Re: [PATCH v3 2/3] Guile: add {r,}value-reference-value

[Andrew Burgess <andrew.burgess@embecosm.com>]

* George Barrett via Gdb-patches <gdb-patches@sourceware.org> [2021-04-29 02:27:37 +1000]:

> The Guile API doesn't currently have an equivalent to the Python API's
> Value.reference_value() or Value.rvalue_reference_value(). This commit
> adds a procedure with equivalent semantics to the Guile API.

Thank you for doing this work.  I'm sorry to be a real pain, but could
you rename the second new function to value-rvalue-reference-value
please, I think this would be inline with the existing naming
convention; the first 'value-' indicates that the function applies to
something of value type, and the rest of the name
'rvalue-reference-value' indicates what you're going to get.

If you just make the rename as suggested, then this patch is approved.

Thanks,
Andrew

> 
> gdb/ChangeLog:
> 
> 2021-04-29  George Barrett  <bob@bob131.so>
> 
> 	* guile/scm-value.c (gdbscm_reference_value): Add helper
> 	function for reference value creation.
> 	(gdbscm_value_reference_value): Add implementation of
> 	value-reference-value procedure.
> 	(gdbscm_rvalue_reference_value): Add implementation of
> 	rvalue-reference-value procedure.
> 	(value_functions): Add value-reference-value procedure.
> 	Add rvalue-reference-value procedure.
> 	* NEWS (Guile API): Note the addition of new procedures.
> 
> gdb/doc/ChangeLog:
> 
> 2021-04-29  George Barrett  <bob@bob131.so>
> 
> 	* guile.texi (Values From Inferior In Guile): Add
> 	documentation for value-reference-value.
> 	Add documentation for rvalue-reference-value.
> 
> gdb/testsuite/ChangeLog:
> 
> 2021-04-29  George Barrett  <bob@bob131.so>
> 
> 	* gdb.guile/scm-value.exp (test_value_in_inferior): Add test
> 	for value-reference-value.
> 	Add test for rvalue-reference-value.
> ---
>  gdb/NEWS                              |  3 ++
>  gdb/doc/guile.texi                    | 10 +++++++
>  gdb/guile/scm-value.c                 | 42 +++++++++++++++++++++++++++
>  gdb/testsuite/gdb.guile/scm-value.exp | 10 +++++++
>  4 files changed, 65 insertions(+)
> 
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 9c76df8b6d5..0c51f5fceca 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -192,6 +192,9 @@ QMemTags
>       value-referenced-value procedure now handles rvalue reference
>       values.
>  
> +  ** New procedures for obtaining reference values:
> +     value-reference-value and rvalue-reference-value.
> +
>  *** Changes in GDB 10
>  
>  * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
> diff --git a/gdb/doc/guile.texi b/gdb/doc/guile.texi
> index c7904574002..18782bb7589 100644
> --- a/gdb/doc/guile.texi
> +++ b/gdb/doc/guile.texi
> @@ -801,6 +801,16 @@ The @code{<gdb:value>} object @code{scm-val} is identical to that
>  corresponding to @code{val}.
>  @end deffn
>  
> +@deffn {Scheme Procedure} value-reference-value value
> +Return a new @code{<gdb:value>} object which is a reference to the value
> +encapsulated by @code{<gdb:value>} object @var{value}.
> +@end deffn
> +
> +@deffn {Scheme Procedure} rvalue-reference-value value
> +Return a new @code{<gdb:value>} object which is an rvalue reference to
> +the value encapsulated by @code{<gdb:value>} object @var{value}.
> +@end deffn
> +
>  @deffn {Scheme Procedure} value-field value field-name
>  Return field @var{field-name} from @code{<gdb:value>} object @var{value}.
>  @end deffn
> diff --git a/gdb/guile/scm-value.c b/gdb/guile/scm-value.c
> index f50e8b5b46c..2ab193f044a 100644
> --- a/gdb/guile/scm-value.c
> +++ b/gdb/guile/scm-value.c
> @@ -488,6 +488,38 @@ gdbscm_value_referenced_value (SCM self)
>      });
>  }
>  
> +static SCM
> +gdbscm_reference_value (SCM self, enum type_code refcode)
> +{
> +  value_smob *v_smob
> +    = vlscm_get_value_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
> +  struct value *value = v_smob->value;
> +
> +  return gdbscm_wrap ([=]
> +    {
> +      scoped_value_mark free_values;
> +
> +      struct value *res_val = value_ref (value, refcode);
> +      return vlscm_scm_from_value (res_val);
> +    });
> +}
> +
> +/* (value-reference-value <gdb:value>) -> <gdb:value> */
> +
> +static SCM
> +gdbscm_value_reference_value (SCM self)
> +{
> +  return gdbscm_reference_value (self, TYPE_CODE_REF);
> +}
> +
> +/* (rvalue-reference-value <gdb:value>) -> <gdb:value> */
> +
> +static SCM
> +gdbscm_rvalue_reference_value (SCM self)
> +{
> +  return gdbscm_reference_value (self, TYPE_CODE_RVALUE_REF);
> +}
> +
>  /* (value-type <gdb:value>) -> <gdb:type> */
>  
>  static SCM
> @@ -1352,6 +1384,16 @@ For example, for a value which is a reference to an 'int' pointer ('int *'),\n\
>  value-dereference will result in a value of type 'int' while\n\
>  value-referenced-value will result in a value of type 'int *'." },
>  
> +  { "value-reference-value", 1, 0, 0,
> +    as_a_scm_t_subr (gdbscm_value_reference_value),
> +    "\
> +Return a <gdb:value> object which is a reference to the given value." },
> +
> +  { "rvalue-reference-value", 1, 0, 0,
> +    as_a_scm_t_subr (gdbscm_rvalue_reference_value),
> +    "\
> +Return a <gdb:value> object which is an rvalue reference to the given value." },
> +
>    { "value-field", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_field),
>      "\
>  Return the specified field of the value.\n\
> diff --git a/gdb/testsuite/gdb.guile/scm-value.exp b/gdb/testsuite/gdb.guile/scm-value.exp
> index 191af1d71a6..883c4bea72e 100644
> --- a/gdb/testsuite/gdb.guile/scm-value.exp
> +++ b/gdb/testsuite/gdb.guile/scm-value.exp
> @@ -173,6 +173,16 @@ proc test_value_in_inferior {} {
>  	"get string beyond null"
>      gdb_test "gu (print nullst)" \
>  	"= divide\\\\000et"
> +
> +    gdb_scm_test_silent_cmd "gu (define argv-ref (value-reference-value argv))" \
> +	"test value-reference-value"
> +    gdb_test "gu (equal? argv (value-referenced-value argv-ref))" "#t"
> +    gdb_test "gu (eqv? (type-code (value-type argv-ref)) TYPE_CODE_REF)" "#t"
> +
> +    gdb_scm_test_silent_cmd "gu (define argv-rref (rvalue-reference-value argv))" \
> +	"test rvalue-reference-value"
> +    gdb_test "gu (equal? argv (value-referenced-value argv-rref))" "#t"
> +    gdb_test "gu (eqv? (type-code (value-type argv-rref)) TYPE_CODE_RVALUE_REF)" "#t"
>  }
>  
>  proc test_strings {} {
> -- 
> 2.30.2