#include "observer.h"
#include "objfiles.h"
#include "exceptions.h"
+#include "gdbthread.h"
static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
/* Flag to control debugging. */
-static int frame_debug;
+int frame_debug;
static void
show_frame_debug (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
fi->level);
/* Find the unwinder. */
if (fi->unwind == NULL)
- fi->unwind = frame_unwind_find_by_frame (fi->next,
- &fi->prologue_cache);
+ fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache);
/* Find THIS frame's ID. */
- fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
+ fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value);
fi->this_id.p = 1;
if (frame_debug)
{
return eq;
}
-int
+/* Safety net to check whether frame ID L should be inner to
+ frame ID R, according to their stack addresses.
+
+ This method cannot be used to compare arbitrary frames, as the
+ ranges of valid stack addresses may be discontiguous (e.g. due
+ to sigaltstack).
+
+ However, it can be used as safety net to discover invalid frame
+ IDs in certain circumstances.
+
+ * If frame NEXT is the immediate inner frame to THIS, and NEXT
+ is a NORMAL frame, then the stack address of NEXT must be
+ inner-than-or-equal to the stack address of THIS.
+
+ Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind
+ error has occurred.
+
+ * If frame NEXT is the immediate inner frame to THIS, and NEXT
+ is a NORMAL frame, and NEXT and THIS have different stack
+ addresses, no other frame in the frame chain may have a stack
+ address in between.
+
+ Therefore, if frame_id_inner (TEST, THIS) holds, but
+ frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer
+ to a valid frame in the frame chain. */
+
+static int
frame_id_inner (struct gdbarch *gdbarch, struct frame_id l, struct frame_id r)
{
int inner;
struct frame_info *
frame_find_by_id (struct frame_id id)
{
- struct frame_info *frame;
+ struct frame_info *frame, *prev_frame;
/* ZERO denotes the null frame, let the caller decide what to do
about it. Should it instead return get_current_frame()? */
if (!frame_id_p (id))
return NULL;
- for (frame = get_current_frame ();
- frame != NULL;
- frame = get_prev_frame (frame))
+ for (frame = get_current_frame (); ; frame = prev_frame)
{
struct frame_id this = get_frame_id (frame);
if (frame_id_eq (id, this))
/* An exact match. */
return frame;
- if (frame_id_inner (get_frame_arch (frame), id, this))
- /* Gone to far. */
+
+ prev_frame = get_prev_frame (frame);
+ if (!prev_frame)
+ return NULL;
+
+ /* As a safety net to avoid unnecessary backtracing while trying
+ to find an invalid ID, we check for a common situation where
+ we can detect from comparing stack addresses that no other
+ frame in the current frame chain can have this ID. See the
+ comment at frame_id_inner for details. */
+ if (get_frame_type (frame) == NORMAL_FRAME
+ && !frame_id_inner (get_frame_arch (frame), id, this)
+ && frame_id_inner (get_frame_arch (prev_frame), id,
+ get_frame_id (prev_frame)))
return NULL;
- /* Either we're not yet gone far enough out along the frame
- chain (inner(this,id)), or we're comparing frameless functions
- (same .base, different .func, no test available). Struggle
- on until we've definitly gone to far. */
}
return NULL;
}
if (!this_frame->prev_pc.p)
{
CORE_ADDR pc;
- if (this_frame->unwind == NULL)
- this_frame->unwind
- = frame_unwind_find_by_frame (this_frame->next,
- &this_frame->prologue_cache);
- if (this_frame->unwind->prev_pc != NULL)
- /* A per-frame unwinder, prefer it. */
- pc = this_frame->unwind->prev_pc (this_frame->next,
- &this_frame->prologue_cache);
- else if (gdbarch_unwind_pc_p (get_frame_arch (this_frame)))
+ if (gdbarch_unwind_pc_p (get_frame_arch (this_frame)))
{
/* The right way. The `pure' way. The one true way. This
method depends solely on the register-unwind code to
}
CORE_ADDR
-frame_func_unwind (struct frame_info *fi, enum frame_type this_type)
+get_frame_func (struct frame_info *this_frame)
{
- if (!fi->prev_func.p)
+ struct frame_info *next_frame = this_frame->next;
+
+ if (!next_frame->prev_func.p)
{
/* Make certain that this, and not the adjacent, function is
found. */
- CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi, this_type);
- fi->prev_func.p = 1;
- fi->prev_func.addr = get_pc_function_start (addr_in_block);
+ CORE_ADDR addr_in_block = get_frame_address_in_block (this_frame);
+ next_frame->prev_func.p = 1;
+ next_frame->prev_func.addr = get_pc_function_start (addr_in_block);
if (frame_debug)
fprintf_unfiltered (gdb_stdlog,
- "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
- fi->level, paddr_nz (fi->prev_func.addr));
+ "{ get_frame_func (this_frame=%d) -> 0x%s }\n",
+ this_frame->level,
+ paddr_nz (next_frame->prev_func.addr));
}
- return fi->prev_func.addr;
-}
-
-CORE_ADDR
-get_frame_func (struct frame_info *fi)
-{
- return frame_func_unwind (fi->next, get_frame_type (fi));
+ return next_frame->prev_func.addr;
}
static int
do_frame_register_read (void *src, int regnum, gdb_byte *buf)
{
- frame_register_read (src, regnum, buf);
- return 1;
+ return frame_register_read (src, regnum, buf);
}
struct regcache *
scratch = frame_save_as_regcache (prev_frame);
cleanups = make_cleanup_regcache_xfree (scratch);
+ /* If we are popping a dummy frame, clean up the associated
+ data as well. */
+ if (get_frame_type (this_frame) == DUMMY_FRAME)
+ dummy_frame_pop (get_frame_id (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
int *optimizedp, enum lval_type *lvalp,
CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
{
- struct frame_unwind_cache *cache;
-
- if (frame_debug)
- {
- fprintf_unfiltered (gdb_stdlog, "\
-{ frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
- frame->level, regnum,
- frame_map_regnum_to_name (frame, regnum));
- }
+ struct value *value;
/* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
that the value proper does not need to be fetched. */
gdb_assert (realnump != NULL);
/* gdb_assert (bufferp != NULL); */
- /* 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 a frame, there is some pretty busted code as it should have
- detected the problem before calling here. */
- gdb_assert (frame != NULL);
+ value = frame_unwind_register_value (frame, regnum);
- /* Find the unwinder. */
- if (frame->unwind == NULL)
- frame->unwind = frame_unwind_find_by_frame (frame->next,
- &frame->prologue_cache);
+ gdb_assert (value != NULL);
- /* Ask this frame to unwind its register. See comment in
- "frame-unwind.h" for why NEXT frame and this unwind cache are
- passed in. */
- frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
- optimizedp, lvalp, addrp, realnump, bufferp);
+ *optimizedp = value_optimized_out (value);
+ *lvalp = VALUE_LVAL (value);
+ *addrp = VALUE_ADDRESS (value);
+ *realnump = VALUE_REGNUM (value);
- 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 unsigned char *buf = bufferp;
- fprintf_unfiltered (gdb_stdlog, "[");
- for (i = 0; i < register_size (get_frame_arch (frame), regnum); i++)
- fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
- fprintf_unfiltered (gdb_stdlog, "]");
- }
- fprintf_unfiltered (gdb_stdlog, " }\n");
- }
+ if (bufferp)
+ memcpy (bufferp, value_contents_all (value),
+ TYPE_LENGTH (value_type (value)));
+
+ /* Dispose of the new value. This prevents watchpoints from
+ trying to watch the saved frame pointer. */
+ release_value (value);
+ value_free (value);
}
void
frame_unwind_register (frame->next, regnum, buf);
}
+struct value *
+frame_unwind_register_value (struct frame_info *frame, int regnum)
+{
+ struct value *value;
+
+ gdb_assert (frame != NULL);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "\
+{ frame_unwind_register_value (frame=%d,regnum=%d(%s),...) ",
+ frame->level, regnum,
+ user_reg_map_regnum_to_name
+ (get_frame_arch (frame), regnum));
+ }
+
+ /* Find the unwinder. */
+ if (frame->unwind == NULL)
+ frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache);
+
+ /* Ask this frame to unwind its register. */
+ value = frame->unwind->prev_register (frame, &frame->prologue_cache, regnum);
+
+ if (frame_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "->");
+ if (value_optimized_out (value))
+ fprintf_unfiltered (gdb_stdlog, " optimized out");
+ else
+ {
+ if (VALUE_LVAL (value) == lval_register)
+ fprintf_unfiltered (gdb_stdlog, " register=%d",
+ VALUE_REGNUM (value));
+ else if (VALUE_LVAL (value) == lval_memory)
+ fprintf_unfiltered (gdb_stdlog, " address=0x%s",
+ paddr_nz (VALUE_ADDRESS (value)));
+ else
+ fprintf_unfiltered (gdb_stdlog, " computed");
+
+ if (value_lazy (value))
+ fprintf_unfiltered (gdb_stdlog, " lazy");
+ else
+ {
+ int i;
+ const gdb_byte *buf = value_contents (value);
+
+ fprintf_unfiltered (gdb_stdlog, " bytes=");
+ fprintf_unfiltered (gdb_stdlog, "[");
+ for (i = 0; i < register_size (get_frame_arch (frame), regnum); i++)
+ fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
+ fprintf_unfiltered (gdb_stdlog, "]");
+ }
+ }
+
+ fprintf_unfiltered (gdb_stdlog, " }\n");
+ }
+
+ return value;
+}
+
+struct value *
+get_frame_register_value (struct frame_info *frame, int regnum)
+{
+ return frame_unwind_register_value (frame->next, regnum);
+}
+
LONGEST
frame_unwind_register_signed (struct frame_info *frame, int regnum)
{
}
}
-/* Map between a frame register number and its name. A frame register
- space is a superset of the cooked register space --- it also
- includes builtin registers. */
-
-int
-frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len)
-{
- return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len);
-}
-
-const char *
-frame_map_regnum_to_name (struct frame_info *frame, int regnum)
-{
- return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum);
-}
-
/* Create a sentinel frame. */
static struct frame_info *
error (_("No stack."));
if (!target_has_memory)
error (_("No memory."));
+ if (is_executing (inferior_ptid))
+ error (_("Target is executing."));
+
if (current_frame == NULL)
{
struct frame_info *sentinel_frame =
static struct frame_info *selected_frame;
+static int
+has_stack_frames (void)
+{
+ if (!target_has_registers || !target_has_stack || !target_has_memory)
+ return 0;
+
+ /* If the current thread is executing, don't try to read from
+ it. */
+ if (is_executing (inferior_ptid))
+ return 0;
+
+ return 1;
+}
+
/* 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. */
{
if (selected_frame == NULL)
{
- if (message != NULL && (!target_has_registers
- || !target_has_stack
- || !target_has_memory))
+ if (message != NULL && !has_stack_frames ())
error (("%s"), message);
/* Hey! Don't trust this. It should really be re-finding the
last selected frame of the currently selected thread. This,
struct frame_info *
deprecated_safe_get_selected_frame (void)
{
- if (!target_has_registers || !target_has_stack || !target_has_memory)
+ if (!has_stack_frames ())
return NULL;
return get_selected_frame (NULL);
}
/* Select/initialize both the unwind function and the frame's type
based on the PC. */
- fi->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
+ fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache);
fi->this_id.p = 1;
deprecated_update_frame_base_hack (fi, addr);
}
return this_frame->prev;
}
+
+ /* If the frame unwinder hasn't been selected yet, we must do so
+ before setting prev_p; otherwise the check for misbehaved
+ sniffers will think that this frame's sniffer tried to unwind
+ further (see frame_cleanup_after_sniffer). */
+ if (this_frame->unwind == NULL)
+ this_frame->unwind
+ = frame_unwind_find_by_frame (this_frame, &this_frame->prologue_cache);
+
this_frame->prev_p = 1;
this_frame->stop_reason = UNWIND_NO_REASON;
/* Check that this frame's ID isn't inner to (younger, below, next)
the next frame. This happens when a frame unwind goes backwards.
- Exclude signal trampolines (due to sigaltstack the frame ID can
- go backwards) and sentinel frames (the test is meaningless). */
- if (this_frame->next->level >= 0
- && this_frame->next->unwind->type != SIGTRAMP_FRAME
- && frame_id_inner (get_frame_arch (this_frame), this_id,
+ This check is valid only if the next frame is NORMAL. See the
+ comment at frame_id_inner for details. */
+ if (this_frame->next->unwind->type == NORMAL_FRAME
+ && frame_id_inner (get_frame_arch (this_frame->next), this_id,
get_frame_id (this_frame->next)))
{
if (frame_debug)
return frame_pc_unwind (frame->next);
}
-/* Return an address that falls within NEXT_FRAME's caller's code
- block, assuming that the caller is a THIS_TYPE frame. */
+/* Return an address that falls within THIS_FRAME's code block. */
CORE_ADDR
-frame_unwind_address_in_block (struct frame_info *next_frame,
- enum frame_type this_type)
+get_frame_address_in_block (struct frame_info *this_frame)
{
/* A draft address. */
- CORE_ADDR pc = frame_pc_unwind (next_frame);
-
- /* If NEXT_FRAME was called by a signal frame or dummy frame, then
- we shold not adjust the unwound PC. These frames may not call
- their next frame in the normal way; the operating system or GDB
- may have pushed their resume address manually onto the stack, so
- it may be the very first instruction. Even if the resume address
- was not manually pushed, they expect to be returned to. */
- if (this_type != NORMAL_FRAME)
- return pc;
-
- /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
- and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
- frame's PC ends up pointing at the instruction fallowing the
- "call". Adjust that PC value so that it falls on the call
- instruction (which, hopefully, falls within THIS frame's code
- block). So far it's proved to be a very good approximation. See
- get_frame_type() for why ->type can't be used. */
- if (next_frame->level >= 0
- && get_frame_type (next_frame) == NORMAL_FRAME)
- --pc;
- return pc;
-}
+ CORE_ADDR pc = get_frame_pc (this_frame);
+
+ struct frame_info *next_frame = this_frame->next;
+
+ /* Calling get_frame_pc returns the resume address for THIS_FRAME.
+ Normally the resume address is inside the body of the function
+ associated with THIS_FRAME, but there is a special case: when
+ calling a function which the compiler knows will never return
+ (for instance abort), the call may be the very last instruction
+ in the calling function. The resume address will point after the
+ call and may be at the beginning of a different function
+ entirely.
+
+ If THIS_FRAME is a signal frame or dummy frame, then we should
+ not adjust the unwound PC. For a dummy frame, GDB pushed the
+ resume address manually onto the stack. For a signal frame, the
+ OS may have pushed the resume address manually and invoked the
+ handler (e.g. GNU/Linux), or invoked the trampoline which called
+ the signal handler - but in either case the signal handler is
+ expected to return to the trampoline. So in both of these
+ cases we know that the resume address is executable and
+ related. So we only need to adjust the PC if THIS_FRAME
+ is a normal function.
+
+ If the program has been interrupted while THIS_FRAME is current,
+ then clearly the resume address is inside the associated
+ function. There are three kinds of interruption: debugger stop
+ (next frame will be SENTINEL_FRAME), operating system
+ signal or exception (next frame will be SIGTRAMP_FRAME),
+ or debugger-induced function call (next frame will be
+ DUMMY_FRAME). So we only need to adjust the PC if
+ NEXT_FRAME is a normal function.
+
+ We check the type of NEXT_FRAME first, since it is already
+ known; frame type is determined by the unwinder, and since
+ we have THIS_FRAME we've already selected an unwinder for
+ NEXT_FRAME. */
+ if (get_frame_type (next_frame) == NORMAL_FRAME
+ && get_frame_type (this_frame) == NORMAL_FRAME)
+ return pc - 1;
-CORE_ADDR
-get_frame_address_in_block (struct frame_info *this_frame)
-{
- return frame_unwind_address_in_block (this_frame->next,
- get_frame_type (this_frame));
+ return pc;
}
static int
if (get_frame_type (fi) != NORMAL_FRAME)
return 0;
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (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);
+ return fi->base->this_base (fi, &fi->prologue_cache);
+ return fi->base->this_base (fi, &fi->base_cache);
}
CORE_ADDR
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (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);
+ return fi->base->this_locals (fi, &fi->prologue_cache);
+ return fi->base->this_locals (fi, &fi->base_cache);
}
CORE_ADDR
return 0;
/* If there isn't a frame address method, find it. */
if (fi->base == NULL)
- fi->base = frame_base_find_by_frame (fi->next);
+ fi->base = frame_base_find_by_frame (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);
+ return fi->base->this_args (fi, &fi->prologue_cache);
+ return fi->base->this_args (fi, &fi->base_cache);
}
/* Level of the selected frame: 0 for innermost, 1 for its caller, ...
if (frame->unwind == NULL)
/* Initialize the frame's unwinder because that's what
provides the frame's type. */
- frame->unwind = frame_unwind_find_by_frame (frame->next,
- &frame->prologue_cache);
+ frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache);
return frame->unwind->type;
}
CORE_ADDR
get_frame_sp (struct frame_info *this_frame)
{
- return frame_sp_unwind (this_frame->next);
-}
-
-CORE_ADDR
-frame_sp_unwind (struct frame_info *next_frame)
-{
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
+ 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))
- return gdbarch_unwind_sp (gdbarch, next_frame);
+ /* 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 frame_unwind_register_unsigned (next_frame,
- gdbarch_sp_regnum (gdbarch));
+ return get_frame_register_unsigned (this_frame,
+ gdbarch_sp_regnum (gdbarch));
internal_error (__FILE__, __LINE__, _("Missing unwind SP method"));
}
}
}
+/* Clean up after a failed (wrong unwinder) attempt to unwind past
+ FRAME. */
+
+static void
+frame_cleanup_after_sniffer (void *arg)
+{
+ 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);
+
+ /* No sniffer should extend the frame chain; sniff based on what is
+ already certain. */
+ gdb_assert (!frame->prev_p);
+
+ /* The sniffer should not check the frame's ID; that's circular. */
+ gdb_assert (!frame->this_id.p);
+
+ /* Clear cached fields dependent on the unwinder.
+
+ The previous PC is independent of the unwinder, but the previous
+ function is not (see get_frame_address_in_block). */
+ frame->prev_func.p = 0;
+ frame->prev_func.addr = 0;
+
+ /* Discard the unwinder last, so that we can easily find it if an assertion
+ in this function triggers. */
+ frame->unwind = 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. */
+
+struct cleanup *
+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;
projects / deliverable / binutils-gdb.git / blobdiff