Commit | Line | Data |
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7085eeaa | 1 | /* |
0235b0db MJ |
2 | * SPDX-License-Identifier: MIT |
3 | * | |
7085eeaa PP |
4 | * Copyright (c) 2019 EfficiOS Inc. and Linux Foundation |
5 | * Copyright (c) 2019 Philippe Proulx <pproulx@efficios.com> | |
6 | * Copyright (c) 2019 Simon Marchi <simon.marchi@efficios.com> | |
7085eeaa PP |
7 | */ |
8 | ||
9 | #define BT_LOG_OUTPUT_LEVEL log_level | |
10 | #define BT_LOG_TAG "PY-COMMON" | |
11 | #include "logging/log.h" | |
12 | ||
c4f23e30 FD |
13 | #include <stdbool.h> |
14 | ||
7085eeaa PP |
15 | #include <Python.h> |
16 | ||
17 | #include "common/assert.h" | |
18 | #include "py-common.h" | |
19 | ||
332c7e11 SM |
20 | /* |
21 | * Concatenate strings in list `py_str_list`, returning the result as a | |
22 | * GString. Remove the trailing \n, if the last string ends with a \n. | |
23 | */ | |
24 | static | |
25 | GString *py_str_list_to_gstring(PyObject *py_str_list, int log_level) | |
26 | { | |
27 | Py_ssize_t i; | |
28 | GString *gstr; | |
29 | ||
30 | gstr = g_string_new(NULL); | |
31 | if (!gstr) { | |
32 | BT_LOGE("Failed to allocate a GString."); | |
33 | goto end; | |
34 | } | |
35 | ||
36 | for (i = 0; i < PyList_Size(py_str_list); i++) { | |
37 | PyObject *py_str; | |
38 | const char *str; | |
39 | ||
40 | py_str = PyList_GetItem(py_str_list, i); | |
41 | BT_ASSERT(py_str); | |
42 | BT_ASSERT(PyUnicode_CheckExact(py_str)); | |
43 | ||
44 | /* `str` is owned by `py_str`, not by us */ | |
45 | str = PyUnicode_AsUTF8(py_str); | |
46 | if (!str) { | |
47 | if (BT_LOG_ON_ERROR) { | |
48 | BT_LOGE_STR("PyUnicode_AsUTF8() failed:"); | |
49 | PyErr_Print(); | |
50 | } | |
51 | ||
52 | goto error; | |
53 | } | |
54 | ||
55 | /* `str` has a trailing newline */ | |
56 | g_string_append(gstr, str); | |
57 | } | |
58 | ||
59 | if (gstr->len > 0) { | |
60 | /* Remove trailing newline if any */ | |
61 | if (gstr->str[gstr->len - 1] == '\n') { | |
62 | g_string_truncate(gstr, gstr->len - 1); | |
63 | } | |
64 | } | |
65 | ||
66 | goto end; | |
67 | ||
68 | error: | |
69 | g_string_free(gstr, TRUE); | |
70 | gstr = NULL; | |
71 | ||
72 | end: | |
73 | return gstr; | |
74 | } | |
75 | ||
76 | BT_HIDDEN | |
77 | GString *bt_py_common_format_tb(PyObject *py_exc_tb, int log_level) | |
78 | { | |
79 | PyObject *traceback_module = NULL; | |
80 | PyObject *format_tb_func = NULL; | |
81 | PyObject *exc_str_list = NULL; | |
82 | GString *msg_buf = NULL; | |
83 | ||
84 | BT_ASSERT(py_exc_tb); | |
85 | ||
86 | /* | |
87 | * Import the standard `traceback` module which contains the | |
88 | * functions to format a traceback. | |
89 | */ | |
90 | traceback_module = PyImport_ImportModule("traceback"); | |
91 | if (!traceback_module) { | |
92 | BT_LOGE_STR("Failed to import `traceback` module."); | |
93 | goto error; | |
94 | } | |
95 | ||
96 | format_tb_func = PyObject_GetAttrString(traceback_module, | |
97 | "format_tb"); | |
98 | if (!format_tb_func) { | |
99 | BT_LOGE("Cannot find `format_tb` attribute in `traceback` module."); | |
100 | goto error; | |
101 | } | |
102 | ||
103 | if (!PyCallable_Check(format_tb_func)) { | |
104 | BT_LOGE("`traceback.format_tb` attribute is not callable."); | |
105 | goto error; | |
106 | } | |
107 | ||
108 | /* | |
109 | * If we are calling format_exception_only, `py_exc_tb` is NULL, so the | |
110 | * effective argument list is of length 2. | |
111 | */ | |
112 | exc_str_list = PyObject_CallFunctionObjArgs( | |
113 | format_tb_func, py_exc_tb, NULL); | |
114 | if (!exc_str_list) { | |
115 | if (BT_LOG_ON_ERROR) { | |
116 | BT_LOGE("Failed to call `traceback.format_tb` function:"); | |
117 | PyErr_Print(); | |
118 | } | |
119 | ||
120 | goto error; | |
121 | } | |
122 | ||
123 | msg_buf = py_str_list_to_gstring(exc_str_list, log_level); | |
124 | if (!msg_buf) { | |
125 | goto error; | |
126 | } | |
127 | ||
332c7e11 | 128 | error: |
332c7e11 SM |
129 | Py_XDECREF(traceback_module); |
130 | Py_XDECREF(format_tb_func); | |
131 | Py_XDECREF(exc_str_list); | |
132 | ||
133 | return msg_buf; | |
134 | } | |
135 | ||
7085eeaa | 136 | BT_HIDDEN |
cacd0713 SM |
137 | GString *bt_py_common_format_exception(PyObject *py_exc_type, |
138 | PyObject *py_exc_value, PyObject *py_exc_tb, | |
139 | int log_level, bool chain) | |
7085eeaa | 140 | { |
7085eeaa PP |
141 | PyObject *traceback_module = NULL; |
142 | PyObject *format_exception_func = NULL; | |
143 | PyObject *exc_str_list = NULL; | |
144 | GString *msg_buf = NULL; | |
145 | const char *format_exc_func_name; | |
7085eeaa | 146 | |
7085eeaa PP |
147 | /* |
148 | * Import the standard `traceback` module which contains the | |
149 | * functions to format an exception. | |
150 | */ | |
151 | traceback_module = PyImport_ImportModule("traceback"); | |
152 | if (!traceback_module) { | |
153 | BT_LOGE_STR("Failed to import `traceback` module."); | |
154 | goto error; | |
155 | } | |
156 | ||
157 | /* | |
cacd0713 | 158 | * `py_exc_tb` can be `NULL`, when we fail to call a Python |
7085eeaa PP |
159 | * function from native code (there is no Python stack at that |
160 | * point). For example, a function which takes 5 positional | |
161 | * arguments, but 8 were given. | |
162 | */ | |
cacd0713 | 163 | format_exc_func_name = py_exc_tb ? "format_exception" : |
7085eeaa PP |
164 | "format_exception_only"; |
165 | format_exception_func = PyObject_GetAttrString(traceback_module, | |
166 | format_exc_func_name); | |
167 | if (!format_exception_func) { | |
168 | BT_LOGE("Cannot find `%s` attribute in `traceback` module.", | |
169 | format_exc_func_name); | |
170 | goto error; | |
171 | } | |
172 | ||
173 | if (!PyCallable_Check(format_exception_func)) { | |
174 | BT_LOGE("`traceback.%s` attribute is not callable.", | |
175 | format_exc_func_name); | |
176 | goto error; | |
177 | } | |
178 | ||
cacd0713 SM |
179 | /* |
180 | * If we are calling format_exception_only, `py_exc_tb` is NULL, so the | |
181 | * effective argument list is of length 2. | |
182 | */ | |
7085eeaa | 183 | exc_str_list = PyObject_CallFunctionObjArgs(format_exception_func, |
cacd0713 SM |
184 | py_exc_type, py_exc_value, py_exc_tb, Py_None /* limit */, |
185 | chain ? Py_True : Py_False /* chain */, NULL); | |
7085eeaa PP |
186 | if (!exc_str_list) { |
187 | if (BT_LOG_ON_ERROR) { | |
188 | BT_LOGE("Failed to call `traceback.%s` function:", | |
189 | format_exc_func_name); | |
190 | PyErr_Print(); | |
191 | } | |
192 | ||
193 | goto error; | |
194 | } | |
195 | ||
332c7e11 SM |
196 | msg_buf = py_str_list_to_gstring(exc_str_list, log_level); |
197 | if (!msg_buf) { | |
198 | goto error; | |
7085eeaa PP |
199 | } |
200 | ||
7085eeaa | 201 | error: |
7085eeaa PP |
202 | Py_XDECREF(exc_str_list); |
203 | Py_XDECREF(format_exception_func); | |
204 | Py_XDECREF(traceback_module); | |
205 | ||
cacd0713 SM |
206 | return msg_buf; |
207 | } | |
208 | ||
209 | BT_HIDDEN | |
210 | GString *bt_py_common_format_current_exception(int log_level) | |
211 | { | |
212 | GString *result; | |
213 | PyObject *py_exc_type = NULL; | |
214 | PyObject *py_exc_value = NULL; | |
215 | PyObject *py_exc_tb = NULL; | |
216 | ||
217 | BT_ASSERT(PyErr_Occurred()); | |
218 | PyErr_Fetch(&py_exc_type, &py_exc_value, &py_exc_tb); | |
219 | BT_ASSERT(py_exc_type); | |
220 | ||
221 | /* | |
222 | * Make sure `py_exc_value` is what we expected: an instance of | |
223 | * `py_exc_type`. | |
224 | */ | |
225 | PyErr_NormalizeException(&py_exc_type, &py_exc_value, &py_exc_tb); | |
226 | ||
227 | result = bt_py_common_format_exception(py_exc_type, py_exc_value, | |
228 | py_exc_tb, log_level, true); | |
229 | ||
7085eeaa PP |
230 | /* |
231 | * We can safely call PyErr_Restore() because we always call | |
232 | * PyErr_Fetch(), and having an error indicator is a function's | |
233 | * precondition. | |
234 | * | |
235 | * PyErr_Restore() steals our references. | |
236 | */ | |
cacd0713 | 237 | PyErr_Restore(py_exc_type, py_exc_value, py_exc_tb); |
7085eeaa | 238 | |
cacd0713 | 239 | return result; |
7085eeaa | 240 | } |