/* Cache and manage frames for GDB, the GNU debugger.
Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000,
- 2001, 2002 Free Software Foundation, Inc.
+ 2001, 2002, 2003 Free Software Foundation, Inc.
This file is part of GDB.
#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"
-/* Return a frame uniq ID that can be used to, later re-find the
+/* 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. */
-void
-get_frame_id (struct frame_info *fi, struct frame_id *id)
+struct frame_id
+get_frame_id (struct frame_info *fi)
{
if (fi == NULL)
{
- id->base = 0;
- id->pc = 0;
+ return null_frame_id;
}
else
{
- id->base = fi->frame;
- id->pc = fi->pc;
+ struct frame_id id;
+ id.base = fi->frame;
+ id.pc = fi->pc;
+ return id;
}
}
+const struct frame_id null_frame_id; /* All zeros. */
+
+struct frame_id
+frame_id_build (CORE_ADDR base, CORE_ADDR func_or_pc)
+{
+ struct frame_id id;
+ id.base = base;
+ id.pc = func_or_pc;
+ return id;
+}
+
+int
+frame_id_p (struct frame_id l)
+{
+ /* The .func can be NULL but the .base cannot. */
+ return (l.base != 0);
+}
+
+int
+frame_id_eq (struct frame_id l, struct frame_id r)
+{
+ /* If .base is different, the frames are different. */
+ if (l.base != r.base)
+ return 0;
+ /* Add a test to check that the frame ID's are for the same function
+ here. */
+ return 1;
+}
+
+int
+frame_id_inner (struct frame_id l, struct frame_id r)
+{
+ /* Only return non-zero when strictly inner than. Note that, per
+ comment in "frame.h", there is some fuzz here. Frameless
+ functions are not strictly inner than (same .base but different
+ .func). */
+ return INNER_THAN (l.base, r.base);
+}
+
struct frame_info *
frame_find_by_id (struct frame_id id)
{
/* ZERO denotes the null frame, let the caller decide what to do
about it. Should it instead return get_current_frame()? */
- if (id.base == 0 && id.pc == 0)
+ if (!frame_id_p (id))
return NULL;
for (frame = get_current_frame ();
frame != NULL;
frame = get_prev_frame (frame))
{
- struct frame_id this;
- get_frame_id (frame, &this);
- if (INNER_THAN (this.base, id.base))
- /* ``inner/current < frame < id.base''. Keep looking along
- the frame chain. */
- continue;
- if (INNER_THAN (id.base, this.base))
- /* ``inner/current < id.base < frame''. Oops, gone past it.
- Just give up. */
+ struct frame_id this = get_frame_id (frame);
+ if (frame_id_eq (id, this))
+ /* An exact match. */
+ return frame;
+ if (frame_id_inner (id, this))
+ /* Gone to far. */
return NULL;
- /* FIXME: cagney/2002-04-21: This isn't sufficient. It should
- use id.pc / this.pc to check that the two frames belong to
- the same function. Otherwise we'll do things like match
- dummy frames or mis-match frameless functions. However,
- until someone notices, stick with the existing behavour. */
- return frame;
+ /* Either, we're not yet gone far enough out along the frame
+ chain (inner(this,id), or we're comparing frameless functions
+ (same .base, different .func, no test available). Struggle
+ on until we've definitly gone to far. */
}
return NULL;
}
{
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;
}
+struct frame_id
+frame_id_unwind (struct frame_info *frame)
+{
+ if (!frame->id_unwind_cache_p)
+ {
+ 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,
int *optimizedp, enum lval_type *lvalp,
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;
}
-void
+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;
+}
+
+CORE_ADDR *
+get_frame_saved_regs (struct frame_info *fi)
+{
+ return fi->saved_regs;
}
+/* 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. */
-/* Return the innermost (currently executing) 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;
}
+/* The "selected" stack frame is used by default for local and arg
+ access. May be zero, for no selected frame. */
+
+struct frame_info *deprecated_selected_frame;
+
+/* Return the selected frame. Always non-null (unless there isn't an
+ inferior sufficient for creating a frame) in which case an error is
+ thrown. */
+
+struct frame_info *
+get_selected_frame (void)
+{
+ if (deprecated_selected_frame == NULL)
+ /* Hey! Don't trust this. It should really be re-finding the
+ last selected frame of the currently selected thread. This,
+ though, is better than nothing. */
+ select_frame (get_current_frame ());
+ /* There is always a frame. */
+ gdb_assert (deprecated_selected_frame != NULL);
+ return deprecated_selected_frame;
+}
+
+/* Select frame FI (or NULL - to invalidate the current frame). */
+
void
-set_current_frame (struct frame_info *frame)
+select_frame (struct frame_info *fi)
{
- current_frame = frame;
+ register struct symtab *s;
+
+ deprecated_selected_frame = fi;
+ /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
+ frame is being invalidated. */
+ if (selected_frame_level_changed_hook)
+ selected_frame_level_changed_hook (frame_relative_level (fi));
+
+ /* FIXME: kseitz/2002-08-28: It would be nice to call
+ selected_frame_level_changed_event right here, but due to limitations
+ in the current interfaces, we would end up flooding UIs with events
+ because select_frame is used extensively internally.
+
+ Once we have frame-parameterized frame (and frame-related) commands,
+ the event notification can be moved here, since this function will only
+ be called when the users selected frame is being changed. */
+
+ /* Ensure that symbols for this frame are read in. Also, determine the
+ source language of this frame, and switch to it if desired. */
+ if (fi)
+ {
+ s = find_pc_symtab (fi->pc);
+ if (s
+ && s->language != current_language->la_language
+ && s->language != language_unknown
+ && language_mode == language_mode_auto)
+ {
+ set_language (s->language);
+ }
+ }
}
/* Return the register saved in the simplistic ``saved_regs'' cache.
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 void
+frame_saved_regs_id_unwind (struct frame_info *next_frame, void **cache,
+ struct frame_id *id)
+{
+ int fromleaf;
+ CORE_ADDR base;
+ CORE_ADDR pc;
+
+ /* Start out by assuming it's NULL. */
+ (*id) = null_frame_id;
+
+ 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
+ should simply be removed. */
+ fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_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 hande
+ it locally. */
+ base = get_frame_base (next_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. */
+ base = FRAME_CHAIN (next_frame);
+
+ if (!frame_chain_valid (base, next_frame))
+ return;
+ }
+ 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). */
+ 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)
+ for (frame = get_next_frame (frame);
+ frame_relative_level (frame) >= 0;
+ frame = get_next_frame (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)
- {
- 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)
+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;
- }
/* 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). */
- else if (PC_IN_CALL_DUMMY (pc, 0, 0))
- {
- *unwind_register = dummy_frame_register_unwind;
- *unwind_pc = dummy_frame_pc_unwind;
- }
+ 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;
+ 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. */
- /* 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 && PC_IN_CALL_DUMMY (pc, 0, 0))
- /* 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->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
main. */
address = FRAME_CHAIN (next_frame);
- /* FIXME: cagney/2002-06-08: There should be two tests here.
- The first would check for a valid frame chain based on a user
- selectable policy. The default being ``stop at main'' (as
- implemented by generic_func_frame_chain_valid()). Other
- policies would be available - stop at NULL, .... The second
- test, if provided by the target architecture, would check for
- more exotic cases - most target architectures wouldn't bother
- with this second case. */
- if (!FRAME_CHAIN_VALID (address, next_frame))
+ if (!frame_chain_valid (address, next_frame))
return 0;
}
if (address == 0)
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;
prev->type = NORMAL_FRAME;
/* This change should not be needed, FIXME! We should determine
- whether any targets *need* INIT_FRAME_PC to happen after
- INIT_EXTRA_FRAME_INFO and come up with a simple way to express
- what goes on here.
+ whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
+ after INIT_EXTRA_FRAME_INFO and come up with a simple way to
+ express what goes on here.
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).
- INIT_FRAME_PC is only called from here, always after
+ DEPRECATED_INIT_FRAME_PC is only called from here, always after
INIT_EXTRA_FRAME_INFO.
The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
PC value (which hasn't been set yet). Some other machines appear
to require INIT_EXTRA_FRAME_INFO before they can do
- INIT_FRAME_PC. Phoo.
+ DEPRECATED_INIT_FRAME_PC. Phoo.
- We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
- an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
+ We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
+ complication to an already overcomplicated part of GDB.
+ gnu@cygnus.com, 15Sep92.
- Assuming that some machines need INIT_FRAME_PC after
+ Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
INIT_EXTRA_FRAME_INFO, one possible scheme:
SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
SETUP_ARBITRARY_FRAME would have to do that.
INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
- 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_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
FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
no good way to get information deduced in 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 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.
+ 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. */
FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
function does have somewhere to cache that PC value. */
- INIT_FRAME_PC_FIRST (fromleaf, prev);
+ if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
+ prev->pc = (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, prev));
if (INIT_EXTRA_FRAME_INFO_P ())
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. */
- INIT_FRAME_PC (fromleaf, prev);
+ if (DEPRECATED_INIT_FRAME_PC_P ())
+ prev->pc = 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
(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->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
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. */
- /* 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
- && PC_IN_CALL_DUMMY (prev->pc, 0, 0))
+ && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
+ ? DEPRECATED_PC_IN_CALL_DUMMY (prev->pc, 0, 0)
+ : pc_in_dummy_frame (prev->pc)))
prev->type = DUMMY_FRAME;
else
{
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)
{
return frame->pc;
}
+static int
+pc_notcurrent (struct frame_info *frame)
+{
+ /* If FRAME is not the innermost frame, that normally means that
+ FRAME->pc points at the return instruction (which is *after* the
+ call instruction), and we want to get the line containing the
+ call (because the call is where the user thinks the program is).
+ However, if the next frame is either a SIGTRAMP_FRAME or a
+ DUMMY_FRAME, then the next frame will contain a saved interrupt
+ PC and such a PC indicates the current (rather than next)
+ instruction/line, consequently, for such cases, want to get the
+ line containing fi->pc. */
+ struct frame_info *next = get_next_frame (frame);
+ int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME);
+ return notcurrent;
+}
+
+void
+find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
+{
+ (*sal) = find_pc_line (frame->pc, pc_notcurrent (frame));
+}
+
/* Per "frame.h", return the ``address'' of the frame. Code should
really be using get_frame_id(). */
CORE_ADDR
/* Find the addresses in which registers are saved in FRAME. */
void
-get_frame_saved_regs (struct frame_info *frame,
- struct frame_saved_regs *saved_regs_addr)
+deprecated_get_frame_saved_regs (struct frame_info *frame,
+ struct frame_saved_regs *saved_regs_addr)
{
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)
{
}
#endif
+struct frame_extra_info *
+get_frame_extra_info (struct frame_info *fi)
+{
+ return fi->extra_info;
+}
+
+struct frame_extra_info *
+frame_extra_info_zalloc (struct frame_info *fi, long size)
+{
+ fi->extra_info = frame_obstack_zalloc (size);
+ return fi->extra_info;
+}
+
+void
+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;
+}
+
+void
+deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
+{
+ /* See comment in "frame.h". */
+ frame->frame = base;
+}
+
+void
+deprecated_set_frame_saved_regs_hack (struct frame_info *frame,
+ CORE_ADDR *saved_regs)
+{
+ frame->saved_regs = saved_regs;
+}
+
+void
+deprecated_set_frame_extra_info_hack (struct frame_info *frame,
+ struct frame_extra_info *extra_info)
+{
+ frame->extra_info = extra_info;
+}
+
+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)
+{
+ struct frame_info *frame = XMALLOC (struct frame_info);
+ memset (frame, 0, sizeof (struct frame_info));
+ return frame;
+}
+
+struct frame_info *
+deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs,
+ long sizeof_extra_info)
+{
+ struct frame_info *frame = deprecated_frame_xmalloc ();
+ make_cleanup (xfree, frame);
+ if (sizeof_saved_regs > 0)
+ {
+ frame->saved_regs = xcalloc (1, sizeof_saved_regs);
+ make_cleanup (xfree, frame->saved_regs);
+ }
+ if (sizeof_extra_info > 0)
+ {
+ frame->extra_info = xcalloc (1, sizeof_extra_info);
+ make_cleanup (xfree, frame->extra_info);
+ }
+ return frame;
+}
+
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