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757bf1df | 1 | /* A state machine for detecting misuses of the malloc/free API. |
99dee823 | 2 | Copyright (C) 2019-2021 Free Software Foundation, Inc. |
757bf1df DM |
3 | Contributed by David Malcolm <dmalcolm@redhat.com>. |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tree.h" | |
25 | #include "function.h" | |
26 | #include "basic-block.h" | |
27 | #include "gimple.h" | |
28 | #include "options.h" | |
29 | #include "bitmap.h" | |
30 | #include "diagnostic-path.h" | |
31 | #include "diagnostic-metadata.h" | |
32 | #include "function.h" | |
809192e7 | 33 | #include "json.h" |
757bf1df DM |
34 | #include "analyzer/analyzer.h" |
35 | #include "diagnostic-event-id.h" | |
36 | #include "analyzer/analyzer-logging.h" | |
37 | #include "analyzer/sm.h" | |
38 | #include "analyzer/pending-diagnostic.h" | |
808f4dfe DM |
39 | #include "tristate.h" |
40 | #include "selftest.h" | |
41 | #include "analyzer/call-string.h" | |
42 | #include "analyzer/program-point.h" | |
43 | #include "analyzer/store.h" | |
44 | #include "analyzer/region-model.h" | |
c7e276b8 DM |
45 | #include "stringpool.h" |
46 | #include "attribs.h" | |
cd323d97 | 47 | #include "analyzer/function-set.h" |
757bf1df DM |
48 | |
49 | #if ENABLE_ANALYZER | |
50 | ||
75038aa6 DM |
51 | namespace ana { |
52 | ||
757bf1df DM |
53 | namespace { |
54 | ||
c7e276b8 DM |
55 | /* This state machine and its various support classes track allocations |
56 | and deallocations. | |
57 | ||
58 | It has a few standard allocation/deallocation pairs (e.g. new/delete), | |
59 | and also supports user-defined ones via | |
60 | __attribute__ ((malloc(DEALLOCATOR))). | |
61 | ||
62 | There can be more than one valid deallocator for a given allocator, | |
63 | for example: | |
64 | __attribute__ ((malloc (fclose))) | |
65 | __attribute__ ((malloc (freopen, 3))) | |
66 | FILE* fopen (const char*, const char*); | |
67 | A deallocator_set represents a particular set of valid deallocators. | |
68 | ||
69 | We track the expected deallocator_set for a value, but not the allocation | |
70 | function - there could be more than one allocator per deallocator_set. | |
71 | For example, there could be dozens of allocators for "free" beyond just | |
72 | malloc e.g. calloc, xstrdup, etc. We don't want to explode the number | |
73 | of states by tracking individual allocators in the exploded graph; | |
74 | we merely want to track "this value expects to have 'free' called on it". | |
75 | Perhaps we can reconstruct which allocator was used later, when emitting | |
76 | the path, if it's necessary for precision of wording of diagnostics. */ | |
77 | ||
78 | class deallocator; | |
79 | class deallocator_set; | |
1690a839 DM |
80 | class malloc_state_machine; |
81 | ||
82 | /* An enum for discriminating between different kinds of allocation_state. */ | |
83 | ||
84 | enum resource_state | |
85 | { | |
c7e276b8 | 86 | /* States that are independent of allocator/deallocator. */ |
1690a839 DM |
87 | |
88 | /* The start state. */ | |
89 | RS_START, | |
90 | ||
91 | /* State for a pointer that's known to be NULL. */ | |
92 | RS_NULL, | |
93 | ||
94 | /* State for a pointer that's known to not be on the heap (e.g. to a local | |
95 | or global). */ | |
96 | RS_NON_HEAP, | |
97 | ||
98 | /* Stop state, for pointers we don't want to track any more. */ | |
99 | RS_STOP, | |
100 | ||
c7e276b8 | 101 | /* States that relate to a specific deallocator_set. */ |
1690a839 | 102 | |
c7e276b8 | 103 | /* State for a pointer returned from an allocator that hasn't |
1690a839 DM |
104 | been checked for NULL. |
105 | It could be a pointer to heap-allocated memory, or could be NULL. */ | |
106 | RS_UNCHECKED, | |
107 | ||
c7e276b8 | 108 | /* State for a pointer returned from an allocator, |
1690a839 DM |
109 | known to be non-NULL. */ |
110 | RS_NONNULL, | |
111 | ||
c7e276b8 | 112 | /* State for a pointer passed to a deallocator. */ |
1690a839 DM |
113 | RS_FREED |
114 | }; | |
115 | ||
c7e276b8 DM |
116 | /* Custom state subclass, which can optionally refer to an a |
117 | deallocator_set. */ | |
1690a839 DM |
118 | |
119 | struct allocation_state : public state_machine::state | |
120 | { | |
121 | allocation_state (const char *name, unsigned id, | |
c7e276b8 DM |
122 | enum resource_state rs, |
123 | const deallocator_set *deallocators, | |
124 | const deallocator *deallocator) | |
125 | : state (name, id), m_rs (rs), | |
126 | m_deallocators (deallocators), | |
127 | m_deallocator (deallocator) | |
1690a839 DM |
128 | {} |
129 | ||
130 | void dump_to_pp (pretty_printer *pp) const FINAL OVERRIDE; | |
131 | ||
132 | const allocation_state *get_nonnull () const; | |
133 | ||
134 | enum resource_state m_rs; | |
c7e276b8 DM |
135 | const deallocator_set *m_deallocators; |
136 | const deallocator *m_deallocator; | |
1690a839 DM |
137 | }; |
138 | ||
139 | /* An enum for choosing which wording to use in various diagnostics | |
140 | when describing deallocations. */ | |
141 | ||
142 | enum wording | |
143 | { | |
144 | WORDING_FREED, | |
c7e276b8 | 145 | WORDING_DELETED, |
a6baafca DM |
146 | WORDING_DEALLOCATED, |
147 | WORDING_REALLOCATED | |
1690a839 DM |
148 | }; |
149 | ||
c7e276b8 DM |
150 | /* Base class representing a deallocation function, |
151 | either a built-in one we know about, or one exposed via | |
152 | __attribute__((malloc(DEALLOCATOR))). */ | |
1690a839 | 153 | |
c7e276b8 | 154 | struct deallocator |
1690a839 | 155 | { |
c7e276b8 DM |
156 | hashval_t hash () const; |
157 | void dump_to_pp (pretty_printer *pp) const; | |
158 | static int cmp (const deallocator *a, const deallocator *b); | |
159 | static int cmp_ptr_ptr (const void *, const void *); | |
1690a839 | 160 | |
c7e276b8 | 161 | /* Name to use in diagnostics. */ |
1690a839 DM |
162 | const char *m_name; |
163 | ||
c7e276b8 DM |
164 | /* Which wording to use in diagnostics. */ |
165 | enum wording m_wording; | |
166 | ||
167 | /* State for a value passed to one of the deallocators. */ | |
168 | state_machine::state_t m_freed; | |
169 | ||
170 | protected: | |
171 | deallocator (malloc_state_machine *sm, | |
172 | const char *name, | |
173 | enum wording wording); | |
174 | }; | |
175 | ||
176 | /* Subclass representing a predefined deallocator. | |
177 | e.g. "delete []", without needing a specific FUNCTION_DECL | |
178 | ahead of time. */ | |
179 | ||
180 | struct standard_deallocator : public deallocator | |
181 | { | |
182 | standard_deallocator (malloc_state_machine *sm, | |
183 | const char *name, | |
184 | enum wording wording); | |
185 | }; | |
186 | ||
187 | /* Subclass representing a user-defined deallocator | |
188 | via __attribute__((malloc(DEALLOCATOR))) given | |
189 | a specific FUNCTION_DECL. */ | |
190 | ||
191 | struct custom_deallocator : public deallocator | |
192 | { | |
193 | custom_deallocator (malloc_state_machine *sm, | |
194 | tree deallocator_fndecl, | |
195 | enum wording wording) | |
196 | : deallocator (sm, IDENTIFIER_POINTER (DECL_NAME (deallocator_fndecl)), | |
197 | wording) | |
198 | { | |
199 | } | |
200 | }; | |
201 | ||
202 | /* Base class representing a set of possible deallocators. | |
203 | Often this will be just a single deallocator, but some | |
204 | allocators have multiple valid deallocators (e.g. the result of | |
205 | "fopen" can be closed by either "fclose" or "freopen"). */ | |
206 | ||
207 | struct deallocator_set | |
208 | { | |
209 | deallocator_set (malloc_state_machine *sm, | |
210 | enum wording wording); | |
211 | virtual ~deallocator_set () {} | |
212 | ||
213 | virtual bool contains_p (const deallocator *d) const = 0; | |
214 | virtual const deallocator *maybe_get_single () const = 0; | |
215 | virtual void dump_to_pp (pretty_printer *pp) const = 0; | |
216 | void dump () const; | |
1690a839 DM |
217 | |
218 | /* Which wording to use in diagnostics. */ | |
219 | enum wording m_wording; | |
220 | ||
c7e276b8 | 221 | /* Pointers to states. |
1690a839 DM |
222 | These states are owned by the state_machine base class. */ |
223 | ||
c7e276b8 | 224 | /* State for an unchecked result from an allocator using this set. */ |
1690a839 DM |
225 | state_machine::state_t m_unchecked; |
226 | ||
c7e276b8 | 227 | /* State for a known non-NULL result from such an allocator. */ |
1690a839 | 228 | state_machine::state_t m_nonnull; |
c7e276b8 | 229 | }; |
1690a839 | 230 | |
c7e276b8 DM |
231 | /* Subclass of deallocator_set representing a set of deallocators |
232 | defined by one or more __attribute__((malloc(DEALLOCATOR))). */ | |
233 | ||
234 | struct custom_deallocator_set : public deallocator_set | |
235 | { | |
236 | typedef const auto_vec <const deallocator *> *key_t; | |
237 | ||
238 | custom_deallocator_set (malloc_state_machine *sm, | |
239 | const auto_vec <const deallocator *> *vec, | |
240 | //const char *name, | |
241 | //const char *dealloc_funcname, | |
242 | //unsigned arg_idx, | |
243 | enum wording wording); | |
244 | ||
245 | bool contains_p (const deallocator *d) const FINAL OVERRIDE; | |
246 | const deallocator *maybe_get_single () const FINAL OVERRIDE; | |
247 | void dump_to_pp (pretty_printer *pp) const FINAL OVERRIDE; | |
248 | ||
249 | auto_vec <const deallocator *> m_deallocator_vec; | |
250 | }; | |
251 | ||
252 | /* Subclass of deallocator_set representing a set of deallocators | |
253 | with a single standard_deallocator, e.g. "delete []". */ | |
254 | ||
255 | struct standard_deallocator_set : public deallocator_set | |
256 | { | |
257 | standard_deallocator_set (malloc_state_machine *sm, | |
258 | const char *name, | |
259 | enum wording wording); | |
260 | ||
261 | bool contains_p (const deallocator *d) const FINAL OVERRIDE; | |
262 | const deallocator *maybe_get_single () const FINAL OVERRIDE; | |
263 | void dump_to_pp (pretty_printer *pp) const FINAL OVERRIDE; | |
264 | ||
265 | standard_deallocator m_deallocator; | |
266 | }; | |
267 | ||
268 | /* Traits class for ensuring uniqueness of deallocator_sets within | |
269 | malloc_state_machine. */ | |
270 | ||
271 | struct deallocator_set_map_traits | |
272 | { | |
273 | typedef custom_deallocator_set::key_t key_type; | |
274 | typedef custom_deallocator_set *value_type; | |
275 | typedef custom_deallocator_set *compare_type; | |
276 | ||
277 | static inline hashval_t hash (const key_type &k) | |
278 | { | |
279 | gcc_assert (k != NULL); | |
280 | gcc_assert (k != reinterpret_cast<key_type> (1)); | |
281 | ||
282 | hashval_t result = 0; | |
283 | unsigned i; | |
284 | const deallocator *d; | |
285 | FOR_EACH_VEC_ELT (*k, i, d) | |
286 | result ^= d->hash (); | |
287 | return result; | |
288 | } | |
289 | static inline bool equal_keys (const key_type &k1, const key_type &k2) | |
290 | { | |
291 | if (k1->length () != k2->length ()) | |
292 | return false; | |
293 | ||
294 | for (unsigned i = 0; i < k1->length (); i++) | |
295 | if ((*k1)[i] != (*k2)[i]) | |
296 | return false; | |
297 | ||
298 | return true; | |
299 | } | |
300 | template <typename T> | |
301 | static inline void remove (T &) | |
302 | { | |
303 | /* empty; the nodes are handled elsewhere. */ | |
304 | } | |
305 | template <typename T> | |
306 | static inline void mark_deleted (T &entry) | |
307 | { | |
308 | entry.m_key = reinterpret_cast<key_type> (1); | |
309 | } | |
310 | template <typename T> | |
311 | static inline void mark_empty (T &entry) | |
312 | { | |
313 | entry.m_key = NULL; | |
314 | } | |
315 | template <typename T> | |
316 | static inline bool is_deleted (const T &entry) | |
317 | { | |
318 | return entry.m_key == reinterpret_cast<key_type> (1); | |
319 | } | |
320 | template <typename T> | |
321 | static inline bool is_empty (const T &entry) | |
322 | { | |
323 | return entry.m_key == NULL; | |
324 | } | |
325 | static const bool empty_zero_p = false; | |
1690a839 DM |
326 | }; |
327 | ||
757bf1df DM |
328 | /* A state machine for detecting misuses of the malloc/free API. |
329 | ||
330 | See sm-malloc.dot for an overview (keep this in-sync with that file). */ | |
331 | ||
332 | class malloc_state_machine : public state_machine | |
333 | { | |
334 | public: | |
1690a839 DM |
335 | typedef allocation_state custom_data_t; |
336 | ||
757bf1df | 337 | malloc_state_machine (logger *logger); |
c7e276b8 | 338 | ~malloc_state_machine (); |
757bf1df | 339 | |
1690a839 | 340 | state_t |
c7e276b8 DM |
341 | add_state (const char *name, enum resource_state rs, |
342 | const deallocator_set *deallocators, | |
343 | const deallocator *deallocator); | |
1690a839 | 344 | |
757bf1df DM |
345 | bool inherited_state_p () const FINAL OVERRIDE { return false; } |
346 | ||
808f4dfe DM |
347 | state_machine::state_t |
348 | get_default_state (const svalue *sval) const FINAL OVERRIDE | |
349 | { | |
350 | if (tree cst = sval->maybe_get_constant ()) | |
351 | { | |
352 | if (zerop (cst)) | |
353 | return m_null; | |
354 | } | |
355 | if (const region_svalue *ptr = sval->dyn_cast_region_svalue ()) | |
356 | { | |
357 | const region *reg = ptr->get_pointee (); | |
15e7b93b DM |
358 | const region *base_reg = reg->get_base_region (); |
359 | if (base_reg->get_kind () == RK_DECL | |
360 | || base_reg->get_kind () == RK_STRING) | |
808f4dfe DM |
361 | return m_non_heap; |
362 | } | |
363 | return m_start; | |
364 | } | |
365 | ||
757bf1df DM |
366 | bool on_stmt (sm_context *sm_ctxt, |
367 | const supernode *node, | |
368 | const gimple *stmt) const FINAL OVERRIDE; | |
369 | ||
8525d1f5 DM |
370 | void on_phi (sm_context *sm_ctxt, |
371 | const supernode *node, | |
372 | const gphi *phi, | |
373 | tree rhs) const FINAL OVERRIDE; | |
374 | ||
757bf1df DM |
375 | void on_condition (sm_context *sm_ctxt, |
376 | const supernode *node, | |
377 | const gimple *stmt, | |
48e8a7a6 | 378 | const svalue *lhs, |
757bf1df | 379 | enum tree_code op, |
48e8a7a6 | 380 | const svalue *rhs) const FINAL OVERRIDE; |
757bf1df DM |
381 | |
382 | bool can_purge_p (state_t s) const FINAL OVERRIDE; | |
383 | pending_diagnostic *on_leak (tree var) const FINAL OVERRIDE; | |
384 | ||
808f4dfe DM |
385 | bool reset_when_passed_to_unknown_fn_p (state_t s, |
386 | bool is_mutable) const FINAL OVERRIDE; | |
387 | ||
cd323d97 DM |
388 | static bool unaffected_by_call_p (tree fndecl); |
389 | ||
c7e276b8 DM |
390 | standard_deallocator_set m_free; |
391 | standard_deallocator_set m_scalar_delete; | |
392 | standard_deallocator_set m_vector_delete; | |
1690a839 | 393 | |
a6baafca DM |
394 | standard_deallocator m_realloc; |
395 | ||
1690a839 | 396 | /* States that are independent of api. */ |
757bf1df DM |
397 | |
398 | /* State for a pointer that's known to be NULL. */ | |
399 | state_t m_null; | |
400 | ||
757bf1df DM |
401 | /* State for a pointer that's known to not be on the heap (e.g. to a local |
402 | or global). */ | |
403 | state_t m_non_heap; // TODO: or should this be a different state machine? | |
404 | // or do we need child values etc? | |
405 | ||
406 | /* Stop state, for pointers we don't want to track any more. */ | |
407 | state_t m_stop; | |
8525d1f5 DM |
408 | |
409 | private: | |
c7e276b8 DM |
410 | const custom_deallocator_set * |
411 | get_or_create_custom_deallocator_set (tree allocator_fndecl); | |
412 | custom_deallocator_set * | |
413 | maybe_create_custom_deallocator_set (tree allocator_fndecl); | |
414 | const deallocator * | |
415 | get_or_create_deallocator (tree deallocator_fndecl); | |
416 | ||
1690a839 DM |
417 | void on_allocator_call (sm_context *sm_ctxt, |
418 | const gcall *call, | |
c7e276b8 DM |
419 | const deallocator_set *deallocators, |
420 | bool returns_nonnull = false) const; | |
1690a839 DM |
421 | void on_deallocator_call (sm_context *sm_ctxt, |
422 | const supernode *node, | |
423 | const gcall *call, | |
c7e276b8 DM |
424 | const deallocator *d, |
425 | unsigned argno) const; | |
a6baafca DM |
426 | void on_realloc_call (sm_context *sm_ctxt, |
427 | const supernode *node, | |
428 | const gcall *call) const; | |
8525d1f5 | 429 | void on_zero_assignment (sm_context *sm_ctxt, |
8525d1f5 DM |
430 | const gimple *stmt, |
431 | tree lhs) const; | |
c7e276b8 DM |
432 | |
433 | /* A map for consolidating deallocators so that they are | |
434 | unique per deallocator FUNCTION_DECL. */ | |
435 | typedef hash_map<tree, deallocator *> deallocator_map_t; | |
436 | deallocator_map_t m_deallocator_map; | |
437 | ||
438 | /* Memoized lookups from FUNCTION_DECL to custom_deallocator_set *. */ | |
439 | typedef hash_map<tree, custom_deallocator_set *> deallocator_set_cache_t; | |
440 | deallocator_set_cache_t m_custom_deallocator_set_cache; | |
441 | ||
442 | /* A map for consolidating custom_deallocator_set instances. */ | |
443 | typedef hash_map<custom_deallocator_set::key_t, | |
444 | custom_deallocator_set *, | |
445 | deallocator_set_map_traits> custom_deallocator_set_map_t; | |
446 | custom_deallocator_set_map_t m_custom_deallocator_set_map; | |
447 | ||
448 | /* Record of dynamically-allocated objects, for cleanup. */ | |
449 | auto_vec <custom_deallocator_set *> m_dynamic_sets; | |
450 | auto_vec <custom_deallocator *> m_dynamic_deallocators; | |
757bf1df DM |
451 | }; |
452 | ||
c7e276b8 | 453 | /* struct deallocator. */ |
1690a839 | 454 | |
c7e276b8 DM |
455 | deallocator::deallocator (malloc_state_machine *sm, |
456 | const char *name, | |
457 | enum wording wording) | |
1690a839 | 458 | : m_name (name), |
1690a839 | 459 | m_wording (wording), |
c7e276b8 DM |
460 | m_freed (sm->add_state ("freed", RS_FREED, NULL, this)) |
461 | { | |
462 | } | |
463 | ||
464 | hashval_t | |
465 | deallocator::hash () const | |
466 | { | |
467 | return (hashval_t)m_freed->get_id (); | |
468 | } | |
469 | ||
470 | void | |
471 | deallocator::dump_to_pp (pretty_printer *pp) const | |
472 | { | |
473 | pp_printf (pp, "%qs", m_name); | |
474 | } | |
475 | ||
476 | int | |
477 | deallocator::cmp (const deallocator *a, const deallocator *b) | |
478 | { | |
479 | return (int)a->m_freed->get_id () - (int)b->m_freed->get_id (); | |
480 | } | |
481 | ||
482 | int | |
483 | deallocator::cmp_ptr_ptr (const void *a, const void *b) | |
484 | { | |
485 | return cmp (*(const deallocator * const *)a, | |
486 | *(const deallocator * const *)b); | |
487 | } | |
488 | ||
489 | ||
490 | /* struct standard_deallocator : public deallocator. */ | |
491 | ||
492 | standard_deallocator::standard_deallocator (malloc_state_machine *sm, | |
493 | const char *name, | |
494 | enum wording wording) | |
495 | : deallocator (sm, name, wording) | |
1690a839 DM |
496 | { |
497 | } | |
498 | ||
c7e276b8 DM |
499 | /* struct deallocator_set. */ |
500 | ||
501 | deallocator_set::deallocator_set (malloc_state_machine *sm, | |
502 | enum wording wording) | |
503 | : m_wording (wording), | |
504 | m_unchecked (sm->add_state ("unchecked", RS_UNCHECKED, this, NULL)), | |
505 | m_nonnull (sm->add_state ("nonnull", RS_NONNULL, this, NULL)) | |
506 | { | |
507 | } | |
508 | ||
509 | /* Dump a description of this deallocator_set to stderr. */ | |
510 | ||
511 | DEBUG_FUNCTION void | |
512 | deallocator_set::dump () const | |
513 | { | |
514 | pretty_printer pp; | |
515 | pp_show_color (&pp) = pp_show_color (global_dc->printer); | |
516 | pp.buffer->stream = stderr; | |
517 | dump_to_pp (&pp); | |
518 | pp_newline (&pp); | |
519 | pp_flush (&pp); | |
520 | } | |
521 | ||
522 | /* struct custom_deallocator_set : public deallocator_set. */ | |
523 | ||
524 | custom_deallocator_set:: | |
525 | custom_deallocator_set (malloc_state_machine *sm, | |
526 | const auto_vec <const deallocator *> *vec, | |
527 | enum wording wording) | |
528 | : deallocator_set (sm, wording), | |
529 | m_deallocator_vec (vec->length ()) | |
530 | { | |
531 | unsigned i; | |
532 | const deallocator *d; | |
533 | FOR_EACH_VEC_ELT (*vec, i, d) | |
534 | m_deallocator_vec.safe_push (d); | |
535 | } | |
536 | ||
537 | bool | |
538 | custom_deallocator_set::contains_p (const deallocator *d) const | |
539 | { | |
540 | unsigned i; | |
541 | const deallocator *cd; | |
542 | FOR_EACH_VEC_ELT (m_deallocator_vec, i, cd) | |
543 | if (cd == d) | |
544 | return true; | |
545 | return false; | |
546 | } | |
547 | ||
548 | const deallocator * | |
549 | custom_deallocator_set::maybe_get_single () const | |
550 | { | |
551 | if (m_deallocator_vec.length () == 1) | |
552 | return m_deallocator_vec[0]; | |
553 | return NULL; | |
554 | } | |
555 | ||
556 | void | |
557 | custom_deallocator_set::dump_to_pp (pretty_printer *pp) const | |
558 | { | |
559 | pp_character (pp, '{'); | |
560 | unsigned i; | |
561 | const deallocator *d; | |
562 | FOR_EACH_VEC_ELT (m_deallocator_vec, i, d) | |
563 | { | |
564 | if (i > 0) | |
565 | pp_string (pp, ", "); | |
566 | d->dump_to_pp (pp); | |
567 | } | |
568 | pp_character (pp, '}'); | |
569 | } | |
570 | ||
571 | /* struct standard_deallocator_set : public deallocator_set. */ | |
572 | ||
573 | standard_deallocator_set::standard_deallocator_set (malloc_state_machine *sm, | |
574 | const char *name, | |
575 | enum wording wording) | |
576 | : deallocator_set (sm, wording), | |
577 | m_deallocator (sm, name, wording) | |
578 | { | |
579 | } | |
580 | ||
581 | bool | |
582 | standard_deallocator_set::contains_p (const deallocator *d) const | |
583 | { | |
584 | return d == &m_deallocator; | |
585 | } | |
586 | ||
587 | const deallocator * | |
588 | standard_deallocator_set::maybe_get_single () const | |
589 | { | |
590 | return &m_deallocator; | |
591 | } | |
592 | ||
593 | void | |
594 | standard_deallocator_set::dump_to_pp (pretty_printer *pp) const | |
595 | { | |
596 | pp_character (pp, '{'); | |
597 | pp_string (pp, m_deallocator.m_name); | |
598 | pp_character (pp, '}'); | |
599 | } | |
600 | ||
1690a839 DM |
601 | /* Return STATE cast to the custom state subclass, or NULL for the start state. |
602 | Everything should be an allocation_state apart from the start state. */ | |
603 | ||
604 | static const allocation_state * | |
605 | dyn_cast_allocation_state (state_machine::state_t state) | |
606 | { | |
607 | if (state->get_id () == 0) | |
608 | return NULL; | |
609 | return static_cast <const allocation_state *> (state); | |
610 | } | |
611 | ||
612 | /* Return STATE cast to the custom state subclass, for a state that is | |
613 | already known to not be the start state . */ | |
614 | ||
615 | static const allocation_state * | |
616 | as_a_allocation_state (state_machine::state_t state) | |
617 | { | |
618 | gcc_assert (state->get_id () != 0); | |
619 | return static_cast <const allocation_state *> (state); | |
620 | } | |
621 | ||
622 | /* Get the resource_state for STATE. */ | |
623 | ||
624 | static enum resource_state | |
625 | get_rs (state_machine::state_t state) | |
626 | { | |
627 | if (const allocation_state *astate = dyn_cast_allocation_state (state)) | |
628 | return astate->m_rs; | |
629 | else | |
630 | return RS_START; | |
631 | } | |
632 | ||
c7e276b8 DM |
633 | /* Return true if STATE is the start state. */ |
634 | ||
635 | static bool | |
636 | start_p (state_machine::state_t state) | |
637 | { | |
638 | return get_rs (state) == RS_START; | |
639 | } | |
640 | ||
1690a839 DM |
641 | /* Return true if STATE is an unchecked result from an allocator. */ |
642 | ||
643 | static bool | |
644 | unchecked_p (state_machine::state_t state) | |
645 | { | |
646 | return get_rs (state) == RS_UNCHECKED; | |
647 | } | |
648 | ||
649 | /* Return true if STATE is a non-null result from an allocator. */ | |
650 | ||
651 | static bool | |
652 | nonnull_p (state_machine::state_t state) | |
653 | { | |
654 | return get_rs (state) == RS_NONNULL; | |
655 | } | |
656 | ||
657 | /* Return true if STATE is a value that has been passed to a deallocator. */ | |
658 | ||
659 | static bool | |
660 | freed_p (state_machine::state_t state) | |
661 | { | |
662 | return get_rs (state) == RS_FREED; | |
663 | } | |
664 | ||
757bf1df DM |
665 | /* Class for diagnostics relating to malloc_state_machine. */ |
666 | ||
667 | class malloc_diagnostic : public pending_diagnostic | |
668 | { | |
669 | public: | |
670 | malloc_diagnostic (const malloc_state_machine &sm, tree arg) | |
671 | : m_sm (sm), m_arg (arg) | |
672 | {} | |
673 | ||
674 | bool subclass_equal_p (const pending_diagnostic &base_other) const OVERRIDE | |
675 | { | |
14f9d7b9 | 676 | return same_tree_p (m_arg, ((const malloc_diagnostic &)base_other).m_arg); |
757bf1df DM |
677 | } |
678 | ||
679 | label_text describe_state_change (const evdesc::state_change &change) | |
680 | OVERRIDE | |
681 | { | |
10fc42a8 | 682 | if (change.m_old_state == m_sm.get_start_state () |
1690a839 | 683 | && unchecked_p (change.m_new_state)) |
757bf1df DM |
684 | // TODO: verify that it's the allocation stmt, not a copy |
685 | return label_text::borrow ("allocated here"); | |
1690a839 DM |
686 | if (unchecked_p (change.m_old_state) |
687 | && nonnull_p (change.m_new_state)) | |
808f4dfe DM |
688 | { |
689 | if (change.m_expr) | |
690 | return change.formatted_print ("assuming %qE is non-NULL", | |
691 | change.m_expr); | |
692 | else | |
693 | return change.formatted_print ("assuming %qs is non-NULL", | |
694 | "<unknown>"); | |
695 | } | |
757bf1df | 696 | if (change.m_new_state == m_sm.m_null) |
0993ad65 | 697 | { |
1690a839 | 698 | if (unchecked_p (change.m_old_state)) |
808f4dfe DM |
699 | { |
700 | if (change.m_expr) | |
701 | return change.formatted_print ("assuming %qE is NULL", | |
702 | change.m_expr); | |
703 | else | |
704 | return change.formatted_print ("assuming %qs is NULL", | |
705 | "<unknown>"); | |
706 | } | |
0993ad65 | 707 | else |
808f4dfe DM |
708 | { |
709 | if (change.m_expr) | |
710 | return change.formatted_print ("%qE is NULL", | |
711 | change.m_expr); | |
712 | else | |
713 | return change.formatted_print ("%qs is NULL", | |
714 | "<unknown>"); | |
715 | } | |
0993ad65 DM |
716 | } |
717 | ||
757bf1df DM |
718 | return label_text (); |
719 | } | |
720 | ||
721 | protected: | |
722 | const malloc_state_machine &m_sm; | |
723 | tree m_arg; | |
724 | }; | |
725 | ||
1690a839 DM |
726 | /* Concrete subclass for reporting mismatching allocator/deallocator |
727 | diagnostics. */ | |
728 | ||
729 | class mismatching_deallocation : public malloc_diagnostic | |
730 | { | |
731 | public: | |
732 | mismatching_deallocation (const malloc_state_machine &sm, tree arg, | |
c7e276b8 DM |
733 | const deallocator_set *expected_deallocators, |
734 | const deallocator *actual_dealloc) | |
1690a839 | 735 | : malloc_diagnostic (sm, arg), |
c7e276b8 | 736 | m_expected_deallocators (expected_deallocators), |
1690a839 DM |
737 | m_actual_dealloc (actual_dealloc) |
738 | {} | |
739 | ||
740 | const char *get_kind () const FINAL OVERRIDE | |
741 | { | |
742 | return "mismatching_deallocation"; | |
743 | } | |
744 | ||
745 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
746 | { | |
747 | auto_diagnostic_group d; | |
748 | diagnostic_metadata m; | |
749 | m.add_cwe (762); /* CWE-762: Mismatched Memory Management Routines. */ | |
c7e276b8 DM |
750 | if (const deallocator *expected_dealloc |
751 | = m_expected_deallocators->maybe_get_single ()) | |
752 | return warning_meta (rich_loc, m, OPT_Wanalyzer_mismatching_deallocation, | |
753 | "%qE should have been deallocated with %qs" | |
754 | " but was deallocated with %qs", | |
755 | m_arg, expected_dealloc->m_name, | |
756 | m_actual_dealloc->m_name); | |
757 | else | |
758 | return warning_meta (rich_loc, m, OPT_Wanalyzer_mismatching_deallocation, | |
759 | "%qs called on %qE returned from a mismatched" | |
760 | " allocation function", | |
761 | m_actual_dealloc->m_name, m_arg); | |
1690a839 DM |
762 | } |
763 | ||
764 | label_text describe_state_change (const evdesc::state_change &change) | |
765 | FINAL OVERRIDE | |
766 | { | |
767 | if (unchecked_p (change.m_new_state)) | |
768 | { | |
769 | m_alloc_event = change.m_event_id; | |
c7e276b8 DM |
770 | if (const deallocator *expected_dealloc |
771 | = m_expected_deallocators->maybe_get_single ()) | |
772 | return change.formatted_print ("allocated here" | |
773 | " (expects deallocation with %qs)", | |
774 | expected_dealloc->m_name); | |
775 | else | |
776 | return change.formatted_print ("allocated here"); | |
1690a839 DM |
777 | } |
778 | return malloc_diagnostic::describe_state_change (change); | |
779 | } | |
780 | ||
781 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
782 | { | |
783 | if (m_alloc_event.known_p ()) | |
c7e276b8 DM |
784 | { |
785 | if (const deallocator *expected_dealloc | |
786 | = m_expected_deallocators->maybe_get_single ()) | |
787 | return ev.formatted_print | |
788 | ("deallocated with %qs here;" | |
789 | " allocation at %@ expects deallocation with %qs", | |
790 | m_actual_dealloc->m_name, &m_alloc_event, | |
791 | expected_dealloc->m_name); | |
792 | else | |
793 | return ev.formatted_print | |
794 | ("deallocated with %qs here;" | |
795 | " allocated at %@", | |
796 | m_actual_dealloc->m_name, &m_alloc_event); | |
797 | } | |
1690a839 | 798 | return ev.formatted_print ("deallocated with %qs here", |
c7e276b8 | 799 | m_actual_dealloc->m_name); |
1690a839 DM |
800 | } |
801 | ||
802 | private: | |
803 | diagnostic_event_id_t m_alloc_event; | |
c7e276b8 DM |
804 | const deallocator_set *m_expected_deallocators; |
805 | const deallocator *m_actual_dealloc; | |
1690a839 DM |
806 | }; |
807 | ||
757bf1df DM |
808 | /* Concrete subclass for reporting double-free diagnostics. */ |
809 | ||
810 | class double_free : public malloc_diagnostic | |
811 | { | |
812 | public: | |
1690a839 DM |
813 | double_free (const malloc_state_machine &sm, tree arg, const char *funcname) |
814 | : malloc_diagnostic (sm, arg), m_funcname (funcname) | |
757bf1df DM |
815 | {} |
816 | ||
817 | const char *get_kind () const FINAL OVERRIDE { return "double_free"; } | |
818 | ||
819 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
820 | { | |
821 | auto_diagnostic_group d; | |
822 | diagnostic_metadata m; | |
823 | m.add_cwe (415); /* CWE-415: Double Free. */ | |
6c8e5844 | 824 | return warning_meta (rich_loc, m, OPT_Wanalyzer_double_free, |
c7e276b8 | 825 | "double-%qs of %qE", m_funcname, m_arg); |
757bf1df DM |
826 | } |
827 | ||
828 | label_text describe_state_change (const evdesc::state_change &change) | |
829 | FINAL OVERRIDE | |
830 | { | |
1690a839 | 831 | if (freed_p (change.m_new_state)) |
757bf1df DM |
832 | { |
833 | m_first_free_event = change.m_event_id; | |
1690a839 | 834 | return change.formatted_print ("first %qs here", m_funcname); |
757bf1df DM |
835 | } |
836 | return malloc_diagnostic::describe_state_change (change); | |
837 | } | |
838 | ||
839 | label_text describe_call_with_state (const evdesc::call_with_state &info) | |
840 | FINAL OVERRIDE | |
841 | { | |
1690a839 | 842 | if (freed_p (info.m_state)) |
757bf1df DM |
843 | return info.formatted_print |
844 | ("passing freed pointer %qE in call to %qE from %qE", | |
845 | info.m_expr, info.m_callee_fndecl, info.m_caller_fndecl); | |
846 | return label_text (); | |
847 | } | |
848 | ||
849 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
850 | { | |
851 | if (m_first_free_event.known_p ()) | |
852 | return ev.formatted_print ("second %qs here; first %qs was at %@", | |
1690a839 | 853 | m_funcname, m_funcname, |
757bf1df | 854 | &m_first_free_event); |
1690a839 | 855 | return ev.formatted_print ("second %qs here", m_funcname); |
757bf1df DM |
856 | } |
857 | ||
858 | private: | |
859 | diagnostic_event_id_t m_first_free_event; | |
1690a839 | 860 | const char *m_funcname; |
757bf1df DM |
861 | }; |
862 | ||
863 | /* Abstract subclass for describing possible bad uses of NULL. | |
864 | Responsible for describing the call that could return NULL. */ | |
865 | ||
866 | class possible_null : public malloc_diagnostic | |
867 | { | |
868 | public: | |
869 | possible_null (const malloc_state_machine &sm, tree arg) | |
870 | : malloc_diagnostic (sm, arg) | |
871 | {} | |
872 | ||
873 | label_text describe_state_change (const evdesc::state_change &change) | |
874 | FINAL OVERRIDE | |
875 | { | |
10fc42a8 | 876 | if (change.m_old_state == m_sm.get_start_state () |
1690a839 | 877 | && unchecked_p (change.m_new_state)) |
757bf1df DM |
878 | { |
879 | m_origin_of_unchecked_event = change.m_event_id; | |
880 | return label_text::borrow ("this call could return NULL"); | |
881 | } | |
882 | return malloc_diagnostic::describe_state_change (change); | |
883 | } | |
884 | ||
885 | label_text describe_return_of_state (const evdesc::return_of_state &info) | |
886 | FINAL OVERRIDE | |
887 | { | |
1690a839 | 888 | if (unchecked_p (info.m_state)) |
757bf1df DM |
889 | return info.formatted_print ("possible return of NULL to %qE from %qE", |
890 | info.m_caller_fndecl, info.m_callee_fndecl); | |
891 | return label_text (); | |
892 | } | |
893 | ||
894 | protected: | |
895 | diagnostic_event_id_t m_origin_of_unchecked_event; | |
896 | }; | |
897 | ||
898 | /* Concrete subclass for describing dereference of a possible NULL | |
899 | value. */ | |
900 | ||
901 | class possible_null_deref : public possible_null | |
902 | { | |
903 | public: | |
904 | possible_null_deref (const malloc_state_machine &sm, tree arg) | |
905 | : possible_null (sm, arg) | |
906 | {} | |
907 | ||
908 | const char *get_kind () const FINAL OVERRIDE { return "possible_null_deref"; } | |
909 | ||
910 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
911 | { | |
912 | /* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */ | |
913 | diagnostic_metadata m; | |
914 | m.add_cwe (690); | |
6c8e5844 DM |
915 | return warning_meta (rich_loc, m, |
916 | OPT_Wanalyzer_possible_null_dereference, | |
917 | "dereference of possibly-NULL %qE", m_arg); | |
757bf1df DM |
918 | } |
919 | ||
920 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
921 | { | |
922 | if (m_origin_of_unchecked_event.known_p ()) | |
923 | return ev.formatted_print ("%qE could be NULL: unchecked value from %@", | |
924 | ev.m_expr, | |
925 | &m_origin_of_unchecked_event); | |
926 | else | |
927 | return ev.formatted_print ("%qE could be NULL", ev.m_expr); | |
928 | } | |
929 | ||
930 | }; | |
931 | ||
2f7c50b7 DM |
932 | /* Return true if FNDECL is a C++ method. */ |
933 | ||
934 | static bool | |
935 | method_p (tree fndecl) | |
936 | { | |
937 | return TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE; | |
938 | } | |
939 | ||
940 | /* Return a 1-based description of ARG_IDX (0-based) of FNDECL. | |
941 | Compare with %P in the C++ FE (implemented in cp/error.c: parm_to_string | |
942 | as called from cp_printer). */ | |
943 | ||
944 | static label_text | |
945 | describe_argument_index (tree fndecl, int arg_idx) | |
946 | { | |
947 | if (method_p (fndecl)) | |
948 | if (arg_idx == 0) | |
949 | return label_text::borrow ("'this'"); | |
950 | pretty_printer pp; | |
951 | pp_printf (&pp, "%u", arg_idx + 1 - method_p (fndecl)); | |
952 | return label_text::take (xstrdup (pp_formatted_text (&pp))); | |
953 | } | |
954 | ||
757bf1df DM |
955 | /* Subroutine for use by possible_null_arg::emit and null_arg::emit. |
956 | Issue a note informing that the pertinent argument must be non-NULL. */ | |
957 | ||
958 | static void | |
959 | inform_nonnull_attribute (tree fndecl, int arg_idx) | |
960 | { | |
2f7c50b7 | 961 | label_text arg_desc = describe_argument_index (fndecl, arg_idx); |
757bf1df | 962 | inform (DECL_SOURCE_LOCATION (fndecl), |
2f7c50b7 DM |
963 | "argument %s of %qD must be non-null", |
964 | arg_desc.m_buffer, fndecl); | |
965 | arg_desc.maybe_free (); | |
757bf1df DM |
966 | /* Ideally we would use the location of the parm and underline the |
967 | attribute also - but we don't have the location_t values at this point | |
968 | in the middle-end. | |
969 | For reference, the C and C++ FEs have get_fndecl_argument_location. */ | |
970 | } | |
971 | ||
972 | /* Concrete subclass for describing passing a possibly-NULL value to a | |
973 | function marked with __attribute__((nonnull)). */ | |
974 | ||
975 | class possible_null_arg : public possible_null | |
976 | { | |
977 | public: | |
978 | possible_null_arg (const malloc_state_machine &sm, tree arg, | |
979 | tree fndecl, int arg_idx) | |
980 | : possible_null (sm, arg), | |
981 | m_fndecl (fndecl), m_arg_idx (arg_idx) | |
982 | {} | |
983 | ||
984 | const char *get_kind () const FINAL OVERRIDE { return "possible_null_arg"; } | |
985 | ||
986 | bool subclass_equal_p (const pending_diagnostic &base_other) const | |
987 | { | |
988 | const possible_null_arg &sub_other | |
989 | = (const possible_null_arg &)base_other; | |
14f9d7b9 | 990 | return (same_tree_p (m_arg, sub_other.m_arg) |
757bf1df DM |
991 | && m_fndecl == sub_other.m_fndecl |
992 | && m_arg_idx == sub_other.m_arg_idx); | |
993 | } | |
994 | ||
995 | ||
996 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
997 | { | |
998 | /* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */ | |
999 | auto_diagnostic_group d; | |
1000 | diagnostic_metadata m; | |
1001 | m.add_cwe (690); | |
1002 | bool warned | |
6c8e5844 DM |
1003 | = warning_meta (rich_loc, m, OPT_Wanalyzer_possible_null_argument, |
1004 | "use of possibly-NULL %qE where non-null expected", | |
1005 | m_arg); | |
757bf1df DM |
1006 | if (warned) |
1007 | inform_nonnull_attribute (m_fndecl, m_arg_idx); | |
1008 | return warned; | |
1009 | } | |
1010 | ||
1011 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1012 | { | |
2f7c50b7 DM |
1013 | label_text arg_desc = describe_argument_index (m_fndecl, m_arg_idx); |
1014 | label_text result; | |
757bf1df | 1015 | if (m_origin_of_unchecked_event.known_p ()) |
2f7c50b7 DM |
1016 | result = ev.formatted_print ("argument %s (%qE) from %@ could be NULL" |
1017 | " where non-null expected", | |
1018 | arg_desc.m_buffer, ev.m_expr, | |
1019 | &m_origin_of_unchecked_event); | |
757bf1df | 1020 | else |
2f7c50b7 DM |
1021 | result = ev.formatted_print ("argument %s (%qE) could be NULL" |
1022 | " where non-null expected", | |
1023 | arg_desc.m_buffer, ev.m_expr); | |
1024 | arg_desc.maybe_free (); | |
1025 | return result; | |
757bf1df DM |
1026 | } |
1027 | ||
1028 | private: | |
1029 | tree m_fndecl; | |
1030 | int m_arg_idx; | |
1031 | }; | |
1032 | ||
1033 | /* Concrete subclass for describing a dereference of a NULL value. */ | |
1034 | ||
1035 | class null_deref : public malloc_diagnostic | |
1036 | { | |
1037 | public: | |
1038 | null_deref (const malloc_state_machine &sm, tree arg) | |
1039 | : malloc_diagnostic (sm, arg) {} | |
1040 | ||
1041 | const char *get_kind () const FINAL OVERRIDE { return "null_deref"; } | |
1042 | ||
1043 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
1044 | { | |
f3f312b5 | 1045 | /* CWE-476: NULL Pointer Dereference. */ |
757bf1df | 1046 | diagnostic_metadata m; |
f3f312b5 | 1047 | m.add_cwe (476); |
6c8e5844 DM |
1048 | return warning_meta (rich_loc, m, |
1049 | OPT_Wanalyzer_null_dereference, | |
1050 | "dereference of NULL %qE", m_arg); | |
757bf1df DM |
1051 | } |
1052 | ||
1053 | label_text describe_return_of_state (const evdesc::return_of_state &info) | |
1054 | FINAL OVERRIDE | |
1055 | { | |
1056 | if (info.m_state == m_sm.m_null) | |
1057 | return info.formatted_print ("return of NULL to %qE from %qE", | |
1058 | info.m_caller_fndecl, info.m_callee_fndecl); | |
1059 | return label_text (); | |
1060 | } | |
1061 | ||
1062 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1063 | { | |
1064 | return ev.formatted_print ("dereference of NULL %qE", ev.m_expr); | |
1065 | } | |
1066 | }; | |
1067 | ||
1068 | /* Concrete subclass for describing passing a NULL value to a | |
1069 | function marked with __attribute__((nonnull)). */ | |
1070 | ||
1071 | class null_arg : public malloc_diagnostic | |
1072 | { | |
1073 | public: | |
1074 | null_arg (const malloc_state_machine &sm, tree arg, | |
1075 | tree fndecl, int arg_idx) | |
1076 | : malloc_diagnostic (sm, arg), | |
1077 | m_fndecl (fndecl), m_arg_idx (arg_idx) | |
1078 | {} | |
1079 | ||
1080 | const char *get_kind () const FINAL OVERRIDE { return "null_arg"; } | |
1081 | ||
1082 | bool subclass_equal_p (const pending_diagnostic &base_other) const | |
1083 | { | |
1084 | const null_arg &sub_other | |
1085 | = (const null_arg &)base_other; | |
14f9d7b9 | 1086 | return (same_tree_p (m_arg, sub_other.m_arg) |
757bf1df DM |
1087 | && m_fndecl == sub_other.m_fndecl |
1088 | && m_arg_idx == sub_other.m_arg_idx); | |
1089 | } | |
1090 | ||
1091 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
1092 | { | |
f3f312b5 | 1093 | /* CWE-476: NULL Pointer Dereference. */ |
757bf1df DM |
1094 | auto_diagnostic_group d; |
1095 | diagnostic_metadata m; | |
f3f312b5 | 1096 | m.add_cwe (476); |
808f4dfe DM |
1097 | |
1098 | bool warned; | |
1099 | if (zerop (m_arg)) | |
1100 | warned = warning_meta (rich_loc, m, OPT_Wanalyzer_null_argument, | |
1101 | "use of NULL where non-null expected"); | |
1102 | else | |
1103 | warned = warning_meta (rich_loc, m, OPT_Wanalyzer_null_argument, | |
1104 | "use of NULL %qE where non-null expected", | |
1105 | m_arg); | |
757bf1df DM |
1106 | if (warned) |
1107 | inform_nonnull_attribute (m_fndecl, m_arg_idx); | |
1108 | return warned; | |
1109 | } | |
1110 | ||
1111 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1112 | { | |
2f7c50b7 DM |
1113 | label_text arg_desc = describe_argument_index (m_fndecl, m_arg_idx); |
1114 | label_text result; | |
808f4dfe | 1115 | if (zerop (ev.m_expr)) |
2f7c50b7 DM |
1116 | result = ev.formatted_print ("argument %s NULL where non-null expected", |
1117 | arg_desc.m_buffer); | |
808f4dfe | 1118 | else |
2f7c50b7 DM |
1119 | result = ev.formatted_print ("argument %s (%qE) NULL" |
1120 | " where non-null expected", | |
1121 | arg_desc.m_buffer, ev.m_expr); | |
1122 | arg_desc.maybe_free (); | |
1123 | return result; | |
757bf1df DM |
1124 | } |
1125 | ||
1126 | private: | |
1127 | tree m_fndecl; | |
1128 | int m_arg_idx; | |
1129 | }; | |
1130 | ||
1131 | class use_after_free : public malloc_diagnostic | |
1132 | { | |
1133 | public: | |
1690a839 | 1134 | use_after_free (const malloc_state_machine &sm, tree arg, |
c7e276b8 DM |
1135 | const deallocator *deallocator) |
1136 | : malloc_diagnostic (sm, arg), | |
1137 | m_deallocator (deallocator) | |
1138 | { | |
1139 | gcc_assert (deallocator); | |
1140 | } | |
757bf1df DM |
1141 | |
1142 | const char *get_kind () const FINAL OVERRIDE { return "use_after_free"; } | |
1143 | ||
1144 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
1145 | { | |
1146 | /* CWE-416: Use After Free. */ | |
1147 | diagnostic_metadata m; | |
1148 | m.add_cwe (416); | |
6c8e5844 | 1149 | return warning_meta (rich_loc, m, OPT_Wanalyzer_use_after_free, |
1690a839 | 1150 | "use after %<%s%> of %qE", |
c7e276b8 | 1151 | m_deallocator->m_name, m_arg); |
757bf1df DM |
1152 | } |
1153 | ||
1154 | label_text describe_state_change (const evdesc::state_change &change) | |
1155 | FINAL OVERRIDE | |
1156 | { | |
1690a839 | 1157 | if (freed_p (change.m_new_state)) |
757bf1df DM |
1158 | { |
1159 | m_free_event = change.m_event_id; | |
c7e276b8 | 1160 | switch (m_deallocator->m_wording) |
1690a839 DM |
1161 | { |
1162 | default: | |
a6baafca | 1163 | case WORDING_REALLOCATED: |
1690a839 DM |
1164 | gcc_unreachable (); |
1165 | case WORDING_FREED: | |
1166 | return label_text::borrow ("freed here"); | |
1167 | case WORDING_DELETED: | |
1168 | return label_text::borrow ("deleted here"); | |
c7e276b8 DM |
1169 | case WORDING_DEALLOCATED: |
1170 | return label_text::borrow ("deallocated here"); | |
1690a839 | 1171 | } |
757bf1df DM |
1172 | } |
1173 | return malloc_diagnostic::describe_state_change (change); | |
1174 | } | |
1175 | ||
1176 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1177 | { | |
c7e276b8 | 1178 | const char *funcname = m_deallocator->m_name; |
757bf1df | 1179 | if (m_free_event.known_p ()) |
c7e276b8 | 1180 | switch (m_deallocator->m_wording) |
1690a839 DM |
1181 | { |
1182 | default: | |
a6baafca | 1183 | case WORDING_REALLOCATED: |
1690a839 DM |
1184 | gcc_unreachable (); |
1185 | case WORDING_FREED: | |
1186 | return ev.formatted_print ("use after %<%s%> of %qE; freed at %@", | |
1187 | funcname, ev.m_expr, &m_free_event); | |
1188 | case WORDING_DELETED: | |
1189 | return ev.formatted_print ("use after %<%s%> of %qE; deleted at %@", | |
1190 | funcname, ev.m_expr, &m_free_event); | |
c7e276b8 DM |
1191 | case WORDING_DEALLOCATED: |
1192 | return ev.formatted_print ("use after %<%s%> of %qE;" | |
1193 | " deallocated at %@", | |
1194 | funcname, ev.m_expr, &m_free_event); | |
1690a839 | 1195 | } |
757bf1df | 1196 | else |
1690a839 DM |
1197 | return ev.formatted_print ("use after %<%s%> of %qE", |
1198 | funcname, ev.m_expr); | |
757bf1df DM |
1199 | } |
1200 | ||
33255ad3 DM |
1201 | /* Implementation of pending_diagnostic::supercedes_p for |
1202 | use_after_free. | |
1203 | ||
1204 | We want use-after-free to supercede use-of-unitialized-value, | |
1205 | so that if we have these at the same stmt, we don't emit | |
1206 | a use-of-uninitialized, just the use-after-free. | |
1207 | (this is because we fully purge information about freed | |
1208 | buffers when we free them to avoid state explosions, so | |
1209 | that if they are accessed after the free, it looks like | |
1210 | they are uninitialized). */ | |
1211 | ||
1212 | bool supercedes_p (const pending_diagnostic &other) const FINAL OVERRIDE | |
1213 | { | |
1214 | if (other.use_of_uninit_p ()) | |
1215 | return true; | |
1216 | ||
1217 | return false; | |
1218 | } | |
1219 | ||
757bf1df DM |
1220 | private: |
1221 | diagnostic_event_id_t m_free_event; | |
c7e276b8 | 1222 | const deallocator *m_deallocator; |
757bf1df DM |
1223 | }; |
1224 | ||
1225 | class malloc_leak : public malloc_diagnostic | |
1226 | { | |
1227 | public: | |
1228 | malloc_leak (const malloc_state_machine &sm, tree arg) | |
1229 | : malloc_diagnostic (sm, arg) {} | |
1230 | ||
1231 | const char *get_kind () const FINAL OVERRIDE { return "malloc_leak"; } | |
1232 | ||
1233 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
1234 | { | |
1235 | diagnostic_metadata m; | |
1236 | m.add_cwe (401); | |
808f4dfe DM |
1237 | if (m_arg) |
1238 | return warning_meta (rich_loc, m, OPT_Wanalyzer_malloc_leak, | |
1239 | "leak of %qE", m_arg); | |
1240 | else | |
1241 | return warning_meta (rich_loc, m, OPT_Wanalyzer_malloc_leak, | |
1242 | "leak of %qs", "<unknown>"); | |
757bf1df DM |
1243 | } |
1244 | ||
1245 | label_text describe_state_change (const evdesc::state_change &change) | |
1246 | FINAL OVERRIDE | |
1247 | { | |
c7e276b8 DM |
1248 | if (unchecked_p (change.m_new_state) |
1249 | || (start_p (change.m_old_state) && nonnull_p (change.m_new_state))) | |
757bf1df | 1250 | { |
1690a839 | 1251 | m_alloc_event = change.m_event_id; |
757bf1df DM |
1252 | return label_text::borrow ("allocated here"); |
1253 | } | |
1254 | return malloc_diagnostic::describe_state_change (change); | |
1255 | } | |
1256 | ||
1257 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1258 | { | |
808f4dfe DM |
1259 | if (ev.m_expr) |
1260 | { | |
1690a839 | 1261 | if (m_alloc_event.known_p ()) |
808f4dfe | 1262 | return ev.formatted_print ("%qE leaks here; was allocated at %@", |
1690a839 | 1263 | ev.m_expr, &m_alloc_event); |
808f4dfe DM |
1264 | else |
1265 | return ev.formatted_print ("%qE leaks here", ev.m_expr); | |
1266 | } | |
757bf1df | 1267 | else |
808f4dfe | 1268 | { |
1690a839 | 1269 | if (m_alloc_event.known_p ()) |
808f4dfe | 1270 | return ev.formatted_print ("%qs leaks here; was allocated at %@", |
1690a839 | 1271 | "<unknown>", &m_alloc_event); |
808f4dfe DM |
1272 | else |
1273 | return ev.formatted_print ("%qs leaks here", "<unknown>"); | |
1274 | } | |
757bf1df DM |
1275 | } |
1276 | ||
1277 | private: | |
1690a839 | 1278 | diagnostic_event_id_t m_alloc_event; |
757bf1df DM |
1279 | }; |
1280 | ||
1281 | class free_of_non_heap : public malloc_diagnostic | |
1282 | { | |
1283 | public: | |
1690a839 DM |
1284 | free_of_non_heap (const malloc_state_machine &sm, tree arg, |
1285 | const char *funcname) | |
1286 | : malloc_diagnostic (sm, arg), m_funcname (funcname), m_kind (KIND_UNKNOWN) | |
757bf1df DM |
1287 | { |
1288 | } | |
1289 | ||
1290 | const char *get_kind () const FINAL OVERRIDE { return "free_of_non_heap"; } | |
1291 | ||
1292 | bool subclass_equal_p (const pending_diagnostic &base_other) const | |
1293 | FINAL OVERRIDE | |
1294 | { | |
1295 | const free_of_non_heap &other = (const free_of_non_heap &)base_other; | |
14f9d7b9 | 1296 | return (same_tree_p (m_arg, other.m_arg) && m_kind == other.m_kind); |
757bf1df DM |
1297 | } |
1298 | ||
1299 | bool emit (rich_location *rich_loc) FINAL OVERRIDE | |
1300 | { | |
1301 | auto_diagnostic_group d; | |
1302 | diagnostic_metadata m; | |
1303 | m.add_cwe (590); /* CWE-590: Free of Memory not on the Heap. */ | |
1304 | switch (m_kind) | |
1305 | { | |
1306 | default: | |
1307 | gcc_unreachable (); | |
1308 | case KIND_UNKNOWN: | |
6c8e5844 | 1309 | return warning_meta (rich_loc, m, OPT_Wanalyzer_free_of_non_heap, |
1690a839 | 1310 | "%<%s%> of %qE which points to memory" |
6c8e5844 | 1311 | " not on the heap", |
1690a839 | 1312 | m_funcname, m_arg); |
757bf1df DM |
1313 | break; |
1314 | case KIND_ALLOCA: | |
6c8e5844 | 1315 | return warning_meta (rich_loc, m, OPT_Wanalyzer_free_of_non_heap, |
1690a839 | 1316 | "%<%s%> of memory allocated on the stack by" |
6c8e5844 | 1317 | " %qs (%qE) will corrupt the heap", |
1690a839 | 1318 | m_funcname, "alloca", m_arg); |
757bf1df DM |
1319 | break; |
1320 | } | |
1321 | } | |
1322 | ||
1323 | label_text describe_state_change (const evdesc::state_change &change) | |
1324 | FINAL OVERRIDE | |
1325 | { | |
1326 | /* Attempt to reconstruct what kind of pointer it is. | |
1327 | (It seems neater for this to be a part of the state, though). */ | |
61bfff56 | 1328 | if (change.m_expr && TREE_CODE (change.m_expr) == SSA_NAME) |
757bf1df DM |
1329 | { |
1330 | gimple *def_stmt = SSA_NAME_DEF_STMT (change.m_expr); | |
1331 | if (gcall *call = dyn_cast <gcall *> (def_stmt)) | |
1332 | { | |
1333 | if (is_special_named_call_p (call, "alloca", 1) | |
1334 | || is_special_named_call_p (call, "__builtin_alloca", 1)) | |
1335 | { | |
1336 | m_kind = KIND_ALLOCA; | |
1337 | return label_text::borrow | |
1338 | ("memory is allocated on the stack here"); | |
1339 | } | |
1340 | } | |
1341 | } | |
1342 | return label_text::borrow ("pointer is from here"); | |
1343 | } | |
1344 | ||
1345 | label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE | |
1346 | { | |
1690a839 | 1347 | return ev.formatted_print ("call to %qs here", m_funcname); |
757bf1df DM |
1348 | } |
1349 | ||
1350 | private: | |
1351 | enum kind | |
1352 | { | |
1353 | KIND_UNKNOWN, | |
1354 | KIND_ALLOCA | |
1355 | }; | |
1690a839 | 1356 | const char *m_funcname; |
757bf1df DM |
1357 | enum kind m_kind; |
1358 | }; | |
1359 | ||
1690a839 DM |
1360 | /* struct allocation_state : public state_machine::state. */ |
1361 | ||
1362 | /* Implementation of state_machine::state::dump_to_pp vfunc | |
1363 | for allocation_state: append the API that this allocation is | |
1364 | associated with. */ | |
1365 | ||
1366 | void | |
1367 | allocation_state::dump_to_pp (pretty_printer *pp) const | |
1368 | { | |
1369 | state_machine::state::dump_to_pp (pp); | |
c7e276b8 DM |
1370 | if (m_deallocators) |
1371 | { | |
1372 | pp_string (pp, " ("); | |
1373 | m_deallocators->dump_to_pp (pp); | |
1374 | pp_character (pp, ')'); | |
1375 | } | |
1690a839 DM |
1376 | } |
1377 | ||
c7e276b8 DM |
1378 | /* Given a allocation_state for a deallocator_set, get the "nonnull" state |
1379 | for the corresponding allocator(s). */ | |
1690a839 DM |
1380 | |
1381 | const allocation_state * | |
1382 | allocation_state::get_nonnull () const | |
1383 | { | |
c7e276b8 DM |
1384 | gcc_assert (m_deallocators); |
1385 | return as_a_allocation_state (m_deallocators->m_nonnull); | |
1690a839 DM |
1386 | } |
1387 | ||
757bf1df DM |
1388 | /* malloc_state_machine's ctor. */ |
1389 | ||
1390 | malloc_state_machine::malloc_state_machine (logger *logger) | |
1690a839 | 1391 | : state_machine ("malloc", logger), |
c7e276b8 DM |
1392 | m_free (this, "free", WORDING_FREED), |
1393 | m_scalar_delete (this, "delete", WORDING_DELETED), | |
a6baafca DM |
1394 | m_vector_delete (this, "delete[]", WORDING_DELETED), |
1395 | m_realloc (this, "realloc", WORDING_REALLOCATED) | |
1690a839 DM |
1396 | { |
1397 | gcc_assert (m_start->get_id () == 0); | |
c7e276b8 DM |
1398 | m_null = add_state ("null", RS_FREED, NULL, NULL); |
1399 | m_non_heap = add_state ("non-heap", RS_NON_HEAP, NULL, NULL); | |
1400 | m_stop = add_state ("stop", RS_STOP, NULL, NULL); | |
1401 | } | |
1402 | ||
1403 | malloc_state_machine::~malloc_state_machine () | |
1404 | { | |
1405 | unsigned i; | |
1406 | custom_deallocator_set *set; | |
1407 | FOR_EACH_VEC_ELT (m_dynamic_sets, i, set) | |
1408 | delete set; | |
1409 | custom_deallocator *d; | |
1410 | FOR_EACH_VEC_ELT (m_dynamic_deallocators, i, d) | |
1411 | delete d; | |
1690a839 DM |
1412 | } |
1413 | ||
1414 | state_machine::state_t | |
1415 | malloc_state_machine::add_state (const char *name, enum resource_state rs, | |
c7e276b8 DM |
1416 | const deallocator_set *deallocators, |
1417 | const deallocator *deallocator) | |
1690a839 DM |
1418 | { |
1419 | return add_custom_state (new allocation_state (name, alloc_state_id (), | |
c7e276b8 DM |
1420 | rs, deallocators, |
1421 | deallocator)); | |
1422 | } | |
1423 | ||
1424 | /* If ALLOCATOR_FNDECL has any "__attribute__((malloc(FOO)))", | |
1425 | return a custom_deallocator_set for them, consolidating them | |
1426 | to ensure uniqueness of the sets. | |
1427 | ||
1428 | Return NULL if it has no such attributes. */ | |
1429 | ||
1430 | const custom_deallocator_set * | |
1431 | malloc_state_machine:: | |
1432 | get_or_create_custom_deallocator_set (tree allocator_fndecl) | |
1433 | { | |
1434 | /* Early rejection of decls without attributes. */ | |
1435 | tree attrs = DECL_ATTRIBUTES (allocator_fndecl); | |
1436 | if (!attrs) | |
1437 | return NULL; | |
1438 | ||
1439 | /* Otherwise, call maybe_create_custom_deallocator_set, | |
1440 | memoizing the result. */ | |
1441 | if (custom_deallocator_set **slot | |
1442 | = m_custom_deallocator_set_cache.get (allocator_fndecl)) | |
1443 | return *slot; | |
1444 | custom_deallocator_set *set | |
1445 | = maybe_create_custom_deallocator_set (allocator_fndecl); | |
1446 | m_custom_deallocator_set_cache.put (allocator_fndecl, set); | |
1447 | return set; | |
1448 | } | |
1449 | ||
1450 | /* Given ALLOCATOR_FNDECL, a FUNCTION_DECL with attributes, | |
1451 | look for any "__attribute__((malloc(FOO)))" and return a | |
1452 | custom_deallocator_set for them, consolidating them | |
1453 | to ensure uniqueness of the sets. | |
1454 | ||
1455 | Return NULL if it has no such attributes. | |
1456 | ||
1457 | Subroutine of get_or_create_custom_deallocator_set which | |
1458 | memoizes the result. */ | |
1459 | ||
1460 | custom_deallocator_set * | |
1461 | malloc_state_machine:: | |
1462 | maybe_create_custom_deallocator_set (tree allocator_fndecl) | |
1463 | { | |
1464 | tree attrs = DECL_ATTRIBUTES (allocator_fndecl); | |
1465 | gcc_assert (attrs); | |
1466 | ||
1467 | /* Look for instances of __attribute__((malloc(FOO))). */ | |
1468 | auto_vec<const deallocator *> deallocator_vec; | |
1469 | for (tree allocs = attrs; | |
1470 | (allocs = lookup_attribute ("malloc", allocs)); | |
1471 | allocs = TREE_CHAIN (allocs)) | |
1472 | { | |
1473 | tree args = TREE_VALUE (allocs); | |
1474 | if (!args) | |
1475 | continue; | |
1476 | if (TREE_VALUE (args)) | |
1477 | { | |
1478 | const deallocator *d | |
1479 | = get_or_create_deallocator (TREE_VALUE (args)); | |
1480 | deallocator_vec.safe_push (d); | |
1481 | } | |
1482 | } | |
1483 | ||
1484 | /* If there weren't any deallocators, bail. */ | |
1485 | if (deallocator_vec.length () == 0) | |
1486 | return NULL; | |
1487 | ||
1488 | /* Consolidate, so that we reuse existing deallocator_set | |
1489 | instances. */ | |
1490 | deallocator_vec.qsort (deallocator::cmp_ptr_ptr); | |
1491 | custom_deallocator_set **slot | |
1492 | = m_custom_deallocator_set_map.get (&deallocator_vec); | |
1493 | if (slot) | |
1494 | return *slot; | |
1495 | custom_deallocator_set *set | |
1496 | = new custom_deallocator_set (this, &deallocator_vec, WORDING_DEALLOCATED); | |
1497 | m_custom_deallocator_set_map.put (&set->m_deallocator_vec, set); | |
1498 | m_dynamic_sets.safe_push (set); | |
1499 | return set; | |
1500 | } | |
1501 | ||
1502 | /* Get the deallocator for DEALLOCATOR_FNDECL, creating it if necessary. */ | |
1503 | ||
1504 | const deallocator * | |
1505 | malloc_state_machine::get_or_create_deallocator (tree deallocator_fndecl) | |
1506 | { | |
1507 | deallocator **slot = m_deallocator_map.get (deallocator_fndecl); | |
1508 | if (slot) | |
1509 | return *slot; | |
1510 | ||
1511 | /* Reuse "free". */ | |
1512 | deallocator *d; | |
1513 | if (is_named_call_p (deallocator_fndecl, "free") | |
84606efb SP |
1514 | || is_std_named_call_p (deallocator_fndecl, "free") |
1515 | || is_named_call_p (deallocator_fndecl, "__builtin_free")) | |
c7e276b8 DM |
1516 | d = &m_free.m_deallocator; |
1517 | else | |
1518 | { | |
1519 | custom_deallocator *cd | |
1520 | = new custom_deallocator (this, deallocator_fndecl, | |
1521 | WORDING_DEALLOCATED); | |
1522 | m_dynamic_deallocators.safe_push (cd); | |
1523 | d = cd; | |
1524 | } | |
1525 | m_deallocator_map.put (deallocator_fndecl, d); | |
1526 | return d; | |
757bf1df DM |
1527 | } |
1528 | ||
31534ac2 SP |
1529 | /* Try to identify the function declaration either by name or as a known malloc |
1530 | builtin. */ | |
1531 | ||
1532 | static bool | |
1533 | known_allocator_p (const_tree fndecl, const gcall *call) | |
1534 | { | |
1535 | /* Either it is a function we know by name and number of arguments... */ | |
1536 | if (is_named_call_p (fndecl, "malloc", call, 1) | |
1537 | || is_named_call_p (fndecl, "calloc", call, 2) | |
1538 | || is_std_named_call_p (fndecl, "malloc", call, 1) | |
1539 | || is_std_named_call_p (fndecl, "calloc", call, 2) | |
1540 | || is_named_call_p (fndecl, "strdup", call, 1) | |
1541 | || is_named_call_p (fndecl, "strndup", call, 2)) | |
1542 | return true; | |
1543 | ||
1544 | /* ... or it is a builtin allocator that allocates objects freed with | |
1545 | __builtin_free. */ | |
1546 | if (fndecl_built_in_p (fndecl)) | |
1547 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1548 | { | |
1549 | case BUILT_IN_MALLOC: | |
1550 | case BUILT_IN_CALLOC: | |
1551 | case BUILT_IN_STRDUP: | |
1552 | case BUILT_IN_STRNDUP: | |
1553 | return true; | |
1554 | default: | |
1555 | break; | |
1556 | } | |
1557 | ||
1558 | return false; | |
1559 | } | |
1560 | ||
757bf1df DM |
1561 | /* Implementation of state_machine::on_stmt vfunc for malloc_state_machine. */ |
1562 | ||
1563 | bool | |
1564 | malloc_state_machine::on_stmt (sm_context *sm_ctxt, | |
1565 | const supernode *node, | |
1566 | const gimple *stmt) const | |
1567 | { | |
1568 | if (const gcall *call = dyn_cast <const gcall *> (stmt)) | |
1569 | if (tree callee_fndecl = sm_ctxt->get_fndecl_for_call (call)) | |
1570 | { | |
31534ac2 | 1571 | if (known_allocator_p (callee_fndecl, call)) |
757bf1df | 1572 | { |
c7e276b8 | 1573 | on_allocator_call (sm_ctxt, call, &m_free); |
1690a839 DM |
1574 | return true; |
1575 | } | |
1576 | ||
1577 | if (is_named_call_p (callee_fndecl, "operator new", call, 1)) | |
c7e276b8 | 1578 | on_allocator_call (sm_ctxt, call, &m_scalar_delete); |
1690a839 | 1579 | else if (is_named_call_p (callee_fndecl, "operator new []", call, 1)) |
c7e276b8 | 1580 | on_allocator_call (sm_ctxt, call, &m_vector_delete); |
1690a839 DM |
1581 | else if (is_named_call_p (callee_fndecl, "operator delete", call, 1) |
1582 | || is_named_call_p (callee_fndecl, "operator delete", call, 2)) | |
1583 | { | |
c7e276b8 DM |
1584 | on_deallocator_call (sm_ctxt, node, call, |
1585 | &m_scalar_delete.m_deallocator, 0); | |
1690a839 DM |
1586 | return true; |
1587 | } | |
1588 | else if (is_named_call_p (callee_fndecl, "operator delete []", call, 1)) | |
1589 | { | |
c7e276b8 DM |
1590 | on_deallocator_call (sm_ctxt, node, call, |
1591 | &m_vector_delete.m_deallocator, 0); | |
757bf1df DM |
1592 | return true; |
1593 | } | |
1594 | ||
1595 | if (is_named_call_p (callee_fndecl, "alloca", call, 1) | |
1596 | || is_named_call_p (callee_fndecl, "__builtin_alloca", call, 1)) | |
1597 | { | |
1598 | tree lhs = gimple_call_lhs (call); | |
1599 | if (lhs) | |
808f4dfe | 1600 | sm_ctxt->on_transition (node, stmt, lhs, m_start, m_non_heap); |
757bf1df DM |
1601 | return true; |
1602 | } | |
1603 | ||
1604 | if (is_named_call_p (callee_fndecl, "free", call, 1) | |
9f00b22f | 1605 | || is_std_named_call_p (callee_fndecl, "free", call, 1) |
757bf1df DM |
1606 | || is_named_call_p (callee_fndecl, "__builtin_free", call, 1)) |
1607 | { | |
c7e276b8 DM |
1608 | on_deallocator_call (sm_ctxt, node, call, |
1609 | &m_free.m_deallocator, 0); | |
757bf1df DM |
1610 | return true; |
1611 | } | |
1612 | ||
a6baafca DM |
1613 | if (is_named_call_p (callee_fndecl, "realloc", call, 2) |
1614 | || is_named_call_p (callee_fndecl, "__builtin_realloc", call, 2)) | |
1615 | { | |
1616 | on_realloc_call (sm_ctxt, node, call); | |
1617 | return true; | |
1618 | } | |
1619 | ||
cd323d97 DM |
1620 | if (unaffected_by_call_p (callee_fndecl)) |
1621 | return true; | |
1622 | ||
c7e276b8 DM |
1623 | /* Cast away const-ness for cache-like operations. */ |
1624 | malloc_state_machine *mutable_this | |
1625 | = const_cast <malloc_state_machine *> (this); | |
1626 | ||
1627 | /* Handle "__attribute__((malloc(FOO)))". */ | |
1628 | if (const deallocator_set *deallocators | |
1629 | = mutable_this->get_or_create_custom_deallocator_set | |
1630 | (callee_fndecl)) | |
1631 | { | |
1632 | tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (callee_fndecl)); | |
1633 | bool returns_nonnull | |
1634 | = lookup_attribute ("returns_nonnull", attrs); | |
1635 | on_allocator_call (sm_ctxt, call, deallocators, returns_nonnull); | |
1636 | } | |
1637 | ||
757bf1df DM |
1638 | /* Handle "__attribute__((nonnull))". */ |
1639 | { | |
1640 | tree fntype = TREE_TYPE (callee_fndecl); | |
1641 | bitmap nonnull_args = get_nonnull_args (fntype); | |
1642 | if (nonnull_args) | |
1643 | { | |
1644 | for (unsigned i = 0; i < gimple_call_num_args (stmt); i++) | |
1645 | { | |
1646 | tree arg = gimple_call_arg (stmt, i); | |
1647 | if (TREE_CODE (TREE_TYPE (arg)) != POINTER_TYPE) | |
1648 | continue; | |
1649 | /* If we have a nonnull-args, and either all pointers, or just | |
1650 | the specified pointers. */ | |
1651 | if (bitmap_empty_p (nonnull_args) | |
1652 | || bitmap_bit_p (nonnull_args, i)) | |
1653 | { | |
25ef215a DM |
1654 | state_t state = sm_ctxt->get_state (stmt, arg); |
1655 | /* Can't use a switch as the states are non-const. */ | |
1690a839 | 1656 | if (unchecked_p (state)) |
25ef215a | 1657 | { |
7d8f4240 | 1658 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a DM |
1659 | sm_ctxt->warn (node, stmt, arg, |
1660 | new possible_null_arg (*this, diag_arg, | |
1661 | callee_fndecl, | |
1662 | i)); | |
1690a839 DM |
1663 | const allocation_state *astate |
1664 | = as_a_allocation_state (state); | |
1665 | sm_ctxt->set_next_state (stmt, arg, | |
1666 | astate->get_nonnull ()); | |
25ef215a DM |
1667 | } |
1668 | else if (state == m_null) | |
1669 | { | |
7d8f4240 | 1670 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a DM |
1671 | sm_ctxt->warn (node, stmt, arg, |
1672 | new null_arg (*this, diag_arg, | |
1673 | callee_fndecl, i)); | |
1674 | sm_ctxt->set_next_state (stmt, arg, m_stop); | |
1675 | } | |
757bf1df DM |
1676 | } |
1677 | } | |
1678 | BITMAP_FREE (nonnull_args); | |
1679 | } | |
1680 | } | |
c7e276b8 DM |
1681 | |
1682 | /* Check for this after nonnull, so that if we have both | |
1683 | then we transition to "freed", rather than "checked". */ | |
1684 | unsigned dealloc_argno = fndecl_dealloc_argno (callee_fndecl); | |
1685 | if (dealloc_argno != UINT_MAX) | |
1686 | { | |
1687 | const deallocator *d | |
1688 | = mutable_this->get_or_create_deallocator (callee_fndecl); | |
1689 | on_deallocator_call (sm_ctxt, node, call, d, dealloc_argno); | |
1690 | } | |
757bf1df DM |
1691 | } |
1692 | ||
808f4dfe | 1693 | if (tree lhs = sm_ctxt->is_zero_assignment (stmt)) |
8525d1f5 | 1694 | if (any_pointer_p (lhs)) |
1690a839 | 1695 | on_zero_assignment (sm_ctxt, stmt,lhs); |
757bf1df | 1696 | |
808f4dfe DM |
1697 | /* If we have "LHS = &EXPR;" and EXPR is something other than a MEM_REF, |
1698 | transition LHS from start to non_heap. | |
1699 | Doing it for ADDR_EXPR(MEM_REF()) is likely wrong, and can lead to | |
1700 | unbounded chains of unmergeable sm-state on pointer arithmetic in loops | |
1701 | when optimization is enabled. */ | |
757bf1df DM |
1702 | if (const gassign *assign_stmt = dyn_cast <const gassign *> (stmt)) |
1703 | { | |
1704 | enum tree_code op = gimple_assign_rhs_code (assign_stmt); | |
1705 | if (op == ADDR_EXPR) | |
1706 | { | |
1707 | tree lhs = gimple_assign_lhs (assign_stmt); | |
1708 | if (lhs) | |
1709 | { | |
808f4dfe DM |
1710 | tree addr_expr = gimple_assign_rhs1 (assign_stmt); |
1711 | if (TREE_CODE (TREE_OPERAND (addr_expr, 0)) != MEM_REF) | |
1712 | sm_ctxt->on_transition (node, stmt, lhs, m_start, m_non_heap); | |
757bf1df DM |
1713 | } |
1714 | } | |
1715 | } | |
1716 | ||
1717 | /* Handle dereferences. */ | |
1718 | for (unsigned i = 0; i < gimple_num_ops (stmt); i++) | |
1719 | { | |
1720 | tree op = gimple_op (stmt, i); | |
1721 | if (!op) | |
1722 | continue; | |
1723 | if (TREE_CODE (op) == COMPONENT_REF) | |
1724 | op = TREE_OPERAND (op, 0); | |
1725 | ||
1726 | if (TREE_CODE (op) == MEM_REF) | |
1727 | { | |
1728 | tree arg = TREE_OPERAND (op, 0); | |
757bf1df | 1729 | |
25ef215a | 1730 | state_t state = sm_ctxt->get_state (stmt, arg); |
1690a839 | 1731 | if (unchecked_p (state)) |
25ef215a | 1732 | { |
0f9aa35c | 1733 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a DM |
1734 | sm_ctxt->warn (node, stmt, arg, |
1735 | new possible_null_deref (*this, diag_arg)); | |
1690a839 DM |
1736 | const allocation_state *astate = as_a_allocation_state (state); |
1737 | sm_ctxt->set_next_state (stmt, arg, astate->get_nonnull ()); | |
25ef215a DM |
1738 | } |
1739 | else if (state == m_null) | |
1740 | { | |
0f9aa35c | 1741 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a DM |
1742 | sm_ctxt->warn (node, stmt, arg, |
1743 | new null_deref (*this, diag_arg)); | |
1744 | sm_ctxt->set_next_state (stmt, arg, m_stop); | |
1745 | } | |
1690a839 | 1746 | else if (freed_p (state)) |
25ef215a | 1747 | { |
0f9aa35c | 1748 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
1690a839 | 1749 | const allocation_state *astate = as_a_allocation_state (state); |
25ef215a | 1750 | sm_ctxt->warn (node, stmt, arg, |
1690a839 | 1751 | new use_after_free (*this, diag_arg, |
c7e276b8 | 1752 | astate->m_deallocator)); |
25ef215a DM |
1753 | sm_ctxt->set_next_state (stmt, arg, m_stop); |
1754 | } | |
757bf1df DM |
1755 | } |
1756 | } | |
1757 | return false; | |
1758 | } | |
1759 | ||
c7e276b8 DM |
1760 | /* Handle a call to an allocator. |
1761 | RETURNS_NONNULL is true if CALL is to a fndecl known to have | |
1762 | __attribute__((returns_nonnull)). */ | |
1690a839 DM |
1763 | |
1764 | void | |
1765 | malloc_state_machine::on_allocator_call (sm_context *sm_ctxt, | |
1766 | const gcall *call, | |
c7e276b8 DM |
1767 | const deallocator_set *deallocators, |
1768 | bool returns_nonnull) const | |
1690a839 DM |
1769 | { |
1770 | tree lhs = gimple_call_lhs (call); | |
1771 | if (lhs) | |
1772 | { | |
1773 | if (sm_ctxt->get_state (call, lhs) == m_start) | |
c7e276b8 DM |
1774 | sm_ctxt->set_next_state (call, lhs, |
1775 | (returns_nonnull | |
1776 | ? deallocators->m_nonnull | |
1777 | : deallocators->m_unchecked)); | |
1690a839 DM |
1778 | } |
1779 | else | |
1780 | { | |
1781 | /* TODO: report leak. */ | |
1782 | } | |
1783 | } | |
1784 | ||
1785 | void | |
1786 | malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt, | |
1787 | const supernode *node, | |
1788 | const gcall *call, | |
c7e276b8 DM |
1789 | const deallocator *d, |
1790 | unsigned argno) const | |
1690a839 | 1791 | { |
c7e276b8 DM |
1792 | if (argno >= gimple_call_num_args (call)) |
1793 | return; | |
1794 | tree arg = gimple_call_arg (call, argno); | |
1690a839 DM |
1795 | |
1796 | state_t state = sm_ctxt->get_state (call, arg); | |
1797 | ||
1798 | /* start/unchecked/nonnull -> freed. */ | |
1799 | if (state == m_start) | |
c7e276b8 | 1800 | sm_ctxt->set_next_state (call, arg, d->m_freed); |
1690a839 DM |
1801 | else if (unchecked_p (state) || nonnull_p (state)) |
1802 | { | |
1803 | const allocation_state *astate = as_a_allocation_state (state); | |
c7e276b8 DM |
1804 | gcc_assert (astate->m_deallocators); |
1805 | if (!astate->m_deallocators->contains_p (d)) | |
1690a839 DM |
1806 | { |
1807 | /* Wrong allocator. */ | |
0f9aa35c | 1808 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
c7e276b8 | 1809 | pending_diagnostic *pd |
1690a839 | 1810 | = new mismatching_deallocation (*this, diag_arg, |
c7e276b8 DM |
1811 | astate->m_deallocators, |
1812 | d); | |
1813 | sm_ctxt->warn (node, call, arg, pd); | |
1690a839 | 1814 | } |
c7e276b8 | 1815 | sm_ctxt->set_next_state (call, arg, d->m_freed); |
1690a839 DM |
1816 | } |
1817 | ||
1818 | /* Keep state "null" as-is, rather than transitioning to "freed"; | |
1819 | we don't want to complain about double-free of NULL. */ | |
c7e276b8 | 1820 | else if (state == d->m_freed) |
1690a839 DM |
1821 | { |
1822 | /* freed -> stop, with warning. */ | |
0f9aa35c | 1823 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
1690a839 | 1824 | sm_ctxt->warn (node, call, arg, |
c7e276b8 | 1825 | new double_free (*this, diag_arg, d->m_name)); |
1690a839 DM |
1826 | sm_ctxt->set_next_state (call, arg, m_stop); |
1827 | } | |
1828 | else if (state == m_non_heap) | |
1829 | { | |
1830 | /* non-heap -> stop, with warning. */ | |
0f9aa35c | 1831 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
1690a839 DM |
1832 | sm_ctxt->warn (node, call, arg, |
1833 | new free_of_non_heap (*this, diag_arg, | |
c7e276b8 | 1834 | d->m_name)); |
1690a839 DM |
1835 | sm_ctxt->set_next_state (call, arg, m_stop); |
1836 | } | |
1837 | } | |
1838 | ||
a6baafca DM |
1839 | /* Implementation of realloc(3): |
1840 | ||
1841 | void *realloc(void *ptr, size_t size); | |
1842 | ||
1843 | realloc(3) is awkward. | |
1844 | ||
1845 | We currently don't have a way to express multiple possible outcomes | |
1846 | from a function call, "bifurcating" the state such as: | |
1847 | - success: non-NULL is returned | |
1848 | - failure: NULL is returned, existing buffer is not freed. | |
1849 | or even an N-way state split e.g.: | |
1850 | - buffer grew successfully in-place | |
1851 | - buffer was successfully moved to a larger allocation | |
1852 | - buffer was successfully contracted | |
1853 | - realloc failed, returning NULL, without freeing existing buffer. | |
1854 | (PR analyzer/99260 tracks this) | |
1855 | ||
1856 | Given that we can currently only express one outcome, eliminate | |
1857 | false positives by dropping state from the buffer. */ | |
1858 | ||
1859 | void | |
1860 | malloc_state_machine::on_realloc_call (sm_context *sm_ctxt, | |
1861 | const supernode *node ATTRIBUTE_UNUSED, | |
1862 | const gcall *call) const | |
1863 | { | |
1864 | tree ptr = gimple_call_arg (call, 0); | |
a6baafca DM |
1865 | |
1866 | state_t state = sm_ctxt->get_state (call, ptr); | |
1867 | ||
1868 | /* Detect mismatches. */ | |
1869 | if (unchecked_p (state) || nonnull_p (state)) | |
1870 | { | |
1871 | const allocation_state *astate = as_a_allocation_state (state); | |
1872 | gcc_assert (astate->m_deallocators); | |
1873 | if (astate->m_deallocators != &m_free) | |
1874 | { | |
1875 | /* Wrong allocator. */ | |
0f9aa35c | 1876 | tree diag_ptr = sm_ctxt->get_diagnostic_tree (ptr); |
a6baafca DM |
1877 | pending_diagnostic *pd |
1878 | = new mismatching_deallocation (*this, diag_ptr, | |
1879 | astate->m_deallocators, | |
1880 | &m_realloc); | |
1881 | sm_ctxt->warn (node, call, ptr, pd); | |
1882 | } | |
1883 | } | |
1884 | ||
1885 | /* Transition ptr to "stop" state. */ | |
1886 | sm_ctxt->set_next_state (call, ptr, m_stop); | |
1887 | } | |
1888 | ||
8525d1f5 DM |
1889 | /* Implementation of state_machine::on_phi vfunc for malloc_state_machine. */ |
1890 | ||
1891 | void | |
1892 | malloc_state_machine::on_phi (sm_context *sm_ctxt, | |
1690a839 | 1893 | const supernode *node ATTRIBUTE_UNUSED, |
8525d1f5 DM |
1894 | const gphi *phi, |
1895 | tree rhs) const | |
1896 | { | |
1897 | if (zerop (rhs)) | |
1898 | { | |
1899 | tree lhs = gimple_phi_result (phi); | |
1690a839 | 1900 | on_zero_assignment (sm_ctxt, phi, lhs); |
8525d1f5 DM |
1901 | } |
1902 | } | |
1903 | ||
757bf1df DM |
1904 | /* Implementation of state_machine::on_condition vfunc for malloc_state_machine. |
1905 | Potentially transition state 'unchecked' to 'nonnull' or to 'null'. */ | |
1906 | ||
1907 | void | |
1908 | malloc_state_machine::on_condition (sm_context *sm_ctxt, | |
1690a839 | 1909 | const supernode *node ATTRIBUTE_UNUSED, |
757bf1df | 1910 | const gimple *stmt, |
48e8a7a6 | 1911 | const svalue *lhs, |
757bf1df | 1912 | enum tree_code op, |
48e8a7a6 | 1913 | const svalue *rhs) const |
757bf1df | 1914 | { |
48e8a7a6 | 1915 | if (!rhs->all_zeroes_p ()) |
757bf1df DM |
1916 | return; |
1917 | ||
1918 | if (!any_pointer_p (lhs)) | |
1919 | return; | |
1920 | if (!any_pointer_p (rhs)) | |
1921 | return; | |
1922 | ||
1923 | if (op == NE_EXPR) | |
1924 | { | |
1925 | log ("got 'ARG != 0' match"); | |
1690a839 DM |
1926 | state_t s = sm_ctxt->get_state (stmt, lhs); |
1927 | if (unchecked_p (s)) | |
1928 | { | |
1929 | const allocation_state *astate = as_a_allocation_state (s); | |
1930 | sm_ctxt->set_next_state (stmt, lhs, astate->get_nonnull ()); | |
1931 | } | |
757bf1df DM |
1932 | } |
1933 | else if (op == EQ_EXPR) | |
1934 | { | |
1935 | log ("got 'ARG == 0' match"); | |
1690a839 DM |
1936 | state_t s = sm_ctxt->get_state (stmt, lhs); |
1937 | if (unchecked_p (s)) | |
1938 | sm_ctxt->set_next_state (stmt, lhs, m_null); | |
757bf1df DM |
1939 | } |
1940 | } | |
1941 | ||
1942 | /* Implementation of state_machine::can_purge_p vfunc for malloc_state_machine. | |
1943 | Don't allow purging of pointers in state 'unchecked' or 'nonnull' | |
1944 | (to avoid false leak reports). */ | |
1945 | ||
1946 | bool | |
1947 | malloc_state_machine::can_purge_p (state_t s) const | |
1948 | { | |
1690a839 DM |
1949 | enum resource_state rs = get_rs (s); |
1950 | return rs != RS_UNCHECKED && rs != RS_NONNULL; | |
757bf1df DM |
1951 | } |
1952 | ||
1953 | /* Implementation of state_machine::on_leak vfunc for malloc_state_machine | |
1954 | (for complaining about leaks of pointers in state 'unchecked' and | |
1955 | 'nonnull'). */ | |
1956 | ||
1957 | pending_diagnostic * | |
1958 | malloc_state_machine::on_leak (tree var) const | |
1959 | { | |
1960 | return new malloc_leak (*this, var); | |
1961 | } | |
1962 | ||
808f4dfe DM |
1963 | /* Implementation of state_machine::reset_when_passed_to_unknown_fn_p vfunc |
1964 | for malloc_state_machine. */ | |
1965 | ||
1966 | bool | |
1967 | malloc_state_machine::reset_when_passed_to_unknown_fn_p (state_t s, | |
1968 | bool is_mutable) const | |
1969 | { | |
1970 | /* An on-stack ptr doesn't stop being stack-allocated when passed to an | |
1971 | unknown fn. */ | |
1972 | if (s == m_non_heap) | |
1973 | return false; | |
1974 | ||
1975 | /* Otherwise, pointers passed as non-const can be freed. */ | |
1976 | return is_mutable; | |
1977 | } | |
1978 | ||
cd323d97 DM |
1979 | /* Return true if calls to FNDECL are known to not affect this sm-state. */ |
1980 | ||
1981 | bool | |
1982 | malloc_state_machine::unaffected_by_call_p (tree fndecl) | |
1983 | { | |
1984 | /* A set of functions that are known to not affect allocation | |
1985 | status, even if we haven't fully modelled the rest of their | |
1986 | behavior yet. */ | |
1987 | static const char * const funcnames[] = { | |
1988 | /* This array must be kept sorted. */ | |
1989 | "strsep", | |
1990 | }; | |
1991 | const size_t count | |
1992 | = sizeof(funcnames) / sizeof (funcnames[0]); | |
1993 | function_set fs (funcnames, count); | |
1994 | ||
1995 | if (fs.contains_decl_p (fndecl)) | |
1996 | return true; | |
1997 | ||
1998 | return false; | |
1999 | } | |
2000 | ||
8525d1f5 DM |
2001 | /* Shared logic for handling GIMPLE_ASSIGNs and GIMPLE_PHIs that |
2002 | assign zero to LHS. */ | |
2003 | ||
2004 | void | |
2005 | malloc_state_machine::on_zero_assignment (sm_context *sm_ctxt, | |
8525d1f5 DM |
2006 | const gimple *stmt, |
2007 | tree lhs) const | |
2008 | { | |
1690a839 DM |
2009 | state_t s = sm_ctxt->get_state (stmt, lhs); |
2010 | enum resource_state rs = get_rs (s); | |
2011 | if (rs == RS_START | |
2012 | || rs == RS_UNCHECKED | |
2013 | || rs == RS_NONNULL | |
2014 | || rs == RS_FREED) | |
2015 | sm_ctxt->set_next_state (stmt, lhs, m_null); | |
8525d1f5 DM |
2016 | } |
2017 | ||
757bf1df DM |
2018 | } // anonymous namespace |
2019 | ||
2020 | /* Internal interface to this file. */ | |
2021 | ||
2022 | state_machine * | |
2023 | make_malloc_state_machine (logger *logger) | |
2024 | { | |
2025 | return new malloc_state_machine (logger); | |
2026 | } | |
2027 | ||
75038aa6 DM |
2028 | } // namespace ana |
2029 | ||
757bf1df | 2030 | #endif /* #if ENABLE_ANALYZER */ |