-/*
- * 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;
-}