3 files changed, 83 insertions, 1 deletions

diff --git a/source/slang/reflection.cpp b/source/slang/reflection.cpp
index 4ac48d2e7..4d13052f6 100644
--- a/source/slang/reflection.cpp
+++ b/source/slang/reflection.cpp
@@ -279,6 +279,10 @@ SLANG_API SlangTypeKind spReflectionType_GetKind(SlangReflectionType* inType)
             return SLANG_TYPE_KIND_INTERFACE;
         }
     }
+    else if( auto specializedType = as<ExistentialSpecializedType>(type) )
+    {
+        return SLANG_TYPE_KIND_SPECIALIZED;
+    }
     else if (auto errorType = as<ErrorType>(type))
     {
         // This means we saw a type we didn't understand in the user's code
@@ -746,6 +750,10 @@ SLANG_API SlangReflectionTypeLayout* spReflectionTypeLayout_GetElementTypeLayout
     {
         return convert(structuredBufferTypeLayout->elementTypeLayout.Ptr());
     }
+    else if( auto specializedTypeLayout = as<ExistentialSpecializedTypeLayout>(typeLayout) )
+    {
+        return convert(specializedTypeLayout->baseTypeLayout.Ptr());
+    }
 
     return nullptr;
 }
@@ -878,6 +886,22 @@ SLANG_API SlangReflectionVariableLayout* spReflectionVariableLayout_getPendingDa
     return convert(pendingDataLayout);
 }
 
+SLANG_API SlangReflectionVariableLayout* spReflectionTypeLayout_getSpecializedTypePendingDataVarLayout(SlangReflectionTypeLayout* inTypeLayout)
+{
+    auto typeLayout = convert(inTypeLayout);
+    if(!typeLayout) return nullptr;
+
+    if( auto specializedTypeLayout = as<ExistentialSpecializedTypeLayout>(typeLayout) )
+    {
+        auto pendingDataVarLayout = specializedTypeLayout->pendingDataVarLayout.Ptr();
+        return convert(pendingDataVarLayout);
+    }
+    else
+    {
+        return nullptr;
+    }
+}
+
 
 // Variable Reflection
 
diff --git a/source/slang/type-layout.cpp b/source/slang/type-layout.cpp
index e315c2fb6..ba6085e0a 100644
--- a/source/slang/type-layout.cpp
+++ b/source/slang/type-layout.cpp
@@ -2210,7 +2210,11 @@ RefPtr<VarLayout> StructTypeLayoutBuilder::addField(
     fieldLayout->varDecl = field;
     fieldLayout->typeLayout = fieldTypeLayout;
     m_typeLayout->fields.add(fieldLayout);
-    m_typeLayout->mapVarToLayout.Add(field.getDecl(), fieldLayout);
+
+    if( field )
+    {
+        m_typeLayout->mapVarToLayout.Add(field.getDecl(), fieldLayout);
+    }
 
     // Set up uniform offset information, if there is any uniform data in the field
     if( fieldTypeLayout->FindResourceInfo(LayoutResourceKind::Uniform) )
@@ -2948,6 +2952,52 @@ static TypeLayoutResult _createTypeLayout(
 
         return TypeLayoutResult(taggedUnionLayout, info);
     }
+    else if( auto existentialSpecializedType = as<ExistentialSpecializedType>(type) )
+    {
+        TypeLayoutContext subContext = context.withExistentialTypeArgs(
+            existentialSpecializedType->slots.args.getCount(),
+            existentialSpecializedType->slots.args.getBuffer());
+
+        auto baseTypeLayoutResult = _createTypeLayout(
+            subContext,
+            existentialSpecializedType->baseType);
+
+        UniformLayoutInfo info = rules->BeginStructLayout();
+        rules->AddStructField(&info, baseTypeLayoutResult.info.getUniformLayout());
+
+        RefPtr<ExistentialSpecializedTypeLayout> typeLayout = new ExistentialSpecializedTypeLayout();
+        typeLayout->type = type;
+        typeLayout->rules = rules;
+
+        RefPtr<VarLayout> pendingDataVarLayout = new VarLayout();
+        if(auto pendingDataTypeLayout = baseTypeLayoutResult.layout->pendingDataTypeLayout)
+        {
+            for( auto pendingResInfo : pendingDataTypeLayout->resourceInfos )
+            {
+                auto kind = pendingResInfo.kind;
+                UInt index = 0;
+                if( kind == LayoutResourceKind::Uniform )
+                {
+                    LayoutSize uniformOffset = rules->AddStructField(
+                        &info,
+                        makeTypeLayoutResult(pendingDataTypeLayout).info.getUniformLayout());
+
+                    index = uniformOffset.getFiniteValue();
+                }
+                else
+                {
+                    if(auto primaryResInfo = baseTypeLayoutResult.layout->FindResourceInfo(kind))
+                        index = primaryResInfo->count.getFiniteValue();
+                }
+                pendingDataVarLayout->AddResourceInfo(kind)->index = index;
+            }
+        }
+
+        typeLayout->baseTypeLayout = baseTypeLayoutResult.layout;
+        typeLayout->pendingDataVarLayout = pendingDataVarLayout;
+
+        return makeTypeLayoutResult(typeLayout);
+    }
 
     // catch-all case in case nothing matched
     SLANG_ASSERT(!"unimplemented case in type layout");
diff --git a/source/slang/type-layout.h b/source/slang/type-layout.h
index fcb2c3419..c58f92cfb 100644
--- a/source/slang/type-layout.h
+++ b/source/slang/type-layout.h
@@ -630,6 +630,14 @@ public:
     LayoutSize tagOffset;
 };
 
+    /// Layout information for a type with existential (sub-)field types specialized.
+class ExistentialSpecializedTypeLayout : public TypeLayout
+{
+public:
+    RefPtr<TypeLayout> baseTypeLayout;
+    RefPtr<VarLayout> pendingDataVarLayout;
+};
+
     /// Layout for a scoped entity like a program, module, or entry point
 class ScopeLayout : public Layout
 {