/* Cache and manage frames for GDB, the GNU debugger.
- Copyright (C) 1986-2015 Free Software Foundation, Inc.
+ Copyright (C) 1986-2019 Free Software Foundation, Inc.
This file is part of GDB.
#include "frame-base.h"
#include "command.h"
#include "gdbcmd.h"
-#include "observer.h"
+#include "observable.h"
#include "objfiles.h"
#include "gdbthread.h"
#include "block.h"
#include "hashtab.h"
#include "valprint.h"
+/* The sentinel frame terminates the innermost end of the frame chain.
+ If unwound, it returns the information needed to construct an
+ innermost frame.
+
+ The current frame, which is the innermost frame, can be found at
+ sentinel_frame->prev. */
+
+static struct frame_info *sentinel_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);
/* 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
+ wait_for_inferior) each time the inferior stops; sentinel_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
struct program_space *pspace;
/* The frame's address space. */
- struct address_space *aspace;
+ const address_space *aspace;
/* The frame's low-level unwinder and corresponding cache. The
low-level unwinder is responsible for unwinding register values
static hashval_t
frame_addr_hash (const void *ap)
{
- const struct frame_info *frame = ap;
+ const struct frame_info *frame = (const struct frame_info *) ap;
const struct frame_id f_id = frame->this_id.value;
hashval_t hash = 0;
static int
frame_addr_hash_eq (const void *a, const void *b)
{
- const struct frame_info *f_entry = a;
- const struct frame_info *f_element = b;
+ const struct frame_info *f_entry = (const struct frame_info *) a;
+ const struct frame_info *f_element = (const struct frame_info *) b;
return frame_id_eq (f_entry->this_id.value,
f_element->this_id.value);
struct frame_info *frame;
dummy.this_id.value = id;
- frame = htab_find (frame_stash, &dummy);
+ frame = (struct frame_info *) htab_find (frame_stash, &dummy);
return frame;
}
htab_empty (frame_stash);
}
+/* See frame.h */
+scoped_restore_selected_frame::scoped_restore_selected_frame ()
+{
+ m_fid = get_frame_id (get_selected_frame (NULL));
+}
+
+/* See frame.h */
+scoped_restore_selected_frame::~scoped_restore_selected_frame ()
+{
+ frame_info *frame = frame_find_by_id (m_fid);
+ if (frame == NULL)
+ warning (_("Unable to restore previously selected frame."));
+ else
+ select_frame (frame);
+}
+
/* Flag to control debugging. */
unsigned int frame_debug;
fprintf_unfiltered (file, "!stack");
else if (id.stack_status == FID_STACK_UNAVAILABLE)
fprintf_unfiltered (file, "stack=<unavailable>");
+ else if (id.stack_status == FID_STACK_SENTINEL)
+ fprintf_unfiltered (file, "stack=<sentinel>");
else
fprintf_unfiltered (file, "stack=%s", hex_string (id.stack_addr));
fprintf_unfiltered (file, ",");
/* Given FRAME, return the enclosing frame as found in real frames read-in from
inferior memory. Skip any previous frames which were made up by GDB.
- Return the original frame if no immediate previous frames exist. */
+ Return FRAME if FRAME is a non-artificial frame.
+ Return NULL if FRAME is the start of an artificial-only chain. */
static struct frame_info *
skip_artificial_frames (struct frame_info *frame)
/* Note we use get_prev_frame_always, and not get_prev_frame. The
latter will truncate the frame chain, leading to this function
unintentionally returning a null_frame_id (e.g., when the user
- sets a backtrace limit). This is safe, because as these frames
- are made up by GDB, there must be a real frame in the chain
- below. */
+ sets a backtrace limit).
+
+ Note that for record targets we may get a frame chain that consists
+ of artificial frames only. */
while (get_frame_type (frame) == INLINE_FRAME
|| get_frame_type (frame) == TAILCALL_FRAME)
- frame = get_prev_frame_always (frame);
+ {
+ frame = get_prev_frame_always (frame);
+ if (frame == NULL)
+ break;
+ }
+
+ return frame;
+}
+
+struct frame_info *
+skip_unwritable_frames (struct frame_info *frame)
+{
+ while (gdbarch_code_of_frame_writable (get_frame_arch (frame), frame) == 0)
+ {
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ }
+
+ return frame;
+}
+
+/* See frame.h. */
+
+struct frame_info *
+skip_tailcall_frames (struct frame_info *frame)
+{
+ while (get_frame_type (frame) == TAILCALL_FRAME)
+ {
+ /* Note that for record targets we may get a frame chain that consists of
+ tailcall frames only. */
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ }
return frame;
}
if (fi == NULL)
return null_frame_id;
- gdb_assert (fi->this_id.p);
+ if (!fi->this_id.p)
+ {
+ int stashed;
+
+ /* If we haven't computed the frame id yet, then it must be that
+ this is the current frame. Compute it now, and stash the
+ result. The IDs of other frames are computed as soon as
+ they're created, in order to detect cycles. See
+ get_prev_frame_if_no_cycle. */
+ gdb_assert (fi->level == 0);
+
+ /* Compute. */
+ compute_frame_id (fi);
+
+ /* Since this is the first frame in the chain, this should
+ always succeed. */
+ stashed = frame_stash_add (fi);
+ gdb_assert (stashed);
+ }
+
return fi->this_id.value;
}
requests the frame ID of "main()"s caller. */
next_frame = skip_artificial_frames (next_frame);
+ if (next_frame == NULL)
+ return null_frame_id;
+
this_frame = get_prev_frame_always (next_frame);
if (this_frame)
return get_frame_id (skip_artificial_frames (this_frame));
return null_frame_id;
}
-const struct frame_id null_frame_id; /* All zeros. */
+const struct frame_id null_frame_id = { 0 }; /* All zeros. */
+const struct frame_id sentinel_frame_id = { 0, 0, 0, FID_STACK_SENTINEL, 0, 1, 0 };
const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_INVALID, 0, 1, 0 };
struct frame_id
if (!frame_id_p (id))
return NULL;
+ /* Check for the sentinel frame. */
+ if (frame_id_eq (id, sentinel_frame_id))
+ return sentinel_frame;
+
/* Try using the frame stash first. Finding it there removes the need
to perform the search by looping over all frames, which can be very
CPU-intensive if the number of frames is very high (the loop is O(n)
{
if (this_frame->prev_pc.status == CC_UNKNOWN)
{
- if (gdbarch_unwind_pc_p (frame_unwind_arch (this_frame)))
+ struct gdbarch *prev_gdbarch;
+ CORE_ADDR pc = 0;
+ int pc_p = 0;
+
+ /* 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. */
+ prev_gdbarch = frame_unwind_arch (this_frame);
+
+ TRY
{
- volatile struct gdb_exception ex;
- struct gdbarch *prev_gdbarch;
- CORE_ADDR pc = 0;
-
- /* 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. */
- prev_gdbarch = frame_unwind_arch (this_frame);
-
- TRY_CATCH (ex, RETURN_MASK_ERROR)
- {
- pc = gdbarch_unwind_pc (prev_gdbarch, this_frame);
- }
- if (ex.reason < 0)
+ pc = gdbarch_unwind_pc (prev_gdbarch, this_frame);
+ pc_p = 1;
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (ex.error == NOT_AVAILABLE_ERROR)
{
- 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);
+ 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
+ else if (ex.error == OPTIMIZED_OUT_ERROR)
{
- this_frame->prev_pc.value = pc;
- this_frame->prev_pc.status = CC_VALUE;
+ this_frame->prev_pc.status = CC_NOT_SAVED;
+
if (frame_debug)
fprintf_unfiltered (gdb_stdlog,
- "{ frame_unwind_pc (this_frame=%d) "
- "-> %s }\n",
- this_frame->level,
- hex_string (this_frame->prev_pc.value));
+ "{ frame_unwind_pc (this_frame=%d)"
+ " -> <not saved> }\n",
+ this_frame->level);
}
+ else
+ throw_exception (ex);
+ }
+ END_CATCH
+
+ if (pc_p)
+ {
+ this_frame->prev_pc.value = pc;
+ this_frame->prev_pc.status = CC_VALUE;
+ if (frame_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "{ frame_unwind_pc (this_frame=%d) "
+ "-> %s }\n",
+ this_frame->level,
+ hex_string (this_frame->prev_pc.value));
}
- else
- internal_error (__FILE__, __LINE__, _("No unwind_pc method"));
}
if (this_frame->prev_pc.status == CC_VALUE)
CORE_ADDR
frame_unwind_caller_pc (struct frame_info *this_frame)
{
- return frame_unwind_pc (skip_artificial_frames (this_frame));
+ this_frame = skip_artificial_frames (this_frame);
+
+ /* We must have a non-artificial frame. The caller is supposed to check
+ the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID
+ in this case. */
+ gdb_assert (this_frame != NULL);
+
+ return frame_unwind_pc (this_frame);
}
int
return pc;
}
-static enum register_status
-do_frame_register_read (void *src, int regnum, gdb_byte *buf)
-{
- if (!deprecated_frame_register_read (src, regnum, buf))
- return REG_UNAVAILABLE;
- else
- return REG_VALID;
-}
-
-struct regcache *
+std::unique_ptr<readonly_detached_regcache>
frame_save_as_regcache (struct frame_info *this_frame)
{
- struct address_space *aspace = get_frame_address_space (this_frame);
- struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame),
- aspace);
- struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
+ auto cooked_read = [this_frame] (int regnum, gdb_byte *buf)
+ {
+ if (!deprecated_frame_register_read (this_frame, regnum, buf))
+ return REG_UNAVAILABLE;
+ else
+ return REG_VALID;
+ };
+
+ std::unique_ptr<readonly_detached_regcache> regcache
+ (new readonly_detached_regcache (get_frame_arch (this_frame), cooked_read));
- regcache_save (regcache, do_frame_register_read, this_frame);
- discard_cleanups (cleanups);
return regcache;
}
frame_pop (struct frame_info *this_frame)
{
struct frame_info *prev_frame;
- struct regcache *scratch;
- struct cleanup *cleanups;
if (get_frame_type (this_frame) == DUMMY_FRAME)
{
/* Popping a dummy frame involves restoring more than just registers.
dummy_frame_pop does all the work. */
- dummy_frame_pop (get_frame_id (this_frame), inferior_ptid);
+ dummy_frame_pop (get_frame_id (this_frame), inferior_thread ());
return;
}
/* Ignore TAILCALL_FRAME type frames, they were executed already before
entering THISFRAME. */
- while (get_frame_type (prev_frame) == TAILCALL_FRAME)
- prev_frame = get_prev_frame (prev_frame);
+ prev_frame = skip_tailcall_frames (prev_frame);
+
+ if (prev_frame == NULL)
+ error (_("Cannot find the caller frame."));
/* 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 between
trying to extract the old values from the current regcache while
at the same time writing new values into that same cache. */
- scratch = frame_save_as_regcache (prev_frame);
- cleanups = make_cleanup_regcache_xfree (scratch);
+ std::unique_ptr<readonly_detached_regcache> scratch
+ = frame_save_as_regcache (prev_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
Unfortunately, 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 (get_current_regcache (), scratch);
- do_cleanups (cleanups);
+ /* Now copy those saved registers into the current regcache. */
+ get_current_regcache ()->restore (scratch.get ());
/* We've made right mess of GDB's local state, just discard
everything. */
}
void
-frame_register_unwind (struct frame_info *frame, int regnum,
+frame_register_unwind (frame_info *next_frame, int regnum,
int *optimizedp, int *unavailablep,
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnump, gdb_byte *bufferp)
gdb_assert (realnump != NULL);
/* gdb_assert (bufferp != NULL); */
- value = frame_unwind_register_value (frame, regnum);
+ value = frame_unwind_register_value (next_frame, regnum);
gdb_assert (value != NULL);
*unavailablep = !value_entirely_available (value);
*lvalp = VALUE_LVAL (value);
*addrp = value_address (value);
- *realnump = VALUE_REGNUM (value);
+ if (*lvalp == lval_register)
+ *realnump = VALUE_REGNUM (value);
+ else
+ *realnump = -1;
if (bufferp)
{
/* Dispose of the new value. This prevents watchpoints from
trying to watch the saved frame pointer. */
release_value (value);
- value_free (value);
}
void
}
void
-frame_unwind_register (struct frame_info *frame, int regnum, gdb_byte *buf)
+frame_unwind_register (frame_info *next_frame, int regnum, gdb_byte *buf)
{
int optimized;
int unavailable;
int realnum;
enum lval_type lval;
- frame_register_unwind (frame, regnum, &optimized, &unavailable,
+ frame_register_unwind (next_frame, regnum, &optimized, &unavailable,
&lval, &addr, &realnum, buf);
if (optimized)
}
struct value *
-frame_unwind_register_value (struct frame_info *frame, int regnum)
+frame_unwind_register_value (frame_info *next_frame, int regnum)
{
struct gdbarch *gdbarch;
struct value *value;
- gdb_assert (frame != NULL);
- gdbarch = frame_unwind_arch (frame);
+ gdb_assert (next_frame != NULL);
+ gdbarch = frame_unwind_arch (next_frame);
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog,
"{ frame_unwind_register_value "
"(frame=%d,regnum=%d(%s),...) ",
- frame->level, regnum,
+ next_frame->level, regnum,
user_reg_map_regnum_to_name (gdbarch, regnum));
}
/* Find the unwinder. */
- if (frame->unwind == NULL)
- frame_unwind_find_by_frame (frame, &frame->prologue_cache);
+ if (next_frame->unwind == NULL)
+ frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache);
/* Ask this frame to unwind its register. */
- value = frame->unwind->prev_register (frame, &frame->prologue_cache, regnum);
+ value = next_frame->unwind->prev_register (next_frame,
+ &next_frame->prologue_cache,
+ regnum);
if (frame_debug)
{
}
LONGEST
-frame_unwind_register_signed (struct frame_info *frame, int regnum)
+frame_unwind_register_signed (frame_info *next_frame, int regnum)
{
- struct gdbarch *gdbarch = frame_unwind_arch (frame);
+ struct gdbarch *gdbarch = frame_unwind_arch (next_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int size = register_size (gdbarch, regnum);
- gdb_byte buf[MAX_REGISTER_SIZE];
+ struct value *value = frame_unwind_register_value (next_frame, regnum);
+
+ gdb_assert (value != NULL);
+
+ if (value_optimized_out (value))
+ {
+ throw_error (OPTIMIZED_OUT_ERROR,
+ _("Register %d was not saved"), regnum);
+ }
+ if (!value_entirely_available (value))
+ {
+ throw_error (NOT_AVAILABLE_ERROR,
+ _("Register %d is not available"), regnum);
+ }
+
+ LONGEST r = extract_signed_integer (value_contents_all (value), size,
+ byte_order);
- frame_unwind_register (frame, regnum, buf);
- return extract_signed_integer (buf, size, byte_order);
+ release_value (value);
+ return r;
}
LONGEST
}
ULONGEST
-frame_unwind_register_unsigned (struct frame_info *frame, int regnum)
+frame_unwind_register_unsigned (frame_info *next_frame, int regnum)
{
- struct gdbarch *gdbarch = frame_unwind_arch (frame);
+ struct gdbarch *gdbarch = frame_unwind_arch (next_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int size = register_size (gdbarch, regnum);
- gdb_byte buf[MAX_REGISTER_SIZE];
+ struct value *value = frame_unwind_register_value (next_frame, regnum);
+
+ gdb_assert (value != NULL);
- frame_unwind_register (frame, regnum, buf);
- return extract_unsigned_integer (buf, size, byte_order);
+ if (value_optimized_out (value))
+ {
+ throw_error (OPTIMIZED_OUT_ERROR,
+ _("Register %d was not saved"), regnum);
+ }
+ if (!value_entirely_available (value))
+ {
+ throw_error (NOT_AVAILABLE_ERROR,
+ _("Register %d is not available"), regnum);
+ }
+
+ ULONGEST r = extract_unsigned_integer (value_contents_all (value), size,
+ byte_order);
+
+ release_value (value);
+ return r;
}
ULONGEST
break;
}
case lval_register:
- regcache_cooked_write (get_current_regcache (), realnum, buf);
+ get_current_regcache ()->cooked_write (realnum, buf);
break;
default:
error (_("Attempt to assign to an unmodifiable value."));
/* Ensure that we will not read beyond the end of the register file.
This can only ever happen if the debug information is bad. */
maxsize = -offset;
- numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
+ numregs = gdbarch_num_cooked_regs (gdbarch);
for (i = regnum; i < numregs; i++)
{
int thissize = register_size (gdbarch, i);
}
else
{
- gdb_byte buf[MAX_REGISTER_SIZE];
- enum lval_type lval;
- CORE_ADDR addr;
- int realnum;
+ struct value *value = frame_unwind_register_value (frame->next,
+ regnum);
+ gdb_assert (value != NULL);
+ *optimizedp = value_optimized_out (value);
+ *unavailablep = !value_entirely_available (value);
- frame_register (frame, regnum, optimizedp, unavailablep,
- &lval, &addr, &realnum, buf);
if (*optimizedp || *unavailablep)
- return 0;
- memcpy (myaddr, buf + offset, curr_len);
+ {
+ release_value (value);
+ return 0;
+ }
+ memcpy (myaddr, value_contents_all (value) + offset, curr_len);
+ release_value (value);
}
myaddr += curr_len;
}
else
{
- gdb_byte buf[MAX_REGISTER_SIZE];
-
- deprecated_frame_register_read (frame, regnum, buf);
- memcpy (buf + offset, myaddr, curr_len);
- put_frame_register (frame, regnum, buf);
+ struct value *value = frame_unwind_register_value (frame->next,
+ regnum);
+ gdb_assert (value != NULL);
+
+ memcpy ((char *) value_contents_writeable (value) + offset, myaddr,
+ curr_len);
+ put_frame_register (frame, regnum, value_contents_raw (value));
+ release_value (value);
}
myaddr += curr_len;
frame->level = -1;
frame->pspace = pspace;
- frame->aspace = get_regcache_aspace (regcache);
+ frame->aspace = regcache->aspace ();
/* 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. */
/* 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. */
+ /* The sentinel frame has a special ID. */
frame->this_id.p = 1;
- frame->this_id.value = null_frame_id;
+ frame->this_id.value = sentinel_frame_id;
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> ");
return frame;
}
-/* Info about the innermost stack frame (contents of FP register). */
-
-static struct frame_info *current_frame;
-
/* Cache for frame addresses already read by gdb. Valid only while
inferior is stopped. Control variables for the frame cache should
be local to this module. */
return data;
}
-/* Return the innermost (currently executing) stack frame. This is
- split into two functions. The function unwind_to_current_frame()
- is wrapped in catch exceptions so that, even when the unwind of the
- sentinel frame fails, the function still returns a stack frame. */
-
-static int
-unwind_to_current_frame (struct ui_out *ui_out, void *args)
-{
- struct frame_info *frame = get_prev_frame (args);
-
- /* A sentinel frame can fail to unwind, e.g., because its PC value
- lands in somewhere like start. */
- if (frame == NULL)
- return 1;
- current_frame = frame;
- return 0;
-}
+static struct frame_info *get_prev_frame_always_1 (struct frame_info *this_frame);
struct frame_info *
get_current_frame (void)
{
+ struct frame_info *current_frame;
+
/* 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"
error (_("No memory."));
/* Traceframes are effectively a substitute for the live inferior. */
if (get_traceframe_number () < 0)
- {
- if (ptid_equal (inferior_ptid, null_ptid))
- error (_("No selected thread."));
- if (is_exited (inferior_ptid))
- error (_("Invalid selected thread."));
- if (is_executing (inferior_ptid))
- error (_("Target is executing."));
- }
+ validate_registers_access ();
+
+ if (sentinel_frame == NULL)
+ sentinel_frame =
+ create_sentinel_frame (current_program_space, get_current_regcache ());
+
+ /* Set the current frame before computing the frame id, to avoid
+ recursion inside compute_frame_id, in case the frame's
+ unwinder decides to do a symbol lookup (which depends on the
+ selected frame's block).
+
+ This call must always succeed. In particular, nothing inside
+ get_prev_frame_always_1 should try to unwind from the
+ sentinel frame, because that could fail/throw, and we always
+ want to leave with the current frame created and linked in --
+ we should never end up with the sentinel frame as outermost
+ frame. */
+ current_frame = get_prev_frame_always_1 (sentinel_frame);
+ gdb_assert (current_frame != NULL);
- if (current_frame == NULL)
- {
- struct frame_info *sentinel_frame =
- create_sentinel_frame (current_program_space, get_current_regcache ());
- if (catch_exceptions (current_uiout, unwind_to_current_frame,
- sentinel_frame, 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;
}
if (get_traceframe_number () < 0)
{
/* No current inferior, no frame. */
- if (ptid_equal (inferior_ptid, null_ptid))
+ if (inferior_ptid == null_ptid)
return 0;
+ thread_info *tp = inferior_thread ();
/* Don't try to read from a dead thread. */
- if (is_exited (inferior_ptid))
+ if (tp->state == THREAD_EXITED)
return 0;
/* ... or from a spinning thread. */
- if (is_executing (inferior_ptid))
+ if (tp->executing)
return 0;
}
selected_frame = fi;
/* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
frame is being invalidated. */
- if (deprecated_selected_frame_level_changed_hook)
- deprecated_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
return NULL;
}
+/* Return the frame that THIS_FRAME calls. If THIS_FRAME is the
+ innermost (i.e. current) frame, return the sentinel frame. Thus,
+ unlike get_next_frame(), NULL will never be returned. */
+
+struct frame_info *
+get_next_frame_sentinel_okay (struct frame_info *this_frame)
+{
+ gdb_assert (this_frame != NULL);
+
+ /* Note that, due to the manner in which the sentinel frame is
+ constructed, this_frame->next still works even when this_frame
+ is the sentinel frame. But we disallow it here anyway because
+ calling get_next_frame_sentinel_okay() on the sentinel frame
+ is likely a coding error. */
+ gdb_assert (this_frame != sentinel_frame);
+
+ return this_frame->next;
+}
+
/* Observer for the target_changed event. */
static void
struct frame_info *fi;
/* Tear down all frame caches. */
- for (fi = current_frame; fi != NULL; fi = fi->prev)
+ for (fi = sentinel_frame; fi != NULL; fi = fi->prev)
{
if (fi->prologue_cache && fi->unwind->dealloc_cache)
fi->unwind->dealloc_cache (fi, fi->prologue_cache);
obstack_free (&frame_cache_obstack, 0);
obstack_init (&frame_cache_obstack);
- if (current_frame != NULL)
+ if (sentinel_frame != NULL)
annotate_frames_invalid ();
- current_frame = NULL; /* Invalidate cache */
+ sentinel_frame = NULL; /* Invalidate cache */
select_frame (NULL);
frame_stash_invalidate ();
if (frame_debug)
}
}
-/* Called during frame unwinding to remove a previous frame pointer from a
- frame passed in ARG. */
-
-static void
-remove_prev_frame (void *arg)
-{
- struct frame_info *this_frame, *prev_frame;
-
- this_frame = (struct frame_info *) arg;
- prev_frame = this_frame->prev;
- gdb_assert (prev_frame != NULL);
-
- prev_frame->next = NULL;
- this_frame->prev = NULL;
-}
-
/* 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
get_prev_frame_if_no_cycle (struct frame_info *this_frame)
{
struct frame_info *prev_frame;
- struct cleanup *prev_frame_cleanup;
prev_frame = get_prev_frame_raw (this_frame);
- if (prev_frame == NULL)
- return NULL;
-
- /* The cleanup will remove the previous frame that get_prev_frame_raw
- linked onto THIS_FRAME. */
- prev_frame_cleanup = make_cleanup (remove_prev_frame, this_frame);
- compute_frame_id (prev_frame);
- if (!frame_stash_add (prev_frame))
+ /* Don't compute the frame id of the current frame yet. Unwinding
+ the sentinel frame can fail (e.g., if the thread is gone and we
+ can't thus read its registers). If we let the cycle detection
+ code below try to compute a frame ID, then an error thrown from
+ within the frame ID computation would result in the sentinel
+ frame as outermost frame, which is bogus. Instead, we'll compute
+ the current frame's ID lazily in get_frame_id. Note that there's
+ no point in doing cycle detection when there's only one frame, so
+ nothing is lost here. */
+ if (prev_frame->level == 0)
+ return prev_frame;
+
+ TRY
{
- /* Another frame with the same id was already in the stash. We just
- detected a cycle. */
- if (frame_debug)
+ compute_frame_id (prev_frame);
+ if (!frame_stash_add (prev_frame))
{
- fprintf_unfiltered (gdb_stdlog, "-> ");
- fprint_frame (gdb_stdlog, NULL);
- fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n");
+ /* 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;
+ prev_frame = NULL;
}
- this_frame->stop_reason = UNWIND_SAME_ID;
- /* Unlink. */
+ }
+ CATCH (ex, RETURN_MASK_ALL)
+ {
prev_frame->next = NULL;
this_frame->prev = NULL;
- prev_frame = NULL;
+
+ throw_exception (ex);
}
+ END_CATCH
- discard_cleanups (prev_frame_cleanup);
return prev_frame;
}
struct frame_info *
get_prev_frame_always (struct frame_info *this_frame)
{
- volatile struct gdb_exception ex;
struct frame_info *prev_frame = NULL;
- TRY_CATCH (ex, RETURN_MASK_ERROR)
+ TRY
{
prev_frame = get_prev_frame_always_1 (this_frame);
}
- if (ex.reason < 0)
+ CATCH (ex, RETURN_MASK_ERROR)
{
if (ex.error == MEMORY_ERROR)
{
pointer to the frame, this allows the STOP_STRING on the
frame to be of type 'const char *'. */
size = strlen (ex.message) + 1;
- stop_string = frame_obstack_zalloc (size);
+ stop_string = (char *) frame_obstack_zalloc (size);
memcpy (stop_string, ex.message, size);
this_frame->stop_string = stop_string;
}
else
throw_exception (ex);
}
+ END_CATCH
return prev_frame;
}
returned. */
maddr = gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame),
BMSYMBOL_VALUE_ADDRESS (msymbol),
- ¤t_target);
+ current_top_target ());
return maddr == get_frame_func (this_frame);
}
something should be calling get_selected_frame() or
get_current_frame(). */
gdb_assert (this_frame != NULL);
+
+ /* If this_frame is the current frame, then compute and stash
+ its frame id prior to fetching and computing the frame id of the
+ previous frame. Otherwise, the cycle detection code in
+ get_prev_frame_if_no_cycle() will not work correctly. When
+ get_frame_id() is called later on, an assertion error will
+ be triggered in the event of a cycle between the current
+ frame and its previous frame. */
+ if (this_frame->level == 0)
+ get_frame_id (this_frame);
+
frame_pc_p = get_frame_pc_if_available (this_frame, &frame_pc);
/* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
return get_prev_frame_always (this_frame);
}
+struct frame_id
+get_prev_frame_id_by_id (struct frame_id id)
+{
+ struct frame_id prev_id;
+ struct frame_info *frame;
+
+ frame = frame_find_by_id (id);
+
+ if (frame != NULL)
+ prev_id = get_frame_id (get_prev_frame (frame));
+ else
+ prev_id = null_frame_id;
+
+ return prev_id;
+}
+
CORE_ADDR
get_frame_pc (struct frame_info *frame)
{
int
get_frame_pc_if_available (struct frame_info *frame, CORE_ADDR *pc)
{
- volatile struct gdb_exception ex;
gdb_assert (frame->next != NULL);
- TRY_CATCH (ex, RETURN_MASK_ERROR)
+ TRY
{
*pc = frame_unwind_pc (frame->next);
}
- if (ex.reason < 0)
+ CATCH (ex, RETURN_MASK_ERROR)
{
if (ex.error == NOT_AVAILABLE_ERROR)
return 0;
else
throw_exception (ex);
}
+ END_CATCH
return 1;
}
get_frame_address_in_block_if_available (struct frame_info *this_frame,
CORE_ADDR *pc)
{
- volatile struct gdb_exception ex;
- TRY_CATCH (ex, RETURN_MASK_ERROR)
+ TRY
{
*pc = get_frame_address_in_block (this_frame);
}
- if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR)
- return 0;
- else if (ex.reason < 0)
- throw_exception (ex);
- else
- return 1;
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (ex.error == NOT_AVAILABLE_ERROR)
+ return 0;
+ throw_exception (ex);
+ }
+ END_CATCH
+
+ return 1;
}
-void
-find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
+symtab_and_line
+find_frame_sal (frame_info *frame)
{
struct frame_info *next_frame;
int notcurrent;
if (next_frame)
sym = get_frame_function (next_frame);
else
- sym = inline_skipped_symbol (inferior_ptid);
+ sym = inline_skipped_symbol (inferior_thread ());
/* If frame is inline, it certainly has symbols. */
gdb_assert (sym);
- init_sal (sal);
+
+ symtab_and_line sal;
if (SYMBOL_LINE (sym) != 0)
{
- sal->symtab = symbol_symtab (sym);
- sal->line = SYMBOL_LINE (sym);
+ sal.symtab = symbol_symtab (sym);
+ sal.line = SYMBOL_LINE (sym);
}
else
/* If the symbol does not have a location, we don't know where
the call site is. Do not pretend to. This is jarring, but
we can't do much better. */
- sal->pc = get_frame_pc (frame);
+ sal.pc = get_frame_pc (frame);
- sal->pspace = get_frame_program_space (frame);
-
- return;
+ sal.pspace = get_frame_program_space (frame);
+ return sal;
}
/* If FRAME is not the innermost frame, that normally means that
instruction/line, consequently, for such cases, want to get the
line containing fi->pc. */
if (!get_frame_pc_if_available (frame, &pc))
- {
- init_sal (sal);
- return;
- }
+ return {};
notcurrent = (pc != get_frame_address_in_block (frame));
- (*sal) = find_pc_line (pc, notcurrent);
+ return find_pc_line (pc, notcurrent);
}
/* Per "frame.h", return the ``address'' of the frame. Code should
return this_frame->pspace;
}
-struct address_space *
+const address_space *
get_frame_address_space (struct frame_info *frame)
{
return frame->aspace;
struct gdbarch *
frame_unwind_caller_arch (struct frame_info *next_frame)
{
- return frame_unwind_arch (skip_artificial_frames (next_frame));
+ next_frame = skip_artificial_frames (next_frame);
+
+ /* We must have a non-artificial frame. The caller is supposed to check
+ the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID
+ in this case. */
+ gdb_assert (next_frame != NULL);
+
+ return frame_unwind_arch (next_frame);
+}
+
+/* Gets the language of FRAME. */
+
+enum language
+get_frame_language (struct frame_info *frame)
+{
+ CORE_ADDR pc = 0;
+ int pc_p = 0;
+
+ gdb_assert (frame!= NULL);
+
+ /* We determine the current frame language by looking up its
+ associated symtab. To retrieve this symtab, we use the frame
+ PC. However we cannot use the frame PC as is, because it
+ usually points to the instruction following the "call", which
+ is sometimes the first instruction of another function. So
+ we rely on get_frame_address_in_block(), it provides us with
+ a PC that is guaranteed to be inside the frame's code
+ block. */
+
+ TRY
+ {
+ pc = get_frame_address_in_block (frame);
+ pc_p = 1;
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (ex.error != NOT_AVAILABLE_ERROR)
+ throw_exception (ex);
+ }
+ END_CATCH
+
+ if (pc_p)
+ {
+ struct compunit_symtab *cust = find_pc_compunit_symtab (pc);
+
+ if (cust != NULL)
+ return compunit_language (cust);
+ }
+
+ return language_unknown;
}
/* Stack pointer methods. */
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
- /* Normality - an architecture that provides a way of obtaining any
- frame inner-most address. */
- if (gdbarch_unwind_sp_p (gdbarch))
- /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to
- operate on THIS_FRAME now. */
- return gdbarch_unwind_sp (gdbarch, this_frame->next);
- /* Now things are really are grim. Hope that the value returned by
- the gdbarch_sp_regnum register is meaningful. */
- if (gdbarch_sp_regnum (gdbarch) >= 0)
- return get_frame_register_unsigned (this_frame,
- gdbarch_sp_regnum (gdbarch));
- internal_error (__FILE__, __LINE__, _("Missing unwind SP method"));
+ /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to
+ operate on THIS_FRAME now. */
+ return gdbarch_unwind_sp (gdbarch, this_frame->next);
}
/* Return the reason why we can't unwind past FRAME. */
/* Clean up after a failed (wrong unwinder) attempt to unwind past
FRAME. */
-static void
-frame_cleanup_after_sniffer (void *arg)
+void
+frame_cleanup_after_sniffer (struct frame_info *frame)
{
- struct frame_info *frame = arg;
-
/* The sniffer should not allocate a prologue cache if it did not
match this frame. */
gdb_assert (frame->prologue_cache == NULL);
}
/* Set FRAME's unwinder temporarily, so that we can call a sniffer.
- Return a cleanup which should be called if unwinding fails, and
- discarded if it succeeds. */
+ If sniffing fails, the caller should be sure to call
+ frame_cleanup_after_sniffer. */
-struct cleanup *
+void
frame_prepare_for_sniffer (struct frame_info *frame,
const struct frame_unwind *unwind)
{
gdb_assert (frame->unwind == NULL);
frame->unwind = unwind;
- return make_cleanup (frame_cleanup_after_sniffer, frame);
}
-extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
-
static struct cmd_list_element *set_backtrace_cmdlist;
static struct cmd_list_element *show_backtrace_cmdlist;
static void
-set_backtrace_cmd (char *args, int from_tty)
+set_backtrace_cmd (const char *args, int from_tty)
{
help_list (set_backtrace_cmdlist, "set backtrace ", all_commands,
gdb_stdout);
}
static void
-show_backtrace_cmd (char *args, int from_tty)
+show_backtrace_cmd (const char *args, int from_tty)
{
cmd_show_list (show_backtrace_cmdlist, from_tty, "");
}
frame_stash_create ();
- observer_attach_target_changed (frame_observer_target_changed);
+ gdb::observers::target_changed.attach (frame_observer_target_changed);
add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\
Set backtrace specific variables.\n\