--- /dev/null
+/*
+ * 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;
+}
projects / babeltrace.git / blobdiff