[clang][dataflow] Rename member to make it clear that it isn't stable

[sgatev]

Summary

Rename DataflowAnalysisContext::getStableStorageLocation(QualType) to createStorageLocation, to make it clear that it doesn't return a stable storage location.

[sgatev]

Update commit message

[ymandel]

Thanks!

clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h

public:
   template <typename T>
   typename std::enable_if<std::is_base_of<Value, T>::value, T &>::type
   takeOwnership(std::unique_ptr<T> Val) {
     assert(Val != nullptr);
     Vals.push_back(std::move(Val));
     return *cast<T>(Vals.back().get());
   }
 
-  /// Returns a stable storage location appropriate for `Type`.
+  /// Returns a new storage location appropriate for `Type`.
   ///
   /// Requirements:
   ///
   ///  `Type` must not be null.
-  StorageLocation &getStableStorageLocation(QualType Type);
+  StorageLocation &createStorageLocation(QualType Type);
 
   /// Returns a stable storage location for `D`.
   StorageLocation &getStableStorageLocation(const VarDecl &D);
 
   /// Returns a stable storage location for `E`.
   StorageLocation &getStableStorageLocation(const Expr &E);
 
   /// Assigns `Loc` as the storage location of `D`.

clang/lib/Analysis/FlowSensitive/DataflowAnalysisContext.cpp

 #include "llvm/Support/Debug.h"
 #include <cassert>
 #include <memory>
 #include <utility>
 
 namespace clang {
 namespace dataflow {
 
-StorageLocation &
-DataflowAnalysisContext::getStableStorageLocation(QualType Type) {
+StorageLocation &DataflowAnalysisContext::createStorageLocation(QualType Type) {
   if (!Type.isNull() &&
       (Type->isStructureOrClassType() || Type->isUnionType())) {
     // FIXME: Explore options to avoid eager initialization of fields as some of
     // them might not be needed for a particular analysis.
     llvm::DenseMap<const ValueDecl *, StorageLocation *> FieldLocs;
     for (const FieldDecl *Field : getObjectFields(Type))
-      FieldLocs.insert({Field, &getStableStorageLocation(Field->getType())});
+      FieldLocs.insert({Field, &createStorageLocation(Field->getType())});
     return takeOwnership(
         std::make_unique<AggregateStorageLocation>(Type, std::move(FieldLocs)));
   }
   return takeOwnership(std::make_unique<ScalarStorageLocation>(Type));
 }
 
 StorageLocation &
 DataflowAnalysisContext::getStableStorageLocation(const VarDecl &D) {
   if (auto *Loc = getStorageLocation(D))
     return *Loc;
-  auto &Loc = getStableStorageLocation(D.getType());
+  auto &Loc = createStorageLocation(D.getType());
   setStorageLocation(D, Loc);
   return Loc;
 }
 
 StorageLocation &
 DataflowAnalysisContext::getStableStorageLocation(const Expr &E) {
   if (auto *Loc = getStorageLocation(E))
     return *Loc;
-  auto &Loc = getStableStorageLocation(E.getType());
+  auto &Loc = createStorageLocation(E.getType());
   setStorageLocation(E, Loc);
   return Loc;
 }
 
 PointerValue &
 DataflowAnalysisContext::getOrCreateNullPointerValue(QualType PointeeType) {
   auto CanonicalPointeeType =
       PointeeType.isNull() ? PointeeType : PointeeType.getCanonicalType();
   auto Res = NullPointerVals.try_emplace(CanonicalPointeeType, nullptr);
   if (Res.second) {
-    auto &PointeeLoc = getStableStorageLocation(CanonicalPointeeType);
+    auto &PointeeLoc = createStorageLocation(CanonicalPointeeType);
     Res.first->second =
         &takeOwnership(std::make_unique<PointerValue>(PointeeLoc));
   }
   return *Res.first->second;
 }
 
 static std::pair<BoolValue *, BoolValue *>
 makeCanonicalBoolValuePair(BoolValue &LHS, BoolValue &RHS) {

clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp

if (LocToVal.size() != JoinedEnv.LocToVal.size())
     Effect = LatticeJoinEffect::Changed;
 
   *this = std::move(JoinedEnv);
 
   return Effect;
 }
 
 StorageLocation &Environment::createStorageLocation(QualType Type) {
-  return DACtx->getStableStorageLocation(Type);
+  return DACtx->createStorageLocation(Type);
 }
 
 StorageLocation &Environment::createStorageLocation(const VarDecl &D) {
   // Evaluated declarations are always assigned the same storage locations to
   // ensure that the environment stabilizes across loop iterations. Storage
   // locations for evaluated declarations are stored in the analysis context.
   return DACtx->getStableStorageLocation(D);
 }