/* 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 "gdb_assert.h"
#include "gdb_string.h"
#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 "frame-base.h"
+#include "command.h"
+#include "gdbcmd.h"
-/* Return a frame uniq ID that can be used to, later re-find the
+/* Flag to control debugging. */
+
+static int frame_debug;
+
+/* 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
+ if (!fi->id_p)
{
- id->base = FRAME_FP (fi);
- id->pc = fi->pc;
+ gdb_assert (!legacy_frame_p (current_gdbarch));
+ /* Find THIS frame's ID. */
+ fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->id);
+ fi->id_p = 1;
+ /* FIXME: cagney/2002-12-18: Instead of this hack, should only
+ store the frame ID in PREV_FRAME. */
+ fi->frame = fi->id.base;
}
+ return frame_id_build (fi->frame, get_frame_pc (fi));
+}
+
+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 *
/* 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))
{
- if (INNER_THAN (FRAME_FP (frame), id.base))
- /* ``inner/current < frame < id.base''. Keep looking along
- the frame chain. */
- continue;
- if (INNER_THAN (id.base, FRAME_FP (frame)))
- /* ``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 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;
}
+CORE_ADDR
+frame_pc_unwind (struct frame_info *this_frame)
+{
+ if (!this_frame->pc_unwind_cache_p)
+ {
+ CORE_ADDR pc;
+ if (gdbarch_unwind_pc_p (current_gdbarch))
+ {
+ /* The right way. The `pure' way. The one true way. This
+ method depends solely on the register-unwind code to
+ determine the value of registers in THIS frame, and hence
+ the value of this frame's PC (resume address). A typical
+ implementation is no more than:
+
+ frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
+ return extract_address (buf, size of ISA_PC_REGNUM);
+
+ Note: this method is very heavily dependent on a correct
+ register-unwind implementation, it pays to fix that
+ method first; this method is frame type agnostic, since
+ it only deals with register values, it works with any
+ frame. This is all in stark contrast to the old
+ FRAME_SAVED_PC which would try to directly handle all the
+ different ways that a PC could be unwound. */
+ pc = gdbarch_unwind_pc (current_gdbarch, this_frame);
+ }
+ else if (this_frame->level < 0)
+ {
+ /* FIXME: cagney/2003-03-06: Old code and and a sentinel
+ frame. Do like was always done. Fetch the PC's value
+ direct from the global registers array (via read_pc).
+ This assumes that this frame belongs to the current
+ global register cache. The assumption is dangerous. */
+ pc = read_pc ();
+ }
+ else if (DEPRECATED_FRAME_SAVED_PC_P ())
+ {
+ /* FIXME: cagney/2003-03-06: Old code, but not a sentinel
+ frame. Do like was always done. Note that this method,
+ unlike unwind_pc(), tries to handle all the different
+ frame cases directly. It fails. */
+ pc = DEPRECATED_FRAME_SAVED_PC (this_frame);
+ }
+ else
+ internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method");
+ this_frame->pc_unwind_cache = pc;
+ this_frame->pc_unwind_cache_p = 1;
+ }
+ return this_frame->pc_unwind_cache;
+}
+
+CORE_ADDR
+frame_func_unwind (struct frame_info *fi)
+{
+ if (!fi->prev_func.p)
+ {
+ fi->prev_func.p = 1;
+ fi->prev_func.addr = get_pc_function_start (frame_pc_unwind (fi));
+ }
+ return fi->prev_func.addr;
+}
+
+CORE_ADDR
+get_frame_func (struct frame_info *fi)
+{
+ return frame_func_unwind (fi->next);
+}
+
+static int
+do_frame_unwind_register (void *src, int regnum, void *buf)
+{
+ frame_unwind_register (src, regnum, buf);
+ return 1;
+}
+
+void
+frame_pop (struct frame_info *this_frame)
+{
+ struct regcache *scratch_regcache;
+ struct cleanup *cleanups;
+
+ if (DEPRECATED_POP_FRAME_P ())
+ {
+ /* A legacy architecture that has implemented a custom pop
+ function. All new architectures should instead be using the
+ generic code below. */
+ DEPRECATED_POP_FRAME;
+ }
+ else
+ {
+ /* Make a copy of all the register values unwound from this
+ frame. Save them in a scratch buffer so that there isn't a
+ race betweening trying to extract the old values from the
+ current_regcache while, at the same time writing new values
+ into that same cache. */
+ struct regcache *scratch = regcache_xmalloc (current_gdbarch);
+ struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch);
+ regcache_save (scratch, do_frame_unwind_register, this_frame);
+ /* FIXME: cagney/2003-03-16: It should be possible to tell the
+ target's register cache that it is about to be hit with a
+ burst register transfer and that the sequence of register
+ writes should be batched. The pair target_prepare_to_store()
+ and target_store_registers() kind of suggest this
+ functionality. Unfortunatly, they don't implement it. Their
+ lack of a formal definition can lead to targets writing back
+ bogus values (arguably a bug in the target code mind). */
+ /* Now copy those saved registers into the current regcache.
+ Here, regcache_cpy() calls regcache_restore(). */
+ regcache_cpy (current_regcache, scratch);
+ do_cleanups (cleanups);
+ }
+ /* We've made right mess of GDB's local state, just discard
+ everything. */
+ flush_cached_frames ();
+}
+
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. */
+ /* 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. See comment in
+ "frame-unwind.h" for why NEXT frame and this unwind cace are
+ passed in. */
+ frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
+ optimizedp, lvalp, addrp, realnump, bufferp);
- if (frame == NULL)
+}
+
+void
+frame_register (struct frame_info *frame, int regnum,
+ int *optimizedp, enum lval_type *lvalp,
+ CORE_ADDR *addrp, int *realnump, void *bufferp)
+{
+ /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
+ that the value proper does not need to be fetched. */
+ gdb_assert (optimizedp != NULL);
+ gdb_assert (lvalp != NULL);
+ gdb_assert (addrp != NULL);
+ gdb_assert (realnump != NULL);
+ /* gdb_assert (bufferp != NULL); */
+
+ /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
+ of the register in the register cache. It should instead return
+ the REGNUM corresponding to that register. Translate the . */
+ if (DEPRECATED_GET_SAVED_REGISTER_P ())
{
- /* 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);
+ DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame,
+ regnum, lvalp);
+ /* Compute the REALNUM if the caller wants it. */
+ if (*lvalp == lval_register)
+ {
+ int regnum;
+ for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++)
+ {
+ if (*addrp == register_offset_hack (current_gdbarch, regnum))
+ {
+ *realnump = regnum;
+ return;
+ }
+ }
+ internal_error (__FILE__, __LINE__,
+ "Failed to compute the register number corresponding"
+ " to 0x%s", paddr_d (*addrp));
+ }
+ *realnump = -1;
return;
}
- /* Ask this frame to unwind its register. */
- frame->register_unwind (frame, &frame->register_unwind_cache, 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
-frame_unwind_signed_register (struct frame_info *frame, int regnum,
- LONGEST *val)
+frame_unwind_register (struct frame_info *frame, int regnum, void *buf)
{
int optimized;
CORE_ADDR addr;
int realnum;
enum lval_type lval;
- void *buf = alloca (MAX_REGISTER_RAW_SIZE);
frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
&realnum, buf);
+}
+
+void
+frame_unwind_signed_register (struct frame_info *frame, int regnum,
+ LONGEST *val)
+{
+ void *buf = alloca (MAX_REGISTER_RAW_SIZE);
+ frame_unwind_register (frame, regnum, buf);
(*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum));
}
frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
ULONGEST *val)
{
- int optimized;
- CORE_ADDR addr;
- int realnum;
- enum lval_type lval;
void *buf = alloca (MAX_REGISTER_RAW_SIZE);
- frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
- &realnum, buf);
+ frame_unwind_register (frame, regnum, buf);
(*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum));
}
+void
+frame_read_register (struct frame_info *frame, int regnum, void *buf)
+{
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_unwind_register (frame->next, regnum, buf);
+}
+
void
frame_read_unsigned_register (struct frame_info *frame, int regnum,
ULONGEST *val)
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);
}
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);
-}
-
-void
-get_saved_register (char *raw_buffer,
- int *optimized,
- CORE_ADDR *addrp,
- struct frame_info *frame,
- int regnum,
- enum lval_type *lval)
-{
- GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval);
+ gdb_assert (frame != NULL && frame->next != NULL);
+ frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
+ &realnumx, raw_buffer);
}
/* frame_register_read ()
int
frame_register_read (struct frame_info *frame, int regnum, void *myaddr)
{
- int optim;
- get_saved_register (myaddr, &optim, (CORE_ADDR *) NULL, frame,
- regnum, (enum lval_type *) NULL);
+ int optimized;
+ enum lval_type lval;
+ CORE_ADDR addr;
+ int realnum;
+ frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
/* FIXME: cagney/2002-05-15: This test, is just bogus.
if (register_cached (regnum) < 0)
return 0; /* register value not available */
- return !optim;
+ return !optimized;
}
{
int i;
+ if (len < 0)
+ len = strlen (name);
+
/* Search register name space. */
for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++)
if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))
return REGISTER_NAME (regnum);
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->prologue_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? */
+ /* FIXME: cagney/2003-04-04: Once ->pc is eliminated, this
+ assignment can go away. */
+ frame->pc = frame_pc_unwind (frame);
+ /* Make the sentinel frame's ID valid, but invalid. That way all
+ comparisons with it should fail. */
+ frame->id_p = 1;
+ frame->id = null_frame_id;
+ return frame;
+}
+
+/* Info about the innermost stack frame (contents of FP register) */
+
+static struct frame_info *current_frame;
+
+/* Cache for frame addresses already read by gdb. Valid only while
+ inferior is stopped. Control variables for the frame cache should
+ be local to this module. */
+
+static struct obstack frame_cache_obstack;
+
+void *
+frame_obstack_zalloc (unsigned long 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_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. */
+
+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)
+{
+ /* First check, and report, the lack of registers. Having GDB
+ report "No stack!" or "No memory" when the target doesn't even
+ have registers is very confusing. Besides, "printcmd.exp"
+ explicitly checks that ``print $pc'' with no registers prints "No
+ registers". */
+ if (!target_has_registers)
+ error ("No registers.");
+ if (!target_has_stack)
+ error ("No stack.");
+ if (!target_has_memory)
+ error ("No memory.");
+ if (current_frame == NULL)
+ {
+ 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
+select_frame (struct frame_info *fi)
+{
+ 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 (get_frame_pc (fi));
+ 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.
+ If the value isn't here AND a value is needed, try the next inner
+ most frame. */
+
+static void
+legacy_saved_regs_prev_register (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ int regnum, int *optimizedp,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnump, void *bufferp)
+{
+ /* HACK: New code is passed the next frame and this cache.
+ Unfortunatly, old code expects this frame. Since this is a
+ backward compatibility hack, cheat by walking one level along the
+ prologue chain to the frame the old code expects.
+
+ Do not try this at home. Professional driver, closed course. */
+ struct frame_info *frame = next_frame->prev;
+ gdb_assert (frame != NULL);
+
+ /* Only (older) architectures that implement the
+ DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this
+ function. */
+ gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
+
+ /* Load the saved_regs register cache. */
+ if (get_frame_saved_regs (frame) == NULL)
+ DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
+
+ if (get_frame_saved_regs (frame) != NULL
+ && get_frame_saved_regs (frame)[regnum] != 0)
+ {
+ if (regnum == SP_REGNUM)
+ {
+ /* SP register treated specially. */
+ *optimizedp = 0;
+ *lvalp = not_lval;
+ *addrp = 0;
+ *realnump = -1;
+ if (bufferp != NULL)
+ store_address (bufferp, REGISTER_RAW_SIZE (regnum),
+ get_frame_saved_regs (frame)[regnum]);
+ }
+ else
+ {
+ /* Any other register is saved in memory, fetch it but cache
+ a local copy of its value. */
+ *optimizedp = 0;
+ *lvalp = lval_memory;
+ *addrp = get_frame_saved_regs (frame)[regnum];
+ *realnump = -1;
+ if (bufferp != NULL)
+ {
+#if 1
+ /* Save each register value, as it is read in, in a
+ frame based cache. */
+ void **regs = (*this_prologue_cache);
+ if (regs == NULL)
+ {
+ int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
+ * sizeof (void *));
+ regs = frame_obstack_zalloc (sizeof_cache);
+ (*this_prologue_cache) = regs;
+ }
+ if (regs[regnum] == NULL)
+ {
+ regs[regnum]
+ = frame_obstack_zalloc (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 (get_frame_saved_regs (frame)[regnum], bufferp,
+ REGISTER_RAW_SIZE (regnum));
+#endif
+ }
+ }
+ return;
+ }
+
+ /* No luck. Assume this and the next frame have the same register
+ value. Pass the unwind request down the frame chain to the next
+ frame. Hopefully that frame will find the register's location. */
+ frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp,
+ realnump, bufferp);
+}
+
+static void
+legacy_saved_regs_this_id (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ struct frame_id *id)
+{
+ int fromleaf;
+ CORE_ADDR base;
+ CORE_ADDR pc;
+
+ if (frame_relative_level (next_frame) < 0)
+ {
+ /* FIXME: cagney/2003-03-14: We've got the extra special case of
+ unwinding a sentinel frame, the PC of which is pointing at a
+ stack dummy. Fake up the dummy frame's ID using the same
+ sequence as is found a traditional unwinder. */
+ (*id) = frame_id_build (read_fp (), read_pc ());
+ return;
+ }
+
+ /* 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. */
+ gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
+ base = DEPRECATED_FRAME_CHAIN (next_frame);
+
+ if (!legacy_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) = frame_id_build (base, pc);
+}
+
+const struct frame_unwind legacy_saved_regs_unwinder = {
+ /* Not really. It gets overridden by legacy_get_prev_frame. */
+ UNKNOWN_FRAME,
+ legacy_saved_regs_this_id,
+ legacy_saved_regs_prev_register
+};
+const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder;
+
+
+/* Function: deprecated_generic_get_saved_register
+ Find register number REGNUM relative to FRAME and put its (raw,
+ target format) contents in *RAW_BUFFER.
+
+ Set *OPTIMIZED if the variable was optimized out (and thus can't be
+ fetched). Note that this is never set to anything other than zero
+ in this implementation.
+
+ Set *LVAL to lval_memory, lval_register, or not_lval, depending on
+ whether the value was fetched from memory, from a register, or in a
+ strange and non-modifiable way (e.g. a frame pointer which was
+ calculated rather than fetched). We will use not_lval for values
+ fetched from generic dummy frames.
+
+ Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
+ offset into the registers array. If the value is stored in a dummy
+ frame, set *ADDRP to zero.
+
+ The argument RAW_BUFFER must point to aligned memory. */
+
+void
+deprecated_generic_get_saved_register (char *raw_buffer, int *optimized,
+ CORE_ADDR *addrp,
+ struct frame_info *frame, int regnum,
+ enum lval_type *lval)
+{
+ if (!target_has_registers)
+ error ("No registers.");
+
+ gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
+
+ /* Normal systems don't optimize out things with register numbers. */
+ if (optimized != NULL)
+ *optimized = 0;
+
+ if (addrp) /* default assumption: not found in memory */
+ *addrp = 0;
+
+ /* Note: since the current frame's registers could only have been
+ saved by frames INTERIOR TO the current frame, we skip examining
+ the current frame itself: otherwise, we would be getting the
+ previous frame's registers which were saved by the current frame. */
+
+ if (frame != NULL)
+ {
+ for (frame = get_next_frame (frame);
+ frame_relative_level (frame) >= 0;
+ frame = get_next_frame (frame))
+ {
+ 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 (get_frame_pc (frame),
+ get_frame_base (frame)),
+ regnum, raw_buffer);
+ return;
+ }
+
+ DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
+ if (get_frame_saved_regs (frame) != NULL
+ && get_frame_saved_regs (frame)[regnum] != 0)
+ {
+ 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;
+ }
+ }
+ }
+
+ /* If we get thru the loop to this point, it means the register was
+ not saved in any frame. Return the actual live-register value. */
+
+ if (lval) /* found it in a live register */
+ *lval = lval_register;
+ if (addrp)
+ *addrp = REGISTER_BYTE (regnum);
+ if (raw_buffer)
+ deprecated_read_register_gen (regnum, raw_buffer);
+}
+
+/* Determine the frame's type based on its PC. */
+
+static enum frame_type
+frame_type_from_pc (CORE_ADDR pc)
+{
+ /* 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
+ {
+ char *name;
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (PC_IN_SIGTRAMP (pc, name))
+ return SIGTRAMP_FRAME;
+ else
+ return NORMAL_FRAME;
+ }
+}
+
+/* Create an arbitrary (i.e. address specified by user) or innermost frame.
+ Always returns a non-NULL value. */
+
+struct frame_info *
+create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
+{
+ struct frame_info *fi;
+
+ fi = frame_obstack_zalloc (sizeof (struct frame_info));
+
+ fi->next = create_sentinel_frame (current_regcache);
+
+ /* Select/initialize both the unwind function and the frame's type
+ based on the PC. */
+ fi->unwind = frame_unwind_find_by_pc (current_gdbarch, fi->pc);
+ if (fi->unwind->type != UNKNOWN_FRAME)
+ fi->type = fi->unwind->type;
+ else
+ fi->type = frame_type_from_pc (pc);
+
+ deprecated_update_frame_base_hack (fi, addr);
+ deprecated_update_frame_pc_hack (fi, pc);
+
+ if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
+ DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi);
+
+ return fi;
+}
+
+/* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
+ innermost 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 *this_frame)
+{
+ if (this_frame->level > 0)
+ return this_frame->next;
+ else
+ return NULL;
+}
+
+/* Flush the entire frame cache. */
+
+void
+flush_cached_frames (void)
+{
+ /* Since we can't really be sure what the first object allocated was */
+ obstack_free (&frame_cache_obstack, 0);
+ obstack_init (&frame_cache_obstack);
+
+ current_frame = NULL; /* Invalidate cache */
+ select_frame (NULL);
+ annotate_frames_invalid ();
+}
+
+/* Flush the frame cache, and start a new one if necessary. */
+
+void
+reinit_frame_cache (void)
+{
+ flush_cached_frames ();
+
+ /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
+ if (PIDGET (inferior_ptid) != 0)
+ {
+ select_frame (get_current_frame ());
+ }
+}
+
+/* Create the previous frame using the deprecated methods
+ INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
+
+static struct frame_info *
+legacy_get_prev_frame (struct frame_info *this_frame)
+{
+ CORE_ADDR address = 0;
+ struct frame_info *prev;
+ int fromleaf;
+
+ /* Allocate the new frame.
+
+ There is no reason to worry about memory leaks, should the
+ remainder of the function fail. The allocated memory will be
+ quickly reclaimed when the frame cache is flushed, and the `we've
+ been here before' check, in get_prev_frame will stop repeated
+ memory allocation calls. */
+ prev = FRAME_OBSTACK_ZALLOC (struct frame_info);
+ prev->level = this_frame->level + 1;
+
+ /* Do not completly wire it in to the frame chain. Some (bad) code
+ in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull
+ some fancy tricks (of course such code is, by definition,
+ recursive).
+
+ On the other hand, methods, such as get_frame_pc() and
+ get_frame_base() rely on being able to walk along the frame
+ chain. Make certain that at least they work by providing that
+ link. Of course things manipulating prev can't go back. */
+ prev->next = this_frame;
+
+ /* NOTE: cagney/2002-11-18: Should have been correctly setting the
+ frame's type here, before anything else, and not last, at the
+ bottom of this function. The various
+ DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
+ DEPRECATED_INIT_FRAME_PC_FIRST and
+ DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
+ that handle the frame not being correctly set from the start.
+ Unfortunatly those same work-arounds rely on the type defaulting
+ to NORMAL_FRAME. Ulgh! The new frame code does not have this
+ problem. */
+ prev->type = UNKNOWN_FRAME;
+
+ /* A legacy frame's ID is always computed here. Mark it as valid. */
+ prev->id_p = 1;
+
+ /* Handle sentinel frame unwind as a special case. */
+ if (this_frame->level < 0)
+ {
+ /* Try to unwind the PC. If that doesn't work, assume we've reached
+ the oldest frame and simply return. Is there a better sentinal
+ value? The unwound PC value is then used to initialize the new
+ previous frame's type.
+
+ Note that the pc-unwind is intentionally performed before the
+ frame chain. This is ok since, for old targets, both
+ frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
+ DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
+ have already been initialized (using
+ DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
+ doesn't matter.
+
+ By unwinding the PC first, it becomes possible to, in the case of
+ a dummy frame, avoid also unwinding the frame ID. This is
+ because (well ignoring the PPC) a dummy frame can be located
+ using THIS_FRAME's frame ID. */
+
+ deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame));
+ if (get_frame_pc (prev) == 0)
+ {
+ /* The allocated PREV_FRAME will be reclaimed when the frame
+ obstack is next purged. */
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - unwound PC zero\n");
+ return NULL;
+ }
+
+ /* Set the unwind functions based on that identified PC. Ditto
+ for the "type" but strongly prefer the unwinder's frame type. */
+ prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc);
+ if (prev->unwind->type == UNKNOWN_FRAME)
+ prev->type = frame_type_from_pc (prev->pc);
+ else
+ prev->type = prev->unwind->type;
+
+ /* Find the prev's frame's ID. */
+ if (prev->type == DUMMY_FRAME
+ && gdbarch_unwind_dummy_id_p (current_gdbarch))
+ {
+ /* When unwinding a normal frame, the stack structure is
+ determined by analyzing the frame's function's code (be
+ it using brute force prologue analysis, or the dwarf2
+ CFI). In the case of a dummy frame, that simply isn't
+ possible. The The PC is either the program entry point,
+ or some random address on the stack. Trying to use that
+ PC to apply standard frame ID unwind techniques is just
+ asking for trouble. */
+ /* Assume call_function_by_hand(), via SAVE_DUMMY_FRAME_TOS,
+ previously saved the dummy frame's ID. Things only work
+ if the two return the same value. */
+ gdb_assert (SAVE_DUMMY_FRAME_TOS_P ());
+ /* Use an architecture specific method to extract the prev's
+ dummy ID from the next frame. Note that this method uses
+ frame_register_unwind to obtain the register values
+ needed to determine the dummy frame's ID. */
+ prev->id = gdbarch_unwind_dummy_id (current_gdbarch, this_frame);
+ }
+ else
+ {
+ /* We're unwinding a sentinel frame, the PC of which is
+ pointing at a stack dummy. Fake up the dummy frame's ID
+ using the same sequence as is found a traditional
+ unwinder. Once all architectures supply the
+ unwind_dummy_id method, this code can go away. */
+ prev->id = frame_id_build (read_fp (), read_pc ());
+ }
+
+ /* Check that the unwound ID is valid. */
+ if (!frame_id_p (prev->id))
+ {
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost legacy sentinel frame - unwound frame ID invalid\n");
+ return NULL;
+ }
+
+ /* Check that the new frame isn't inner to (younger, below,
+ next) the old frame. If that happens the frame unwind is
+ going backwards. */
+ /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
+ that doesn't have a valid frame ID. Should instead set the
+ sentinel frame's frame ID to a `sentinel'. Leave it until
+ after the switch to storing the frame ID, instead of the
+ frame base, in the frame object. */
+
+ /* FIXME: cagney/2002-12-18: Instead of this hack, should only
+ store the frame ID in PREV_FRAME. */
+ /* FIXME: cagney/2003-04-04: Once ->frame is eliminated, this
+ assignment can go. */
+ prev->frame = prev->id.base;
+
+ /* Link it in. */
+ this_frame->prev = prev;
+
+ /* FIXME: cagney/2002-01-19: This call will go away. Instead of
+ initializing extra info, all frames will use the frame_cache
+ (passed to the unwind functions) to store additional frame
+ info. 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 DEPRECATED_INIT_EXTRA_FRAME_INFO to
+ initialize the inner-most frame. */
+ if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
+ {
+ DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev);
+ }
+ return prev;
+ }
+
+ /* This code only works on normal frames. A sentinel frame, where
+ the level is -1, should never reach this code. */
+ gdb_assert (this_frame->level >= 0);
+
+ /* On some machines it is possible to call a function without
+ setting up a stack frame for it. On these machines, we
+ define this macro to take two args; a frameinfo pointer
+ identifying a frame and a variable to set or clear if it is
+ or isn't leafless. */
+
+ /* Still don't want to worry about this except on the innermost
+ frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
+ function invocation. */
+ if (this_frame->level == 0)
+ /* FIXME: 2002-11-09: Frameless functions can 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 (this_frame);
+ else
+ fromleaf = 0;
+
+ if (fromleaf)
+ /* A frameless inner-most frame. The `FP' (which isn't an
+ architecture frame-pointer register!) of the caller is the same
+ as the callee. */
+ /* FIXME: 2002-11-09: There isn't any reason to special case this
+ edge condition. Instead the per-architecture code should hande
+ it locally. */
+ address = get_frame_base (this_frame);
+ else
+ {
+ /* Two macros defined in tm.h specify the machine-dependent
+ actions to be performed here.
+
+ First, get the frame's chain-pointer.
+
+ If that is zero, the frame is the outermost frame or a leaf
+ called by the outermost frame. This means that if start
+ calls main without a frame, we'll return 0 (which is fine
+ anyway).
+
+ Nope; there's a problem. This also returns when the current
+ routine is a leaf of main. This is unacceptable. We move
+ this to after the ffi test; I'd rather have backtraces from
+ start go curfluy than have an abort called from main not show
+ main. */
+ gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
+ address = DEPRECATED_FRAME_CHAIN (this_frame);
+
+ if (!legacy_frame_chain_valid (address, this_frame))
+ return 0;
+ }
+ if (address == 0)
+ return 0;
+
+ /* Link in the already allocated prev frame. */
+ this_frame->prev = prev;
+ deprecated_update_frame_base_hack (prev, address);
+
+ /* This change should not be needed, FIXME! We should determine
+ whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
+ after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
+ way to express what goes on here.
+
+ DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
+ create_new_frame (where the PC is already set up) and here (where
+ it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
+ always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
+
+ The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
+ requires the PC value (which hasn't been set yet). Some other
+ machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
+ before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
+
+ 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 DEPRECATED_INIT_FRAME_PC after
+ DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
+
+ SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
+ (read_fp ()), read_pc ()). Machines with extra frame info would
+ do that (or the local equivalent) and then set the extra fields.
+
+ SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
+ create_new_frame would no longer init extra frame info;
+ SETUP_ARBITRARY_FRAME would have to do that.
+
+ INIT_PREV_FRAME(fromleaf, prev) Replace
+ DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
+ This should also return a flag saying whether to keep the new
+ frame, or whether to discard it, because on some machines (e.g.
+ mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
+ called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
+ way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
+ into the extra fields of the new frame). std_frame_pc(fromleaf,
+ prev)
+
+ This is the default setting for INIT_PREV_FRAME. It just does
+ what the default DEPRECATED_INIT_FRAME_PC does. Some machines
+ will call it from INIT_PREV_FRAME (either at the beginning, the
+ end, or in the middle). Some machines won't use it.
+
+ kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
+
+ /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
+ reason for things to be this complicated.
+
+ The trick is to assume that there is always a frame. Instead of
+ special casing the inner-most frame, create fake frame
+ (containing the hardware registers) that is inner to the
+ user-visible inner-most frame (...) and then unwind from that.
+ That way architecture code can use use the standard
+ frame_XX_unwind() functions and not differentiate between the
+ inner most and any other case.
+
+ Since there is always a frame to unwind from, there is always
+ somewhere (THIS_FRAME) to store all the info needed to construct
+ a new (previous) frame without having to first create it. This
+ means that the convolution below - needing to carefully order a
+ frame's initialization - isn't needed.
+
+ The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
+ for a more up-to-date architecture, always calls
+ FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
+ without first needing the frame! Instead of the convolution
+ below, we could have simply called FRAME_SAVED_PC() and been done
+ with it! Note that FRAME_SAVED_PC() is being superseed by
+ frame_pc_unwind() and that function does have somewhere to cache
+ that PC value. */
+
+ if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
+ deprecated_update_frame_pc_hack (prev,
+ DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf,
+ prev));
+
+ if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
+ DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev);
+
+ /* This entry is in the frame queue now, which is good since
+ FRAME_SAVED_PC may use that queue to figure out its value (see
+ tm-sparc.h). We want the pc saved in the inferior frame. */
+ if (DEPRECATED_INIT_FRAME_PC_P ())
+ deprecated_update_frame_pc_hack (prev,
+ DEPRECATED_INIT_FRAME_PC (fromleaf,
+ prev));
+
+ /* If ->frame and ->pc are unchanged, we are in the process of
+ getting ourselves into an infinite backtrace. Some architectures
+ check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
+ like there is no reason this can't be an architecture-independent
+ check. */
+ if (get_frame_base (prev) == get_frame_base (this_frame)
+ && get_frame_pc (prev) == get_frame_pc (this_frame))
+ {
+ this_frame->prev = NULL;
+ obstack_free (&frame_cache_obstack, prev);
+ return NULL;
+ }
+
+ /* Initialize the code used to unwind the frame PREV based on the PC
+ (and probably other architectural information). The PC lets you
+ check things like the debug info at that point (dwarf2cfi?) and
+ use that to decide how the frame should be unwound. */
+ prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (prev));
+
+ /* If the unwinder provides a frame type, use it. Otherwize
+ continue on to that heuristic mess. */
+ if (prev->unwind->type != UNKNOWN_FRAME)
+ {
+ prev->type = prev->unwind->type;
+ return prev;
+ }
+
+ /* 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 (get_frame_pc (prev), 0, 0)
+ : pc_in_dummy_frame (get_frame_pc (prev))))
+ prev->type = DUMMY_FRAME;
+ else
+ {
+ /* FIXME: cagney/2002-11-10: This should be moved to before the
+ INIT code above so that the INIT code knows what the frame's
+ type is (in fact, for a [generic] dummy-frame, the type can
+ be set and then the entire initialization can be skipped.
+ Unforunatly, its the INIT code that sets the PC (Hmm, catch
+ 22). */
+ char *name;
+ find_pc_partial_function (get_frame_pc (prev), &name, NULL, NULL);
+ if (PC_IN_SIGTRAMP (get_frame_pc (prev), name))
+ prev->type = SIGTRAMP_FRAME;
+ /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
+ architectures are forcing the frame's type in INIT so we
+ don't want to override it here. Remember, NORMAL_FRAME == 0,
+ so it all works (just :-/). Once this initialization is
+ moved to the start of this function, all this nastness will
+ go away. */
+ }
+
+ return prev;
+}
+
+/* Return a structure containing various interesting information
+ about the frame that called THIS_FRAME. Returns NULL
+ if there is no such frame. */
+
+struct frame_info *
+get_prev_frame (struct frame_info *this_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 (this_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
+ THIS_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 (this_frame != NULL);
+
+ if (this_frame->level >= 0
+ && !backtrace_below_main
+ && inside_main_func (get_frame_pc (this_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. */
+ {
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - inside main func.\n");
+ return NULL;
+ }
+
+ /* Only try to do the unwind once. */
+ if (this_frame->prev_p)
+ return this_frame->prev;
+ this_frame->prev_p = 1;
+
+#if 0
+ /* If we're inside the entry file, it isn't valid. Don't apply this
+ test to a dummy frame - dummy frame PC's typically land in the
+ entry file. Don't apply this test to the sentinel frame.
+ Sentinel frames should always be allowed to unwind. */
+ /* 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. */
+ /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call to
+ inside_entry_file destroys a meaningful backtrace under some
+ conditions. E. g. the backtrace tests in the asm-source testcase
+ are broken for some targets. In this test the functions are all
+ implemented as part of one file and the testcase is not necessarily
+ linked with a start file (depending on the target). What happens is,
+ that the first frame is printed normaly and following frames are
+ treated as being inside the enttry file then. This way, only the
+ #0 frame is printed in the backtrace output. */
+ if (this_frame->type != DUMMY_FRAME && this_frame->level >= 0
+ && inside_entry_file (get_frame_pc (this_frame)))
+ {
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - inside entry file\n");
+ return NULL;
+ }
+#endif
+
+ /* If we're already inside the entry function for the main objfile,
+ then it isn't valid. Don't apply this test to a dummy frame -
+ dummy frame PC's typically land in the entry func. Don't apply
+ this test to the sentinel frame. Sentinel frames should always
+ be allowed to unwind. */
+ /* NOTE: cagney/2003-02-25: Don't enable until someone has found
+ hard evidence that this is needed. */
+ if (0
+ && this_frame->type != DUMMY_FRAME && this_frame->level >= 0
+ && inside_entry_func (get_frame_pc (this_frame)))
+ {
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - inside entry func\n");
+ return NULL;
+ }
+
+ /* If any of the old frame initialization methods are around, use
+ the legacy get_prev_frame method. */
+ if (legacy_frame_p (current_gdbarch))
+ {
+ prev_frame = legacy_get_prev_frame (this_frame);
+ if (frame_debug && prev_frame == NULL)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - legacy_get_prev_frame NULL.\n");
+ return prev_frame;
+ }
+
+ /* Check that this frame's ID was valid. If it wasn't, don't try to
+ unwind to the prev frame. Be careful to not apply this test to
+ the sentinel frame. */
+ if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame)))
+ {
+ if (frame_debug)
+ fprintf_filtered (gdb_stdlog,
+ "Outermost frame - this ID is NULL\n");
+ return NULL;
+ }
+
+ /* Check that this frame's ID isn't inner to (younger, below, next)
+ the next frame. This happens when frame unwind goes backwards.
+ Since the sentinel frame isn't valid, don't apply this if this
+ frame is entier the inner-most or sentinel frame. */
+ if (this_frame->level > 0
+ && frame_id_inner (get_frame_id (this_frame),
+ get_frame_id (this_frame->next)))
+ error ("This frame inner-to next frame (corrupt stack?)");
+
+ /* Check that this and the next frame are different. If they are
+ not, there is most likely a stack cycle. As with the inner-than
+ test, avoid the inner-most and sentinel frames. */
+ /* FIXME: cagney/2003-03-17: Can't yet enable this this check. The
+ frame_id_eq() method doesn't yet use function addresses when
+ comparing frame IDs. */
+ if (0
+ && this_frame->level > 0
+ && frame_id_eq (get_frame_id (this_frame),
+ get_frame_id (this_frame->next)))
+ error ("This frame identical to next frame (corrupt stack?)");
+
+ /* 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 = this_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
+ DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
+ have already been initialized (using
+ DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
+ doesn't matter.
+
+ By unwinding the PC first, it becomes possible to, in the case of
+ a dummy frame, avoid also unwinding the frame ID. This is
+ because (well ignoring the PPC) a dummy frame can be located
+ using THIS_FRAME's frame ID. */
+
+ /* FIXME: cagney/2003-04-04: Once ->pc is eliminated, this
+ assignment can go away. */
+ prev_frame->pc = frame_pc_unwind (this_frame);
+ if (prev_frame->pc == 0)
+ {
+ /* The allocated PREV_FRAME will be reclaimed when the frame
+ obstack is next purged. */
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Outermost frame - unwound PC zero\n");
+ return NULL;
+ }
+
+ /* Set the unwind functions based on that identified PC. */
+ prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ prev_frame->pc);
+
+ /* FIXME: cagney/2003-04-02: Rather than storing the frame's type in
+ the frame, the unwinder's type should be returned directly.
+ Unfortunatly, legacy code, called by legacy_get_prev_frame,
+ explicitly set the frames type using the method
+ deprecated_set_frame_type(). */
+ gdb_assert (prev_frame->unwind->type != UNKNOWN_FRAME);
+ prev_frame->type = prev_frame->unwind->type;
+
+ /* Can the frame's type and unwinder be computed on demand? That
+ would make a frame's creation really really lite! */
+
+ /* The prev's frame's ID is computed by demand in get_frame_id(). */
+
+ /* The unwound frame ID is validate at the start of this function,
+ as part of the logic to decide if that frame should be further
+ unwound, and not here while the prev frame is being created.
+ Doing this makes it possible for the user to examine a frame that
+ has an invalid frame ID.
+
+ The very old VAX frame_args_address_correct() method noted: [...]
+ For the sake of argument, suppose that the stack is somewhat
+ trashed (which is one reason that "info frame" exists). So,
+ return 0 (indicating we don't know the address of the arglist) if
+ we don't know what frame this frame calls. */
+
+ /* Link it in. */
+ this_frame->prev = prev_frame;
+ prev_frame->next = this_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 (get_frame_pc (frame), pc_notcurrent (frame));
+}
+
+/* Per "frame.h", return the ``address'' of the frame. Code should
+ really be using get_frame_id(). */
+CORE_ADDR
+get_frame_base (struct frame_info *fi)
+{
+ if (!fi->id_p)
+ {
+ /* HACK: Force the ID code to (indirectly) initialize the
+ ->frame pointer. */
+ get_frame_id (fi);
+ }
+ return fi->frame;
+}
+
+/* High-level offsets into the frame. Used by the debug info. */
+
+CORE_ADDR
+get_frame_base_address (struct frame_info *fi)
+{
+ if (get_frame_type (fi) != NORMAL_FRAME)
+ return 0;
+ if (fi->base == NULL)
+ fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ /* Sneaky: If the low-level unwind and high-level base code share a
+ common unwinder, let them share the prologue cache. */
+ if (fi->base->unwind == fi->unwind)
+ return fi->base->this_base (fi->next, &fi->prologue_cache);
+ return fi->base->this_base (fi->next, &fi->base_cache);
+}
+
+CORE_ADDR
+get_frame_locals_address (struct frame_info *fi)
+{
+ void **cache;
+ if (get_frame_type (fi) != NORMAL_FRAME)
+ return 0;
+ /* If there isn't a frame address method, find it. */
+ if (fi->base == NULL)
+ fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ /* Sneaky: If the low-level unwind and high-level base code share a
+ common unwinder, let them share the prologue cache. */
+ if (fi->base->unwind == fi->unwind)
+ cache = &fi->prologue_cache;
+ else
+ cache = &fi->base_cache;
+ return fi->base->this_locals (fi->next, cache);
+}
+
+CORE_ADDR
+get_frame_args_address (struct frame_info *fi)
+{
+ void **cache;
+ if (get_frame_type (fi) != NORMAL_FRAME)
+ return 0;
+ /* If there isn't a frame address method, find it. */
+ if (fi->base == NULL)
+ fi->base = frame_base_find_by_pc (current_gdbarch, get_frame_pc (fi));
+ /* Sneaky: If the low-level unwind and high-level base code share a
+ common unwinder, let them share the prologue cache. */
+ if (fi->base->unwind == fi->unwind)
+ cache = &fi->prologue_cache;
+ else
+ cache = &fi->base_cache;
+ return fi->base->this_args (fi->next, cache);
+}
+
+/* Level of the selected frame: 0 for innermost, 1 for its caller, ...
+ or -1 for a NULL frame. */
+
+int
+frame_relative_level (struct frame_info *fi)
+{
+ if (fi == NULL)
+ return -1;
+ else
+ return fi->level;
+}
+
+enum frame_type
+get_frame_type (struct frame_info *frame)
+{
+ /* Some targets still don't use [generic] dummy frames. Catch them
+ here. */
+ if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
+ && deprecated_frame_in_dummy (frame))
+ return DUMMY_FRAME;
+ if (frame->type == UNKNOWN_FRAME)
+ return NORMAL_FRAME;
+ else
+ return frame->type;
+}
+
+void
+deprecated_set_frame_type (struct frame_info *frame, enum frame_type type)
+{
+ /* Arrrg! See comment in "frame.h". */
+ frame->type = type;
+}
+
+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". */
+ frame->pc = pc;
+ /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
+ maintaining a locally allocated frame object. Since such frame's
+ are not in the frame chain, it isn't possible to assume that the
+ frame has a next. Sigh. */
+ if (frame->next != NULL)
+ {
+ /* While we're at it, update this frame's cached PC value, found
+ in the next frame. Oh for the day when "struct frame_info"
+ is opaque and this hack on hack can just go away. */
+ frame->next->pc_unwind_cache = pc;
+ frame->next->pc_unwind_cache_p = 1;
+ }
+}
+
+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;
+}
+
+int
+legacy_frame_p (struct gdbarch *current_gdbarch)
+{
+ return (DEPRECATED_INIT_FRAME_PC_P ()
+ || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
+ || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
+ || DEPRECATED_FRAME_CHAIN_P ()
+ || !gdbarch_unwind_dummy_id_p (current_gdbarch)
+ || !SAVE_DUMMY_FRAME_TOS_P ());
+}
+
+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);
+
+
+ /* Debug this files internals. */
+ add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger,
+ &frame_debug, "Set frame debugging.\n\
+When non-zero, frame specific internal debugging is enabled.", &setdebuglist),
+ &showdebuglist);
+}
projects / deliverable / binutils-gdb.git / blobdiff