[clang] In Sema use new parentEvaluationContext function (#93338)

Fixes #93284

Author: a-tarasyuk

clang/include/clang/Sema/Sema.h

@@ -5153,12 +5153,16 @@ class Sema final : public SemaBase {
     return ExprEvalContexts.back();
   };
 
-  const ExpressionEvaluationContextRecord &parentEvaluationContext() const {
+  ExpressionEvaluationContextRecord &parentEvaluationContext() {
     assert(ExprEvalContexts.size() >= 2 &&
            "Must be in an expression evaluation context");
     return ExprEvalContexts[ExprEvalContexts.size() - 2];
   };
 
+  const ExpressionEvaluationContextRecord &parentEvaluationContext() const {
+    return const_cast<Sema *>(this)->parentEvaluationContext();
+  };
+
   bool isBoundsAttrContext() const {
     return ExprEvalContexts.back().ExprContext ==
            ExpressionEvaluationContextRecord::ExpressionKind::
@@ -6289,10 +6293,9 @@ class Sema final : public SemaBase {
   /// flag from previous context.
   void keepInLifetimeExtendingContext() {
     if (ExprEvalContexts.size() > 2 &&
-        ExprEvalContexts[ExprEvalContexts.size() - 2]
-            .InLifetimeExtendingContext) {
+        parentEvaluationContext().InLifetimeExtendingContext) {
       auto &LastRecord = ExprEvalContexts.back();
-      auto &PrevRecord = ExprEvalContexts[ExprEvalContexts.size() - 2];
+      auto &PrevRecord = parentEvaluationContext();
       LastRecord.InLifetimeExtendingContext =
           PrevRecord.InLifetimeExtendingContext;
     }

clang/lib/Sema/SemaExpr.cpp

@@ -17232,8 +17232,7 @@ ExprResult Sema::TransformToPotentiallyEvaluated(Expr *E) {
 TypeSourceInfo *Sema::TransformToPotentiallyEvaluated(TypeSourceInfo *TInfo) {
   assert(isUnevaluatedContext() &&
          "Should only transform unevaluated expressions");
-  ExprEvalContexts.back().Context =
-      ExprEvalContexts[ExprEvalContexts.size() - 2].Context;
+  ExprEvalContexts.back().Context = parentEvaluationContext().Context;
   if (isUnevaluatedContext())
     return TInfo;
   return TransformToPE(*this).TransformType(TInfo);
@@ -17250,14 +17249,13 @@ Sema::PushExpressionEvaluationContext(
   // discarded statements or immediate context are themselves
   // a discarded statement or an immediate context, respectively.
   ExprEvalContexts.back().InDiscardedStatement =
-      ExprEvalContexts[ExprEvalContexts.size() - 2]
-          .isDiscardedStatementContext();
+      parentEvaluationContext().isDiscardedStatementContext();
 
   // C++23 [expr.const]/p15
   // An expression or conversion is in an immediate function context if [...]
   // it is a subexpression of a manifestly constant-evaluated expression or
   // conversion.
-  const auto &Prev = ExprEvalContexts[ExprEvalContexts.size() - 2];
+  const auto &Prev = parentEvaluationContext();
   ExprEvalContexts.back().InImmediateFunctionContext =
       Prev.isImmediateFunctionContext() || Prev.isConstantEvaluated();
 
@@ -17702,7 +17700,7 @@ void Sema::PopExpressionEvaluationContext() {
 
   // Append the collected materialized temporaries into previous context before
   // exit if the previous also is a lifetime extending context.
-  auto &PrevRecord = ExprEvalContexts[ExprEvalContexts.size() - 2];
+  auto &PrevRecord = parentEvaluationContext();
   if (getLangOpts().CPlusPlus23 && Rec.InLifetimeExtendingContext &&
       PrevRecord.InLifetimeExtendingContext &&
       !Rec.ForRangeLifetimeExtendTemps.empty()) {