gdb: pass frame_info_ptr to gdbarch_value_from_register

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

@@ -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,
+			     const 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 ())

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, const frame_info_ptr &this_frame);
+extern struct value * gdbarch_value_from_register (struct gdbarch *gdbarch, struct type *type, int regnum, const 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);

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, const 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

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"),
+        ("const frame_info_ptr &", "this_frame"),
     ],
     predefault="default_value_from_register",
     invalid=False,

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,
+			    const 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

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,
+			  const 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

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,
+					   const frame_info_ptr &this_frame);
 
 extern void read_frame_register_value (struct value *value,
 				       frame_info_ptr frame);