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         Py_ssize_t i;
 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 (i = 0; i < PyList_Size(py_list); i++) {
 143                 ret = py_listitem_as_str(py_list, i, &outstr);
 144                 if (ret < 0) {
 145                         srd_dbg("Couldn't get item %" PY_FORMAT_SIZE_T "d.", i);
 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         PyObject *py_value;
 221         PyGILState_STATE gstate;
 222
 223         gstate = PyGILState_Ensure();
 224
 225         if (!PyList_Check(py_obj)) {
 226                 srd_dbg("Object is not a list.");
 227                 goto err;
 228         }
 229
 230         if (!(py_value = PyList_GetItem(py_obj, idx))) {
 231                 srd_dbg("Couldn't get list item %" PY_FORMAT_SIZE_T "d.", idx);
 232                 goto err;
 233         }
 234
 235         PyGILState_Release(gstate);
 236
 237         return py_str_as_str(py_value, outstr);
 238
 239 err:
 240         PyGILState_Release(gstate);
 241
 242         return SRD_ERR_PYTHON;
 243 }
 244
 245 /**
 246  * Get the value of a Python dictionary item, returned as a newly
 247  * allocated char *.
 248  *
 249  * @param py_obj The dictionary to probe.
 250  * @param py_key Key of the item to retrieve.
 251  * @param outstr Pointer to char * storage to be filled in.
 252  *
 253  * @return SRD_OK upon success, a (negative) error code otherwise.
 254  *         The 'outstr' argument points to a malloc()ed string upon success.
 255  *
 256  * @private
 257  */
 258 SRD_PRIV int py_pydictitem_as_str(PyObject *py_obj, PyObject *py_key,
 259                                 char **outstr)
 260 {
 261         PyObject *py_value;
 262         PyGILState_STATE gstate;
 263
 264         if (!py_obj || !py_key || !outstr)
 265                 return SRD_ERR_ARG;
 266
 267         gstate = PyGILState_Ensure();
 268
 269         if (!PyDict_Check(py_obj)) {
 270                 srd_dbg("Object is not a dictionary.");
 271                 goto err;
 272         }
 273
 274         if (!(py_value = PyDict_GetItem(py_obj, py_key))) {
 275                 srd_dbg("Dictionary has no such key.");
 276                 goto err;
 277         }
 278
 279         if (!PyUnicode_Check(py_value)) {
 280                 srd_dbg("Dictionary value should be a string.");
 281                 goto err;
 282         }
 283
 284         PyGILState_Release(gstate);
 285
 286         return py_str_as_str(py_value, outstr);
 287
 288 err:
 289         PyGILState_Release(gstate);
 290
 291         return SRD_ERR_PYTHON;
 292 }
 293
 294 /**
 295  * Get the value of a Python dictionary item, returned as a newly
 296  * allocated char *.
 297  *
 298  * @param py_obj The dictionary to probe.
 299  * @param py_key Key of the item to retrieve.
 300  * @param out TODO.
 301  *
 302  * @return SRD_OK upon success, a (negative) error code otherwise.
 303  *
 304  * @private
 305  */
 306 SRD_PRIV int py_pydictitem_as_long(PyObject *py_obj, PyObject *py_key, int64_t *out)
 307 {
 308         PyObject *py_value;
 309         PyGILState_STATE gstate;
 310
 311         if (!py_obj || !py_key || !out)
 312                 return SRD_ERR_ARG;
 313
 314         gstate = PyGILState_Ensure();
 315
 316         if (!PyDict_Check(py_obj)) {
 317                 srd_dbg("Object is not a dictionary.");
 318                 goto err;
 319         }
 320
 321         if (!(py_value = PyDict_GetItem(py_obj, py_key))) {
 322                 srd_dbg("Dictionary has no such key.");
 323                 goto err;
 324         }
 325
 326         if (!PyLong_Check(py_value)) {
 327                 srd_dbg("Dictionary value should be a long.");
 328                 goto err;
 329         }
 330
 331         *out = PyLong_AsLongLong(py_value);
 332
 333         PyGILState_Release(gstate);
 334
 335         return SRD_OK;
 336
 337 err:
 338         PyGILState_Release(gstate);
 339
 340         return SRD_ERR_PYTHON;
 341 }
 342
 343 /**
 344  * Get the value of a Python unicode string object, returned as a newly
 345  * allocated char *.
 346  *
 347  * @param[in] py_str The unicode string object.
 348  * @param[out] outstr ptr to char * storage to be filled in.
 349  *
 350  * @return SRD_OK upon success, a (negative) error code otherwise.
 351  *         The 'outstr' argument points to a g_malloc()ed string upon success.
 352  *
 353  * @private
 354  */
 355 SRD_PRIV int py_str_as_str(PyObject *py_str, char **outstr)
 356 {
 357         PyObject *py_bytes;
 358         char *str;
 359         PyGILState_STATE gstate;
 360
 361         gstate = PyGILState_Ensure();
 362
 363         if (!PyUnicode_Check(py_str)) {
 364                 srd_dbg("Object is not a string object.");
 365                 PyGILState_Release(gstate);
 366                 return SRD_ERR_PYTHON;
 367         }
 368
 369         py_bytes = PyUnicode_AsUTF8String(py_str);
 370         if (py_bytes) {
 371                 str = g_strdup(PyBytes_AsString(py_bytes));
 372                 Py_DECREF(py_bytes);
 373                 if (str) {
 374                         *outstr = str;
 375                         PyGILState_Release(gstate);
 376                         return SRD_OK;
 377                 }
 378         }
 379         srd_exception_catch("Failed to extract string");
 380
 381         PyGILState_Release(gstate);
 382
 383         return SRD_ERR_PYTHON;
 384 }
 385
 386 /**
 387  * Convert a Python list of unicode strings to a C string vector.
 388  * On success, a pointer to a newly allocated NUL-terminated array of
 389  * allocated C strings is written to @a out_strv. The caller must g_free()
 390  * each string and the array itself.
 391  *
 392  * @param[in] py_strseq The sequence object.
 393  * @param[out] out_strv Address of string vector to be filled in.
 394  *
 395  * @return SRD_OK upon success, a (negative) error code otherwise.
 396  *
 397  * @private
 398  */
 399 SRD_PRIV int py_strseq_to_char(PyObject *py_strseq, char ***out_strv)
 400 {
 401         PyObject *py_item, *py_bytes;
 402         char **strv, *str;
 403         ssize_t seq_len, i;
 404         PyGILState_STATE gstate;
 405         int ret = SRD_ERR_PYTHON;
 406
 407         gstate = PyGILState_Ensure();
 408
 409         if (!PySequence_Check(py_strseq)) {
 410                 srd_err("Object does not provide sequence protocol.");
 411                 goto err;
 412         }
 413
 414         seq_len = PySequence_Size(py_strseq);
 415         if (seq_len < 0) {
 416                 srd_exception_catch("Failed to obtain sequence size");
 417                 goto err;
 418         }
 419
 420         strv = g_try_new0(char *, seq_len + 1);
 421         if (!strv) {
 422                 srd_err("Failed to allocate result string vector.");
 423                 ret = SRD_ERR_MALLOC;
 424                 goto err;
 425         }
 426
 427         for (i = 0; i < seq_len; i++) {
 428                 py_item = PySequence_GetItem(py_strseq, i);
 429                 if (!py_item)
 430                         goto err_out;
 431
 432                 if (!PyUnicode_Check(py_item)) {
 433                         Py_DECREF(py_item);
 434                         goto err_out;
 435                 }
 436                 py_bytes = PyUnicode_AsUTF8String(py_item);
 437                 Py_DECREF(py_item);
 438                 if (!py_bytes)
 439                         goto err_out;
 440
 441                 str = g_strdup(PyBytes_AsString(py_bytes));
 442                 Py_DECREF(py_bytes);
 443                 if (!str)
 444                         goto err_out;
 445
 446                 strv[i] = str;
 447         }
 448         *out_strv = strv;
 449
 450         PyGILState_Release(gstate);
 451
 452         return SRD_OK;
 453
 454 err_out:
 455         g_strfreev(strv);
 456         srd_exception_catch("Failed to obtain string item");
 457
 458 err:
 459         PyGILState_Release(gstate);
 460
 461         return ret;
 462 }
 463
 464 /**
 465  * Convert a Python scalar object to a GLib variant.
 466  * Supported variant types are string, int64 and double.
 467  *
 468  * @param[in] py_obj The Python object. Must not be NULL.
 469  * @return A floating reference to a new variant, or NULL on failure.
 470  *
 471  * @private
 472  */
 473 SRD_PRIV GVariant *py_obj_to_variant(PyObject *py_obj)
 474 {
 475         GVariant *var = NULL;
 476         PyGILState_STATE gstate;
 477
 478         gstate = PyGILState_Ensure();
 479
 480         if (PyUnicode_Check(py_obj)) { /* string */
 481                 PyObject *py_bytes;
 482                 const char *str;
 483
 484                 py_bytes = PyUnicode_AsUTF8String(py_obj);
 485                 if (py_bytes) {
 486                         str = PyBytes_AsString(py_bytes);
 487                         if (str)
 488                                 var = g_variant_new_string(str);
 489                         Py_DECREF(py_bytes);
 490                 }
 491                 if (!var)
 492                         srd_exception_catch("Failed to extract string value");
 493         } else if (PyLong_Check(py_obj)) { /* integer */
 494                 int64_t val;
 495
 496                 val = PyLong_AsLongLong(py_obj);
 497                 if (!PyErr_Occurred())
 498                         var = g_variant_new_int64(val);
 499                 else
 500                         srd_exception_catch("Failed to extract integer value");
 501         } else if (PyFloat_Check(py_obj)) { /* float */
 502                 double val;
 503
 504                 val = PyFloat_AsDouble(py_obj);
 505                 if (!PyErr_Occurred())
 506                         var = g_variant_new_double(val);
 507                 else
 508                         srd_exception_catch("Failed to extract float value");
 509         } else {
 510                 srd_err("Failed to extract value of unsupported type.");
 511         }
 512
 513         PyGILState_Release(gstate);
 514
 515         return var;
 516 }