Line data Source code
1 : /* Classes for saving, deduplicating, and emitting analyzer diagnostics.
2 : Copyright (C) 2019-2026 Free Software Foundation, Inc.
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 "analyzer/common.h"
22 :
23 : #include "cfg.h"
24 : #include "gimple-pretty-print.h"
25 : #include "gimple-iterator.h"
26 : #include "inlining-iterator.h"
27 : #include "cgraph.h"
28 : #include "digraph.h"
29 : #include "gcc-rich-location.h"
30 : #include "diagnostics/sarif-sink.h"
31 :
32 : #include "analyzer/analyzer-logging.h"
33 : #include "analyzer/sm.h"
34 : #include "analyzer/pending-diagnostic.h"
35 : #include "analyzer/diagnostic-manager.h"
36 : #include "analyzer/call-string.h"
37 : #include "analyzer/program-point.h"
38 : #include "analyzer/store.h"
39 : #include "analyzer/region-model.h"
40 : #include "analyzer/constraint-manager.h"
41 : #include "analyzer/supergraph.h"
42 : #include "analyzer/program-state.h"
43 : #include "analyzer/exploded-graph.h"
44 : #include "analyzer/trimmed-graph.h"
45 : #include "analyzer/feasible-graph.h"
46 : #include "analyzer/checker-path.h"
47 : #include "analyzer/reachability.h"
48 :
49 : #if ENABLE_ANALYZER
50 :
51 : namespace ana {
52 :
53 : class feasible_worklist;
54 :
55 : // struct pending_location
56 :
57 921 : pending_location::pending_location ()
58 921 : : m_enode (nullptr),
59 921 : m_event_loc_info (UNKNOWN_LOCATION, NULL_TREE, 0)
60 : {
61 921 : }
62 :
63 7043 : pending_location::pending_location (exploded_node *enode)
64 7043 : : m_enode (enode),
65 7043 : m_event_loc_info (enode)
66 : {
67 7043 : }
68 :
69 3582 : pending_location::pending_location (exploded_node *enode,
70 3582 : location_t loc)
71 3582 : : m_enode (enode),
72 3582 : m_event_loc_info (enode)
73 : {
74 3582 : m_event_loc_info.m_loc = loc;
75 3582 : }
76 :
77 : std::unique_ptr<json::object>
78 36 : pending_location::to_json () const
79 : {
80 36 : auto ploc_obj = std::make_unique<json::object> ();
81 :
82 36 : if (m_enode)
83 36 : ploc_obj->set_integer ("enode", m_enode->m_index);
84 : // TODO: also store m_event_loc_info
85 36 : return ploc_obj;
86 : }
87 :
88 : /* State for finding the shortest feasible exploded_path for a
89 : saved_diagnostic.
90 : This is shared between all diagnostics, so that we avoid repeating work. */
91 :
92 : class epath_finder
93 : {
94 : public:
95 1556 : epath_finder (const exploded_graph &eg)
96 1556 : : m_eg (eg),
97 1556 : m_sep (nullptr)
98 : {
99 : /* This is shared by all diagnostics, but only needed if
100 : !flag_analyzer_feasibility. */
101 1556 : if (!flag_analyzer_feasibility)
102 4 : m_sep = new shortest_exploded_paths (eg, eg.get_origin (),
103 4 : SPS_FROM_GIVEN_ORIGIN);
104 1556 : }
105 :
106 1560 : ~epath_finder () { delete m_sep; }
107 :
108 153340 : logger *get_logger () const { return m_eg.get_logger (); }
109 :
110 : std::unique_ptr<exploded_path>
111 : get_best_epath (const exploded_node *target_enode,
112 : const pending_diagnostic &pd,
113 : const char *desc, unsigned diag_idx,
114 : std::unique_ptr<feasibility_problem> *out_problem);
115 :
116 : private:
117 : DISABLE_COPY_AND_ASSIGN(epath_finder);
118 :
119 : std::unique_ptr<exploded_path>
120 : explore_feasible_paths (const exploded_node *target_enode,
121 : const pending_diagnostic &pd,
122 : const char *desc, unsigned diag_idx);
123 : bool
124 : process_worklist_item (feasible_worklist *worklist,
125 : const trimmed_graph &tg,
126 : feasible_graph *fg,
127 : const exploded_node *target_enode,
128 : const pending_diagnostic &pd,
129 : unsigned diag_idx,
130 : std::unique_ptr<exploded_path> *out_best_path) const;
131 : void dump_trimmed_graph (const exploded_node *target_enode,
132 : const char *desc, unsigned diag_idx,
133 : const trimmed_graph &tg,
134 : const shortest_paths<eg_traits, exploded_path> &sep);
135 : void dump_feasible_graph (const exploded_node *target_enode,
136 : const char *desc, unsigned diag_idx,
137 : const feasible_graph &fg);
138 : void dump_feasible_path (const exploded_node *target_enode,
139 : unsigned diag_idx,
140 : const feasible_graph &fg,
141 : const feasible_node &fnode) const;
142 :
143 : const exploded_graph &m_eg;
144 : shortest_exploded_paths *m_sep;
145 : };
146 :
147 : /* class epath_finder. */
148 :
149 : /* Get the "best" exploded_path for reaching TARGET_ENODE from the origin,
150 : returning ownership of it to the caller.
151 :
152 : Ideally we want to report the shortest feasible path.
153 : Return nullptr if we could not find a feasible path
154 : (when flag_analyzer_feasibility is true).
155 :
156 : If flag_analyzer_feasibility is false, then simply return the
157 : shortest path.
158 :
159 : Use DESC and DIAG_IDX when logging.
160 :
161 : Write any feasibility_problem to *OUT_PROBLEM. */
162 :
163 : std::unique_ptr<exploded_path>
164 6375 : epath_finder::get_best_epath (const exploded_node *target_enode,
165 : const pending_diagnostic &pd,
166 : const char *desc, unsigned diag_idx,
167 : std::unique_ptr<feasibility_problem> *out_problem)
168 : {
169 6375 : logger *logger = get_logger ();
170 6375 : LOG_SCOPE (logger);
171 :
172 6375 : unsigned snode_id = target_enode->get_supernode ()->m_id;
173 6375 : if (logger)
174 2 : logger->log ("considering %qs at EN: %i, SN: %i (sd: %i)",
175 2 : desc, target_enode->m_index, snode_id, diag_idx);
176 :
177 : /* State-merging means that not every path in the egraph corresponds
178 : to a feasible one w.r.t. states.
179 :
180 : We want to find the shortest feasible path from the origin to ENODE
181 : in the egraph. */
182 :
183 6375 : if (flag_analyzer_feasibility)
184 : {
185 : /* Attempt to find the shortest feasible path using feasible_graph. */
186 6371 : if (logger)
187 2 : logger->log ("trying to find shortest feasible path");
188 6371 : if (std::unique_ptr<exploded_path> epath
189 6371 : = explore_feasible_paths (target_enode, pd, desc, diag_idx))
190 : {
191 6089 : if (logger)
192 2 : logger->log ("accepting %qs at EN: %i, SN: %i (sd: %i)"
193 : " with feasible path (length: %i)",
194 2 : desc, target_enode->m_index, snode_id, diag_idx,
195 : epath->length ());
196 6089 : return epath;
197 : }
198 : else
199 : {
200 282 : if (logger)
201 0 : logger->log ("rejecting %qs at EN: %i, SN: %i (sd: %i)"
202 : " due to not finding feasible path",
203 0 : desc, target_enode->m_index, snode_id, diag_idx);
204 282 : return nullptr;
205 6371 : }
206 : }
207 : else
208 : {
209 : /* As a crude approximation to shortest feasible path, simply find
210 : the shortest path, and note whether it is feasible.
211 : There could be longer feasible paths within the egraph, so this
212 : approach would lead to diagnostics being falsely rejected
213 : (PR analyzer/96374). */
214 4 : if (logger)
215 0 : logger->log ("trying to find shortest path ignoring feasibility");
216 4 : gcc_assert (m_sep);
217 4 : auto epath
218 : = std::make_unique<exploded_path>
219 4 : (m_sep->get_shortest_path (target_enode));
220 4 : if (epath->feasible_p (logger, out_problem, m_eg.get_engine (), &m_eg))
221 : {
222 0 : if (logger)
223 0 : logger->log ("accepting %qs at EN: %i, SN: %i (sn: %i)"
224 : " with feasible path (length: %i)",
225 0 : desc, target_enode->m_index, snode_id, diag_idx,
226 : epath->length ());
227 : }
228 : else
229 : {
230 4 : if (logger)
231 0 : logger->log ("accepting %qs at EN: %i, SN: %i (sn: %i) (length: %i)"
232 : " despite infeasible path (due to %qs)",
233 0 : desc, target_enode->m_index, snode_id, diag_idx,
234 : epath->length (),
235 : "-fno-analyzer-feasibility");
236 : }
237 4 : return epath;
238 4 : }
239 6375 : }
240 :
241 : /* A class for managing the worklist of feasible_nodes in
242 : epath_finder::explore_feasible_paths, prioritizing them
243 : so that shorter paths appear earlier in the queue. */
244 :
245 12742 : class feasible_worklist
246 : {
247 : public:
248 6371 : feasible_worklist (const shortest_paths<eg_traits, exploded_path> &sep)
249 12742 : : m_queue (key_t (*this, nullptr)),
250 6371 : m_sep (sep)
251 : {
252 6371 : }
253 :
254 134219 : feasible_node *take_next () { return m_queue.extract_min (); }
255 :
256 137488 : void add_node (feasible_node *fnode)
257 : {
258 274976 : m_queue.insert (key_t (*this, fnode), fnode);
259 131117 : }
260 :
261 : private:
262 : struct key_t
263 : {
264 143859 : key_t (const feasible_worklist &w, feasible_node *fnode)
265 6371 : : m_worklist (w), m_fnode (fnode)
266 : {}
267 :
268 147191 : bool operator< (const key_t &other) const
269 : {
270 147191 : return cmp (*this, other) < 0;
271 : }
272 :
273 45761 : bool operator== (const key_t &other) const
274 : {
275 45761 : return cmp (*this, other) == 0;
276 : }
277 :
278 45761 : bool operator> (const key_t &other) const
279 : {
280 45761 : return !(*this == other || *this < other);
281 : }
282 :
283 : private:
284 192952 : static int cmp (const key_t &ka, const key_t &kb)
285 : {
286 : /* Choose the node for which if the remaining path were feasible,
287 : it would be the shortest path (summing the length of the
288 : known-feasible path so far with that of the remaining
289 : possibly-feasible path). */
290 192952 : int ca = ka.m_worklist.get_estimated_cost (ka.m_fnode);
291 192952 : int cb = kb.m_worklist.get_estimated_cost (kb.m_fnode);
292 192952 : return ca - cb;
293 : }
294 :
295 : const feasible_worklist &m_worklist;
296 : feasible_node *m_fnode;
297 : };
298 :
299 : /* Get the estimated length of a path involving FNODE from
300 : the origin to the target enode.
301 : Sum the length of the known-feasible path so far with
302 : that of the remaining possibly-feasible path. */
303 :
304 385904 : int get_estimated_cost (const feasible_node *fnode) const
305 : {
306 385904 : unsigned length_so_far = fnode->get_path_length ();
307 385904 : int shortest_remaining_path
308 385904 : = m_sep.get_shortest_distance (fnode->get_inner_node ());
309 :
310 385904 : gcc_assert (shortest_remaining_path >= 0);
311 : /* This should be true since we're only exploring nodes within
312 : the trimmed graph (and we anticipate it being much smaller
313 : than this, and thus not overflowing the sum). */
314 385904 : gcc_assert (shortest_remaining_path < INT_MAX);
315 :
316 385904 : return length_so_far + shortest_remaining_path;
317 : }
318 :
319 : /* Priority queue, backed by a fibonacci_heap. */
320 : typedef fibonacci_heap<key_t, feasible_node> queue_t;
321 : queue_t m_queue;
322 : const shortest_paths<eg_traits, exploded_path> &m_sep;
323 : };
324 :
325 : /* When we're building the exploded graph we want to simplify
326 : overly-complicated symbolic values down to "UNKNOWN" to try to avoid
327 : state explosions and unbounded chains of exploration.
328 :
329 : However, when we're building the feasibility graph for a diagnostic
330 : (actually a tree), we don't want UNKNOWN values, as conditions on them
331 : are also unknown: we don't want to have a contradiction such as a path
332 : where (VAL != 0) and then (VAL == 0) along the same path.
333 :
334 : Hence this is an RAII class for temporarily disabling complexity-checking
335 : in the region_model_manager, for use within
336 : epath_finder::explore_feasible_paths.
337 :
338 : We also disable the creation of unknown_svalue instances during feasibility
339 : checking, instead creating unique svalues, to avoid paradoxes in paths. */
340 :
341 : class auto_checking_feasibility
342 : {
343 : public:
344 6371 : auto_checking_feasibility (region_model_manager *mgr) : m_mgr (mgr)
345 : {
346 6371 : m_mgr->begin_checking_feasibility ();
347 6371 : }
348 6371 : ~auto_checking_feasibility ()
349 : {
350 6371 : m_mgr->end_checking_feasibility ();
351 : }
352 : private:
353 : region_model_manager *m_mgr;
354 : };
355 :
356 : /* Attempt to find the shortest feasible path from the origin to
357 : TARGET_ENODE by iteratively building a feasible_graph, in which
358 : every path to a feasible_node is feasible by construction.
359 :
360 : We effectively explore the tree of feasible paths in order of shortest
361 : path until we either find a feasible path to TARGET_ENODE, or hit
362 : a limit and give up.
363 :
364 : Preliminaries:
365 : - Find the shortest path from each node to the TARGET_ENODE (without
366 : checking feasibility), so that we can prioritize our worklist.
367 : - Construct a trimmed_graph: the subset of nodes/edges that
368 : are on a path that eventually reaches TARGET_ENODE. We will only need
369 : to consider these when considering the shortest feasible path.
370 :
371 : Build a feasible_graph, in which every path to a feasible_node
372 : is feasible by construction.
373 : We use a worklist to flatten the exploration into an iteration.
374 : Starting at the origin, find feasible out-edges within the trimmed graph.
375 : At each stage, choose the node for which if the remaining path were feasible,
376 : it would be the shortest path (summing the length of the known-feasible path
377 : so far with that of the remaining possibly-feasible path).
378 : This way, the first feasible path we find to TARGET_ENODE is the shortest.
379 : We start by trying the shortest possible path, but if that fails,
380 : we explore progressively longer paths, eventually trying iterations through
381 : loops. The exploration is captured in the feasible_graph, which can be
382 : dumped as a .dot file to visualize the exploration. The indices of the
383 : feasible_nodes show the order in which they were created.
384 :
385 : This is something of a brute-force approach, but the trimmed_graph
386 : hopefully keeps the complexity manageable.
387 :
388 : Terminate with failure when the number of infeasible edges exceeds
389 : a threshold (--param=analyzer-max-infeasible-edges=).
390 : This is guaranteed to eventually lead to terminatation, as
391 : we can't keep creating feasible nodes without eventually
392 : either reaching an infeasible edge, or reaching the
393 : TARGET_ENODE. Specifically, there can't be a cycle of
394 : feasible edges that doesn't reach the target_enode without
395 : an out-edge that either fails feasibility or gets closer
396 : to the TARGET_ENODE: on each iteration we are either:
397 : - effectively getting closer to the TARGET_ENODE (which can't
398 : continue forever without reaching the target), or
399 : - getting monotonically closer to the termination threshold. */
400 :
401 : std::unique_ptr<exploded_path>
402 6371 : epath_finder::explore_feasible_paths (const exploded_node *target_enode,
403 : const pending_diagnostic &pd,
404 : const char *desc, unsigned diag_idx)
405 : {
406 6371 : logger *logger = get_logger ();
407 6371 : LOG_SCOPE (logger);
408 :
409 6371 : region_model_manager *mgr = m_eg.get_engine ()->get_model_manager ();
410 :
411 : /* Determine the shortest path to TARGET_ENODE from each node in
412 : the exploded graph. */
413 6371 : shortest_paths<eg_traits, exploded_path> sep
414 6371 : (m_eg, target_enode, SPS_TO_GIVEN_TARGET);
415 :
416 : /* Construct a trimmed_graph: the subset of nodes/edges that
417 : are on a path that eventually reaches TARGET_ENODE.
418 : We only need to consider these when considering the shortest
419 : feasible path. */
420 6371 : trimmed_graph tg (m_eg, target_enode);
421 :
422 6371 : if (flag_dump_analyzer_feasibility)
423 4 : dump_trimmed_graph (target_enode, desc, diag_idx, tg, sep);
424 :
425 6371 : feasible_graph fg;
426 6371 : feasible_worklist worklist (sep);
427 :
428 : /* Populate the worklist with the origin node. */
429 6371 : {
430 6371 : feasibility_state init_state (mgr, m_eg.get_supergraph ());
431 6371 : feasible_node *origin = fg.add_node (m_eg.get_origin (), init_state, 0);
432 6371 : worklist.add_node (origin);
433 6371 : }
434 :
435 : /* Iteratively explore the tree of feasible paths in order of shortest
436 : path until we either find a feasible path to TARGET_ENODE, or hit
437 : a limit. */
438 :
439 : /* Set this if we find a feasible path to TARGET_ENODE. */
440 6371 : std::unique_ptr<exploded_path> best_path = nullptr;
441 :
442 6371 : {
443 6371 : auto_checking_feasibility sentinel (mgr);
444 :
445 134219 : while (process_worklist_item (&worklist, tg, &fg, target_enode,
446 : pd, diag_idx, &best_path))
447 : {
448 : /* Empty; the work is done within process_worklist_item. */
449 : }
450 6371 : }
451 :
452 6371 : if (logger)
453 : {
454 2 : logger->log ("tg for sd: %i:", diag_idx);
455 2 : logger->inc_indent ();
456 2 : tg.log_stats (logger);
457 2 : logger->dec_indent ();
458 :
459 2 : logger->log ("fg for sd: %i:", diag_idx);
460 2 : logger->inc_indent ();
461 2 : fg.log_stats (logger);
462 2 : logger->dec_indent ();
463 : }
464 :
465 : /* Dump the feasible_graph. */
466 6371 : if (flag_dump_analyzer_feasibility)
467 4 : dump_feasible_graph (target_enode, desc, diag_idx, fg);
468 :
469 6371 : return best_path;
470 12742 : }
471 :
472 : /* Process the next item in WORKLIST, potentially adding new items
473 : based on feasible out-edges, and extending FG accordingly.
474 : Use TG to ignore out-edges that don't lead to TARGET_ENODE.
475 : Return true if the worklist processing should continue.
476 : Return false if the processing of the worklist should stop
477 : (either due to reaching TARGET_ENODE, or hitting a limit).
478 : Write to *OUT_BEST_PATH if stopping due to finding a feasible path
479 : to TARGET_ENODE.
480 : Use PD to provide additional restrictions on feasibility of
481 : the final path in the feasible_graph before converting to
482 : an exploded_path. */
483 :
484 : bool
485 134219 : epath_finder::
486 : process_worklist_item (feasible_worklist *worklist,
487 : const trimmed_graph &tg,
488 : feasible_graph *fg,
489 : const exploded_node *target_enode,
490 : const pending_diagnostic &pd,
491 : unsigned diag_idx,
492 : std::unique_ptr<exploded_path> *out_best_path) const
493 : {
494 134219 : logger *logger = get_logger ();
495 :
496 134219 : feasible_node *fnode = worklist->take_next ();
497 134219 : if (!fnode)
498 : {
499 63 : if (logger)
500 0 : logger->log ("drained worklist for sd: %i"
501 : " without finding feasible path",
502 : diag_idx);
503 63 : return false;
504 : }
505 :
506 134156 : log_scope s (logger, "fg worklist item",
507 : "considering FN: %i (EN: %i) for sd: %i",
508 134156 : fnode->get_index (), fnode->get_inner_node ()->m_index,
509 134156 : diag_idx);
510 :
511 : /* Iterate through all out-edges from this item. */
512 134156 : unsigned i;
513 134156 : exploded_edge *succ_eedge;
514 320710 : FOR_EACH_VEC_ELT (fnode->get_inner_node ()->m_succs, i, succ_eedge)
515 : {
516 192862 : log_scope s (logger, "edge", "considering edge: EN:%i -> EN:%i",
517 192862 : succ_eedge->m_src->m_index,
518 192862 : succ_eedge->m_dest->m_index);
519 : /* Reject edges that aren't in the trimmed graph. */
520 192862 : if (!tg.contains_p (succ_eedge))
521 : {
522 53337 : if (logger)
523 1 : logger->log ("rejecting: not in trimmed graph");
524 53337 : continue;
525 : }
526 :
527 139525 : feasibility_state succ_state (fnode->get_state ());
528 139525 : std::unique_ptr<rejected_constraint> rc;
529 139525 : if (succ_state.maybe_update_for_edge (logger, succ_eedge, nullptr, &rc))
530 : {
531 137268 : gcc_assert (rc == nullptr);
532 137268 : feasible_node *succ_fnode
533 137268 : = fg->add_node (succ_eedge->m_dest,
534 : succ_state,
535 137268 : fnode->get_path_length () + 1);
536 137268 : if (logger)
537 14 : logger->log ("accepting as FN: %i", succ_fnode->get_index ());
538 137268 : fg->add_edge (new feasible_edge (fnode, succ_fnode, succ_eedge));
539 :
540 : /* Have we reached TARGET_ENODE? */
541 137268 : if (succ_fnode->get_inner_node () == target_enode)
542 : {
543 6151 : if (logger)
544 2 : logger->log ("success: got feasible path to EN: %i (sd: %i)"
545 : " (length: %i)",
546 2 : target_enode->m_index, diag_idx,
547 : succ_fnode->get_path_length ());
548 6151 : if (!pd.check_valid_fpath_p (*succ_fnode))
549 : {
550 62 : if (logger)
551 0 : logger->log ("rejecting feasible path due to"
552 : " pending_diagnostic");
553 62 : return false;
554 : }
555 6089 : *out_best_path = fg->make_epath (succ_fnode);
556 6089 : if (flag_dump_analyzer_feasibility)
557 4 : dump_feasible_path (target_enode, diag_idx, *fg, *succ_fnode);
558 :
559 : /* Success: stop the worklist iteration. */
560 6089 : return false;
561 : }
562 : else
563 131117 : worklist->add_node (succ_fnode);
564 : }
565 : else
566 : {
567 2257 : if (logger)
568 0 : logger->log ("infeasible");
569 2257 : gcc_assert (rc);
570 2257 : fg->add_feasibility_problem (fnode,
571 : succ_eedge,
572 : std::move (rc));
573 :
574 : /* Give up if there have been too many infeasible edges. */
575 2257 : if (fg->get_num_infeasible ()
576 2257 : > (unsigned)param_analyzer_max_infeasible_edges)
577 : {
578 157 : if (logger)
579 0 : logger->log ("too many infeasible edges (%i); giving up",
580 : fg->get_num_infeasible ());
581 157 : return false;
582 : }
583 : }
584 192862 : }
585 :
586 : /* Continue the worklist iteration. */
587 : return true;
588 134156 : }
589 :
590 : /* Helper class for epath_finder::dump_trimmed_graph
591 : to dump extra per-node information.
592 : Use SEP to add the length of the shortest path from each
593 : node to the target node to each node's dump. */
594 :
595 : class dump_eg_with_shortest_path : public eg_traits::dump_args_t
596 : {
597 : public:
598 4 : dump_eg_with_shortest_path
599 : (const exploded_graph &eg,
600 : const shortest_paths<eg_traits, exploded_path> &sep)
601 4 : : dump_args_t (eg),
602 4 : m_sep (sep)
603 : {
604 : }
605 :
606 74 : void dump_extra_info (const exploded_node *enode,
607 : pretty_printer *pp) const final override
608 : {
609 144 : pp_printf (pp, "sp: %i", m_sep.get_shortest_path (enode).length ());
610 74 : pp_newline (pp);
611 74 : }
612 :
613 : private:
614 : const shortest_paths<eg_traits, exploded_path> &m_sep;
615 : };
616 :
617 : /* Dump TG to "BASE_NAME.DESC.DIAG_IDX.to-enN.tg.dot",
618 : annotating each node with the length of the shortest path
619 : from that node to TARGET_ENODE (using SEP). */
620 :
621 : void
622 4 : epath_finder::
623 : dump_trimmed_graph (const exploded_node *target_enode,
624 : const char *desc, unsigned diag_idx,
625 : const trimmed_graph &tg,
626 : const shortest_paths<eg_traits, exploded_path> &sep)
627 : {
628 4 : auto_timevar tv (TV_ANALYZER_DUMP);
629 4 : dump_eg_with_shortest_path inner_args (m_eg, sep);
630 4 : trimmed_graph::dump_args_t args (inner_args);
631 4 : pretty_printer pp;
632 4 : pp_printf (&pp, "%s.%s.%i.to-en%i.tg.dot",
633 4 : dump_base_name, desc, diag_idx, target_enode->m_index);
634 4 : char *filename = xstrdup (pp_formatted_text (&pp));
635 4 : tg.dump_dot (filename, nullptr, args);
636 4 : free (filename);
637 4 : }
638 :
639 : /* Dump FG to "BASE_NAME.DESC.DIAG_IDX.to-enN.fg.dot". */
640 :
641 : void
642 4 : epath_finder::dump_feasible_graph (const exploded_node *target_enode,
643 : const char *desc, unsigned diag_idx,
644 : const feasible_graph &fg)
645 : {
646 4 : auto_timevar tv (TV_ANALYZER_DUMP);
647 4 : exploded_graph::dump_args_t inner_args (m_eg);
648 4 : feasible_graph::dump_args_t args (inner_args);
649 4 : pretty_printer pp;
650 4 : pp_printf (&pp, "%s.%s.%i.to-en%i.fg.dot",
651 4 : dump_base_name, desc, diag_idx, target_enode->m_index);
652 4 : char *filename = xstrdup (pp_formatted_text (&pp));
653 4 : fg.dump_dot (filename, nullptr, args);
654 4 : free (filename);
655 4 : }
656 :
657 : /* Dump the path to FNODE to "BASE_NAME.DIAG_IDX.to-enN.fpath.txt". */
658 :
659 : void
660 4 : epath_finder::dump_feasible_path (const exploded_node *target_enode,
661 : unsigned diag_idx,
662 : const feasible_graph &fg,
663 : const feasible_node &fnode) const
664 : {
665 4 : auto_timevar tv (TV_ANALYZER_DUMP);
666 4 : pretty_printer pp;
667 4 : pp_printf (&pp, "%s.%i.to-en%i.fpath.txt",
668 4 : dump_base_name, diag_idx, target_enode->m_index);
669 4 : char *filename = xstrdup (pp_formatted_text (&pp));
670 4 : fg.dump_feasible_path (fnode, filename);
671 4 : free (filename);
672 4 : }
673 :
674 : /* class saved_diagnostic. */
675 :
676 : /* saved_diagnostic's ctor. */
677 :
678 6375 : saved_diagnostic::saved_diagnostic (const state_machine *sm,
679 : pending_location &&ploc,
680 : tree var,
681 : const svalue *sval,
682 : state_machine::state_t state,
683 : std::unique_ptr<pending_diagnostic> d,
684 6375 : unsigned idx)
685 6375 : : m_sm (sm),
686 6375 : m_ploc (std::move (ploc)),
687 6375 : m_var (var), m_sval (sval), m_state (state),
688 6375 : m_d (std::move (d)), m_trailing_eedge (nullptr),
689 6375 : m_idx (idx),
690 6375 : m_best_epath (nullptr), m_problem (nullptr),
691 6375 : m_notes ()
692 : {
693 : /* We must have an enode in order to be able to look for paths
694 : through the exploded_graph to this diagnostic. */
695 6375 : gcc_assert (m_ploc.m_enode);
696 6375 : }
697 :
698 : const supernode *
699 131526 : saved_diagnostic::get_supernode () const
700 : {
701 131526 : return m_ploc.m_enode->get_supernode ();
702 : }
703 :
704 : bool
705 44107 : saved_diagnostic::operator== (const saved_diagnostic &other) const
706 : {
707 46253 : if (m_notes.length () != other.m_notes.length ())
708 : return false;
709 43655 : for (unsigned i = 0; i < m_notes.length (); i++)
710 734 : if (!m_notes[i]->equal_p (*other.m_notes[i]))
711 : return false;
712 :
713 : // Don't deduplicate dump_path_diagnostic instances
714 42921 : if (!strcmp (m_d->get_kind (), "dump_path_diagnostic"))
715 1980 : return this == &other;
716 :
717 40941 : return (m_sm == other.m_sm
718 : /* We don't compare m_enode. */
719 35812 : && get_supernode () == other.get_supernode ()
720 6770 : && (m_ploc.m_event_loc_info.m_loc
721 6770 : == other.m_ploc.m_event_loc_info.m_loc)
722 6506 : && pending_diagnostic::same_tree_p (m_var, other.m_var)
723 6052 : && m_state == other.m_state
724 5990 : && m_d->equal_p (*other.m_d)
725 46765 : && m_trailing_eedge == other.m_trailing_eedge);
726 : }
727 :
728 : /* Add PN to this diagnostic, taking ownership of it. */
729 :
730 : void
731 194 : saved_diagnostic::add_note (std::unique_ptr<pending_note> pn)
732 : {
733 194 : gcc_assert (pn);
734 194 : m_notes.safe_push (pn.release ());
735 194 : }
736 :
737 : /* Add EVENT to this diagnostic. */
738 :
739 : void
740 159 : saved_diagnostic::add_event (std::unique_ptr<checker_event> event)
741 : {
742 159 : gcc_assert (event);
743 159 : m_saved_events.safe_push (event.release ());
744 159 : }
745 :
746 : /* Return a new json::object of the form
747 : {"sm": optional str,
748 : "ploc": {},
749 : "sval": optional str,
750 : "state": optional str,
751 : "path_length": optional int,
752 : "pending_diagnostic": str,
753 : "idx": int}. */
754 :
755 : std::unique_ptr<json::object>
756 0 : saved_diagnostic::to_json () const
757 : {
758 0 : auto sd_obj = std::make_unique<json::object> ();
759 :
760 0 : if (m_sm)
761 0 : sd_obj->set_string ("sm", m_sm->get_name ());
762 0 : sd_obj->set ("ploc", m_ploc.to_json ());
763 0 : if (m_sval)
764 0 : sd_obj->set ("sval", m_sval->to_json ());
765 0 : if (m_state)
766 0 : sd_obj->set ("state", m_state->to_json ());
767 0 : if (m_best_epath)
768 0 : sd_obj->set_integer ("path_length", get_epath_length ());
769 0 : sd_obj->set_string ("pending_diagnostic", m_d->get_kind ());
770 0 : sd_obj->set_integer ("idx", m_idx);
771 :
772 0 : return sd_obj;
773 : }
774 :
775 : /* Dump this to PP in a form suitable for use as an id in .dot output. */
776 :
777 : void
778 16 : saved_diagnostic::dump_dot_id (pretty_printer *pp) const
779 : {
780 16 : pp_printf (pp, "sd_%i", m_idx);
781 16 : }
782 :
783 : /* Dump this to PP in a form suitable for use as a node in .dot output. */
784 :
785 : void
786 8 : saved_diagnostic::dump_as_dot_node (pretty_printer *pp) const
787 : {
788 8 : dump_dot_id (pp);
789 8 : pp_printf (pp,
790 : " [shape=none,margin=0,style=filled,fillcolor=\"red\",label=\"");
791 8 : pp_write_text_to_stream (pp);
792 :
793 : /* Node label. */
794 8 : pp_printf (pp, "DIAGNOSTIC: %s (sd: %i)\n",
795 8 : m_d->get_kind (), m_idx);
796 8 : if (m_sm)
797 : {
798 8 : pp_printf (pp, "sm: %s", m_sm->get_name ());
799 8 : if (m_state)
800 : {
801 8 : pp_printf (pp, "; state: ");
802 8 : m_state->dump_to_pp (pp);
803 : }
804 8 : pp_newline (pp);
805 : }
806 8 : if (m_var)
807 8 : pp_printf (pp, "var: %qE\n", m_var);
808 8 : if (m_sval)
809 : {
810 8 : pp_string (pp, "sval: ");
811 8 : m_sval->dump_to_pp (pp, true);
812 8 : pp_newline (pp);
813 : }
814 8 : if (m_best_epath)
815 0 : pp_printf (pp, "path length: %i\n", get_epath_length ());
816 :
817 8 : pp_write_text_as_dot_label_to_stream (pp, /*for_record=*/true);
818 8 : pp_string (pp, "\"];\n\n");
819 :
820 : /* Show links to duplicates. */
821 8 : for (auto iter : m_duplicates)
822 : {
823 0 : dump_dot_id (pp);
824 0 : pp_string (pp, " -> ");
825 0 : iter->dump_dot_id (pp);
826 0 : pp_string (pp, " [style=\"dotted\" arrowhead=\"none\"];");
827 0 : pp_newline (pp);
828 : }
829 8 : }
830 :
831 : /* Use PF to find the best exploded_path for this saved_diagnostic, if any,
832 : and store it in m_best_epath.
833 : Return true if a best path was found. */
834 :
835 : bool
836 6375 : saved_diagnostic::calc_best_epath (epath_finder *pf)
837 : {
838 6375 : logger *logger = pf->get_logger ();
839 6375 : LOG_SCOPE (logger);
840 6375 : m_problem = nullptr;
841 :
842 6375 : m_best_epath = pf->get_best_epath (m_ploc.m_enode,
843 6375 : *m_d, m_d->get_kind (), m_idx,
844 6375 : &m_problem);
845 :
846 : /* Handle failure to find a feasible path. */
847 6375 : if (m_best_epath == nullptr)
848 282 : return false;
849 :
850 : gcc_assert (m_best_epath);
851 :
852 : return true;
853 6375 : }
854 :
855 : unsigned
856 6622 : saved_diagnostic::get_epath_length () const
857 : {
858 6622 : gcc_assert (m_best_epath);
859 6622 : return m_best_epath->length ();
860 : }
861 :
862 : /* Record that OTHER (and its duplicates) are duplicates
863 : of this saved_diagnostic. */
864 :
865 : void
866 2064 : saved_diagnostic::add_duplicate (saved_diagnostic *other)
867 : {
868 2064 : gcc_assert (other);
869 2064 : m_duplicates.reserve (m_duplicates.length ()
870 2168 : + other->m_duplicates.length ()
871 : + 1);
872 2064 : m_duplicates.splice (other->m_duplicates);
873 2064 : other->m_duplicates.truncate (0);
874 2064 : m_duplicates.safe_push (other);
875 2064 : }
876 :
877 : /* Walk up the sedges of each of the two paths.
878 : If the two sequences of sedges do not perfectly correspond,
879 : then paths are incompatible.
880 : If there is at least one sedge that either cannot be paired up
881 : or its counterpart is not equal, then the paths are incompatible
882 : and this function returns FALSE.
883 : Otherwise return TRUE.
884 :
885 : Incompatible paths:
886 :
887 : <cond Y>
888 : / \
889 : / \
890 : true false
891 : | |
892 : ... ...
893 : | |
894 : ... stmt x
895 : |
896 : stmt x
897 :
898 : Both LHS_PATH and RHS_PATH final enodes should be
899 : over the same gimple statement. */
900 :
901 : static bool
902 70 : compatible_epath_p (const exploded_path *lhs_path,
903 : const exploded_path *rhs_path)
904 : {
905 70 : gcc_assert (lhs_path);
906 70 : gcc_assert (rhs_path);
907 70 : gcc_assert (rhs_path->length () > 0);
908 70 : gcc_assert (rhs_path->length () > 0);
909 70 : int lhs_eedge_idx = lhs_path->length () - 1;
910 70 : int rhs_eedge_idx = rhs_path->length () - 1;
911 70 : const exploded_edge *lhs_eedge;
912 70 : const exploded_edge *rhs_eedge;
913 :
914 1061 : while (lhs_eedge_idx >= 0 && rhs_eedge_idx >= 0)
915 : {
916 1130 : while (lhs_eedge_idx >= 0)
917 : {
918 : /* Find LHS_PATH's next superedge. */
919 1092 : lhs_eedge = lhs_path->m_edges[lhs_eedge_idx];
920 1092 : if (lhs_eedge->m_sedge)
921 : break;
922 : else
923 69 : lhs_eedge_idx--;
924 : }
925 1130 : while (rhs_eedge_idx >= 0)
926 : {
927 : /* Find RHS_PATH's next superedge. */
928 1092 : rhs_eedge = rhs_path->m_edges[rhs_eedge_idx];
929 1092 : if (rhs_eedge->m_sedge)
930 : break;
931 : else
932 69 : rhs_eedge_idx--;
933 : }
934 :
935 1061 : if (lhs_eedge->m_sedge && rhs_eedge->m_sedge)
936 : {
937 1023 : if (lhs_eedge->m_sedge != rhs_eedge->m_sedge)
938 : /* Both superedges do not match.
939 : Superedges are not dependent on the exploded path, so even
940 : different epaths will have similar sedges if they follow
941 : the same outcome of a conditional node. */
942 : return false;
943 :
944 991 : lhs_eedge_idx--;
945 991 : rhs_eedge_idx--;
946 991 : continue;
947 : }
948 38 : else if (lhs_eedge->m_sedge == nullptr && rhs_eedge->m_sedge == nullptr)
949 : /* Both paths were drained up entirely.
950 : No discriminant was found. */
951 : return true;
952 :
953 : /* A superedge was found for only one of the two paths. */
954 : return false;
955 : }
956 :
957 : /* A superedge was found for only one of the two paths. */
958 0 : if (lhs_eedge_idx >= 0 || rhs_eedge_idx >= 0)
959 : return false;
960 :
961 : /* Both paths were drained up entirely.
962 : No discriminant was found. */
963 : return true;
964 : }
965 :
966 :
967 : /* Return true if this diagnostic supercedes OTHER, and that OTHER should
968 : therefore not be emitted. */
969 :
970 : bool
971 25958 : saved_diagnostic::supercedes_p (const saved_diagnostic &other) const
972 : {
973 25958 : if (get_supernode () != other.get_supernode ())
974 : return false;
975 :
976 : /* return early if OTHER won't be superseded anyway. */
977 4907 : if (!m_d->supercedes_p (*other.m_d))
978 : return false;
979 :
980 : /* If the two saved_diagnostics' path are not compatible
981 : then they cannot supersede one another. */
982 70 : return compatible_epath_p (m_best_epath.get (), other.m_best_epath.get ());
983 : }
984 :
985 : /* Move any saved checker_events from this saved_diagnostic to
986 : the end of DST_PATH. */
987 :
988 : void
989 3991 : saved_diagnostic::add_any_saved_events (checker_path &dst_path)
990 : {
991 4432 : for (auto &event : m_saved_events)
992 : {
993 147 : dst_path.add_event (std::unique_ptr<checker_event> (event));
994 147 : event = nullptr;
995 : }
996 3991 : }
997 :
998 : /* Emit any pending notes owned by this diagnostic. */
999 :
1000 : void
1001 3923 : saved_diagnostic::emit_any_notes () const
1002 : {
1003 4441 : for (auto pn : m_notes)
1004 178 : pn->emit ();
1005 3923 : }
1006 :
1007 : /* For SARIF output, add additional properties to the "result" object
1008 : for this diagnostic.
1009 : This extra data is intended for use when debugging the analyzer. */
1010 :
1011 : void
1012 36 : saved_diagnostic::
1013 : maybe_add_sarif_properties (diagnostics::sarif_object &result_obj) const
1014 : {
1015 36 : auto &props = result_obj.get_or_create_properties ();
1016 : #define PROPERTY_PREFIX "gcc/analyzer/saved_diagnostic/"
1017 36 : if (m_sm)
1018 16 : props.set_string (PROPERTY_PREFIX "sm", m_sm->get_name ());
1019 36 : props.set (PROPERTY_PREFIX "ploc", m_ploc.to_json ());
1020 36 : if (m_var)
1021 16 : props.set (PROPERTY_PREFIX "var", tree_to_json (m_var));
1022 36 : if (m_sval)
1023 16 : props.set (PROPERTY_PREFIX "sval", m_sval->to_json ());
1024 36 : if (m_state)
1025 16 : props.set (PROPERTY_PREFIX "state", m_state->to_json ());
1026 : // TODO: m_best_epath
1027 36 : props.set_integer (PROPERTY_PREFIX "idx", m_idx);
1028 36 : if (m_duplicates.length () > 0)
1029 : {
1030 4 : auto duplicates_arr = std::make_unique<json::array> ();
1031 16 : for (auto iter : m_duplicates)
1032 : {
1033 4 : auto sd_obj = std::make_unique<diagnostics::sarif_object> ();
1034 4 : iter->maybe_add_sarif_properties (*sd_obj);
1035 4 : duplicates_arr->append (std::move (sd_obj));
1036 4 : }
1037 4 : props.set<json::array> (PROPERTY_PREFIX "duplicates",
1038 : std::move (duplicates_arr));
1039 4 : }
1040 : #undef PROPERTY_PREFIX
1041 :
1042 : #define PROPERTY_PREFIX "gcc/analyzer/pending_diagnostic/"
1043 36 : props.set_string (PROPERTY_PREFIX "kind", m_d->get_kind ());
1044 : #undef PROPERTY_PREFIX
1045 :
1046 : /* Potentially add pending_diagnostic-specific properties. */
1047 36 : m_d->maybe_add_sarif_properties (result_obj);
1048 36 : }
1049 :
1050 : /* State for building a checker_path from a particular exploded_path.
1051 : In particular, this precomputes reachability information: the set of
1052 : source enodes for which a path be found to the diagnostic enode. */
1053 :
1054 3991 : class path_builder
1055 : {
1056 : public:
1057 3991 : path_builder (const exploded_graph &eg,
1058 : const exploded_path &epath,
1059 : const feasibility_problem *problem,
1060 : const saved_diagnostic &sd)
1061 3991 : : m_eg (eg),
1062 3991 : m_diag_enode (epath.get_final_enode ()),
1063 3991 : m_sd (sd),
1064 3991 : m_reachability (eg, m_diag_enode),
1065 3991 : m_feasibility_problem (problem)
1066 3991 : {}
1067 :
1068 0 : const exploded_node *get_diag_node () const { return m_diag_enode; }
1069 :
1070 52454 : pending_diagnostic *get_pending_diagnostic () const
1071 : {
1072 207 : return m_sd.m_d.get ();
1073 : }
1074 :
1075 30557 : bool reachable_from_p (const exploded_node *src_enode) const
1076 : {
1077 61114 : return m_reachability.reachable_from_p (src_enode);
1078 : }
1079 :
1080 42084 : const extrinsic_state &get_ext_state () const { return m_eg.get_ext_state (); }
1081 :
1082 40314 : const feasibility_problem *get_feasibility_problem () const
1083 : {
1084 40314 : return m_feasibility_problem;
1085 : }
1086 :
1087 4444 : const state_machine *get_sm () const { return m_sd.m_sm; }
1088 :
1089 : private:
1090 : typedef reachability<eg_traits> enode_reachability;
1091 :
1092 : const exploded_graph &m_eg;
1093 :
1094 : /* The enode where the diagnostic occurs. */
1095 : const exploded_node *m_diag_enode;
1096 :
1097 : const saved_diagnostic &m_sd;
1098 :
1099 : /* Precompute all enodes from which the diagnostic is reachable. */
1100 : enode_reachability m_reachability;
1101 :
1102 : const feasibility_problem *m_feasibility_problem;
1103 : };
1104 :
1105 : /* class diagnostic_manager. */
1106 :
1107 : /* diagnostic_manager's ctor. */
1108 :
1109 3377 : diagnostic_manager::diagnostic_manager (logger *logger, engine *eng,
1110 3377 : int verbosity)
1111 3377 : : log_user (logger), m_eng (eng), m_verbosity (verbosity),
1112 3377 : m_num_disabled_diagnostics (0)
1113 : {
1114 3377 : }
1115 :
1116 : /* Queue pending_diagnostic D at ENODE for later emission.
1117 : Return true/false signifying if the diagnostic was actually added. */
1118 :
1119 : bool
1120 10478 : diagnostic_manager::add_diagnostic (const state_machine *sm,
1121 : pending_location &&ploc,
1122 : tree var,
1123 : const svalue *sval,
1124 : state_machine::state_t state,
1125 : std::unique_ptr<pending_diagnostic> d)
1126 : {
1127 10478 : LOG_FUNC (get_logger ());
1128 :
1129 : /* We must have an enode in order to be able to look for paths
1130 : through the exploded_graph to the diagnostic. */
1131 10478 : gcc_assert (ploc.m_enode);
1132 :
1133 : /* If this warning is ultimately going to be rejected by a -Wno-analyzer-*
1134 : flag, reject it now. */
1135 10478 : {
1136 10478 : location_t loc = ploc.m_event_loc_info.m_loc;
1137 10478 : loc = d->fixup_location (loc, true);
1138 10478 : int option = d->get_controlling_option ();
1139 10478 : if (!warning_enabled_at (loc, option))
1140 : {
1141 4103 : if (get_logger ())
1142 0 : get_logger ()->log ("rejecting disabled warning %qs",
1143 0 : d->get_kind ());
1144 4103 : m_num_disabled_diagnostics++;
1145 4103 : return false;
1146 : }
1147 : }
1148 :
1149 6375 : saved_diagnostic *sd
1150 : = new saved_diagnostic (sm,
1151 : std::move (ploc),
1152 : var,
1153 : sval,
1154 : state,
1155 : std::move (d),
1156 11194 : m_saved_diagnostics.length ());
1157 6375 : m_saved_diagnostics.safe_push (sd);
1158 6375 : sd->m_ploc.m_enode->add_diagnostic (sd);
1159 6375 : if (get_logger ())
1160 4 : log ("adding saved diagnostic %i at SN %i to EN %i: %qs",
1161 : sd->get_index (),
1162 2 : sd->get_supernode ()->m_id,
1163 2 : sd->m_ploc.m_enode->m_index,
1164 2 : sd->m_d->get_kind ());
1165 : return true;
1166 10478 : }
1167 :
1168 : /* Queue pending_diagnostic D at ENODE for later emission.
1169 : Return true/false signifying if the diagnostic was actually added.
1170 : Take ownership of D (or delete it). */
1171 :
1172 : bool
1173 3597 : diagnostic_manager::add_diagnostic (pending_location &&ploc,
1174 : std::unique_ptr<pending_diagnostic> d)
1175 : {
1176 3597 : gcc_assert (ploc.m_enode);
1177 3597 : return add_diagnostic (nullptr, std::move (ploc),
1178 3597 : NULL_TREE, nullptr, 0, std::move (d));
1179 : }
1180 :
1181 : /* Add PN to the most recent saved_diagnostic. */
1182 :
1183 : void
1184 194 : diagnostic_manager::add_note (std::unique_ptr<pending_note> pn)
1185 : {
1186 194 : LOG_FUNC (get_logger ());
1187 194 : gcc_assert (pn);
1188 :
1189 : /* Get most recent saved_diagnostic. */
1190 194 : gcc_assert (m_saved_diagnostics.length () > 0);
1191 194 : saved_diagnostic *sd = m_saved_diagnostics[m_saved_diagnostics.length () - 1];
1192 194 : sd->add_note (std::move (pn));
1193 194 : }
1194 :
1195 : /* Add EVENT to the most recent saved_diagnostic. */
1196 :
1197 : void
1198 159 : diagnostic_manager::add_event (std::unique_ptr<checker_event> event)
1199 : {
1200 159 : LOG_FUNC (get_logger ());
1201 159 : gcc_assert (event);
1202 :
1203 : /* Get most recent saved_diagnostic. */
1204 159 : gcc_assert (m_saved_diagnostics.length () > 0);
1205 159 : saved_diagnostic *sd = m_saved_diagnostics[m_saved_diagnostics.length () - 1];
1206 159 : sd->add_event (std::move (event));
1207 159 : }
1208 :
1209 : /* Return a new json::object of the form
1210 : {"diagnostics" : [obj for saved_diagnostic]}. */
1211 :
1212 : std::unique_ptr<json::object>
1213 0 : diagnostic_manager::to_json () const
1214 : {
1215 0 : auto dm_obj = std::make_unique<json::object> ();
1216 :
1217 0 : {
1218 0 : auto sd_arr = std::make_unique<json::array> ();
1219 0 : int i;
1220 0 : saved_diagnostic *sd;
1221 0 : FOR_EACH_VEC_ELT (m_saved_diagnostics, i, sd)
1222 0 : sd_arr->append (sd->to_json ());
1223 0 : dm_obj->set ("diagnostics", std::move (sd_arr));
1224 0 : }
1225 :
1226 0 : return dm_obj;
1227 : }
1228 :
1229 : /* A class for identifying sets of duplicated pending_diagnostic.
1230 :
1231 : We want to find the simplest saved_diagnostic amongst those that share a
1232 : dedupe_key. */
1233 :
1234 : class dedupe_key
1235 : {
1236 : public:
1237 6093 : dedupe_key (const saved_diagnostic &sd)
1238 6093 : : m_sd (sd),
1239 6093 : m_loc (sd.m_ploc.m_event_loc_info.m_loc)
1240 : {
1241 : }
1242 :
1243 60221 : hashval_t hash () const
1244 : {
1245 60221 : inchash::hash hstate;
1246 : // TODO: m_sd
1247 60221 : return hstate.end ();
1248 : }
1249 44107 : bool operator== (const dedupe_key &other) const
1250 : {
1251 44107 : return (m_sd == other.m_sd
1252 44107 : && m_loc == other.m_loc);
1253 : }
1254 :
1255 28039 : location_t get_location () const { return m_loc; }
1256 :
1257 : /* A qsort comparator for use by dedupe_winners::emit_best
1258 : to sort them into location_t order. */
1259 :
1260 : static int
1261 28039 : comparator (const void *p1, const void *p2)
1262 : {
1263 28039 : const dedupe_key *pk1 = *(const dedupe_key * const *)p1;
1264 28039 : const dedupe_key *pk2 = *(const dedupe_key * const *)p2;
1265 :
1266 28039 : location_t loc1 = pk1->get_location ();
1267 28039 : location_t loc2 = pk2->get_location ();
1268 :
1269 28039 : if (int cmp = linemap_compare_locations (line_table, loc2, loc1))
1270 : return cmp;
1271 1245 : if (int cmp = ((int)pk1->m_sd.get_epath_length ()
1272 1245 : - (int)pk2->m_sd.get_epath_length ()))
1273 : return cmp;
1274 602 : if (int cmp = strcmp (pk1->m_sd.m_d->get_kind (),
1275 602 : pk2->m_sd.m_d->get_kind ()))
1276 : return cmp;
1277 : return 0;
1278 : }
1279 :
1280 : const saved_diagnostic &m_sd;
1281 : location_t m_loc;
1282 : };
1283 :
1284 : /* Traits for use by dedupe_winners. */
1285 :
1286 : class dedupe_hash_map_traits
1287 : {
1288 : public:
1289 : typedef const dedupe_key *key_type;
1290 : typedef saved_diagnostic *value_type;
1291 : typedef saved_diagnostic *compare_type;
1292 :
1293 60221 : static inline hashval_t hash (const key_type &v)
1294 : {
1295 60221 : return v->hash ();
1296 : }
1297 44107 : static inline bool equal_keys (const key_type &k1, const key_type &k2)
1298 : {
1299 44107 : return *k1 == *k2;
1300 : }
1301 : template <typename T>
1302 : static inline void remove (T &)
1303 : {
1304 : // TODO
1305 : }
1306 : template <typename T>
1307 38 : static inline void mark_deleted (T &entry)
1308 : {
1309 38 : entry.m_key = reinterpret_cast<key_type> (1);
1310 : }
1311 : template <typename T>
1312 0 : static inline void mark_empty (T &entry)
1313 : {
1314 0 : entry.m_key = nullptr;
1315 : }
1316 : template <typename T>
1317 134780 : static inline bool is_deleted (const T &entry)
1318 : {
1319 134780 : return entry.m_key == reinterpret_cast<key_type> (1);
1320 : }
1321 : template <typename T>
1322 503837 : static inline bool is_empty (const T &entry)
1323 : {
1324 503837 : return entry.m_key == nullptr;
1325 : }
1326 : static const bool empty_zero_p = true;
1327 : };
1328 :
1329 : /* A class for deduplicating diagnostics and finding (and emitting) the
1330 : best saved_diagnostic within each partition. */
1331 :
1332 : class dedupe_winners
1333 : {
1334 : public:
1335 1556 : ~dedupe_winners ()
1336 : {
1337 : /* Delete all keys, but not the saved_diagnostics. */
1338 5547 : for (map_t::iterator iter = m_map.begin ();
1339 5547 : iter != m_map.end ();
1340 3991 : ++iter)
1341 3991 : delete (*iter).first;
1342 1556 : }
1343 :
1344 : /* Determine an exploded_path for SD using PF and, if it's feasible,
1345 : determine if SD is the best seen so far for its dedupe_key.
1346 : Record the winning SD for each dedupe_key. */
1347 :
1348 6375 : void add (logger *logger,
1349 : epath_finder *pf,
1350 : saved_diagnostic *sd)
1351 : {
1352 : /* Determine best epath for SD. */
1353 6375 : if (!sd->calc_best_epath (pf))
1354 282 : return;
1355 :
1356 6093 : const exploded_path *epath = sd->get_best_epath ();
1357 6093 : gcc_assert (epath);
1358 :
1359 : /* Now we have an exploded path, use it for pending_locations that are
1360 : affected by such things, and for deduplication. */
1361 6093 : if (sd->m_ploc.m_fixer_for_epath)
1362 1140 : sd->m_ploc.m_fixer_for_epath->fixup_for_epath (*epath, sd->m_ploc);
1363 :
1364 6093 : dedupe_key *key = new dedupe_key (*sd);
1365 6093 : if (saved_diagnostic **slot = m_map.get (key))
1366 : {
1367 2064 : if (logger)
1368 0 : logger->log ("already have this dedupe_key");
1369 :
1370 2064 : saved_diagnostic *cur_best_sd = *slot;
1371 :
1372 2064 : if (sd->get_epath_length () < cur_best_sd->get_epath_length ())
1373 : {
1374 : /* We've got a shorter path for the key; replace
1375 : the current candidate, marking it as a duplicate of SD. */
1376 145 : if (logger)
1377 0 : logger->log ("length %i is better than existing length %i;"
1378 : " taking over this dedupe_key",
1379 : sd->get_epath_length (),
1380 : cur_best_sd->get_epath_length ());
1381 145 : sd->add_duplicate (cur_best_sd);
1382 145 : *slot = sd;
1383 : }
1384 : else
1385 : /* We haven't beaten the current best candidate; add SD
1386 : as a duplicate of it. */
1387 : {
1388 1919 : if (logger)
1389 0 : logger->log ("length %i isn't better than existing length %i;"
1390 : " dropping this candidate",
1391 : sd->get_epath_length (),
1392 : cur_best_sd->get_epath_length ());
1393 1919 : cur_best_sd->add_duplicate (sd);
1394 : }
1395 2064 : delete key;
1396 : }
1397 : else
1398 : {
1399 : /* This is the first candidate for this key. */
1400 4029 : m_map.put (key, sd);
1401 4029 : if (logger)
1402 2 : logger->log ("first candidate for this dedupe_key");
1403 : }
1404 : }
1405 :
1406 : /* Handle interactions between the dedupe winners, so that some
1407 : diagnostics can supercede others (of different kinds).
1408 :
1409 : We want use-after-free to supercede use-of-unitialized-value,
1410 : so that if we have these at the same stmt, we don't emit
1411 : a use-of-uninitialized, just the use-after-free. */
1412 :
1413 1556 : void handle_interactions (diagnostic_manager *dm)
1414 : {
1415 1556 : LOG_SCOPE (dm->get_logger ());
1416 1556 : auto_vec<const dedupe_key *> superceded;
1417 5585 : for (auto outer : m_map)
1418 : {
1419 4029 : const saved_diagnostic *outer_sd = outer.second;
1420 59898 : for (auto inner : m_map)
1421 : {
1422 25958 : const saved_diagnostic *inner_sd = inner.second;
1423 25958 : if (inner_sd->supercedes_p (*outer_sd))
1424 : {
1425 38 : superceded.safe_push (outer.first);
1426 38 : if (dm->get_logger ())
1427 0 : dm->log ("sd[%i] \"%s\" superceded by sd[%i] \"%s\"",
1428 0 : outer_sd->get_index (), outer_sd->m_d->get_kind (),
1429 0 : inner_sd->get_index (), inner_sd->m_d->get_kind ());
1430 : break;
1431 : }
1432 : }
1433 : }
1434 1670 : for (auto iter : superceded)
1435 38 : m_map.remove (iter);
1436 1556 : }
1437 :
1438 : /* Emit the simplest diagnostic within each set. */
1439 :
1440 1556 : void emit_best (diagnostic_manager *dm,
1441 : const exploded_graph &eg)
1442 : {
1443 1556 : LOG_SCOPE (dm->get_logger ());
1444 :
1445 : /* Get keys into a vec for sorting. */
1446 1556 : auto_vec<const dedupe_key *> keys (m_map.elements ());
1447 1556 : for (map_t::iterator iter = m_map.begin ();
1448 5547 : iter != m_map.end ();
1449 3991 : ++iter)
1450 3991 : keys.quick_push ((*iter).first);
1451 :
1452 3063 : dm->log ("# keys after de-duplication: %i", keys.length ());
1453 :
1454 : /* Sort into a good emission order. */
1455 1556 : keys.qsort (dedupe_key::comparator);
1456 :
1457 : /* Emit the best saved_diagnostics for each key. */
1458 : int i;
1459 : const dedupe_key *key;
1460 7054 : FOR_EACH_VEC_ELT (keys, i, key)
1461 : {
1462 3991 : saved_diagnostic **slot = m_map.get (key);
1463 3991 : gcc_assert (*slot);
1464 3991 : saved_diagnostic *sd = *slot;
1465 3991 : dm->emit_saved_diagnostic (eg, *sd);
1466 : }
1467 1556 : }
1468 :
1469 : private:
1470 : /* This maps from each dedupe_key to a current best saved_diagnostic. */
1471 :
1472 : typedef hash_map<const dedupe_key *, saved_diagnostic *,
1473 : dedupe_hash_map_traits> map_t;
1474 : map_t m_map;
1475 : };
1476 :
1477 : /* Emit all saved diagnostics. */
1478 :
1479 : void
1480 3377 : diagnostic_manager::emit_saved_diagnostics (const exploded_graph &eg)
1481 : {
1482 3377 : LOG_SCOPE (get_logger ());
1483 3377 : auto_timevar tv (TV_ANALYZER_DIAGNOSTICS);
1484 4933 : log ("# saved diagnostics: %i", m_saved_diagnostics.length ());
1485 3377 : log ("# disabled diagnostics: %i", m_num_disabled_diagnostics);
1486 3377 : if (get_logger ())
1487 : {
1488 : unsigned i;
1489 : saved_diagnostic *sd;
1490 7 : FOR_EACH_VEC_ELT (m_saved_diagnostics, i, sd)
1491 2 : log ("[%i] sd: %qs at EN: %i, SN: %i",
1492 2 : i, sd->m_d->get_kind (), sd->m_ploc.m_enode->m_index,
1493 2 : sd->get_supernode ()->m_id);
1494 : }
1495 :
1496 3377 : if (m_saved_diagnostics.length () == 0)
1497 1821 : return;
1498 :
1499 : /* Compute the shortest_paths once, sharing it between all diagnostics. */
1500 1556 : epath_finder pf (eg);
1501 :
1502 : /* Iterate through all saved diagnostics, adding them to a dedupe_winners
1503 : instance. This partitions the saved diagnostics by dedupe_key,
1504 : generating exploded_paths for them, and retaining the best one in each
1505 : partition. */
1506 1556 : dedupe_winners best_candidates;
1507 :
1508 1556 : int i;
1509 1556 : saved_diagnostic *sd;
1510 9487 : FOR_EACH_VEC_ELT (m_saved_diagnostics, i, sd)
1511 6375 : best_candidates.add (get_logger (), &pf, sd);
1512 :
1513 1556 : best_candidates.handle_interactions (this);
1514 :
1515 : /* For each dedupe-key, call emit_saved_diagnostic on the "best"
1516 : saved_diagnostic. */
1517 1556 : best_candidates.emit_best (this, eg);
1518 3377 : }
1519 :
1520 : /* Custom subclass of diagnostics::metadata which, for SARIF output,
1521 : populates the property bag of the diagnostic's "result" object
1522 : with information from the saved_diagnostic and the
1523 : pending_diagnostic. */
1524 :
1525 3991 : class pending_diagnostic_metadata : public diagnostics::metadata
1526 : {
1527 : public:
1528 3991 : pending_diagnostic_metadata (const saved_diagnostic &sd)
1529 3991 : : m_sd (sd)
1530 : {
1531 : }
1532 :
1533 : void
1534 32 : maybe_add_sarif_properties (diagnostics::sarif_object &result_obj)
1535 : const override
1536 : {
1537 32 : m_sd.maybe_add_sarif_properties (result_obj);
1538 32 : }
1539 :
1540 : private:
1541 : const saved_diagnostic &m_sd;
1542 : };
1543 :
1544 : /* Given a saved_diagnostic SD with m_best_epath through EG,
1545 : create an checker_path of suitable events and use it to call
1546 : SD's underlying pending_diagnostic "emit" vfunc to emit a diagnostic. */
1547 :
1548 : void
1549 3991 : diagnostic_manager::emit_saved_diagnostic (const exploded_graph &eg,
1550 : saved_diagnostic &sd)
1551 : {
1552 3991 : LOG_SCOPE (get_logger ());
1553 3991 : log ("sd[%i]: %qs at SN: %i",
1554 3991 : sd.get_index (), sd.m_d->get_kind (), sd.get_supernode ()->m_id);
1555 5371 : log ("num dupes: %i", sd.get_num_dupes ());
1556 :
1557 3991 : const exploded_path *epath = sd.get_best_epath ();
1558 3991 : gcc_assert (epath);
1559 :
1560 : /* Precompute all enodes from which the diagnostic is reachable. */
1561 3991 : path_builder pb (eg, *epath, sd.get_feasibility_problem (), sd);
1562 :
1563 : /* This is the diagnostics::paths::path subclass that will be built for
1564 : the diagnostic. */
1565 3991 : checker_path emission_path (get_logical_location_manager (),
1566 : eg.get_ext_state (),
1567 3991 : get_logger ());
1568 :
1569 : /* Populate emission_path with a full description of EPATH. */
1570 3991 : build_emission_path (pb, *epath, &emission_path);
1571 :
1572 : /* Now prune it to just cover the most pertinent events. */
1573 3991 : prune_path (&emission_path, sd.m_sm, sd.m_sval, sd.m_state);
1574 :
1575 : /* Add any saved events to the path, giving contextual information
1576 : about what the analyzer was simulating as the diagnostic was
1577 : generated. These don't get pruned, as they are probably pertinent. */
1578 3991 : sd.add_any_saved_events (emission_path);
1579 :
1580 : /* Add a final event to the path, covering the diagnostic itself. */
1581 3991 : {
1582 3991 : const exploded_node *const enode = epath->get_final_enode ();
1583 3991 : sd.m_d->add_final_event (sd.m_sm, enode, sd.m_ploc.m_event_loc_info,
1584 : sd.m_var, sd.m_state, &emission_path);
1585 : }
1586 :
1587 : /* The "final" event might not be final; if the saved_diagnostic has a
1588 : trailing eedge stashed, add any events for it. This is for use
1589 : in handling longjmp, to show where a longjmp is rewinding to. */
1590 3991 : if (sd.m_trailing_eedge)
1591 4 : add_events_for_eedge (pb, *sd.m_trailing_eedge, &emission_path, nullptr);
1592 :
1593 3991 : emission_path.inject_any_inlined_call_events (get_logger ());
1594 :
1595 3991 : emission_path.prepare_for_emission (sd.m_d.get ());
1596 :
1597 3991 : location_t loc = sd.m_ploc.m_event_loc_info.m_loc;
1598 3991 : loc = sd.m_d->fixup_location (loc, true);
1599 :
1600 : /* Allow the pending_diagnostic to fix up the locations of events. */
1601 3991 : emission_path.fixup_locations (sd.m_d.get ());
1602 :
1603 3991 : gcc_rich_location rich_loc (loc);
1604 3991 : rich_loc.set_path (&emission_path);
1605 :
1606 3991 : auto_diagnostic_group d;
1607 3991 : auto_cfun sentinel (sd.get_supernode ()->m_fun);
1608 3991 : pending_diagnostic_metadata m (sd);
1609 3991 : diagnostic_emission_context diag_ctxt (sd, rich_loc, m, get_logger ());
1610 3991 : if (sd.m_d->emit (diag_ctxt))
1611 : {
1612 3923 : sd.emit_any_notes ();
1613 :
1614 3923 : unsigned num_dupes = sd.get_num_dupes ();
1615 3923 : if (flag_analyzer_show_duplicate_count && num_dupes > 0)
1616 4 : inform_n (loc, num_dupes,
1617 : "%i duplicate", "%i duplicates",
1618 : num_dupes);
1619 3923 : if (flag_dump_analyzer_exploded_paths)
1620 : {
1621 0 : auto_timevar tv (TV_ANALYZER_DUMP);
1622 0 : pretty_printer pp;
1623 0 : pp_printf (&pp, "%s.%i.%s.epath.txt",
1624 0 : dump_base_name, sd.get_index (), sd.m_d->get_kind ());
1625 0 : char *filename = xstrdup (pp_formatted_text (&pp));
1626 0 : epath->dump_to_file (filename, eg.get_ext_state ());
1627 0 : inform (loc, "exploded path written to %qs", filename);
1628 0 : free (filename);
1629 0 : }
1630 : }
1631 3991 : }
1632 :
1633 : const diagnostics::logical_locations::manager &
1634 3991 : diagnostic_manager::get_logical_location_manager () const
1635 : {
1636 3991 : gcc_assert (global_dc);
1637 3991 : auto mgr = global_dc->get_logical_location_manager ();
1638 3991 : gcc_assert (mgr);
1639 3991 : return *mgr;
1640 : }
1641 :
1642 : /* Emit a "path" of events to EMISSION_PATH describing the exploded path
1643 : EPATH within EG. */
1644 :
1645 : void
1646 3991 : diagnostic_manager::build_emission_path (const path_builder &pb,
1647 : const exploded_path &epath,
1648 : checker_path *emission_path) const
1649 : {
1650 3991 : LOG_SCOPE (get_logger ());
1651 :
1652 3991 : interesting_t interest;
1653 3991 : pb.get_pending_diagnostic ()->mark_interesting_stuff (&interest);
1654 :
1655 : /* Add region creation events for any globals of interest, at the
1656 : beginning of the path. */
1657 3991 : {
1658 7919 : for (auto reg : interest.m_region_creation)
1659 1328 : switch (reg->get_memory_space ())
1660 : {
1661 1112 : default:
1662 1112 : continue;
1663 216 : case MEMSPACE_CODE:
1664 216 : case MEMSPACE_GLOBALS:
1665 216 : case MEMSPACE_READONLY_DATA:
1666 216 : {
1667 216 : const region *base_reg = reg->get_base_region ();
1668 216 : if (tree decl = base_reg->maybe_get_decl ())
1669 207 : if (DECL_P (decl)
1670 207 : && useful_location_p (DECL_SOURCE_LOCATION (decl)))
1671 : {
1672 207 : emission_path->add_region_creation_events
1673 207 : (pb.get_pending_diagnostic (),
1674 : reg, nullptr,
1675 207 : event_loc_info (DECL_SOURCE_LOCATION (decl),
1676 : NULL_TREE,
1677 207 : 0),
1678 207 : m_verbosity > 3);
1679 : }
1680 : }
1681 1112 : }
1682 : }
1683 :
1684 : /* Walk EPATH, adding events as appropriate. */
1685 46071 : for (unsigned i = 0; i < epath.m_edges.length (); i++)
1686 : {
1687 42080 : const exploded_edge *eedge = epath.m_edges[i];
1688 42080 : add_events_for_eedge (pb, *eedge, emission_path, &interest);
1689 : }
1690 3991 : add_event_on_final_node (pb, epath.get_final_enode (),
1691 : emission_path, &interest);
1692 3991 : }
1693 :
1694 : /* Emit a region_creation_event when requested on the last statement in
1695 : the path.
1696 :
1697 : If a region_creation_event should be emitted on the last statement of the
1698 : path, we need to peek to the successors to get whether the final enode
1699 : created a region.
1700 : */
1701 :
1702 : void
1703 3991 : diagnostic_manager::add_event_on_final_node (const path_builder &pb,
1704 : const exploded_node *final_enode,
1705 : checker_path *emission_path,
1706 : interesting_t *interest) const
1707 : {
1708 3991 : const program_point &src_point = final_enode->get_point ();
1709 3991 : const int src_stack_depth = src_point.get_stack_depth ();
1710 3991 : const program_state &src_state = final_enode->get_state ();
1711 3991 : const region_model *src_model = src_state.m_region_model;
1712 :
1713 3991 : unsigned j;
1714 3991 : exploded_edge *e;
1715 7189 : FOR_EACH_VEC_ELT (final_enode->m_succs, j, e)
1716 : {
1717 3275 : exploded_node *dst = e->m_dest;
1718 3275 : const program_state &dst_state = dst->get_state ();
1719 3275 : const region_model *dst_model = dst_state.m_region_model;
1720 3275 : if (src_model->get_dynamic_extents ()
1721 3275 : != dst_model->get_dynamic_extents ())
1722 : {
1723 : unsigned i;
1724 : const region *reg;
1725 : bool emitted = false;
1726 456 : FOR_EACH_VEC_ELT (interest->m_region_creation, i, reg)
1727 : {
1728 92 : const region *base_reg = reg->get_base_region ();
1729 92 : const svalue *old_extents
1730 92 : = src_model->get_dynamic_extents (base_reg);
1731 92 : const svalue *new_extents
1732 92 : = dst_model->get_dynamic_extents (base_reg);
1733 92 : if (old_extents == nullptr && new_extents != nullptr)
1734 81 : switch (base_reg->get_kind ())
1735 : {
1736 : default:
1737 : break;
1738 77 : case RK_HEAP_ALLOCATED:
1739 77 : case RK_ALLOCA:
1740 77 : emission_path->add_region_creation_events
1741 154 : (pb.get_pending_diagnostic (),
1742 : reg,
1743 : dst_model,
1744 77 : event_loc_info (src_point.get_location (),
1745 : src_point.get_fndecl (),
1746 154 : src_stack_depth),
1747 : false);
1748 77 : emitted = true;
1749 77 : break;
1750 : }
1751 : }
1752 364 : if (emitted)
1753 : break;
1754 : }
1755 : }
1756 3991 : }
1757 :
1758 : /* Subclass of state_change_visitor that creates state_change_event
1759 : instances. */
1760 :
1761 42084 : class state_change_event_creator : public state_change_visitor
1762 : {
1763 : public:
1764 42084 : state_change_event_creator (const path_builder &pb,
1765 : const exploded_edge &eedge,
1766 : checker_path *emission_path)
1767 42084 : : m_pb (pb),
1768 42084 : m_eedge (eedge),
1769 42084 : m_emission_path (emission_path)
1770 : {}
1771 :
1772 98 : bool on_global_state_change (const state_machine &sm,
1773 : state_machine::state_t src_sm_val,
1774 : state_machine::state_t dst_sm_val)
1775 : final override
1776 : {
1777 98 : if (&sm != m_pb.get_sm ())
1778 : return false;
1779 55 : const exploded_node *src_node = m_eedge.m_src;
1780 55 : const exploded_node *dst_node = m_eedge.m_dest;
1781 55 : const gimple *stmt = m_eedge.maybe_get_stmt ();
1782 55 : const program_state &dst_state = dst_node->get_state ();
1783 :
1784 55 : m_emission_path->add_event
1785 55 : (std::make_unique<state_change_event> (m_eedge.m_src,
1786 : stmt,
1787 : sm,
1788 110 : nullptr,
1789 : src_sm_val,
1790 : dst_sm_val,
1791 55 : nullptr,
1792 : dst_state,
1793 : src_node));
1794 55 : return false;
1795 : }
1796 :
1797 4346 : bool on_state_change (const state_machine &sm,
1798 : state_machine::state_t src_sm_val,
1799 : state_machine::state_t dst_sm_val,
1800 : const svalue *sval,
1801 : const svalue *dst_origin_sval) final override
1802 : {
1803 4346 : if (&sm != m_pb.get_sm ())
1804 : return false;
1805 :
1806 3298 : const exploded_node *src_node = m_eedge.m_src;
1807 3298 : const exploded_node *dst_node = m_eedge.m_dest;
1808 3298 : const gimple *stmt = m_eedge.maybe_get_stmt ();
1809 3298 : const program_state &dst_state = dst_node->get_state ();
1810 :
1811 3298 : m_emission_path->add_event
1812 3298 : (std::make_unique<state_change_event> (m_eedge.m_src,
1813 : stmt,
1814 : sm,
1815 : sval,
1816 : src_sm_val,
1817 : dst_sm_val,
1818 : dst_origin_sval,
1819 : dst_state,
1820 : src_node));
1821 3298 : return false;
1822 : }
1823 :
1824 : const path_builder &m_pb;
1825 : const exploded_edge &m_eedge;
1826 : checker_path *m_emission_path;
1827 : };
1828 :
1829 : /* Compare SRC_STATE and DST_STATE (which use EXT_STATE), and call
1830 : VISITOR's on_state_change for every sm-state change that occurs
1831 : to a tree, and on_global_state_change for every global state change
1832 : that occurs.
1833 :
1834 : This determines the state changes that ought to be reported to
1835 : the user: a combination of the effects of changes to sm_state_map
1836 : (which maps svalues to sm-states), and of region_model changes
1837 : (which map trees to svalues).
1838 :
1839 : Bail out early and return true if any call to on_global_state_change
1840 : or on_state_change returns true, otherwise return false.
1841 :
1842 : This is split out to make it easier to experiment with changes to
1843 : exploded_node granularity (so that we can observe what state changes
1844 : lead to state_change_events being emitted). */
1845 :
1846 : bool
1847 42084 : for_each_state_change (const program_state &src_state,
1848 : const program_state &dst_state,
1849 : const extrinsic_state &ext_state,
1850 : state_change_visitor *visitor)
1851 : {
1852 84168 : gcc_assert (src_state.m_checker_states.length ()
1853 : == ext_state.get_num_checkers ());
1854 84168 : gcc_assert (dst_state.m_checker_states.length ()
1855 : == ext_state.get_num_checkers ());
1856 335140 : for (unsigned i = 0; i < ext_state.get_num_checkers (); i++)
1857 : {
1858 293056 : const state_machine &sm = ext_state.get_sm (i);
1859 293056 : const sm_state_map &src_smap = *src_state.m_checker_states[i];
1860 293056 : const sm_state_map &dst_smap = *dst_state.m_checker_states[i];
1861 :
1862 : /* Add events for any global state changes. */
1863 293056 : if (src_smap.get_global_state () != dst_smap.get_global_state ())
1864 98 : if (visitor->on_global_state_change (sm,
1865 : src_smap.get_global_state (),
1866 : dst_smap.get_global_state ()))
1867 : return true;
1868 :
1869 : /* Add events for per-svalue state changes. */
1870 328067 : for (sm_state_map::iterator_t iter = dst_smap.begin ();
1871 621123 : iter != dst_smap.end ();
1872 35011 : ++iter)
1873 : {
1874 35011 : const svalue *sval = (*iter).first;
1875 35011 : state_machine::state_t dst_sm_val = (*iter).second.m_state;
1876 35011 : state_machine::state_t src_sm_val
1877 35011 : = src_smap.get_state (sval, ext_state);
1878 35011 : if (dst_sm_val != src_sm_val)
1879 : {
1880 4346 : const svalue *origin_sval = (*iter).second.m_origin;
1881 4346 : if (visitor->on_state_change (sm, src_sm_val, dst_sm_val,
1882 : sval, origin_sval))
1883 0 : return true;
1884 : }
1885 : }
1886 : }
1887 : return false;
1888 : }
1889 :
1890 : /* Subroutine of diagnostic_manager::build_emission_path.
1891 : Add any events for EEDGE to EMISSION_PATH. */
1892 :
1893 : void
1894 42084 : diagnostic_manager::add_events_for_eedge (const path_builder &pb,
1895 : const exploded_edge &eedge,
1896 : checker_path *emission_path,
1897 : interesting_t *interest) const
1898 : {
1899 42084 : const exploded_node *src_node = eedge.m_src;
1900 42084 : const program_point &src_point = src_node->get_point ();
1901 42084 : const int src_stack_depth = src_point.get_stack_depth ();
1902 42084 : const exploded_node *dst_node = eedge.m_dest;
1903 42084 : const program_point &dst_point = dst_node->get_point ();
1904 42084 : const int dst_stack_depth = dst_point.get_stack_depth ();
1905 42084 : if (get_logger ())
1906 : {
1907 13 : get_logger ()->start_log_line ();
1908 13 : pretty_printer *pp = get_logger ()->get_printer ();
1909 13 : pp_printf (pp, "EN %i -> EN %i: ",
1910 13 : eedge.m_src->m_index,
1911 13 : eedge.m_dest->m_index);
1912 13 : src_point.print (pp, format (false));
1913 13 : pp_string (pp, "-> ");
1914 13 : dst_point.print (pp, format (false));
1915 13 : get_logger ()->end_log_line ();
1916 : }
1917 42084 : const program_state &src_state = src_node->get_state ();
1918 42084 : const program_state &dst_state = dst_node->get_state ();
1919 :
1920 : /* Add state change events for the states that have changed.
1921 : We add these before events for superedges, so that if we have a
1922 : state_change_event due to following an edge, we'll get this sequence
1923 : of events:
1924 :
1925 : | if (!ptr)
1926 : | ~
1927 : | |
1928 : | (1) assuming 'ptr' is non-NULL (state_change_event)
1929 : | (2) following 'false' branch... (start_cfg_edge_event)
1930 : ...
1931 : | do_something (ptr);
1932 : | ~~~~~~~~~~~~~^~~~~
1933 : | |
1934 : | (3) ...to here (end_cfg_edge_event). */
1935 42084 : state_change_event_creator visitor (pb, eedge, emission_path);
1936 42084 : for_each_state_change (src_state, dst_state, pb.get_ext_state (),
1937 : &visitor);
1938 :
1939 : /* Give diagnostics an opportunity to inject extra events, or
1940 : to override the rest of this function. */
1941 42084 : pending_diagnostic *pd = pb.get_pending_diagnostic ();
1942 42084 : if (pd->maybe_add_custom_events_for_eedge (eedge, emission_path))
1943 : return;
1944 :
1945 : /* Allow non-standard edges to add events, e.g. when rewinding from
1946 : longjmp to a setjmp. */
1947 41107 : if (eedge.m_custom_info)
1948 2320 : eedge.m_custom_info->add_events_to_path (emission_path, eedge, *pd);
1949 :
1950 : /* Don't add events for insignificant edges at verbosity levels below 3. */
1951 41107 : if (m_verbosity < 3)
1952 40882 : if (!significant_edge_p (pb, eedge))
1953 : return;
1954 :
1955 : /* Add events for operations. */
1956 40310 : if (eedge.m_sedge)
1957 35177 : if (auto op = eedge.m_sedge->get_op ())
1958 25872 : op->add_any_events_for_eedge (eedge, *emission_path);
1959 :
1960 : /* Add events for function entry. */
1961 40310 : if (dst_point.get_supernode ()->entry_p ())
1962 : {
1963 5104 : pb.get_pending_diagnostic ()->add_function_entry_event
1964 5104 : (eedge, emission_path);
1965 : /* Create region_creation_events for on-stack regions within
1966 : this frame. */
1967 5104 : if (interest)
1968 : {
1969 : unsigned i;
1970 : const region *reg;
1971 6572 : FOR_EACH_VEC_ELT (interest->m_region_creation, i, reg)
1972 1468 : if (const frame_region *frame = reg->maybe_get_frame_region ())
1973 1948 : if (frame->get_fndecl () == dst_point.get_fndecl ())
1974 : {
1975 855 : const region *base_reg = reg->get_base_region ();
1976 855 : if (tree decl = base_reg->maybe_get_decl ())
1977 754 : if (DECL_P (decl)
1978 754 : && useful_location_p (DECL_SOURCE_LOCATION (decl)))
1979 : {
1980 750 : emission_path->add_region_creation_events
1981 1500 : (pb.get_pending_diagnostic (),
1982 750 : reg, dst_state.m_region_model,
1983 750 : event_loc_info (DECL_SOURCE_LOCATION (decl),
1984 : dst_point.get_fndecl (),
1985 750 : dst_stack_depth),
1986 750 : m_verbosity > 3);
1987 : }
1988 : }
1989 : }
1990 : }
1991 :
1992 : /* Look for changes in dynamic extents, which will identify
1993 : the creation of heap-based regions and alloca regions. */
1994 40310 : if (interest)
1995 : {
1996 40306 : const region_model *src_model = src_state.m_region_model;
1997 40306 : const region_model *dst_model = dst_state.m_region_model;
1998 40306 : if (src_model->get_dynamic_extents ()
1999 40306 : != dst_model->get_dynamic_extents ())
2000 : {
2001 : unsigned i;
2002 : const region *reg;
2003 2389 : FOR_EACH_VEC_ELT (interest->m_region_creation, i, reg)
2004 : {
2005 421 : const region *base_reg = reg->get_base_region ();
2006 421 : const svalue *old_extents
2007 421 : = src_model->get_dynamic_extents (base_reg);
2008 421 : const svalue *new_extents
2009 421 : = dst_model->get_dynamic_extents (base_reg);
2010 421 : if (old_extents == nullptr && new_extents != nullptr)
2011 277 : switch (base_reg->get_kind ())
2012 : {
2013 : default:
2014 : break;
2015 241 : case RK_HEAP_ALLOCATED:
2016 241 : case RK_ALLOCA:
2017 241 : emission_path->add_region_creation_events
2018 241 : (pb.get_pending_diagnostic (),
2019 : reg, dst_model,
2020 241 : event_loc_info (src_point.get_location (),
2021 : src_point.get_fndecl (),
2022 482 : src_stack_depth),
2023 241 : m_verbosity > 3);
2024 241 : break;
2025 : }
2026 : }
2027 : }
2028 : }
2029 :
2030 40310 : if (pb.get_feasibility_problem ()
2031 40310 : && &pb.get_feasibility_problem ()->m_eedge == &eedge)
2032 : {
2033 4 : pretty_printer pp;
2034 4 : pp_format_decoder (&pp) = default_tree_printer;
2035 4 : pp_string (&pp,
2036 : "this path would have been rejected as infeasible"
2037 : " at this edge: ");
2038 4 : pb.get_feasibility_problem ()->dump_to_pp (&pp);
2039 4 : emission_path->add_event
2040 4 : (std::make_unique<precanned_custom_event>
2041 4 : (event_loc_info (dst_point.get_location (),
2042 : dst_point.get_fndecl (),
2043 8 : dst_stack_depth),
2044 4 : pp_formatted_text (&pp)));
2045 4 : }
2046 42084 : }
2047 :
2048 : /* Return true if EEDGE is a significant edge in the path to the diagnostic
2049 : for PB.
2050 :
2051 : Consider all of the sibling out-eedges from the same source enode
2052 : as EEDGE.
2053 : If there's no path from the destinations of those eedges to the
2054 : diagnostic enode, then we have to take this eedge and thus it's
2055 : significant.
2056 :
2057 : Conversely if there is a path from the destination of any other sibling
2058 : eedge to the diagnostic enode, then this edge is insignificant.
2059 :
2060 : Example 1: redundant if-else:
2061 :
2062 : (A) if (...) A
2063 : (B) ... / \
2064 : else B C
2065 : (C) ... \ /
2066 : (D) [DIAGNOSTIC] D
2067 :
2068 : D is reachable by either B or C, so neither of these edges
2069 : are significant.
2070 :
2071 : Example 2: pertinent if-else:
2072 :
2073 : (A) if (...) A
2074 : (B) ... / \
2075 : else B C
2076 : (C) [NECESSARY CONDITION] | |
2077 : (D) [POSSIBLE DIAGNOSTIC] D1 D2
2078 :
2079 : D becomes D1 and D2 in the exploded graph, where the diagnostic occurs
2080 : at D2. D2 is only reachable via C, so the A -> C edge is significant.
2081 :
2082 : Example 3: redundant loop:
2083 :
2084 : (A) while (...) +-->A
2085 : (B) ... | / \
2086 : (C) ... +-B C
2087 : (D) [DIAGNOSTIC] |
2088 : D
2089 :
2090 : D is reachable from both B and C, so the A->C edge is not significant. */
2091 :
2092 : bool
2093 40882 : diagnostic_manager::significant_edge_p (const path_builder &pb,
2094 : const exploded_edge &eedge) const
2095 : {
2096 40882 : int i;
2097 40882 : exploded_edge *sibling;
2098 111147 : FOR_EACH_VEC_ELT (eedge.m_src->m_succs, i, sibling)
2099 : {
2100 71062 : if (sibling == &eedge)
2101 40505 : continue;
2102 30557 : if (pb.reachable_from_p (sibling->m_dest))
2103 : {
2104 797 : if (get_logger ())
2105 0 : get_logger ()->log (" edge EN: %i -> EN: %i is insignificant as"
2106 : " EN: %i is also reachable via"
2107 : " EN: %i -> EN: %i",
2108 0 : eedge.m_src->m_index, eedge.m_dest->m_index,
2109 0 : pb.get_diag_node ()->m_index,
2110 0 : sibling->m_src->m_index,
2111 : sibling->m_dest->m_index);
2112 797 : return false;
2113 : }
2114 : }
2115 :
2116 : return true;
2117 : }
2118 :
2119 : /* Prune PATH, based on the verbosity level, to the most pertinent
2120 : events for a diagnostic that involves VAR ending in state STATE
2121 : (for state machine SM).
2122 :
2123 : PATH is updated in place, and the redundant checker_events are deleted.
2124 :
2125 : As well as deleting events, call record_critical_state on events in
2126 : which state critical to the pending_diagnostic is being handled; see
2127 : the comment for diagnostic_manager::prune_for_sm_diagnostic. */
2128 :
2129 : void
2130 3991 : diagnostic_manager::prune_path (checker_path *path,
2131 : const state_machine *sm,
2132 : const svalue *sval,
2133 : state_machine::state_t state) const
2134 : {
2135 3991 : LOG_FUNC (get_logger ());
2136 3991 : path->maybe_log (get_logger (), "path");
2137 3991 : prune_for_sm_diagnostic (path, sm, sval, state);
2138 3991 : prune_interproc_events (path);
2139 3991 : if (! flag_analyzer_show_events_in_system_headers)
2140 3989 : prune_system_headers (path);
2141 3991 : consolidate_conditions (path);
2142 3991 : consolidate_unwind_events (path);
2143 3991 : finish_pruning (path);
2144 3991 : path->maybe_log (get_logger (), "pruned");
2145 3991 : }
2146 :
2147 : /* A cheap test to determine if EXPR can be the expression of interest in
2148 : an sm-diagnostic, so that we can reject cases where we have a non-lvalue.
2149 : We don't have always have a model when calling this, so we can't use
2150 : tentative_region_model_context, so there can be false positives. */
2151 :
2152 : static bool
2153 0 : can_be_expr_of_interest_p (tree expr)
2154 : {
2155 0 : if (!expr)
2156 : return false;
2157 :
2158 : /* Reject constants. */
2159 0 : if (CONSTANT_CLASS_P (expr))
2160 0 : return false;
2161 :
2162 : /* Otherwise assume that it can be an lvalue. */
2163 : return true;
2164 : }
2165 :
2166 : /* First pass of diagnostic_manager::prune_path: apply verbosity level,
2167 : pruning unrelated state change events.
2168 :
2169 : Iterate backwards through PATH, skipping state change events that aren't
2170 : VAR but update the pertinent VAR when state-copying occurs.
2171 :
2172 : As well as deleting events, call record_critical_state on events in
2173 : which state critical to the pending_diagnostic is being handled, so
2174 : that the event's get_desc vfunc can potentially supply a more precise
2175 : description of the event to the user.
2176 : e.g. improving
2177 : "calling 'foo' from 'bar'"
2178 : to
2179 : "passing possibly-NULL pointer 'ptr' to 'foo' from 'bar' as param 1"
2180 : when the diagnostic relates to later dereferencing 'ptr'. */
2181 :
2182 : void
2183 3991 : diagnostic_manager::prune_for_sm_diagnostic (checker_path *path,
2184 : const state_machine *sm,
2185 : const svalue *sval,
2186 : state_machine::state_t state) const
2187 : {
2188 3991 : int idx = path->num_events () - 1;
2189 67385 : while (idx >= 0 && idx < (signed)path->num_events ())
2190 : {
2191 31697 : checker_event *base_event = path->get_checker_event (idx);
2192 31697 : if (get_logger ())
2193 : {
2194 6 : if (sm)
2195 : {
2196 0 : if (sval)
2197 : {
2198 0 : label_text sval_desc = sval->get_desc ();
2199 0 : log ("considering event %i (%s), with sval: %qs, state: %qs",
2200 : idx, event_kind_to_string (base_event->get_kind ()),
2201 : sval_desc.get (), state->get_name ());
2202 0 : }
2203 : else
2204 0 : log ("considering event %i (%s), with global state: %qs",
2205 : idx, event_kind_to_string (base_event->get_kind ()),
2206 : state->get_name ());
2207 : }
2208 : else
2209 6 : log ("considering event %i", idx);
2210 : }
2211 :
2212 31697 : switch (base_event->get_kind ())
2213 : {
2214 0 : default:
2215 0 : gcc_unreachable ();
2216 :
2217 0 : case event_kind::debug:
2218 0 : if (m_verbosity < 4)
2219 : {
2220 0 : log ("filtering event %i: debug event", idx);
2221 0 : path->delete_event (idx);
2222 : }
2223 : break;
2224 :
2225 : case event_kind::custom:
2226 : /* Don't filter custom events. */
2227 : break;
2228 :
2229 13613 : case event_kind::stmt:
2230 13613 : {
2231 13613 : if (m_verbosity < 4)
2232 : {
2233 13613 : log ("filtering event %i: statement event", idx);
2234 13613 : path->delete_event (idx);
2235 : }
2236 : }
2237 : break;
2238 :
2239 : case event_kind::region_creation:
2240 : /* Don't filter these. */
2241 : break;
2242 :
2243 5104 : case event_kind::function_entry:
2244 5104 : if (m_verbosity < 1)
2245 : {
2246 33 : log ("filtering event %i: function entry", idx);
2247 33 : path->delete_event (idx);
2248 : }
2249 : break;
2250 :
2251 3772 : case event_kind::state_change:
2252 3772 : {
2253 3772 : state_change_event *state_change = (state_change_event *)base_event;
2254 3772 : gcc_assert (state_change->m_dst_state.m_region_model);
2255 :
2256 3772 : if (state_change->m_sval == sval)
2257 : {
2258 2135 : if (state_change->m_origin)
2259 : {
2260 0 : if (get_logger ())
2261 : {
2262 0 : label_text sval_desc = sval->get_desc ();
2263 0 : label_text origin_sval_desc
2264 0 : = state_change->m_origin->get_desc ();
2265 0 : log ("event %i:"
2266 : " switching var of interest from %qs to %qs",
2267 : idx, sval_desc.get (),
2268 : origin_sval_desc.get ());
2269 0 : }
2270 0 : sval = state_change->m_origin;
2271 : }
2272 2135 : log ("event %i: switching state of interest from %qs to %qs",
2273 2135 : idx, state_change->m_to->get_name (),
2274 2135 : state_change->m_from->get_name ());
2275 2135 : state = state_change->m_from;
2276 : }
2277 1637 : else if (m_verbosity < 4)
2278 : {
2279 1637 : if (get_logger ())
2280 : {
2281 0 : if (state_change->m_sval)
2282 : {
2283 0 : label_text change_sval_desc
2284 0 : = state_change->m_sval->get_desc ();
2285 0 : if (sval)
2286 : {
2287 0 : label_text sval_desc = sval->get_desc ();
2288 0 : log ("filtering event %i:"
2289 : " state change to %qs unrelated to %qs",
2290 : idx, change_sval_desc.get (),
2291 : sval_desc.get ());
2292 0 : }
2293 : else
2294 0 : log ("filtering event %i: state change to %qs",
2295 : idx, change_sval_desc.get ());
2296 0 : }
2297 : else
2298 0 : log ("filtering event %i: global state change", idx);
2299 : }
2300 1637 : path->delete_event (idx);
2301 : }
2302 : }
2303 : break;
2304 :
2305 2607 : case event_kind::start_cfg_edge:
2306 2607 : {
2307 2607 : cfg_edge_event *event = (cfg_edge_event *)base_event;
2308 :
2309 : /* TODO: is this edge significant to var?
2310 : See if var can be in other states in the dest, but not
2311 : in other states in the src?
2312 : Must have multiple sibling edges. */
2313 :
2314 2607 : if (event->should_filter_p (m_verbosity))
2315 : {
2316 36 : log ("filtering events %i and %i: CFG edge", idx, idx + 1);
2317 36 : path->delete_event (idx);
2318 : /* Also delete the corresponding event_kind::end_cfg_edge. */
2319 36 : gcc_assert (path->get_checker_event (idx)->get_kind ()
2320 : == event_kind::end_cfg_edge);
2321 36 : path->delete_event (idx);
2322 : }
2323 : }
2324 : break;
2325 :
2326 : case event_kind::end_cfg_edge:
2327 : /* These come in pairs with event_kind::start_cfg_edge events and are
2328 : filtered when their start event is filtered. */
2329 : break;
2330 :
2331 : case event_kind::catch_:
2332 : case event_kind::throw_:
2333 : case event_kind::unwind:
2334 : /* Don't filter these. */
2335 : break;
2336 :
2337 1193 : case event_kind::call_:
2338 1193 : {
2339 1193 : call_event *event = (call_event *)base_event;
2340 1193 : const region_model *callee_model
2341 1193 : = event->m_eedge.m_dest->get_state ().m_region_model;
2342 1193 : const region_model *caller_model
2343 1193 : = event->m_eedge.m_src->get_state ().m_region_model;
2344 1193 : tree callee_var = callee_model->get_representative_tree (sval);
2345 1193 : callsite_expr expr;
2346 :
2347 1193 : tree caller_var;
2348 1193 : if (auto op = event->get_call_and_return_op ())
2349 : {
2350 1193 : tree callee_fndecl
2351 1193 : = event->m_eedge.m_dest->get_point ().get_fndecl ();
2352 1193 : caller_var
2353 1193 : = op->map_expr_from_callee_to_caller (callee_fndecl,
2354 : callee_var,
2355 : &expr);
2356 : }
2357 : else
2358 0 : caller_var = caller_model->get_representative_tree (sval);
2359 :
2360 1193 : if (caller_var)
2361 : {
2362 215 : if (get_logger ())
2363 : {
2364 0 : label_text sval_desc = sval->get_desc ();
2365 0 : log ("event %i:"
2366 : " recording critical state for %qs at call"
2367 : " from %qE in callee to %qE in caller",
2368 : idx, sval_desc.get (), callee_var, caller_var);
2369 0 : }
2370 215 : if (expr.param_p ())
2371 215 : event->record_critical_state (caller_var, state);
2372 : }
2373 : }
2374 1193 : break;
2375 :
2376 601 : case event_kind::return_:
2377 601 : {
2378 601 : if (sval)
2379 : {
2380 431 : return_event *event = (return_event *)base_event;
2381 431 : const region_model *caller_model
2382 431 : = event->m_eedge.m_dest->get_state ().m_region_model;
2383 431 : tree caller_var = caller_model->get_representative_tree (sval);
2384 431 : const region_model *callee_model
2385 431 : = event->m_eedge.m_src->get_state ().m_region_model;
2386 431 : callsite_expr expr;
2387 :
2388 431 : tree callee_var;
2389 :
2390 431 : if (auto op = event->get_call_and_return_op ())
2391 : {
2392 431 : tree callee_fndecl
2393 431 : = event->m_eedge.m_src->get_point ().get_fndecl ();
2394 431 : callee_var
2395 431 : = op->map_expr_from_caller_to_callee (callee_fndecl,
2396 : caller_var,
2397 : &expr);
2398 : }
2399 : else
2400 0 : callee_var = callee_model->get_representative_tree (sval);
2401 :
2402 431 : if (callee_var)
2403 : {
2404 185 : if (get_logger ())
2405 : {
2406 0 : label_text sval_desc = sval->get_desc ();
2407 0 : log ("event %i:"
2408 : " recording critical state for %qs at return"
2409 : " from %qE in caller to %qE in callee",
2410 : idx, sval_desc.get (), callee_var, callee_var);
2411 0 : }
2412 185 : if (expr.return_value_p ())
2413 94 : event->record_critical_state (callee_var, state);
2414 : }
2415 : }
2416 : }
2417 : break;
2418 :
2419 : case event_kind::inlined_call:
2420 : /* We don't expect to see these yet, as they're added later.
2421 : We'd want to keep them around. */
2422 : break;
2423 :
2424 : case event_kind::setjmp_:
2425 : /* TODO: only show setjmp_events that matter i.e. those for which
2426 : there is a later rewind event using them. */
2427 : case event_kind::rewind_from_longjmp:
2428 : case event_kind::rewind_to_setjmp:
2429 : break;
2430 :
2431 : case event_kind::warning:
2432 : /* Always show the final "warning" event in the path. */
2433 : break;
2434 : }
2435 31697 : idx--;
2436 : }
2437 3991 : }
2438 :
2439 : /* Subroutine of diagnostic_manager::prune_for_sm_diagnostic.
2440 : If *EXPR is not suitable to be the expression of interest in
2441 : an sm-diagnostic, set *EXPR to NULL and log. */
2442 :
2443 : void
2444 0 : diagnostic_manager::update_for_unsuitable_sm_exprs (tree *expr) const
2445 : {
2446 0 : gcc_assert (expr);
2447 0 : if (*expr && !can_be_expr_of_interest_p (*expr))
2448 : {
2449 0 : log ("new var %qE is unsuitable; setting var to NULL", *expr);
2450 0 : *expr = NULL_TREE;
2451 : }
2452 0 : }
2453 :
2454 : /* Second pass of diagnostic_manager::prune_path: remove redundant
2455 : interprocedural information.
2456 :
2457 : For example, given:
2458 : (1)- calling "f2" from "f1"
2459 : (2)--- entry to "f2"
2460 : (3)--- calling "f3" from "f2"
2461 : (4)----- entry to "f3"
2462 : (5)--- returning to "f2" to "f3"
2463 : (6)- returning to "f1" to "f2"
2464 : with no other intervening events, then none of these events are
2465 : likely to be interesting to the user.
2466 :
2467 : Prune [..., call, function-entry, return, ...] triples repeatedly
2468 : until nothing has changed. For the example above, this would
2469 : remove events (3, 4, 5), and then remove events (1, 2, 6). */
2470 :
2471 : void
2472 3991 : diagnostic_manager::prune_interproc_events (checker_path *path) const
2473 : {
2474 3991 : bool changed = false;
2475 4208 : do
2476 : {
2477 4208 : changed = false;
2478 4208 : int idx = (signed)path->num_events () - 1;
2479 21812 : while (idx >= 0)
2480 : {
2481 : /* Prune [..., call, function-entry, return, ...] triples. */
2482 17604 : if (idx + 2 < (signed)path->num_events ()
2483 9572 : && path->get_checker_event (idx)->is_call_p ()
2484 932 : && path->get_checker_event (idx + 1)->is_function_entry_p ()
2485 18528 : && path->get_checker_event (idx + 2)->is_return_p ())
2486 : {
2487 304 : if (get_logger ())
2488 : {
2489 0 : label_text desc
2490 0 : (path->get_checker_event (idx)->get_desc
2491 0 : (*global_dc->get_reference_printer ()));
2492 0 : log ("filtering events %i-%i:"
2493 : " irrelevant call/entry/return: %s",
2494 : idx, idx + 2, desc.get ());
2495 0 : }
2496 304 : path->delete_event (idx + 2);
2497 304 : path->delete_event (idx + 1);
2498 304 : path->delete_event (idx);
2499 304 : changed = true;
2500 304 : idx--;
2501 304 : continue;
2502 304 : }
2503 :
2504 : /* Prune [..., call, return, ...] pairs
2505 : (for -fanalyzer-verbosity=0). */
2506 17300 : if (idx + 1 < (signed)path->num_events ()
2507 13046 : && path->get_checker_event (idx)->is_call_p ()
2508 18287 : && path->get_checker_event (idx + 1)->is_return_p ())
2509 : {
2510 4 : if (get_logger ())
2511 : {
2512 0 : label_text desc
2513 0 : (path->get_checker_event (idx)->get_desc
2514 0 : (*global_dc->get_reference_printer ()));
2515 0 : log ("filtering events %i-%i:"
2516 : " irrelevant call/return: %s",
2517 : idx, idx + 1, desc.get ());
2518 0 : }
2519 4 : path->delete_event (idx + 1);
2520 4 : path->delete_event (idx);
2521 4 : changed = true;
2522 4 : idx--;
2523 4 : continue;
2524 4 : }
2525 :
2526 17296 : idx--;
2527 : }
2528 :
2529 : }
2530 : while (changed);
2531 3991 : }
2532 :
2533 : /* Remove everything within [call point, IDX]. For consistency,
2534 : IDX should represent the return event of the frame to delete,
2535 : or if there is none it should be the last event of the frame.
2536 : After this function, IDX designates the event prior to calling
2537 : this frame. */
2538 :
2539 : static void
2540 0 : prune_frame (checker_path *path, int &idx)
2541 : {
2542 0 : gcc_assert (idx >= 0);
2543 0 : int nesting = 1;
2544 0 : if (path->get_checker_event (idx)->is_return_p ())
2545 0 : nesting = 0;
2546 0 : do
2547 : {
2548 0 : if (path->get_checker_event (idx)->is_call_p ())
2549 0 : nesting--;
2550 0 : else if (path->get_checker_event (idx)->is_return_p ())
2551 0 : nesting++;
2552 :
2553 0 : path->delete_event (idx--);
2554 0 : } while (idx >= 0 && nesting != 0);
2555 0 : }
2556 :
2557 : /* This function is called when fanalyzer-show-events-in-system-headers
2558 : is disabled and will prune the diagnostic of all events within a
2559 : system header, only keeping the entry and exit events to the header.
2560 : This should be called after diagnostic_manager::prune_interproc_events
2561 : so that sucessive events [system header call, system header return]
2562 : are preserved thereafter.
2563 :
2564 : Given a diagnostics path diving into a system header in the form
2565 : [
2566 : prefix events...,
2567 : system header call,
2568 : system header entry,
2569 : events within system headers...,
2570 : system header return,
2571 : suffix events...
2572 : ]
2573 :
2574 : then transforms it into
2575 : [
2576 : prefix events...,
2577 : system header call,
2578 : system header return,
2579 : suffix events...
2580 : ]. */
2581 :
2582 : void
2583 3989 : diagnostic_manager::prune_system_headers (checker_path *path) const
2584 : {
2585 3989 : int idx = (signed)path->num_events () - 1;
2586 19409 : while (idx >= 0)
2587 : {
2588 15420 : const checker_event *event = path->get_checker_event (idx);
2589 : /* Prune everything between
2590 : [..., system entry, (...), system return, ...]. */
2591 15420 : if (event->is_return_p ()
2592 15420 : && in_system_header_at (event->get_location ()))
2593 : {
2594 0 : int ret_idx = idx;
2595 0 : prune_frame (path, idx);
2596 :
2597 0 : if (get_logger ())
2598 : {
2599 0 : log ("filtering system headers events %i-%i:",
2600 : idx, ret_idx);
2601 : }
2602 : // Delete function entry within system headers.
2603 0 : if (idx >= 0)
2604 : {
2605 0 : event = path->get_checker_event (idx);
2606 0 : if (event->is_function_entry_p ()
2607 0 : && in_system_header_at (event->get_location ()))
2608 : {
2609 0 : if (get_logger ())
2610 : {
2611 0 : label_text desc
2612 0 : (event->get_desc (*global_dc->get_reference_printer ()));
2613 0 : log ("filtering event %i:"
2614 : "system header entry event: %s",
2615 : idx, desc.get ());
2616 0 : }
2617 :
2618 0 : path->delete_event (idx);
2619 : }
2620 : }
2621 : }
2622 :
2623 15420 : idx--;
2624 : }
2625 3989 : }
2626 :
2627 : /* Return true iff event IDX within PATH is on the same line as REF_EXP_LOC. */
2628 :
2629 : static bool
2630 2712 : same_line_as_p (const expanded_location &ref_exp_loc,
2631 : checker_path *path, unsigned idx)
2632 : {
2633 2712 : const checker_event *ev = path->get_checker_event (idx);
2634 2712 : expanded_location idx_exp_loc = expand_location (ev->get_location ());
2635 2712 : gcc_assert (ref_exp_loc.file);
2636 2712 : if (idx_exp_loc.file == nullptr)
2637 : return false;
2638 2689 : if (strcmp (ref_exp_loc.file, idx_exp_loc.file))
2639 : return false;
2640 2689 : return ref_exp_loc.line == idx_exp_loc.line;
2641 : }
2642 :
2643 : /* This path-readability optimization reduces the verbosity of compound
2644 : conditional statements (without needing to reconstruct the AST, which
2645 : has already been lost).
2646 :
2647 : For example, it converts:
2648 :
2649 : | 61 | if (cp[0] != '\0' && cp[0] != '#')
2650 : | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2651 : | | | | |
2652 : | | | | (6) ...to here
2653 : | | | (7) following ‘true’ branch...
2654 : | | (5) following ‘true’ branch...
2655 : | 62 | {
2656 : | 63 | alias = cp++;
2657 : | | ~~~~
2658 : | | |
2659 : | | (8) ...to here
2660 :
2661 : into:
2662 :
2663 : | 61 | if (cp[0] != '\0' && cp[0] != '#')
2664 : | | ~
2665 : | | |
2666 : | | (5) following ‘true’ branch...
2667 : | 62 | {
2668 : | 63 | alias = cp++;
2669 : | | ~~~~
2670 : | | |
2671 : | | (6) ...to here
2672 :
2673 : by combining events 5-8 into new events 5-6.
2674 :
2675 : Find runs of consecutive (start_cfg_edge_event, end_cfg_edge_event) pairs
2676 : in which all events apart from the final end_cfg_edge_event are on the same
2677 : line, and for which either all the CFG edges are TRUE edges, or all are
2678 : FALSE edges.
2679 :
2680 : Consolidate each such run into a
2681 : (start_consolidated_cfg_edges_event, end_consolidated_cfg_edges_event)
2682 : pair. */
2683 :
2684 : void
2685 3991 : diagnostic_manager::consolidate_conditions (checker_path *path) const
2686 : {
2687 : /* Don't simplify edges if we're debugging them. */
2688 3991 : if (flag_analyzer_verbose_edges)
2689 : return;
2690 :
2691 11291 : for (int start_idx = 0;
2692 30473 : start_idx < (signed)path->num_events () - 1;
2693 : start_idx++)
2694 : {
2695 11291 : if (path->cfg_edge_pair_at_p (start_idx))
2696 : {
2697 2455 : const checker_event *old_start_ev
2698 2455 : = path->get_checker_event (start_idx);
2699 2455 : expanded_location start_exp_loc
2700 2455 : = expand_location (old_start_ev->get_location ());
2701 2455 : if (start_exp_loc.file == nullptr)
2702 2104 : continue;
2703 2455 : if (!same_line_as_p (start_exp_loc, path, start_idx + 1))
2704 2104 : continue;
2705 :
2706 : /* Are we looking for a run of all TRUE edges, or all FALSE edges? */
2707 351 : gcc_assert (old_start_ev->get_kind () == event_kind::start_cfg_edge);
2708 351 : const start_cfg_edge_event *old_start_cfg_ev
2709 : = (const start_cfg_edge_event *)old_start_ev;
2710 351 : bool edge_sense;
2711 351 : if (!old_start_cfg_ev->maybe_get_edge_sense (&edge_sense))
2712 0 : continue;
2713 :
2714 : /* Find a run of CFG start/end event pairs from
2715 : [start_idx, next_idx)
2716 : where all apart from the final event are on the same line,
2717 : and all are either TRUE or FALSE edges, matching the initial. */
2718 351 : int next_idx = start_idx + 2;
2719 351 : while (path->cfg_edge_pair_at_p (next_idx)
2720 467 : && same_line_as_p (start_exp_loc, path, next_idx))
2721 : {
2722 156 : const checker_event *iter_ev
2723 156 : = path->get_checker_event (next_idx);
2724 156 : gcc_assert (iter_ev->get_kind () == event_kind::start_cfg_edge);
2725 156 : const start_cfg_edge_event *iter_cfg_ev
2726 : = (const start_cfg_edge_event *)iter_ev;
2727 156 : bool iter_edge_sense;
2728 156 : if (!iter_cfg_ev->maybe_get_edge_sense (&iter_edge_sense))
2729 : break;
2730 156 : if (iter_edge_sense != edge_sense)
2731 : break;
2732 116 : next_idx += 2;
2733 : }
2734 :
2735 : /* If we have more than one pair in the run, consolidate. */
2736 351 : if (next_idx > start_idx + 2)
2737 : {
2738 108 : const checker_event *old_end_ev
2739 108 : = path->get_checker_event (next_idx - 1);
2740 108 : log ("consolidating CFG edge events %i-%i into %i-%i",
2741 : start_idx, next_idx - 1, start_idx, start_idx +1);
2742 108 : start_consolidated_cfg_edges_event *new_start_ev
2743 : = new start_consolidated_cfg_edges_event
2744 108 : (event_loc_info (old_start_ev->get_location (),
2745 : old_start_ev->get_fndecl (),
2746 108 : old_start_ev->get_stack_depth ()),
2747 108 : edge_sense);
2748 108 : checker_event *new_end_ev
2749 : = new end_consolidated_cfg_edges_event
2750 108 : (event_loc_info (old_end_ev->get_location (),
2751 : old_end_ev->get_fndecl (),
2752 108 : old_end_ev->get_stack_depth ()));
2753 108 : path->replace_event (start_idx, new_start_ev);
2754 108 : path->replace_event (start_idx + 1, new_end_ev);
2755 108 : path->delete_events (start_idx + 2, next_idx - (start_idx + 2));
2756 : }
2757 : }
2758 : }
2759 : }
2760 :
2761 : /* Consolidate runs of consecutive unwind_event. */
2762 :
2763 : void
2764 3991 : diagnostic_manager::consolidate_unwind_events (checker_path *path) const
2765 : {
2766 : /* Don't simplify edges if we're debugging them. */
2767 3991 : if (flag_analyzer_verbose_edges)
2768 : return;
2769 :
2770 11285 : for (int start_idx = 0;
2771 30461 : start_idx < (signed)path->num_events () - 1;
2772 : start_idx++)
2773 : {
2774 : /* Find a run of consecutive unwind_event instances. */
2775 11285 : if (path->get_checker_event (start_idx)->get_kind ()
2776 : != event_kind::unwind)
2777 11276 : continue;
2778 9 : int iter_idx = start_idx + 1;
2779 15 : while (iter_idx < (int)path->num_events ())
2780 15 : if (path->get_checker_event (iter_idx)->get_kind ()
2781 : == event_kind::unwind)
2782 6 : ++iter_idx;
2783 : else
2784 : break;
2785 :
2786 : /* iter_idx should now be one after the last unwind_event in the run. */
2787 9 : const int last_idx = iter_idx - 1;
2788 9 : if (last_idx == start_idx)
2789 3 : continue;
2790 :
2791 6 : gcc_assert (last_idx > start_idx);
2792 :
2793 6 : log ("consolidating unwind events %i-%i into %i",
2794 : start_idx, last_idx, start_idx);
2795 :
2796 6 : unwind_event *first_event
2797 6 : = (unwind_event *)path->get_checker_event (start_idx);
2798 6 : const unwind_event *last_event
2799 6 : = (const unwind_event *)path->get_checker_event (last_idx);
2800 6 : first_event->m_num_frames += last_event->m_num_frames;
2801 6 : path->delete_events (start_idx + 1, last_idx - start_idx);
2802 : }
2803 : }
2804 :
2805 : /* Final pass of diagnostic_manager::prune_path.
2806 :
2807 : If all we're left with is in one function, then filter function entry
2808 : events. */
2809 :
2810 : void
2811 3991 : diagnostic_manager::finish_pruning (checker_path *path) const
2812 : {
2813 3991 : if (!path->interprocedural_p ())
2814 : {
2815 3214 : int idx = path->num_events () - 1;
2816 23426 : while (idx >= 0 && idx < (signed)path->num_events ())
2817 : {
2818 10106 : checker_event *base_event = path->get_checker_event (idx);
2819 10106 : if (base_event->get_kind () == event_kind::function_entry)
2820 : {
2821 3118 : log ("filtering event %i:"
2822 : " function entry for purely intraprocedural path", idx);
2823 3118 : path->delete_event (idx);
2824 : }
2825 10106 : idx--;
2826 : }
2827 : }
2828 3991 : }
2829 :
2830 : } // namespace ana
2831 :
2832 : #endif /* #if ENABLE_ANALYZER */
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