[NFC, Scoped Enum] Convert Sema::ExpressionEvaluationContext into a scoped Enum

- also replace direct equality checks against the ConstantEvaluated enumerator  with isConstantEvaluted(), in anticipation of adding finer granularity to the various ConstantEvaluated contexts and reinstating certain restrictions on where lambda expressions can occur in C++17.

- update the clang tablegen backend that uses these Enumerators, and add the relevant scope where needed.

llvm-svn: 299316

1 files changed, 8 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 174f750ab6b..85ff3a1e082 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4589,7 +4589,8 @@ static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc,
 
     // Perform the initialization in an unevaluated context within a SFINAE
     // trap at translation unit scope.
-    EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated);
+    EnterExpressionEvaluationContext Unevaluated(
+        S, Sema::ExpressionEvaluationContext::Unevaluated);
     Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
     Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
     InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0]));
@@ -4765,7 +4766,8 @@ static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
 
     // Perform the initialization in an unevaluated context within a SFINAE
     // trap at translation unit scope.
-    EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
+    EnterExpressionEvaluationContext Unevaluated(
+        Self, Sema::ExpressionEvaluationContext::Unevaluated);
     Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
     Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
     InitializationSequence Init(Self, To, Kind, FromPtr);
@@ -4816,7 +4818,8 @@ static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
 
     // Attempt the assignment in an unevaluated context within a SFINAE
     // trap at translation unit scope.
-    EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
+    EnterExpressionEvaluationContext Unevaluated(
+        Self, Sema::ExpressionEvaluationContext::Unevaluated);
     Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
     Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
     ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
@@ -6726,7 +6729,8 @@ ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
       // follows the normal lifetime rules for block literals instead of being
       // autoreleased.
       DiagnosticErrorTrap Trap(Diags);
-      PushExpressionEvaluationContext(PotentiallyEvaluated);
+      PushExpressionEvaluationContext(
+          ExpressionEvaluationContext::PotentiallyEvaluated);
       ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(),
                                                      E->getExprLoc(),
                                                      Method, E);