[TypeChecker] Add getter/setter methods for retiredConstraints of SolverState

Author: xedin

lib/Sema/CSSolver.cpp

@@ -359,7 +359,7 @@ bool ConstraintSystem::simplify(bool ContinueAfterFailures) {
       }
 
       if (solverState)
-        solverState->retiredConstraints.push_front(constraint);
+        solverState->retireConstraint(constraint);
 
       CG.removeConstraint(constraint);
       break;
@@ -369,7 +369,7 @@ bool ConstraintSystem::simplify(bool ContinueAfterFailures) {
         ++solverState->NumSimplifiedConstraints;
 
         // This constraint has already been solved; retire it.
-        solverState->retiredConstraints.push_front(constraint);
+        solverState->retireConstraint(constraint);
       }
 
       // Remove the constraint from the constraint graph.
@@ -2396,11 +2396,11 @@ bool ConstraintSystem::solveSimplified(
     case SolutionKind::Error:
       if (!failedConstraint)
         failedConstraint = constraint;
-      solverState->retiredConstraints.push_front(constraint);
+      solverState->retireConstraint(constraint);
       break;
 
     case SolutionKind::Solved:
-      solverState->retiredConstraints.push_front(constraint);
+      solverState->retireConstraint(constraint);
       break;
 
     case SolutionKind::Unsolved:

lib/Sema/ConstraintSystem.h

@@ -1016,11 +1016,6 @@ class ConstraintSystem {
     /// \brief Whether to record failures or not.
     bool recordFixes = false;
 
-    /// The list of constraints that have been retired along the
-    /// current path, this list is used in LIFO fasion when constaints
-    /// are added back to the circulation.
-    ConstraintList retiredConstraints;
-
     /// The current set of generated constraints.
     SmallVector<Constraint *, 4> generatedConstraints;
 
@@ -1051,6 +1046,28 @@ class ConstraintSystem {
                                             generatedConstraints.size()) });
     }
 
+    /// \brief Check whether there are any retired constraints present.
+    bool hasRetiredConstraints() const {
+      return !retiredConstraints.empty();
+    }
+
+    /// \brief Mark given constraint as retired along current solver path.
+    ///
+    /// \param constraint The constraint to retire temporarily.
+    void retireConstraint(Constraint *constraint) {
+      retiredConstraints.push_front(constraint);
+    }
+
+    /// \brief Iterate over all of the retired constraints registered with
+    /// current solver state.
+    ///
+    /// \param processor The processor function to be applied to each of
+    /// the constraints retrieved.
+    void forEachRetired(std::function<void(Constraint &)> processor) {
+      for (auto &constraint : retiredConstraints)
+        processor(constraint);
+    }
+
     /// \brief Restore all of the retired/generated constraints to the state
     /// before given scope. This is required because retired constraints have
     /// to be re-introduced to the system in order of arrival (LIFO) and list
@@ -1088,6 +1105,11 @@ class ConstraintSystem {
     }
 
   private:
+    /// The list of constraints that have been retired along the
+    /// current path, this list is used in LIFO fasion when constaints
+    /// are added back to the circulation.
+    ConstraintList retiredConstraints;
+
     /// The collection which holds association between solver scope
     /// and position of the last retired constraint and number of
     /// constraints generated before registration of given scope,
@@ -1564,7 +1586,7 @@ class ConstraintSystem {
     // Record this as a newly-generated constraint.
     if (solverState) {
       solverState->generatedConstraints.push_back(constraint);
-      solverState->retiredConstraints.push_front(constraint);
+      solverState->retireConstraint(constraint);
     }
   }
 
@@ -1588,7 +1610,7 @@ class ConstraintSystem {
     InactiveConstraints.erase(constraint);
 
     if (solverState)
-      solverState->retiredConstraints.push_front(constraint);
+      solverState->retireConstraint(constraint);
   }
 
   /// Retrieve the list of inactive constraints.

lib/Sema/TypeCheckConstraints.cpp

@@ -2696,13 +2696,13 @@ void ConstraintSystem::print(raw_ostream &out) {
     out << "\n";
   }
 
-  if (solverState && !solverState->retiredConstraints.empty()) {
+  if (solverState && !solverState->hasRetiredConstraints()) {
     out << "\nRetired Constraints:\n";
-    for (auto &constraint : solverState->retiredConstraints) {
+    solverState->forEachRetired([&](Constraint &constraint) {
       out.indent(2);
       constraint.print(out, &getTypeChecker().Context.SourceMgr);
       out << "\n";
-    }
+    });
   }
 
   if (resolvedOverloadSets) {