gcc/analyzer/feasible-graph.cc

   1 /* A graph for exploring trees of feasible paths through the egraph.
   2    Copyright (C) 2021-2022 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 "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tree.h"
  25 #include "pretty-print.h"
  26 #include "gcc-rich-location.h"
  27 #include "gimple-pretty-print.h"
  28 #include "function.h"
  29 #include "diagnostic-core.h"
  30 #include "diagnostic-event-id.h"
  31 #include "diagnostic-path.h"
  32 #include "alloc-pool.h"
  33 #include "fibonacci_heap.h"
  34 #include "shortest-paths.h"
  35 #include "sbitmap.h"
  36 #include "bitmap.h"
  37 #include "tristate.h"
  38 #include "selftest.h"
  39 #include "ordered-hash-map.h"
  40 #include "json.h"
  41 #include "analyzer/analyzer.h"
  42 #include "analyzer/analyzer-logging.h"
  43 #include "analyzer/sm.h"
  44 #include "analyzer/pending-diagnostic.h"
  45 #include "analyzer/diagnostic-manager.h"
  46 #include "analyzer/call-string.h"
  47 #include "analyzer/program-point.h"
  48 #include "analyzer/store.h"
  49 #include "analyzer/region-model.h"
  50 #include "analyzer/constraint-manager.h"
  51 #include "cfg.h"
  52 #include "basic-block.h"
  53 #include "gimple.h"
  54 #include "gimple-iterator.h"
  55 #include "cgraph.h"
  56 #include "digraph.h"
  57 #include "analyzer/supergraph.h"
  58 #include "analyzer/program-state.h"
  59 #include "analyzer/exploded-graph.h"
  60 #include "analyzer/feasible-graph.h"
  61
  62 #if ENABLE_ANALYZER
  63
  64 namespace ana {
  65
  66 /* class base_feasible_node : public dnode<fg_traits>.  */
  67
  68 /* Print an id to PP for this node suitable for use in .dot dumps.  */
  69
  70 void
  71 base_feasible_node::dump_dot_id (pretty_printer *pp) const
  72 {
  73   pp_printf (pp, "fnode_%i", m_index);
  74 }
  75
  76 /* class feasible_node : public base_feasible_node.  */
  77
  78 /* Implementation of dump_dot vfunc for feasible_node.  */
  79
  80 void
  81 feasible_node::dump_dot (graphviz_out *gv,
  82                         const dump_args_t &) const
  83 {
  84   pretty_printer *pp = gv->get_pp ();
  85
  86   dump_dot_id (pp);
  87   pp_printf (pp, " [shape=none,margin=0,style=filled,fillcolor=%s,label=\"",
  88              m_inner_node->get_dot_fillcolor ());
  89   pp_write_text_to_stream (pp);
  90
  91   pp_printf (pp, "FN: %i (EN: %i); len=%i", m_index, m_inner_node->m_index,
  92              m_path_length);
  93   pp_newline (pp);
  94
  95   format f (true);
  96   m_inner_node->get_point ().print (pp, f);
  97   pp_newline (pp);
  98
  99   /* Show the model at this point along expansion of the feasible path,
 100      rather than the model within the enode.  */
 101   m_state.get_model ().dump_to_pp (pp, true, true);
 102   pp_newline (pp);
 103
 104   m_inner_node->dump_processed_stmts (pp);
 105   m_inner_node->dump_saved_diagnostics (pp);
 106
 107   pp_write_text_as_dot_label_to_stream (pp, /*for_record=*/true);
 108
 109   pp_string (pp, "\"];\n\n");
 110   pp_flush (pp);
 111 }
 112
 113 /* Implementation of dump_dot vfunc for infeasible_node.
 114    In particular, show the rejected constraint.  */
 115
 116 void
 117 infeasible_node::dump_dot (graphviz_out *gv,
 118                            const dump_args_t &) const
 119 {
 120   pretty_printer *pp = gv->get_pp ();
 121
 122   dump_dot_id (pp);
 123   pp_printf (pp, " [shape=none,margin=0,style=filled,fillcolor=%s,label=\"",
 124              m_inner_node->get_dot_fillcolor ());
 125   pp_write_text_to_stream (pp);
 126
 127   pp_printf (pp, "infeasible edge to EN: %i", m_inner_node->m_index);
 128   pp_newline (pp);
 129
 130   pp_string (pp, "rejected constraint:");
 131   pp_newline (pp);
 132   m_rc->dump_to_pp (pp);
 133
 134   pp_write_text_as_dot_label_to_stream (pp, /*for_record=*/true);
 135
 136   pp_string (pp, "\"];\n\n");
 137   pp_flush (pp);
 138 }
 139
 140 /* class base_feasible_edge : public dedge<fg_traits>.  */
 141
 142 /* Implementation of dump_dot vfunc for base_easible_edge.  */
 143
 144 void
 145 base_feasible_edge::dump_dot (graphviz_out *gv, const dump_args_t &) const
 146 {
 147   pretty_printer *pp = gv->get_pp ();
 148
 149   m_src->dump_dot_id (pp);
 150   pp_string (pp, " -> ");
 151   m_dest->dump_dot_id (pp);
 152
 153   m_inner_edge->dump_dot_label (pp);
 154 }
 155
 156 /* class feasible_graph : public digraph <fg_traits>.  */
 157
 158 /* Ctor for feasible_graph.  */
 159
 160 feasible_graph::feasible_graph ()
 161 : m_num_infeasible (0)
 162 {
 163 }
 164
 165 /* Add a feasible_node to this graph for ENODE, STATE with the
 166    given PATH_LENGTH. */
 167
 168 feasible_node *
 169 feasible_graph::add_node (const exploded_node *enode,
 170                           const feasibility_state &state,
 171                           unsigned path_length)
 172 {
 173   /* We don't attempt get_or_create here.  */
 174   feasible_node *fnode = new feasible_node (enode, m_nodes.length (),
 175                                             state, path_length);
 176   digraph<fg_traits>::add_node (fnode);
 177   return fnode;
 178 }
 179
 180 /* Add an infeasible_node to this graph and an infeasible_edge connecting
 181    to it from SRC_FNODE, capturing a failure of RC along EEDGE.
 182    Takes ownership of RC.  */
 183
 184 void
 185 feasible_graph::add_feasibility_problem (feasible_node *src_fnode,
 186                                          const exploded_edge *eedge,
 187                                          rejected_constraint *rc)
 188 {
 189   infeasible_node *dst_fnode
 190     = new infeasible_node (eedge->m_dest, m_nodes.length (), rc);
 191   digraph<fg_traits>::add_node (dst_fnode);
 192   add_edge (new infeasible_edge (src_fnode, dst_fnode, eedge));
 193   m_num_infeasible++;
 194 }
 195
 196 /* Make an exploded_path from the origin to FNODE's exploded_node,
 197    following the edges in the feasible_graph.  */
 198
 199 exploded_path *
 200 feasible_graph::make_epath (feasible_node *fnode) const
 201 {
 202   exploded_path *epath = new exploded_path ();
 203
 204   /* FG is actually a tree.  Built the path backwards, by walking
 205      backwards from FNODE until we reach the origin.  */
 206   while (fnode->get_inner_node ()->m_index != 0)
 207     {
 208       gcc_assert (fnode->m_preds.length () == 1);
 209       feasible_edge *pred_fedge
 210         = static_cast <feasible_edge *> (fnode->m_preds[0]);
 211       epath->m_edges.safe_push (pred_fedge->get_inner_edge ());
 212       fnode = static_cast <feasible_node *> (pred_fedge->m_src);
 213     }
 214
 215   /* Now reverse it.  */
 216   epath->m_edges.reverse ();
 217
 218   return epath;
 219 }
 220
 221 /* Dump the path to DST_FNODE in textual form to PP.  */
 222
 223 void
 224 feasible_graph::dump_feasible_path (const feasible_node &dst_fnode,
 225                                     pretty_printer *pp) const
 226 {
 227   const feasible_node *fnode = &dst_fnode;
 228
 229   auto_vec<const feasible_edge *> fpath;
 230
 231   /* FG is actually a tree.  Built the path backwards, by walking
 232      backwards from FNODE until we reach the origin.  */
 233   while (fnode->get_inner_node ()->m_index != 0)
 234     {
 235       gcc_assert (fnode->m_preds.length () == 1);
 236       feasible_edge *pred_fedge
 237         = static_cast <feasible_edge *> (fnode->m_preds[0]);
 238       fpath.safe_push (pred_fedge);
 239       fnode = static_cast <const feasible_node *> (pred_fedge->m_src);
 240     }
 241
 242   /* Now reverse it.  */
 243   fpath.reverse ();
 244
 245   for (unsigned i = 0; i < fpath.length (); i++)
 246     {
 247       const feasible_edge *fedge = fpath[i];
 248       const feasible_node *src_fnode
 249         = static_cast <const feasible_node *> (fedge->m_src);
 250       const feasible_node *dest_fnode
 251         = static_cast <const feasible_node *> (fedge->m_dest);
 252
 253       pp_printf (pp, "fpath[%i]: FN %i (EN %i) -> FN %i (EN %i)",
 254                  i,
 255                  src_fnode->get_index (),
 256                  src_fnode->get_inner_node ()->m_index,
 257                  dest_fnode->get_index (),
 258                  dest_fnode->get_inner_node ()->m_index);
 259       pp_newline (pp);
 260       pp_printf (pp, "  FN %i (EN %i):",
 261                  dest_fnode->get_index (),
 262                  dest_fnode->get_inner_node ()->m_index);
 263       pp_newline (pp);
 264       const program_point &point = dest_fnode->get_inner_node ()->get_point ();
 265       point.print (pp, format (true));
 266       dest_fnode->get_state ().dump_to_pp (pp, true, true);
 267       pp_newline (pp);
 268     }
 269 }
 270
 271 /* Dump the path to DST_FNODE in textual form to FILENAME.  */
 272
 273 void
 274 feasible_graph::dump_feasible_path (const feasible_node &dst_fnode,
 275                                     const char *filename) const
 276 {
 277   FILE *fp = fopen (filename, "w");
 278   pretty_printer pp;
 279   pp_format_decoder (&pp) = default_tree_printer;
 280   pp.buffer->stream = fp;
 281   dump_feasible_path (dst_fnode, &pp);
 282   pp_flush (&pp);
 283   fclose (fp);
 284 }
 285
 286 /* Dump stats about this graph to LOGGER.  */
 287
 288 void
 289 feasible_graph::log_stats (logger *logger) const
 290 {
 291   logger->log ("#nodes: %i", m_nodes.length ());
 292   logger->log ("#edges: %i", m_edges.length ());
 293   logger->log ("#feasible nodes: %i", m_nodes.length () - m_num_infeasible);
 294   logger->log ("#feasible edges: %i", m_edges.length () - m_num_infeasible);
 295   logger->log ("#infeasible nodes/edges: %i", m_num_infeasible);
 296 }
 297
 298 } // namespace ana
 299
 300 #endif /* #if ENABLE_ANALYZER */