util.c

   1 /*
   2  * This file is part of the libsigrokdecode project.
   3  *
   4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
   5  * Copyright (C) 2012 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
  21 #include <config.h>
  22 #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
  23
  24 /**
  25  * Import a Python module by name.
  26  *
  27  * This function is implemented in terms of PyImport_Import() rather than
  28  * PyImport_ImportModule(), so that the import hooks are not bypassed.
  29  *
  30  * @param[in] name The name of the module to load as UTF-8 string.
  31  * @return The Python module object, or NULL if an exception occurred. The
  32  *  caller is responsible for evaluating and clearing the Python error state.
  33  *
  34  * @private
  35  */
  36 SRD_PRIV PyObject *py_import_by_name(const char *name)
  37 {
  38         PyObject *py_mod, *py_modname;
  39         PyGILState_STATE gstate;
  40
  41         gstate = PyGILState_Ensure();
  42
  43         py_modname = PyUnicode_FromString(name);
  44         if (!py_modname) {
  45                 PyGILState_Release(gstate);
  46                 return NULL;
  47         }
  48
  49         py_mod = PyImport_Import(py_modname);
  50         Py_DECREF(py_modname);
  51
  52         PyGILState_Release(gstate);
  53
  54         return py_mod;
  55 }
  56
  57 /**
  58  * Get the value of a Python object's attribute, returned as a newly
  59  * allocated char *.
  60  *
  61  * @param[in] py_obj The object to probe.
  62  * @param[in] attr Name of the attribute to retrieve.
  63  * @param[out] outstr ptr to char * storage to be filled in.
  64  *
  65  * @return SRD_OK upon success, a (negative) error code otherwise.
  66  *         The 'outstr' argument points to a g_malloc()ed string upon success.
  67  *
  68  * @private
  69  */
  70 SRD_PRIV int py_attr_as_str(PyObject *py_obj, const char *attr, char **outstr)
  71 {
  72         PyObject *py_str;
  73         int ret;
  74         PyGILState_STATE gstate;
  75
  76         gstate = PyGILState_Ensure();
  77
  78         if (!PyObject_HasAttrString(py_obj, attr)) {
  79                 srd_dbg("Object has no attribute '%s'.", attr);
  80                 goto err;
  81         }
  82
  83         if (!(py_str = PyObject_GetAttrString(py_obj, attr))) {
  84                 srd_exception_catch("Failed to get attribute '%s'", attr);
  85                 goto err;
  86         }
  87
  88         ret = py_str_as_str(py_str, outstr);
  89         Py_DECREF(py_str);
  90
  91         PyGILState_Release(gstate);
  92
  93         return ret;
  94
  95 err:
  96         PyGILState_Release(gstate);
  97
  98         return SRD_ERR_PYTHON;
  99 }
 100
 101 /**
 102  * Get the value of a Python object's attribute, returned as a newly
 103  * allocated GSList of char *.
 104  *
 105  * @param[in] py_obj The object to probe.
 106  * @param[in] attr Name of the attribute to retrieve.
 107  * @param[out] outstrlist ptr to GSList of char * storage to be filled in.
 108  *
 109  * @return SRD_OK upon success, a (negative) error code otherwise.
 110  *         The 'outstrlist' argument points to a GSList of g_malloc()ed strings
 111  *         upon success.
 112  *
 113  * @private
 114  */
 115 SRD_PRIV int py_attr_as_strlist(PyObject *py_obj, const char *attr, GSList **outstrlist)
 116 {
 117         PyObject *py_list;
 118         ssize_t idx;
 119         int ret;
 120         char *outstr;
 121         PyGILState_STATE gstate;
 122
 123         gstate = PyGILState_Ensure();
 124
 125         if (!PyObject_HasAttrString(py_obj, attr)) {
 126                 srd_dbg("Object has no attribute '%s'.", attr);
 127                 goto err;
 128         }
 129
 130         if (!(py_list = PyObject_GetAttrString(py_obj, attr))) {
 131                 srd_exception_catch("Failed to get attribute '%s'", attr);
 132                 goto err;
 133         }
 134
 135         if (!PyList_Check(py_list)) {
 136                 srd_dbg("Object is not a list.");
 137                 goto err;
 138         }
 139
 140         *outstrlist = NULL;
 141
 142         for (idx = 0; idx < PyList_Size(py_list); idx++) {
 143                 ret = py_listitem_as_str(py_list, idx, &outstr);
 144                 if (ret < 0) {
 145                         srd_dbg("Couldn't get item %zd.", idx);
 146                         goto err;
 147                 }
 148                 *outstrlist = g_slist_append(*outstrlist, outstr);
 149         }
 150
 151         Py_DECREF(py_list);
 152
 153         PyGILState_Release(gstate);
 154
 155         return SRD_OK;
 156
 157 err:
 158         PyGILState_Release(gstate);
 159
 160         return SRD_ERR_PYTHON;
 161 }
 162
 163 /**
 164  * Get the value of a Python dictionary item, returned as a newly
 165  * allocated char *.
 166  *
 167  * @param[in] py_obj The dictionary to probe.
 168  * @param[in] key Key of the item to retrieve.
 169  * @param[out] outstr Pointer to char * storage to be filled in.
 170  *
 171  * @return SRD_OK upon success, a (negative) error code otherwise.
 172  *         The 'outstr' argument points to a g_malloc()ed string upon success.
 173  *
 174  * @private
 175  */
 176 SRD_PRIV int py_dictitem_as_str(PyObject *py_obj, const char *key,
 177                                 char **outstr)
 178 {
 179         PyObject *py_value;
 180         PyGILState_STATE gstate;
 181
 182         gstate = PyGILState_Ensure();
 183
 184         if (!PyDict_Check(py_obj)) {
 185                 srd_dbg("Object is not a dictionary.");
 186                 goto err;
 187         }
 188
 189         if (!(py_value = PyDict_GetItemString(py_obj, key))) {
 190                 srd_dbg("Dictionary has no attribute '%s'.", key);
 191                 goto err;
 192         }
 193
 194         PyGILState_Release(gstate);
 195
 196         return py_str_as_str(py_value, outstr);
 197
 198 err:
 199         PyGILState_Release(gstate);
 200
 201         return SRD_ERR_PYTHON;
 202 }
 203
 204 /**
 205  * Get the value of a Python list item, returned as a newly
 206  * allocated char *.
 207  *
 208  * @param[in] py_obj The list to probe.
 209  * @param[in] idx Index of the list item to retrieve.
 210  * @param[out] outstr Pointer to char * storage to be filled in.
 211  *
 212  * @return SRD_OK upon success, a (negative) error code otherwise.
 213  *         The 'outstr' argument points to a g_malloc()ed string upon success.
 214  *
 215  * @private
 216  */
 217 SRD_PRIV int py_listitem_as_str(PyObject *py_obj, Py_ssize_t idx,
 218                                 char **outstr)
 219 {
 220         PyGILState_STATE gstate;
 221         ssize_t item_idx;
 222         PyObject *py_value;
 223
 224         gstate = PyGILState_Ensure();
 225
 226         if (!PyList_Check(py_obj)) {
 227                 srd_dbg("Object is not a list.");
 228                 goto err;
 229         }
 230
 231         item_idx = idx;
 232         if (!(py_value = PyList_GetItem(py_obj, item_idx))) {
 233                 srd_dbg("Couldn't get list item %zd.", item_idx);
 234                 goto err;
 235         }
 236
 237         PyGILState_Release(gstate);
 238
 239         return py_str_as_str(py_value, outstr);
 240
 241 err:
 242         PyGILState_Release(gstate);
 243
 244         return SRD_ERR_PYTHON;
 245 }
 246
 247 /**
 248  * Get the value of a Python dictionary item, returned as a newly
 249  * allocated char *.
 250  *
 251  * @param py_obj The dictionary to probe.
 252  * @param py_key Key of the item to retrieve.
 253  * @param outstr Pointer to char * storage to be filled in.
 254  *
 255  * @return SRD_OK upon success, a (negative) error code otherwise.
 256  *         The 'outstr' argument points to a malloc()ed string upon success.
 257  *
 258  * @private
 259  */
 260 SRD_PRIV int py_pydictitem_as_str(PyObject *py_obj, PyObject *py_key,
 261                                 char **outstr)
 262 {
 263         PyObject *py_value;
 264         PyGILState_STATE gstate;
 265
 266         if (!py_obj || !py_key || !outstr)
 267                 return SRD_ERR_ARG;
 268
 269         gstate = PyGILState_Ensure();
 270
 271         if (!PyDict_Check(py_obj)) {
 272                 srd_dbg("Object is not a dictionary.");
 273                 goto err;
 274         }
 275
 276         if (!(py_value = PyDict_GetItem(py_obj, py_key))) {
 277                 srd_dbg("Dictionary has no such key.");
 278                 goto err;
 279         }
 280
 281         if (!PyUnicode_Check(py_value)) {
 282                 srd_dbg("Dictionary value should be a string.");
 283                 goto err;
 284         }
 285
 286         PyGILState_Release(gstate);
 287
 288         return py_str_as_str(py_value, outstr);
 289
 290 err:
 291         PyGILState_Release(gstate);
 292
 293         return SRD_ERR_PYTHON;
 294 }
 295
 296 /**
 297  * Get the value of a Python dictionary item, returned as a newly
 298  * allocated char *.
 299  *
 300  * @param py_obj The dictionary to probe.
 301  * @param py_key Key of the item to retrieve.
 302  * @param out TODO.
 303  *
 304  * @return SRD_OK upon success, a (negative) error code otherwise.
 305  *
 306  * @private
 307  */
 308 SRD_PRIV int py_pydictitem_as_long(PyObject *py_obj, PyObject *py_key, int64_t *out)
 309 {
 310         PyObject *py_value;
 311         PyGILState_STATE gstate;
 312
 313         if (!py_obj || !py_key || !out)
 314                 return SRD_ERR_ARG;
 315
 316         gstate = PyGILState_Ensure();
 317
 318         if (!PyDict_Check(py_obj)) {
 319                 srd_dbg("Object is not a dictionary.");
 320                 goto err;
 321         }
 322
 323         if (!(py_value = PyDict_GetItem(py_obj, py_key))) {
 324                 srd_dbg("Dictionary has no such key.");
 325                 goto err;
 326         }
 327
 328         if (!PyLong_Check(py_value)) {
 329                 srd_dbg("Dictionary value should be a long.");
 330                 goto err;
 331         }
 332
 333         *out = PyLong_AsLongLong(py_value);
 334
 335         PyGILState_Release(gstate);
 336
 337         return SRD_OK;
 338
 339 err:
 340         PyGILState_Release(gstate);
 341
 342         return SRD_ERR_PYTHON;
 343 }
 344
 345 /**
 346  * Get the value of a Python unicode string object, returned as a newly
 347  * allocated char *.
 348  *
 349  * @param[in] py_str The unicode string object.
 350  * @param[out] outstr ptr to char * storage to be filled in.
 351  *
 352  * @return SRD_OK upon success, a (negative) error code otherwise.
 353  *         The 'outstr' argument points to a g_malloc()ed string upon success.
 354  *
 355  * @private
 356  */
 357 SRD_PRIV int py_str_as_str(PyObject *py_str, char **outstr)
 358 {
 359         PyObject *py_bytes;
 360         char *str;
 361         PyGILState_STATE gstate;
 362
 363         gstate = PyGILState_Ensure();
 364
 365         if (!PyUnicode_Check(py_str)) {
 366                 srd_dbg("Object is not a string object.");
 367                 PyGILState_Release(gstate);
 368                 return SRD_ERR_PYTHON;
 369         }
 370
 371         py_bytes = PyUnicode_AsUTF8String(py_str);
 372         if (py_bytes) {
 373                 str = g_strdup(PyBytes_AsString(py_bytes));
 374                 Py_DECREF(py_bytes);
 375                 if (str) {
 376                         *outstr = str;
 377                         PyGILState_Release(gstate);
 378                         return SRD_OK;
 379                 }
 380         }
 381         srd_exception_catch("Failed to extract string");
 382
 383         PyGILState_Release(gstate);
 384
 385         return SRD_ERR_PYTHON;
 386 }
 387
 388 /**
 389  * Convert a Python list of unicode strings to a C string vector.
 390  * On success, a pointer to a newly allocated NUL-terminated array of
 391  * allocated C strings is written to @a out_strv. The caller must g_free()
 392  * each string and the array itself.
 393  *
 394  * @param[in] py_strseq The sequence object.
 395  * @param[out] out_strv Address of string vector to be filled in.
 396  *
 397  * @return SRD_OK upon success, a (negative) error code otherwise.
 398  *
 399  * @private
 400  */
 401 SRD_PRIV int py_strseq_to_char(PyObject *py_strseq, char ***out_strv)
 402 {
 403         PyObject *py_item, *py_bytes;
 404         char **strv, *str;
 405         ssize_t seq_len, i;
 406         PyGILState_STATE gstate;
 407         int ret = SRD_ERR_PYTHON;
 408
 409         gstate = PyGILState_Ensure();
 410
 411         if (!PySequence_Check(py_strseq)) {
 412                 srd_err("Object does not provide sequence protocol.");
 413                 goto err;
 414         }
 415
 416         seq_len = PySequence_Size(py_strseq);
 417         if (seq_len < 0) {
 418                 srd_exception_catch("Failed to obtain sequence size");
 419                 goto err;
 420         }
 421
 422         strv = g_try_new0(char *, seq_len + 1);
 423         if (!strv) {
 424                 srd_err("Failed to allocate result string vector.");
 425                 ret = SRD_ERR_MALLOC;
 426                 goto err;
 427         }
 428
 429         for (i = 0; i < seq_len; i++) {
 430                 py_item = PySequence_GetItem(py_strseq, i);
 431                 if (!py_item)
 432                         goto err_out;
 433
 434                 if (!PyUnicode_Check(py_item)) {
 435                         Py_DECREF(py_item);
 436                         goto err_out;
 437                 }
 438                 py_bytes = PyUnicode_AsUTF8String(py_item);
 439                 Py_DECREF(py_item);
 440                 if (!py_bytes)
 441                         goto err_out;
 442
 443                 str = g_strdup(PyBytes_AsString(py_bytes));
 444                 Py_DECREF(py_bytes);
 445                 if (!str)
 446                         goto err_out;
 447
 448                 strv[i] = str;
 449         }
 450         *out_strv = strv;
 451
 452         PyGILState_Release(gstate);
 453
 454         return SRD_OK;
 455
 456 err_out:
 457         g_strfreev(strv);
 458         srd_exception_catch("Failed to obtain string item");
 459
 460 err:
 461         PyGILState_Release(gstate);
 462
 463         return ret;
 464 }
 465
 466 /**
 467  * Convert a Python scalar object to a GLib variant.
 468  * Supported variant types are string, int64 and double.
 469  *
 470  * @param[in] py_obj The Python object. Must not be NULL.
 471  * @return A floating reference to a new variant, or NULL on failure.
 472  *
 473  * @private
 474  */
 475 SRD_PRIV GVariant *py_obj_to_variant(PyObject *py_obj)
 476 {
 477         GVariant *var = NULL;
 478         PyGILState_STATE gstate;
 479
 480         gstate = PyGILState_Ensure();
 481
 482         if (PyUnicode_Check(py_obj)) { /* string */
 483                 PyObject *py_bytes;
 484                 const char *str;
 485
 486                 py_bytes = PyUnicode_AsUTF8String(py_obj);
 487                 if (py_bytes) {
 488                         str = PyBytes_AsString(py_bytes);
 489                         if (str)
 490                                 var = g_variant_new_string(str);
 491                         Py_DECREF(py_bytes);
 492                 }
 493                 if (!var)
 494                         srd_exception_catch("Failed to extract string value");
 495         } else if (PyLong_Check(py_obj)) { /* integer */
 496                 int64_t val;
 497
 498                 val = PyLong_AsLongLong(py_obj);
 499                 if (!PyErr_Occurred())
 500                         var = g_variant_new_int64(val);
 501                 else
 502                         srd_exception_catch("Failed to extract integer value");
 503         } else if (PyFloat_Check(py_obj)) { /* float */
 504                 double val;
 505
 506                 val = PyFloat_AsDouble(py_obj);
 507                 if (!PyErr_Occurred())
 508                         var = g_variant_new_double(val);
 509                 else
 510                         srd_exception_catch("Failed to extract float value");
 511         } else {
 512                 srd_err("Failed to extract value of unsupported type.");
 513         }
 514
 515         PyGILState_Release(gstate);
 516
 517         return var;
 518 }