Member-wise constructor generation with visibility control

source/slang/diff.meta.slang

@@ -1023,9 +1023,14 @@ struct DiffTensorView
     }
 };
 
+// Note: we need `TorchTensorType` so Slang is aware
+// of when we use `TorchTensorType` in a synthisized
+// function. This is important since `[CudaHost]` is 
+// required for any function using `TorchTensorType`
 /// Represents the handle of a Torch tensor object.
 __generic<T>
 __intrinsic_type($(kIROp_TorchTensorType))
+__magic_type(TorchTensorType)
 struct TorchTensor
 {
     __intrinsic_op($(kIROp_TorchTensorGetView))

source/slang/hlsl.meta.slang

@@ -19766,6 +19766,11 @@ struct TextureFootprint<let ND:int> : __TextureFootprintData<ND>
 {
     bool _isSingleLevel;
 
+    __init(__TextureFootprintData<ND> data, bool _isSingleLevelIn)
+    {
+        _isSingleLevel = _isSingleLevelIn;
+    }
+
     property isSingleLevel : bool
     {
         [__NoSideEffect]

source/slang/slang-ast-builder.h

@@ -80,6 +80,15 @@ class SharedASTBuilder : public RefObject
         }
         return m_thisTypeName;
     }
+
+    Name* getCtorName()
+    {
+        if (!m_ctorName)
+        {
+            m_ctorName = getNamePool()->getName("$init");
+        }
+        return m_ctorName;
+    }
 protected:
     // State shared between ASTBuilders
 
@@ -114,6 +123,7 @@ class SharedASTBuilder : public RefObject
     NamePool* m_namePool = nullptr;
 
     Name* m_thisTypeName = nullptr;
+    Name* m_ctorName = nullptr;
 
     // This is a private builder used for these shared types
     ASTBuilder* m_astBuilder = nullptr;

source/slang/slang-ast-decl.h

@@ -367,14 +367,30 @@ class FunctionDeclBase : public CallableDecl
     Stmt* body = nullptr;
 };
 
+enum class ConstructorTags : int
+{
+    None = 0,
+
+    /// Indicates whether the declaration was synthesized by
+    /// Slang and not actually provided by the user
+    Synthesized = 1 << 0,
+
+    /// Derived classes will call this ctor if they need a memberwise ctor for public members.
+    MemberwiseCtorForPublicVisibility = 1 << 1,    
+
+    /// Derived classes will call this ctor if they need a memberwise ctor for public and internal members.
+    /// A ctor with `MemberwiseCtorForInternalVisibility` may also contain 'isMemberwiseCtorForPublicVisibility'
+    MemberwiseCtorForInternalVisibility = 1 << 2,
+};
+
 // A constructor/initializer to create instances of a type
 class ConstructorDecl : public FunctionDeclBase
 {
     SLANG_AST_CLASS(ConstructorDecl)
 
-    // Indicates whether the declaration was synthesized by
-    // slang and not actually provided by the user
-    bool isSynthesized = false;
+    int options = (int)ConstructorTags::None;
+    void addOption(ConstructorTags option) { options |= (int)option; }
+    bool containsOption(ConstructorTags option) { return options & (int)option; }
 };
 
 // A subscript operation used to index instances of a type

source/slang/slang-ast-modifier.h

@@ -38,6 +38,9 @@ class ToBeSynthesizedModifier : public Modifier {SLANG_AST_CLASS(ToBeSynthesized
 // Marks that the definition of a decl is synthesized.
 class SynthesizedModifier : public Modifier { SLANG_AST_CLASS(SynthesizedModifier) };
 
+// Marks that the definition of a decl is our $DefaultInit function.
+class DefaultInitModifier : public Modifier { SLANG_AST_CLASS(DefaultInitModifier) };
+
 // Marks a synthesized variable as local temporary variable.
 class LocalTempVarModifier : public Modifier { SLANG_AST_CLASS(LocalTempVarModifier) };
 

source/slang/slang-ast-support-types.h

@@ -470,7 +470,6 @@ namespace Slang
             /// functions, so it belongs in the last phase of checking.
             ///
         DefinitionChecked,
-        DefaultConstructorReadyForUse = DefinitionChecked,
 
             /// The capabilities required by the decl is infered and validated.
             ///
@@ -491,6 +490,8 @@ namespace Slang
         CanUseFuncSignature = ReadyForReference,
         CanSpecializeGeneric = ReadyForReference,
         CanReadInterfaceRequirements = ReadyForLookup,
+        DefaultConstructorReadyForUse = ReadyForConformances,
+        VarInitExprAreChecked = DefinitionChecked,
     };
 
         /// A `DeclCheckState` plus a bit to track whether a declaration is currently being checked.

source/slang/slang-ast-type.h

@@ -523,6 +523,11 @@ class TensorViewType : public BuiltinType
     Type* getElementType();
 };
 
+class TorchTensorType : public BuiltinType
+{
+    SLANG_AST_CLASS(TorchTensorType)
+};
+
 // Base class for built in string types
 class StringTypeBase : public BuiltinType
 {