From f898fcfaef448bd3d8b6d28e6a0c9a1e69855428 Mon Sep 17 00:00:00 2001
From: Evan Wilde <ewilde@apple.com>
Date: Tue, 5 Oct 2021 14:12:28 -0700
Subject: [PATCH] $ is not a portable identifier character

As per the C++14 spec, $ can't be used in a portable way in an
identifier name. It falls under the implementation-defined characters
and is allowed by clang. Removing it.
---
 lib/Sema/TypeCheckConcurrency.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/Sema/TypeCheckConcurrency.cpp b/lib/Sema/TypeCheckConcurrency.cpp
index 31258def9874c..791834118f4eb 100644
--- a/lib/Sema/TypeCheckConcurrency.cpp
+++ b/lib/Sema/TypeCheckConcurrency.cpp
@@ -2873,12 +2873,13 @@ getActorIsolationForMainFuncDecl(FuncDecl *fnDecl) {
   ASTContext &ctx = fnDecl->getASTContext();
 
   const bool isMainMain = fnDecl->isMainTypeMainMethod();
-  const bool isMain$Main =
+  const bool isMainInternalMain =
       fnDecl->getBaseIdentifier() == ctx.getIdentifier("$main") &&
       !fnDecl->isInstanceMember() &&
       fnDecl->getResultInterfaceType()->isVoid() &&
       fnDecl->getParameters()->size() == 0;
-  const bool isMainFunction = isMainDeclContext && (isMainMain || isMain$Main);
+  const bool isMainFunction =
+      isMainDeclContext && (isMainMain || isMainInternalMain);
   const bool hasMainActor = !ctx.getMainActorType().isNull();
 
   return isMainFunction && hasMainActor