gdb: Move value_from_host_double into value.c and make more use of it

The function value_from_host_double can be moved from f-lang.c into
value.c as a generally useful function, and then used more widely.

Tested on X86-64/GNU Linux with no regressions.

gdb/ChangeLog:

	* f-lang.c (value_from_host_double): Moved to...
	* value.c (value_from_host_double): ...here.
	* value.h (value_from_host_double): Declare.
	* guile/scm-math.c (vlscm_convert_typed_number): Use
	value_from_host_double.
	(vlscm_convert_number): Likewise.
	* guile/scm-value.c (gdbscm_value_to_real): Likewise.
	* python/py-value.c (convert_value_from_python): Likewise.

gdb/ChangeLog

@@ -1,3 +1,14 @@
+2019-03-07  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* f-lang.c (value_from_host_double): Moved to...
+	* value.c (value_from_host_double): ...here.
+	* value.h (value_from_host_double): Declare.
+	* guile/scm-math.c (vlscm_convert_typed_number): Use
+	value_from_host_double.
+	(vlscm_convert_number): Likewise.
+	* guile/scm-value.c (gdbscm_value_to_real): Likewise.
+	* python/py-value.c (convert_value_from_python): Likewise.
+
 2019-03-06  Tom Tromey  <tom@tromey.com>
 
 	* gcore.c (write_gcore_file): Use SCOPE_EXIT.

gdb/f-lang.c

@@ -241,20 +241,6 @@ f_collect_symbol_completion_matches (completion_tracker &tracker,
 						      text, word, ":", code);
 }
 
-/* Create and return a value object of TYPE containing the value D.  The
-   TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
-   it is converted to target format.  */
-
-static struct value *
-value_from_host_double (struct type *type, double d)
-{
-  struct value *value = allocate_value (type);
-  gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
-  target_float_from_host_double (value_contents_raw (value),
-                                 value_type (value), d);
-  return value;
-}
-
 /* Special expression evaluation cases for Fortran.  */
 struct value *
 evaluate_subexp_f (struct type *expect_type, struct expression *exp,

gdb/guile/scm-math.c

@@ -559,13 +559,7 @@ vlscm_convert_typed_number (const char *func_name, int obj_arg_pos, SCM obj,
 	}
     }
   else if (TYPE_CODE (type) == TYPE_CODE_FLT)
-    {
-      struct value *value = allocate_value (type);
-      target_float_from_host_double (value_contents_raw (value),
-				     value_type (value),
-				     scm_to_double (obj));
-      return value;
-    }
+    return value_from_host_double (type, scm_to_double (obj));
   else
     {
       *except_scmp = gdbscm_make_type_error (func_name, obj_arg_pos, obj,
@@ -645,13 +639,7 @@ vlscm_convert_number (const char *func_name, int obj_arg_pos, SCM obj,
 				   gdbscm_scm_to_ulongest (obj));
     }
   else if (scm_is_real (obj))
-    {
-      struct value *value = allocate_value (bt->builtin_double);
-      target_float_from_host_double (value_contents_raw (value),
-				     value_type (value),
-				     scm_to_double (obj));
-      return value;
-    }
+    return value_from_host_double (bt->builtin_double, scm_to_double (obj));
 
   *except_scmp = gdbscm_make_out_of_range_error (func_name, obj_arg_pos, obj,
 			_("value not a number representable on the target"));

gdb/guile/scm-value.c

@@ -903,8 +903,7 @@ gdbscm_value_to_real (SCM self)
       if (is_floating_value (value))
 	{
 	  d = target_float_to_host_double (value_contents (value), type);
-	  check = allocate_value (type);
-	  target_float_from_host_double (value_contents_raw (check), type, d);
+	  check = value_from_host_double (type, d);
 	}
       else if (TYPE_UNSIGNED (type))
 	{

gdb/python/py-value.c

@@ -1739,11 +1739,7 @@ convert_value_from_python (PyObject *obj)
 	  double d = PyFloat_AsDouble (obj);
 
 	  if (! PyErr_Occurred ())
-	    {
-	      value = allocate_value (builtin_type_pyfloat);
-	      target_float_from_host_double (value_contents_raw (value),
-					     value_type (value), d);
-	    }
+	    value = value_from_host_double (builtin_type_pyfloat, d);
 	}
       else if (gdbpy_is_string (obj))
 	{

gdb/value.c

@@ -3430,6 +3430,19 @@ value_from_pointer (struct type *type, CORE_ADDR addr)
   return val;
 }
 
+/* Create and return a value object of TYPE containing the value D.  The
+   TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
+   it is converted to target format.  */
+
+struct value *
+value_from_host_double (struct type *type, double d)
+{
+  struct value *value = allocate_value (type);
+  gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+  target_float_from_host_double (value_contents_raw (value),
+				 value_type (value), d);
+  return value;
+}
 
 /* Create a value of type TYPE whose contents come from VALADDR, if it
    is non-null, and whose memory address (in the inferior) is

gdb/value.h

@@ -669,6 +669,7 @@ extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
 extern struct value *value_from_longest (struct type *type, LONGEST num);
 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
+extern struct value *value_from_host_double (struct type *type, double d);
 extern struct value *value_from_history_ref (const char *, const char **);
 extern struct value *value_from_component (struct value *, struct type *,
 					   LONGEST);