X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decode.c;h=db29494523eb867af0d6334376ab94862f67841a;hp=e6399db72ce346bf6d2dfc4e378a11ac0a2bcb4e;hb=6b08da24ec79989565e5417cf111a243073cd2fd;hpb=5c55017c401002c18b1d43dad61200df17ab3321 diff --git a/decode.c b/decode.c index e6399db..db29494 100644 --- a/decode.c +++ b/decode.c @@ -21,27 +21,77 @@ #include /* First, so we avoid a _POSIX_C_SOURCE warning. */ #include #include +#include +#include + +/* Re-define some string functions for Python >= 3.0. */ +#if PY_VERSION_HEX >= 0x03000000 +#define PyString_AsString PyBytes_AsString +#define PyString_FromString PyBytes_FromString +#define PyString_Check PyBytes_Check +#endif + +/* 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_DECREF() it. + * + * - If it returns a "borrowed reference", you MUST NOT Py_DECREF() it. + * + * - If a function "steals" a reference, you no longer are responsible for + * Py_DECREF()ing it (someone else will do it for you at some point). + */ /** * Initialize libsigrokdecode. * - * @return 0 upon success, non-zero otherwise. + * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_init(void) { + DIR *dir; + struct dirent *dp; + char *tmp; + /* Py_Initialize() returns void and usually cannot fail. */ Py_Initialize(); - /* Add some more search directories for convenience. */ + /* Add search directory for the protocol decoders. */ /* FIXME: Check error code. */ - PyRun_SimpleString( - "import sys;" - "sys.path.append('libsigrokdecode/scripts');" - "sys.path.append('../libsigrokdecode/scripts');" - "sys.path.append('/usr/local/share/sigrok');" - ); - - return 0; + /* FIXME: What happens if this function is called multiple times? */ + PyRun_SimpleString("import sys;" + "sys.path.append(r'" DECODERS_DIR "');"); + + if (!(dir = opendir(DECODERS_DIR))) + return SIGROKDECODE_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); + } + closedir(dir); + + return SIGROKDECODE_OK; +} + +/** + * Returns the list of supported/loaded protocol decoders. + * + * This is a GSList containing the names of the decoders as strings. + * + * @return List of decoders, NULL if none are supported or loaded. + */ +GSList *sigrokdecode_list_decoders(void) +{ + return list_pds; } /** @@ -49,8 +99,8 @@ int sigrokdecode_init(void) * * TODO: @param entries. * - * @return 0 upon success, non-zero otherwise. The 'outstr' argument will - * point to a malloc()ed string upon success. + * @return SIGROKDECODE_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, const char *key, char **outstr) @@ -61,15 +111,20 @@ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, py_str = PyMapping_GetItemString(py_res, (char *)key); if (!py_str || !PyString_Check(py_str)) { if (PyErr_Occurred()) - PyErr_Print(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_func); Py_DECREF(py_mod); return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } + /* + * 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(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_str); Py_DECREF(py_func); Py_DECREF(py_mod); @@ -78,7 +133,7 @@ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, if (!(*outstr = strdup(str))) { if (PyErr_Occurred()) - PyErr_Print(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_str); Py_DECREF(py_func); Py_DECREF(py_mod); @@ -87,14 +142,15 @@ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, Py_DECREF(py_str); - return 0; + return SIGROKDECODE_OK; } /** * TODO * * @param name TODO - * @return 0 upon success, non-zero otherwise. + * + * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_load_decoder(const char *name, struct sigrokdecode_decoder **dec) @@ -104,31 +160,31 @@ int sigrokdecode_load_decoder(const char *name, int r; /* Get the name of the decoder module as Python string. */ - if (!(py_name = PyString_FromString(name))) { - PyErr_Print(); + if (!(py_name = PyString_FromString(name))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } /* "Import" the Python module. */ - if (!(py_mod = PyImport_Import(py_name))) { - PyErr_Print(); + if (!(py_mod = PyImport_Import(py_name))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ Py_DECREF(py_name); return SIGROKDECODE_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(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_mod); return SIGROKDECODE_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(); + if (!(py_res = PyObject_CallFunction(py_func, NULL))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ Py_DECREF(py_func); Py_DECREF(py_mod); return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ @@ -152,10 +208,10 @@ int sigrokdecode_load_decoder(const char *name, Py_DECREF(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(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_mod); return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } @@ -166,7 +222,7 @@ int sigrokdecode_load_decoder(const char *name, *dec = d; - return 0; + return SIGROKDECODE_OK; } /** @@ -177,7 +233,8 @@ int sigrokdecode_load_decoder(const char *name, * @param inbuflen TODO * @param outbuf TODO * @param outbuflen TODO - * @return 0 upon success, non-zero otherwise. + * + * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, uint8_t *inbuf, uint64_t inbuflen, @@ -207,8 +264,8 @@ int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, /* TODO: Really run Py_DECREF on py_mod/py_func? */ /* Create a Python tuple of size 1. */ - if (!(py_args = PyTuple_New(1))) { - PyErr_Print(); + if (!(py_args = PyTuple_New(1))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ Py_DECREF(py_func); Py_DECREF(py_mod); return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ @@ -216,26 +273,30 @@ int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, /* 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(); + if (!(py_value = Py_BuildValue("s#", inbuf, inbuflen))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ Py_DECREF(py_args); Py_DECREF(py_func); Py_DECREF(py_mod); return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } - if (PyTuple_SetItem(py_args, 0, py_value) != 0) { - PyErr_Print(); - Py_DECREF(py_value); + /* + * IMPORTANT: PyTuple_SetItem() "steals" a reference to py_value! + * That means we are no longer responsible for Py_DECREF()'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 */ + PyErr_Print(); /* Returns void. */ + Py_DECREF(py_value); /* TODO: Ref. stolen upon error? */ 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))) { - PyErr_Print(); - Py_DECREF(py_value); + if (!(py_res = PyObject_CallObject(py_func, py_args))) { /* NEWREF */ + PyErr_Print(); /* Returns void. */ Py_DECREF(py_args); Py_DECREF(py_func); Py_DECREF(py_mod); @@ -244,9 +305,8 @@ int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, if ((ret = PyObject_AsCharBuffer(py_res, (const char **)outbuf, (Py_ssize_t *)outbuflen))) { - PyErr_Print(); + PyErr_Print(); /* Returns void. */ Py_DECREF(py_res); - Py_DECREF(py_value); Py_DECREF(py_args); Py_DECREF(py_func); Py_DECREF(py_mod); @@ -254,23 +314,22 @@ int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, } Py_DECREF(py_res); - // Py_DECREF(py_value); Py_DECREF(py_args); Py_DECREF(py_func); Py_DECREF(py_mod); - return 0; + return SIGROKDECODE_OK; } /** * Shutdown libsigrokdecode. * - * @return 0 upon success, non-zero otherwise. + * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_shutdown(void) { /* Py_Finalize() returns void, any finalization errors are ignored. */ Py_Finalize(); - return 0; + return SIGROKDECODE_OK; }