From 8dbe8280aac13766687462a5b3f78f21d7485c7d Mon Sep 17 00:00:00 2001
From: Stuart Montgomery <smontgomery@apple.com>
Date: Wed, 10 Jul 2024 12:45:38 -0500
Subject: [PATCH 1/2] Include try and await expressions which are parents of a
 freestanding expression macro in lexicalContext

Resolves rdar://109470248
---
 .../SwiftSyntaxMacros/Syntax+LexicalContext.swift  | 14 ++++++++++++++
 .../LexicalContextTests.swift                      |  8 +++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift b/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
index 0ba6ddb9216..3a7cb8c7d1b 100644
--- a/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
+++ b/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
@@ -67,6 +67,20 @@ extension SyntaxProtocol {
     case let freestandingMacro as FreestandingMacroExpansionSyntax:
       return Syntax(freestandingMacro.detached) as Syntax
 
+    // Try and await are preserved: A freestanding expression macro preceded
+    // by try or await may need to know whether those keywords are present so it
+    // can propagate them to any expressions in its expansion which were passed
+    // as arguments to the macro. The expression of the try or await is replaced
+    // with a trivial placeholder, though.
+    case var tryExpr as TryExprSyntax:
+      tryExpr = tryExpr.detached
+      tryExpr.expression = "()"
+      return Syntax(tryExpr)
+    case var awaitExpr as AwaitExprSyntax:
+      awaitExpr = awaitExpr.detached
+      awaitExpr.expression = "()"
+      return Syntax(awaitExpr)
+
     default:
       return nil
     }
diff --git a/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift b/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
index 533a2a4d19f..0d94a828b2e 100644
--- a/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
+++ b/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
@@ -531,7 +531,7 @@ final class LexicalContextTests: XCTestCase {
         struct S {
           let arg: C
           var contextDescription: String {
-            #lexicalContextDescription
+            try await #lexicalContextDescription
           }
         }
         return S(arg: c)
@@ -542,7 +542,9 @@ final class LexicalContextTests: XCTestCase {
           struct S {
             let arg: C
             var contextDescription: String {
-              """
+              try await """
+              await ()
+              try ()
               contextDescription: String
               struct S {}
               { c in
@@ -551,7 +553,7 @@ final class LexicalContextTests: XCTestCase {
                 struct S {
                   let arg: C
                   var contextDescription: String {
-                    #lexicalContextDescription
+                    try await #lexicalContextDescription
                   }
                 }
                 return S(arg: c)

From 76d026c102177f87aaa86ea98e908d0f727f88b4 Mon Sep 17 00:00:00 2001
From: Stuart Montgomery <smontgomery@apple.com>
Date: Wed, 10 Jul 2024 13:02:12 -0500
Subject: [PATCH 2/2] Use a wildcard token instead

---
 Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift         | 4 ++--
 Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift b/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
index 3a7cb8c7d1b..1f6ef803179 100644
--- a/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
+++ b/Sources/SwiftSyntaxMacros/Syntax+LexicalContext.swift
@@ -74,11 +74,11 @@ extension SyntaxProtocol {
     // with a trivial placeholder, though.
     case var tryExpr as TryExprSyntax:
       tryExpr = tryExpr.detached
-      tryExpr.expression = "()"
+      tryExpr.expression = ExprSyntax(TypeExprSyntax(type: IdentifierTypeSyntax(name: .wildcardToken())))
       return Syntax(tryExpr)
     case var awaitExpr as AwaitExprSyntax:
       awaitExpr = awaitExpr.detached
-      awaitExpr.expression = "()"
+      awaitExpr.expression = ExprSyntax(TypeExprSyntax(type: IdentifierTypeSyntax(name: .wildcardToken())))
       return Syntax(awaitExpr)
 
     default:
diff --git a/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift b/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
index 0d94a828b2e..6b426aa7431 100644
--- a/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
+++ b/Tests/SwiftSyntaxMacroExpansionTest/LexicalContextTests.swift
@@ -543,8 +543,8 @@ final class LexicalContextTests: XCTestCase {
             let arg: C
             var contextDescription: String {
               try await """
-              await ()
-              try ()
+              await _
+              try _
               contextDescription: String
               struct S {}
               { c in