]> sigrok.org Git - libsigrokdecode.git/blame - decoder.c
srd: simplified error checking, in preparation for more of it
[libsigrokdecode.git] / decoder.c
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1/*
2 * This file is part of the sigrok project.
3 *
4 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
5 * Copyright (C) 2011 Bert Vermeulen <bert@biot.com>
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
64c29e28 21#include <glib.h>
b2c19614 22#include "config.h"
73191416 23#include "sigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
15969949 24#include "sigrokdecode-internal.h"
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25
26/* The list of protocol decoders. */
e5080882 27GSList *pd_list = NULL;
b2c19614 28
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29/* lives in module_sigrokdecode.c */
30extern PyObject *mod_sigrokdecode;
31
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32
33/**
34 * Returns the list of supported/loaded protocol decoders.
35 *
36 * This is a GSList containing the names of the decoders as strings.
37 *
38 * @return List of decoders, NULL if none are supported or loaded.
39 */
40GSList *srd_list_decoders(void)
41{
42
e5080882 43 return pd_list;
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44}
45
46
47/**
48 * Get the decoder with the specified ID.
49 *
50 * @param id The ID string of the decoder to return.
51 * @return The decoder with the specified ID, or NULL if not found.
52 */
53struct srd_decoder *srd_get_decoder_by_id(const char *id)
54{
55 GSList *l;
56 struct srd_decoder *dec;
57
58 for (l = srd_list_decoders(); l; l = l->next) {
59 dec = l->data;
60 if (!strcmp(dec->id, id))
61 return dec;
62 }
63
64 return NULL;
65}
66
67
68/**
64c29e28 69 * Load a protocol decoder module into the embedded Python interpreter.
b2c19614 70 *
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71 * @param name The module name to be loaded.
72 * @param dec Pointer to the struct srd_decoder filled with the loaded module.
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73 *
74 * @return SRD_OK upon success, a (negative) error code otherwise.
75 */
76int srd_load_decoder(const char *name, struct srd_decoder **dec)
77{
451680f1 78 PyObject *py_basedec, *py_annlist, *py_ann;
b2c19614 79 struct srd_decoder *d;
451680f1 80 int alen, ret, i;
15969949 81 char **ann;
b2c19614 82
451680f1 83 py_basedec = NULL;
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84
85 srd_dbg("decoder: %s: loading module '%s'", __func__, name);
b2c19614 86
451680f1 87 if (!(d = g_try_malloc0(sizeof(struct srd_decoder)))) {
64c29e28 88 srd_err("decoder: %s: d malloc failed", __func__);
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89 ret = SRD_ERR_MALLOC;
90 goto err_out;
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91 }
92
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93 ret = SRD_ERR_PYTHON;
94
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95 /* Import the Python module. */
96 if (!(d->py_mod = PyImport_ImportModule(name))) {
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97 /* TODO: Report exception message/traceback to err/dbg. */
98 srd_warn("decoder: %s: import of '%s' failed", __func__, name);
99 PyErr_Print();
451680f1 100 PyErr_Clear();
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101 goto err_out;
102 }
b2c19614 103
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104 /* Get the 'Decoder' class as Python object. */
105 if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
106 /* This generated an AttributeError exception. */
64c29e28 107 PyErr_Print();
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108 PyErr_Clear();
109 srd_err("Decoder class not found in protocol decoder module %s", name);
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110 goto err_out;
111 }
b2c19614 112
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113 if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
114 srd_dbg("sigrokdecode module not loaded");
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115 goto err_out;
116 }
b2c19614 117
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118 if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
119 srd_err("Decoder class in protocol decoder module %s is not "
120 "a subclass of sigrokdecode.Decoder", name);
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121 goto err_out;
122 }
123 Py_DecRef(py_basedec);
b2c19614 124
21481b66 125 if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
451680f1 126 goto err_out;
b2c19614 127
21481b66 128 if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
451680f1 129 goto err_out;
b2c19614 130
21481b66 131 if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
451680f1 132 goto err_out;
b2c19614 133
21481b66 134 if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
451680f1 135 goto err_out;
b2c19614 136
21481b66 137 if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
451680f1 138 goto err_out;
b2c19614 139
451680f1 140 /* TODO: Handle inputformats, outputformats. */
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141 d->inputformats = NULL;
142 d->outputformats = NULL;
143
15969949 144 /* Convert class annotation attribute to GSList of **char */
e97b6ef5 145 d->annotations = NULL;
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146 if (PyObject_HasAttrString(d->py_dec, "annotations")) {
147 py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
15969949 148 if (!PyList_Check(py_annlist)) {
e97b6ef5 149 srd_err("Protocol decoder module %s annotations should be a list", name);
451680f1 150 goto err_out;
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151 }
152 alen = PyList_Size(py_annlist);
153 for (i = 0; i < alen; i++) {
154 py_ann = PyList_GetItem(py_annlist, i);
155 if (!PyList_Check(py_ann) || PyList_Size(py_ann) != 2) {
156 srd_err("Protocol decoder module %s annotation %d should be a list with two elements",
157 name, i+1);
451680f1 158 goto err_out;
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159 }
160
451680f1 161 if (py_strlist_to_char(py_ann, &ann) != SRD_OK) {
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162 goto err_out;
163 }
e97b6ef5 164 d->annotations = g_slist_append(d->annotations, ann);
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165 }
166 }
167
b2c19614 168 *dec = d;
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169 ret = SRD_OK;
170
171err_out:
172 if (ret != SRD_OK) {
173 Py_XDECREF(py_basedec);
174 Py_XDECREF(d->py_dec);
175 Py_XDECREF(d->py_mod);
176 g_free(d);
177 }
b2c19614 178
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179 return ret;
180}
181
182char *srd_decoder_doc(struct srd_decoder *dec)
183{
e7edca07 184 PyObject *py_str;
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185 char *doc;
186
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187 if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
188 return NULL;
189
190 if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
191 PyErr_Clear();
192 return NULL;
193 }
194
451680f1 195 doc = NULL;
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196 if (py_str != Py_None)
197 py_str_as_str(py_str, &doc);
198 Py_DecRef(py_str);
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199
200 return doc;
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201}
202
203
204/**
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205 * Unload decoder module.
206 *
207 * @param dec The decoder struct to be unloaded.
208 *
209 * @return SRD_OK upon success, a (negative) error code otherwise.
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210 */
211int srd_unload_decoder(struct srd_decoder *dec)
212{
451680f1 213
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214 g_free(dec->id);
215 g_free(dec->name);
b231546d 216 g_free(dec->longname);
b2c19614 217 g_free(dec->desc);
b231546d 218 g_free(dec->license);
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219
220 /* TODO: Free everything in inputformats and outputformats. */
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221 if (dec->inputformats != NULL)
222 g_slist_free(dec->inputformats);
223 if (dec->outputformats != NULL)
224 g_slist_free(dec->outputformats);
225
451680f1 226 Py_XDECREF(dec->py_dec);
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227 Py_XDECREF(dec->py_mod);
228
229 /* TODO: (g_)free dec itself? */
230
231 return SRD_OK;
232}
233
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234/**
235 * Check if the directory in the specified search path is a valid PD dir.
236 *
237 * A valid sigrok protocol decoder consists of a directory, which contains
238 * at least two .py files (the special __init__.py and at least one additional
239 * .py file which contains the actual PD code).
240 *
241 * TODO: We should also check that this is not a random other Python module,
242 * but really a sigrok PD module by some means.
243 *
244 * @param search_path A string containing the (absolute) path to the directory
245 * where 'entry' resides in.
246 * @param entry A string containing the (relative) directory name of the
247 * sigrok PD module. E.g. "i2c" for the I2C protocol decoder.
248 * @return SRD_OK, if the directory is a valid sigrok PD, a negative error
249 * code, such as SRD_ERR, otherwise.
250 */
251int srd_is_valid_pd_dir(const gchar *search_path, const gchar *entry)
252{
253 GDir *dir;
254 int py_files = 0, has_init_py = 0;
255 gchar *path1, *path2, *file;
256 GError *error;
257
258 /* TODO: Error handling. */
259 path1 = g_build_filename(search_path, entry, NULL);
260
261 /* Check that it is a directory (and exists). */
262 if (!g_file_test(path1, G_FILE_TEST_IS_DIR)) {
263 srd_dbg("decoder: %s: '%s' not a directory or doesn't exist",
264 __func__, entry);
265 return SRD_ERR;
266 }
267
268 if (!(dir = g_dir_open(path1, 0, &error))) { /* TODO: flags? */
269 srd_dbg("decoder: %s: '%s' failed to open directory",
270 __func__, entry);
271 return SRD_ERR;
272 }
273
274 /* Check the contents of the directory. */
275 while ((file = g_dir_read_name(dir)) != NULL) {
276 /* TODO: Error handling. */
277 path2 = g_build_filename(path1, file, NULL);
278
279 /* Ignore non-files. */
280 if (!g_file_test(path2, G_FILE_TEST_IS_REGULAR)) {
281 srd_spew("decoder: %s: '%s' not a file, ignoring",
282 __func__, file);
283 continue;
284 }
285
286 /* Count number of .py files. */
287 if (g_str_has_suffix(path2, ".py")) {
288 srd_spew("decoder: %s: found .py file: '%s'",
289 __func__, file);
290 py_files++;
291 }
292
293 /* Check if it's an __init__.py file. */
294 if (g_str_has_suffix(path2, "__init__.py")) {
295 srd_spew("decoder: %s: found __init__.py file: '%s'",
296 __func__, path2);
297 has_init_py = 1;
298 }
299 }
300 g_dir_close(dir);
301
302 /* Check if the directory contains >= 2 *.py files. */
303 if (py_files < 2) {
304 srd_dbg("decoder: %s: '%s' is not a valid PD dir, it doesn't "
305 "contain >= 2 .py files", __func__, entry);
306 return SRD_ERR;
307 }
308
309 /* Check if the directory contains an __init__.py file. */
310 if (!has_init_py) {
311 srd_dbg("decoder: %s: '%s' is not a valid PD dir, it doesn't "
312 "contain an __init__.py file", __func__, entry);
313 return SRD_ERR;
314 }
315
316 /* TODO: Check if it's a PD, not a random other Python module. */
317
318 return SRD_OK;
319}
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320
321int srd_load_all_decoders(void)
322{
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323 GDir *dir;
324 gchar *direntry;
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325 int ret;
326 char *decodername;
327 struct srd_decoder *dec;
64c29e28 328 GError *error;
b2c19614 329
64c29e28 330 if (!(dir = g_dir_open(DECODERS_DIR, 0, &error))) { /* TODO: flags? */
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331 Py_Finalize(); /* Returns void. */
332 return SRD_ERR_DECODERS_DIR;
333 }
334
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335 while ((direntry = g_dir_read_name(dir)) != NULL) {
336 /* Ignore directory entries which are not valid PDs. */
337 if (srd_is_valid_pd_dir(DECODERS_DIR, direntry) != SRD_OK) {
338 srd_dbg("decoder: %s: '%s' not a valid PD dir, "
339 "ignoring it", __func__, direntry);
b2c19614 340 continue;
64c29e28 341 }
b2c19614 342
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343 /* The decoder name is the PD directory name (e.g. "i2c"). */
344 decodername = g_strdup(direntry);
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345
346 /* TODO: Error handling. Use g_try_malloc(). */
347 if (!(dec = malloc(sizeof(struct srd_decoder)))) {
348 Py_Finalize(); /* Returns void. */
349 return SRD_ERR_MALLOC;
350 }
351
352 /* Load the decoder. */
353 /* TODO: Warning if loading fails for a decoder. */
354 if ((ret = srd_load_decoder(decodername, &dec)) == SRD_OK) {
355 /* Append it to the list of supported/loaded decoders. */
e5080882 356 pd_list = g_slist_append(pd_list, dec);
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357 }
358 }
64c29e28 359 g_dir_close(dir);
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360
361 return SRD_OK;
362}
363
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364/**
365 * TODO
366 */
367int srd_unload_all_decoders(void)
368{
369 GSList *l;
370 struct srd_decoder *dec;
371
372 for (l = srd_list_decoders(); l; l = l->next) {
373 dec = l->data;
374 /* TODO: Error handling. */
375 srd_unload_decoder(dec);
376 }
377
378 return SRD_OK;
379}
380
381
382