This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [RFA][python] Add gdb.Value.string method.
- From: Thiago Jung Bauermann <bauerman at br dot ibm dot com>
- To: gdb-patches ml <gdb-patches at sourceware dot org>
- Cc: Eli Zaretskii <eliz at gnu dot org>
- Date: Tue, 03 Feb 2009 11:56:57 -0200
- Subject: Re: [RFA][python] Add gdb.Value.string method.
- References: <1230949647.8380.145.camel@localhost.localdomain>
Hi Eli,
I'm not sure if you're aware, this patch didn't get a documentation
review/approval yet.
Thanks for your speedy review on the other Python patches, by the way.
--
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center
El sÃb, 03-01-2009 a las 00:27 -0200, Thiago Jung Bauermann escribiÃ:
> Hi,
>
> This patch adds a method to the Value python class which returns the
> value as a Python Unicode string. It depends on the patch I just posted
> in the "Add la_getstr member to language_defn", and assumes that the
> "Fixes and improvements to gdb.Value" patch has been applied. Ok?
> --
> []'s
> Thiago Jung Bauermann
> IBM Linux Technology Center
>
>
> gdb/
> 2009-01-03 Thiago Jung Bauermann <bauerman@br.ibm.com>
> Tom Tromey <tromey@redhat.com>
>
> * python/python-utils.c (target_string_to_unicode): New function.
> * python/python-internal.h (target_string_to_unicode): New prototype.
> * python/python-value.c (valpy_string): New function.
> (value_object_methods): Add `string' entry.
>
> gdb/doc/
> 2009-01-03 Tom Tromey <tromey@redhat.com>
>
> * gdb.texinfo (Values From Inferior): Document Value.string.
>
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 030d4b3..3b1cd91 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -18202,6 +18202,31 @@ The result @code{bar} will be a @code{gdb.Value} object holding the
> value pointed to by @code{foo}.
> @end defmethod
>
> +@defmethod Value string @r{[}encoding @r{[}errors@r{]}@r{]}
> +If this @code{gdb.Value} represents a string, then this method
> +converts the contents to a Python string. Otherwise, this method will
> +throw an exception.
> +
> +Strings are recognized in a language-specific way; whether a given
> +@code{gdb.Value} represents a string is determined by the current
> +language.
> +
> +For C-like languages, a value is a string if it is a pointer to or an
> +array of characters or ints. The string is assumed to be terminated
> +by a zero of the appropriate width.
> +
> +If the optional @var{encoding} argument is given, it must be a string
> +naming the encoding of the string in the @code{gdb.Value}. The Python
> +codec machinery will be used to convert the string. If @var{encoding}
> +is not given, or if @var{encoding} is the empty string, then either
> +the @code{target-charset} (@pxref{Character Sets}) will be used, or a
> +language-specific encoding will be used, if the current language is
> +able to supply one.
> +
> +The optional @var{errors} argument is the same as the corresponding
> +argument to Python's @code{string.decode} method.
> +@end defmethod
> +
> @node Interpreters
> @chapter Command Interpreters
> @cindex command interpreters
> diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
> index bcd37e4..9c2e8c6 100644
> --- a/gdb/python/python-internal.h
> +++ b/gdb/python/python-internal.h
> @@ -88,6 +88,7 @@ PyObject *python_string_to_unicode (PyObject *obj);
> char *unicode_to_target_string (PyObject *unicode_str);
> char *python_string_to_target_string (PyObject *obj);
> char *python_string_to_host_string (PyObject *obj);
> +PyObject *target_string_to_unicode (const gdb_byte *str, int length);
> int gdbpy_is_string (PyObject *obj);
>
> #endif /* GDB_PYTHON_INTERNAL_H */
> diff --git a/gdb/python/python-utils.c b/gdb/python/python-utils.c
> index c27a930..1e6d952 100644
> --- a/gdb/python/python-utils.c
> +++ b/gdb/python/python-utils.c
> @@ -160,6 +160,19 @@ python_string_to_host_string (PyObject *obj)
> return unicode_to_encoded_string (str, host_charset ());
> }
>
> +/* Converts a target string of LENGTH bytes in the target's charset to a
> + Python Unicode string. If LENGTH is -1, convert until a null byte is found.
> +
> + Returns NULL on error, with a python exception set. */
> +PyObject *
> +target_string_to_unicode (const gdb_byte *str, int length)
> +{
> + if (length == -1)
> + length = strlen (str);
> +
> + return PyUnicode_Decode (str, length, target_charset (), NULL);
> +}
> +
> /* Return true if OBJ is a Python string or unicode object, false
> otherwise. */
>
> diff --git a/gdb/python/python-value.c b/gdb/python/python-value.c
> index 4d1f864..c6775b2 100644
> --- a/gdb/python/python-value.c
> +++ b/gdb/python/python-value.c
> @@ -148,6 +148,47 @@ valpy_address (PyObject *self, PyObject *args)
> return value_to_value_object (res_val);
> }
>
> +/* Return Unicode string with value contents (assumed to be encoded in the
> + target's charset). */
> +static PyObject *
> +valpy_string (PyObject *self, PyObject *args)
> +{
> + int length, ret = 0;
> + gdb_byte *buffer;
> + struct value *value = ((value_object *) self)->value;
> + volatile struct gdb_exception except;
> + PyObject *unicode;
> + const char *encoding = NULL;
> + const char *errors = NULL;
> + const char *user_encoding = NULL;
> + const char *la_encoding = NULL;
> +
> + if (!PyArg_ParseTuple (args, "|ss", &user_encoding, &errors))
> + return NULL;
> +
> + TRY_CATCH (except, RETURN_MASK_ALL)
> + {
> + ret = LA_GET_STRING (value, &buffer, &length, &la_encoding);
> + }
> + GDB_PY_HANDLE_EXCEPTION (except);
> +
> + if (ret != 0)
> + {
> + /* We may have read a partial string before the error happened, but
> + we will ignore it and throw an exception anyway. */
> + PyErr_SetString (PyExc_RuntimeError, safe_strerror (ret));
> + xfree (buffer);
> +
> + return NULL;
> + }
> +
> + encoding = (user_encoding && *user_encoding) ? user_encoding : la_encoding;
> + unicode = PyUnicode_Decode (buffer, length, encoding, errors);
> + xfree (buffer);
> +
> + return unicode;
> +}
> +
> static Py_ssize_t
> valpy_length (PyObject *self)
> {
> @@ -773,6 +814,8 @@ gdbpy_initialize_values (void)
> static PyMethodDef value_object_methods[] = {
> { "address", valpy_address, METH_NOARGS, "Return the address of the value." },
> { "dereference", valpy_dereference, METH_NOARGS, "Dereferences the value." },
> + { "string", valpy_string, METH_VARARGS,
> + "Return Unicode string representation of the value." },
> {NULL} /* Sentinel */
> };
>
>
>