Sema: Remove SolverScope::numFixes

Author: slavapestov

include/swift/Sema/ConstraintSystem.h

@@ -2533,8 +2533,8 @@ class ConstraintSystem {
     /// The number of the solution attempts we're looking at.
     unsigned SolutionAttempt;
 
-    /// Refers to the innermost partial solution scope.
-    SolverScope *PartialSolutionScope = nullptr;
+    /// The number of fixes in the innermost partial solution scope.
+    unsigned numPartialSolutionFixes = 0;
 
     // Statistics
     #define CS_STATISTIC(Name, Description) unsigned Name = 0;
@@ -2784,11 +2784,6 @@ class ConstraintSystem {
     /// The length of \c Trail.
     unsigned numTrailChanges;
 
-    /// The length of \c Fixes.
-    ///
-    /// FIXME: Remove this.
-    unsigned numFixes;
-
     /// The scope number of this scope. Set when the scope is registered.
     unsigned scopeNumber = 0;
 

lib/Sema/CSSolver.cpp

@@ -128,11 +128,8 @@ Solution ConstraintSystem::finalize() {
 
   // For each of the fixes, record it as an operation on the affected
   // expression.
-  unsigned firstFixIndex = 0;
-  if (solverState && solverState->PartialSolutionScope) {
-    firstFixIndex = solverState->PartialSolutionScope->numFixes;
-  }
-
+  unsigned firstFixIndex =
+      (solverState ? solverState->numPartialSolutionFixes : 0);
   for (const auto &fix :
        llvm::make_range(Fixes.begin() + firstFixIndex, Fixes.end()))
     solution.Fixes.push_back(fix);
@@ -709,7 +706,6 @@ ConstraintSystem::SolverScope::SolverScope(ConstraintSystem &cs)
   numTrailChanges = cs.solverState->Trail.size();
 
   numTypeVariables = cs.TypeVariables.size();
-  numFixes = cs.Fixes.size();
 
   cs.solverState->beginScope(this);
   assert(!cs.failedConstraint && "Unexpected failed constraint!");

lib/Sema/CSStep.cpp

@@ -42,8 +42,8 @@ ComponentStep::Scope::Scope(ComponentStep &component)
   workList.splice(workList.end(), *component.Constraints);
 
   SolverScope = new ConstraintSystem::SolverScope(CS);
-  PrevPartialScope = CS.solverState->PartialSolutionScope;
-  CS.solverState->PartialSolutionScope = SolverScope;
+  prevPartialSolutionFixes = CS.solverState->numPartialSolutionFixes;
+  CS.solverState->numPartialSolutionFixes = CS.Fixes.size();
 }
 
 StepResult SplitterStep::take(bool prevFailed) {

lib/Sema/CSStep.h

@@ -342,7 +342,7 @@ class ComponentStep final : public SolverStep {
     ConstraintSystem::SolverScope *SolverScope;
 
     SetVector<TypeVariableType *> TypeVars;
-    ConstraintSystem::SolverScope *PrevPartialScope = nullptr;
+    unsigned prevPartialSolutionFixes = 0;
 
     // The component this scope is associated with.
     ComponentStep &Component;
@@ -352,7 +352,7 @@ class ComponentStep final : public SolverStep {
 
     ~Scope() {
       delete SolverScope; // rewind back all of the changes.
-      CS.solverState->PartialSolutionScope = PrevPartialScope;
+      CS.solverState->numPartialSolutionFixes = prevPartialSolutionFixes;
 
       // return all of the saved type variables back to the system.
       CS.TypeVariables = std::move(TypeVars);