[IRGen] Strip marker protocols from type symbol's mangling

Author: xedin

lib/IRGen/IRGenMangler.h

@@ -697,6 +697,9 @@ class IRGenMangler : public Mangle::ASTMangler {
                          llvm::function_ref<void ()> body);
 
   std::string mangleTypeSymbol(Type type, const char *Op) {
+    llvm::SaveAndRestore<bool> savedAllowMarkerProtocols(AllowMarkerProtocols,
+                                                         false);
+
     beginMangling();
     appendType(type, nullptr);
     appendOperator(Op);

test/IRGen/marker_protocol.swift

@@ -14,7 +14,7 @@ extension Int: P { }
 extension Array: P where Element: P { }
 
 // No mention of the marker protocol for runtime type instantiation.
-// CHECK-LABEL: @"$sSS_15marker_protocol1P_ptMD" =
+// CHECK-LABEL: @"$sSS_yptMD" =
 // CHECK-SAME: @"symbolic SS_ypt"
 
 // CHECK-LABEL: @"$s15marker_protocol1QMp" = {{(dllexport |protected )?}}constant
@@ -47,7 +47,7 @@ struct HasMarkers {
 
 // Note: no mention of marker protocols when forming a dictionary.
 // CHECK-LABEL: define{{.*}}@"$s15marker_protocol0A12InDictionaryypyF"
-// CHECK: call ptr @__swift_instantiateConcreteTypeFromMangledName({{.*}} @"$sSS_15marker_protocol1P_ptMD")
+// CHECK: call ptr @__swift_instantiateConcreteTypeFromMangledName({{.*}} @"$sSS_yptMD")
 public func markerInDictionary() -> Any {
   let dict: [String: P] = ["answer" : 42]
   return dict
@@ -85,3 +85,15 @@ protocol P2 {
 
 // CHECK: define{{.*}}$s15marker_protocol3fooyy3FooQz_xtAA1PRzAA2P2RzlF
 func foo<T: P & P2>(_: T.Foo, _: T) { }
+
+class C {}
+
+let v1 = (any C & P).self
+let v2 = C.self
+
+// CHECK-LABEL: define hidden swiftcc void @"$s15marker_protocol23testProtocolCompositionyyF"()
+// CHECK: [[V1:%.*]] = call ptr @__swift_instantiateConcreteTypeFromMangledName(ptr @"$s15marker_protocol1CCMD")
+// CHECK: [[V2:%.*]] = load ptr, ptr @"$s15marker_protocol2v2AA1CCmvp"
+func testProtocolComposition() {
+  print(v1 == v2)
+}

test/Interpreter/protocol_composition_with_markers.swift

@@ -0,0 +1,29 @@
+// RUN: %target-run-simple-swift | %FileCheck %s
+// REQUIRES: executable_test
+
+protocol P {
+  init()
+  func f()
+}
+class C: P {
+  required init() {}
+  func f() { print("C.f") }
+}
+struct G<T: P> {
+  func f() { T().f() }
+}
+
+G<any (C & Sendable)>().f()
+// CHECK: C.f
+
+do {
+  let v1 = (any C & Sendable).self
+  let v2 = C.self
+
+  print(v1)
+  // CHECK: C
+  print(v2)
+  // CHECK: C
+  print(v1 == v2)
+  // CHECK: true
+}