More useful output on path strategy unit tests

The path strategy unit tests now emit an index showing which result in
the expected list of results was the one that failed.

Author: karkhaz

unit/path_strategies.cpp

@@ -269,12 +269,14 @@ SCENARIO("path strategies")
 
 void symex_eventt::validate_result(
   listt &events,
-  const safety_checkert::resultt result)
+  const safety_checkert::resultt result,
+  std::size_t &counter)
 {
   INFO(
     "Expecting result to be '"
     << (result == safety_checkert::resultt::SAFE ? "success" : "failure")
-    << "'");
+    << "' (item at index [" << counter << "] in expected results list");
+  ++counter;
 
   REQUIRE(result != safety_checkert::resultt::ERROR);
 
@@ -294,25 +296,33 @@ void symex_eventt::validate_result(
 
 void symex_eventt::validate_resume(
   listt &events,
-  const goto_symex_statet &state)
+  const goto_symex_statet &state,
+  std::size_t &counter)
 {
   REQUIRE(!events.empty());
 
   int dst = std::stoi(state.saved_target->source_location.get_line().c_str());
 
   if(state.has_saved_jump_target)
   {
-    INFO("Expecting resume to be 'jump' to line " << dst);
+    INFO(
+      "Expecting resume to be 'jump' to line "
+      << dst << " (item at index [" << counter
+      << "] in expected resumes list)");
     REQUIRE(events.front().first == symex_eventt::enumt::JUMP);
   }
   else if(state.has_saved_next_instruction)
   {
-    INFO("Expecting resume to be 'next' to line " << dst);
+    INFO(
+      "Expecting resume to be 'next' to line "
+      << dst << " (item at index [" << counter
+      << "] in expected resumes list)");
     REQUIRE(events.front().first == symex_eventt::enumt::NEXT);
   }
   else
     REQUIRE(false);
 
+  ++counter;
   REQUIRE(events.front().second == dst);
 
   events.pop_front();
@@ -369,7 +379,9 @@ void _check_with_strategy(
 
   bmct bmc(opts, gm.get_symbol_table(), mh, pc, *worklist, callback);
   safety_checkert::resultt result = bmc.run(gm);
-  symex_eventt::validate_result(events, result);
+
+  std::size_t expected_results_cnt = 0;
+  symex_eventt::validate_result(events, result, expected_results_cnt);
 
   if(
     result == safety_checkert::resultt::UNSAFE &&
@@ -385,7 +397,7 @@ void _check_with_strategy(
     prop_convt &pc = cbmc_solver->prop_conv();
     path_storaget::patht &resume = worklist->peek();
 
-    symex_eventt::validate_resume(events, resume.state);
+    symex_eventt::validate_resume(events, resume.state, expected_results_cnt);
 
     path_explorert pe(
       opts,
@@ -398,7 +410,7 @@ void _check_with_strategy(
       callback);
     result = pe.run(gm);
 
-    symex_eventt::validate_result(events, result);
+    symex_eventt::validate_result(events, result, expected_results_cnt);
     worklist->pop();
 
     if(

unit/path_strategies.h

@@ -36,10 +36,13 @@ struct symex_eventt
     return pairt(kind, -1);
   }
 
-  static void
-  validate_result(listt &events, const safety_checkert::resultt result);
+  static void validate_result(
+    listt &events,
+    const safety_checkert::resultt result,
+    std::size_t &);
 
-  static void validate_resume(listt &events, const goto_symex_statet &state);
+  static void
+  validate_resume(listt &events, const goto_symex_statet &state, std::size_t &);
 };
 
 void _check_with_strategy(