Fix for unscoped enums circular reference causing an error, #3959 (#3962)

2 files changed, 11 insertions, 4 deletions

diff --git a/source/slang/slang-check-decl.cpp b/source/slang/slang-check-decl.cpp
index d35502235..131d30d98 100644
--- a/source/slang/slang-check-decl.cpp
+++ b/source/slang/slang-check-decl.cpp
@@ -2380,8 +2380,15 @@ namespace Slang
     {
         // check the type being inherited from
         auto base = inheritanceDecl->base;
-        CheckConstraintSubType(base);
-        base = TranslateTypeNode(base);
+        Decl* toExclude = nullptr;
+        Decl* parent = getParentDecl(inheritanceDecl);
+        // We exclude in the case that a circular reference is possible. This is when a parent is a transparent decl.
+        // If we just blanket "block" all ensure's of a parent a generic may fail when trying to fetch a parent
+        if (parent->findModifier<TransparentModifier>())
+            toExclude = parent;
+        SemanticsDeclVisitorBase baseVistor(this->withDeclToExcludeFromLookup(toExclude));
+        baseVistor.CheckConstraintSubType(base);
+        base = baseVistor.TranslateTypeNode(base);
         inheritanceDecl->base = base;
 
         // Note: we do not check whether the type being inherited from
diff --git a/source/slang/slang-lookup.cpp b/source/slang/slang-lookup.cpp
index 2be9d29e8..9c8b2fa0b 100644
--- a/source/slang/slang-lookup.cpp
+++ b/source/slang/slang-lookup.cpp
@@ -224,13 +224,13 @@ static void _lookUpDirectAndTransparentMembers(
         }
     }
 
-    // TODO(tfoley): should we look up in the transparent decls
-    // if we already has a hit in the current container?
     for(auto transparentInfo : containerDecl->getTransparentMembers())
     {
         // The reference to the transparent member should use the same
         // path as we used in referring to its parent.
         DeclRef<Decl> transparentMemberDeclRef = astBuilder->getMemberDeclRef(parentDeclRef, transparentInfo.decl);
+        if (transparentMemberDeclRef.getDecl() == request.declToExclude)
+            continue;
 
         // We need to leave a breadcrumb so that we know that the result
         // of lookup involves a member lookup step here