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757bf1df | 1 | /* A state machine for detecting misuses of the malloc/free API. |
83ffe9cd | 2 | Copyright (C) 2019-2023 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" | |
6341f14e | 22 | #define INCLUDE_MEMORY |
757bf1df DM |
23 | #include "system.h" |
24 | #include "coretypes.h" | |
6341f14e | 25 | #include "make-unique.h" |
757bf1df DM |
26 | #include "tree.h" |
27 | #include "function.h" | |
28 | #include "basic-block.h" | |
29 | #include "gimple.h" | |
30 | #include "options.h" | |
31 | #include "bitmap.h" | |
32 | #include "diagnostic-path.h" | |
33 | #include "diagnostic-metadata.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 "analyzer/call-string.h" |
40 | #include "analyzer/program-point.h" | |
41 | #include "analyzer/store.h" | |
42 | #include "analyzer/region-model.h" | |
861c917a | 43 | #include "analyzer/call-details.h" |
c7e276b8 DM |
44 | #include "stringpool.h" |
45 | #include "attribs.h" | |
cd323d97 | 46 | #include "analyzer/function-set.h" |
eafa9d96 | 47 | #include "analyzer/program-state.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 | ||
5c6546ca DM |
91 | /* State for a pointer that's been unconditionally dereferenced. */ |
92 | RS_ASSUMED_NON_NULL, | |
93 | ||
1690a839 DM |
94 | /* State for a pointer that's known to be NULL. */ |
95 | RS_NULL, | |
96 | ||
97 | /* State for a pointer that's known to not be on the heap (e.g. to a local | |
98 | or global). */ | |
99 | RS_NON_HEAP, | |
100 | ||
101 | /* Stop state, for pointers we don't want to track any more. */ | |
102 | RS_STOP, | |
103 | ||
c7e276b8 | 104 | /* States that relate to a specific deallocator_set. */ |
1690a839 | 105 | |
c7e276b8 | 106 | /* State for a pointer returned from an allocator that hasn't |
1690a839 DM |
107 | been checked for NULL. |
108 | It could be a pointer to heap-allocated memory, or could be NULL. */ | |
109 | RS_UNCHECKED, | |
110 | ||
c7e276b8 | 111 | /* State for a pointer returned from an allocator, |
1690a839 DM |
112 | known to be non-NULL. */ |
113 | RS_NONNULL, | |
114 | ||
c7e276b8 | 115 | /* State for a pointer passed to a deallocator. */ |
1690a839 DM |
116 | RS_FREED |
117 | }; | |
118 | ||
c7e276b8 DM |
119 | /* Custom state subclass, which can optionally refer to an a |
120 | deallocator_set. */ | |
1690a839 DM |
121 | |
122 | struct allocation_state : public state_machine::state | |
123 | { | |
124 | allocation_state (const char *name, unsigned id, | |
c7e276b8 DM |
125 | enum resource_state rs, |
126 | const deallocator_set *deallocators, | |
127 | const deallocator *deallocator) | |
128 | : state (name, id), m_rs (rs), | |
129 | m_deallocators (deallocators), | |
130 | m_deallocator (deallocator) | |
1690a839 DM |
131 | {} |
132 | ||
5c6546ca | 133 | void dump_to_pp (pretty_printer *pp) const override; |
1690a839 DM |
134 | |
135 | const allocation_state *get_nonnull () const; | |
136 | ||
137 | enum resource_state m_rs; | |
c7e276b8 DM |
138 | const deallocator_set *m_deallocators; |
139 | const deallocator *m_deallocator; | |
1690a839 DM |
140 | }; |
141 | ||
5c6546ca DM |
142 | /* Custom state subclass, for the "assumed-non-null" state |
143 | where the assumption happens in a particular frame. */ | |
144 | ||
145 | struct assumed_non_null_state : public allocation_state | |
146 | { | |
147 | assumed_non_null_state (const char *name, unsigned id, | |
148 | const frame_region *frame) | |
149 | : allocation_state (name, id, RS_ASSUMED_NON_NULL, | |
150 | NULL, NULL), | |
151 | m_frame (frame) | |
152 | { | |
153 | gcc_assert (m_frame); | |
154 | } | |
155 | ||
156 | void dump_to_pp (pretty_printer *pp) const final override; | |
157 | ||
158 | const frame_region *m_frame; | |
159 | }; | |
160 | ||
1690a839 DM |
161 | /* An enum for choosing which wording to use in various diagnostics |
162 | when describing deallocations. */ | |
163 | ||
164 | enum wording | |
165 | { | |
166 | WORDING_FREED, | |
c7e276b8 | 167 | WORDING_DELETED, |
a6baafca DM |
168 | WORDING_DEALLOCATED, |
169 | WORDING_REALLOCATED | |
1690a839 DM |
170 | }; |
171 | ||
c7e276b8 DM |
172 | /* Base class representing a deallocation function, |
173 | either a built-in one we know about, or one exposed via | |
174 | __attribute__((malloc(DEALLOCATOR))). */ | |
1690a839 | 175 | |
c7e276b8 | 176 | struct deallocator |
1690a839 | 177 | { |
c7e276b8 DM |
178 | hashval_t hash () const; |
179 | void dump_to_pp (pretty_printer *pp) const; | |
180 | static int cmp (const deallocator *a, const deallocator *b); | |
181 | static int cmp_ptr_ptr (const void *, const void *); | |
1690a839 | 182 | |
c7e276b8 | 183 | /* Name to use in diagnostics. */ |
1690a839 DM |
184 | const char *m_name; |
185 | ||
c7e276b8 DM |
186 | /* Which wording to use in diagnostics. */ |
187 | enum wording m_wording; | |
188 | ||
189 | /* State for a value passed to one of the deallocators. */ | |
190 | state_machine::state_t m_freed; | |
191 | ||
192 | protected: | |
193 | deallocator (malloc_state_machine *sm, | |
194 | const char *name, | |
195 | enum wording wording); | |
196 | }; | |
197 | ||
198 | /* Subclass representing a predefined deallocator. | |
199 | e.g. "delete []", without needing a specific FUNCTION_DECL | |
200 | ahead of time. */ | |
201 | ||
202 | struct standard_deallocator : public deallocator | |
203 | { | |
204 | standard_deallocator (malloc_state_machine *sm, | |
205 | const char *name, | |
206 | enum wording wording); | |
207 | }; | |
208 | ||
209 | /* Subclass representing a user-defined deallocator | |
210 | via __attribute__((malloc(DEALLOCATOR))) given | |
211 | a specific FUNCTION_DECL. */ | |
212 | ||
213 | struct custom_deallocator : public deallocator | |
214 | { | |
215 | custom_deallocator (malloc_state_machine *sm, | |
216 | tree deallocator_fndecl, | |
217 | enum wording wording) | |
218 | : deallocator (sm, IDENTIFIER_POINTER (DECL_NAME (deallocator_fndecl)), | |
219 | wording) | |
220 | { | |
221 | } | |
222 | }; | |
223 | ||
224 | /* Base class representing a set of possible deallocators. | |
225 | Often this will be just a single deallocator, but some | |
226 | allocators have multiple valid deallocators (e.g. the result of | |
227 | "fopen" can be closed by either "fclose" or "freopen"). */ | |
228 | ||
229 | struct deallocator_set | |
230 | { | |
231 | deallocator_set (malloc_state_machine *sm, | |
232 | enum wording wording); | |
233 | virtual ~deallocator_set () {} | |
234 | ||
235 | virtual bool contains_p (const deallocator *d) const = 0; | |
236 | virtual const deallocator *maybe_get_single () const = 0; | |
237 | virtual void dump_to_pp (pretty_printer *pp) const = 0; | |
238 | void dump () const; | |
1690a839 DM |
239 | |
240 | /* Which wording to use in diagnostics. */ | |
241 | enum wording m_wording; | |
242 | ||
c7e276b8 | 243 | /* Pointers to states. |
1690a839 DM |
244 | These states are owned by the state_machine base class. */ |
245 | ||
c7e276b8 | 246 | /* State for an unchecked result from an allocator using this set. */ |
1690a839 DM |
247 | state_machine::state_t m_unchecked; |
248 | ||
c7e276b8 | 249 | /* State for a known non-NULL result from such an allocator. */ |
1690a839 | 250 | state_machine::state_t m_nonnull; |
c7e276b8 | 251 | }; |
1690a839 | 252 | |
c7e276b8 DM |
253 | /* Subclass of deallocator_set representing a set of deallocators |
254 | defined by one or more __attribute__((malloc(DEALLOCATOR))). */ | |
255 | ||
256 | struct custom_deallocator_set : public deallocator_set | |
257 | { | |
258 | typedef const auto_vec <const deallocator *> *key_t; | |
259 | ||
260 | custom_deallocator_set (malloc_state_machine *sm, | |
261 | const auto_vec <const deallocator *> *vec, | |
262 | //const char *name, | |
263 | //const char *dealloc_funcname, | |
264 | //unsigned arg_idx, | |
265 | enum wording wording); | |
266 | ||
ff171cb1 DM |
267 | bool contains_p (const deallocator *d) const final override; |
268 | const deallocator *maybe_get_single () const final override; | |
269 | void dump_to_pp (pretty_printer *pp) const final override; | |
c7e276b8 DM |
270 | |
271 | auto_vec <const deallocator *> m_deallocator_vec; | |
272 | }; | |
273 | ||
274 | /* Subclass of deallocator_set representing a set of deallocators | |
275 | with a single standard_deallocator, e.g. "delete []". */ | |
276 | ||
277 | struct standard_deallocator_set : public deallocator_set | |
278 | { | |
279 | standard_deallocator_set (malloc_state_machine *sm, | |
280 | const char *name, | |
281 | enum wording wording); | |
282 | ||
ff171cb1 DM |
283 | bool contains_p (const deallocator *d) const final override; |
284 | const deallocator *maybe_get_single () const final override; | |
285 | void dump_to_pp (pretty_printer *pp) const final override; | |
c7e276b8 DM |
286 | |
287 | standard_deallocator m_deallocator; | |
288 | }; | |
289 | ||
290 | /* Traits class for ensuring uniqueness of deallocator_sets within | |
291 | malloc_state_machine. */ | |
292 | ||
293 | struct deallocator_set_map_traits | |
294 | { | |
295 | typedef custom_deallocator_set::key_t key_type; | |
296 | typedef custom_deallocator_set *value_type; | |
297 | typedef custom_deallocator_set *compare_type; | |
298 | ||
299 | static inline hashval_t hash (const key_type &k) | |
300 | { | |
301 | gcc_assert (k != NULL); | |
302 | gcc_assert (k != reinterpret_cast<key_type> (1)); | |
303 | ||
304 | hashval_t result = 0; | |
305 | unsigned i; | |
306 | const deallocator *d; | |
307 | FOR_EACH_VEC_ELT (*k, i, d) | |
308 | result ^= d->hash (); | |
309 | return result; | |
310 | } | |
311 | static inline bool equal_keys (const key_type &k1, const key_type &k2) | |
312 | { | |
313 | if (k1->length () != k2->length ()) | |
314 | return false; | |
315 | ||
316 | for (unsigned i = 0; i < k1->length (); i++) | |
317 | if ((*k1)[i] != (*k2)[i]) | |
318 | return false; | |
319 | ||
320 | return true; | |
321 | } | |
322 | template <typename T> | |
323 | static inline void remove (T &) | |
324 | { | |
325 | /* empty; the nodes are handled elsewhere. */ | |
326 | } | |
327 | template <typename T> | |
328 | static inline void mark_deleted (T &entry) | |
329 | { | |
330 | entry.m_key = reinterpret_cast<key_type> (1); | |
331 | } | |
332 | template <typename T> | |
333 | static inline void mark_empty (T &entry) | |
334 | { | |
335 | entry.m_key = NULL; | |
336 | } | |
337 | template <typename T> | |
338 | static inline bool is_deleted (const T &entry) | |
339 | { | |
340 | return entry.m_key == reinterpret_cast<key_type> (1); | |
341 | } | |
342 | template <typename T> | |
343 | static inline bool is_empty (const T &entry) | |
344 | { | |
345 | return entry.m_key == NULL; | |
346 | } | |
347 | static const bool empty_zero_p = false; | |
1690a839 DM |
348 | }; |
349 | ||
757bf1df DM |
350 | /* A state machine for detecting misuses of the malloc/free API. |
351 | ||
352 | See sm-malloc.dot for an overview (keep this in-sync with that file). */ | |
353 | ||
354 | class malloc_state_machine : public state_machine | |
355 | { | |
356 | public: | |
1690a839 DM |
357 | typedef allocation_state custom_data_t; |
358 | ||
757bf1df | 359 | malloc_state_machine (logger *logger); |
c7e276b8 | 360 | ~malloc_state_machine (); |
757bf1df | 361 | |
1690a839 | 362 | state_t |
c7e276b8 DM |
363 | add_state (const char *name, enum resource_state rs, |
364 | const deallocator_set *deallocators, | |
365 | const deallocator *deallocator); | |
1690a839 | 366 | |
ff171cb1 | 367 | bool inherited_state_p () const final override { return false; } |
757bf1df | 368 | |
808f4dfe | 369 | state_machine::state_t |
ff171cb1 | 370 | get_default_state (const svalue *sval) const final override |
808f4dfe DM |
371 | { |
372 | if (tree cst = sval->maybe_get_constant ()) | |
373 | { | |
374 | if (zerop (cst)) | |
375 | return m_null; | |
376 | } | |
377 | if (const region_svalue *ptr = sval->dyn_cast_region_svalue ()) | |
378 | { | |
379 | const region *reg = ptr->get_pointee (); | |
a61aaee6 DM |
380 | switch (reg->get_memory_space ()) |
381 | { | |
382 | default: | |
383 | break; | |
384 | case MEMSPACE_CODE: | |
385 | case MEMSPACE_GLOBALS: | |
386 | case MEMSPACE_STACK: | |
387 | case MEMSPACE_READONLY_DATA: | |
388 | return m_non_heap; | |
389 | } | |
808f4dfe DM |
390 | } |
391 | return m_start; | |
392 | } | |
393 | ||
757bf1df DM |
394 | bool on_stmt (sm_context *sm_ctxt, |
395 | const supernode *node, | |
ff171cb1 | 396 | const gimple *stmt) const final override; |
757bf1df | 397 | |
8525d1f5 DM |
398 | void on_phi (sm_context *sm_ctxt, |
399 | const supernode *node, | |
400 | const gphi *phi, | |
ff171cb1 | 401 | tree rhs) const final override; |
8525d1f5 | 402 | |
757bf1df DM |
403 | void on_condition (sm_context *sm_ctxt, |
404 | const supernode *node, | |
405 | const gimple *stmt, | |
48e8a7a6 | 406 | const svalue *lhs, |
757bf1df | 407 | enum tree_code op, |
ff171cb1 | 408 | const svalue *rhs) const final override; |
757bf1df | 409 | |
5c6546ca DM |
410 | void on_pop_frame (sm_state_map *smap, |
411 | const frame_region *) const final override; | |
412 | ||
ff171cb1 | 413 | bool can_purge_p (state_t s) const final override; |
6341f14e | 414 | std::unique_ptr<pending_diagnostic> on_leak (tree var) const final override; |
757bf1df | 415 | |
808f4dfe | 416 | bool reset_when_passed_to_unknown_fn_p (state_t s, |
ff171cb1 | 417 | bool is_mutable) const final override; |
808f4dfe | 418 | |
5c6546ca DM |
419 | state_t |
420 | maybe_get_merged_states_nonequal (state_t state_a, | |
421 | state_t state_b) const final override; | |
422 | ||
cd323d97 DM |
423 | static bool unaffected_by_call_p (tree fndecl); |
424 | ||
5c6546ca DM |
425 | void maybe_assume_non_null (sm_context *sm_ctxt, |
426 | tree ptr, | |
427 | const gimple *stmt) const; | |
428 | ||
eafa9d96 DM |
429 | void on_realloc_with_move (region_model *model, |
430 | sm_state_map *smap, | |
431 | const svalue *old_ptr_sval, | |
432 | const svalue *new_ptr_sval, | |
433 | const extrinsic_state &ext_state) const; | |
434 | ||
c7e276b8 DM |
435 | standard_deallocator_set m_free; |
436 | standard_deallocator_set m_scalar_delete; | |
437 | standard_deallocator_set m_vector_delete; | |
1690a839 | 438 | |
a6baafca DM |
439 | standard_deallocator m_realloc; |
440 | ||
1690a839 | 441 | /* States that are independent of api. */ |
757bf1df | 442 | |
5c6546ca DM |
443 | /* States for a pointer that's been unconditionally dereferenced |
444 | in a particular stack frame. */ | |
445 | hash_map<const frame_region *, state_t> m_assumed_non_null; | |
446 | ||
757bf1df DM |
447 | /* State for a pointer that's known to be NULL. */ |
448 | state_t m_null; | |
449 | ||
757bf1df DM |
450 | /* State for a pointer that's known to not be on the heap (e.g. to a local |
451 | or global). */ | |
452 | state_t m_non_heap; // TODO: or should this be a different state machine? | |
453 | // or do we need child values etc? | |
454 | ||
455 | /* Stop state, for pointers we don't want to track any more. */ | |
456 | state_t m_stop; | |
8525d1f5 DM |
457 | |
458 | private: | |
c7e276b8 DM |
459 | const custom_deallocator_set * |
460 | get_or_create_custom_deallocator_set (tree allocator_fndecl); | |
461 | custom_deallocator_set * | |
462 | maybe_create_custom_deallocator_set (tree allocator_fndecl); | |
463 | const deallocator * | |
464 | get_or_create_deallocator (tree deallocator_fndecl); | |
465 | ||
5c6546ca DM |
466 | state_t |
467 | get_or_create_assumed_non_null_state_for_frame (const frame_region *frame); | |
468 | ||
469 | void | |
470 | maybe_complain_about_deref_before_check (sm_context *sm_ctxt, | |
471 | const supernode *node, | |
472 | const gimple *stmt, | |
473 | const assumed_non_null_state *, | |
474 | tree ptr) const; | |
475 | ||
1690a839 DM |
476 | void on_allocator_call (sm_context *sm_ctxt, |
477 | const gcall *call, | |
c7e276b8 DM |
478 | const deallocator_set *deallocators, |
479 | bool returns_nonnull = false) const; | |
a61aaee6 DM |
480 | void handle_free_of_non_heap (sm_context *sm_ctxt, |
481 | const supernode *node, | |
482 | const gcall *call, | |
483 | tree arg, | |
484 | const deallocator *d) const; | |
1690a839 DM |
485 | void on_deallocator_call (sm_context *sm_ctxt, |
486 | const supernode *node, | |
487 | const gcall *call, | |
c7e276b8 DM |
488 | const deallocator *d, |
489 | unsigned argno) const; | |
a6baafca DM |
490 | void on_realloc_call (sm_context *sm_ctxt, |
491 | const supernode *node, | |
492 | const gcall *call) const; | |
8525d1f5 | 493 | void on_zero_assignment (sm_context *sm_ctxt, |
8525d1f5 DM |
494 | const gimple *stmt, |
495 | tree lhs) const; | |
c7e276b8 DM |
496 | |
497 | /* A map for consolidating deallocators so that they are | |
498 | unique per deallocator FUNCTION_DECL. */ | |
499 | typedef hash_map<tree, deallocator *> deallocator_map_t; | |
500 | deallocator_map_t m_deallocator_map; | |
501 | ||
502 | /* Memoized lookups from FUNCTION_DECL to custom_deallocator_set *. */ | |
503 | typedef hash_map<tree, custom_deallocator_set *> deallocator_set_cache_t; | |
504 | deallocator_set_cache_t m_custom_deallocator_set_cache; | |
505 | ||
506 | /* A map for consolidating custom_deallocator_set instances. */ | |
507 | typedef hash_map<custom_deallocator_set::key_t, | |
508 | custom_deallocator_set *, | |
509 | deallocator_set_map_traits> custom_deallocator_set_map_t; | |
510 | custom_deallocator_set_map_t m_custom_deallocator_set_map; | |
511 | ||
512 | /* Record of dynamically-allocated objects, for cleanup. */ | |
513 | auto_vec <custom_deallocator_set *> m_dynamic_sets; | |
514 | auto_vec <custom_deallocator *> m_dynamic_deallocators; | |
757bf1df DM |
515 | }; |
516 | ||
c7e276b8 | 517 | /* struct deallocator. */ |
1690a839 | 518 | |
c7e276b8 DM |
519 | deallocator::deallocator (malloc_state_machine *sm, |
520 | const char *name, | |
521 | enum wording wording) | |
1690a839 | 522 | : m_name (name), |
1690a839 | 523 | m_wording (wording), |
c7e276b8 DM |
524 | m_freed (sm->add_state ("freed", RS_FREED, NULL, this)) |
525 | { | |
526 | } | |
527 | ||
528 | hashval_t | |
529 | deallocator::hash () const | |
530 | { | |
531 | return (hashval_t)m_freed->get_id (); | |
532 | } | |
533 | ||
534 | void | |
535 | deallocator::dump_to_pp (pretty_printer *pp) const | |
536 | { | |
537 | pp_printf (pp, "%qs", m_name); | |
538 | } | |
539 | ||
540 | int | |
541 | deallocator::cmp (const deallocator *a, const deallocator *b) | |
542 | { | |
543 | return (int)a->m_freed->get_id () - (int)b->m_freed->get_id (); | |
544 | } | |
545 | ||
546 | int | |
547 | deallocator::cmp_ptr_ptr (const void *a, const void *b) | |
548 | { | |
549 | return cmp (*(const deallocator * const *)a, | |
550 | *(const deallocator * const *)b); | |
551 | } | |
552 | ||
553 | ||
554 | /* struct standard_deallocator : public deallocator. */ | |
555 | ||
556 | standard_deallocator::standard_deallocator (malloc_state_machine *sm, | |
557 | const char *name, | |
558 | enum wording wording) | |
559 | : deallocator (sm, name, wording) | |
1690a839 DM |
560 | { |
561 | } | |
562 | ||
c7e276b8 DM |
563 | /* struct deallocator_set. */ |
564 | ||
565 | deallocator_set::deallocator_set (malloc_state_machine *sm, | |
566 | enum wording wording) | |
567 | : m_wording (wording), | |
568 | m_unchecked (sm->add_state ("unchecked", RS_UNCHECKED, this, NULL)), | |
569 | m_nonnull (sm->add_state ("nonnull", RS_NONNULL, this, NULL)) | |
570 | { | |
571 | } | |
572 | ||
573 | /* Dump a description of this deallocator_set to stderr. */ | |
574 | ||
575 | DEBUG_FUNCTION void | |
576 | deallocator_set::dump () const | |
577 | { | |
578 | pretty_printer pp; | |
579 | pp_show_color (&pp) = pp_show_color (global_dc->printer); | |
580 | pp.buffer->stream = stderr; | |
581 | dump_to_pp (&pp); | |
582 | pp_newline (&pp); | |
583 | pp_flush (&pp); | |
584 | } | |
585 | ||
586 | /* struct custom_deallocator_set : public deallocator_set. */ | |
587 | ||
588 | custom_deallocator_set:: | |
589 | custom_deallocator_set (malloc_state_machine *sm, | |
590 | const auto_vec <const deallocator *> *vec, | |
591 | enum wording wording) | |
592 | : deallocator_set (sm, wording), | |
593 | m_deallocator_vec (vec->length ()) | |
594 | { | |
595 | unsigned i; | |
596 | const deallocator *d; | |
597 | FOR_EACH_VEC_ELT (*vec, i, d) | |
598 | m_deallocator_vec.safe_push (d); | |
599 | } | |
600 | ||
601 | bool | |
602 | custom_deallocator_set::contains_p (const deallocator *d) const | |
603 | { | |
604 | unsigned i; | |
605 | const deallocator *cd; | |
606 | FOR_EACH_VEC_ELT (m_deallocator_vec, i, cd) | |
607 | if (cd == d) | |
608 | return true; | |
609 | return false; | |
610 | } | |
611 | ||
612 | const deallocator * | |
613 | custom_deallocator_set::maybe_get_single () const | |
614 | { | |
615 | if (m_deallocator_vec.length () == 1) | |
616 | return m_deallocator_vec[0]; | |
617 | return NULL; | |
618 | } | |
619 | ||
620 | void | |
621 | custom_deallocator_set::dump_to_pp (pretty_printer *pp) const | |
622 | { | |
623 | pp_character (pp, '{'); | |
624 | unsigned i; | |
625 | const deallocator *d; | |
626 | FOR_EACH_VEC_ELT (m_deallocator_vec, i, d) | |
627 | { | |
628 | if (i > 0) | |
629 | pp_string (pp, ", "); | |
630 | d->dump_to_pp (pp); | |
631 | } | |
632 | pp_character (pp, '}'); | |
633 | } | |
634 | ||
635 | /* struct standard_deallocator_set : public deallocator_set. */ | |
636 | ||
637 | standard_deallocator_set::standard_deallocator_set (malloc_state_machine *sm, | |
638 | const char *name, | |
639 | enum wording wording) | |
640 | : deallocator_set (sm, wording), | |
641 | m_deallocator (sm, name, wording) | |
642 | { | |
643 | } | |
644 | ||
645 | bool | |
646 | standard_deallocator_set::contains_p (const deallocator *d) const | |
647 | { | |
648 | return d == &m_deallocator; | |
649 | } | |
650 | ||
651 | const deallocator * | |
652 | standard_deallocator_set::maybe_get_single () const | |
653 | { | |
654 | return &m_deallocator; | |
655 | } | |
656 | ||
657 | void | |
658 | standard_deallocator_set::dump_to_pp (pretty_printer *pp) const | |
659 | { | |
660 | pp_character (pp, '{'); | |
661 | pp_string (pp, m_deallocator.m_name); | |
662 | pp_character (pp, '}'); | |
663 | } | |
664 | ||
1690a839 DM |
665 | /* Return STATE cast to the custom state subclass, or NULL for the start state. |
666 | Everything should be an allocation_state apart from the start state. */ | |
667 | ||
668 | static const allocation_state * | |
669 | dyn_cast_allocation_state (state_machine::state_t state) | |
670 | { | |
671 | if (state->get_id () == 0) | |
672 | return NULL; | |
673 | return static_cast <const allocation_state *> (state); | |
674 | } | |
675 | ||
676 | /* Return STATE cast to the custom state subclass, for a state that is | |
677 | already known to not be the start state . */ | |
678 | ||
679 | static const allocation_state * | |
680 | as_a_allocation_state (state_machine::state_t state) | |
681 | { | |
682 | gcc_assert (state->get_id () != 0); | |
683 | return static_cast <const allocation_state *> (state); | |
684 | } | |
685 | ||
686 | /* Get the resource_state for STATE. */ | |
687 | ||
688 | static enum resource_state | |
689 | get_rs (state_machine::state_t state) | |
690 | { | |
691 | if (const allocation_state *astate = dyn_cast_allocation_state (state)) | |
692 | return astate->m_rs; | |
693 | else | |
694 | return RS_START; | |
695 | } | |
696 | ||
c7e276b8 DM |
697 | /* Return true if STATE is the start state. */ |
698 | ||
699 | static bool | |
700 | start_p (state_machine::state_t state) | |
701 | { | |
702 | return get_rs (state) == RS_START; | |
703 | } | |
704 | ||
1690a839 DM |
705 | /* Return true if STATE is an unchecked result from an allocator. */ |
706 | ||
707 | static bool | |
708 | unchecked_p (state_machine::state_t state) | |
709 | { | |
710 | return get_rs (state) == RS_UNCHECKED; | |
711 | } | |
712 | ||
713 | /* Return true if STATE is a non-null result from an allocator. */ | |
714 | ||
715 | static bool | |
716 | nonnull_p (state_machine::state_t state) | |
717 | { | |
718 | return get_rs (state) == RS_NONNULL; | |
719 | } | |
720 | ||
721 | /* Return true if STATE is a value that has been passed to a deallocator. */ | |
722 | ||
723 | static bool | |
724 | freed_p (state_machine::state_t state) | |
725 | { | |
726 | return get_rs (state) == RS_FREED; | |
727 | } | |
728 | ||
5c6546ca DM |
729 | /* Return true if STATE is a value that has been assumed to be non-NULL. */ |
730 | ||
731 | static bool | |
732 | assumed_non_null_p (state_machine::state_t state) | |
733 | { | |
734 | return get_rs (state) == RS_ASSUMED_NON_NULL; | |
735 | } | |
736 | ||
757bf1df DM |
737 | /* Class for diagnostics relating to malloc_state_machine. */ |
738 | ||
739 | class malloc_diagnostic : public pending_diagnostic | |
740 | { | |
741 | public: | |
742 | malloc_diagnostic (const malloc_state_machine &sm, tree arg) | |
743 | : m_sm (sm), m_arg (arg) | |
744 | {} | |
745 | ||
ff171cb1 | 746 | bool subclass_equal_p (const pending_diagnostic &base_other) const override |
757bf1df | 747 | { |
14f9d7b9 | 748 | return same_tree_p (m_arg, ((const malloc_diagnostic &)base_other).m_arg); |
757bf1df DM |
749 | } |
750 | ||
751 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 752 | override |
757bf1df | 753 | { |
10fc42a8 | 754 | if (change.m_old_state == m_sm.get_start_state () |
1690a839 | 755 | && unchecked_p (change.m_new_state)) |
757bf1df DM |
756 | // TODO: verify that it's the allocation stmt, not a copy |
757 | return label_text::borrow ("allocated here"); | |
1690a839 DM |
758 | if (unchecked_p (change.m_old_state) |
759 | && nonnull_p (change.m_new_state)) | |
808f4dfe DM |
760 | { |
761 | if (change.m_expr) | |
762 | return change.formatted_print ("assuming %qE is non-NULL", | |
763 | change.m_expr); | |
764 | else | |
765 | return change.formatted_print ("assuming %qs is non-NULL", | |
766 | "<unknown>"); | |
767 | } | |
757bf1df | 768 | if (change.m_new_state == m_sm.m_null) |
0993ad65 | 769 | { |
1690a839 | 770 | if (unchecked_p (change.m_old_state)) |
808f4dfe DM |
771 | { |
772 | if (change.m_expr) | |
773 | return change.formatted_print ("assuming %qE is NULL", | |
774 | change.m_expr); | |
775 | else | |
776 | return change.formatted_print ("assuming %qs is NULL", | |
777 | "<unknown>"); | |
778 | } | |
0993ad65 | 779 | else |
808f4dfe DM |
780 | { |
781 | if (change.m_expr) | |
782 | return change.formatted_print ("%qE is NULL", | |
783 | change.m_expr); | |
784 | else | |
785 | return change.formatted_print ("%qs is NULL", | |
786 | "<unknown>"); | |
787 | } | |
0993ad65 DM |
788 | } |
789 | ||
757bf1df DM |
790 | return label_text (); |
791 | } | |
792 | ||
6cf276dd DM |
793 | diagnostic_event::meaning |
794 | get_meaning_for_state_change (const evdesc::state_change &change) | |
795 | const final override | |
796 | { | |
797 | if (change.m_old_state == m_sm.get_start_state () | |
798 | && unchecked_p (change.m_new_state)) | |
799 | return diagnostic_event::meaning (diagnostic_event::VERB_acquire, | |
800 | diagnostic_event::NOUN_memory); | |
801 | if (freed_p (change.m_new_state)) | |
802 | return diagnostic_event::meaning (diagnostic_event::VERB_release, | |
803 | diagnostic_event::NOUN_memory); | |
804 | return diagnostic_event::meaning (); | |
805 | } | |
806 | ||
757bf1df DM |
807 | protected: |
808 | const malloc_state_machine &m_sm; | |
809 | tree m_arg; | |
810 | }; | |
811 | ||
1690a839 DM |
812 | /* Concrete subclass for reporting mismatching allocator/deallocator |
813 | diagnostics. */ | |
814 | ||
815 | class mismatching_deallocation : public malloc_diagnostic | |
816 | { | |
817 | public: | |
818 | mismatching_deallocation (const malloc_state_machine &sm, tree arg, | |
c7e276b8 DM |
819 | const deallocator_set *expected_deallocators, |
820 | const deallocator *actual_dealloc) | |
1690a839 | 821 | : malloc_diagnostic (sm, arg), |
c7e276b8 | 822 | m_expected_deallocators (expected_deallocators), |
1690a839 DM |
823 | m_actual_dealloc (actual_dealloc) |
824 | {} | |
825 | ||
ff171cb1 | 826 | const char *get_kind () const final override |
1690a839 DM |
827 | { |
828 | return "mismatching_deallocation"; | |
829 | } | |
830 | ||
ff171cb1 | 831 | int get_controlling_option () const final override |
7fd6e36e DM |
832 | { |
833 | return OPT_Wanalyzer_mismatching_deallocation; | |
834 | } | |
835 | ||
ff171cb1 | 836 | bool emit (rich_location *rich_loc) final override |
1690a839 DM |
837 | { |
838 | auto_diagnostic_group d; | |
839 | diagnostic_metadata m; | |
840 | m.add_cwe (762); /* CWE-762: Mismatched Memory Management Routines. */ | |
c7e276b8 DM |
841 | if (const deallocator *expected_dealloc |
842 | = m_expected_deallocators->maybe_get_single ()) | |
7fd6e36e | 843 | return warning_meta (rich_loc, m, get_controlling_option (), |
c7e276b8 DM |
844 | "%qE should have been deallocated with %qs" |
845 | " but was deallocated with %qs", | |
846 | m_arg, expected_dealloc->m_name, | |
847 | m_actual_dealloc->m_name); | |
848 | else | |
7fd6e36e | 849 | return warning_meta (rich_loc, m, get_controlling_option (), |
c7e276b8 DM |
850 | "%qs called on %qE returned from a mismatched" |
851 | " allocation function", | |
852 | m_actual_dealloc->m_name, m_arg); | |
1690a839 DM |
853 | } |
854 | ||
855 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 856 | final override |
1690a839 DM |
857 | { |
858 | if (unchecked_p (change.m_new_state)) | |
859 | { | |
860 | m_alloc_event = change.m_event_id; | |
c7e276b8 DM |
861 | if (const deallocator *expected_dealloc |
862 | = m_expected_deallocators->maybe_get_single ()) | |
863 | return change.formatted_print ("allocated here" | |
864 | " (expects deallocation with %qs)", | |
865 | expected_dealloc->m_name); | |
866 | else | |
867 | return change.formatted_print ("allocated here"); | |
1690a839 DM |
868 | } |
869 | return malloc_diagnostic::describe_state_change (change); | |
870 | } | |
871 | ||
ff171cb1 | 872 | label_text describe_final_event (const evdesc::final_event &ev) final override |
1690a839 DM |
873 | { |
874 | if (m_alloc_event.known_p ()) | |
c7e276b8 DM |
875 | { |
876 | if (const deallocator *expected_dealloc | |
877 | = m_expected_deallocators->maybe_get_single ()) | |
878 | return ev.formatted_print | |
879 | ("deallocated with %qs here;" | |
880 | " allocation at %@ expects deallocation with %qs", | |
881 | m_actual_dealloc->m_name, &m_alloc_event, | |
882 | expected_dealloc->m_name); | |
883 | else | |
884 | return ev.formatted_print | |
885 | ("deallocated with %qs here;" | |
886 | " allocated at %@", | |
887 | m_actual_dealloc->m_name, &m_alloc_event); | |
888 | } | |
1690a839 | 889 | return ev.formatted_print ("deallocated with %qs here", |
c7e276b8 | 890 | m_actual_dealloc->m_name); |
1690a839 DM |
891 | } |
892 | ||
893 | private: | |
894 | diagnostic_event_id_t m_alloc_event; | |
c7e276b8 DM |
895 | const deallocator_set *m_expected_deallocators; |
896 | const deallocator *m_actual_dealloc; | |
1690a839 DM |
897 | }; |
898 | ||
757bf1df DM |
899 | /* Concrete subclass for reporting double-free diagnostics. */ |
900 | ||
901 | class double_free : public malloc_diagnostic | |
902 | { | |
903 | public: | |
1690a839 DM |
904 | double_free (const malloc_state_machine &sm, tree arg, const char *funcname) |
905 | : malloc_diagnostic (sm, arg), m_funcname (funcname) | |
757bf1df DM |
906 | {} |
907 | ||
ff171cb1 | 908 | const char *get_kind () const final override { return "double_free"; } |
757bf1df | 909 | |
ff171cb1 | 910 | int get_controlling_option () const final override |
7fd6e36e DM |
911 | { |
912 | return OPT_Wanalyzer_double_free; | |
913 | } | |
914 | ||
ff171cb1 | 915 | bool emit (rich_location *rich_loc) final override |
757bf1df DM |
916 | { |
917 | auto_diagnostic_group d; | |
918 | diagnostic_metadata m; | |
919 | m.add_cwe (415); /* CWE-415: Double Free. */ | |
7fd6e36e | 920 | return warning_meta (rich_loc, m, get_controlling_option (), |
c7e276b8 | 921 | "double-%qs of %qE", m_funcname, m_arg); |
757bf1df DM |
922 | } |
923 | ||
924 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 925 | final override |
757bf1df | 926 | { |
1690a839 | 927 | if (freed_p (change.m_new_state)) |
757bf1df DM |
928 | { |
929 | m_first_free_event = change.m_event_id; | |
1690a839 | 930 | return change.formatted_print ("first %qs here", m_funcname); |
757bf1df DM |
931 | } |
932 | return malloc_diagnostic::describe_state_change (change); | |
933 | } | |
934 | ||
935 | label_text describe_call_with_state (const evdesc::call_with_state &info) | |
ff171cb1 | 936 | final override |
757bf1df | 937 | { |
1690a839 | 938 | if (freed_p (info.m_state)) |
757bf1df DM |
939 | return info.formatted_print |
940 | ("passing freed pointer %qE in call to %qE from %qE", | |
941 | info.m_expr, info.m_callee_fndecl, info.m_caller_fndecl); | |
942 | return label_text (); | |
943 | } | |
944 | ||
ff171cb1 | 945 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df DM |
946 | { |
947 | if (m_first_free_event.known_p ()) | |
948 | return ev.formatted_print ("second %qs here; first %qs was at %@", | |
1690a839 | 949 | m_funcname, m_funcname, |
757bf1df | 950 | &m_first_free_event); |
1690a839 | 951 | return ev.formatted_print ("second %qs here", m_funcname); |
757bf1df DM |
952 | } |
953 | ||
954 | private: | |
955 | diagnostic_event_id_t m_first_free_event; | |
1690a839 | 956 | const char *m_funcname; |
757bf1df DM |
957 | }; |
958 | ||
959 | /* Abstract subclass for describing possible bad uses of NULL. | |
960 | Responsible for describing the call that could return NULL. */ | |
961 | ||
962 | class possible_null : public malloc_diagnostic | |
963 | { | |
964 | public: | |
965 | possible_null (const malloc_state_machine &sm, tree arg) | |
966 | : malloc_diagnostic (sm, arg) | |
967 | {} | |
968 | ||
969 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 970 | final override |
757bf1df | 971 | { |
10fc42a8 | 972 | if (change.m_old_state == m_sm.get_start_state () |
1690a839 | 973 | && unchecked_p (change.m_new_state)) |
757bf1df DM |
974 | { |
975 | m_origin_of_unchecked_event = change.m_event_id; | |
976 | return label_text::borrow ("this call could return NULL"); | |
977 | } | |
978 | return malloc_diagnostic::describe_state_change (change); | |
979 | } | |
980 | ||
981 | label_text describe_return_of_state (const evdesc::return_of_state &info) | |
ff171cb1 | 982 | final override |
757bf1df | 983 | { |
1690a839 | 984 | if (unchecked_p (info.m_state)) |
757bf1df DM |
985 | return info.formatted_print ("possible return of NULL to %qE from %qE", |
986 | info.m_caller_fndecl, info.m_callee_fndecl); | |
987 | return label_text (); | |
988 | } | |
989 | ||
990 | protected: | |
991 | diagnostic_event_id_t m_origin_of_unchecked_event; | |
992 | }; | |
993 | ||
994 | /* Concrete subclass for describing dereference of a possible NULL | |
995 | value. */ | |
996 | ||
997 | class possible_null_deref : public possible_null | |
998 | { | |
999 | public: | |
1000 | possible_null_deref (const malloc_state_machine &sm, tree arg) | |
1001 | : possible_null (sm, arg) | |
1002 | {} | |
1003 | ||
ff171cb1 | 1004 | const char *get_kind () const final override { return "possible_null_deref"; } |
757bf1df | 1005 | |
ff171cb1 | 1006 | int get_controlling_option () const final override |
7fd6e36e DM |
1007 | { |
1008 | return OPT_Wanalyzer_possible_null_dereference; | |
1009 | } | |
1010 | ||
ff171cb1 | 1011 | bool emit (rich_location *rich_loc) final override |
757bf1df DM |
1012 | { |
1013 | /* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */ | |
1014 | diagnostic_metadata m; | |
1015 | m.add_cwe (690); | |
7fd6e36e | 1016 | return warning_meta (rich_loc, m, get_controlling_option (), |
6c8e5844 | 1017 | "dereference of possibly-NULL %qE", m_arg); |
757bf1df DM |
1018 | } |
1019 | ||
ff171cb1 | 1020 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df DM |
1021 | { |
1022 | if (m_origin_of_unchecked_event.known_p ()) | |
1023 | return ev.formatted_print ("%qE could be NULL: unchecked value from %@", | |
1024 | ev.m_expr, | |
1025 | &m_origin_of_unchecked_event); | |
1026 | else | |
1027 | return ev.formatted_print ("%qE could be NULL", ev.m_expr); | |
1028 | } | |
1029 | ||
1030 | }; | |
1031 | ||
2f7c50b7 DM |
1032 | /* Return true if FNDECL is a C++ method. */ |
1033 | ||
1034 | static bool | |
1035 | method_p (tree fndecl) | |
1036 | { | |
1037 | return TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE; | |
1038 | } | |
1039 | ||
1040 | /* Return a 1-based description of ARG_IDX (0-based) of FNDECL. | |
e53b6e56 | 1041 | Compare with %P in the C++ FE (implemented in cp/error.cc: parm_to_string |
2f7c50b7 DM |
1042 | as called from cp_printer). */ |
1043 | ||
1044 | static label_text | |
1045 | describe_argument_index (tree fndecl, int arg_idx) | |
1046 | { | |
1047 | if (method_p (fndecl)) | |
1048 | if (arg_idx == 0) | |
1049 | return label_text::borrow ("'this'"); | |
1050 | pretty_printer pp; | |
1051 | pp_printf (&pp, "%u", arg_idx + 1 - method_p (fndecl)); | |
1052 | return label_text::take (xstrdup (pp_formatted_text (&pp))); | |
1053 | } | |
1054 | ||
757bf1df DM |
1055 | /* Subroutine for use by possible_null_arg::emit and null_arg::emit. |
1056 | Issue a note informing that the pertinent argument must be non-NULL. */ | |
1057 | ||
1058 | static void | |
1059 | inform_nonnull_attribute (tree fndecl, int arg_idx) | |
1060 | { | |
2f7c50b7 | 1061 | label_text arg_desc = describe_argument_index (fndecl, arg_idx); |
757bf1df | 1062 | inform (DECL_SOURCE_LOCATION (fndecl), |
2f7c50b7 | 1063 | "argument %s of %qD must be non-null", |
f858fe7a | 1064 | arg_desc.get (), fndecl); |
757bf1df DM |
1065 | /* Ideally we would use the location of the parm and underline the |
1066 | attribute also - but we don't have the location_t values at this point | |
1067 | in the middle-end. | |
1068 | For reference, the C and C++ FEs have get_fndecl_argument_location. */ | |
1069 | } | |
1070 | ||
1071 | /* Concrete subclass for describing passing a possibly-NULL value to a | |
1072 | function marked with __attribute__((nonnull)). */ | |
1073 | ||
1074 | class possible_null_arg : public possible_null | |
1075 | { | |
1076 | public: | |
1077 | possible_null_arg (const malloc_state_machine &sm, tree arg, | |
1078 | tree fndecl, int arg_idx) | |
1079 | : possible_null (sm, arg), | |
1080 | m_fndecl (fndecl), m_arg_idx (arg_idx) | |
1081 | {} | |
1082 | ||
ff171cb1 | 1083 | const char *get_kind () const final override { return "possible_null_arg"; } |
757bf1df | 1084 | |
2ac1459f DM |
1085 | bool subclass_equal_p (const pending_diagnostic &base_other) |
1086 | const final override | |
757bf1df DM |
1087 | { |
1088 | const possible_null_arg &sub_other | |
1089 | = (const possible_null_arg &)base_other; | |
14f9d7b9 | 1090 | return (same_tree_p (m_arg, sub_other.m_arg) |
757bf1df DM |
1091 | && m_fndecl == sub_other.m_fndecl |
1092 | && m_arg_idx == sub_other.m_arg_idx); | |
1093 | } | |
1094 | ||
ff171cb1 | 1095 | int get_controlling_option () const final override |
7fd6e36e DM |
1096 | { |
1097 | return OPT_Wanalyzer_possible_null_argument; | |
1098 | } | |
757bf1df | 1099 | |
ff171cb1 | 1100 | bool emit (rich_location *rich_loc) final override |
757bf1df DM |
1101 | { |
1102 | /* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */ | |
1103 | auto_diagnostic_group d; | |
1104 | diagnostic_metadata m; | |
1105 | m.add_cwe (690); | |
1106 | bool warned | |
7fd6e36e | 1107 | = warning_meta (rich_loc, m, get_controlling_option (), |
6c8e5844 DM |
1108 | "use of possibly-NULL %qE where non-null expected", |
1109 | m_arg); | |
757bf1df DM |
1110 | if (warned) |
1111 | inform_nonnull_attribute (m_fndecl, m_arg_idx); | |
1112 | return warned; | |
1113 | } | |
1114 | ||
ff171cb1 | 1115 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df | 1116 | { |
2f7c50b7 DM |
1117 | label_text arg_desc = describe_argument_index (m_fndecl, m_arg_idx); |
1118 | label_text result; | |
757bf1df | 1119 | if (m_origin_of_unchecked_event.known_p ()) |
2f7c50b7 DM |
1120 | result = ev.formatted_print ("argument %s (%qE) from %@ could be NULL" |
1121 | " where non-null expected", | |
f858fe7a | 1122 | arg_desc.get (), ev.m_expr, |
2f7c50b7 | 1123 | &m_origin_of_unchecked_event); |
757bf1df | 1124 | else |
2f7c50b7 DM |
1125 | result = ev.formatted_print ("argument %s (%qE) could be NULL" |
1126 | " where non-null expected", | |
f858fe7a | 1127 | arg_desc.get (), ev.m_expr); |
2f7c50b7 | 1128 | return result; |
757bf1df DM |
1129 | } |
1130 | ||
1131 | private: | |
1132 | tree m_fndecl; | |
1133 | int m_arg_idx; | |
1134 | }; | |
1135 | ||
1136 | /* Concrete subclass for describing a dereference of a NULL value. */ | |
1137 | ||
1138 | class null_deref : public malloc_diagnostic | |
1139 | { | |
1140 | public: | |
1141 | null_deref (const malloc_state_machine &sm, tree arg) | |
1142 | : malloc_diagnostic (sm, arg) {} | |
1143 | ||
ff171cb1 | 1144 | const char *get_kind () const final override { return "null_deref"; } |
757bf1df | 1145 | |
ff171cb1 | 1146 | int get_controlling_option () const final override |
7fd6e36e DM |
1147 | { |
1148 | return OPT_Wanalyzer_null_dereference; | |
1149 | } | |
1150 | ||
ff171cb1 | 1151 | bool emit (rich_location *rich_loc) final override |
757bf1df | 1152 | { |
f3f312b5 | 1153 | /* CWE-476: NULL Pointer Dereference. */ |
757bf1df | 1154 | diagnostic_metadata m; |
f3f312b5 | 1155 | m.add_cwe (476); |
7fd6e36e | 1156 | return warning_meta (rich_loc, m, get_controlling_option (), |
6c8e5844 | 1157 | "dereference of NULL %qE", m_arg); |
757bf1df DM |
1158 | } |
1159 | ||
1160 | label_text describe_return_of_state (const evdesc::return_of_state &info) | |
ff171cb1 | 1161 | final override |
757bf1df DM |
1162 | { |
1163 | if (info.m_state == m_sm.m_null) | |
1164 | return info.formatted_print ("return of NULL to %qE from %qE", | |
1165 | info.m_caller_fndecl, info.m_callee_fndecl); | |
1166 | return label_text (); | |
1167 | } | |
1168 | ||
ff171cb1 | 1169 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df DM |
1170 | { |
1171 | return ev.formatted_print ("dereference of NULL %qE", ev.m_expr); | |
1172 | } | |
1173 | }; | |
1174 | ||
1175 | /* Concrete subclass for describing passing a NULL value to a | |
1176 | function marked with __attribute__((nonnull)). */ | |
1177 | ||
1178 | class null_arg : public malloc_diagnostic | |
1179 | { | |
1180 | public: | |
1181 | null_arg (const malloc_state_machine &sm, tree arg, | |
1182 | tree fndecl, int arg_idx) | |
1183 | : malloc_diagnostic (sm, arg), | |
1184 | m_fndecl (fndecl), m_arg_idx (arg_idx) | |
1185 | {} | |
1186 | ||
ff171cb1 | 1187 | const char *get_kind () const final override { return "null_arg"; } |
757bf1df | 1188 | |
2ac1459f DM |
1189 | bool subclass_equal_p (const pending_diagnostic &base_other) |
1190 | const final override | |
757bf1df DM |
1191 | { |
1192 | const null_arg &sub_other | |
1193 | = (const null_arg &)base_other; | |
14f9d7b9 | 1194 | return (same_tree_p (m_arg, sub_other.m_arg) |
757bf1df DM |
1195 | && m_fndecl == sub_other.m_fndecl |
1196 | && m_arg_idx == sub_other.m_arg_idx); | |
1197 | } | |
1198 | ||
ff171cb1 | 1199 | int get_controlling_option () const final override |
7fd6e36e DM |
1200 | { |
1201 | return OPT_Wanalyzer_null_argument; | |
1202 | } | |
1203 | ||
ff171cb1 | 1204 | bool emit (rich_location *rich_loc) final override |
757bf1df | 1205 | { |
f3f312b5 | 1206 | /* CWE-476: NULL Pointer Dereference. */ |
757bf1df DM |
1207 | auto_diagnostic_group d; |
1208 | diagnostic_metadata m; | |
f3f312b5 | 1209 | m.add_cwe (476); |
808f4dfe DM |
1210 | |
1211 | bool warned; | |
1212 | if (zerop (m_arg)) | |
7fd6e36e | 1213 | warned = warning_meta (rich_loc, m, get_controlling_option (), |
808f4dfe DM |
1214 | "use of NULL where non-null expected"); |
1215 | else | |
7fd6e36e | 1216 | warned = warning_meta (rich_loc, m, get_controlling_option (), |
808f4dfe DM |
1217 | "use of NULL %qE where non-null expected", |
1218 | m_arg); | |
757bf1df DM |
1219 | if (warned) |
1220 | inform_nonnull_attribute (m_fndecl, m_arg_idx); | |
1221 | return warned; | |
1222 | } | |
1223 | ||
ff171cb1 | 1224 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df | 1225 | { |
2f7c50b7 DM |
1226 | label_text arg_desc = describe_argument_index (m_fndecl, m_arg_idx); |
1227 | label_text result; | |
808f4dfe | 1228 | if (zerop (ev.m_expr)) |
2f7c50b7 | 1229 | result = ev.formatted_print ("argument %s NULL where non-null expected", |
f858fe7a | 1230 | arg_desc.get ()); |
808f4dfe | 1231 | else |
2f7c50b7 DM |
1232 | result = ev.formatted_print ("argument %s (%qE) NULL" |
1233 | " where non-null expected", | |
f858fe7a | 1234 | arg_desc.get (), ev.m_expr); |
2f7c50b7 | 1235 | return result; |
757bf1df DM |
1236 | } |
1237 | ||
1238 | private: | |
1239 | tree m_fndecl; | |
1240 | int m_arg_idx; | |
1241 | }; | |
1242 | ||
1243 | class use_after_free : public malloc_diagnostic | |
1244 | { | |
1245 | public: | |
1690a839 | 1246 | use_after_free (const malloc_state_machine &sm, tree arg, |
c7e276b8 DM |
1247 | const deallocator *deallocator) |
1248 | : malloc_diagnostic (sm, arg), | |
1249 | m_deallocator (deallocator) | |
1250 | { | |
1251 | gcc_assert (deallocator); | |
1252 | } | |
757bf1df | 1253 | |
ff171cb1 | 1254 | const char *get_kind () const final override { return "use_after_free"; } |
757bf1df | 1255 | |
ff171cb1 | 1256 | int get_controlling_option () const final override |
7fd6e36e DM |
1257 | { |
1258 | return OPT_Wanalyzer_use_after_free; | |
1259 | } | |
1260 | ||
ff171cb1 | 1261 | bool emit (rich_location *rich_loc) final override |
757bf1df DM |
1262 | { |
1263 | /* CWE-416: Use After Free. */ | |
1264 | diagnostic_metadata m; | |
1265 | m.add_cwe (416); | |
7fd6e36e | 1266 | return warning_meta (rich_loc, m, get_controlling_option (), |
1690a839 | 1267 | "use after %<%s%> of %qE", |
c7e276b8 | 1268 | m_deallocator->m_name, m_arg); |
757bf1df DM |
1269 | } |
1270 | ||
1271 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 1272 | final override |
757bf1df | 1273 | { |
1690a839 | 1274 | if (freed_p (change.m_new_state)) |
757bf1df DM |
1275 | { |
1276 | m_free_event = change.m_event_id; | |
c7e276b8 | 1277 | switch (m_deallocator->m_wording) |
1690a839 DM |
1278 | { |
1279 | default: | |
a6baafca | 1280 | case WORDING_REALLOCATED: |
1690a839 DM |
1281 | gcc_unreachable (); |
1282 | case WORDING_FREED: | |
1283 | return label_text::borrow ("freed here"); | |
1284 | case WORDING_DELETED: | |
1285 | return label_text::borrow ("deleted here"); | |
c7e276b8 DM |
1286 | case WORDING_DEALLOCATED: |
1287 | return label_text::borrow ("deallocated here"); | |
1690a839 | 1288 | } |
757bf1df DM |
1289 | } |
1290 | return malloc_diagnostic::describe_state_change (change); | |
1291 | } | |
1292 | ||
ff171cb1 | 1293 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df | 1294 | { |
c7e276b8 | 1295 | const char *funcname = m_deallocator->m_name; |
757bf1df | 1296 | if (m_free_event.known_p ()) |
c7e276b8 | 1297 | switch (m_deallocator->m_wording) |
1690a839 DM |
1298 | { |
1299 | default: | |
a6baafca | 1300 | case WORDING_REALLOCATED: |
1690a839 DM |
1301 | gcc_unreachable (); |
1302 | case WORDING_FREED: | |
1303 | return ev.formatted_print ("use after %<%s%> of %qE; freed at %@", | |
1304 | funcname, ev.m_expr, &m_free_event); | |
1305 | case WORDING_DELETED: | |
1306 | return ev.formatted_print ("use after %<%s%> of %qE; deleted at %@", | |
1307 | funcname, ev.m_expr, &m_free_event); | |
c7e276b8 DM |
1308 | case WORDING_DEALLOCATED: |
1309 | return ev.formatted_print ("use after %<%s%> of %qE;" | |
1310 | " deallocated at %@", | |
1311 | funcname, ev.m_expr, &m_free_event); | |
1690a839 | 1312 | } |
757bf1df | 1313 | else |
1690a839 DM |
1314 | return ev.formatted_print ("use after %<%s%> of %qE", |
1315 | funcname, ev.m_expr); | |
757bf1df DM |
1316 | } |
1317 | ||
33255ad3 DM |
1318 | /* Implementation of pending_diagnostic::supercedes_p for |
1319 | use_after_free. | |
1320 | ||
1321 | We want use-after-free to supercede use-of-unitialized-value, | |
1322 | so that if we have these at the same stmt, we don't emit | |
1323 | a use-of-uninitialized, just the use-after-free. | |
1324 | (this is because we fully purge information about freed | |
1325 | buffers when we free them to avoid state explosions, so | |
1326 | that if they are accessed after the free, it looks like | |
1327 | they are uninitialized). */ | |
1328 | ||
ff171cb1 | 1329 | bool supercedes_p (const pending_diagnostic &other) const final override |
33255ad3 DM |
1330 | { |
1331 | if (other.use_of_uninit_p ()) | |
1332 | return true; | |
1333 | ||
1334 | return false; | |
1335 | } | |
1336 | ||
757bf1df DM |
1337 | private: |
1338 | diagnostic_event_id_t m_free_event; | |
c7e276b8 | 1339 | const deallocator *m_deallocator; |
757bf1df DM |
1340 | }; |
1341 | ||
1342 | class malloc_leak : public malloc_diagnostic | |
1343 | { | |
1344 | public: | |
1345 | malloc_leak (const malloc_state_machine &sm, tree arg) | |
1346 | : malloc_diagnostic (sm, arg) {} | |
1347 | ||
ff171cb1 | 1348 | const char *get_kind () const final override { return "malloc_leak"; } |
757bf1df | 1349 | |
ff171cb1 | 1350 | int get_controlling_option () const final override |
7fd6e36e DM |
1351 | { |
1352 | return OPT_Wanalyzer_malloc_leak; | |
1353 | } | |
1354 | ||
ff171cb1 | 1355 | bool emit (rich_location *rich_loc) final override |
757bf1df | 1356 | { |
9c603380 | 1357 | /* "CWE-401: Missing Release of Memory after Effective Lifetime". */ |
757bf1df DM |
1358 | diagnostic_metadata m; |
1359 | m.add_cwe (401); | |
808f4dfe | 1360 | if (m_arg) |
7fd6e36e | 1361 | return warning_meta (rich_loc, m, get_controlling_option (), |
808f4dfe DM |
1362 | "leak of %qE", m_arg); |
1363 | else | |
7fd6e36e | 1364 | return warning_meta (rich_loc, m, get_controlling_option (), |
808f4dfe | 1365 | "leak of %qs", "<unknown>"); |
757bf1df DM |
1366 | } |
1367 | ||
1368 | label_text describe_state_change (const evdesc::state_change &change) | |
ff171cb1 | 1369 | final override |
757bf1df | 1370 | { |
c7e276b8 DM |
1371 | if (unchecked_p (change.m_new_state) |
1372 | || (start_p (change.m_old_state) && nonnull_p (change.m_new_state))) | |
757bf1df | 1373 | { |
1690a839 | 1374 | m_alloc_event = change.m_event_id; |
757bf1df DM |
1375 | return label_text::borrow ("allocated here"); |
1376 | } | |
1377 | return malloc_diagnostic::describe_state_change (change); | |
1378 | } | |
1379 | ||
ff171cb1 | 1380 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df | 1381 | { |
808f4dfe DM |
1382 | if (ev.m_expr) |
1383 | { | |
1690a839 | 1384 | if (m_alloc_event.known_p ()) |
808f4dfe | 1385 | return ev.formatted_print ("%qE leaks here; was allocated at %@", |
1690a839 | 1386 | ev.m_expr, &m_alloc_event); |
808f4dfe DM |
1387 | else |
1388 | return ev.formatted_print ("%qE leaks here", ev.m_expr); | |
1389 | } | |
757bf1df | 1390 | else |
808f4dfe | 1391 | { |
1690a839 | 1392 | if (m_alloc_event.known_p ()) |
808f4dfe | 1393 | return ev.formatted_print ("%qs leaks here; was allocated at %@", |
1690a839 | 1394 | "<unknown>", &m_alloc_event); |
808f4dfe DM |
1395 | else |
1396 | return ev.formatted_print ("%qs leaks here", "<unknown>"); | |
1397 | } | |
757bf1df DM |
1398 | } |
1399 | ||
1400 | private: | |
1690a839 | 1401 | diagnostic_event_id_t m_alloc_event; |
757bf1df DM |
1402 | }; |
1403 | ||
1404 | class free_of_non_heap : public malloc_diagnostic | |
1405 | { | |
1406 | public: | |
1690a839 | 1407 | free_of_non_heap (const malloc_state_machine &sm, tree arg, |
a61aaee6 | 1408 | const region *freed_reg, |
1690a839 | 1409 | const char *funcname) |
a61aaee6 | 1410 | : malloc_diagnostic (sm, arg), m_freed_reg (freed_reg), m_funcname (funcname) |
757bf1df DM |
1411 | { |
1412 | } | |
1413 | ||
ff171cb1 | 1414 | const char *get_kind () const final override { return "free_of_non_heap"; } |
757bf1df DM |
1415 | |
1416 | bool subclass_equal_p (const pending_diagnostic &base_other) const | |
ff171cb1 | 1417 | final override |
757bf1df DM |
1418 | { |
1419 | const free_of_non_heap &other = (const free_of_non_heap &)base_other; | |
a61aaee6 DM |
1420 | return (same_tree_p (m_arg, other.m_arg) |
1421 | && m_freed_reg == other.m_freed_reg); | |
757bf1df DM |
1422 | } |
1423 | ||
ff171cb1 | 1424 | int get_controlling_option () const final override |
7fd6e36e DM |
1425 | { |
1426 | return OPT_Wanalyzer_free_of_non_heap; | |
1427 | } | |
1428 | ||
ff171cb1 | 1429 | bool emit (rich_location *rich_loc) final override |
757bf1df DM |
1430 | { |
1431 | auto_diagnostic_group d; | |
1432 | diagnostic_metadata m; | |
1433 | m.add_cwe (590); /* CWE-590: Free of Memory not on the Heap. */ | |
a61aaee6 | 1434 | switch (get_memory_space ()) |
757bf1df DM |
1435 | { |
1436 | default: | |
a61aaee6 | 1437 | case MEMSPACE_HEAP: |
757bf1df | 1438 | gcc_unreachable (); |
a61aaee6 DM |
1439 | case MEMSPACE_UNKNOWN: |
1440 | case MEMSPACE_CODE: | |
1441 | case MEMSPACE_GLOBALS: | |
1442 | case MEMSPACE_READONLY_DATA: | |
7fd6e36e | 1443 | return warning_meta (rich_loc, m, get_controlling_option (), |
1690a839 | 1444 | "%<%s%> of %qE which points to memory" |
6c8e5844 | 1445 | " not on the heap", |
1690a839 | 1446 | m_funcname, m_arg); |
757bf1df | 1447 | break; |
a61aaee6 | 1448 | case MEMSPACE_STACK: |
7fd6e36e | 1449 | return warning_meta (rich_loc, m, get_controlling_option (), |
a61aaee6 DM |
1450 | "%<%s%> of %qE which points to memory" |
1451 | " on the stack", | |
1452 | m_funcname, m_arg); | |
757bf1df DM |
1453 | break; |
1454 | } | |
1455 | } | |
1456 | ||
a61aaee6 | 1457 | label_text describe_state_change (const evdesc::state_change &) |
ff171cb1 | 1458 | final override |
757bf1df | 1459 | { |
757bf1df DM |
1460 | return label_text::borrow ("pointer is from here"); |
1461 | } | |
1462 | ||
ff171cb1 | 1463 | label_text describe_final_event (const evdesc::final_event &ev) final override |
757bf1df | 1464 | { |
1690a839 | 1465 | return ev.formatted_print ("call to %qs here", m_funcname); |
757bf1df DM |
1466 | } |
1467 | ||
ff171cb1 | 1468 | void mark_interesting_stuff (interesting_t *interest) final override |
a61aaee6 DM |
1469 | { |
1470 | if (m_freed_reg) | |
1471 | interest->add_region_creation (m_freed_reg); | |
1472 | } | |
1473 | ||
757bf1df | 1474 | private: |
a61aaee6 | 1475 | enum memory_space get_memory_space () const |
757bf1df | 1476 | { |
a61aaee6 DM |
1477 | if (m_freed_reg) |
1478 | return m_freed_reg->get_memory_space (); | |
1479 | else | |
1480 | return MEMSPACE_UNKNOWN; | |
1481 | } | |
1482 | ||
1483 | const region *m_freed_reg; | |
1690a839 | 1484 | const char *m_funcname; |
757bf1df DM |
1485 | }; |
1486 | ||
5c6546ca DM |
1487 | /* Concrete pending_diagnostic subclass for -Wanalyzer-deref-before-check. */ |
1488 | ||
1489 | class deref_before_check : public malloc_diagnostic | |
1490 | { | |
1491 | public: | |
1492 | deref_before_check (const malloc_state_machine &sm, tree arg) | |
1493 | : malloc_diagnostic (sm, arg) | |
1494 | {} | |
1495 | ||
1496 | const char *get_kind () const final override { return "deref_before_check"; } | |
1497 | ||
1498 | int get_controlling_option () const final override | |
1499 | { | |
1500 | return OPT_Wanalyzer_deref_before_check; | |
1501 | } | |
1502 | ||
1503 | bool emit (rich_location *rich_loc) final override | |
1504 | { | |
1505 | if (m_arg) | |
1506 | return warning_at (rich_loc, get_controlling_option (), | |
1507 | "check of %qE for NULL after already" | |
1508 | " dereferencing it", | |
1509 | m_arg); | |
1510 | else | |
1511 | return warning_at (rich_loc, get_controlling_option (), | |
1512 | "check of pointer for NULL after already" | |
1513 | " dereferencing it"); | |
1514 | } | |
1515 | ||
1516 | label_text describe_state_change (const evdesc::state_change &change) | |
1517 | final override | |
1518 | { | |
1519 | if (change.m_old_state == m_sm.get_start_state () | |
1520 | && assumed_non_null_p (change.m_new_state)) | |
1521 | { | |
1522 | m_first_deref_event = change.m_event_id; | |
1523 | if (m_arg) | |
1524 | return change.formatted_print ("pointer %qE is dereferenced here", | |
1525 | m_arg); | |
1526 | else | |
1527 | return label_text::borrow ("pointer is dereferenced here"); | |
1528 | } | |
1529 | return malloc_diagnostic::describe_state_change (change); | |
1530 | } | |
1531 | ||
1532 | label_text describe_final_event (const evdesc::final_event &ev) final override | |
1533 | { | |
1534 | if (m_first_deref_event.known_p ()) | |
1535 | { | |
1536 | if (m_arg) | |
1537 | return ev.formatted_print ("pointer %qE is checked for NULL here but" | |
1538 | " it was already dereferenced at %@", | |
1539 | m_arg, &m_first_deref_event); | |
1540 | else | |
1541 | return ev.formatted_print ("pointer is checked for NULL here but" | |
1542 | " it was already dereferenced at %@", | |
1543 | &m_first_deref_event); | |
1544 | } | |
1545 | else | |
1546 | { | |
1547 | if (m_arg) | |
1548 | return ev.formatted_print ("pointer %qE is checked for NULL here but" | |
1549 | " it was already dereferenced", | |
1550 | m_arg); | |
1551 | else | |
1552 | return ev.formatted_print ("pointer is checked for NULL here but" | |
1553 | " it was already dereferenced"); | |
1554 | } | |
1555 | } | |
1556 | ||
1557 | private: | |
1558 | diagnostic_event_id_t m_first_deref_event; | |
1559 | }; | |
1560 | ||
1690a839 DM |
1561 | /* struct allocation_state : public state_machine::state. */ |
1562 | ||
1563 | /* Implementation of state_machine::state::dump_to_pp vfunc | |
1564 | for allocation_state: append the API that this allocation is | |
1565 | associated with. */ | |
1566 | ||
1567 | void | |
1568 | allocation_state::dump_to_pp (pretty_printer *pp) const | |
1569 | { | |
1570 | state_machine::state::dump_to_pp (pp); | |
c7e276b8 DM |
1571 | if (m_deallocators) |
1572 | { | |
1573 | pp_string (pp, " ("); | |
1574 | m_deallocators->dump_to_pp (pp); | |
1575 | pp_character (pp, ')'); | |
1576 | } | |
1690a839 DM |
1577 | } |
1578 | ||
c7e276b8 DM |
1579 | /* Given a allocation_state for a deallocator_set, get the "nonnull" state |
1580 | for the corresponding allocator(s). */ | |
1690a839 DM |
1581 | |
1582 | const allocation_state * | |
1583 | allocation_state::get_nonnull () const | |
1584 | { | |
c7e276b8 DM |
1585 | gcc_assert (m_deallocators); |
1586 | return as_a_allocation_state (m_deallocators->m_nonnull); | |
1690a839 DM |
1587 | } |
1588 | ||
5c6546ca DM |
1589 | /* struct assumed_non_null_state : public allocation_state. */ |
1590 | ||
1591 | void | |
1592 | assumed_non_null_state::dump_to_pp (pretty_printer *pp) const | |
1593 | { | |
1594 | allocation_state::dump_to_pp (pp); | |
1595 | pp_string (pp, " (in "); | |
1596 | m_frame->dump_to_pp (pp, true); | |
1597 | pp_character (pp, ')'); | |
1598 | } | |
1599 | ||
757bf1df DM |
1600 | /* malloc_state_machine's ctor. */ |
1601 | ||
1602 | malloc_state_machine::malloc_state_machine (logger *logger) | |
1690a839 | 1603 | : state_machine ("malloc", logger), |
c7e276b8 DM |
1604 | m_free (this, "free", WORDING_FREED), |
1605 | m_scalar_delete (this, "delete", WORDING_DELETED), | |
a6baafca DM |
1606 | m_vector_delete (this, "delete[]", WORDING_DELETED), |
1607 | m_realloc (this, "realloc", WORDING_REALLOCATED) | |
1690a839 DM |
1608 | { |
1609 | gcc_assert (m_start->get_id () == 0); | |
c7e276b8 DM |
1610 | m_null = add_state ("null", RS_FREED, NULL, NULL); |
1611 | m_non_heap = add_state ("non-heap", RS_NON_HEAP, NULL, NULL); | |
1612 | m_stop = add_state ("stop", RS_STOP, NULL, NULL); | |
1613 | } | |
1614 | ||
1615 | malloc_state_machine::~malloc_state_machine () | |
1616 | { | |
1617 | unsigned i; | |
1618 | custom_deallocator_set *set; | |
1619 | FOR_EACH_VEC_ELT (m_dynamic_sets, i, set) | |
1620 | delete set; | |
1621 | custom_deallocator *d; | |
1622 | FOR_EACH_VEC_ELT (m_dynamic_deallocators, i, d) | |
1623 | delete d; | |
1690a839 DM |
1624 | } |
1625 | ||
1626 | state_machine::state_t | |
1627 | malloc_state_machine::add_state (const char *name, enum resource_state rs, | |
c7e276b8 DM |
1628 | const deallocator_set *deallocators, |
1629 | const deallocator *deallocator) | |
1690a839 DM |
1630 | { |
1631 | return add_custom_state (new allocation_state (name, alloc_state_id (), | |
c7e276b8 DM |
1632 | rs, deallocators, |
1633 | deallocator)); | |
1634 | } | |
1635 | ||
1636 | /* If ALLOCATOR_FNDECL has any "__attribute__((malloc(FOO)))", | |
1637 | return a custom_deallocator_set for them, consolidating them | |
1638 | to ensure uniqueness of the sets. | |
1639 | ||
1640 | Return NULL if it has no such attributes. */ | |
1641 | ||
1642 | const custom_deallocator_set * | |
1643 | malloc_state_machine:: | |
1644 | get_or_create_custom_deallocator_set (tree allocator_fndecl) | |
1645 | { | |
1646 | /* Early rejection of decls without attributes. */ | |
1647 | tree attrs = DECL_ATTRIBUTES (allocator_fndecl); | |
1648 | if (!attrs) | |
1649 | return NULL; | |
1650 | ||
1651 | /* Otherwise, call maybe_create_custom_deallocator_set, | |
1652 | memoizing the result. */ | |
1653 | if (custom_deallocator_set **slot | |
1654 | = m_custom_deallocator_set_cache.get (allocator_fndecl)) | |
1655 | return *slot; | |
1656 | custom_deallocator_set *set | |
1657 | = maybe_create_custom_deallocator_set (allocator_fndecl); | |
1658 | m_custom_deallocator_set_cache.put (allocator_fndecl, set); | |
1659 | return set; | |
1660 | } | |
1661 | ||
1662 | /* Given ALLOCATOR_FNDECL, a FUNCTION_DECL with attributes, | |
1663 | look for any "__attribute__((malloc(FOO)))" and return a | |
1664 | custom_deallocator_set for them, consolidating them | |
1665 | to ensure uniqueness of the sets. | |
1666 | ||
1667 | Return NULL if it has no such attributes. | |
1668 | ||
1669 | Subroutine of get_or_create_custom_deallocator_set which | |
1670 | memoizes the result. */ | |
1671 | ||
1672 | custom_deallocator_set * | |
1673 | malloc_state_machine:: | |
1674 | maybe_create_custom_deallocator_set (tree allocator_fndecl) | |
1675 | { | |
1676 | tree attrs = DECL_ATTRIBUTES (allocator_fndecl); | |
1677 | gcc_assert (attrs); | |
1678 | ||
1679 | /* Look for instances of __attribute__((malloc(FOO))). */ | |
1680 | auto_vec<const deallocator *> deallocator_vec; | |
1681 | for (tree allocs = attrs; | |
1682 | (allocs = lookup_attribute ("malloc", allocs)); | |
1683 | allocs = TREE_CHAIN (allocs)) | |
1684 | { | |
1685 | tree args = TREE_VALUE (allocs); | |
1686 | if (!args) | |
1687 | continue; | |
1688 | if (TREE_VALUE (args)) | |
1689 | { | |
1690 | const deallocator *d | |
1691 | = get_or_create_deallocator (TREE_VALUE (args)); | |
1692 | deallocator_vec.safe_push (d); | |
1693 | } | |
1694 | } | |
1695 | ||
1696 | /* If there weren't any deallocators, bail. */ | |
1697 | if (deallocator_vec.length () == 0) | |
1698 | return NULL; | |
1699 | ||
1700 | /* Consolidate, so that we reuse existing deallocator_set | |
1701 | instances. */ | |
1702 | deallocator_vec.qsort (deallocator::cmp_ptr_ptr); | |
1703 | custom_deallocator_set **slot | |
1704 | = m_custom_deallocator_set_map.get (&deallocator_vec); | |
1705 | if (slot) | |
1706 | return *slot; | |
1707 | custom_deallocator_set *set | |
1708 | = new custom_deallocator_set (this, &deallocator_vec, WORDING_DEALLOCATED); | |
1709 | m_custom_deallocator_set_map.put (&set->m_deallocator_vec, set); | |
1710 | m_dynamic_sets.safe_push (set); | |
1711 | return set; | |
1712 | } | |
1713 | ||
1714 | /* Get the deallocator for DEALLOCATOR_FNDECL, creating it if necessary. */ | |
1715 | ||
1716 | const deallocator * | |
1717 | malloc_state_machine::get_or_create_deallocator (tree deallocator_fndecl) | |
1718 | { | |
1719 | deallocator **slot = m_deallocator_map.get (deallocator_fndecl); | |
1720 | if (slot) | |
1721 | return *slot; | |
1722 | ||
1723 | /* Reuse "free". */ | |
1724 | deallocator *d; | |
1725 | if (is_named_call_p (deallocator_fndecl, "free") | |
84606efb SP |
1726 | || is_std_named_call_p (deallocator_fndecl, "free") |
1727 | || is_named_call_p (deallocator_fndecl, "__builtin_free")) | |
c7e276b8 DM |
1728 | d = &m_free.m_deallocator; |
1729 | else | |
1730 | { | |
1731 | custom_deallocator *cd | |
1732 | = new custom_deallocator (this, deallocator_fndecl, | |
1733 | WORDING_DEALLOCATED); | |
1734 | m_dynamic_deallocators.safe_push (cd); | |
1735 | d = cd; | |
1736 | } | |
1737 | m_deallocator_map.put (deallocator_fndecl, d); | |
1738 | return d; | |
757bf1df DM |
1739 | } |
1740 | ||
5c6546ca DM |
1741 | /* Get the "assumed-non-null" state for assumptions made within FRAME, |
1742 | creating it if necessary. */ | |
1743 | ||
1744 | state_machine::state_t | |
1745 | malloc_state_machine:: | |
1746 | get_or_create_assumed_non_null_state_for_frame (const frame_region *frame) | |
1747 | { | |
1748 | if (state_t *slot = m_assumed_non_null.get (frame)) | |
1749 | return *slot; | |
1750 | state_machine::state *new_state | |
1751 | = new assumed_non_null_state ("assumed-non-null", alloc_state_id (), frame); | |
1752 | add_custom_state (new_state); | |
1753 | m_assumed_non_null.put (frame, new_state); | |
1754 | return new_state; | |
1755 | } | |
1756 | ||
31534ac2 SP |
1757 | /* Try to identify the function declaration either by name or as a known malloc |
1758 | builtin. */ | |
1759 | ||
1760 | static bool | |
1761 | known_allocator_p (const_tree fndecl, const gcall *call) | |
1762 | { | |
1763 | /* Either it is a function we know by name and number of arguments... */ | |
1764 | if (is_named_call_p (fndecl, "malloc", call, 1) | |
1765 | || is_named_call_p (fndecl, "calloc", call, 2) | |
1766 | || is_std_named_call_p (fndecl, "malloc", call, 1) | |
1767 | || is_std_named_call_p (fndecl, "calloc", call, 2) | |
1768 | || is_named_call_p (fndecl, "strdup", call, 1) | |
1769 | || is_named_call_p (fndecl, "strndup", call, 2)) | |
1770 | return true; | |
1771 | ||
1772 | /* ... or it is a builtin allocator that allocates objects freed with | |
1773 | __builtin_free. */ | |
1a830c06 | 1774 | if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) |
31534ac2 SP |
1775 | switch (DECL_FUNCTION_CODE (fndecl)) |
1776 | { | |
1777 | case BUILT_IN_MALLOC: | |
1778 | case BUILT_IN_CALLOC: | |
1779 | case BUILT_IN_STRDUP: | |
1780 | case BUILT_IN_STRNDUP: | |
1781 | return true; | |
1782 | default: | |
1783 | break; | |
1784 | } | |
1785 | ||
1786 | return false; | |
1787 | } | |
1788 | ||
5c6546ca DM |
1789 | /* If PTR's nullness is not known, transition it to the "assumed-non-null" |
1790 | state for the current frame. */ | |
1791 | ||
1792 | void | |
1793 | malloc_state_machine::maybe_assume_non_null (sm_context *sm_ctxt, | |
1794 | tree ptr, | |
1795 | const gimple *stmt) const | |
1796 | { | |
1797 | const region_model *old_model = sm_ctxt->get_old_region_model (); | |
1798 | if (!old_model) | |
1799 | return; | |
1800 | ||
1801 | tree null_ptr_cst = build_int_cst (TREE_TYPE (ptr), 0); | |
1802 | tristate known_non_null | |
1803 | = old_model->eval_condition (ptr, NE_EXPR, null_ptr_cst, NULL); | |
1804 | if (known_non_null.is_unknown ()) | |
1805 | { | |
1806 | /* Cast away const-ness for cache-like operations. */ | |
1807 | malloc_state_machine *mut_this | |
1808 | = const_cast <malloc_state_machine *> (this); | |
1809 | state_t next_state | |
1810 | = mut_this->get_or_create_assumed_non_null_state_for_frame | |
1811 | (old_model->get_current_frame ()); | |
1812 | sm_ctxt->set_next_state (stmt, ptr, next_state); | |
1813 | } | |
1814 | } | |
1815 | ||
757bf1df DM |
1816 | /* Implementation of state_machine::on_stmt vfunc for malloc_state_machine. */ |
1817 | ||
1818 | bool | |
1819 | malloc_state_machine::on_stmt (sm_context *sm_ctxt, | |
1820 | const supernode *node, | |
1821 | const gimple *stmt) const | |
1822 | { | |
1823 | if (const gcall *call = dyn_cast <const gcall *> (stmt)) | |
1824 | if (tree callee_fndecl = sm_ctxt->get_fndecl_for_call (call)) | |
1825 | { | |
31534ac2 | 1826 | if (known_allocator_p (callee_fndecl, call)) |
757bf1df | 1827 | { |
c7e276b8 | 1828 | on_allocator_call (sm_ctxt, call, &m_free); |
1690a839 DM |
1829 | return true; |
1830 | } | |
1831 | ||
1832 | if (is_named_call_p (callee_fndecl, "operator new", call, 1)) | |
c7e276b8 | 1833 | on_allocator_call (sm_ctxt, call, &m_scalar_delete); |
1690a839 | 1834 | else if (is_named_call_p (callee_fndecl, "operator new []", call, 1)) |
c7e276b8 | 1835 | on_allocator_call (sm_ctxt, call, &m_vector_delete); |
1690a839 DM |
1836 | else if (is_named_call_p (callee_fndecl, "operator delete", call, 1) |
1837 | || is_named_call_p (callee_fndecl, "operator delete", call, 2)) | |
1838 | { | |
c7e276b8 DM |
1839 | on_deallocator_call (sm_ctxt, node, call, |
1840 | &m_scalar_delete.m_deallocator, 0); | |
1690a839 DM |
1841 | return true; |
1842 | } | |
1843 | else if (is_named_call_p (callee_fndecl, "operator delete []", call, 1)) | |
1844 | { | |
c7e276b8 DM |
1845 | on_deallocator_call (sm_ctxt, node, call, |
1846 | &m_vector_delete.m_deallocator, 0); | |
757bf1df DM |
1847 | return true; |
1848 | } | |
1849 | ||
1850 | if (is_named_call_p (callee_fndecl, "alloca", call, 1) | |
1851 | || is_named_call_p (callee_fndecl, "__builtin_alloca", call, 1)) | |
1852 | { | |
1853 | tree lhs = gimple_call_lhs (call); | |
1854 | if (lhs) | |
808f4dfe | 1855 | sm_ctxt->on_transition (node, stmt, lhs, m_start, m_non_heap); |
757bf1df DM |
1856 | return true; |
1857 | } | |
1858 | ||
1859 | if (is_named_call_p (callee_fndecl, "free", call, 1) | |
9f00b22f | 1860 | || is_std_named_call_p (callee_fndecl, "free", call, 1) |
757bf1df DM |
1861 | || is_named_call_p (callee_fndecl, "__builtin_free", call, 1)) |
1862 | { | |
c7e276b8 DM |
1863 | on_deallocator_call (sm_ctxt, node, call, |
1864 | &m_free.m_deallocator, 0); | |
757bf1df DM |
1865 | return true; |
1866 | } | |
1867 | ||
a6baafca DM |
1868 | if (is_named_call_p (callee_fndecl, "realloc", call, 2) |
1869 | || is_named_call_p (callee_fndecl, "__builtin_realloc", call, 2)) | |
1870 | { | |
1871 | on_realloc_call (sm_ctxt, node, call); | |
1872 | return true; | |
1873 | } | |
1874 | ||
cd323d97 DM |
1875 | if (unaffected_by_call_p (callee_fndecl)) |
1876 | return true; | |
1877 | ||
c7e276b8 DM |
1878 | /* Cast away const-ness for cache-like operations. */ |
1879 | malloc_state_machine *mutable_this | |
1880 | = const_cast <malloc_state_machine *> (this); | |
1881 | ||
1882 | /* Handle "__attribute__((malloc(FOO)))". */ | |
1883 | if (const deallocator_set *deallocators | |
1884 | = mutable_this->get_or_create_custom_deallocator_set | |
1885 | (callee_fndecl)) | |
1886 | { | |
1887 | tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (callee_fndecl)); | |
1888 | bool returns_nonnull | |
1889 | = lookup_attribute ("returns_nonnull", attrs); | |
1890 | on_allocator_call (sm_ctxt, call, deallocators, returns_nonnull); | |
1891 | } | |
1892 | ||
757bf1df DM |
1893 | /* Handle "__attribute__((nonnull))". */ |
1894 | { | |
1895 | tree fntype = TREE_TYPE (callee_fndecl); | |
1896 | bitmap nonnull_args = get_nonnull_args (fntype); | |
1897 | if (nonnull_args) | |
1898 | { | |
1899 | for (unsigned i = 0; i < gimple_call_num_args (stmt); i++) | |
1900 | { | |
1901 | tree arg = gimple_call_arg (stmt, i); | |
1902 | if (TREE_CODE (TREE_TYPE (arg)) != POINTER_TYPE) | |
1903 | continue; | |
1904 | /* If we have a nonnull-args, and either all pointers, or just | |
1905 | the specified pointers. */ | |
1906 | if (bitmap_empty_p (nonnull_args) | |
1907 | || bitmap_bit_p (nonnull_args, i)) | |
1908 | { | |
25ef215a DM |
1909 | state_t state = sm_ctxt->get_state (stmt, arg); |
1910 | /* Can't use a switch as the states are non-const. */ | |
1690a839 | 1911 | if (unchecked_p (state)) |
25ef215a | 1912 | { |
7d8f4240 | 1913 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a | 1914 | sm_ctxt->warn (node, stmt, arg, |
6341f14e DM |
1915 | make_unique<possible_null_arg> |
1916 | (*this, diag_arg, callee_fndecl, i)); | |
1690a839 DM |
1917 | const allocation_state *astate |
1918 | = as_a_allocation_state (state); | |
1919 | sm_ctxt->set_next_state (stmt, arg, | |
1920 | astate->get_nonnull ()); | |
25ef215a DM |
1921 | } |
1922 | else if (state == m_null) | |
1923 | { | |
7d8f4240 | 1924 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a | 1925 | sm_ctxt->warn (node, stmt, arg, |
6341f14e DM |
1926 | make_unique<null_arg> |
1927 | (*this, diag_arg, callee_fndecl, i)); | |
25ef215a DM |
1928 | sm_ctxt->set_next_state (stmt, arg, m_stop); |
1929 | } | |
5c6546ca DM |
1930 | else if (state == m_start) |
1931 | maybe_assume_non_null (sm_ctxt, arg, stmt); | |
757bf1df DM |
1932 | } |
1933 | } | |
1934 | BITMAP_FREE (nonnull_args); | |
1935 | } | |
1936 | } | |
c7e276b8 DM |
1937 | |
1938 | /* Check for this after nonnull, so that if we have both | |
1939 | then we transition to "freed", rather than "checked". */ | |
1940 | unsigned dealloc_argno = fndecl_dealloc_argno (callee_fndecl); | |
1941 | if (dealloc_argno != UINT_MAX) | |
1942 | { | |
1943 | const deallocator *d | |
1944 | = mutable_this->get_or_create_deallocator (callee_fndecl); | |
1945 | on_deallocator_call (sm_ctxt, node, call, d, dealloc_argno); | |
1946 | } | |
757bf1df DM |
1947 | } |
1948 | ||
5c6546ca DM |
1949 | /* Look for pointers explicitly being compared against zero |
1950 | that are in state assumed_non_null i.e. we already defererenced | |
1951 | them. | |
1952 | We have to do this check here, rather than in on_condition | |
1953 | because we add a constraint that the pointer is non-null when | |
1954 | dereferencing it, and this makes the apply_constraints_for_gcond | |
1955 | find known-true and known-false conditions; on_condition is only | |
1956 | called when adding new constraints. */ | |
1957 | if (const gcond *cond_stmt = dyn_cast <const gcond *> (stmt)) | |
1958 | { | |
1959 | enum tree_code op = gimple_cond_code (cond_stmt); | |
1960 | if (op == EQ_EXPR || op == NE_EXPR) | |
1961 | { | |
1962 | tree lhs = gimple_cond_lhs (cond_stmt); | |
1963 | tree rhs = gimple_cond_rhs (cond_stmt); | |
1964 | if (any_pointer_p (lhs) | |
1965 | && any_pointer_p (rhs) | |
1966 | && zerop (rhs)) | |
1967 | { | |
1968 | state_t state = sm_ctxt->get_state (stmt, lhs); | |
1969 | if (assumed_non_null_p (state)) | |
1970 | maybe_complain_about_deref_before_check | |
1971 | (sm_ctxt, node, | |
1972 | stmt, | |
1973 | (const assumed_non_null_state *)state, | |
1974 | lhs); | |
1975 | } | |
1976 | } | |
1977 | } | |
1978 | ||
808f4dfe | 1979 | if (tree lhs = sm_ctxt->is_zero_assignment (stmt)) |
8525d1f5 | 1980 | if (any_pointer_p (lhs)) |
1690a839 | 1981 | on_zero_assignment (sm_ctxt, stmt,lhs); |
757bf1df | 1982 | |
757bf1df DM |
1983 | /* Handle dereferences. */ |
1984 | for (unsigned i = 0; i < gimple_num_ops (stmt); i++) | |
1985 | { | |
1986 | tree op = gimple_op (stmt, i); | |
1987 | if (!op) | |
1988 | continue; | |
1989 | if (TREE_CODE (op) == COMPONENT_REF) | |
1990 | op = TREE_OPERAND (op, 0); | |
1991 | ||
1992 | if (TREE_CODE (op) == MEM_REF) | |
1993 | { | |
1994 | tree arg = TREE_OPERAND (op, 0); | |
757bf1df | 1995 | |
25ef215a | 1996 | state_t state = sm_ctxt->get_state (stmt, arg); |
5c6546ca DM |
1997 | if (state == m_start) |
1998 | maybe_assume_non_null (sm_ctxt, arg, stmt); | |
1999 | else if (unchecked_p (state)) | |
25ef215a | 2000 | { |
0f9aa35c | 2001 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a | 2002 | sm_ctxt->warn (node, stmt, arg, |
6341f14e DM |
2003 | make_unique<possible_null_deref> (*this, |
2004 | diag_arg)); | |
1690a839 DM |
2005 | const allocation_state *astate = as_a_allocation_state (state); |
2006 | sm_ctxt->set_next_state (stmt, arg, astate->get_nonnull ()); | |
25ef215a DM |
2007 | } |
2008 | else if (state == m_null) | |
2009 | { | |
0f9aa35c | 2010 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
25ef215a | 2011 | sm_ctxt->warn (node, stmt, arg, |
6341f14e | 2012 | make_unique<null_deref> (*this, diag_arg)); |
25ef215a DM |
2013 | sm_ctxt->set_next_state (stmt, arg, m_stop); |
2014 | } | |
1690a839 | 2015 | else if (freed_p (state)) |
25ef215a | 2016 | { |
0f9aa35c | 2017 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
1690a839 | 2018 | const allocation_state *astate = as_a_allocation_state (state); |
25ef215a | 2019 | sm_ctxt->warn (node, stmt, arg, |
6341f14e DM |
2020 | make_unique<use_after_free> |
2021 | (*this, diag_arg, astate->m_deallocator)); | |
25ef215a DM |
2022 | sm_ctxt->set_next_state (stmt, arg, m_stop); |
2023 | } | |
757bf1df DM |
2024 | } |
2025 | } | |
2026 | return false; | |
2027 | } | |
2028 | ||
5c6546ca DM |
2029 | /* Given a check against null of PTR in assumed-non-null state STATE, |
2030 | potentially add a deref_before_check warning to SM_CTXT. */ | |
2031 | ||
2032 | void | |
2033 | malloc_state_machine:: | |
2034 | maybe_complain_about_deref_before_check (sm_context *sm_ctxt, | |
2035 | const supernode *node, | |
2036 | const gimple *stmt, | |
2037 | const assumed_non_null_state *state, | |
2038 | tree ptr) const | |
2039 | { | |
2040 | const region_model *model = sm_ctxt->get_old_region_model (); | |
2041 | if (!model) | |
2042 | return; | |
2043 | ||
2044 | /* Don't complain if the current frame (where the check is occurring) is | |
2045 | deeper than the frame in which the "not null" assumption was made. | |
2046 | This suppress false positives for cases like: | |
2047 | ||
2048 | void foo (struct s *p) | |
2049 | { | |
2050 | int val = s->some_field; // deref here | |
2051 | shared_helper (p); | |
2052 | } | |
2053 | ||
2054 | where "shared_helper" has: | |
2055 | ||
2056 | void shared_helper (struct s *p) | |
2057 | { | |
2058 | if (!p) // check here | |
2059 | return; | |
2060 | // etc | |
2061 | } | |
2062 | ||
2063 | since the check in "shared_helper" is OK. */ | |
2064 | const frame_region *checked_in_frame = model->get_current_frame (); | |
2065 | const frame_region *assumed_nonnull_in_frame = state->m_frame; | |
2066 | if (checked_in_frame->get_index () > assumed_nonnull_in_frame->get_index ()) | |
2067 | return; | |
2068 | ||
2069 | tree diag_ptr = sm_ctxt->get_diagnostic_tree (ptr); | |
2070 | sm_ctxt->warn | |
2071 | (node, stmt, ptr, | |
2072 | make_unique<deref_before_check> (*this, diag_ptr)); | |
2073 | sm_ctxt->set_next_state (stmt, ptr, m_stop); | |
2074 | } | |
2075 | ||
c7e276b8 DM |
2076 | /* Handle a call to an allocator. |
2077 | RETURNS_NONNULL is true if CALL is to a fndecl known to have | |
2078 | __attribute__((returns_nonnull)). */ | |
1690a839 DM |
2079 | |
2080 | void | |
2081 | malloc_state_machine::on_allocator_call (sm_context *sm_ctxt, | |
2082 | const gcall *call, | |
c7e276b8 DM |
2083 | const deallocator_set *deallocators, |
2084 | bool returns_nonnull) const | |
1690a839 DM |
2085 | { |
2086 | tree lhs = gimple_call_lhs (call); | |
2087 | if (lhs) | |
2088 | { | |
2089 | if (sm_ctxt->get_state (call, lhs) == m_start) | |
c7e276b8 DM |
2090 | sm_ctxt->set_next_state (call, lhs, |
2091 | (returns_nonnull | |
2092 | ? deallocators->m_nonnull | |
2093 | : deallocators->m_unchecked)); | |
1690a839 DM |
2094 | } |
2095 | else | |
2096 | { | |
2097 | /* TODO: report leak. */ | |
2098 | } | |
2099 | } | |
2100 | ||
a61aaee6 DM |
2101 | /* Handle deallocations of non-heap pointers. |
2102 | non-heap -> stop, with warning. */ | |
2103 | ||
2104 | void | |
2105 | malloc_state_machine::handle_free_of_non_heap (sm_context *sm_ctxt, | |
2106 | const supernode *node, | |
2107 | const gcall *call, | |
2108 | tree arg, | |
2109 | const deallocator *d) const | |
2110 | { | |
2111 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); | |
2112 | const region *freed_reg = NULL; | |
2113 | if (const program_state *old_state = sm_ctxt->get_old_program_state ()) | |
2114 | { | |
2115 | const region_model *old_model = old_state->m_region_model; | |
2116 | const svalue *ptr_sval = old_model->get_rvalue (arg, NULL); | |
2117 | freed_reg = old_model->deref_rvalue (ptr_sval, arg, NULL); | |
2118 | } | |
2119 | sm_ctxt->warn (node, call, arg, | |
6341f14e DM |
2120 | make_unique<free_of_non_heap> |
2121 | (*this, diag_arg, freed_reg, d->m_name)); | |
a61aaee6 DM |
2122 | sm_ctxt->set_next_state (call, arg, m_stop); |
2123 | } | |
2124 | ||
1690a839 DM |
2125 | void |
2126 | malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt, | |
2127 | const supernode *node, | |
2128 | const gcall *call, | |
c7e276b8 DM |
2129 | const deallocator *d, |
2130 | unsigned argno) const | |
1690a839 | 2131 | { |
c7e276b8 DM |
2132 | if (argno >= gimple_call_num_args (call)) |
2133 | return; | |
2134 | tree arg = gimple_call_arg (call, argno); | |
1690a839 DM |
2135 | |
2136 | state_t state = sm_ctxt->get_state (call, arg); | |
2137 | ||
5c6546ca DM |
2138 | /* start/assumed_non_null/unchecked/nonnull -> freed. */ |
2139 | if (state == m_start || assumed_non_null_p (state)) | |
c7e276b8 | 2140 | sm_ctxt->set_next_state (call, arg, d->m_freed); |
1690a839 DM |
2141 | else if (unchecked_p (state) || nonnull_p (state)) |
2142 | { | |
2143 | const allocation_state *astate = as_a_allocation_state (state); | |
c7e276b8 DM |
2144 | gcc_assert (astate->m_deallocators); |
2145 | if (!astate->m_deallocators->contains_p (d)) | |
1690a839 DM |
2146 | { |
2147 | /* Wrong allocator. */ | |
0f9aa35c | 2148 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
6341f14e DM |
2149 | sm_ctxt->warn (node, call, arg, |
2150 | make_unique<mismatching_deallocation> | |
2151 | (*this, diag_arg, | |
2152 | astate->m_deallocators, | |
2153 | d)); | |
1690a839 | 2154 | } |
c7e276b8 | 2155 | sm_ctxt->set_next_state (call, arg, d->m_freed); |
1690a839 DM |
2156 | } |
2157 | ||
2158 | /* Keep state "null" as-is, rather than transitioning to "freed"; | |
2159 | we don't want to complain about double-free of NULL. */ | |
c7e276b8 | 2160 | else if (state == d->m_freed) |
1690a839 DM |
2161 | { |
2162 | /* freed -> stop, with warning. */ | |
0f9aa35c | 2163 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
1690a839 | 2164 | sm_ctxt->warn (node, call, arg, |
6341f14e | 2165 | make_unique<double_free> (*this, diag_arg, d->m_name)); |
1690a839 DM |
2166 | sm_ctxt->set_next_state (call, arg, m_stop); |
2167 | } | |
2168 | else if (state == m_non_heap) | |
2169 | { | |
2170 | /* non-heap -> stop, with warning. */ | |
a61aaee6 | 2171 | handle_free_of_non_heap (sm_ctxt, node, call, arg, d); |
1690a839 DM |
2172 | } |
2173 | } | |
2174 | ||
eafa9d96 DM |
2175 | /* Handle a call to "realloc". |
2176 | Check for free of non-heap or mismatching allocators, | |
2177 | transitioning to the "stop" state for such cases. | |
a6baafca | 2178 | |
6bd31b33 | 2179 | Otherwise, kf_realloc::impl_call_post will later |
eafa9d96 DM |
2180 | get called (which will handle other sm-state transitions |
2181 | when the state is bifurcated). */ | |
a6baafca DM |
2182 | |
2183 | void | |
2184 | malloc_state_machine::on_realloc_call (sm_context *sm_ctxt, | |
eafa9d96 | 2185 | const supernode *node, |
a6baafca DM |
2186 | const gcall *call) const |
2187 | { | |
eafa9d96 DM |
2188 | const unsigned argno = 0; |
2189 | const deallocator *d = &m_realloc; | |
2190 | ||
2191 | tree arg = gimple_call_arg (call, argno); | |
a6baafca | 2192 | |
eafa9d96 | 2193 | state_t state = sm_ctxt->get_state (call, arg); |
a6baafca | 2194 | |
a6baafca DM |
2195 | if (unchecked_p (state) || nonnull_p (state)) |
2196 | { | |
2197 | const allocation_state *astate = as_a_allocation_state (state); | |
2198 | gcc_assert (astate->m_deallocators); | |
eafa9d96 | 2199 | if (!astate->m_deallocators->contains_p (&m_free.m_deallocator)) |
a6baafca DM |
2200 | { |
2201 | /* Wrong allocator. */ | |
eafa9d96 | 2202 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); |
6341f14e DM |
2203 | sm_ctxt->warn (node, call, arg, |
2204 | make_unique<mismatching_deallocation> | |
2205 | (*this, diag_arg, | |
2206 | astate->m_deallocators, d)); | |
eafa9d96 DM |
2207 | sm_ctxt->set_next_state (call, arg, m_stop); |
2208 | if (path_context *path_ctxt = sm_ctxt->get_path_context ()) | |
2209 | path_ctxt->terminate_path (); | |
a6baafca DM |
2210 | } |
2211 | } | |
eafa9d96 DM |
2212 | else if (state == m_free.m_deallocator.m_freed) |
2213 | { | |
2214 | /* freed -> stop, with warning. */ | |
2215 | tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); | |
2216 | sm_ctxt->warn (node, call, arg, | |
6341f14e | 2217 | make_unique<double_free> (*this, diag_arg, "free")); |
eafa9d96 DM |
2218 | sm_ctxt->set_next_state (call, arg, m_stop); |
2219 | if (path_context *path_ctxt = sm_ctxt->get_path_context ()) | |
2220 | path_ctxt->terminate_path (); | |
2221 | } | |
2222 | else if (state == m_non_heap) | |
2223 | { | |
2224 | /* non-heap -> stop, with warning. */ | |
a61aaee6 | 2225 | handle_free_of_non_heap (sm_ctxt, node, call, arg, d); |
eafa9d96 DM |
2226 | if (path_context *path_ctxt = sm_ctxt->get_path_context ()) |
2227 | path_ctxt->terminate_path (); | |
2228 | } | |
a6baafca DM |
2229 | } |
2230 | ||
8525d1f5 DM |
2231 | /* Implementation of state_machine::on_phi vfunc for malloc_state_machine. */ |
2232 | ||
2233 | void | |
2234 | malloc_state_machine::on_phi (sm_context *sm_ctxt, | |
1690a839 | 2235 | const supernode *node ATTRIBUTE_UNUSED, |
8525d1f5 DM |
2236 | const gphi *phi, |
2237 | tree rhs) const | |
2238 | { | |
2239 | if (zerop (rhs)) | |
2240 | { | |
2241 | tree lhs = gimple_phi_result (phi); | |
1690a839 | 2242 | on_zero_assignment (sm_ctxt, phi, lhs); |
8525d1f5 DM |
2243 | } |
2244 | } | |
2245 | ||
757bf1df DM |
2246 | /* Implementation of state_machine::on_condition vfunc for malloc_state_machine. |
2247 | Potentially transition state 'unchecked' to 'nonnull' or to 'null'. */ | |
2248 | ||
2249 | void | |
2250 | malloc_state_machine::on_condition (sm_context *sm_ctxt, | |
1690a839 | 2251 | const supernode *node ATTRIBUTE_UNUSED, |
757bf1df | 2252 | const gimple *stmt, |
48e8a7a6 | 2253 | const svalue *lhs, |
757bf1df | 2254 | enum tree_code op, |
48e8a7a6 | 2255 | const svalue *rhs) const |
757bf1df | 2256 | { |
48e8a7a6 | 2257 | if (!rhs->all_zeroes_p ()) |
757bf1df DM |
2258 | return; |
2259 | ||
2260 | if (!any_pointer_p (lhs)) | |
2261 | return; | |
2262 | if (!any_pointer_p (rhs)) | |
2263 | return; | |
2264 | ||
2265 | if (op == NE_EXPR) | |
2266 | { | |
2267 | log ("got 'ARG != 0' match"); | |
1690a839 DM |
2268 | state_t s = sm_ctxt->get_state (stmt, lhs); |
2269 | if (unchecked_p (s)) | |
2270 | { | |
2271 | const allocation_state *astate = as_a_allocation_state (s); | |
2272 | sm_ctxt->set_next_state (stmt, lhs, astate->get_nonnull ()); | |
2273 | } | |
757bf1df DM |
2274 | } |
2275 | else if (op == EQ_EXPR) | |
2276 | { | |
2277 | log ("got 'ARG == 0' match"); | |
1690a839 DM |
2278 | state_t s = sm_ctxt->get_state (stmt, lhs); |
2279 | if (unchecked_p (s)) | |
2280 | sm_ctxt->set_next_state (stmt, lhs, m_null); | |
757bf1df DM |
2281 | } |
2282 | } | |
2283 | ||
5c6546ca DM |
2284 | /* Implementation of state_machine::on_pop_frame vfunc for malloc_state_machine. |
2285 | Clear any "assumed-non-null" state where the assumption happened in | |
2286 | FRAME_REG. */ | |
2287 | ||
2288 | void | |
2289 | malloc_state_machine::on_pop_frame (sm_state_map *smap, | |
2290 | const frame_region *frame_reg) const | |
2291 | { | |
2292 | hash_set<const svalue *> svals_to_clear; | |
2293 | for (auto kv : *smap) | |
2294 | { | |
2295 | const svalue *sval = kv.first; | |
2296 | state_t state = kv.second.m_state; | |
2297 | if (assumed_non_null_p (state)) | |
2298 | { | |
2299 | const assumed_non_null_state *assumed_state | |
2300 | = (const assumed_non_null_state *)state; | |
2301 | if (frame_reg == assumed_state->m_frame) | |
2302 | svals_to_clear.add (sval); | |
2303 | } | |
2304 | } | |
2305 | for (auto sval : svals_to_clear) | |
2306 | smap->clear_any_state (sval); | |
2307 | } | |
2308 | ||
757bf1df DM |
2309 | /* Implementation of state_machine::can_purge_p vfunc for malloc_state_machine. |
2310 | Don't allow purging of pointers in state 'unchecked' or 'nonnull' | |
2311 | (to avoid false leak reports). */ | |
2312 | ||
2313 | bool | |
2314 | malloc_state_machine::can_purge_p (state_t s) const | |
2315 | { | |
1690a839 DM |
2316 | enum resource_state rs = get_rs (s); |
2317 | return rs != RS_UNCHECKED && rs != RS_NONNULL; | |
757bf1df DM |
2318 | } |
2319 | ||
2320 | /* Implementation of state_machine::on_leak vfunc for malloc_state_machine | |
2321 | (for complaining about leaks of pointers in state 'unchecked' and | |
2322 | 'nonnull'). */ | |
2323 | ||
6341f14e | 2324 | std::unique_ptr<pending_diagnostic> |
757bf1df DM |
2325 | malloc_state_machine::on_leak (tree var) const |
2326 | { | |
6341f14e | 2327 | return make_unique<malloc_leak> (*this, var); |
757bf1df DM |
2328 | } |
2329 | ||
808f4dfe DM |
2330 | /* Implementation of state_machine::reset_when_passed_to_unknown_fn_p vfunc |
2331 | for malloc_state_machine. */ | |
2332 | ||
2333 | bool | |
2334 | malloc_state_machine::reset_when_passed_to_unknown_fn_p (state_t s, | |
2335 | bool is_mutable) const | |
2336 | { | |
2337 | /* An on-stack ptr doesn't stop being stack-allocated when passed to an | |
2338 | unknown fn. */ | |
2339 | if (s == m_non_heap) | |
2340 | return false; | |
2341 | ||
2342 | /* Otherwise, pointers passed as non-const can be freed. */ | |
2343 | return is_mutable; | |
2344 | } | |
2345 | ||
5c6546ca DM |
2346 | /* Implementation of state_machine::maybe_get_merged_states_nonequal vfunc |
2347 | for malloc_state_machine. | |
2348 | ||
2349 | Support discarding "assumed-non-null" states when merging with | |
2350 | start state. */ | |
2351 | ||
2352 | state_machine::state_t | |
2353 | malloc_state_machine::maybe_get_merged_states_nonequal (state_t state_a, | |
2354 | state_t state_b) const | |
2355 | { | |
2356 | if (assumed_non_null_p (state_a) && state_b == m_start) | |
2357 | return m_start; | |
2358 | if (state_a == m_start && assumed_non_null_p (state_b)) | |
2359 | return m_start; | |
2360 | return NULL; | |
2361 | } | |
2362 | ||
cd323d97 DM |
2363 | /* Return true if calls to FNDECL are known to not affect this sm-state. */ |
2364 | ||
2365 | bool | |
2366 | malloc_state_machine::unaffected_by_call_p (tree fndecl) | |
2367 | { | |
2368 | /* A set of functions that are known to not affect allocation | |
2369 | status, even if we haven't fully modelled the rest of their | |
2370 | behavior yet. */ | |
2371 | static const char * const funcnames[] = { | |
2372 | /* This array must be kept sorted. */ | |
2373 | "strsep", | |
2374 | }; | |
ca32b29e | 2375 | const size_t count = ARRAY_SIZE (funcnames); |
cd323d97 DM |
2376 | function_set fs (funcnames, count); |
2377 | ||
2378 | if (fs.contains_decl_p (fndecl)) | |
2379 | return true; | |
2380 | ||
2381 | return false; | |
2382 | } | |
2383 | ||
8525d1f5 DM |
2384 | /* Shared logic for handling GIMPLE_ASSIGNs and GIMPLE_PHIs that |
2385 | assign zero to LHS. */ | |
2386 | ||
2387 | void | |
2388 | malloc_state_machine::on_zero_assignment (sm_context *sm_ctxt, | |
8525d1f5 DM |
2389 | const gimple *stmt, |
2390 | tree lhs) const | |
2391 | { | |
1690a839 DM |
2392 | state_t s = sm_ctxt->get_state (stmt, lhs); |
2393 | enum resource_state rs = get_rs (s); | |
2394 | if (rs == RS_START | |
2395 | || rs == RS_UNCHECKED | |
2396 | || rs == RS_NONNULL | |
2397 | || rs == RS_FREED) | |
2398 | sm_ctxt->set_next_state (stmt, lhs, m_null); | |
8525d1f5 DM |
2399 | } |
2400 | ||
eafa9d96 DM |
2401 | /* Special-case hook for handling realloc, for the "success with move to |
2402 | a new buffer" case, marking OLD_PTR_SVAL as freed and NEW_PTR_SVAL as | |
2403 | non-null. | |
2404 | ||
2405 | This is similar to on_deallocator_call and on_allocator_call, | |
2406 | but the checks happen in on_realloc_call, and by splitting the states. */ | |
2407 | ||
2408 | void | |
2409 | malloc_state_machine:: | |
2410 | on_realloc_with_move (region_model *model, | |
2411 | sm_state_map *smap, | |
2412 | const svalue *old_ptr_sval, | |
2413 | const svalue *new_ptr_sval, | |
2414 | const extrinsic_state &ext_state) const | |
2415 | { | |
2416 | smap->set_state (model, old_ptr_sval, | |
2417 | m_free.m_deallocator.m_freed, | |
2418 | NULL, ext_state); | |
2419 | ||
2420 | smap->set_state (model, new_ptr_sval, | |
2421 | m_free.m_nonnull, | |
2422 | NULL, ext_state); | |
2423 | } | |
2424 | ||
757bf1df DM |
2425 | } // anonymous namespace |
2426 | ||
2427 | /* Internal interface to this file. */ | |
2428 | ||
2429 | state_machine * | |
2430 | make_malloc_state_machine (logger *logger) | |
2431 | { | |
2432 | return new malloc_state_machine (logger); | |
2433 | } | |
2434 | ||
eafa9d96 | 2435 | /* Specialcase hook for handling realloc, for use by |
6bd31b33 | 2436 | kf_realloc::impl_call_post::success_with_move::update_model. */ |
eafa9d96 DM |
2437 | |
2438 | void | |
2439 | region_model::on_realloc_with_move (const call_details &cd, | |
2440 | const svalue *old_ptr_sval, | |
2441 | const svalue *new_ptr_sval) | |
2442 | { | |
2443 | region_model_context *ctxt = cd.get_ctxt (); | |
2444 | if (!ctxt) | |
2445 | return; | |
2446 | const extrinsic_state *ext_state = ctxt->get_ext_state (); | |
2447 | if (!ext_state) | |
2448 | return; | |
2449 | ||
2450 | sm_state_map *smap; | |
2451 | const state_machine *sm; | |
2452 | unsigned sm_idx; | |
2453 | if (!ctxt->get_malloc_map (&smap, &sm, &sm_idx)) | |
2454 | return; | |
2455 | ||
2456 | gcc_assert (smap); | |
2457 | gcc_assert (sm); | |
2458 | ||
2459 | const malloc_state_machine &malloc_sm | |
2460 | = (const malloc_state_machine &)*sm; | |
2461 | ||
2462 | malloc_sm.on_realloc_with_move (this, | |
2463 | smap, | |
2464 | old_ptr_sval, | |
2465 | new_ptr_sval, | |
2466 | *ext_state); | |
2467 | } | |
2468 | ||
75038aa6 DM |
2469 | } // namespace ana |
2470 | ||
757bf1df | 2471 | #endif /* #if ENABLE_ANALYZER */ |