Re: [Libguestfs] [PATCH nbdkit] python: Turn python exceptions into nbdkit errors properly.

On 04/05/2018 07:47 AM, Richard W.M. Jones wrote: > --- > configure.ac | 8 +++++++ > plugins/python/python.c | 51 +++++++++++++++++++++++++++++++++++++++--- > tests/Makefile.am | 1 + > tests/python-exception.py | 45 +++++++++++++++++++++++++++++++++++++ > tests/test-python-exception.sh | 42 ++++++++++++++++++++++++++++++++++ > 5 files changed, 144 insertions(+), 3 deletions(-) > > +/* Convert bytes/str/unicode into a string. Caller must free. */ > +static char * > +python_to_string (PyObject *str) > +{ > + char *r; > + > + if (str) { > +#ifdef HAVE_PYUNICODE_ASUTF8 > + if (PyUnicode_Check (str)) { > + r = PyUnicode_AsUTF8 (str); > + r = strdup (r); > + return r; Any simpler to just write: return strdup (PyUnicode_AsUTF8 (str)); instead of using the temporary variable r?

> static int > check_python_failure (const char *callback) > { > if (PyErr_Occurred ()) { > - nbdkit_error ("%s: callback failed: %s", script, callback); > - /* How to turn this into a string? XXX */ > - PyErr_Print (); > + PyObject *type, *error, *traceback, *error_str; > + char *error_cstr; > + > + /* Convert the Python exception to a string. > + * https://stackoverflow.com/a/1418703 > + * But forget about the traceback, it's very hard to print. > + * https://stackoverflow.com/q/1796510 > + */ > + PyErr_Fetch (&type, &error, &traceback); > + PyErr_NormalizeException (&type, &error, &traceback); > + error_str = PyObject_Str (error); > + error_cstr = python_to_string (error_str); > + nbdkit_error ("%s: %s: error: %s", > + script, callback, error_cstr ? : "<unknown>"); Okay, not the first use of that gcc extension.