#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"
+#include "frame-unwind.h"
+#include "command.h"
+#include "gdbcmd.h"
+
+/* Flag to indicate whether backtraces should stop at main. */
+
+static int backtrace_below_main;
/* Return a frame uniq ID that can be used to, later, re-find the
frame. */
{
if (!frame->pc_unwind_cache_p)
{
- frame->pc_unwind_cache = frame->pc_unwind (frame, &frame->unwind_cache);
+ frame->pc_unwind_cache = frame->unwind->pc (frame, &frame->unwind_cache);
frame->pc_unwind_cache_p = 1;
}
return frame->pc_unwind_cache;
{
if (!frame->id_unwind_cache_p)
{
- frame->id_unwind_cache =
- frame->id_unwind (frame, &frame->unwind_cache);
+ frame->unwind->id (frame, &frame->unwind_cache, &frame->id_unwind_cache);
frame->id_unwind_cache_p = 1;
}
return frame->id_unwind_cache;
}
+void
+frame_pop (struct frame_info *frame)
+{
+ /* FIXME: cagney/2003-01-18: There is probably a chicken-egg problem
+ with passing in current_regcache. The pop function needs to be
+ written carefully so as to not overwrite registers whose [old]
+ values are needed to restore other registers. Instead, this code
+ should pass in a scratch cache and, as a second step, restore the
+ registers using that. */
+ frame->unwind->pop (frame, &frame->unwind_cache, current_regcache);
+ flush_cached_frames ();
+}
void
frame_register_unwind (struct frame_info *frame, int regnum,
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,
- optimizedp, lvalp, addrp, realnump, bufferp);
+ frame->unwind->reg (frame, &frame->unwind_cache, regnum,
+ optimizedp, lvalp, addrp, realnump, bufferp);
}
void
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
tests like ``if get_next_frame() == NULL'' and instead just rely
on recursive frame calls (like the below code) when manipulating
a frame chain. */
- gdb_assert (frame != NULL);
- frame_unwind_unsigned_register (get_next_frame (frame), regnum, val);
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_unwind_unsigned_register (frame->next, regnum, val);
}
void
frame_read_signed_register (struct frame_info *frame, int regnum,
LONGEST *val)
{
- /* See note in frame_read_unsigned_register(). */
- gdb_assert (frame != NULL);
- frame_unwind_signed_register (get_next_frame (frame), regnum, val);
+ /* See note above in frame_read_unsigned_register(). */
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_unwind_signed_register (frame->next, regnum, val);
}
static void
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
return builtin_reg_map_regnum_to_name (regnum);
}
+/* Create a sentinel frame. */
+
+struct frame_info *
+create_sentinel_frame (struct regcache *regcache)
+{
+ struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
+ frame->type = NORMAL_FRAME;
+ frame->level = -1;
+ /* Explicitly initialize the sentinel frame's cache. Provide it
+ with the underlying regcache. In the future additional
+ information, such as the frame's thread will be added. */
+ frame->unwind_cache = sentinel_frame_cache (regcache);
+ /* For the moment there is only one sentinel frame implementation. */
+ frame->unwind = sentinel_frame_unwind;
+ /* Link this frame back to itself. The frame is self referential
+ (the unwound PC is the same as the pc), so make it so. */
+ frame->next = frame;
+ /* Always unwind the PC as part of creating this frame. This
+ ensures that the frame's PC points at something valid. */
+ /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel
+ frame's PC may require information such as the frame's thread's
+ stop reason. Is it possible to get to that? */
+ frame->pc = frame_pc_unwind (frame);
+ return frame;
+}
+
/* Info about the innermost stack frame (contents of FP register) */
static struct frame_info *current_frame;
static struct obstack frame_cache_obstack;
void *
-frame_obstack_alloc (unsigned long size)
+frame_obstack_zalloc (unsigned long size)
{
- return obstack_alloc (&frame_cache_obstack, size);
+ void *data = obstack_alloc (&frame_cache_obstack, size);
+ memset (data, 0, size);
+ return data;
}
CORE_ADDR *
frame_saved_regs_zalloc (struct frame_info *fi)
{
fi->saved_regs = (CORE_ADDR *)
- frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
- memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
+ frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS);
return fi->saved_regs;
}
return fi->saved_regs;
}
-/* Return the innermost (currently executing) stack frame. */
+/* Return the innermost (currently executing) stack frame. This is
+ split into two functions. The function unwind_to_current_frame()
+ is wrapped in catch exceptions so that, even when the unwind of the
+ sentinel frame fails, the function still returns a stack frame. */
+
+static int
+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
+ lands in somewhere like start. */
+ if (frame == NULL)
+ return 1;
+ current_frame = frame;
+ return 0;
+}
struct frame_info *
get_current_frame (void)
{
+ if (!target_has_stack)
+ error ("No stack.");
+ if (!target_has_registers)
+ error ("No registers.");
+ if (!target_has_memory)
+ error ("No memory.");
if (current_frame == NULL)
{
- if (target_has_stack)
- current_frame = create_new_frame (read_fp (), read_pc ());
- else
- error ("No stack.");
+ struct frame_info *sentinel_frame =
+ create_sentinel_frame (current_regcache);
+ if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame,
+ NULL, RETURN_MASK_ERROR) != 0)
+ {
+ /* Oops! Fake a current frame? Is this useful? It has a PC
+ of zero, for instance. */
+ current_frame = sentinel_frame;
+ }
}
return current_frame;
}
gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES
&& (get_frame_type (frame) == DUMMY_FRAME)));
+ /* Only (older) architectures that implement the
+ FRAME_INIT_SAVED_REGS method should be using this function. */
+ gdb_assert (FRAME_INIT_SAVED_REGS_P ());
+
/* Load the saved_regs register cache. */
- if (frame->saved_regs == NULL)
+ if (get_frame_saved_regs (frame) == NULL)
FRAME_INIT_SAVED_REGS (frame);
- if (frame->saved_regs != NULL
- && frame->saved_regs[regnum] != 0)
+ if (get_frame_saved_regs (frame) != NULL
+ && get_frame_saved_regs (frame)[regnum] != 0)
{
if (regnum == SP_REGNUM)
{
*realnump = -1;
if (bufferp != NULL)
store_address (bufferp, REGISTER_RAW_SIZE (regnum),
- frame->saved_regs[regnum]);
+ get_frame_saved_regs (frame)[regnum]);
}
else
{
a local copy of its value. */
*optimizedp = 0;
*lvalp = lval_memory;
- *addrp = frame->saved_regs[regnum];
+ *addrp = get_frame_saved_regs (frame)[regnum];
*realnump = -1;
if (bufferp != NULL)
{
{
int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
* sizeof (void *));
- regs = frame_obstack_alloc (sizeof_cache);
- memset (regs, 0, sizeof_cache);
+ regs = frame_obstack_zalloc (sizeof_cache);
(*cache) = regs;
}
if (regs[regnum] == NULL)
{
regs[regnum]
- = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum));
- read_memory (frame->saved_regs[regnum], regs[regnum],
+ = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum));
+ read_memory (get_frame_saved_regs (frame)[regnum], regs[regnum],
REGISTER_RAW_SIZE (regnum));
}
memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum));
#else
/* Read the value in from memory. */
- read_memory (frame->saved_regs[regnum], bufferp,
+ read_memory (get_frame_saved_regs (frame)[regnum], bufferp,
REGISTER_RAW_SIZE (regnum));
#endif
}
}
/* No luck, assume this and the next frame have the same register
- value. If a value is needed, pass the request on down the chain;
- otherwise just return an indication that the value is in the same
- register as the next frame. */
- if (bufferp == NULL)
- {
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realnump = regnum;
- }
- else
- {
- frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
- realnump, bufferp);
- }
+ value. Pass the request down the frame chain to the next frame.
+ Hopefully that will find the register's location, either in a
+ register or in memory. */
+ frame_register (frame, regnum, optimizedp, lvalp, addrp, realnump,
+ bufferp);
}
static CORE_ADDR
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, void **cache,
+ struct frame_id *id)
{
int fromleaf;
- struct frame_id id;
+ CORE_ADDR base;
+ CORE_ADDR pc;
+
+ /* Start out by assuming it's NULL. */
+ (*id) = null_frame_id;
- if (next_frame->next == NULL)
+ if (frame_relative_level (next_frame) <= 0)
/* FIXME: 2002-11-09: Frameless functions can occure anywhere in
the frame chain, not just the inner most frame! The generic,
per-architecture, frame code should handle this and the below
/* 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);
+ base = get_frame_base (next_frame);
else
{
/* Two macros defined in tm.h specify the machine-dependent
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);
+ base = FRAME_CHAIN (next_frame);
- if (!frame_chain_valid (id.base, next_frame))
- return null_frame_id;
+ if (!frame_chain_valid (base, next_frame))
+ return;
}
- if (id.base == 0)
- return null_frame_id;
+ if (base == 0)
+ return;
/* 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;
+ pc = frame_pc_unwind (next_frame);
+ id->pc = pc;
+ id->base = base;
}
+static void
+frame_saved_regs_pop (struct frame_info *fi, void **cache,
+ struct regcache *regcache)
+{
+ gdb_assert (POP_FRAME_P ());
+ POP_FRAME;
+}
+
+const struct frame_unwind trad_frame_unwinder = {
+ frame_saved_regs_pop,
+ frame_saved_regs_pc_unwind,
+ frame_saved_regs_id_unwind,
+ frame_saved_regs_register_unwind
+};
+const struct frame_unwind *trad_frame_unwind = &trad_frame_unwinder;
+
+
/* Function: get_saved_register
Find register number REGNUM relative to FRAME and put its (raw,
target format) contents in *RAW_BUFFER.
if (!target_has_registers)
error ("No registers.");
+ gdb_assert (FRAME_INIT_SAVED_REGS_P ());
+
/* Normal systems don't optimize out things with register numbers. */
if (optimized != NULL)
*optimized = 0;
the current frame itself: otherwise, we would be getting the
previous frame's registers which were saved by the current frame. */
- while (frame && ((frame = frame->next) != NULL))
+ if (frame != NULL)
{
- 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 (generic_find_dummy_frame (frame->pc,
- frame->frame),
- regnum, raw_buffer);
- return;
- }
-
- FRAME_INIT_SAVED_REGS (frame);
- if (frame->saved_regs != NULL
- && frame->saved_regs[regnum] != 0)
+ for (frame = get_next_frame (frame);
+ frame_relative_level (frame) >= 0;
+ frame = get_next_frame (frame))
{
- if (lval) /* found it saved on the stack */
- *lval = lval_memory;
- if (regnum == SP_REGNUM)
+ if (get_frame_type (frame) == DUMMY_FRAME)
{
- if (raw_buffer) /* SP register treated specially */
- store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
- frame->saved_regs[regnum]);
+ 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
+ (generic_find_dummy_frame (get_frame_pc (frame),
+ get_frame_base (frame)),
+ regnum, raw_buffer);
+ return;
}
- else
+
+ FRAME_INIT_SAVED_REGS (frame);
+ if (get_frame_saved_regs (frame) != NULL
+ && get_frame_saved_regs (frame)[regnum] != 0)
{
- if (addrp) /* any other register */
- *addrp = frame->saved_regs[regnum];
- if (raw_buffer)
- read_memory (frame->saved_regs[regnum], raw_buffer,
- REGISTER_RAW_SIZE (regnum));
+ if (lval) /* found it saved on the stack */
+ *lval = lval_memory;
+ if (regnum == SP_REGNUM)
+ {
+ if (raw_buffer) /* SP register treated specially */
+ store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
+ get_frame_saved_regs (frame)[regnum]);
+ }
+ else
+ {
+ if (addrp) /* any other register */
+ *addrp = get_frame_saved_regs (frame)[regnum];
+ if (raw_buffer)
+ read_memory (get_frame_saved_regs (frame)[regnum], raw_buffer,
+ REGISTER_RAW_SIZE (regnum));
+ }
+ return;
}
- return;
}
}
deprecated_read_register_gen (regnum, raw_buffer);
}
-/* Using the PC, select a mechanism for unwinding a frame returning
- the previous frame. The register unwind function should, on
- demand, initialize the ->context object. */
+/* Determine the frame's type based on its PC. */
-static void
-set_unwind_by_pc (CORE_ADDR pc, CORE_ADDR fp,
- frame_register_unwind_ftype **unwind_register,
- frame_pc_unwind_ftype **unwind_pc,
- frame_id_unwind_ftype **unwind_id)
+static enum frame_type
+frame_type_from_pc (CORE_ADDR pc)
{
- if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
- {
- /* Still need to set this to something. The ``info frame'' code
- calls this function to find out where the saved registers are.
- Hopefully this is robust enough to stop any core dumps and
- return vaguely correct values.. */
- *unwind_register = frame_saved_regs_register_unwind;
- *unwind_pc = frame_saved_regs_pc_unwind;
- *unwind_id = frame_saved_regs_id_unwind;
- }
- else if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
- ? DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)
- : pc_in_dummy_frame (pc))
- {
- *unwind_register = dummy_frame_register_unwind;
- *unwind_pc = dummy_frame_pc_unwind;
- *unwind_id = dummy_frame_id_unwind;
- }
+ /* 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))
+ return DUMMY_FRAME;
else
{
- *unwind_register = frame_saved_regs_register_unwind;
- *unwind_pc = frame_saved_regs_pc_unwind;
- *unwind_id = frame_saved_regs_id_unwind;
+ char *name;
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (PC_IN_SIGTRAMP (pc, name))
+ return SIGTRAMP_FRAME;
+ else
+ return NORMAL_FRAME;
}
}
create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
{
struct frame_info *fi;
- enum frame_type type;
-
- fi = (struct frame_info *)
- obstack_alloc (&frame_cache_obstack,
- sizeof (struct frame_info));
- /* Zero all fields by default. */
- memset (fi, 0, sizeof (struct frame_info));
+ fi = frame_obstack_zalloc (sizeof (struct frame_info));
fi->frame = addr;
fi->pc = pc;
- /* 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
- 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 (pc, 0, 0)
- : pc_in_dummy_frame (pc)))
- /* NOTE: cagney/2002-11-11: Does this even occure? */
- type = DUMMY_FRAME;
- else
- {
- char *name;
- find_pc_partial_function (pc, &name, NULL, NULL);
- if (PC_IN_SIGTRAMP (fi->pc, name))
- type = SIGTRAMP_FRAME;
- else
- type = NORMAL_FRAME;
- }
- fi->type = type;
+ fi->next = create_sentinel_frame (current_regcache);
+ fi->type = frame_type_from_pc (pc);
if (INIT_EXTRA_FRAME_INFO_P ())
INIT_EXTRA_FRAME_INFO (0, fi);
/* Select/initialize an unwind function. */
- set_unwind_by_pc (fi->pc, fi->frame, &fi->register_unwind,
- &fi->pc_unwind, &fi->id_unwind);
+ fi->unwind = frame_unwind_find_by_pc (current_gdbarch, fi->pc);
return fi;
}
/* Return the frame that FRAME calls (NULL if FRAME is the innermost
- frame). */
+ frame). Be careful to not fall off the bottom of the frame chain
+ and onto the sentinel frame. */
struct frame_info *
get_next_frame (struct frame_info *frame)
{
- return frame->next;
+ if (frame->level > 0)
+ return frame->next;
+ else
+ return NULL;
}
/* Flush the entire frame cache. */
}
}
-/* Return a structure containing various interesting information
- about the frame that called NEXT_FRAME. Returns NULL
- if there is no such frame. */
+/* Create the previous frame using the deprecated methods
+ INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
-struct frame_info *
-get_prev_frame (struct frame_info *next_frame)
+static struct frame_info *
+legacy_get_prev_frame (struct frame_info *next_frame)
{
CORE_ADDR address = 0;
struct frame_info *prev;
int fromleaf;
- /* 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. */
- if (next_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
- NEXT_FRAME. */
- return current_frame;
- }
-
- /* Only try to do the unwind once. */
- if (next_frame->prev_p)
- return next_frame->prev;
- next_frame->prev_p = 1;
+ /* This code only works on normal frames. A sentinel frame, where
+ the level is -1, should never reach this code. */
+ gdb_assert (next_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
/* Still don't want to worry about this except on the innermost
frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
function invocation. */
- if (next_frame->next == NULL)
+ if (next_frame->level == 0)
/* FIXME: 2002-11-09: Frameless functions can occure anywhere in
the frame chain, not just the inner most frame! The generic,
per-architecture, frame code should handle this and the below
return 0;
/* Create an initially zero previous frame. */
- prev = (struct frame_info *)
- obstack_alloc (&frame_cache_obstack,
- sizeof (struct frame_info));
- memset (prev, 0, sizeof (struct frame_info));
+ prev = frame_obstack_zalloc (sizeof (struct frame_info));
/* Link it in. */
next_frame->prev = prev;
(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. */
- set_unwind_by_pc (prev->pc, prev->frame, &prev->register_unwind,
- &prev->pc_unwind, &prev->id_unwind);
+ prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc);
/* NOTE: cagney/2002-11-18: The code segments, found in
create_new_frame and get_prev_frame(), that initializes the
return prev;
}
+/* Return a structure containing various interesting information
+ about the frame that called NEXT_FRAME. Returns NULL
+ if there is no such frame. */
+
+struct frame_info *
+get_prev_frame (struct frame_info *next_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 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 (next_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
+ NEXT_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 (next_frame != NULL);
+
+ if (next_frame->level >= 0
+ && !backtrace_below_main
+ && inside_main_func (get_frame_pc (next_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. */
+ return NULL;
+
+ /* Only try to do the unwind once. */
+ if (next_frame->prev_p)
+ return next_frame->prev;
+ next_frame->prev_p = 1;
+
+ /* If we're inside the entry file, it isn't valid. */
+ /* 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. */
+ if (inside_entry_file (get_frame_pc (next_frame)))
+ return NULL;
+
+ /* If any of the old frame initialization methods are around, use
+ the legacy get_prev_frame method. Just don't try to unwind a
+ sentinel frame using that method - it doesn't work. All sentinal
+ frames use the new unwind code. */
+ if ((DEPRECATED_INIT_FRAME_PC_P ()
+ || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
+ || INIT_EXTRA_FRAME_INFO_P ())
+ && next_frame->level >= 0)
+ return legacy_get_prev_frame (next_frame);
+
+ /* Allocate the new frame but do not wire it in to the frame chain.
+ Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
+ frame->next to pull some fancy tricks (of course such code is, by
+ definition, recursive). Try to prevent it.
+
+ 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 above will stop repeated memory
+ allocation calls. */
+ prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
+ prev_frame->level = next_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 FRAME_CHAIN()) assume
+ NEXT_FRAME's data structures have already been initialized (using
+ 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 NEXT_FRAME's frame ID. */
+
+ prev_frame->pc = frame_pc_unwind (next_frame);
+ if (prev_frame->pc == 0)
+ /* The allocated PREV_FRAME will be reclaimed when the frame
+ obstack is next purged. */
+ return NULL;
+ prev_frame->type = frame_type_from_pc (prev_frame->pc);
+
+ /* Set the unwind functions based on that identified PC. */
+ prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ prev_frame->pc);
+
+ /* FIXME: cagney/2003-01-13: A dummy frame doesn't need to unwind
+ the frame ID because the frame ID comes from the previous frame.
+ The other frames do though. True? */
+ {
+ /* FIXME: cagney/2002-12-18: Instead of this hack, should just
+ save the frame ID directly. */
+ struct frame_id id = frame_id_unwind (next_frame);
+ if (!frame_id_p (id))
+ return NULL;
+ prev_frame->frame = id.base;
+ }
+
+ /* Link it in. */
+ next_frame->prev = prev_frame;
+ prev_frame->next = next_frame;
+
+ /* 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.
+ Unfortunatly 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 INIT_EXTR_FRAME_INFO
+ to initialize the inner-most frame. */
+ if (INIT_EXTRA_FRAME_INFO_P ())
+ {
+ gdb_assert (prev_frame->level == 0);
+ INIT_EXTRA_FRAME_INFO (0, prev_frame);
+ }
+
+ return prev_frame;
+}
+
CORE_ADDR
get_frame_pc (struct frame_info *frame)
{
if (frame->saved_regs == NULL)
{
frame->saved_regs = (CORE_ADDR *)
- frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
+ frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS);
}
if (saved_regs_addr == NULL)
{
struct frame_extra_info *
frame_extra_info_zalloc (struct frame_info *fi, long size)
{
- fi->extra_info = frame_obstack_alloc (size);
- memset (fi->extra_info, 0, size);
+ fi->extra_info = frame_obstack_zalloc (size);
return fi->extra_info;
}
deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc)
{
/* See comment in "frame.h". */
+ gdb_assert (frame->next != NULL);
frame->pc = pc;
}
frame->extra_info = extra_info;
}
+void
+deprecated_set_frame_next_hack (struct frame_info *fi,
+ struct frame_info *next)
+{
+ fi->next = next;
+}
+
+void
+deprecated_set_frame_prev_hack (struct frame_info *fi,
+ struct frame_info *prev)
+{
+ fi->prev = prev;
+}
+
+struct context *
+deprecated_get_frame_context (struct frame_info *fi)
+{
+ return fi->context;
+}
+
+void
+deprecated_set_frame_context (struct frame_info *fi,
+ struct context *context)
+{
+ fi->context = context;
+}
+
struct frame_info *
deprecated_frame_xmalloc (void)
{
_initialize_frame (void)
{
obstack_init (&frame_cache_obstack);
+
+ /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest
+ `set backtrace {past,beyond,...}-main'. Also suggest adding `set
+ backtrace ...-start' to control backtraces past start. The
+ problem with `below' is that it stops the `up' command. */
+
+ add_setshow_boolean_cmd ("backtrace-below-main", class_obscure,
+ &backtrace_below_main, "\
+Set whether backtraces should continue past \"main\".\n\
+Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
+the backtrace at \"main\". Set this variable if you need to see the rest\n\
+of the stack trace.", "\
+Show whether backtraces should continue past \"main\".\n\
+Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
+the backtrace at \"main\". Set this variable if you need to see the rest\n\
+of the stack trace.",
+ NULL, NULL, &setlist, &showlist);
}
projects / deliverable / binutils-gdb.git / blobdiff