/* Cache and manage frames for GDB, the GNU debugger.
- Copyright (C) 1986-2013 Free Software Foundation, Inc.
+ Copyright (C) 1986-2014 Free Software Foundation, Inc.
This file is part of GDB.
#include "inferior.h" /* for inferior_ptid */
#include "regcache.h"
#include "gdb_assert.h"
-#include "gdb_string.h"
+#include <string.h>
#include "user-regs.h"
#include "gdb_obstack.h"
#include "dummy-frame.h"
#include "inline-frame.h"
#include "tracepoint.h"
#include "hashtab.h"
+#include "valprint.h"
static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
static struct frame_info *get_prev_frame_raw (struct frame_info *this_frame);
+static const char *frame_stop_reason_symbol_string (enum unwind_stop_reason reason);
+
+/* Status of some values cached in the frame_info object. */
+
+enum cached_copy_status
+{
+ /* Value is unknown. */
+ CC_UNKNOWN,
+
+ /* We have a value. */
+ CC_VALUE,
+
+ /* Value was not saved. */
+ CC_NOT_SAVED,
+
+ /* Value is unavailable. */
+ CC_UNAVAILABLE
+};
/* We keep a cache of stack frames, each of which is a "struct
frame_info". The innermost one gets allocated (in
/* Cached copy of the previous frame's resume address. */
struct {
- int p;
+ enum cached_copy_status status;
CORE_ADDR value;
} prev_pc;
const struct frame_id f_id = frame->this_id.value;
hashval_t hash = 0;
- gdb_assert (f_id.stack_addr_p || f_id.code_addr_p
+ gdb_assert (f_id.stack_status != FID_STACK_INVALID
+ || f_id.code_addr_p
|| f_id.special_addr_p);
- if (f_id.stack_addr_p)
+ if (f_id.stack_status == FID_STACK_VALID)
hash = iterative_hash (&f_id.stack_addr,
sizeof (f_id.stack_addr), hash);
if (f_id.code_addr_p)
NULL);
}
-/* Internal function to add a frame to the frame_stash hash table. Do
- not store frames below 0 as they may not have any addresses to
- calculate a hash. */
+/* Internal function to add a frame to the frame_stash hash table.
+ Returns false if a frame with the same ID was already stashed, true
+ otherwise. */
-static void
+static int
frame_stash_add (struct frame_info *frame)
{
- /* Do not stash frames below level 0. */
- if (frame->level >= 0)
- {
- struct frame_info **slot;
+ struct frame_info **slot;
- slot = (struct frame_info **) htab_find_slot (frame_stash,
- frame,
- INSERT);
- *slot = frame;
- }
+ /* Do not try to stash the sentinel frame. */
+ gdb_assert (frame->level >= 0);
+
+ slot = (struct frame_info **) htab_find_slot (frame_stash,
+ frame,
+ INSERT);
+
+ /* If we already have a frame in the stack with the same id, we
+ either have a stack cycle (corrupted stack?), or some bug
+ elsewhere in GDB. In any case, ignore the duplicate and return
+ an indication to the caller. */
+ if (*slot != NULL)
+ return 0;
+
+ *slot = frame;
+ return 1;
}
/* Internal function to search the frame stash for an entry with the
fprint_frame_id (struct ui_file *file, struct frame_id id)
{
fprintf_unfiltered (file, "{");
- fprint_field (file, "stack", id.stack_addr_p, id.stack_addr);
+
+ if (id.stack_status == FID_STACK_INVALID)
+ fprintf_unfiltered (file, "!stack");
+ else if (id.stack_status == FID_STACK_UNAVAILABLE)
+ fprintf_unfiltered (file, "stack=<unavailable>");
+ else
+ fprintf_unfiltered (file, "stack=%s", hex_string (id.stack_addr));
fprintf_unfiltered (file, ",");
+
fprint_field (file, "code", id.code_addr_p, id.code_addr);
fprintf_unfiltered (file, ",");
+
fprint_field (file, "special", id.special_addr_p, id.special_addr);
+
if (id.artificial_depth)
fprintf_unfiltered (file, ",artificial=%d", id.artificial_depth);
+
fprintf_unfiltered (file, "}");
}
fprintf_unfiltered (file, "<unknown>");
fprintf_unfiltered (file, ",");
fprintf_unfiltered (file, "pc=");
- if (fi->next != NULL && fi->next->prev_pc.p)
- fprintf_unfiltered (file, "%s", hex_string (fi->next->prev_pc.value));
- else
+ if (fi->next == NULL || fi->next->prev_pc.status == CC_UNKNOWN)
fprintf_unfiltered (file, "<unknown>");
+ else if (fi->next->prev_pc.status == CC_VALUE)
+ fprintf_unfiltered (file, "%s",
+ hex_string (fi->next->prev_pc.value));
+ else if (fi->next->prev_pc.status == CC_NOT_SAVED)
+ val_print_not_saved (file);
+ else if (fi->next->prev_pc.status == CC_UNAVAILABLE)
+ val_print_unavailable (file);
fprintf_unfiltered (file, ",");
fprintf_unfiltered (file, "id=");
if (fi->this_id.p)
return frame;
}
+/* Compute the frame's uniq ID that can be used to, later, re-find the
+ frame. */
+
+static void
+compute_frame_id (struct frame_info *fi)
+{
+ gdb_assert (!fi->this_id.p);
+
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog, "{ compute_frame_id (fi=%d) ",
+ fi->level);
+ /* Find the unwinder. */
+ if (fi->unwind == NULL)
+ frame_unwind_find_by_frame (fi, &fi->prologue_cache);
+ /* Find THIS frame's ID. */
+ /* Default to outermost if no ID is found. */
+ fi->this_id.value = outer_frame_id;
+ fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value);
+ gdb_assert (frame_id_p (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 a frame uniq ID that can be used to, later, re-find the
frame. */
if (fi == NULL)
return null_frame_id;
- if (!fi->this_id.p)
- {
- if (frame_debug)
- fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ",
- fi->level);
- /* Find the unwinder. */
- if (fi->unwind == NULL)
- frame_unwind_find_by_frame (fi, &fi->prologue_cache);
- /* Find THIS frame's ID. */
- /* Default to outermost if no ID is found. */
- fi->this_id.value = outer_frame_id;
- fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value);
- gdb_assert (frame_id_p (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");
- }
- frame_stash_add (fi);
- }
-
+ gdb_assert (fi->this_id.p);
return fi->this_id.value;
}
}
const struct frame_id null_frame_id; /* All zeros. */
-const struct frame_id outer_frame_id = { 0, 0, 0, 0, 0, 1, 0 };
+const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_INVALID, 0, 1, 0 };
struct frame_id
frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr,
struct frame_id id = null_frame_id;
id.stack_addr = stack_addr;
- id.stack_addr_p = 1;
+ id.stack_status = FID_STACK_VALID;
+ id.code_addr = code_addr;
+ id.code_addr_p = 1;
+ id.special_addr = special_addr;
+ id.special_addr_p = 1;
+ return id;
+}
+
+/* See frame.h. */
+
+struct frame_id
+frame_id_build_unavailable_stack (CORE_ADDR code_addr)
+{
+ struct frame_id id = null_frame_id;
+
+ id.stack_status = FID_STACK_UNAVAILABLE;
+ id.code_addr = code_addr;
+ id.code_addr_p = 1;
+ return id;
+}
+
+/* See frame.h. */
+
+struct frame_id
+frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
+ CORE_ADDR special_addr)
+{
+ struct frame_id id = null_frame_id;
+
+ id.stack_status = FID_STACK_UNAVAILABLE;
id.code_addr = code_addr;
id.code_addr_p = 1;
id.special_addr = special_addr;
struct frame_id id = null_frame_id;
id.stack_addr = stack_addr;
- id.stack_addr_p = 1;
+ id.stack_status = FID_STACK_VALID;
id.code_addr = code_addr;
id.code_addr_p = 1;
return id;
struct frame_id id = null_frame_id;
id.stack_addr = stack_addr;
- id.stack_addr_p = 1;
+ id.stack_status = FID_STACK_VALID;
return id;
}
int p;
/* The frame is valid iff it has a valid stack address. */
- p = l.stack_addr_p;
+ p = l.stack_status != FID_STACK_INVALID;
/* outer_frame_id is also valid. */
if (!p && memcmp (&l, &outer_frame_id, sizeof (l)) == 0)
p = 1;
{
int eq;
- if (!l.stack_addr_p && l.special_addr_p
- && !r.stack_addr_p && r.special_addr_p)
+ if (l.stack_status == FID_STACK_INVALID && l.special_addr_p
+ && r.stack_status == FID_STACK_INVALID && r.special_addr_p)
/* The outermost frame marker is equal to itself. This is the
dodgy thing about outer_frame_id, since between execution steps
we might step into another function - from which we can't
unwind either. More thought required to get rid of
outer_frame_id. */
eq = 1;
- else if (!l.stack_addr_p || !r.stack_addr_p)
+ else if (l.stack_status == FID_STACK_INVALID
+ || l.stack_status == FID_STACK_INVALID)
/* Like a NaN, if either ID is invalid, the result is false.
Note that a frame ID is invalid iff it is the null frame ID. */
eq = 0;
- else if (l.stack_addr != r.stack_addr)
+ else if (l.stack_status != r.stack_status || l.stack_addr != r.stack_addr)
/* If .stack addresses are different, the frames are different. */
eq = 0;
else if (l.code_addr_p && r.code_addr_p && l.code_addr != r.code_addr)
{
int inner;
- if (!l.stack_addr_p || !r.stack_addr_p)
- /* Like NaN, any operation involving an invalid ID always fails. */
+ if (l.stack_status != FID_STACK_VALID || r.stack_status != FID_STACK_VALID)
+ /* Like NaN, any operation involving an invalid ID always fails.
+ Likewise if either ID has an unavailable stack address. */
inner = 0;
else if (l.artificial_depth > r.artificial_depth
&& l.stack_addr == r.stack_addr
return NULL;
}
-static int
-frame_unwind_pc_if_available (struct frame_info *this_frame, CORE_ADDR *pc)
+static CORE_ADDR
+frame_unwind_pc (struct frame_info *this_frame)
{
- if (!this_frame->prev_pc.p)
+ if (this_frame->prev_pc.status == CC_UNKNOWN)
{
if (gdbarch_unwind_pc_p (frame_unwind_arch (this_frame)))
{
{
pc = gdbarch_unwind_pc (prev_gdbarch, this_frame);
}
- if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR)
- {
- this_frame->prev_pc.p = -1;
-
- if (frame_debug)
- fprintf_unfiltered (gdb_stdlog,
- "{ frame_unwind_pc (this_frame=%d)"
- " -> <unavailable> }\n",
- this_frame->level);
- }
- else if (ex.reason < 0)
+ if (ex.reason < 0)
{
- throw_exception (ex);
+ if (ex.error == NOT_AVAILABLE_ERROR)
+ {
+ this_frame->prev_pc.status = CC_UNAVAILABLE;
+
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_unwind_pc (this_frame=%d)"
+ " -> <unavailable> }\n",
+ this_frame->level);
+ }
+ else if (ex.error == OPTIMIZED_OUT_ERROR)
+ {
+ this_frame->prev_pc.status = CC_NOT_SAVED;
+
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_unwind_pc (this_frame=%d)"
+ " -> <not saved> }\n",
+ this_frame->level);
+ }
+ else
+ throw_exception (ex);
}
else
{
this_frame->prev_pc.value = pc;
- this_frame->prev_pc.p = 1;
+ this_frame->prev_pc.status = CC_VALUE;
if (frame_debug)
fprintf_unfiltered (gdb_stdlog,
"{ frame_unwind_pc (this_frame=%d) "
else
internal_error (__FILE__, __LINE__, _("No unwind_pc method"));
}
- if (this_frame->prev_pc.p < 0)
- {
- *pc = -1;
- return 0;
- }
- else
- {
- *pc = this_frame->prev_pc.value;
- return 1;
- }
-}
-static CORE_ADDR
-frame_unwind_pc (struct frame_info *this_frame)
-{
- CORE_ADDR pc;
-
- if (!frame_unwind_pc_if_available (this_frame, &pc))
+ if (this_frame->prev_pc.status == CC_VALUE)
+ return this_frame->prev_pc.value;
+ else if (this_frame->prev_pc.status == CC_UNAVAILABLE)
throw_error (NOT_AVAILABLE_ERROR, _("PC not available"));
+ else if (this_frame->prev_pc.status == CC_NOT_SAVED)
+ throw_error (OPTIMIZED_OUT_ERROR, _("PC not saved"));
else
- return pc;
+ internal_error (__FILE__, __LINE__,
+ "unexpected prev_pc status: %d",
+ (int) this_frame->prev_pc.status);
}
CORE_ADDR
return frame_unwind_pc (skip_artificial_frames (this_frame));
}
-int
-frame_unwind_caller_pc_if_available (struct frame_info *this_frame,
- CORE_ADDR *pc)
-{
- return frame_unwind_pc_if_available (skip_artificial_frames (this_frame), pc);
-}
-
int
get_frame_func_if_available (struct frame_info *this_frame, CORE_ADDR *pc)
{
&lval, &addr, &realnum, buf);
if (optimized)
- error (_("Register %d was optimized out"), regnum);
+ throw_error (OPTIMIZED_OUT_ERROR,
+ _("Register %d was not saved"), regnum);
if (unavailable)
throw_error (NOT_AVAILABLE_ERROR,
_("Register %d is not available"), regnum);
{
fprintf_unfiltered (gdb_stdlog, "->");
if (value_optimized_out (value))
- fprintf_unfiltered (gdb_stdlog, " optimized out");
+ {
+ fprintf_unfiltered (gdb_stdlog, " ");
+ val_print_optimized_out (value, gdb_stdlog);
+ }
else
{
if (VALUE_LVAL (value) == lval_register)
frame_register (frame, regnum, &optim, &unavail,
&lval, &addr, &realnum, NULL);
if (optim)
- error (_("Attempt to assign to a value that was optimized out."));
+ error (_("Attempt to assign to a register that was not saved."));
switch (lval)
{
case lval_memory:
very likely to read this, and the corresponding unwinder is
entitled to rely that the PC doesn't magically change. */
fi->next->prev_pc.value = pc;
- fi->next->prev_pc.p = 1;
+ fi->next->prev_pc.status = CC_VALUE;
/* We currently assume that frame chain's can't cross spaces. */
fi->pspace = fi->next->pspace;
}
}
+/* Get the previous raw frame, and check that it is not identical to
+ same other frame frame already in the chain. If it is, there is
+ most likely a stack cycle, so we discard it, and mark THIS_FRAME as
+ outermost, with UNWIND_SAME_ID stop reason. Unlike the other
+ validity tests, that compare THIS_FRAME and the next frame, we do
+ this right after creating the previous frame, to avoid ever ending
+ up with two frames with the same id in the frame chain. */
+
+static struct frame_info *
+get_prev_frame_if_no_cycle (struct frame_info *this_frame)
+{
+ struct frame_info *prev_frame;
+
+ prev_frame = get_prev_frame_raw (this_frame);
+ if (prev_frame == NULL)
+ return NULL;
+
+ compute_frame_id (prev_frame);
+ if (frame_stash_add (prev_frame))
+ return prev_frame;
+
+ /* Another frame with the same id was already in the stash. We just
+ detected a cycle. */
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "-> ");
+ fprint_frame (gdb_stdlog, NULL);
+ fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n");
+ }
+ this_frame->stop_reason = UNWIND_SAME_ID;
+ /* Unlink. */
+ prev_frame->next = NULL;
+ this_frame->prev = NULL;
+ return NULL;
+}
+
/* Return a "struct frame_info" corresponding to the frame that called
THIS_FRAME. Returns NULL if there is no such frame.
static struct frame_info *
get_prev_frame_1 (struct frame_info *this_frame)
{
- struct frame_id this_id;
struct gdbarch *gdbarch;
gdb_assert (this_frame != NULL);
until we have unwound all the way down to the previous non-inline
frame. */
if (get_frame_type (this_frame) == INLINE_FRAME)
- return get_prev_frame_raw (this_frame);
+ return get_prev_frame_if_no_cycle (this_frame);
/* Check that this frame is unwindable. If it isn't, don't try to
unwind to the prev frame. */
&this_frame->prologue_cache);
if (this_frame->stop_reason != UNWIND_NO_REASON)
- return NULL;
-
- /* 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. */
- this_id = get_frame_id (this_frame);
- if (this_frame->level >= 0 && frame_id_eq (this_id, outer_frame_id))
{
if (frame_debug)
{
+ enum unwind_stop_reason reason = this_frame->stop_reason;
+
fprintf_unfiltered (gdb_stdlog, "-> ");
fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n");
+ fprintf_unfiltered (gdb_stdlog, " // %s }\n",
+ frame_stop_reason_symbol_string (reason));
}
- this_frame->stop_reason = UNWIND_NULL_ID;
return NULL;
}
See the comment at frame_id_inner for details. */
if (get_frame_type (this_frame) == NORMAL_FRAME
&& this_frame->next->unwind->type == NORMAL_FRAME
- && frame_id_inner (get_frame_arch (this_frame->next), this_id,
+ && frame_id_inner (get_frame_arch (this_frame->next),
+ get_frame_id (this_frame),
get_frame_id (this_frame->next)))
{
CORE_ADDR this_pc_in_block;
this_pc_in_block = get_frame_address_in_block (this_frame);
morestack_msym = lookup_minimal_symbol_by_pc (this_pc_in_block).minsym;
if (morestack_msym)
- morestack_name = SYMBOL_LINKAGE_NAME (morestack_msym);
+ morestack_name = MSYMBOL_LINKAGE_NAME (morestack_msym);
if (!morestack_name || strcmp (morestack_name, "__morestack") != 0)
{
if (frame_debug)
}
}
- /* Check that this and the next frame are not identical. If they
- are, there is most likely a stack cycle. As with the inner-than
- test above, avoid comparing the inner-most and sentinel frames. */
- if (this_frame->level > 0
- && frame_id_eq (this_id, get_frame_id (this_frame->next)))
- {
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n");
- }
- this_frame->stop_reason = UNWIND_SAME_ID;
- return NULL;
- }
-
/* Check that this and the next frame do not unwind the PC register
to the same memory location. If they do, then even though they
have different frame IDs, the new frame will be bogus; two
}
}
- return get_prev_frame_raw (this_frame);
+ return get_prev_frame_if_no_cycle (this_frame);
}
/* Construct a new "struct frame_info" and link it previous to
static int
inside_main_func (struct frame_info *this_frame)
{
- struct minimal_symbol *msymbol;
+ struct bound_minimal_symbol msymbol;
CORE_ADDR maddr;
if (symfile_objfile == 0)
return 0;
msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
- if (msymbol == NULL)
+ if (msymbol.minsym == NULL)
return 0;
/* Make certain that the code, and not descriptor, address is
returned. */
maddr = gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame),
- SYMBOL_VALUE_ADDRESS (msymbol),
+ BMSYMBOL_VALUE_ADDRESS (msymbol),
¤t_target);
return maddr == get_frame_func (this_frame);
}
enum unwind_stop_reason
get_frame_unwind_stop_reason (struct frame_info *frame)
{
- /* If we haven't tried to unwind past this point yet, then assume
- that unwinding would succeed. */
- if (frame->prev_p == 0)
- return UNWIND_NO_REASON;
+ /* Fill-in STOP_REASON. */
+ get_prev_frame_1 (frame);
+ gdb_assert (frame->prev_p);
- /* Otherwise, we set a reason when we succeeded (or failed) to
- unwind. */
return frame->stop_reason;
}
}
}
+/* Return the enum symbol name of REASON as a string, to use in debug
+ output. */
+
+static const char *
+frame_stop_reason_symbol_string (enum unwind_stop_reason reason)
+{
+ switch (reason)
+ {
+#define SET(name, description) \
+ case name: return #name;
+#include "unwind_stop_reasons.def"
+#undef SET
+
+ default:
+ internal_error (__FILE__, __LINE__,
+ "Invalid frame stop reason");
+ }
+}
+
/* Clean up after a failed (wrong unwinder) attempt to unwind past
FRAME. */
projects / deliverable / binutils-gdb.git / blobdiff