[Concurrency] Check sendability of the original argument expressions in a call

When checking for the sendability in a call, use the sendability of the
original argument expressions rather than the parameter type, looking
through any implicit conversions that might remove `Sendable`.

Fixes rdar://110763694 / FB12343467.

Author: DougGregor

lib/Sema/TypeCheckConcurrency.cpp

@@ -2674,6 +2674,33 @@ namespace {
       return result;
     }
 
+    /// Find the original type of a value, looking through various implicit
+    /// conversions.
+    static Type findOriginalValueType(Expr *expr) {
+      do {
+        expr = expr->getSemanticsProvidingExpr();
+
+        if (auto inout = dyn_cast<InOutExpr>(expr)) {
+          expr = inout->getSubExpr();
+          continue;
+        }
+
+        if (auto ice = dyn_cast<ImplicitConversionExpr>(expr)) {
+          expr = ice->getSubExpr();
+          continue;
+        }
+
+        if (auto open = dyn_cast<OpenExistentialExpr>(expr)) {
+          expr = open->getSubExpr();
+          continue;
+        }
+
+        break;
+      } while (true);
+
+      return expr->getType()->getRValueType();
+    }
+
     /// Check actor isolation for a particular application.
     bool checkApply(ApplyExpr *apply) {
       auto fnExprType = getType(apply->getFn());
@@ -2857,18 +2884,25 @@ namespace {
 
         // Dig out the location of the argument.
         SourceLoc argLoc = apply->getLoc();
+        Type argType;
         if (auto argList = apply->getArgs()) {
           auto arg = argList->get(paramIdx);
           if (arg.getStartLoc().isValid())
             argLoc = arg.getStartLoc();
+
+          // Determine the type of the argument, ignoring any implicit
+          // conversions that could have stripped sendability.
+          if (Expr *argExpr = arg.getExpr()) {
+            argType = findOriginalValueType(argExpr);
+          }
         }
 
         bool isExiting = !unsatisfiedIsolation->isActorIsolated();
         ActorIsolation diagnoseIsolation = isExiting ? getContextIsolation()
                                                      : *unsatisfiedIsolation;
         if (diagnoseNonSendableTypes(
-                param.getParameterType(), getDeclContext(), argLoc,
-                diag::non_sendable_call_argument,
+                argType ? argType : param.getParameterType(), getDeclContext(),
+                argLoc, diag::non_sendable_call_argument,
                 isExiting, diagnoseIsolation))
           return true;
       }

test/Concurrency/actor_call_implicitly_async.swift

@@ -289,29 +289,29 @@ func blender(_ peeler : () -> Void) {
 
 
   await wisk({})
-  // expected-warning@-1{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-warning@-1{{passing argument of non-sendable type '() -> ()' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
   await wisk(1)
-  // expected-warning@-1{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
   await (peelBanana)()
   await (((((peelBanana)))))()
   await (((wisk)))((wisk)((wisk)(1)))
-  // expected-warning@-1 3{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
 
   blender((peelBanana))
   // expected-warning@-1 2{{converting function value of type '@BananaActor () -> ()' to '() -> Void' loses global actor 'BananaActor'}}
 
   await wisk(peelBanana)
-  // expected-warning@-1{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-warning@-1{{passing argument of non-sendable type '() -> ()' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
 
   await wisk(wisk)
-  // expected-warning@-1{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-warning@-1{{passing argument of non-sendable type '(Any) -> ()' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
   await (((wisk)))(((wisk)))
-  // expected-warning@-1{{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-warning@-1{{passing argument of non-sendable type '(Any) -> ()' into global actor 'BananaActor'-isolated context may introduce data races}}
+  // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
 
-  // expected-warning@+1 {{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
   await {wisk}()(1)
 
-  // expected-warning@+1 {{passing argument of non-sendable type 'Any' into global actor 'BananaActor'-isolated context may introduce data races}}
   await (true ? wisk : {n in return})(1)
 }
 

test/Concurrency/sendable_checking.swift

@@ -216,3 +216,17 @@ class SubWUnsafeSubscript : SuperWUnsafeSubscript {
     }
   }
 }
+
+
+// Test implicit conversions getting in the way
+@available(SwiftStdlib 5.1, *)
+extension MyActor {
+  func f(_: Any) { }
+  func g(_: () -> Void) { }
+}
+
+@available(SwiftStdlib 5.1, *)
+func testConversionsAndSendable(a: MyActor, s: any Sendable, f: @Sendable () -> Void) async {
+  await a.f(s)
+  await a.g(f)
+}