SIL: add var Argument.decl: ValueDecl?

Author: eeckstein

SwiftCompilerSources/Sources/AST/Declarations.swift

@@ -157,3 +157,9 @@ extension OptionalBridgedDeclObj {
   public var decl: Decl? { obj.getAs(Decl.self) }
   public func getAs<T: Decl>(_ declType: T.Type) -> T? { obj.getAs(T.self) }
 }
+
+extension Optional where Wrapped == Decl {
+  public var bridged: OptionalBridgedDeclObj {
+    OptionalBridgedDeclObj(self?.bridged.obj)
+  }
+}

SwiftCompilerSources/Sources/SIL/Argument.swift

@@ -34,8 +34,10 @@ public class Argument : Value, Hashable {
 
   public var isLexical: Bool { false }
 
+  public var decl: ValueDecl? { bridged.getDecl().getAs(ValueDecl.self) }
+
   public func findVarDecl() -> VarDecl? {
-    if let varDecl = bridged.getVarDecl().getAs(VarDecl.self) {
+    if let varDecl = decl as? VarDecl {
       return varDecl
     }
     return findVarDeclFromDebugUsers()

include/swift/AST/ASTBridging.h

@@ -370,6 +370,16 @@ void registerBridgedDecl(BridgedStringRef bridgedClassName, SwiftMetatype metaty
 
 struct OptionalBridgedDeclObj {
   OptionalSwiftObject obj;
+
+  OptionalBridgedDeclObj(OptionalSwiftObject obj) : obj(obj) {}
+
+#ifdef USED_IN_CPP_SOURCE
+  template <class D> D *_Nullable getAs() const {
+    if (obj)
+      return llvm::cast<D>(static_cast<swift::Decl *>(obj));
+    return nullptr;
+  }
+#endif
 };
 
 struct BridgedDeclObj {

include/swift/SIL/SILBridging.h

@@ -903,7 +903,7 @@ struct BridgedArgument {
   BRIDGED_INLINE bool FunctionArgument_isLexical() const;
   BRIDGED_INLINE bool FunctionArgument_isClosureCapture() const;
   BRIDGED_INLINE void setReborrow(bool reborrow) const;
-  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getVarDecl() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getDecl() const;
   BRIDGED_INLINE void copyFlags(BridgedArgument fromArgument) const;
 };
 

include/swift/SIL/SILBridgingImpl.h

@@ -593,8 +593,8 @@ bool BridgedArgument::FunctionArgument_isClosureCapture() const {
     getArgument())->isClosureCapture();
 }
 
-OptionalBridgedDeclObj BridgedArgument::getVarDecl() const {
-  return {llvm::dyn_cast_or_null<swift::VarDecl>(getArgument()->getDecl())};
+OptionalBridgedDeclObj BridgedArgument::getDecl() const {
+  return {getArgument()->getDecl()};
 }
 
 void BridgedArgument::copyFlags(BridgedArgument fromArgument) const {