[babeltrace.git] / lib / plugin / plugin-python.c

/*
 * plugin-python.c
 *
 * Babeltrace Plugin (Python)
 *
 * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <babeltrace/babeltrace-internal.h>
#include <babeltrace/compiler.h>
#include <babeltrace/ref.h>
#include <babeltrace/plugin/plugin-internal.h>
#include <babeltrace/plugin/plugin-internal.h>
#include <babeltrace/component/component-class-internal.h>
#include <stdlib.h>
#include <signal.h>
#include <Python.h>

#define PYTHON_PLUGIN_FILE_PREFIX	"bt_plugin_"
#define PYTHON_PLUGIN_FILE_PREFIX_LEN	(sizeof(PYTHON_PLUGIN_FILE_PREFIX) - 1)
#define PYTHON_PLUGIN_FILE_EXT		".py"
#define PYTHON_PLUGIN_FILE_EXT_LEN	(sizeof(PYTHON_PLUGIN_FILE_EXT) - 1)

enum python_state {
	/* init_python() not called yet */
	PYTHON_STATE_NOT_INITED,

	/* init_python() called once with success */
	PYTHON_STATE_FULLY_INITIALIZED,

	/* init_python() called once without success */
	PYTHON_STATE_CANNOT_INITIALIZE,
} python_state = PYTHON_STATE_NOT_INITED;

static PyObject *py_try_load_plugin_module_func = NULL;

static
void print_python_traceback_verbose(void)
{
	if (Py_IsInitialized() && PyErr_Occurred() && babeltrace_verbose) {
		PyErr_Print();
	}
}

static
void pyerr_clear(void)
{
	if (Py_IsInitialized()) {
		PyErr_Clear();
	}
}

static
void init_python(void)
{
	PyObject *py_bt2_py_plugin_mod = NULL;
	const char *dis_python_env;
	sighandler_t old_sigint = signal(SIGINT, SIG_DFL);

	if (python_state != PYTHON_STATE_NOT_INITED) {
		goto end;
	}

	/*
	 * User can disable Python plugin support with the
	 * BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable set to
	 * 1.
	 */
	dis_python_env = getenv("BABELTRACE_DISABLE_PYTHON_PLUGINS");
	if (dis_python_env && dis_python_env[0] == '1' &&
			dis_python_env[1] == '\0') {
		printf_verbose("Python plugin support is disabled by BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable\n");
		python_state = PYTHON_STATE_CANNOT_INITIALIZE;
		goto end;
	}

	if (!Py_IsInitialized()) {
		Py_InitializeEx(0);
		printf_verbose("Initialized Python:\n%s\n", Py_GetVersion());
	}

	py_bt2_py_plugin_mod = PyImport_ImportModule("bt2.py_plugin");
	if (!py_bt2_py_plugin_mod) {
		printf_verbose("Cannot import bt2.py_plugin Python module\n");
		python_state = PYTHON_STATE_CANNOT_INITIALIZE;
		goto end;
	}

	py_try_load_plugin_module_func =
		PyObject_GetAttrString(py_bt2_py_plugin_mod, "_try_load_plugin_module");
	if (!py_try_load_plugin_module_func) {
		printf_verbose("Cannot get _try_load_plugin_module attribute from bt2.py_plugin Python module\n");
		python_state = PYTHON_STATE_CANNOT_INITIALIZE;
		goto end;
	}

	python_state = PYTHON_STATE_FULLY_INITIALIZED;

end:
	if (old_sigint != SIG_ERR) {
		(void) signal(SIGINT, old_sigint);
	}

	print_python_traceback_verbose();
	pyerr_clear();
	Py_XDECREF(py_bt2_py_plugin_mod);
	return;
}

__attribute__((destructor)) static
void fini_python(void) {
	if (Py_IsInitialized()) {
		if (py_try_load_plugin_module_func) {
			Py_DECREF(py_try_load_plugin_module_func);
			py_try_load_plugin_module_func = NULL;
		}

		Py_Finalize();
	}

	python_state = PYTHON_STATE_NOT_INITED;
}

static
struct bt_plugin *bt_plugin_from_python_plugin_info(PyObject *plugin_info)
{
	struct bt_plugin *plugin = NULL;
	PyObject *py_name = NULL;
	PyObject *py_author = NULL;
	PyObject *py_description = NULL;
	PyObject *py_license = NULL;
	PyObject *py_version = NULL;
	PyObject *py_comp_class_addrs = NULL;
	const char *name = NULL;
	const char *author = NULL;
	const char *description = NULL;
	const char *license = NULL;
	unsigned int major = 0, minor = 0, patch = 0;
	const char *version_extra = NULL;
	int ret;

	assert(plugin_info);
	assert(python_state == PYTHON_STATE_FULLY_INITIALIZED);
	py_name = PyObject_GetAttrString(plugin_info, "name");
	if (!py_name) {
		printf_verbose("Cannot find `name` attribute in plugin info\n");
		goto error;
	}

	py_author = PyObject_GetAttrString(plugin_info, "author");
	if (!py_author) {
		printf_verbose("Cannot find `author` attribute in plugin info\n");
		goto error;
	}

	py_description = PyObject_GetAttrString(plugin_info, "description");
	if (!py_description) {
		printf_verbose("Cannot find `description` attribute in plugin info\n");
		goto error;
	}

	py_license = PyObject_GetAttrString(plugin_info, "license");
	if (!py_license) {
		printf_verbose("Cannot find `license` attribute in plugin info\n");
		goto error;
	}

	py_version = PyObject_GetAttrString(plugin_info, "version");
	if (!py_version) {
		printf_verbose("Cannot find `version` attribute in plugin info\n");
		goto error;
	}

	py_comp_class_addrs = PyObject_GetAttrString(plugin_info,
		"comp_class_addrs");
	if (!py_comp_class_addrs) {
		printf_verbose("Cannot find `comp_class_addrs` attribute in plugin info\n");
		goto error;
	}

	if (PyUnicode_Check(py_name)) {
		name = PyUnicode_AsUTF8(py_name);
		if (!name) {
			printf_verbose("Cannot decode plugin name string\n");
			goto error;
		}
	} else {
		/* Plugin name is mandatory */
		printf_verbose("Plugin name is not a string\n");
		goto error;
	}

	if (PyUnicode_Check(py_author)) {
		author = PyUnicode_AsUTF8(py_author);
		if (!author) {
			printf_verbose("Cannot decode plugin author string\n");
			goto error;
		}
	}

	if (PyUnicode_Check(py_description)) {
		description = PyUnicode_AsUTF8(py_description);
		if (!description) {
			printf_verbose("Cannot decode plugin description string\n");
			goto error;
		}
	}

	if (PyUnicode_Check(py_license)) {
		license = PyUnicode_AsUTF8(py_license);
		if (!license) {
			printf_verbose("Cannot decode plugin license string\n");
			goto error;
		}
	}

	if (PyTuple_Check(py_version)) {
		if (PyTuple_Size(py_version) >= 3) {
			PyObject *py_major = PyTuple_GetItem(py_version, 0);
			PyObject *py_minor = PyTuple_GetItem(py_version, 1);
			PyObject *py_patch = PyTuple_GetItem(py_version, 2);

			assert(py_major);
			assert(py_minor);
			assert(py_patch);

			if (PyLong_Check(py_major)) {
				major = PyLong_AsUnsignedLong(py_major);
			}

			if (PyLong_Check(py_minor)) {
				minor = PyLong_AsUnsignedLong(py_minor);
			}

			if (PyLong_Check(py_patch)) {
				patch = PyLong_AsUnsignedLong(py_patch);
			}

			if (PyErr_Occurred()) {
				/* Overflow error, most probably */
				printf_verbose("Invalid plugin version format\n");
				goto error;
			}
		}

		if (PyTuple_Size(py_version) >= 4) {
			PyObject *py_extra = PyTuple_GetItem(py_version, 3);

			assert(py_extra);

			if (PyUnicode_Check(py_extra)) {
				version_extra = PyUnicode_AsUTF8(py_extra);
				if (!version_extra) {
					printf_verbose("Cannot decode plugin version's extra string\n");
					goto error;
				}
			}
		}
	}

	plugin = bt_plugin_create_empty(BT_PLUGIN_TYPE_PYTHON);
	if (!plugin) {
		goto error;
	}

	bt_plugin_set_name(plugin, name);

	if (description) {
		bt_plugin_set_description(plugin, description);
	}

	if (author) {
		bt_plugin_set_author(plugin, author);
	}

	if (license) {
		bt_plugin_set_license(plugin, license);
	}

	bt_plugin_set_version(plugin, major, minor, patch, version_extra);

	if (PyList_Check(py_comp_class_addrs)) {
		size_t i;

		for (i = 0; i < PyList_Size(py_comp_class_addrs); i++) {
			struct bt_component_class *comp_class;
			PyObject *py_comp_class_addr;

			py_comp_class_addr =
				PyList_GetItem(py_comp_class_addrs, i);
			assert(py_comp_class_addr);
			if (PyLong_Check(py_comp_class_addr)) {
				comp_class = (struct bt_component_class *)
					PyLong_AsUnsignedLongLong(py_comp_class_addr);
			} else {
				printf_verbose("Component class address #%zu: not an integer\n",
					i);
				continue;
			}

			ret = bt_plugin_add_component_class(plugin, comp_class);
			if (ret < 0) {
				printf_verbose("Cannot add component class #%zu\n",
					i);
				continue;
			}
		}
	}

	bt_plugin_freeze(plugin);

	goto end;

error:
	print_python_traceback_verbose();
	pyerr_clear();
	BT_PUT(plugin);

end:
	Py_XDECREF(py_name);
	Py_XDECREF(py_author);
	Py_XDECREF(py_description);
	Py_XDECREF(py_license);
	Py_XDECREF(py_version);
	Py_XDECREF(py_comp_class_addrs);
	return plugin;
}

BT_HIDDEN
struct bt_plugin **bt_plugin_python_create_all_from_file(const char *path)
{
	struct bt_plugin **plugins = NULL;
	PyObject *py_plugin_info = NULL;
	gchar *basename = NULL;
	size_t path_len;

	assert(path);

	if (python_state == PYTHON_STATE_CANNOT_INITIALIZE) {
		/*
		 * We do not even care about the rest of the function
		 * here because we already know Python cannot be fully
		 * initialized.
		 */
		goto error;
	}

	path_len = strlen(path);

	/* File name ends with `.py` */
	if (strncmp(path + path_len - PYTHON_PLUGIN_FILE_EXT_LEN,
			PYTHON_PLUGIN_FILE_EXT,
			PYTHON_PLUGIN_FILE_EXT_LEN) != 0) {
		printf_verbose("Skipping non-Python file: `%s`\n",
			path);
		goto error;
	}

	/* File name starts with `bt_plugin_` */
	basename = g_path_get_basename(path);
	if (!basename) {
		goto error;
	}

	if (strncmp(basename, PYTHON_PLUGIN_FILE_PREFIX,
			PYTHON_PLUGIN_FILE_PREFIX_LEN) != 0) {
		printf_verbose("Skipping Python file not starting with `%s`: `%s`\n",
			PYTHON_PLUGIN_FILE_PREFIX, path);
		goto error;
	}

	/*
	 * Initialize Python now.
	 *
	 * This is not done in the library contructor because the
	 * interpreter is somewhat slow to initialize. If you don't
	 * have any potential Python plugins, you don't need to endure
	 * this waiting time everytime you load the library.
	 */
	init_python();
	if (python_state != PYTHON_STATE_FULLY_INITIALIZED) {
		/*
		 * For some reason we cannot initialize Python,
		 * import the required modules, and get the required
		 * attributes from them.
		 */
		goto error;
	}

	/*
	 * Call bt2.py_plugin._try_load_plugin_module() with this path
	 * to get plugin info if the plugin is loadable and complete.
	 * This function returns None when there's an error, but just in
	 * case we also manually clear the last Python error state.
	 */
	py_plugin_info = PyObject_CallFunction(py_try_load_plugin_module_func,
		"(s)", path);
	if (!py_plugin_info || py_plugin_info == Py_None) {
		printf_verbose("Cannot load Python plugin `%s`:\n", path);
		print_python_traceback_verbose();
		PyErr_Clear();
		goto error;
	}

	/*
	 * Get bt_plugin from plugin info object.
	 *
	 * calloc(2, ...) because a single Python plugin file always
	 * provides a single Babeltrace plugin (second item is the
	 * sentinel).
	 */
	plugins = calloc(2, sizeof(*plugins));
	if (!plugins) {
		goto error;
	}

	plugins[0] = bt_plugin_from_python_plugin_info(py_plugin_info);
	if (!plugins[0]) {
		goto error;
	}

	bt_plugin_set_path(plugins[0], path);
	goto end;

error:
	if (plugins) {
		BT_PUT(plugins[0]);
		free(plugins);
		plugins = NULL;
	}

end:
	Py_XDECREF(py_plugin_info);
	g_free(basename);
	return plugins;
}
Commit	Line	Data
55bb57e0 PP	1	/*
	2	* plugin-python.c
	3	*
	4	* Babeltrace Plugin (Python)
	5	*
	6	* Copyright 2017 Philippe Proulx <pproulx@efficios.com>
	7	*
	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this software and associated documentation files (the "Software"), to deal
	10	* in the Software without restriction, including without limitation the rights
	11	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	12	* copies of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be included in
	16	* all copies or substantial portions of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	21	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	22	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	23	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	24	* SOFTWARE.
	25	*/
	26
	27	#include <babeltrace/babeltrace-internal.h>
	28	#include <babeltrace/compiler.h>
	29	#include <babeltrace/ref.h>
	30	#include <babeltrace/plugin/plugin-internal.h>
	31	#include <babeltrace/plugin/plugin-internal.h>
	32	#include <babeltrace/component/component-class-internal.h>
	33	#include <stdlib.h>
	34	#include <signal.h>
	35	#include <Python.h>
	36
	37	#define PYTHON_PLUGIN_FILE_PREFIX "bt_plugin_"
	38	#define PYTHON_PLUGIN_FILE_PREFIX_LEN (sizeof(PYTHON_PLUGIN_FILE_PREFIX) - 1)
	39	#define PYTHON_PLUGIN_FILE_EXT ".py"
	40	#define PYTHON_PLUGIN_FILE_EXT_LEN (sizeof(PYTHON_PLUGIN_FILE_EXT) - 1)
	41
	42	enum python_state {
	43	/* init_python() not called yet */
	44	PYTHON_STATE_NOT_INITED,
	45
	46	/* init_python() called once with success */
	47	PYTHON_STATE_FULLY_INITIALIZED,
	48
	49	/* init_python() called once without success */
	50	PYTHON_STATE_CANNOT_INITIALIZE,
	51	} python_state = PYTHON_STATE_NOT_INITED;
	52
	53	static PyObject *py_try_load_plugin_module_func = NULL;
	54
	55	static
	56	void print_python_traceback_verbose(void)
	57	{
	58	if (Py_IsInitialized() && PyErr_Occurred() && babeltrace_verbose) {
	59	PyErr_Print();
	60	}
	61	}
	62
	63	static
	64	void pyerr_clear(void)
65	{
66	if (Py_IsInitialized()) {
67	PyErr_Clear();
68	}
69	}
70
71	static
72	void init_python(void)
73	{
74	PyObject *py_bt2_py_plugin_mod = NULL;
75	const char *dis_python_env;
76	sighandler_t old_sigint = signal(SIGINT, SIG_DFL);
77
78	if (python_state != PYTHON_STATE_NOT_INITED) {
79	goto end;
80	}
81
82	/*
83	* User can disable Python plugin support with the
84	* BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable set to
85	* 1.
86	*/
87	dis_python_env = getenv("BABELTRACE_DISABLE_PYTHON_PLUGINS");
88	if (dis_python_env && dis_python_env[0] == '1' &&
89	dis_python_env[1] == '\0') {
90	printf_verbose("Python plugin support is disabled by BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable\n");
91	python_state = PYTHON_STATE_CANNOT_INITIALIZE;
92	goto end;
93	}
94
95	if (!Py_IsInitialized()) {
96	Py_InitializeEx(0);
97	printf_verbose("Initialized Python:\n%s\n", Py_GetVersion());
98	}
99
100	py_bt2_py_plugin_mod = PyImport_ImportModule("bt2.py_plugin");
101	if (!py_bt2_py_plugin_mod) {
102	printf_verbose("Cannot import bt2.py_plugin Python module\n");
103	python_state = PYTHON_STATE_CANNOT_INITIALIZE;
104	goto end;
105	}
106
107	py_try_load_plugin_module_func =
108	PyObject_GetAttrString(py_bt2_py_plugin_mod, "_try_load_plugin_module");
109	if (!py_try_load_plugin_module_func) {
110	printf_verbose("Cannot get _try_load_plugin_module attribute from bt2.py_plugin Python module\n");
111	python_state = PYTHON_STATE_CANNOT_INITIALIZE;
112	goto end;
113	}
114
115	python_state = PYTHON_STATE_FULLY_INITIALIZED;
116
117	end:
118	if (old_sigint != SIG_ERR) {
119	(void) signal(SIGINT, old_sigint);
120	}
121
122	print_python_traceback_verbose();
123	pyerr_clear();
124	Py_XDECREF(py_bt2_py_plugin_mod);
125	return;
126	}
127
128	__attribute__((destructor)) static
129	void fini_python(void) {
130	if (Py_IsInitialized()) {
131	if (py_try_load_plugin_module_func) {
132	Py_DECREF(py_try_load_plugin_module_func);
133	py_try_load_plugin_module_func = NULL;
134	}
135
136	Py_Finalize();
137	}
138
139	python_state = PYTHON_STATE_NOT_INITED;
140	}
141
142	static
143	struct bt_plugin bt_plugin_from_python_plugin_info(PyObject plugin_info)
144	{
145	struct bt_plugin *plugin = NULL;
146	PyObject *py_name = NULL;
147	PyObject *py_author = NULL;
148	PyObject *py_description = NULL;
149	PyObject *py_license = NULL;
150	PyObject *py_version = NULL;
151	PyObject *py_comp_class_addrs = NULL;
152	const char *name = NULL;
153	const char *author = NULL;
154	const char *description = NULL;
155	const char *license = NULL;
156	unsigned int major = 0, minor = 0, patch = 0;
157	const char *version_extra = NULL;
158	int ret;
159
160	assert(plugin_info);
161	assert(python_state == PYTHON_STATE_FULLY_INITIALIZED);
162	py_name = PyObject_GetAttrString(plugin_info, "name");
163	if (!py_name) {
164	printf_verbose("Cannot find `name` attribute in plugin info\n");
165	goto error;
166	}
167
168	py_author = PyObject_GetAttrString(plugin_info, "author");
169	if (!py_author) {
170	printf_verbose("Cannot find `author` attribute in plugin info\n");
171	goto error;
172	}
173
174	py_description = PyObject_GetAttrString(plugin_info, "description");
175	if (!py_description) {
176	printf_verbose("Cannot find `description` attribute in plugin info\n");
177	goto error;
178	}
179
180	py_license = PyObject_GetAttrString(plugin_info, "license");
181	if (!py_license) {
182	printf_verbose("Cannot find `license` attribute in plugin info\n");
183	goto error;
184	}
185
186	py_version = PyObject_GetAttrString(plugin_info, "version");
187	if (!py_version) {
188	printf_verbose("Cannot find `version` attribute in plugin info\n");
189	goto error;
190	}
191
192	py_comp_class_addrs = PyObject_GetAttrString(plugin_info,
193	"comp_class_addrs");
194	if (!py_comp_class_addrs) {
195	printf_verbose("Cannot find `comp_class_addrs` attribute in plugin info\n");
196	goto error;
197	}
198
199	if (PyUnicode_Check(py_name)) {
200	name = PyUnicode_AsUTF8(py_name);
201	if (!name) {
202	printf_verbose("Cannot decode plugin name string\n");
203	goto error;
204	}
205	} else {
206	/* Plugin name is mandatory */
207	printf_verbose("Plugin name is not a string\n");
208	goto error;
209	}
210
211	if (PyUnicode_Check(py_author)) {
212	author = PyUnicode_AsUTF8(py_author);
213	if (!author) {
214	printf_verbose("Cannot decode plugin author string\n");
215	goto error;
216	}
217	}
218
219	if (PyUnicode_Check(py_description)) {
220	description = PyUnicode_AsUTF8(py_description);
221	if (!description) {
222	printf_verbose("Cannot decode plugin description string\n");
223	goto error;
224	}
225	}
226
227	if (PyUnicode_Check(py_license)) {
228	license = PyUnicode_AsUTF8(py_license);
229	if (!license) {
230	printf_verbose("Cannot decode plugin license string\n");
231	goto error;
232	}
233	}
234
235	if (PyTuple_Check(py_version)) {
236	if (PyTuple_Size(py_version) >= 3) {
237	PyObject *py_major = PyTuple_GetItem(py_version, 0);
238	PyObject *py_minor = PyTuple_GetItem(py_version, 1);
239	PyObject *py_patch = PyTuple_GetItem(py_version, 2);
240
241	assert(py_major);
242	assert(py_minor);
243	assert(py_patch);
244
245	if (PyLong_Check(py_major)) {
246	major = PyLong_AsUnsignedLong(py_major);
247	}
248
249	if (PyLong_Check(py_minor)) {
250	minor = PyLong_AsUnsignedLong(py_minor);
251	}
252
253	if (PyLong_Check(py_patch)) {
254	patch = PyLong_AsUnsignedLong(py_patch);
255	}
256
257	if (PyErr_Occurred()) {
258	/* Overflow error, most probably */
259	printf_verbose("Invalid plugin version format\n");
260	goto error;
261	}
262	}
263
264	if (PyTuple_Size(py_version) >= 4) {
265	PyObject *py_extra = PyTuple_GetItem(py_version, 3);
266
267	assert(py_extra);
268
269	if (PyUnicode_Check(py_extra)) {
270	version_extra = PyUnicode_AsUTF8(py_extra);
271	if (!version_extra) {
272	printf_verbose("Cannot decode plugin version's extra string\n");
273	goto error;
274	}
275	}
276	}
277	}
278
279	plugin = bt_plugin_create_empty(BT_PLUGIN_TYPE_PYTHON);
280	if (!plugin) {
281	goto error;
282	}
283
284	bt_plugin_set_name(plugin, name);
285
286	if (description) {
287	bt_plugin_set_description(plugin, description);
288	}
289
290	if (author) {
291	bt_plugin_set_author(plugin, author);
292	}
293
294	if (license) {
295	bt_plugin_set_license(plugin, license);
296	}
297
298	bt_plugin_set_version(plugin, major, minor, patch, version_extra);
299
300	if (PyList_Check(py_comp_class_addrs)) {
301	size_t i;
302
303	for (i = 0; i < PyList_Size(py_comp_class_addrs); i++) {
304	struct bt_component_class *comp_class;
305	PyObject *py_comp_class_addr;
306
307	py_comp_class_addr =
308	PyList_GetItem(py_comp_class_addrs, i);
309	assert(py_comp_class_addr);
310	if (PyLong_Check(py_comp_class_addr)) {
311	comp_class = (struct bt_component_class *)
312	PyLong_AsUnsignedLongLong(py_comp_class_addr);
313	} else {
314	printf_verbose("Component class address #%zu: not an integer\n",
315	i);
316	continue;
317	}
318
319	ret = bt_plugin_add_component_class(plugin, comp_class);
320	if (ret < 0) {
321	printf_verbose("Cannot add component class #%zu\n",
322	i);
323	continue;
324	}
325	}
326	}
327
328	bt_plugin_freeze(plugin);
329
330	goto end;
331
332	error:
333	print_python_traceback_verbose();
334	pyerr_clear();
335	BT_PUT(plugin);
336
337	end:
338	Py_XDECREF(py_name);
339	Py_XDECREF(py_author);
340	Py_XDECREF(py_description);
341	Py_XDECREF(py_license);
342	Py_XDECREF(py_version);
343	Py_XDECREF(py_comp_class_addrs);
344	return plugin;
345	}
346
347	BT_HIDDEN
348	struct bt_plugin *bt_plugin_python_create_all_from_file(const char path)
349	{
350	struct bt_plugin **plugins = NULL;
351	PyObject *py_plugin_info = NULL;
352	gchar *basename = NULL;
353	size_t path_len;
354
355	assert(path);
356
357	if (python_state == PYTHON_STATE_CANNOT_INITIALIZE) {
358	/*
359	* We do not even care about the rest of the function
360	* here because we already know Python cannot be fully
361	* initialized.
362	*/
363	goto error;
364	}
365
366	path_len = strlen(path);
367
368	/* File name ends with `.py` */
369	if (strncmp(path + path_len - PYTHON_PLUGIN_FILE_EXT_LEN,
370	PYTHON_PLUGIN_FILE_EXT,
371	PYTHON_PLUGIN_FILE_EXT_LEN) != 0) {
372	printf_verbose("Skipping non-Python file: `%s`\n",
373	path);
374	goto error;
375	}
376
377	/* File name starts with `bt_plugin_` */
378	basename = g_path_get_basename(path);
379	if (!basename) {
380	goto error;
381	}
382
383	if (strncmp(basename, PYTHON_PLUGIN_FILE_PREFIX,
384	PYTHON_PLUGIN_FILE_PREFIX_LEN) != 0) {
385	printf_verbose("Skipping Python file not starting with `%s`: `%s`\n",
386	PYTHON_PLUGIN_FILE_PREFIX, path);
387	goto error;
388	}
389
390	/*
391	* Initialize Python now.
392	*
393	* This is not done in the library contructor because the
394	* interpreter is somewhat slow to initialize. If you don't
395	* have any potential Python plugins, you don't need to endure
396	* this waiting time everytime you load the library.
397	*/
398	init_python();
399	if (python_state != PYTHON_STATE_FULLY_INITIALIZED) {
400	/*
401	* For some reason we cannot initialize Python,
402	* import the required modules, and get the required
403	* attributes from them.
404	*/
405	goto error;
406	}
407
408	/*
409	* Call bt2.py_plugin._try_load_plugin_module() with this path
410	* to get plugin info if the plugin is loadable and complete.
411	* This function returns None when there's an error, but just in
412	* case we also manually clear the last Python error state.
413	*/
414	py_plugin_info = PyObject_CallFunction(py_try_load_plugin_module_func,
415	"(s)", path);
416	if (!py_plugin_info \|\| py_plugin_info == Py_None) {
417	printf_verbose("Cannot load Python plugin `%s`:\n", path);
418	print_python_traceback_verbose();
419	PyErr_Clear();
420	goto error;
421	}
422
423	/*
424	* Get bt_plugin from plugin info object.
425	*
426	* calloc(2, ...) because a single Python plugin file always
427	* provides a single Babeltrace plugin (second item is the
428	* sentinel).
429	*/
430	plugins = calloc(2, sizeof(*plugins));
431	if (!plugins) {
432	goto error;
433	}
434
435	plugins[0] = bt_plugin_from_python_plugin_info(py_plugin_info);
436	if (!plugins[0]) {
437	goto error;
438	}
439
440	bt_plugin_set_path(plugins[0], path);
441	goto end;
442
443	error:
444	if (plugins) {
445	BT_PUT(plugins[0]);
446	free(plugins);
447	plugins = NULL;
448	}
449
450	end:
451	Py_XDECREF(py_plugin_info);
452	g_free(basename);
453	return plugins;
454	}