Proper exception logging.

diff --git a/src/python.c b/src/python.c
index a68e374..fe8144a 100644 (file)
--- a/src/python.c
+++ b/src/python.c
@@ -26,6 +26,8 @@ static int do_interactive = 0;
 
 static PyThreadState *state;
 
+static PyObject *cpy_format_exception;
+
 static cpy_callback_t *cpy_config_callbacks;
 static cpy_callback_t *cpy_init_callbacks;
 static cpy_callback_t *cpy_shutdown_callbacks;
@@ -73,6 +75,56 @@ static void cpy_build_name(char *buf, size_t size, PyObject *callback, const cha
        Py_XDECREF(n);
 }
 
+static void cpy_log_exception(const char *context) {
+       int l = 0, i;
+       const char *typename = NULL, *message = NULL;
+       PyObject *type, *value, *traceback, *tn, *m, *list;
+       
+       PyErr_Fetch(&type, &value, &traceback);
+       PyErr_NormalizeException(&type, &value, &traceback);
+       if (type == NULL) return;
+       tn = PyObject_GetAttrString(type, "__name__"); /* New reference. */
+       m = PyObject_GetAttrString(value, "message"); /* New reference. */
+       if (tn != NULL)
+               typename = PyString_AsString(tn);
+       if (m != NULL)
+               message = PyString_AsString(m);
+       if (typename == NULL)
+               typename = "NamelessException";
+       if (message == NULL)
+               message = "N/A";
+       ERROR("Unhandled python exception in %s: %s: %s", context, typename, message);
+       Py_XDECREF(tn);
+       Py_XDECREF(m);
+       if (!cpy_format_exception) {
+               PyErr_Clear();
+               Py_XDECREF(type);
+               Py_XDECREF(value);
+               Py_XDECREF(traceback);
+               return;
+       }
+       if (!traceback) {
+               PyErr_Clear();
+               return;
+       }
+       list = PyObject_CallFunction(cpy_format_exception, "NNN", type, value, traceback);
+       if (list)
+               l = PyObject_Length(list);
+       for (i = 0; i < l; ++i) {
+               char *s;
+               PyObject *line;
+               
+               line = PyList_GET_ITEM(list, i);
+               s = strdup(PyString_AsString(line));
+               Py_DECREF(line);
+               if (s[strlen(s) - 1] == '\n')
+                       s[strlen(s) - 1] = 0;
+               ERROR("%s", s);
+               free(s);
+       }
+       PyErr_Clear();
+}
+
 static int cpy_read_callback(user_data_t *data) {
        cpy_callback_t *c = data->data;
        PyObject *ret;
@@ -80,8 +132,7 @@ static int cpy_read_callback(user_data_t *data) {
        CPY_LOCK_THREADS
                ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
                if (ret == NULL) {
-                       /* FIXME */
-                       PyErr_Print();
+                       cpy_log_exception("read callback");
                } else {
                        Py_DECREF(ret);
                }
@@ -97,7 +148,7 @@ static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_li
        CPY_LOCK_THREADS
                list = PyList_New(value_list->values_len); /* New reference. */
                if (list == NULL) {
-                       PyErr_Print();
+                       cpy_log_exception("write callback");
                        CPY_RETURN_FROM_THREADS 0;
                }
                for (i = 0; i < value_list->values_len; ++i) {
@@ -124,7 +175,7 @@ static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_li
                                CPY_RETURN_FROM_THREADS 0;
                        }
                        if (PyErr_Occurred() != NULL) {
-                               PyErr_Print();
+                               cpy_log_exception("value building for write callback");
                                CPY_RETURN_FROM_THREADS 0;
                        }
                }
@@ -134,8 +185,7 @@ static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_li
                Py_DECREF(list);
                ret = PyObject_CallFunctionObjArgs(c->callback, v, c->data, (void *) 0); /* New reference. */
                if (ret == NULL) {
-                       /* FIXME */
-                       PyErr_Print();
+                       cpy_log_exception("write callback");
                } else {
                        Py_DECREF(ret);
                }
@@ -155,6 +205,8 @@ static void cpy_log_callback(int severity, const char *message, user_data_t *dat
 
        if (ret == NULL) {
                /* FIXME */
+               /* Do we really want to trigger a log callback because a log callback failed?
+                * Probably not. */
                PyErr_Print();
        } else {
                Py_DECREF(ret);
@@ -351,7 +403,7 @@ static int cpy_shutdown(void) {
        for (c = cpy_shutdown_callbacks; c; c = c->next) {
                ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
                if (ret == NULL)
-                       PyErr_Print(); /* FIXME */
+                       cpy_log_exception("shutdown callback");
                else
                        Py_DECREF(ret);
        }
@@ -363,7 +415,7 @@ static void *cpy_interactive(void *data) {
        CPY_LOCK_THREADS
                if (PyImport_ImportModule("readline") == NULL) {
                        /* This interactive session will suck. */
-                       PyErr_Print(); /* FIXME */
+                       cpy_log_exception("interactive session init");
                }
                PyRun_InteractiveLoop(stdin, "<stdin>");
        CPY_RELEASE_THREADS
@@ -382,7 +434,7 @@ static int cpy_init(void) {
        for (c = cpy_init_callbacks; c; c = c->next) {
                ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
                if (ret == NULL)
-                       PyErr_Print(); /* FIXME */
+                       cpy_log_exception("init callback");
                else
                        Py_DECREF(ret);
        }
@@ -429,7 +481,7 @@ static PyObject *cpy_oconfig_to_pyconfig(oconfig_item_t *ci, PyObject *parent) {
 
 static int cpy_config(oconfig_item_t *ci) {
        int i;
-       PyObject *sys;
+       PyObject *sys, *tb;
        PyObject *sys_path;
        PyObject *module;
        
@@ -445,16 +497,13 @@ static int cpy_config(oconfig_item_t *ci) {
        PyType_Ready(&ValuesType);
        sys = PyImport_ImportModule("sys"); /* New reference. */
        if (sys == NULL) {
-               ERROR("python module: Unable to import \"sys\" module.");
-               /* Just print the default python exception text to stderr. */
-               PyErr_Print();
+               cpy_log_exception("python initialization");
                return 1;
        }
        sys_path = PyObject_GetAttrString(sys, "path"); /* New reference. */
        Py_DECREF(sys);
        if (sys_path == NULL) {
-               ERROR("python module: Unable to read \"sys.path\".");
-               PyErr_Print();
+               cpy_log_exception("python initialization");
                return 1;
        }
        module = Py_InitModule("collectd", cpy_methods); /* Borrowed reference. */
@@ -469,10 +518,28 @@ static int cpy_config(oconfig_item_t *ci) {
                oconfig_item_t *item = ci->children + i;
                
                if (strcasecmp(item->key, "Interactive") == 0) {
-                       if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN ||
-                                       !item->values[0].value.boolean)
+                       if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
+                               continue;
+                       do_interactive = item->values[0].value.boolean;
+               } else if (strcasecmp(item->key, "LogTraces") == 0) {
+                       if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
+                               continue;
+                       if (!item->values[0].value.boolean) {
+                               Py_XDECREF(cpy_format_exception);
+                               cpy_format_exception = NULL;
+                               continue;
+                       }
+                       if (cpy_format_exception)
                                continue;
-                       do_interactive = 1;
+                       tb = PyImport_ImportModule("traceback"); /* New reference. */
+                       if (tb == NULL) {
+                               cpy_log_exception("python initialization");
+                               continue;
+                       }
+                       cpy_format_exception = PyObject_GetAttrString(tb, "format_exception"); /* New reference. */
+                       Py_DECREF(tb);
+                       if (cpy_format_exception == NULL)
+                               cpy_log_exception("python initialization");
                } else if (strcasecmp(item->key, "ModulePath") == 0) {
                        char *dir = NULL;
                        PyObject *dir_object;
@@ -484,13 +551,13 @@ static int cpy_config(oconfig_item_t *ci) {
                                ERROR("python plugin: Unable to convert \"%s\" to "
                                      "a python object.", dir);
                                free(dir);
-                               PyErr_Print();
+                               cpy_log_exception("python initialization");
                                continue;
                        }
                        if (PyList_Append(sys_path, dir_object) != 0) {
                                ERROR("python plugin: Unable to append \"%s\" to "
                                      "python module path.", dir);
-                               PyErr_Print();
+                               cpy_log_exception("python initialization");
                        }
                        Py_DECREF(dir_object);
                        free(dir);
@@ -503,6 +570,7 @@ static int cpy_config(oconfig_item_t *ci) {
                        module = PyImport_ImportModule(module_name); /* New reference. */
                        if (module == NULL) {
                                ERROR("python plugin: Error importing module \"%s\".", module_name);
+                               cpy_log_exception("python initialization");
                                PyErr_Print();
                        }
                        free(module_name);
@@ -533,7 +601,7 @@ static int cpy_config(oconfig_item_t *ci) {
                                ret = PyObject_CallFunction(c->callback, "NO",
                                        cpy_oconfig_to_pyconfig(item, NULL), c->data); /* New reference. */
                        if (ret == NULL)
-                               PyErr_Print();
+                               cpy_log_exception("loading module");
                        else
                                Py_DECREF(ret);
                } else {