* Re: [unwind-20030108-branch] Add sentinel-frame + misc
2003-01-10 2:17 [unwind-20030108-branch] Add sentinel-frame + misc Andrew Cagney
@ 2003-01-10 6:45 ` Andrew Cagney
2003-01-10 21:33 ` Daniel Jacobowitz
0 siblings, 1 reply; 7+ messages in thread
From: Andrew Cagney @ 2003-01-10 6:45 UTC (permalink / raw)
To: gdb-patches
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with patch,
> This adds sentinal-frame.[hc] and then modifies the unwind code in frame.c so that it can exploit the fact that there is alway an extra frame beyond the inner most frame. This has a dramatic effect on the unwind code - so much simpler!
>
> It doesn't do things like ensure that there is always a frame or create the inner most frame from the sentinel frame.
>
> To confuse the patch slightly, it also adjusts the id_unwind, pc_unwind and register_unwind function types.
>
> Andrew
>
>
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2003-01-09 Andrew Cagney <ac131313@redhat.com>
* dummy-frame.h (dummy_frame_id_unwind): Update.
(dummy_frame_pc_unwind): Update.
(dummy_frame_register_unwind): Update.
* dummy-frame.c: Update.
* frame.c (create_new_frame): Set next to a sentinal frame.
(create_sentinel_frame): New function.
(frame_id_unwind): Update id_unwind call.
(frame_saved_regs_register_unwind): Update cache parameter.
(frame_saved_regs_pc_unwind): Update cache parameter.
(frame_saved_regs_id_unwind): Update cache and id parameters.
* frame.h (frame_id_unwind_ftype): Return the frame ID using a
reference parameter.
(struct frame_unwind_cache): Declare.
(frame_id_unwind_ftype, frame_pc_unwind_ftype,
frame_register_unwind_ftype): Change the unwind cache_type to
`struct frame_unwind_cache'.
(struct frame_info): Change type of unwind_cache to `struct
frame_unwind_cache'.
* frame.c (get_next_frame): Don't go beyond the inner-most frame.
(frame_register_unwind): Assume that there is always a next frame.
(frame_register): Ditto.
(generic_unwind_get_saved_register): Ditto.
* frame.h (frame_type): Add SENTINEL_FRAME.
* Makefile.in (frame.o): Update dependencies.
* frame.h (FRAME_OBSTACK_ZALLOC): Define.
* Makefile.in (sentinel-frame.o): Specify dependencies.
(sentinel_frame_h): Define.
(SFILES): Add sentinel-frame.c.
(COMMON_OBS): Add sentinel-frame.o.
* sentinel-frame.c: New file.
* sentinel-frame.h: New file.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.311
diff -u -r1.311 Makefile.in
--- Makefile.in 9 Jan 2003 18:03:35 -0000 1.311
+++ Makefile.in 10 Jan 2003 02:08:38 -0000
@@ -521,7 +521,8 @@
objfiles.c osabi.c \
p-exp.y p-lang.c p-typeprint.c p-valprint.c parse.c printcmd.c \
regcache.c reggroups.c remote.c \
- scm-exp.c scm-lang.c scm-valprint.c serial.c ser-unix.c source.c \
+ scm-exp.c scm-lang.c scm-valprint.c sentinel-frame.c \
+ serial.c ser-unix.c source.c \
stabsread.c stack.c std-regs.c symfile.c symmisc.c symtab.c \
target.c thread.c top.c tracepoint.c typeprint.c \
tui/tui.c tui/tui.h tui/tuiCommand.c tui/tuiCommand.h \
@@ -678,6 +679,7 @@
remote_h = remote.h
scm_lang_h = scm-lang.h $(scm_tags_h)
scm_tags_h = scm-tags.h
+sentinel_frame_h = sentinel-frame.h
ser_unix_h = ser-unix.h
serial_h = serial.h
sh_tdep_h = sh-tdep.h
@@ -831,6 +833,7 @@
ui-file.o \
frame.o doublest.o \
gnu-v2-abi.o gnu-v3-abi.o hpacc-abi.o cp-abi.o cp-support.o \
+ sentinel-frame.o \
reggroups.o
OBS = $(COMMON_OBS) $(ANNOTATE_OBS)
@@ -1679,7 +1682,7 @@
frame.o: frame.c $(defs_h) $(frame_h) $(target_h) $(value_h) $(inferior_h) \
$(regcache_h) $(gdb_assert_h) $(gdb_string_h) $(builtin_regs_h) \
$(gdb_obstack_h) $(dummy_frame_h) $(gdbcore_h) $(annotate_h) \
- $(language_h)
+ $(language_h) $(sentinel_frame_h)
frv-tdep.o: frv-tdep.c $(defs_h) $(inferior_h) $(symfile_h) $(gdbcore_h) \
$(arch_utils_h) $(regcache_h)
gcore.o: gcore.c $(defs_h) $(cli_decode_h) $(inferior_h) $(gdbcore_h) \
@@ -2110,6 +2113,8 @@
scm-valprint.o: scm-valprint.c $(defs_h) $(symtab_h) $(gdbtypes_h) \
$(expression_h) $(parser_defs_h) $(language_h) $(value_h) \
$(scm_lang_h) $(valprint_h) $(gdbcore_h)
+sentinel-frame.o: sentinel-frame.c $(defs_h) $(regcache_h) \
+ $(sentinel_frame_h) $(inferior_h)
ser-e7kpc.o: ser-e7kpc.c $(defs_h) $(serial_h) $(gdb_string_h)
ser-go32.o: ser-go32.c $(defs_h) $(gdbcmd_h) $(serial_h) $(gdb_string_h)
ser-pipe.o: ser-pipe.c $(defs_h) $(serial_h) $(ser_unix_h) $(gdb_vfork_h) \
Index: dummy-frame.c
===================================================================
RCS file: /cvs/src/src/gdb/dummy-frame.c,v
retrieving revision 1.7
diff -u -r1.7 dummy-frame.c
--- dummy-frame.c 13 Dec 2002 16:40:25 -0000 1.7
+++ dummy-frame.c 10 Jan 2003 02:08:38 -0000
@@ -33,9 +33,9 @@
up the inferior function call. Older targets save the registers
on the target stack (but that really slows down function calls). */
-struct dummy_frame
+struct frame_unwind_cache
{
- struct dummy_frame *next;
+ struct frame_unwind_cache *next;
/* These values belong to the caller (the previous frame, the frame
that this unwinds back to). */
@@ -52,7 +52,7 @@
CORE_ADDR call_hi;
};
-static struct dummy_frame *dummy_frame_stack = NULL;
+static struct frame_unwind_cache *dummy_frame_stack = NULL;
/* Function: find_dummy_frame(pc, fp, sp)
@@ -61,10 +61,10 @@
adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
to call this function after the PC has been adjusted. */
-static struct dummy_frame *
+static struct frame_unwind_cache *
find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
- struct dummy_frame *dummyframe;
+ struct frame_unwind_cache *dummyframe;
for (dummyframe = dummy_frame_stack; dummyframe != NULL;
dummyframe = dummyframe->next)
@@ -103,8 +103,9 @@
return NULL;
}
-struct dummy_frame *
-cached_find_dummy_frame (struct frame_info *frame, void **cache)
+struct frame_unwind_cache *
+cached_find_dummy_frame (struct frame_info *frame,
+ struct frame_unwind_cache **cache)
{
if ((*cache) == NULL)
(*cache) = find_dummy_frame (get_frame_pc (frame), get_frame_base (frame));
@@ -114,7 +115,7 @@
struct regcache *
generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
- struct dummy_frame *dummy = find_dummy_frame (pc, fp);
+ struct frame_unwind_cache *dummy = find_dummy_frame (pc, fp);
if (dummy != NULL)
return dummy->regcache;
else
@@ -158,7 +159,7 @@
int
pc_in_dummy_frame (CORE_ADDR pc)
{
- struct dummy_frame *dummyframe;
+ struct frame_unwind_cache *dummyframe;
for (dummyframe = dummy_frame_stack;
dummyframe != NULL;
dummyframe = dummyframe->next)
@@ -207,7 +208,7 @@
void
generic_push_dummy_frame (void)
{
- struct dummy_frame *dummy_frame;
+ struct frame_unwind_cache *dummy_frame;
CORE_ADDR fp = get_frame_base (get_current_frame ());
/* check to see if there are stale dummy frames,
@@ -226,7 +227,7 @@
else
dummy_frame = dummy_frame->next;
- dummy_frame = xmalloc (sizeof (struct dummy_frame));
+ dummy_frame = XMALLOC (struct frame_unwind_cache);
dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
dummy_frame->pc = read_pc ();
@@ -275,7 +276,7 @@
void
generic_pop_dummy_frame (void)
{
- struct dummy_frame *dummy_frame = dummy_frame_stack;
+ struct frame_unwind_cache *dummy_frame = dummy_frame_stack;
/* FIXME: what if the first frame isn't the right one, eg..
because one call-by-hand function has done a longjmp into another one? */
@@ -305,12 +306,13 @@
register value is taken from the local copy of the register buffer. */
void
-dummy_frame_register_unwind (struct frame_info *frame, void **cache,
+dummy_frame_register_unwind (struct frame_info *frame,
+ struct frame_unwind_cache **cache,
int regnum, int *optimized,
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnum, void *bufferp)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
+ struct frame_unwind_cache *dummy = cached_find_dummy_frame (frame, cache);
gdb_assert (dummy != NULL);
/* Describe the register's location. Generic dummy frames always
@@ -333,9 +335,9 @@
CORE_ADDR
dummy_frame_pc_unwind (struct frame_info *frame,
- void **cache)
+ struct frame_unwind_cache **cache)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
+ struct frame_unwind_cache *dummy = cached_find_dummy_frame (frame, cache);
/* Oops! In a dummy-frame but can't find the stack dummy. Pretend
that the frame doesn't unwind. Should this function instead
return a has-no-caller indication? */
@@ -345,16 +347,18 @@
}
-struct frame_id
+void
dummy_frame_id_unwind (struct frame_info *frame,
- void **cache)
+ struct frame_unwind_cache **cache,
+ struct frame_id *id)
{
- struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
+ struct frame_unwind_cache *dummy = cached_find_dummy_frame (frame, cache);
/* Oops! In a dummy-frame but can't find the stack dummy. Pretend
that the frame doesn't unwind. Should this function instead
return a has-no-caller indication? */
if (dummy == NULL)
- return null_frame_id;
- return dummy->id;
+ *id = null_frame_id;
+ else
+ *id = dummy->id;
}
Index: dummy-frame.h
===================================================================
RCS file: /cvs/src/src/gdb/dummy-frame.h,v
retrieving revision 1.5
diff -u -r1.5 dummy-frame.h
--- dummy-frame.h 13 Dec 2002 16:40:25 -0000 1.5
+++ dummy-frame.h 10 Jan 2003 02:08:38 -0000
@@ -24,6 +24,8 @@
struct frame_info;
struct regcache;
+struct frame_id;
+struct frame_unwind_cache;
/* GENERIC DUMMY FRAMES
@@ -46,7 +48,7 @@
previous frame. */
extern void dummy_frame_register_unwind (struct frame_info *frame,
- void **unwind_cache,
+ struct frame_unwind_cache **unwind_cache,
int regnum,
int *optimized,
enum lval_type *lvalp,
@@ -58,13 +60,14 @@
previous frame. */
extern CORE_ADDR dummy_frame_pc_unwind (struct frame_info *frame,
- void **unwind_cache);
+ struct frame_unwind_cache **unwind_cache);
/* Assuming that FRAME is a dummy, return the ID of the calling frame
(the frame that the dummy has the saved state of). */
-extern struct frame_id dummy_frame_id_unwind (struct frame_info *frame,
- void **unwind_cache);
+extern void dummy_frame_id_unwind (struct frame_info *frame,
+ struct frame_unwind_cache **unwind_cache,
+ struct frame_id *id);
/* Does the PC fall in a dummy frame?
Index: frame.c
===================================================================
RCS file: /cvs/src/src/gdb/frame.c,v
retrieving revision 1.56
diff -u -r1.56 frame.c
--- frame.c 9 Jan 2003 18:53:20 -0000 1.56
+++ frame.c 10 Jan 2003 02:08:38 -0000
@@ -31,6 +31,7 @@
#include "builtin-regs.h"
#include "gdb_obstack.h"
#include "dummy-frame.h"
+#include "sentinel-frame.h"
#include "gdbcore.h"
#include "annotate.h"
#include "language.h"
@@ -138,8 +139,7 @@
{
if (!frame->id_unwind_cache_p)
{
- frame->id_unwind_cache =
- frame->id_unwind (frame, &frame->unwind_cache);
+ frame->id_unwind (frame, &frame->unwind_cache, &frame->id_unwind_cache);
frame->id_unwind_cache_p = 1;
}
return frame->id_unwind_cache;
@@ -161,29 +161,11 @@
gdb_assert (realnump != NULL);
/* gdb_assert (bufferp != NULL); */
- /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
- special case, there was always an inner frame dedicated to the
- hardware registers. Unfortunatly, there is too much unwind code
- around that looks up/down the frame chain while making the
- assumption that each frame level is using the same unwind code. */
-
- if (frame == NULL)
- {
- /* We're in the inner-most frame, get the value direct from the
- register cache. */
- *optimizedp = 0;
- *lvalp = lval_register;
- /* ULGH! Code uses the offset into the raw register byte array
- as a way of identifying a register. */
- *addrp = REGISTER_BYTE (regnum);
- /* Should this code test ``register_cached (regnum) < 0'' and do
- something like set realnum to -1 when the register isn't
- available? */
- *realnump = regnum;
- if (bufferp)
- deprecated_read_register_gen (regnum, bufferp);
- return;
- }
+ /* 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
+ detected the problem before calling here. */
+ gdb_assert (frame != NULL);
/* Ask this frame to unwind its register. */
frame->register_unwind (frame, &frame->unwind_cache, regnum,
@@ -229,25 +211,11 @@
return;
}
- /* Reached the the bottom (youngest, inner most) of the frame chain
- (youngest, inner most) frame, go direct to the hardware register
- cache (do not pass go, do not try to cache the value, ...). The
- unwound value would have been cached in frame->next but that
- doesn't exist. This doesn't matter as the hardware register
- cache is stopping any unnecessary accesses to the target. */
-
- /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
- special case, there was always an inner frame dedicated to the
- hardware registers. Unfortunatly, there is too much unwind code
- around that looks up/down the frame chain while making the
- assumption that each frame level is using the same unwind code. */
-
- if (frame == NULL)
- frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, realnump,
- bufferp);
- else
- frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
- realnump, bufferp);
+ /* Obtain the register value by unwinding the register from the next
+ (more inner frame). */
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
+ realnump, bufferp);
}
void
@@ -337,25 +305,9 @@
if (addrp == NULL)
addrp = &addrx;
- /* Reached the the bottom (youngest, inner most) of the frame chain
- (youngest, inner most) frame, go direct to the hardware register
- cache (do not pass go, do not try to cache the value, ...). The
- unwound value would have been cached in frame->next but that
- doesn't exist. This doesn't matter as the hardware register
- cache is stopping any unnecessary accesses to the target. */
-
- /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
- special case, there was always an inner frame dedicated to the
- hardware registers. Unfortunatly, there is too much unwind code
- around that looks up/down the frame chain while making the
- assumption that each frame level is using the same unwind code. */
-
- if (frame == NULL)
- frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, &realnumx,
- raw_buffer);
- else
- frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
- &realnumx, raw_buffer);
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
+ &realnumx, raw_buffer);
}
void
@@ -445,6 +397,21 @@
return builtin_reg_map_regnum_to_name (regnum);
}
+/* Create the sentinel frame. */
+
+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;
+ frame->unwind_cache = sentinel_frame_cache (regcache);
+ frame->pc_unwind = sentinel_frame_pc_unwind;
+ frame->id_unwind = sentinel_frame_id_unwind;
+ frame->register_unwind = sentinel_frame_register_unwind;
+ return frame;
+}
+
/* Info about the innermost stack frame (contents of FP register) */
static struct frame_info *current_frame;
@@ -555,8 +522,14 @@
If the value isn't here AND a value is needed, try the next inner
most frame. */
+struct frame_unwind_cache
+{
+ void *regs[1];
+};
+
static void
-frame_saved_regs_register_unwind (struct frame_info *frame, void **cache,
+frame_saved_regs_register_unwind (struct frame_info *frame,
+ struct frame_unwind_cache **cache,
int regnum, int *optimizedp,
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnump, void *bufferp)
@@ -601,22 +574,22 @@
#if 1
/* Save each register value, as it is read in, in a
frame based cache. */
- void **regs = (*cache);
- if (regs == NULL)
+ if ((*cache) == NULL)
{
int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
* sizeof (void *));
- regs = frame_obstack_zalloc (sizeof_cache);
- (*cache) = regs;
+ (*cache) = frame_obstack_zalloc (sizeof_cache);
}
- if (regs[regnum] == NULL)
+ if ((*cache)->regs[regnum] == NULL)
{
- regs[regnum]
+ (*cache)->regs[regnum]
= frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum));
- read_memory (frame->saved_regs[regnum], regs[regnum],
+ read_memory (frame->saved_regs[regnum],
+ (*cache)->regs[regnum],
REGISTER_RAW_SIZE (regnum));
}
- memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum));
+ memcpy (bufferp, (*cache)->regs[regnum],
+ REGISTER_RAW_SIZE (regnum));
#else
/* Read the value in from memory. */
read_memory (frame->saved_regs[regnum], bufferp,
@@ -646,16 +619,18 @@
}
static CORE_ADDR
-frame_saved_regs_pc_unwind (struct frame_info *frame, void **cache)
+frame_saved_regs_pc_unwind (struct frame_info *frame,
+ struct frame_unwind_cache **cache)
{
return FRAME_SAVED_PC (frame);
}
-static struct frame_id
-frame_saved_regs_id_unwind (struct frame_info *next_frame, void **cache)
+static void
+frame_saved_regs_id_unwind (struct frame_info *next_frame,
+ struct frame_unwind_cache **cache,
+ struct frame_id *id)
{
int fromleaf;
- struct frame_id id;
if (next_frame->next == NULL)
/* FIXME: 2002-11-09: Frameless functions can occure anywhere in
@@ -673,7 +648,7 @@
/* FIXME: 2002-11-09: There isn't any reason to special case this
edge condition. Instead the per-architecture code should hande
it locally. */
- id.base = get_frame_base (next_frame);
+ id->base = get_frame_base (next_frame);
else
{
/* Two macros defined in tm.h specify the machine-dependent
@@ -691,18 +666,24 @@
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. */
- id.base = FRAME_CHAIN (next_frame);
+ id->base = FRAME_CHAIN (next_frame);
- if (!frame_chain_valid (id.base, next_frame))
- return null_frame_id;
+ if (!frame_chain_valid (id->base, next_frame))
+ {
+ *id = null_frame_id;
+ return;
+ }
+ }
+ if (id->base == 0)
+ {
+ *id = null_frame_id;
+ return;
}
- if (id.base == 0)
- return null_frame_id;
/* FIXME: cagney/2002-06-08: This should probably return the frame's
function and not the PC (a.k.a. resume address). */
- id.pc = frame_pc_unwind (next_frame);
- return id;
+ id->pc = frame_pc_unwind (next_frame);
+ return;
}
/* Function: get_saved_register
@@ -851,6 +832,7 @@
fi->frame = addr;
fi->pc = pc;
+ fi->next = create_sentinel_frame (current_regcache);
/* 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
@@ -892,7 +874,12 @@
struct frame_info *
get_next_frame (struct frame_info *frame)
{
- return frame->next;
+ /* Don't fall off the bottom of the frame chain. This code has an
+ extra magic frame, don't expose that externally. */
+ if (frame->level > 0)
+ return frame->next;
+ else
+ return NULL;
}
/* Flush the entire frame cache. */
Index: frame.h
===================================================================
RCS file: /cvs/src/src/gdb/frame.h,v
retrieving revision 1.59
diff -u -r1.59 frame.h
--- frame.h 9 Jan 2003 18:53:21 -0000 1.59
+++ frame.h 10 Jan 2003 02:08:39 -0000
@@ -29,6 +29,9 @@
struct frame_info;
+/* The frame unwind cache object. */
+struct frame_unwind_cache;
+
/* The frame object's ID. This provides a per-frame unique identifier
that can be used to relocate a `struct frame_info' after a target
resume or a frame cache destruct. It of course assumes that the
@@ -229,7 +232,10 @@
DUMMY_FRAME,
/* In a signal handler, various OSs handle this in various ways.
The main thing is that the frame may be far from normal. */
- SIGTRAMP_FRAME
+ SIGTRAMP_FRAME,
+ /* The sentinel frame. Marks the inner-most end of the chain of
+ frames. */
+ SENTINEL_FRAME
};
extern enum frame_type get_frame_type (struct frame_info *);
@@ -318,7 +324,7 @@
in the register "i1" in this FRAME. */
typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
- void **unwind_cache,
+ struct frame_unwind_cache **unwind_cache,
int regnum,
int *optimized,
enum lval_type *lvalp,
@@ -330,13 +336,14 @@
calling frame would resume. */
typedef CORE_ADDR (frame_pc_unwind_ftype) (struct frame_info *frame,
- void **unwind_cache);
+ struct frame_unwind_cache **unwind_cache);
/* Same as for registers above, but return the ID of the frame that
called this one. */
-typedef struct frame_id (frame_id_unwind_ftype) (struct frame_info *frame,
- void **unwind_cache);
+typedef void (frame_id_unwind_ftype) (struct frame_info *frame,
+ struct frame_unwind_cache **unwind_cache,
+ struct frame_id *id);
/* Describe the saved registers of a frame. */
@@ -423,7 +430,7 @@
/* Unwind cache shared between the unwind functions - they had
better all agree as to the contents. */
- void *unwind_cache;
+ struct frame_unwind_cache *unwind_cache;
/* See description above. The previous frame's registers. */
frame_register_unwind_ftype *register_unwind;
@@ -477,6 +484,7 @@
allocate memory using this method. */
extern void *frame_obstack_zalloc (unsigned long size);
+#define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
/* If FRAME_CHAIN_VALID returns zero it means that the given frame
is the outermost one and has no caller. */
^ permalink raw reply [flat|nested] 7+ messages in thread