X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decode.c;h=a6366b1e190f55cbd43285937a08fa364ae9dc2e;hp=2cae1dbbf0106768b9950fe9716ecafdab60dfe1;hb=7ea73e33f50211a1b3df6556f6fcfcbab6c36735;hpb=0895f56aa091fabc4761862f43020b53396ed9d5 diff --git a/decode.c b/decode.c index 2cae1db..a6366b1 100644 --- a/decode.c +++ b/decode.c @@ -22,6 +22,7 @@ #include #include #include +#include /* Re-define some string functions for Python >= 3.0. */ #if PY_VERSION_HEX >= 0x03000000 @@ -33,16 +34,33 @@ /* The list of protocol decoders. */ GSList *list_pds = NULL; +/* + * Here's a quick overview of Python/C API reference counting. + * + * Check the Python/C API docs for what type of reference a function returns. + * + * - If it returns a "new reference", you're responsible to Py_XDECREF() it. + * + * - If it returns a "borrowed reference", you MUST NOT Py_XDECREF() it. + * + * - If a function "steals" a reference, you no longer are responsible for + * Py_XDECREF()ing it (someone else will do it for you at some point). + */ + +static int srd_load_decoder(const char *name, struct srd_decoder **dec); + /** * Initialize libsigrokdecode. * - * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. + * @return SRD_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_init(void) +int srd_init(void) { DIR *dir; struct dirent *dp; - char *tmp; + char *decodername; + struct srd_decoder *dec; + int ret; /* Py_Initialize() returns void and usually cannot fail. */ Py_Initialize(); @@ -51,21 +69,30 @@ int sigrokdecode_init(void) /* FIXME: Check error code. */ /* FIXME: What happens if this function is called multiple times? */ PyRun_SimpleString("import sys;" - "sys.path.append('" DECODERS_DIR "');"); + "sys.path.append(r'" DECODERS_DIR "');"); if (!(dir = opendir(DECODERS_DIR))) - return SIGROKDECODE_ERR_DECODERS_DIR; + return SRD_ERR_DECODERS_DIR; while ((dp = readdir(dir)) != NULL) { if (!g_str_has_suffix(dp->d_name, ".py")) continue; - /* For now use the filename (without .py) as decoder name. */ - if ((tmp = g_strndup(dp->d_name, strlen(dp->d_name) - 3))) - list_pds = g_slist_append(list_pds, tmp); + + /* Decoder name == filename (without .py suffix). */ + decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3); + + /* TODO: Error handling. */ + dec = malloc(sizeof(struct srd_decoder)); + + /* Load the decoder. */ + ret = srd_load_decoder(decodername, &dec); + + /* Append it to the list of supported/loaded decoders. */ + list_pds = g_slist_append(list_pds, dec); } closedir(dir); - return SIGROKDECODE_OK; + return SRD_OK; } /** @@ -75,17 +102,37 @@ int sigrokdecode_init(void) * * @return List of decoders, NULL if none are supported or loaded. */ -GSList *sigrokdecode_list_decoders(void) +GSList *srd_list_decoders(void) { return list_pds; } +/** + * Get the decoder with the specified ID. + * + * @param id The ID string of the decoder to return. + * @return The decoder with the specified ID, or NULL if not found. + */ +struct srd_decoder *srd_get_decoder_by_id(const char *id) +{ + GSList *l; + struct srd_decoder *dec; + + for (l = srd_list_decoders(); l; l = l->next) { + dec = l->data; + if (!strcmp(dec->id, id)) + return dec; + } + + return NULL; +} + /** * Helper function to handle Python strings. * * TODO: @param entries. * - * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. + * @return SRD_OK upon success, a (negative) error code otherwise. * The 'outstr' argument points to a malloc()ed string upon success. */ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, @@ -93,37 +140,43 @@ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, { PyObject *py_str; char *str; + int ret; py_str = PyMapping_GetItemString(py_res, (char *)key); if (!py_str || !PyString_Check(py_str)) { - if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + goto err_h_decref_func; } + /* + * PyString_AsString()'s returned string refers to an internal buffer + * (not a copy), i.e. the data must not be modified, and the memory + * must not be free()'d. + */ if (!(str = PyString_AsString(py_str))) { - if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_str); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + goto err_h_decref_str; } - if (!(*outstr = strdup(str))) { - if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_str); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_MALLOC; + if (!(*outstr = g_strdup(str))) { + ret = SRD_ERR_MALLOC; + goto err_h_decref_str; } - Py_DECREF(py_str); + Py_XDECREF(py_str); + + return SRD_OK; + +err_h_decref_str: + Py_XDECREF(py_str); +err_h_decref_func: + Py_XDECREF(py_func); + Py_XDECREF(py_mod); + + if (PyErr_Occurred()) + PyErr_Print(); /* Returns void. */ - return SIGROKDECODE_OK; + return ret; } /** @@ -131,48 +184,40 @@ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, * * @param name TODO * - * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. + * @return SRD_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_load_decoder(const char *name, - struct sigrokdecode_decoder **dec) +static int srd_load_decoder(const char *name, + struct srd_decoder **dec) { - struct sigrokdecode_decoder *d; - PyObject *py_name, *py_mod, *py_func, *py_res /* , *py_tuple */; + struct srd_decoder *d; + PyObject *py_mod, *py_func, *py_res /* , *py_tuple */; int r; - /* Get the name of the decoder module as Python string. */ - if (!(py_name = PyString_FromString(name))) { - PyErr_Print(); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ - } - /* "Import" the Python module. */ - if (!(py_mod = PyImport_Import(py_name))) { - PyErr_Print(); - Py_DECREF(py_name); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if (!(py_mod = PyImport_ImportModule(name))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ + return SRD_ERR_PYTHON; /* TODO: More specific error? */ } - Py_DECREF(py_name); /* Get the 'register' function name as Python callable object. */ - py_func = PyObject_GetAttrString(py_mod, "register"); + py_func = PyObject_GetAttrString(py_mod, "register"); /* NEWREF */ if (!py_func || !PyCallable_Check(py_func)) { if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + PyErr_Print(); /* Returns void. */ + Py_XDECREF(py_mod); + return SRD_ERR_PYTHON; /* TODO: More specific error? */ } /* Call the 'register' function without arguments, get the result. */ - if (!(py_res = PyObject_CallFunction(py_func, NULL))) { - PyErr_Print(); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if (!(py_res = PyObject_CallFunction(py_func, NULL))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ + Py_XDECREF(py_func); + Py_XDECREF(py_mod); + return SRD_ERR_PYTHON; /* TODO: More specific error? */ } - if (!(d = malloc(sizeof(struct sigrokdecode_decoder)))) - return SIGROKDECODE_ERR_MALLOC; + if (!(d = malloc(sizeof(struct srd_decoder)))) + return SRD_ERR_MALLOC; if ((r = h_str(py_res, py_func, py_mod, "id", &(d->id))) < 0) return r; @@ -185,25 +230,29 @@ int sigrokdecode_load_decoder(const char *name, d->py_mod = py_mod; - Py_DECREF(py_res); - Py_DECREF(py_func); + Py_XDECREF(py_res); + Py_XDECREF(py_func); /* Get the 'decode' function name as Python callable object. */ - py_func = PyObject_GetAttrString(py_mod, "decode"); + py_func = PyObject_GetAttrString(py_mod, "decode"); /* NEWREF */ if (!py_func || !PyCallable_Check(py_func)) { if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + PyErr_Print(); /* Returns void. */ + Py_XDECREF(py_mod); + return SRD_ERR_PYTHON; /* TODO: More specific error? */ } d->py_func = py_func; - /* TODO: Handle inputformats, outputformats. */ + /* TODO: Handle func, inputformats, outputformats. */ + /* Note: They must at least be set to NULL, will segfault otherwise. */ + d->func = NULL; + d->inputformats = NULL; + d->outputformats = NULL; *dec = d; - return SIGROKDECODE_OK; + return SRD_OK; } /** @@ -215,100 +264,141 @@ int sigrokdecode_load_decoder(const char *name, * @param outbuf TODO * @param outbuflen TODO * - * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. + * @return SRD_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, +int srd_run_decoder(struct srd_decoder *dec, uint8_t *inbuf, uint64_t inbuflen, uint8_t **outbuf, uint64_t *outbuflen) { PyObject *py_mod, *py_func, *py_args, *py_value, *py_res; - int ret; + int r, ret; /* TODO: Use #defines for the return codes. */ /* Return an error upon unusable input. */ if (dec == NULL) - return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ + return SRD_ERR_ARGS; /* TODO: More specific error? */ if (inbuf == NULL) - return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ + return SRD_ERR_ARGS; /* TODO: More specific error? */ if (inbuflen == 0) /* No point in working on empty buffers. */ - return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ + return SRD_ERR_ARGS; /* TODO: More specific error? */ if (outbuf == NULL) - return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ + return SRD_ERR_ARGS; /* TODO: More specific error? */ if (outbuflen == NULL) - return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ + return SRD_ERR_ARGS; /* TODO: More specific error? */ /* TODO: Error handling. */ py_mod = dec->py_mod; + Py_XINCREF(py_mod); py_func = dec->py_func; - - /* TODO: Really run Py_DECREF on py_mod/py_func? */ + Py_XINCREF(py_func); /* Create a Python tuple of size 1. */ - if (!(py_args = PyTuple_New(1))) { - PyErr_Print(); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if (!(py_args = PyTuple_New(1))) { /* NEWREF */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + goto err_run_decref_func; } /* Get the input buffer as Python "string" (byte array). */ /* TODO: int vs. uint64_t for 'inbuflen'? */ - if (!(py_value = Py_BuildValue("s#", inbuf, inbuflen))) { - PyErr_Print(); - Py_DECREF(py_args); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if (!(py_value = Py_BuildValue("s#", inbuf, inbuflen))) { /* NEWREF */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + goto err_run_decref_args; } - if (PyTuple_SetItem(py_args, 0, py_value) != 0) { - PyErr_Print(); - Py_DECREF(py_value); - Py_DECREF(py_args); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + /* + * IMPORTANT: PyTuple_SetItem() "steals" a reference to py_value! + * That means we are no longer responsible for Py_XDECREF()'ing it. + * It will automatically be free'd when the 'py_args' tuple is free'd. + */ + if (PyTuple_SetItem(py_args, 0, py_value) != 0) { /* STEAL */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + Py_XDECREF(py_value); /* TODO: Ref. stolen upon error? */ + goto err_run_decref_args; } - if (!(py_res = PyObject_CallObject(py_func, py_args))) { - PyErr_Print(); - Py_DECREF(py_value); - Py_DECREF(py_args); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if (!(py_res = PyObject_CallObject(py_func, py_args))) { /* NEWREF */ + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + goto err_run_decref_args; } - if ((ret = PyObject_AsCharBuffer(py_res, (const char **)outbuf, - (Py_ssize_t *)outbuflen))) { - PyErr_Print(); - Py_DECREF(py_res); - Py_DECREF(py_value); - Py_DECREF(py_args); - Py_DECREF(py_func); - Py_DECREF(py_mod); - return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + if ((r = PyObject_AsCharBuffer(py_res, (const char **)outbuf, + (Py_ssize_t *)outbuflen))) { + ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ + Py_XDECREF(py_res); + goto err_run_decref_args; } - Py_DECREF(py_res); - // Py_DECREF(py_value); - Py_DECREF(py_args); - Py_DECREF(py_func); - Py_DECREF(py_mod); + ret = SRD_OK; + + Py_XDECREF(py_res); + +err_run_decref_args: + Py_XDECREF(py_args); +err_run_decref_func: + Py_XDECREF(py_func); + Py_XDECREF(py_mod); + + if (PyErr_Occurred()) + PyErr_Print(); /* Returns void. */ + + return ret; +} + +/** + * TODO + */ +static int srd_unload_decoder(struct srd_decoder *dec) +{ + g_free(dec->id); + g_free(dec->name); + g_free(dec->desc); + g_free(dec->func); + + /* TODO: Free everything in inputformats and outputformats. */ + + if (dec->inputformats != NULL) + g_slist_free(dec->inputformats); + if (dec->outputformats != NULL) + g_slist_free(dec->outputformats); + + Py_XDECREF(dec->py_func); + Py_XDECREF(dec->py_mod); + + return SRD_OK; +} + +/** + * TODO + */ +static int srd_unload_all_decoders(void) +{ + GSList *l; + struct srd_decoder *dec; + + for (l = srd_list_decoders(); l; l = l->next) { + dec = l->data; + /* TODO: Error handling. */ + srd_unload_decoder(dec); + } - return SIGROKDECODE_OK; + return SRD_OK; } /** * Shutdown libsigrokdecode. * - * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. + * @return SRD_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_shutdown(void) +int srd_exit(void) { + /* Unload/free all decoders, and then the list of decoders itself. */ + /* TODO: Error handling. */ + srd_unload_all_decoders(); + g_slist_free(list_pds); + /* Py_Finalize() returns void, any finalization errors are ignored. */ Py_Finalize(); - return SIGROKDECODE_OK; + return SRD_OK; }