RFC: Python gdb.Type method returning optimized out gdb.Value
Commit Message
Provide the ability for a a Python frame decorator to indicate that
a value is not available.
doc/ChangeLog:
2015-04-03 Sasha Smundak <asmundak@google.com>
* python.texi:New method documented.
gdb/ChangeLog:
2015-04-03 Sasha Smundak <asmundak@google.com>
* python/py-type.c (typy_create_optimized_out): New function.
testsuite/ChangeLog:
2015-04-03 Sasha Smundak <asmundak@google.com>
* gdb.python/py-type.exp: New test.
test_fields "c"
Comments
Alexander Smundak writes:
> Provide the ability for a a Python frame decorator to indicate that
> a value is not available.
>
> doc/ChangeLog:
>
> 2015-04-03 Sasha Smundak <asmundak@google.com>
>
> * python.texi:New method documented.
>
> gdb/ChangeLog:
>
> 2015-04-03 Sasha Smundak <asmundak@google.com>
>
> * python/py-type.c (typy_create_optimized_out): New function.
>
> testsuite/ChangeLog:
>
> 2015-04-03 Sasha Smundak <asmundak@google.com>
>
> * gdb.python/py-type.exp: New test.
Hi.
A few of nits.
The terms "unavailable" and "optimized out" have different meanings
in gdb. See their definitions at the top of value.h.
Also see the comments for struct value.{unavailable,optimized_out}
in value.c. I don't know if python frame decorators would want to specify
a value as being unavailable (in gdb parlance), but don't use "unavailable"
in the documentation of "optimized out".
The "create_" in "create_optimized_out" is incongruous with the
rest of gdb.Type methods. E.g., we have "array" not "create_array",
"vector" not "create_vector", "const" not "create_const", and so on.
Does "optimized_out" read well to you?
A NEWS entry is needed.
>
> diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
> index 098d718..7c2d0bc 100644
> --- a/gdb/doc/python.texi
> +++ b/gdb/doc/python.texi
> @@ -1060,6 +1060,11 @@ If @var{block} is given, then @var{name} is
> looked up in that scope.
> Otherwise, it is searched for globally.
> @end defun
>
> +@defun Type.create_optimized_out ()
> +Return @code{gdb.Value} instance of this type whose value is optimized
> +out. Allows a frame decorator to indicate that an argument or local
> +variable value is unavailable.
> +@end defun
>
> Each type has a code, which indicates what category this type falls
> into. The available type categories are represented by constants
> diff --git a/gdb/python/py-type.c b/gdb/python/py-type.c
> index 39376a1..186cc19 100644
> --- a/gdb/python/py-type.c
> +++ b/gdb/python/py-type.c
> @@ -1181,6 +1181,14 @@ typy_nonzero (PyObject *self)
> return 1;
> }
>
> +/* Return optimized out value of this type. */
blank line
> +static PyObject *
> +typy_create_optimized_out (PyObject *self, PyObject *args)
> +{
> + struct type *type = ((type_object *) self)->type;
> + return value_to_value_object (allocate_optimized_out_value (type));
> +}
> +
> /* Return a gdb.Field object for the field named by the argument. */
>
> static PyObject *
> @@ -1493,6 +1501,8 @@ They are first class values." },
> { "const", typy_const, METH_NOARGS,
> "const () -> Type\n\
> Return a const variant of this type." },
> + { "create_optimized_out", typy_create_optimized_out, METH_NOARGS,
> +"create_optimized_out() -> Value\nReturn optimized out value of this type." },
> { "fields", typy_fields, METH_NOARGS,
> "fields () -> list\n\
> Return a list holding all the fields of this type.\n\
> diff --git a/gdb/testsuite/gdb.python/py-type.exp
> b/gdb/testsuite/gdb.python/py-type.exp
> index c4c8d9f..c73f831 100644
> --- a/gdb/testsuite/gdb.python/py-type.exp
> +++ b/gdb/testsuite/gdb.python/py-type.exp
> @@ -253,6 +253,9 @@ gdb_test "python print
> gdb.lookup_type('char').array(1, 0)" \
> gdb_test "python print gdb.lookup_type('char').array(1, -1)" \
> "Array length must not be negative.*"
>
> +gdb_test "python print gdb.lookup_type('int').create_optimized_out()" \
> + "<optimized out>"
> +
> with_test_prefix "lang_c" {
> runto_bp "break to inspect struct and array."
> test_fields "c"
@@ -1060,6 +1060,11 @@ If @var{block} is given, then @var{name} is
looked up in that scope.
Otherwise, it is searched for globally.
@end defun
+@defun Type.create_optimized_out ()
+Return @code{gdb.Value} instance of this type whose value is optimized
+out. Allows a frame decorator to indicate that an argument or local
+variable value is unavailable.
+@end defun
Each type has a code, which indicates what category this type falls
into. The available type categories are represented by constants
@@ -1181,6 +1181,14 @@ typy_nonzero (PyObject *self)
return 1;
}
+/* Return optimized out value of this type. */
+static PyObject *
+typy_create_optimized_out (PyObject *self, PyObject *args)
+{
+ struct type *type = ((type_object *) self)->type;
+ return value_to_value_object (allocate_optimized_out_value (type));
+}
+
/* Return a gdb.Field object for the field named by the argument. */
static PyObject *
@@ -1493,6 +1501,8 @@ They are first class values." },
{ "const", typy_const, METH_NOARGS,
"const () -> Type\n\
Return a const variant of this type." },
+ { "create_optimized_out", typy_create_optimized_out, METH_NOARGS,
+"create_optimized_out() -> Value\nReturn optimized out value of this type." },
{ "fields", typy_fields, METH_NOARGS,
"fields () -> list\n\
Return a list holding all the fields of this type.\n\
b/gdb/testsuite/gdb.python/py-type.exp
@@ -253,6 +253,9 @@ gdb_test "python print
gdb.lookup_type('char').array(1, 0)" \
gdb_test "python print gdb.lookup_type('char').array(1, -1)" \
"Array length must not be negative.*"
+gdb_test "python print gdb.lookup_type('int').create_optimized_out()" \
+ "<optimized out>"
+
with_test_prefix "lang_c" {
runto_bp "break to inspect struct and array."