FRAME:
fprintf_unfiltered (file, "UNKNOWN_FRAME");
return;
case NORMAL_FRAME:
fprintf_unfiltered (file, "NORMAL_FRAME");
return;
@ -195,7 +185,10 @@ fprint_frame (struct ui_file *file, struct frame_info *fi)
fprintf_unfiltered (file, "level=%d", fi->level);
fprintf_unfiltered (file, ",");
fprintf_unfiltered (file, "type=");
fprint_frame_type (file, fi->type);
if (fi->unwind != NULL)
fprint_frame_type (file, fi->unwind->type);
else
fprintf_unfiltered (file, "<unknown>");
fprintf_unfiltered (file, ",");
fprintf_unfiltered (file, "unwind=");
if (fi->unwind != NULL)
@ -235,21 +228,13 @@ get_frame_id (struct frame_info *fi)
}
if (!fi->this_id.p)
{
gdb_assert (!legacy_frame_p (current_gdbarch));
if (frame_debug)
fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ",
fi->level);
/* Find the unwinder. */
if (fi->unwind == NULL)
{
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;
}
fi->unwind = frame_unwind_find_by_frame (fi->next,
&fi->prologue_cache);
/* Find THIS frame's ID. */
fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
fi->this_id.p = 1;
@ -504,39 +489,27 @@ do_frame_unwind_register (void *src, int regnum, void *buf)
void
frame_pop (struct frame_info *this_frame)
{
struct regcache *scratch_regcache;
struct cleanup *cleanups;
/* 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
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);
regcache_save (scratch, do_frame_unwind_register, 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
register transfer and that the sequence of register writes should
be batched. The pair target_prepare_to_store() and
target_store_registers() kind of suggest this functionality.
Unfortunately, they don't implement it. Their lack of a formal
definition can lead to targets writing back bogus values
(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);
do_cleanups (cleanups);
if (DEPRECATED_POP_FRAME_P ())
{
/* A legacy architecture that has implemented a custom pop
function. All new architectures should instead be using the
generic code below. */
DEPRECATED_POP_FRAME;
}
else
{
/* 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 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);
regcache_save (scratch, do_frame_unwind_register, 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 register transfer and that the sequence of register
writes should be batched. The pair target_prepare_to_store()
and target_store_registers() kind of suggest this
functionality. Unfortunately, they don't implement it. Their
lack of a formal definition can lead to targets writing back
bogus values (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);
do_cleanups (cleanups);
}
/* We've made right mess of GDB's local state, just discard
everything. */
flush_cached_frames ();
@ -573,15 +546,8 @@ frame_register_unwind (struct frame_info *frame, int regnum,
/* Find the unwinder. */
if (frame->unwind == NULL)
{
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;
}
frame->unwind = frame_unwind_find_by_frame (frame->next,
&frame->prologue_cache);
/* Ask this frame to unwind its register. See comment in
"frame-unwind.h" for why NEXT frame and this unwind cache are
@ -796,7 +762,6 @@ static struct frame_info *
create_sentinel_frame (struct regcache *regcache)
{
struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
frame->type = SENTINEL_FRAME;
frame->level = -1;
/* Explicitly initialize the sentinel frame's cache. Provide it
with the underlying regcache. In the future additional
@ -974,131 +939,7 @@ select_frame (struct frame_info *fi)
}
}
}
/* Return the register saved in the simplistic ``saved_regs'' cache.
If the value isn't here AND a value is needed, try the next inner
most frame. */
static void
legacy_saved_regs_prev_register (struct frame_info *next_frame,
void **this_prologue_cache,
int regnum, int *optimizedp,
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnump, void *bufferp)
{
/* HACK: New code is passed the next frame and this cache.
Unfortunately, old code expects this frame. Since this is a
backward compatibility hack, cheat by walking one level along the
prologue chain to the frame the old code expects.
Do not try this at home. Professional driver, closed course. */
struct frame_info *frame = next_frame->prev;
gdb_assert (frame != NULL);
if (deprecated_get_frame_saved_regs (frame) == NULL)
{
/* 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);
}
if (deprecated_get_frame_saved_regs (frame) != NULL
&& deprecated_get_frame_saved_regs (frame)[regnum] != 0)
{
if (regnum == SP_REGNUM)
{
/* SP register treated specially. */
*optimizedp = 0;
*lvalp = not_lval;
*addrp = 0;
*realnump = -1;
if (bufferp != NULL)
/* 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]);
}
else
{
/* Any other register is saved in memory, fetch it but cache
a local copy of its value. */
*optimizedp = 0;
*lvalp = lval_memory;
*addrp = deprecated_get_frame_saved_regs (frame)[regnum];
*realnump = -1;
if (bufferp != NULL)
{
#if 1
/* Save each register value, as it is read in, in a
frame based cache. */
void **regs = (*this_prologue_cache);
if (regs == NULL)
{
int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
* sizeof (void *));
regs = frame_obstack_zalloc (sizeof_cache);
(*this_prologue_cache) = regs;
}
if (regs[regnum] == NULL)
{
regs[regnum]
= frame_obstack_zalloc (DEPRECATED_REGISTER_RAW_SIZE (regnum));
read_memory (deprecated_get_frame_saved_regs (frame)[regnum], regs[regnum],
DEPRECATED_REGISTER_RAW_SIZE (regnum));
}
memcpy (bufferp, regs[regnum], DEPRECATED_REGISTER_RAW_SIZE (regnum));
#else
/* Read the value in from memory. */
read_memory (deprecated_get_frame_saved_regs (frame)[regnum], bufferp,
DEPRECATED_REGISTER_RAW_SIZE (regnum));
#endif
}
}
return;
}
/* No luck. Assume this and the next frame have the same register
value. Pass the unwind request down the frame chain to the next
frame. Hopefully that frame will find the register's location. */
frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp,
realnump, bufferp);
}
static void
legacy_saved_regs_this_id (struct frame_info *next_frame,
void **this_prologue_cache,
struct frame_id *id)
{
/* 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(). */
UNKNOWN_FRAME,
legacy_saved_regs_this_id,
legacy_saved_regs_prev_register
};
const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder;
/* Determine the frame's type based on its PC. */
static enum frame_type
frame_type_from_pc (CORE_ADDR pc)
{
/* NOTE: cagney/2004-05-08: Eliminating this function depends on all
architectures being forced to use the frame-unwind code. */
if (deprecated_pc_in_call_dummy (pc))
return DUMMY_FRAME;
else
return NORMAL_FRAME;
}
/* Create an arbitrary (i.e. address specified by user) or innermost frame.
Always returns a non-NULL value. */
@ -1121,10 +962,6 @@ create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
/* 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);
if (fi->unwind->type != UNKNOWN_FRAME)
fi->type = fi->unwind->type;
else
fi->type = frame_type_from_pc (pc);
fi->this_id.p = 1;
deprecated_update_frame_base_hack (fi, addr);
@ -1194,440 +1031,6 @@ reinit_frame_cache (void)
}
}
/* Create the previous frame using the deprecated methods
INIT_EXTRA_INFO, and INIT_FRAME_PC. */
static struct frame_info *
legacy_get_prev_frame (struct frame_info *this_frame)
{
CORE_ADDR address = 0;
struct frame_info *prev;
int fromleaf;
/* Don't frame_debug print legacy_get_prev_frame() here, just
confuses the output. */
/* Allocate the new 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
memory allocation calls. */
prev = FRAME_OBSTACK_ZALLOC (struct frame_info);
prev->level = this_frame->level + 1;
/* 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).
On the other hand, methods, such as get_frame_pc() and
get_frame_base() rely on being able to walk along the frame
chain. Make certain that at least they work by providing that
link. Of course things manipulating prev can't go back. */
prev->next = this_frame;
/* 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, 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
to NORMAL_FRAME. Ulgh! The new frame code does not have this
problem. */
prev->type = UNKNOWN_FRAME;
/* A legacy frame's ID is always computed here. Mark it as valid. */
prev->this_id.p = 1;
/* Handle sentinel frame unwind as a special case. */
if (this_frame->level < 0)
{
/* 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, 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
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. */
deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame));
if (get_frame_pc (prev) == 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 legacy PC zero }\n");
}
return NULL;
}
/* 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->prologue_cache);
if (prev->unwind->type == UNKNOWN_FRAME)
prev->type = frame_type_from_pc (get_frame_pc (prev));
else
prev->type = prev->unwind->type;
/* Find the prev's frame's ID. */
if (prev->type == DUMMY_FRAME
&& gdbarch_unwind_dummy_id_p (current_gdbarch))
{
/* When unwinding a normal frame, the stack structure is
determined by analyzing the frame's function's code (be
it using brute force prologue analysis, or the dwarf2
CFI). In the case of a dummy frame, that simply isn't
possible. The The PC is either the program entry point,
or some random address on the stack. Trying to use that
PC to apply standard frame ID unwind techniques is just
asking for trouble. */
/* Use an architecture specific method to extract the prev's
dummy ID from the next frame. Note that this method uses
frame_register_unwind to obtain the register values
needed to determine the dummy frame's ID. */
prev->this_id.value = gdbarch_unwind_dummy_id (current_gdbarch,
this_frame);
}
else
{
/* We're unwinding a sentinel frame, the PC of which is
pointing at a stack dummy. Fake up the dummy frame's ID
using the same sequence as is found a traditional
unwinder. Once all architectures supply the
unwind_dummy_id method, this code can go away. */
prev->this_id.value = frame_id_build (deprecated_read_fp (),
read_pc ());
}
/* Check that the unwound ID is valid. */
if (!frame_id_p (prev->this_id.value))
{
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, NULL);
fprintf_unfiltered (gdb_stdlog,
" // unwound legacy ID invalid }\n");
}
return NULL;
}
/* Check that the new frame isn't inner to (younger, below,
next) the old frame. If that happens the frame unwind is
going backwards. */
/* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
that doesn't have a valid frame ID. Should instead set the
sentinel frame's frame ID to a `sentinel'. Leave it until
after the switch to storing the frame ID, instead of the
frame base, in the frame object. */
/* Link it in. */
this_frame->prev = prev;
/* FIXME: cagney/2002-01-19: This call will go away. Instead of
initializing extra info, all frames will use the frame_cache
(passed to the unwind functions) to store additional frame
info. Unfortunately legacy targets can't use
legacy_get_prev_frame() to unwind the sentinel frame and,
consequently, are forced to take this code path and rely on
the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
initialize the inner-most frame. */
if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
{
DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev);
}
if (prev->type == NORMAL_FRAME)
prev->this_id.value.code_addr
= get_pc_function_start (prev->this_id.value.code_addr);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, prev);
fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n");
}
return prev;
}
/* This code only works on normal frames. A sentinel frame, where
the level is -1, should never reach this code. */
gdb_assert (this_frame->level >= 0);
/* On some machines it is possible to call a function without
setting up a stack frame for it. On these machines, we
define this macro to take two args; a frameinfo pointer
identifying a frame and a variable to set or clear if it is
or isn't leafless. */
/* Still don't want to worry about this except on the innermost
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 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 = (DEPRECATED_FRAMELESS_FUNCTION_INVOCATION_P ()
&& DEPRECATED_FRAMELESS_FUNCTION_INVOCATION (this_frame));
else
fromleaf = 0;
if (fromleaf)
/* A frameless inner-most frame. The `FP' (which isn't an
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 handle
it locally. */
/* FIXME: cagney/2003-06-16: This returns the inner most stack
address for the previous frame, that, however, is wrong. It
should be the inner most stack address for the previous to
previous frame. This is because it is the previous to previous
frame's innermost stack address that is constant through out
the lifetime of the previous frame (trust me :-). */
address = get_frame_base (this_frame);
else
{
/* Two macros defined in tm.h specify the machine-dependent
actions to be performed here.
First, get the frame's chain-pointer.
If that is zero, the frame is the outermost frame or a leaf
called by the outermost frame. This means that if start
calls main without a frame, we'll return 0 (which is fine
anyway).
Nope; there's a problem. This also returns when the current
routine is a leaf of main. This is unacceptable. We move
this to after the ffi test; I'd rather have backtraces from
start go curfluy than have an abort called from main not show
main. */
if (DEPRECATED_FRAME_CHAIN_P ())
address = DEPRECATED_FRAME_CHAIN (this_frame);
else
{
/* Someone is part way through coverting an old architecture
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,
&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,
&prev->prologue_cache,
&prev->this_id.value);
prev->this_id.p = 1;
address = prev->this_id.value.stack_addr;
}
if (!legacy_frame_chain_valid (address, this_frame))
{
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, NULL);
fprintf_unfiltered (gdb_stdlog,
" // legacy frame chain invalid }\n");
}
return NULL;
}
}
if (address == 0)
{
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, NULL);
fprintf_unfiltered (gdb_stdlog,
" // legacy frame chain NULL }\n");
}
return NULL;
}
/* Link in the already allocated prev frame. */
this_frame->prev = prev;
deprecated_update_frame_base_hack (prev, address);
/* This change should not be needed, FIXME! We should determine
whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
way to express what goes on here.
DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
create_new_frame (where the PC is already set up) and here (where
it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
requires the PC value (which hasn't been set yet). Some other
machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
(deprecated_read_fp ()), read_pc ()). Machines with extra frame
info would do that (or the local equivalent) and then set the
extra fields.
SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
create_new_frame would no longer init extra frame info;
SETUP_ARBITRARY_FRAME would have to do that.
INIT_PREV_FRAME(fromleaf, prev) Replace
DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
This should also return a flag saying whether to keep the new
frame, or whether to discard it, because on some machines (e.g.
mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
into the extra fields of the new frame). std_frame_pc(fromleaf,
prev)
This is the default setting for INIT_PREV_FRAME. It just does
what the default DEPRECATED_INIT_FRAME_PC does. Some machines
will call it from INIT_PREV_FRAME (either at the beginning, the
end, or in the middle). Some machines won't use it.
kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
/* NOTE: cagney/2002-11-09: Just ignore the above! There is no
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 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 the standard
frame_XX_unwind() functions and not differentiate between the
inner most and any other case.
Since there is always a frame to unwind from, there is always
somewhere (THIS_FRAME) to store all the info needed to construct
a new (previous) frame without having to first create it. This
means that the convolution below - needing to carefully order a
frame's initialization - isn't needed.
The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
for a more up-to-date architecture, always calls
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 superseded by
frame_pc_unwind() and that function does have somewhere to cache
that PC value. */
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. */
if (DEPRECATED_INIT_FRAME_PC_P ())
deprecated_update_frame_pc_hack (prev,
DEPRECATED_INIT_FRAME_PC (fromleaf,
prev));
/* If ->frame and ->pc are unchanged, we are in the process of
getting ourselves into an infinite backtrace. Some architectures
check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
like there is no reason this can't be an architecture-independent
check. */
if (get_frame_base (prev) == get_frame_base (this_frame)
&& get_frame_pc (prev) == get_frame_pc (this_frame))
{
this_frame->prev = NULL;
obstack_free (&frame_cache_obstack, prev);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, NULL);
fprintf_unfiltered (gdb_stdlog,
" // legacy this.id == prev.id }\n");
}
return NULL;
}
/* Initialize the code used to unwind the frame PREV based on the PC
(and probably other architectural information). The PC lets you
check things like the debug info at that point (dwarf2cfi?) and
use that to decide how the frame should be unwound.
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->prologue_cache);
/* If the unwinder provides a frame type, use it. Otherwise
continue on to that heuristic mess. */
if (prev->unwind->type != UNKNOWN_FRAME)
{
prev->type = prev->unwind->type;
if (prev->type == NORMAL_FRAME)
/* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */
prev->this_id.value.code_addr
= get_pc_function_start (prev->this_id.value.code_addr);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, prev);
fprintf_unfiltered (gdb_stdlog, " } // legacy with unwound type\n");
}
return prev;
}
/* NOTE: cagney/2002-11-18: The code segments, found in
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_pc_in_call_dummy (get_frame_pc (prev)))
prev->type = DUMMY_FRAME;
if (prev->type == NORMAL_FRAME)
prev->this_id.value.code_addr
= get_pc_function_start (prev->this_id.value.code_addr);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, prev);
fprintf_unfiltered (gdb_stdlog, " } // legacy with confused type\n");
}
return prev;
}
/* Return a "struct frame_info" corresponding to the frame that called
THIS_FRAME. Returns NULL if there is no such frame.
@ -1665,14 +1068,6 @@ get_prev_frame_1 (struct frame_info *this_frame)
}
this_frame->prev_p = 1;
/* If any of the old frame initialization methods are around, use
the legacy get_prev_frame() method. */
if (legacy_frame_p (current_gdbarch))
{
prev_frame = legacy_get_prev_frame (this_frame);
return prev_frame;
}
/* Check that this frame's ID was valid. If it wasn't, don't try to
unwind to the prev frame. Be careful to not apply this test to
the sentinel frame. */
@ -1693,7 +1088,7 @@ get_prev_frame_1 (struct frame_info *this_frame)
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
&& this_frame->next->unwind->type != SIGTRAMP_FRAME
&& frame_id_inner (this_id, get_frame_id (this_frame->next)))
error ("Previous frame inner to this frame (corrupt stack?)");
@ -1870,7 +1265,7 @@ get_prev_frame (struct frame_info *this_frame)
#if 0
&& backtrace_beyond_entry_func
#endif
&& this_frame->type != DUMMY_FRAME && this_frame->level >= 0
&& this_frame->unwind->type != DUMMY_FRAME && this_frame->level >= 0
&& inside_entry_func (this_frame))
{
frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
@ -2012,26 +1407,12 @@ frame_relative_level (struct frame_info *fi)
enum frame_type
get_frame_type (struct frame_info *frame)
{
/* Some legacy code, e.g, mips_init_extra_frame_info() wants
to determine the frame's type prior to it being completely
initialized. Don't attempt to lazily initialize ->unwind for
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 that's what
provides the frame's type. */
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 NORMAL_FRAME;
else
return frame->type;
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);
return frame->unwind->type;
}
struct frame_extra_info *
@ -2169,33 +1550,6 @@ frame_sp_unwind (struct frame_info *next_frame)
internal_error (__FILE__, __LINE__, "Missing unwind SP method");
}
int
legacy_frame_p (struct gdbarch *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 */
static struct cmd_list_element *set_backtrace_cmdlist;

22
gdb/frame.h
View File

@ -71,10 +71,6 @@ struct block;
struct gdbarch;
struct ui_file;
/* A legacy unwinder to prop up architectures using the old style
saved regs array. */
extern const struct frame_unwind *legacy_saved_regs_unwind;
/* The frame object. */
struct frame_info;
@ -375,11 +371,6 @@ extern int frame_relative_level (struct frame_info *fi);
enum frame_type
{
/* The frame's type hasn't yet been defined. This is a catch-all
for legacy_get_prev_frame that uses really strange techniques to
determine the frame's type. New code should not use this
value. */
UNKNOWN_FRAME,
/* A true stack frame, created by the target program during normal
execution. */
NORMAL_FRAME,
@ -527,15 +518,6 @@ extern void *frame_obstack_zalloc (unsigned long size);
#define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
#define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
/* If legacy_frame_chain_valid() returns zero it means that the given
frame is the outermost one and has no caller.
This method has been superseded by the per-architecture
frame_unwind_pc() (returns 0 to indicate an invalid return address)
and per-frame this_id() (returns a NULL frame ID to indicate an
invalid frame). */
extern int legacy_frame_chain_valid (CORE_ADDR, struct frame_info *);
extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
extern struct block *get_frame_block (struct frame_info *,
@ -718,8 +700,4 @@ extern void deprecated_update_frame_base_hack (struct frame_info *frame,
extern struct frame_info *deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs,
long sizeof_extra_info);
/* Return non-zero if the architecture is relying on legacy frame
code. */
extern int legacy_frame_p (struct gdbarch *gdbarch);
#endif /* !defined (FRAME_H) */