[PATCH 2/9] gdb: pass frame_info_ptr to gdbarch_value_from_register

Simon Marchi
2023-12-21T19:17:43Z

Pass a frame_info_ptr rather than a frame_id. This avoids having to do
a frame lookup on the callee side, when we can just pass the frame down
directly.

I think this fixes a bug in rs6000-tdep.c where the id of the wrong
frame was set to `VALUE_NEXT_FRAME_ID (v)`.

Change-Id: I77039bc87ea8fc5262f16d0e1446515efa21c565
---
gdb/findvar.c | 24 ++++++++++--------------
gdb/gdbarch-gen.h | 6 +++---
gdb/gdbarch.c | 4 ++--
gdb/gdbarch_components.py | 4 ++--
gdb/rs6000-tdep.c | 16 ++++++++--------
gdb/s390-tdep.c | 10 +++++-----
gdb/value.h | 7 +++----
7 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/gdb/findvar.c b/gdb/findvar.c
index e6dedf0aadf6..25737c4e3159 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -747,23 +747,21 @@ read_var_value (struct symbol *var, const struct block *var_block,

/* Install default attributes for register values. */

-struct value *
-default_value_from_register (struct gdbarch *gdbarch, struct type *type,
- int regnum, struct frame_id frame_id)
+value *
+default_value_from_register (gdbarch *gdbarch, type *type, int regnum,
+ frame_info_ptr this_frame)
{
int len = type->length ();
struct value *value = value::allocate (type);
- frame_info_ptr frame;
-
value->set_lval (lval_register);
- frame = frame_find_by_id (frame_id);

- if (frame == NULL)
- frame_id = null_frame_id;
+ frame_id next_frame_id;
+ if (this_frame == nullptr)
+ next_frame_id = null_frame_id;
else
- frame_id = get_frame_id (get_next_frame_sentinel_okay (frame));
+ next_frame_id = get_frame_id (get_next_frame_sentinel_okay (this_frame));

- VALUE_NEXT_FRAME_ID (value) = frame_id;
+ VALUE_NEXT_FRAME_ID (value) = next_frame_id;
VALUE_REGNUM (value) = regnum;

/* Any structure stored in more than one register will always be
@@ -865,8 +863,7 @@ value_from_register (struct type *type, int regnum, frame_info_ptr frame)
else
{
/* Construct the value. */
- v = gdbarch_value_from_register (gdbarch, type,
- regnum, get_frame_id (frame));
+ v = gdbarch_value_from_register (gdbarch, type, regnum, frame);

/* Get the data. */
read_frame_register_value (v, frame);
@@ -883,7 +880,6 @@ address_from_register (int regnum, frame_info_ptr frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
struct type *type = builtin_type (gdbarch)->builtin_data_ptr;
- struct value *value;
CORE_ADDR result;
int regnum_max_excl = gdbarch_num_cooked_regs (gdbarch);

@@ -919,7 +915,7 @@ address_from_register (int regnum, frame_info_ptr frame)
return unpack_long (type, buf);
}

- value = gdbarch_value_from_register (gdbarch, type, regnum, null_frame_id);
+ value *value = gdbarch_value_from_register (gdbarch, type, regnum, nullptr);
read_frame_register_value (value, frame);

if (value->optimized_out ())
diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h
index 80d40136c379..a7761616e032 100644
--- a/gdb/gdbarch-gen.h
+++ b/gdb/gdbarch-gen.h
@@ -422,12 +422,12 @@ extern void gdbarch_value_to_register (struct gdbarch *gdbarch, frame_info_ptr f
extern void set_gdbarch_value_to_register (struct gdbarch *gdbarch, gdbarch_value_to_register_ftype *value_to_register);

/* Construct a value representing the contents of register REGNUM in
- frame FRAME_ID, interpreted as type TYPE. The routine needs to
+ frame THIS_FRAME, interpreted as type TYPE. The routine needs to
allocate and return a struct value with all value attributes
(but not the value contents) filled in. */

-typedef struct value * (gdbarch_value_from_register_ftype) (struct gdbarch *gdbarch, struct type *type, int regnum, struct frame_id frame_id);
-extern struct value * gdbarch_value_from_register (struct gdbarch *gdbarch, struct type *type, int regnum, struct frame_id frame_id);
+typedef struct value * (gdbarch_value_from_register_ftype) (struct gdbarch *gdbarch, struct type *type, int regnum, frame_info_ptr this_frame);
+extern struct value * gdbarch_value_from_register (struct gdbarch *gdbarch, struct type *type, int regnum, frame_info_ptr this_frame);
extern void set_gdbarch_value_from_register (struct gdbarch *gdbarch, gdbarch_value_from_register_ftype *value_from_register);

typedef CORE_ADDR (gdbarch_pointer_to_address_ftype) (struct gdbarch *gdbarch, struct type *type, const gdb_byte *buf);
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index d584305fefb2..6d83e17160e6 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -2557,13 +2557,13 @@ set_gdbarch_value_to_register (struct gdbarch *gdbarch,
}

struct value *
-gdbarch_value_from_register (struct gdbarch *gdbarch, struct type *type, int regnum, struct frame_id frame_id)
+gdbarch_value_from_register (struct gdbarch *gdbarch, struct type *type, int regnum, frame_info_ptr this_frame)
{
gdb_assert (gdbarch != NULL);
gdb_assert (gdbarch->value_from_register != NULL);
if (gdbarch_debug >= 2)
gdb_printf (gdb_stdlog, "gdbarch_value_from_register called\n");
- return gdbarch->value_from_register (gdbarch, type, regnum, frame_id);
+ return gdbarch->value_from_register (gdbarch, type, regnum, this_frame);
}

void
diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
index 4352f7066512..432e4b4ea267 100644
--- a/gdb/gdbarch_components.py
+++ b/gdb/gdbarch_components.py
@@ -814,7 +814,7 @@ Function(
Method(
comment="""
Construct a value representing the contents of register REGNUM in
-frame FRAME_ID, interpreted as type TYPE. The routine needs to
+frame THIS_FRAME, interpreted as type TYPE. The routine needs to
allocate and return a struct value with all value attributes
(but not the value contents) filled in.
""",
@@ -823,7 +823,7 @@ allocate and return a struct value with all value attributes
params=[
("struct type *", "type"),
("int", "regnum"),
- ("struct frame_id", "frame_id"),
+ ("frame_info_ptr", "this_frame"),
],
predefault="default_value_from_register",
invalid=False,
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index a7e0bf5305b5..a0f3d94f3a11 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -2747,9 +2747,9 @@ rs6000_value_to_register (frame_info_ptr frame,
put_frame_register (get_next_frame_sentinel_okay (frame), regnum, to_view);
}

-static struct value *
-rs6000_value_from_register (struct gdbarch *gdbarch, struct type *type,
- int regnum, struct frame_id frame_id)
+static value *
+rs6000_value_from_register (gdbarch *gdbarch, type *type, int regnum,
+ frame_info_ptr this_frame)
{
int len = type->length ();
struct value *value = value::allocate (type);
@@ -2759,14 +2759,14 @@ rs6000_value_from_register (struct gdbarch *gdbarch, struct type *type,
regnum = ieee_128_float_regnum_adjust (gdbarch, type, regnum);

value->set_lval (lval_register);
- frame_info_ptr frame = frame_find_by_id (frame_id);

- if (frame == NULL)
- frame_id = null_frame_id;
+ frame_id next_frame_id;
+ if (this_frame == nullptr)
+ next_frame_id = null_frame_id;
else
- frame_id = get_frame_id (get_next_frame_sentinel_okay (frame));
+ next_frame_id = get_frame_id (get_next_frame_sentinel_okay (this_frame));

- VALUE_NEXT_FRAME_ID (value) = frame_id;
+ VALUE_NEXT_FRAME_ID (value) = next_frame_id;
VALUE_REGNUM (value) = regnum;

/* Any structure stored in more than one register will always be
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c
index fcba7a1a5608..ebbcbc153fe1 100644
--- a/gdb/s390-tdep.c
+++ b/gdb/s390-tdep.c
@@ -1236,13 +1236,13 @@ regnum_is_vxr_full (s390_gdbarch_tdep *tdep, int regnum)
registers, even though we are otherwise a big-endian platform. The
same applies to a 'float' value within a vector. */

-static struct value *
-s390_value_from_register (struct gdbarch *gdbarch, struct type *type,
- int regnum, struct frame_id frame_id)
+static value *
+s390_value_from_register (gdbarch *gdbarch, type *type, int regnum,
+ frame_info_ptr this_frame)
{
s390_gdbarch_tdep *tdep = gdbarch_tdep<s390_gdbarch_tdep> (gdbarch);
- struct value *value = default_value_from_register (gdbarch, type,
- regnum, frame_id);
+ value *value
+ = default_value_from_register (gdbarch, type, regnum, this_frame);
check_typedef (type);

if ((regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM
diff --git a/gdb/value.h b/gdb/value.h
index d7bda1e8d2c9..d4244dadb91a 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -1110,10 +1110,9 @@ extern struct value *value_from_contents_and_address
frame_info_ptr frame = nullptr);
extern struct value *value_from_contents (struct type *, const gdb_byte *);

-extern struct value *default_value_from_register (struct gdbarch *gdbarch,
- struct type *type,
- int regnum,
- struct frame_id frame_id);
+extern value *default_value_from_register (gdbarch *gdbarch, type *type,
+ int regnum,
+ frame_info_ptr this_frame);

extern void read_frame_register_value (struct value *value,
frame_info_ptr frame);
--
2.43.0