/* 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 "frame-base.h"
+#include "command.h"
+#include "gdbcmd.h"
+
+/* We keep a cache of stack frames, each of which is a "struct
+ frame_info". The innermost one gets allocated (in
+ wait_for_inferior) each time the inferior stops; current_frame
+ points to it. Additional frames get allocated (in get_prev_frame)
+ as needed, and are chained through the next and prev fields. Any
+ time that the frame cache becomes invalid (most notably when we
+ execute something, but also if we change how we interpret the
+ frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
+ which reads new symbols)), we should call reinit_frame_cache. */
+
+struct frame_info
+{
+ /* Level of this frame. The inner-most (youngest) frame is at level
+ 0. As you move towards the outer-most (oldest) frame, the level
+ increases. This is a cached value. It could just as easily be
+ computed by counting back from the selected frame to the inner
+ most frame. */
+ /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
+ reserved to indicate a bogus frame - one that has been created
+ just to keep GDB happy (GDB always needs a frame). For the
+ moment leave this as speculation. */
+ int level;
+
+ /* The frame's type. */
+ /* FIXME: cagney/2003-04-02: Should instead be returning
+ ->unwind->type. Unfortunatly, legacy code is still explicitly
+ setting the type using the method deprecated_set_frame_type.
+ Eliminate that method and this field can be eliminated. */
+ enum frame_type type;
+
+ /* For each register, address of where it was saved on entry to the
+ frame, or zero if it was not saved on entry to this frame. This
+ includes special registers such as pc and fp saved in special
+ ways in the stack frame. The SP_REGNUM is even more special, the
+ address here is the sp for the previous frame, not the address
+ where the sp was saved. */
+ /* Allocated by frame_saved_regs_zalloc () which is called /
+ initialized by DEPRECATED_FRAME_INIT_SAVED_REGS(). */
+ CORE_ADDR *saved_regs; /*NUM_REGS + NUM_PSEUDO_REGS*/
+
+ /* Anything extra for this structure that may have been defined in
+ the machine dependent files. */
+ /* Allocated by frame_extra_info_zalloc () which is called /
+ initialized by DEPRECATED_INIT_EXTRA_FRAME_INFO */
+ struct frame_extra_info *extra_info;
+
+ /* If dwarf2 unwind frame informations is used, this structure holds
+ all related unwind data. */
+ struct context *context;
+
+ /* The frame's low-level unwinder and corresponding cache. The
+ low-level unwinder is responsible for unwinding register values
+ for the previous frame. The low-level unwind methods are
+ selected based on the presence, or otherwize, of register unwind
+ information such as CFI. */
+ void *prologue_cache;
+ const struct frame_unwind *unwind;
+
+ /* Cached copy of the previous frame's resume address. */
+ struct {
+ int p;
+ CORE_ADDR value;
+ } prev_pc;
+
+ /* Cached copy of the previous frame's function address. */
+ struct
+ {
+ CORE_ADDR addr;
+ int p;
+ } prev_func;
+
+ /* This frame's ID. */
+ struct
+ {
+ int p;
+ struct frame_id value;
+ } this_id;
+
+ /* The frame's high-level base methods, and corresponding cache.
+ The high level base methods are selected based on the frame's
+ debug info. */
+ const struct frame_base *base;
+ void *base_cache;
+
+ /* Pointers to the next (down, inner, younger) and previous (up,
+ outer, older) frame_info's in the frame cache. */
+ struct frame_info *next; /* down, inner, younger */
+ int prev_p;
+ struct frame_info *prev; /* up, outer, older */
+};
+
+/* Flag to control debugging. */
+
+static int frame_debug;
+
+/* Flag to indicate whether backtraces should stop at main. */
+
+static int backtrace_below_main;
+
+void
+fprint_frame_id (struct ui_file *file, struct frame_id id)
+{
+ fprintf_unfiltered (file, "{stack=0x%s,code=0x%s}",
+ paddr_nz (id.stack_addr),
+ paddr_nz (id.code_addr));
+}
+
+static void
+fprint_frame_type (struct ui_file *file, enum frame_type type)
+{
+ switch (type)
+ {
+ case UNKNOWN_FRAME:
+ fprintf_unfiltered (file, "UNKNOWN_FRAME");
+ return;
+ case NORMAL_FRAME:
+ fprintf_unfiltered (file, "NORMAL_FRAME");
+ return;
+ case DUMMY_FRAME:
+ fprintf_unfiltered (file, "DUMMY_FRAME");
+ return;
+ case SIGTRAMP_FRAME:
+ fprintf_unfiltered (file, "SIGTRAMP_FRAME");
+ return;
+ default:
+ fprintf_unfiltered (file, "<unknown type>");
+ return;
+ };
+}
+
+static void
+fprint_frame (struct ui_file *file, struct frame_info *fi)
+{
+ if (fi == NULL)
+ {
+ fprintf_unfiltered (file, "<NULL frame>");
+ return;
+ }
+ fprintf_unfiltered (file, "{");
+ fprintf_unfiltered (file, "level=%d", fi->level);
+ fprintf_unfiltered (file, ",");
+ fprintf_unfiltered (file, "type=");
+ fprint_frame_type (file, fi->type);
+ fprintf_unfiltered (file, ",");
+ fprintf_unfiltered (file, "unwind=");
+ if (fi->unwind != NULL)
+ gdb_print_host_address (fi->unwind, file);
+ else
+ fprintf_unfiltered (file, "<unknown>");
+ fprintf_unfiltered (file, ",");
+ fprintf_unfiltered (file, "pc=");
+ if (fi->next != NULL && fi->next->prev_pc.p)
+ fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_pc.value));
+ else
+ fprintf_unfiltered (file, "<unknown>");
+ fprintf_unfiltered (file, ",");
+ fprintf_unfiltered (file, "id=");
+ if (fi->this_id.p)
+ fprint_frame_id (file, fi->this_id.value);
+ else
+ fprintf_unfiltered (file, "<unknown>");
+ fprintf_unfiltered (file, ",");
+ fprintf_unfiltered (file, "func=");
+ if (fi->next != NULL && fi->next->prev_func.p)
+ fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_func.addr));
+ else
+ fprintf_unfiltered (file, "<unknown>");
+ fprintf_unfiltered (file, "}");
+}
-/* Return a frame uniq ID that can be used to, later re-find the
+/* 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;
}
+ if (!fi->this_id.p)
+ {
+ gdb_assert (!legacy_frame_p (current_gdbarch));
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ",
+ fi->level);
+ /* Find the unwinder. */
+ if (fi->unwind == NULL)
+ {
+ fi->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (fi));
+ /* 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 (fi->unwind->type != UNKNOWN_FRAME);
+ fi->type = fi->unwind->type;
+ }
+ /* Find THIS frame's ID. */
+ fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
+ fi->this_id.p = 1;
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame_id (gdb_stdlog, fi->this_id.value);
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
+ }
+ return fi->this_id.value;
+}
+
+const struct frame_id null_frame_id; /* All zeros. */
+
+struct frame_id
+frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr)
+{
+ struct frame_id id;
+ id.stack_addr = stack_addr;
+ id.code_addr = code_addr;
+ return id;
+}
+
+int
+frame_id_p (struct frame_id l)
+{
+ int p;
+ /* The .code can be NULL but the .stack cannot. */
+ p = (l.stack_addr != 0);
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l=");
+ fprint_frame_id (gdb_stdlog, l);
+ fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p);
+ }
+ return p;
+}
+
+int
+frame_id_eq (struct frame_id l, struct frame_id r)
+{
+ int eq;
+ if (l.stack_addr == 0 || r.stack_addr == 0)
+ /* Like a NaN, if either ID is invalid, the result is false. */
+ eq = 0;
+ else if (l.stack_addr != r.stack_addr)
+ /* If .stack addresses are different, the frames are different. */
+ eq = 0;
+ else if (l.code_addr == 0 || r.code_addr == 0)
+ /* A zero code addr is a wild card, always succeed. */
+ eq = 1;
+ else if (l.code_addr == r.code_addr)
+ /* The .stack and .code are identical, the ID's are identical. */
+ eq = 1;
+ else
+ /* No luck. */
+ eq = 0;
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l=");
+ fprint_frame_id (gdb_stdlog, l);
+ fprintf_unfiltered (gdb_stdlog, ",r=");
+ fprint_frame_id (gdb_stdlog, r);
+ fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq);
+ }
+ return eq;
+}
+
+int
+frame_id_inner (struct frame_id l, struct frame_id r)
+{
+ int inner;
+ if (l.stack_addr == 0 || r.stack_addr == 0)
+ /* Like NaN, any operation involving an invalid ID always fails. */
+ inner = 0;
else
+ /* 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 .stack but
+ different .code). */
+ inner = INNER_THAN (l.stack_addr, r.stack_addr);
+ if (frame_debug)
{
- id->base = FRAME_FP (fi);
- id->pc = fi->pc;
+ fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l=");
+ fprint_frame_id (gdb_stdlog, l);
+ fprintf_unfiltered (gdb_stdlog, ",r=");
+ fprint_frame_id (gdb_stdlog, r);
+ fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner);
}
+ return inner;
}
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->prev_pc.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_unsigned_integer (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->prev_pc.value = pc;
+ this_frame->prev_pc.p = 1;
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n",
+ this_frame->level,
+ paddr_nz (this_frame->prev_pc.value));
+ }
+ return this_frame->prev_pc.value;
+}
+
+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));
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
+ fi->level, paddr_nz (fi->prev_func.addr));
+ }
+ 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,
{
struct frame_unwind_cache *cache;
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_register_unwind (frame=%d,regnum=\"%s\",...) ",
+ frame->level, frame_map_regnum_to_name (regnum));
+ }
+
/* 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 (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);
- if (frame == NULL)
+ /* Find the unwinder. */
+ if (frame->unwind == 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;
+ frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (frame));
+ /* 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 (frame->unwind->type != UNKNOWN_FRAME);
+ frame->type = frame->unwind->type;
}
- /* Ask this frame to unwind its register. */
- frame->register_unwind (frame, &frame->register_unwind_cache, regnum,
- optimizedp, lvalp, addrp, realnump, bufferp);
+ /* 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_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "->");
+ fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp));
+ fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp));
+ fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp)));
+ fprintf_unfiltered (gdb_stdlog, " *bufferp=");
+ if (bufferp == NULL)
+ fprintf_unfiltered (gdb_stdlog, "<NULL>");
+ else
+ {
+ int i;
+ const char *buf = bufferp;
+ fprintf_unfiltered (gdb_stdlog, "[");
+ for (i = 0; i < register_size (current_gdbarch, regnum); i++)
+ fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
+ fprintf_unfiltered (gdb_stdlog, "]");
+ }
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
}
void
/* 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 (GET_SAVED_REGISTER_P ())
+ if (DEPRECATED_GET_SAVED_REGISTER_P ())
{
- GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, regnum, lvalp);
+ DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame,
+ regnum, lvalp);
/* Compute the REALNUM if the caller wants it. */
if (*lvalp == lval_register)
{
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
-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)
+{
+ char buf[MAX_REGISTER_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);
+ char buf[MAX_REGISTER_SIZE];
+ 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)
-{
- if (GET_SAVED_REGISTER_P ())
- {
- GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval);
- return;
- }
- generic_unwind_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 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 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;
+ /* Make the sentinel frame's ID valid, but invalid. That way all
+ comparisons with it should fail. */
+ frame->this_id.p = 1;
+ frame->this_id.value = null_frame_id;
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> ");
+ fprint_frame (gdb_stdlog, frame);
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
+ 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)
{
+ /* 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)
{
- 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 (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.
most frame. */
static void
-frame_saved_regs_register_unwind (struct frame_info *frame, void **cache,
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnump, void *bufferp)
+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)
{
- /* There is always a frame at this point. And THIS is the frame
- we're interested in. */
+ /* 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);
- /* If we're using generic dummy frames, we'd better not be in a call
- dummy. (generic_call_dummy_register_unwind ought to have been called
- instead.) */
- gdb_assert (!(USE_GENERIC_DUMMY_FRAMES
- && PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)));
+
+ /* 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 (frame->saved_regs == NULL)
- FRAME_INIT_SAVED_REGS (frame);
+ if (get_frame_saved_regs (frame) == NULL)
+ DEPRECATED_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)
{
*addrp = 0;
*realnump = -1;
if (bufferp != NULL)
- store_address (bufferp, REGISTER_RAW_SIZE (regnum),
- frame->saved_regs[regnum]);
+ /* NOTE: cagney/2003-05-09: In-lined store_address with
+ it's body - store_unsigned_integer. */
+ store_unsigned_integer (bufferp, REGISTER_RAW_SIZE (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)
{
#if 1
/* Save each register value, as it is read in, in a
frame based cache. */
- void **regs = (*cache);
+ void **regs = (*this_prologue_cache);
if (regs == NULL)
{
int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
* sizeof (void *));
- regs = frame_obstack_alloc (sizeof_cache);
- memset (regs, 0, sizeof_cache);
- (*cache) = regs;
+ regs = frame_obstack_zalloc (sizeof_cache);
+ (*this_prologue_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
}
return;
}
- /* 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);
- }
+ /* 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)
+{
+ /* legacy_get_prev_frame() always sets ->this_id.p, hence this is
+ never needed. */
+ internal_error (__FILE__, __LINE__, "legacy_saved_regs_this_id() called");
}
+
+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: get_saved_register
+
+/* Function: deprecated_generic_get_saved_register
Find register number REGNUM relative to FRAME and put its (raw,
- target format) contents in *RAW_BUFFER.
+ 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
offset into the registers array. If the value is stored in a dummy
frame, set *ADDRP to zero.
- To use this implementation, define a function called
- "get_saved_register" in your target code, which simply passes all
- of its arguments to this function.
-
The argument RAW_BUFFER must point to aligned memory. */
void
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;
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 (PC_IN_CALL_DUMMY (frame->pc, frame->frame, 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)
+ for (frame = get_next_frame (frame);
+ frame_relative_level (frame) >= 0;
+ frame = get_next_frame (frame))
{
- if (lval) /* found it saved on the stack */
- *lval = lval_memory;
- if (regnum == SP_REGNUM)
+ if (get_frame_type (frame) == DUMMY_FRAME)
{
- if (raw_buffer) /* SP register treated specially */
- store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
- frame->saved_regs[regnum]);
+ if (lval) /* found it in a CALL_DUMMY frame */
+ *lval = not_lval;
+ if (raw_buffer)
+ /* FIXME: cagney/2002-06-26: This should be via the
+ gdbarch_register_read() method so that it, on the
+ fly, constructs either a raw or pseudo register
+ from the raw register cache. */
+ regcache_raw_read
+ (deprecated_find_dummy_frame_regcache (get_frame_pc (frame),
+ get_frame_base (frame)),
+ regnum, raw_buffer);
+ return;
}
- else
+
+ DEPRECATED_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 */
+ /* NOTE: cagney/2003-05-09: In-line store_address
+ with it's body - store_unsigned_integer. */
+ store_unsigned_integer (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)
-{
- if (!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 = frame_saved_regs_register_unwind;
- else if (PC_IN_CALL_DUMMY (pc, fp, fp))
- *unwind = dummy_frame_register_unwind;
+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
- *unwind = frame_saved_regs_register_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 an arbitrary (i.e. address specified by user) or innermost frame.
create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
{
struct frame_info *fi;
- char *name;
- fi = (struct frame_info *)
- obstack_alloc (&frame_cache_obstack,
- sizeof (struct frame_info));
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "{ create_new_frame (addr=0x%s, pc=0x%s) ",
+ paddr_nz (addr), paddr_nz (pc));
+ }
+
+ fi = frame_obstack_zalloc (sizeof (struct frame_info));
- /* Zero all fields by default. */
- memset (fi, 0, sizeof (struct frame_info));
+ fi->next = create_sentinel_frame (current_regcache);
- fi->frame = addr;
- fi->pc = pc;
- find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
- fi->signal_handler_caller = PC_IN_SIGTRAMP (fi->pc, name);
+ /* Select/initialize both the unwind function and the frame's type
+ based on the PC. */
+ fi->unwind = frame_unwind_find_by_pc (current_gdbarch, pc);
+ if (fi->unwind->type != UNKNOWN_FRAME)
+ fi->type = fi->unwind->type;
+ else
+ fi->type = frame_type_from_pc (pc);
- if (INIT_EXTRA_FRAME_INFO_P ())
- INIT_EXTRA_FRAME_INFO (0, fi);
+ fi->this_id.p = 1;
+ deprecated_update_frame_base_hack (fi, addr);
+ deprecated_update_frame_pc_hack (fi, pc);
- /* Select/initialize an unwind function. */
- set_unwind_by_pc (fi->pc, fi->frame, &fi->register_unwind);
+ if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
+ DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, fi);
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
return fi;
}
-/* Return the frame that FRAME calls (NULL if FRAME is the innermost
- frame). */
+/* 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 *frame)
+get_next_frame (struct frame_info *this_frame)
{
- return frame->next;
+ if (this_frame->level > 0)
+ return this_frame->next;
+ else
+ return NULL;
}
/* Flush the entire frame cache. */
current_frame = NULL; /* Invalidate cache */
select_frame (NULL);
annotate_frames_invalid ();
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n");
}
/* Flush the frame cache, and start a new one if necessary. */
}
}
-/* 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 *this_frame)
{
CORE_ADDR address = 0;
struct frame_info *prev;
int fromleaf;
- char *name;
- /* 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)
+ /* Don't frame_debug print legacy_get_prev_frame() here, just
+ confuses the output. */
+
+ /* 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->this_id.p = 1;
+
+ /* Handle sentinel frame unwind as a special case. */
+ if (this_frame->level < 0)
{
- /* 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 ...
+ /* 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, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog,
+ " // unwound legacy PC zero }\n");
+ }
+ return NULL;
+ }
- ``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.''
+ /* Set the unwind functions based on that identified PC. Ditto
+ for the "type" but strongly prefer the unwinder's frame type. */
+ prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (prev));
+ if (prev->unwind->type == UNKNOWN_FRAME)
+ prev->type = frame_type_from_pc (get_frame_pc (prev));
+ else
+ prev->type = prev->unwind->type;
- Per the above, this code shouldn't even be called with a NULL
- NEXT_FRAME. */
- return current_frame;
+ /* 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->this_id.value = 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->this_id.value = frame_id_build (deprecated_read_fp (),
+ read_pc ());
+ }
+
+ /* Check that the unwound ID is valid. */
+ if (!frame_id_p (prev->this_id.value))
+ {
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog,
+ " // unwound legacy 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. */
+
+ /* 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);
+ }
+
+ if (prev->type == NORMAL_FRAME)
+ prev->this_id.value.code_addr
+ = get_pc_function_start (prev->this_id.value.code_addr);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, prev);
+ fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n");
+ }
+ return prev;
}
- /* If we have the prev one, return it. */
- if (next_frame->prev)
- /* FIXME: cagney/2002-11-09: Rather than relying on ->PREV being
- non-NULL, there should be a predicate (->prev_p?). That would
- stop this function constantly trying to chain beyond the
- outermost frame. */
- return next_frame->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
or isn't leafless. */
/* Still don't want to worry about this except on the innermost
- frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
+ frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
function invocation. */
- if (next_frame->next == NULL)
+ 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 (next_frame);
+ fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame);
else
fromleaf = 0;
/* 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 = FRAME_FP (next_frame);
+ address = get_frame_base (this_frame);
else
{
/* Two macros defined in tm.h specify the machine-dependent
this to after the ffi test; I'd rather have backtraces from
start go curfluy than have an abort called from main not show
main. */
- 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))
- return 0;
+ gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
+ address = DEPRECATED_FRAME_CHAIN (this_frame);
+
+ if (!legacy_frame_chain_valid (address, this_frame))
+ {
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog,
+ " // legacy frame chain invalid }\n");
+ }
+ return NULL;
+ }
}
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));
+ {
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog,
+ " // legacy frame chain NULL }\n");
+ }
+ return NULL;
+ }
- /* Link it in. */
- next_frame->prev = prev;
- prev->next = next_frame;
- prev->frame = address;
- prev->level = next_frame->level + 1;
+ /* 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* 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 DEPRECATED_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
- INIT_EXTRA_FRAME_INFO.
+ 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 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.
+ 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 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
- INIT_EXTRA_FRAME_INFO, one possible scheme:
+ 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.
+ (deprecated_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 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
- 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)
+ 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 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. */
inner most and any other case.
Since there is always a frame to unwind from, there is always
- somewhere (NEXT_FRAME) to store all the info needed to construct
+ 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 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. */
+ 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. */
- INIT_FRAME_PC_FIRST (fromleaf, prev);
+ if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
+ deprecated_update_frame_pc_hack (prev,
+ DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf,
+ prev));
- if (INIT_EXTRA_FRAME_INFO_P ())
- INIT_EXTRA_FRAME_INFO (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. */
- INIT_FRAME_PC (fromleaf, prev);
+ 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 FRAME_CHAIN or thereabouts, but it seems like there
- is no reason this can't be an architecture-independent check. */
- if (prev->frame == next_frame->frame
- && prev->pc == next_frame->pc)
+ 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))
{
- next_frame->prev = NULL;
+ this_frame->prev = NULL;
obstack_free (&frame_cache_obstack, prev);
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog,
+ " // legacy this.id == prev.id }\n");
+ }
return NULL;
}
(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->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (prev));
- find_pc_partial_function (prev->pc, &name,
- (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
- if (PC_IN_SIGTRAMP (prev->pc, name))
- prev->signal_handler_caller = 1;
+ /* 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;
+ if (prev->type == NORMAL_FRAME)
+ prev->this_id.value.code_addr
+ = get_pc_function_start (prev->this_id.value.code_addr);
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, prev);
+ fprintf_unfiltered (gdb_stdlog, " } // legacy with unwound type\n");
+ }
+ 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. */
+ }
+
+ if (prev->type == NORMAL_FRAME)
+ prev->this_id.value.code_addr
+ = get_pc_function_start (prev->this_id.value.code_addr);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, prev);
+ fprintf_unfiltered (gdb_stdlog, " } // legacy with confused type\n");
+ }
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;
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
+ if (this_frame != NULL)
+ fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
+ else
+ fprintf_unfiltered (gdb_stdlog, "<NULL>");
+ fprintf_unfiltered (gdb_stdlog, ") ");
+ }
+
+ /* 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, "-> NULL // inside main func }\n");
+ return NULL;
+ }
+
+ /* Only try to do the unwind once. */
+ if (this_frame->prev_p)
+ {
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, this_frame->prev);
+ fprintf_unfiltered (gdb_stdlog, " // cached \n");
+ }
+ 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, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog, " // 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, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog, "// 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);
+ 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_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog, " // 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. */
+
+ if (frame_pc_unwind (this_frame) == 0)
+ {
+ /* The allocated PREV_FRAME will be reclaimed when the frame
+ obstack is next purged. */
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog, " // unwound PC zero }\n");
+ }
+ return NULL;
+ }
+
+ /* Don't yet compute ->unwind (and hence ->type). It is computed
+ on-demand in get_frame_type, frame_register_unwind, and
+ get_frame_id. */
+
+ /* Don't yet compute the frame's ID. It is computed on-demand by
+ 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;
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, prev_frame);
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
+
+ return prev_frame;
+}
+
CORE_ADDR
get_frame_pc (struct frame_info *frame)
{
- return frame->pc;
+ gdb_assert (frame->next != NULL);
+ return frame_pc_unwind (frame->next);
}
-#ifdef FRAME_FIND_SAVED_REGS
-/* XXX - deprecated. This is a compatibility function for targets
- that do not yet implement FRAME_INIT_SAVED_REGS. */
-/* Find the addresses in which registers are saved in FRAME. */
+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
-get_frame_saved_regs (struct frame_info *frame,
- struct frame_saved_regs *saved_regs_addr)
+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)
+{
+ return get_frame_id (fi).stack_addr;
+}
+
+/* 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)
{
- if (frame->saved_regs == NULL)
+ /* 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;
+
+ /* Some legacy code, e.g, mips_init_extra_frame_info() wants
+ to determine the frame's type prior to it being completely
+ initialized. Don't attempt to lazily initialize ->unwind for
+ legacy code. It will be initialized in legacy_get_prev_frame(). */
+ if (frame->unwind == NULL && !legacy_frame_p (current_gdbarch))
{
- frame->saved_regs = (CORE_ADDR *)
- frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
+ /* Initialize the frame's unwinder because it is that which
+ provides the frame's type. */
+ frame->unwind = frame_unwind_find_by_pc (current_gdbarch,
+ get_frame_pc (frame));
+ /* 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 (frame->unwind->type != UNKNOWN_FRAME);
+ frame->type = frame->unwind->type;
}
- if (saved_regs_addr == NULL)
+ 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)
+{
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
+ frame->level, paddr_nz (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)
{
- struct frame_saved_regs saved_regs;
- FRAME_FIND_SAVED_REGS (frame, saved_regs);
- memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS);
+ /* 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->prev_pc.value = pc;
+ frame->next->prev_pc.p = 1;
}
- else
+}
+
+void
+deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
+{
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
+ frame->level, paddr_nz (base));
+ /* See comment in "frame.h". */
+ frame->this_id.value.stack_addr = 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 = FRAME_OBSTACK_ZALLOC (struct frame_info);
+ frame->this_id.p = 1;
+ 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_FIND_SAVED_REGS (frame, *saved_regs_addr);
- memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS);
+ 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 ());
}
-#endif
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