/* Definitions for frame unwinder, for GDB, the GNU debugger.
- Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 2003-2022 Free Software Foundation, Inc.
This file is part of GDB.
#include "inline-frame.h"
#include "value.h"
#include "regcache.h"
-
-#include "gdb_assert.h"
-#include "gdb_obstack.h"
-
-static struct gdbarch_data *frame_unwind_data;
+#include "gdbsupport/gdb_obstack.h"
+#include "target.h"
+#include "gdbarch.h"
+#include "dwarf2/frame-tailcall.h"
struct frame_unwind_table_entry
{
struct frame_unwind_table
{
- struct frame_unwind_table_entry *list;
+ struct frame_unwind_table_entry *list = nullptr;
/* The head of the OSABI part of the search list. */
- struct frame_unwind_table_entry **osabi_head;
+ struct frame_unwind_table_entry **osabi_head = nullptr;
};
-static void *
-frame_unwind_init (struct obstack *obstack)
+static const registry<gdbarch>::key<struct frame_unwind_table>
+ frame_unwind_data;
+
+/* A helper function to add an unwinder to a list. LINK says where to
+ install the new unwinder. The new link is returned. */
+
+static struct frame_unwind_table_entry **
+add_unwinder (struct obstack *obstack, const struct frame_unwind *unwinder,
+ struct frame_unwind_table_entry **link)
{
- struct frame_unwind_table *table
- = OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
+ *link = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
+ (*link)->unwinder = unwinder;
+ return &(*link)->next;
+}
+
+static struct frame_unwind_table *
+get_frame_unwind_table (struct gdbarch *gdbarch)
+{
+ struct frame_unwind_table *table = frame_unwind_data.get (gdbarch);
+ if (table != nullptr)
+ return table;
+
+ table = new frame_unwind_table;
+
/* Start the table out with a few default sniffers. OSABI code
can't override this. */
- table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
- table->list->unwinder = dummy_frame_unwind;
- table->list->next = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
- table->list->next->unwinder = inline_frame_unwind;
+ struct frame_unwind_table_entry **link = &table->list;
+
+ struct obstack *obstack = gdbarch_obstack (gdbarch);
+ link = add_unwinder (obstack, &dummy_frame_unwind, link);
+ /* The DWARF tailcall sniffer must come before the inline sniffer.
+ Otherwise, we can end up in a situation where a DWARF frame finds
+ tailcall information, but then the inline sniffer claims a frame
+ before the tailcall sniffer, resulting in confusion. This is
+ safe to do always because the tailcall sniffer can only ever be
+ activated if the newer frame was created using the DWARF
+ unwinder, and it also found tailcall information. */
+ link = add_unwinder (obstack, &dwarf2_tailcall_frame_unwind, link);
+ link = add_unwinder (obstack, &inline_frame_unwind, link);
+
/* The insertion point for OSABI sniffers. */
- table->osabi_head = &table->list->next->next;
+ table->osabi_head = link;
+ frame_unwind_data.set (gdbarch, table);
+
return table;
}
frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
const struct frame_unwind *unwinder)
{
- struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
+ struct frame_unwind_table *table = get_frame_unwind_table (gdbarch);
struct frame_unwind_table_entry *entry;
/* Insert the new entry at the start of the list. */
frame_unwind_append_unwinder (struct gdbarch *gdbarch,
const struct frame_unwind *unwinder)
{
- struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
+ struct frame_unwind_table *table = get_frame_unwind_table (gdbarch);
struct frame_unwind_table_entry **ip;
/* Find the end of the list and insert the new entry there. */
(*ip)->unwinder = unwinder;
}
-const struct frame_unwind *
-frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache)
+/* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for
+ THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME
+ unchanged and returns 0. */
+
+static int
+frame_unwind_try_unwinder (frame_info_ptr this_frame, void **this_cache,
+ const struct frame_unwind *unwinder)
{
- int i;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
- struct frame_unwind_table_entry *entry;
- struct cleanup *old_cleanup;
- for (entry = table->list; entry != NULL; entry = entry->next)
+ int res = 0;
+
+ unsigned int entry_generation = get_frame_cache_generation ();
+
+ frame_prepare_for_sniffer (this_frame, unwinder);
+
+ try
+ {
+ frame_debug_printf ("trying unwinder \"%s\"", unwinder->name);
+ res = unwinder->sniffer (unwinder, this_frame, this_cache);
+ }
+ catch (const gdb_exception &ex)
{
- struct cleanup *old_cleanup;
+ frame_debug_printf ("caught exception: %s", ex.message->c_str ());
- old_cleanup = frame_prepare_for_sniffer (this_frame, entry->unwinder);
- if (entry->unwinder->sniffer (entry->unwinder, this_frame,
- this_cache))
+ /* Catch all exceptions, caused by either interrupt or error.
+ Reset *THIS_CACHE, unless something reinitialized the frame
+ cache meanwhile, in which case THIS_FRAME/THIS_CACHE are now
+ dangling. */
+ if (get_frame_cache_generation () == entry_generation)
{
- discard_cleanups (old_cleanup);
- return entry->unwinder;
+ *this_cache = NULL;
+ frame_cleanup_after_sniffer (this_frame);
}
- do_cleanups (old_cleanup);
+
+ if (ex.error == NOT_AVAILABLE_ERROR)
+ {
+ /* This usually means that not even the PC is available,
+ thus most unwinders aren't able to determine if they're
+ the best fit. Keep trying. Fallback prologue unwinders
+ should always accept the frame. */
+ return 0;
+ }
+ throw;
}
- internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed"));
+
+ if (res)
+ {
+ frame_debug_printf ("yes");
+ return 1;
+ }
+ else
+ {
+ frame_debug_printf ("no");
+ /* Don't set *THIS_CACHE to NULL here, because sniffer has to do
+ so. */
+ frame_cleanup_after_sniffer (this_frame);
+ return 0;
+ }
+ gdb_assert_not_reached ("frame_unwind_try_unwinder");
+}
+
+/* Iterate through sniffers for THIS_FRAME frame until one returns with an
+ unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set
+ by this function. Possibly initialize THIS_CACHE. */
+
+void
+frame_unwind_find_by_frame (frame_info_ptr this_frame, void **this_cache)
+{
+ FRAME_SCOPED_DEBUG_ENTER_EXIT;
+ frame_debug_printf ("this_frame=%d", frame_relative_level (this_frame));
+
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct frame_unwind_table *table = get_frame_unwind_table (gdbarch);
+ struct frame_unwind_table_entry *entry;
+ const struct frame_unwind *unwinder_from_target;
+
+ unwinder_from_target = target_get_unwinder ();
+ if (unwinder_from_target != NULL
+ && frame_unwind_try_unwinder (this_frame, this_cache,
+ unwinder_from_target))
+ return;
+
+ unwinder_from_target = target_get_tailcall_unwinder ();
+ if (unwinder_from_target != NULL
+ && frame_unwind_try_unwinder (this_frame, this_cache,
+ unwinder_from_target))
+ return;
+
+ for (entry = table->list; entry != NULL; entry = entry->next)
+ if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder))
+ return;
+
+ internal_error (_("frame_unwind_find_by_frame failed"));
}
/* A default frame sniffer which always accepts the frame. Used by
int
default_frame_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame,
+ frame_info_ptr this_frame,
void **this_prologue_cache)
{
return 1;
}
+/* The default frame unwinder stop_reason callback. */
+
+enum unwind_stop_reason
+default_frame_unwind_stop_reason (frame_info_ptr this_frame,
+ void **this_cache)
+{
+ struct frame_id this_id = get_frame_id (this_frame);
+
+ if (this_id == outer_frame_id)
+ return UNWIND_OUTERMOST;
+ else
+ return UNWIND_NO_REASON;
+}
+
+/* See frame-unwind.h. */
+
+CORE_ADDR
+default_unwind_pc (struct gdbarch *gdbarch, frame_info_ptr next_frame)
+{
+ int pc_regnum = gdbarch_pc_regnum (gdbarch);
+ CORE_ADDR pc = frame_unwind_register_unsigned (next_frame, pc_regnum);
+ pc = gdbarch_addr_bits_remove (gdbarch, pc);
+ return pc;
+}
+
+/* See frame-unwind.h. */
+
+CORE_ADDR
+default_unwind_sp (struct gdbarch *gdbarch, frame_info_ptr next_frame)
+{
+ int sp_regnum = gdbarch_sp_regnum (gdbarch);
+ return frame_unwind_register_unsigned (next_frame, sp_regnum);
+}
+
/* Helper functions for value-based register unwinding. These return
a (possibly lazy) value of the appropriate type. */
/* Return a value which indicates that FRAME did not save REGNUM. */
struct value *
-frame_unwind_got_optimized (struct frame_info *frame, int regnum)
+frame_unwind_got_optimized (frame_info_ptr frame, int regnum)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
- struct value *reg_val;
+ struct type *type = register_type (gdbarch, regnum);
- reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
- set_value_optimized_out (reg_val, 1);
- return reg_val;
+ return allocate_optimized_out_value (type);
}
/* Return a value which indicates that FRAME copied REGNUM into
register NEW_REGNUM. */
struct value *
-frame_unwind_got_register (struct frame_info *frame, int regnum, int new_regnum)
+frame_unwind_got_register (frame_info_ptr frame,
+ int regnum, int new_regnum)
{
return value_of_register_lazy (frame, new_regnum);
}
ADDR. */
struct value *
-frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr)
+frame_unwind_got_memory (frame_info_ptr frame, int regnum, CORE_ADDR addr)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr);
REGNUM has a known constant (computed) value of VAL. */
struct value *
-frame_unwind_got_constant (struct frame_info *frame, int regnum,
+frame_unwind_got_constant (frame_info_ptr frame, int regnum,
ULONGEST val)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
struct value *reg_val;
reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
- store_unsigned_integer (value_contents_writeable (reg_val),
+ store_unsigned_integer (value_contents_writeable (reg_val).data (),
register_size (gdbarch, regnum), byte_order, val);
return reg_val;
}
struct value *
-frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf)
+frame_unwind_got_bytes (frame_info_ptr frame, int regnum, const gdb_byte *buf)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
struct value *reg_val;
reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
- memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum));
+ memcpy (value_contents_raw (reg_val).data (), buf,
+ register_size (gdbarch, regnum));
return reg_val;
}
CORE_ADDR to a target address if necessary. */
struct value *
-frame_unwind_got_address (struct frame_info *frame, int regnum,
+frame_unwind_got_address (frame_info_ptr frame, int regnum,
CORE_ADDR addr)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
struct value *reg_val;
reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
- pack_long (value_contents_writeable (reg_val),
+ pack_long (value_contents_writeable (reg_val).data (),
register_type (gdbarch, regnum), addr);
return reg_val;
}
-
-extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
-
-void
-_initialize_frame_unwind (void)
-{
- frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
-}
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