Sema: Remove Solution::PackElementGenericEnvironments

Author: slavapestov

include/swift/Sema/ConstraintSystem.h

@@ -1549,10 +1549,6 @@ class Solution {
   llvm::DenseMap<PackElementExpr *, PackExpansionExpr *>
       PackEnvironments;
 
-  /// The outer pack element generic environment to use when dealing with nested
-  /// pack iteration (see \c getPackElementEnvironment).
-  llvm::SmallVector<GenericEnvironment *> PackElementGenericEnvironments;
-
   /// The locators of \c Defaultable constraints whose defaults were used.
   llvm::DenseSet<ConstraintLocator *> DefaultedConstraints;
 
@@ -2883,9 +2879,6 @@ class ConstraintSystem {
     /// FIXME: Remove this.
     unsigned numFixes;
 
-    /// The length of \c PackElementGenericEnvironments.
-    unsigned numPackElementGenericEnvironments;
-
     /// The length of \c DefaultedConstraints.
     unsigned numDefaultedConstraints;
 

lib/Sema/CSGen.cpp

@@ -4945,6 +4945,7 @@ bool ConstraintSystem::generateConstraints(
     // Cache the outer generic environment, if it exists.
     if (target.getPackElementEnv()) {
       PackElementGenericEnvironments.push_back(target.getPackElementEnv());
+      ASSERT(!isRecordingChanges() && "Need to record a change");
     }
 
     // For a for-each statement, generate constraints for the pattern, where

lib/Sema/CSSolver.cpp

@@ -264,9 +264,6 @@ Solution ConstraintSystem::finalize() {
   for (const auto &packEnv : PackEnvironments)
     solution.PackEnvironments.insert(packEnv);
 
-  for (const auto &packEltGenericEnv : PackElementGenericEnvironments)
-    solution.PackElementGenericEnvironments.push_back(packEltGenericEnv);
-
   for (const auto &synthesized : SynthesizedConformances) {
     solution.SynthesizedConformances.insert(synthesized);
   }
@@ -349,12 +346,6 @@ void ConstraintSystem::applySolution(const Solution &solution) {
     addPackEnvironment(packEnvironment.first, packEnvironment.second);
   }
 
-  // Register the solutions's pack element generic environments.
-  for (auto &packElementGenericEnvironment :
-       solution.PackElementGenericEnvironments) {
-    PackElementGenericEnvironments.push_back(packElementGenericEnvironment);
-  }
-
   // Register the defaulted type variables.
   DefaultedConstraints.insert(solution.DefaultedConstraints.begin(),
                               solution.DefaultedConstraints.end());
@@ -672,7 +663,6 @@ ConstraintSystem::SolverScope::SolverScope(ConstraintSystem &cs)
 
   numTypeVariables = cs.TypeVariables.size();
   numFixes = cs.Fixes.size();
-  numPackElementGenericEnvironments = cs.PackElementGenericEnvironments.size();
   numDefaultedConstraints = cs.DefaultedConstraints.size();
   numAddedNodeTypes = cs.addedNodeTypes.size();
   numAddedKeyPathComponentTypes = cs.addedKeyPathComponentTypes.size();
@@ -729,10 +719,6 @@ ConstraintSystem::SolverScope::~SolverScope() {
   // constraints introduced by the current scope.
   cs.solverState->rollback(this);
 
-  // Remove any pack element generic environments.
-  truncate(cs.PackElementGenericEnvironments,
-           numPackElementGenericEnvironments);
-
   // Remove any defaulted type variables.
   truncate(cs.DefaultedConstraints, numDefaultedConstraints);
 

lib/Sema/ConstraintSystem.cpp

@@ -4473,7 +4473,6 @@ size_t Solution::getTotalMemory() const {
          OpenedPackExpansionTypes.getMemorySize() +
          PackExpansionEnvironments.getMemorySize() +
          size_in_bytes(PackEnvironments) +
-         PackElementGenericEnvironments.size() +
          (DefaultedConstraints.size() * sizeof(void *)) +
          nodeTypes.getMemorySize() +
          keyPathComponentTypes.getMemorySize() +