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[patch, rfc, 6.0] Change frame predicates to sniffers
- From: Andrew Cagney <ac131313 at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Fri, 11 Jul 2003 17:57:24 -0400
- Subject: [patch, rfc, 6.0] Change frame predicates to sniffers
Hello,
This patch adds frame sniffers (name stolen from other sniffer code) to
the frame code. Unlike the existing frame predicate methods that take a
PC parameter, these take a full NEXT_FRAME. It leaves the old frame
predicates alone (making this safe for the branch).
I figure that should be enough to keep any unwinder, trying to decide if
the frame is good, happy :-)
I'll look to commit this to both the trunk and 6.0 branch early next
week. I'll then follow up with patches to:
- rips out the old predicate methods (mainline only)
- replace the dwarf2 predicate with a dwarf2 sniffer
Will apply to mainline and branch. Should fix weird edge case where a
function has no cfi but is doing a tail call to a no-return function,
but the code following the function does have CFI.
- (I guess) something to work around the dwarf2 unwind info (need to
look at Mark's old code)
I've so far tested it on a RH9 system (with the sniffer enabled) and it
hasn't shown a sign of regressing.
Can anyone point me at testcases that will magically start passing with
this fixed?
Andrew
2003-07-11 Andrew Cagney <cagney@redhat.com>
* frame.c (get_frame_id): Use frame_unwind_find_by_frame.
(frame_register_unwind, create_new_frame): Ditto.
(legacy_get_prev_frame, get_frame_type): Ditto.
(get_frame_base_address): Use frame_base_find_by_frame.
(get_frame_locals_address): Use frame_base_find_by_frame.
(get_frame_args_address): Use frame_base_find_by_frame.
* frame-base.h (frame_base_sniffer_ftype): Declare.
(frame_base_append_sniffer): Declare.
(frame_base_find_by_frame): Replace frame_base_find_by_pc.
* frame-base.c (append_predicate): Add a "sniffer" parameter.
(frame_base_append_sniffer): New function.
(frame_base_append_predicate): Add a NULL sniffer.
(frame_base_find_by_frame): Replace "frame_base_find_by_pc".
(struct frame_base_table): Add "sniffer".
(frame_base_free): Free the "sniffer" table.
* frame-unwind.h (frame_unwind_sniffer_ftype): Define.
(frame_unwind_append_sniffer): Declare.
(frame_unwind_find_by_frame): Replace frame_unwind_find_by_pc.
* frame-unwind.c (frame_unwind_free): Free the "sniffer" table.
(struct frame_unwind_table): Add "sniffer", delete "middle".
(append_predicate): Add "sniffer" parameter, append the sniffer.
(frame_unwind_init): Update append_predicate call.
(frame_unwind_append_sniffer): New function.
(frame_unwind_append_predicate): Update append_predicate call.
(frame_unwind_find_by_frame): Replace frame_unwind_find_by_pc.
Index: frame-base.c
===================================================================
RCS file: /cvs/src/src/gdb/frame-base.c,v
retrieving revision 1.5
diff -u -r1.5 frame-base.c
--- frame-base.c 26 Jun 2003 17:18:41 -0000 1.5
+++ frame-base.c 11 Jul 2003 21:40:14 -0000
@@ -71,6 +71,7 @@
struct frame_base_table
{
frame_base_p_ftype **p;
+ frame_base_sniffer_ftype **sniffer;
const struct frame_base *default_base;
int nr;
};
@@ -89,6 +90,7 @@
struct frame_base_table *table =
gdbarch_data (gdbarch, frame_base_data);
xfree (table->p);
+ xfree (table->sniffer);
xfree (table);
}
@@ -108,11 +110,16 @@
/* Append a predicate to the end of the table. */
static void
-append_predicate (struct frame_base_table *table, frame_base_p_ftype *p)
+append_predicate (struct frame_base_table *table, frame_base_p_ftype *p,
+ frame_base_sniffer_ftype *sniffer)
{
table->p = xrealloc (table->p, ((table->nr + 1)
* sizeof (frame_base_p_ftype *)));
+ table->sniffer = xrealloc (table->sniffer,
+ ((table->nr + 1)
+ * sizeof (frame_base_sniffer_ftype *)));
table->p[table->nr] = p;
+ table->sniffer[table->nr] = sniffer;
table->nr++;
}
@@ -121,7 +128,15 @@
frame_base_p_ftype *p)
{
struct frame_base_table *table = frame_base_table (gdbarch);
- append_predicate (table, p);
+ append_predicate (table, p, NULL);
+}
+
+void
+frame_base_append_sniffer (struct gdbarch *gdbarch,
+ frame_base_sniffer_ftype *sniffer)
+{
+ struct frame_base_table *table = frame_base_table (gdbarch);
+ append_predicate (table, NULL, sniffer);
}
void
@@ -133,13 +148,18 @@
}
const struct frame_base *
-frame_base_find_by_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
+frame_base_find_by_frame (struct frame_info *next_frame)
{
- int i;
+ struct gdbarch *gdbarch = get_frame_arch (next_frame);
struct frame_base_table *table = frame_base_table (gdbarch);
+ int i;
for (i = 0; i < table->nr; i++)
{
- const struct frame_base *desc = table->p[i] (pc);
+ const struct frame_base *desc = NULL;
+ if (table->p[i] != NULL)
+ desc = table->p[i] (frame_pc_unwind (next_frame));
+ else if (table->sniffer[i] != NULL)
+ desc = table->sniffer[i] (next_frame);
if (desc != NULL)
return desc;
}
Index: frame-base.h
===================================================================
RCS file: /cvs/src/src/gdb/frame-base.h,v
retrieving revision 1.1
diff -u -r1.1 frame-base.h
--- frame-base.h 1 Apr 2003 19:11:01 -0000 1.1
+++ frame-base.h 11 Jul 2003 21:40:14 -0000
@@ -29,30 +29,12 @@
struct gdbarch;
struct regcache;
-/* Return the frame base methods for the function that contains PC, or
- NULL if it can't handle this frame. */
+/* For compatibility. */
typedef const struct frame_base *(frame_base_p_ftype) (CORE_ADDR pc);
-
-/* Add a frame base handler to the list. The predicates are polled in
- the order that they are appended. */
-
extern void frame_base_append_predicate (struct gdbarch *gdbarch,
frame_base_p_ftype *p);
-/* Set the default frame base. If all else fails, this one is
- returned. If this isn't set, the default is to use legacy code
- that uses things like the frame ID's base (ulgh!). */
-
-extern void frame_base_set_default (struct gdbarch *gdbarch,
- const struct frame_base *def);
-
-/* Iterate through the list of frame base handlers until one returns
- an implementation. */
-
-extern const struct frame_base *frame_base_find_by_pc (struct gdbarch *gdbarch,
- CORE_ADDR pc);
-
/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
and that this is a `normal frame'; use the NEXT frame, and its
register unwind method, to determine the address of THIS frame's
@@ -90,5 +72,28 @@
frame_this_locals_ftype *this_locals;
frame_this_args_ftype *this_args;
};
+
+/* Given the NEXT frame, return the frame base methods for THIS frame,
+ or NULL if it can't handle THIS frame. */
+
+typedef const struct frame_base *(frame_base_sniffer_ftype) (struct frame_info *next_frame);
+
+/* Append a frame base sniffer to the list. The sniffers are polled
+ in the order that they are appended. */
+
+extern void frame_base_append_sniffer (struct gdbarch *gdbarch,
+ frame_base_sniffer_ftype *sniffer);
+
+/* Set the default frame base. If all else fails, this one is
+ returned. If this isn't set, the default is to use legacy code
+ that uses things like the frame ID's base (ulgh!). */
+
+extern void frame_base_set_default (struct gdbarch *gdbarch,
+ const struct frame_base *def);
+
+/* Iterate through the list of frame base handlers until one returns
+ an implementation. */
+
+extern const struct frame_base *frame_base_find_by_frame (struct frame_info *next_frame);
#endif
Index: frame-unwind.c
===================================================================
RCS file: /cvs/src/src/gdb/frame-unwind.c,v
retrieving revision 1.4
diff -u -r1.4 frame-unwind.c
--- frame-unwind.c 8 Jun 2003 18:27:13 -0000 1.4
+++ frame-unwind.c 11 Jul 2003 21:40:14 -0000
@@ -30,17 +30,21 @@
struct frame_unwind_table
{
frame_unwind_p_ftype **p;
- int middle;
+ frame_unwind_sniffer_ftype **sniffer;
int nr;
};
/* Append a predicate to the end of the table. */
static void
-append_predicate (struct frame_unwind_table *table, frame_unwind_p_ftype *p)
+append_predicate (struct frame_unwind_table *table, frame_unwind_p_ftype *p,
+ frame_unwind_sniffer_ftype *sniffer)
{
table->p = xrealloc (table->p, ((table->nr + 1)
* sizeof (frame_unwind_p_ftype *)));
+ table->sniffer = xrealloc (table->sniffer, ((table->nr + 1)
+ * sizeof (frame_unwind_sniffer_ftype *)));
table->p[table->nr] = p;
+ table->sniffer[table->nr] = sniffer;
table->nr++;
}
@@ -48,7 +52,7 @@
frame_unwind_init (struct gdbarch *gdbarch)
{
struct frame_unwind_table *table = XCALLOC (1, struct frame_unwind_table);
- append_predicate (table, dummy_frame_p);
+ append_predicate (table, dummy_frame_p, NULL);
return table;
}
@@ -58,6 +62,7 @@
struct frame_unwind_table *table =
gdbarch_data (gdbarch, frame_unwind_data);
xfree (table->p);
+ xfree (table->sniffer);
xfree (table);
}
@@ -74,15 +79,31 @@
table = frame_unwind_init (gdbarch);
set_gdbarch_data (gdbarch, frame_unwind_data, table);
}
- append_predicate (table, p);
+ append_predicate (table, p, NULL);
}
-const struct frame_unwind *
-frame_unwind_find_by_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
+void
+frame_unwind_append_sniffer (struct gdbarch *gdbarch,
+ frame_unwind_sniffer_ftype *sniffer)
{
- int i;
struct frame_unwind_table *table =
gdbarch_data (gdbarch, frame_unwind_data);
+ if (table == NULL)
+ {
+ /* ULGH, called during architecture initialization. Patch
+ things up. */
+ table = frame_unwind_init (gdbarch);
+ set_gdbarch_data (gdbarch, frame_unwind_data, table);
+ }
+ append_predicate (table, NULL, sniffer);
+}
+
+const struct frame_unwind *
+frame_unwind_find_by_frame (struct frame_info *next_frame)
+{
+ int i;
+ struct gdbarch *gdbarch = get_frame_arch (next_frame);
+ struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
/* Seriously old code. Don't even try to use this new mechanism.
(Note: The variable USE_GENERIC_DUMMY_FRAMES is deprecated, not
@@ -91,7 +112,13 @@
return legacy_saved_regs_unwind;
for (i = 0; i < table->nr; i++)
{
- const struct frame_unwind *desc = table->p[i] (pc);
+ const struct frame_unwind *desc;
+ if (table->p[i] != NULL)
+ desc = table->p[i] (frame_pc_unwind (next_frame));
+ else if (table->sniffer[i] != NULL)
+ desc = table->sniffer[i] (next_frame);
+ else
+ internal_error (__FILE__, __LINE__, "Missing sniffer?");
if (desc != NULL)
return desc;
}
Index: frame-unwind.h
===================================================================
RCS file: /cvs/src/src/gdb/frame-unwind.h,v
retrieving revision 1.7
diff -u -r1.7 frame-unwind.h
--- frame-unwind.h 5 Apr 2003 03:55:59 -0000 1.7
+++ frame-unwind.h 11 Jul 2003 21:40:14 -0000
@@ -30,25 +30,12 @@
#include "frame.h" /* For enum frame_type. */
-/* Return the frame unwind methods for the function that contains PC,
- or NULL if this this unwinder can't handle this frame. */
-
+/* For compatibility with the old frame code. See end of header for
+ new methods. */
typedef const struct frame_unwind *(frame_unwind_p_ftype) (CORE_ADDR pc);
-
-/* Add a frame unwinder to the list. The predicates are polled in the
- order that they are appended. The initial list contains the dummy
- frame's predicate. */
-
extern void frame_unwind_append_predicate (struct gdbarch *gdbarch,
frame_unwind_p_ftype *p);
-/* Iterate through the list of frame unwinders until one returns an
- implementation. */
-
-extern const struct frame_unwind *frame_unwind_find_by_pc (struct gdbarch
- *gdbarch,
- CORE_ADDR pc);
-
/* The following unwind functions assume a chain of frames forming the
sequence: (outer) prev <-> this <-> next (inner). All the
functions are called with called with the next frame's `struct
@@ -138,5 +125,23 @@
frame_this_id_ftype *this_id;
frame_prev_register_ftype *prev_register;
};
+
+/* Given the NEXT frame, take a wiff of THIS frame's registers (namely
+ the PC and attributes) and if it is the applicable unwinder return
+ the unwind methods, or NULL if it is not. */
+
+typedef const struct frame_unwind *(frame_unwind_sniffer_ftype) (struct frame_info *next_frame);
+
+/* Add a frame sniffer to the list. The predicates are polled in the
+ order that they are appended. The initial list contains the dummy
+ frame sniffer. */
+
+extern void frame_unwind_append_sniffer (struct gdbarch *gdbarch,
+ frame_unwind_sniffer_ftype *sniffer);
+
+/* Iterate through the next frame's sniffers until one returns with an
+ unwinder implementation. */
+
+extern const struct frame_unwind *frame_unwind_find_by_frame (struct frame_info *next_frame);
#endif
Index: frame.c
===================================================================
RCS file: /cvs/src/src/gdb/frame.c,v
retrieving revision 1.131
diff -u -r1.131 frame.c
--- frame.c 11 Jul 2003 14:52:17 -0000 1.131
+++ frame.c 11 Jul 2003 21:40:16 -0000
@@ -229,8 +229,7 @@
/* Find the unwinder. */
if (fi->unwind == NULL)
{
- fi->unwind = frame_unwind_find_by_pc (current_gdbarch,
- get_frame_pc (fi));
+ 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. Unfortunatly, legacy code, called by
@@ -517,8 +516,7 @@
/* Find the unwinder. */
if (frame->unwind == NULL)
{
- frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
- get_frame_pc (frame));
+ 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. Unfortunatly, legacy code, called by
@@ -1206,7 +1204,7 @@
/* Select/initialize both the unwind function and the frame's type
based on the PC. */
- fi->unwind = frame_unwind_find_by_pc (current_gdbarch, pc);
+ fi->unwind = frame_unwind_find_by_frame (fi->next);
if (fi->unwind->type != UNKNOWN_FRAME)
fi->type = fi->unwind->type;
else
@@ -1365,8 +1363,7 @@
/* 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_pc (current_gdbarch,
- get_frame_pc (prev));
+ prev->unwind = frame_unwind_find_by_frame (prev->next);
if (prev->unwind->type == UNKNOWN_FRAME)
prev->type = frame_type_from_pc (get_frame_pc (prev));
else
@@ -1514,8 +1511,7 @@
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_pc (current_gdbarch,
- frame_pc_unwind (this_frame));
+ 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. Unfortunatly, legacy code, called by
@@ -1676,8 +1672,7 @@
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_pc (current_gdbarch,
- get_frame_pc (prev));
+ prev->unwind = frame_unwind_find_by_frame (prev->next);
/* If the unwinder provides a frame type, use it. Otherwize
continue on to that heuristic mess. */
@@ -2072,7 +2067,7 @@
if (get_frame_type (fi) != NORMAL_FRAME)
return 0;
if (fi->base == NULL)
- fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ fi->base = frame_base_find_by_frame (fi->next);
/* 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)
@@ -2088,7 +2083,7 @@
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ fi->base = frame_base_find_by_frame (fi->next);
/* 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)
@@ -2106,7 +2101,7 @@
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ fi->base = frame_base_find_by_frame (fi->next);
/* 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)
@@ -2145,8 +2140,7 @@
{
/* Initialize the frame's unwinder because it is that which
provides the frame's type. */
- frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
- get_frame_pc (frame));
+ 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. Unfortunatly, legacy code, called by