Arguments are weird

Author: ApolloZhu

test/Macros/Inputs/syntax_macro_definitions.swift

@@ -2043,13 +2043,36 @@ public struct ClosureCallerMacro: ExpressionMacro {
     }
 }
 
-public struct FirstArgumentConcatStringMacro: ExpressionMacro {
+public struct PrependHelloMacro: ExpressionMacro {
     public static func expansion(
       of node: some FreestandingMacroExpansionSyntax,
       in context: some MacroExpansionContext
     ) -> ExprSyntax {
         """
-        \(node.arguments.first!.expression) + " world"
+        "hello " + \(node.arguments.first!.expression)
+        """
+    }
+}
+
+public struct AsIsMacro: ExpressionMacro {
+    public static func expansion(
+      of node: some FreestandingMacroExpansionSyntax,
+      in context: some MacroExpansionContext
+    ) -> ExprSyntax {
+        node.arguments.first!.expression
+    }
+}
+
+public struct IntroduceShadowedMacro: ExpressionMacro {
+    public static func expansion(
+      of node: some FreestandingMacroExpansionSyntax,
+      in context: some MacroExpansionContext
+    ) -> ExprSyntax {
+        """
+        {
+            let shadowed = "from shadow"
+            return \(node.arguments.first!.expression)
+        }()
         """
     }
 }

test/Macros/Inputs/with_macro_default_arg_interface.swift

@@ -4,8 +4,18 @@ public macro FileID<T: ExpressibleByStringLiteral>() -> T = #externalMacro(
 )
 
 @freestanding(expression)
-public macro HasParam(_ param: String) -> String = #externalMacro(
-    module: "MacroDefinition", type: "FirstArgumentConcatStringMacro"
+public macro PrependHello(_ param: String) -> String = #externalMacro(
+    module: "MacroDefinition", type: "PrependHelloMacro"
+)
+
+@freestanding(expression)
+public macro AsIs<T>(_ param: T) -> T = #externalMacro(
+    module: "MacroDefinition", type: "AsIsMacro"
+)
+
+@freestanding(expression)
+public macro IntroduceShadowed<T>(_ param: T) -> T = #externalMacro(
+    module: "MacroDefinition", type: "IntroduceShadowedMacro"
 )
 
 @freestanding(expression)
@@ -31,10 +41,28 @@ public struct ClosureCaller {
     }
 }
 
-public let shadowed = "hello"
+public let shadowed = "world"
 
 public func testParameterUseVariableFromOriginalDeclContext(
-    param: String = #HasParam(shadowed)
+    param: String = #PrependHello(shadowed)
+) {
+    print(param)
+}
+
+public func testMacroUseMacro(
+    param: String = #PrependHello(#fileID)
+) {
+    print(param)
+}
+
+public func testUseShadowedFromOuterExpansion(
+    param: String = #IntroduceShadowed(#PrependHello(shadowed))
+) {
+    print(param)
+}
+
+public func testNestedStillInOriginalDeclContext(
+    param: String = #AsIs(#PrependHello(shadowed))
 ) {
     print(param)
 }

test/Macros/macro_default_argument_enabled.swift

@@ -112,6 +112,17 @@ let printWithFileLine = buildPrinter { }
             testParameterUseVariableFromOriginalDeclContext()
         }
 
+        do {
+            let shadowed: String = "not this either"
+            // CHECK: hello world
+            testNestedStillInOriginalDeclContext()
+        }
+        
+        // CHECK: hello from shadow
+        testUseShadowedFromOuterExpansion()
+        // CHECK: hello MacroUser/macro_default_argument_enabled.swift
+        testMacroUseMacro()
+        
         // CHECK: [[# @LINE + 1]]
         asDefaultArgument()
         // CHECK: [[# @LINE + 1]]