Stub out basic tests for future extensions

We eventually want to be able to implement functions imported as globals or members in Swift, but we’re not there yet. Add some basic tests to make sure we get reasonable diagnostics for them.

Author: beccadax

test/decl/ext/Inputs/objc_implementation.h

@@ -192,6 +192,13 @@ _Nonnull id CImplFuncMismatch6a(int param);
 void CImplFuncNameMismatch1(int param);
 void CImplFuncNameMismatch2(int param);
 
+int CImplGetComputedGlobal1(void) __attribute__((swift_name("getter:cImplComputedGlobal1()")));
+void CImplSetComputedGlobal1(int param) __attribute__((swift_name("setter:cImplComputedGlobal1(newValue:)")));
+
+typedef struct CImplStruct {} CImplStruct;
+
+void CImplStructStaticFunc1(int param) __attribute__((swift_name("CImplStruct.staticFunc1(_:)")));
+
 struct ObjCStruct {
   int foo;
 };

test/decl/ext/objc_implementation.swift

@@ -464,6 +464,10 @@ protocol EmptySwiftProto {}
   // expected-error@-1 {{'@_objcImplementation' cannot be used to implement generic class 'ObjCImplGenericClass'}}
 }
 
+//
+// @_cdecl for global functions
+//
+
 @_objcImplementation @_cdecl("CImplFunc1")
 func CImplFunc1(_: Int32) {
   // OK
@@ -542,6 +546,38 @@ func CImplFuncNameMismatch2(_: Int32) {
   // FIXME: Improve diagnostic for a partial match.
 }
 
+//
+// TODO: @_cdecl for global functions imported as computed vars
+//
+var cImplComputedGlobal1: Int32 {
+  @_objcImplementation @_cdecl("CImplGetComputedGlobal1")
+  get {
+    // FIXME: Lookup for vars isn't working yet
+    // expected-error@-3 {{could not find imported function 'CImplGetComputedGlobal1' matching getter for var 'cImplComputedGlobal1'; make sure your umbrella or bridging header imports the header that declares it}}
+    return 0
+  }
+
+  @_objcImplementation @_cdecl("CImplSetComputedGlobal1")
+  set {
+    // FIXME: Lookup for vars isn't working yet
+    // expected-error@-3 {{could not find imported function 'CImplSetComputedGlobal1' matching setter for var 'cImplComputedGlobal1'; make sure your umbrella or bridging header imports the header that declares it}}
+    print(newValue)
+  }
+}
+
+//
+// TODO: @_cdecl for import-as-member functions
+//
+extension CImplStruct {
+  @_objcImplementation @_cdecl("CImplStructStaticFunc1")
+  static func staticFunc1(_: Int32) {
+    // FIXME: Add underlying support for this
+    // expected-error@-3 {{@_cdecl can only be applied to global functions}}
+    // FIXME: Lookup in an enclosing type is not working yet
+    // expected-error@-5 {{could not find imported function 'CImplStructStaticFunc1' matching static method 'staticFunc1'; make sure your umbrella or bridging header imports the header that declares it}}
+  }
+}
+
 func usesAreNotAmbiguous(obj: ObjCClass) {
   obj.method(fromHeader1: 1)
   obj.method(fromHeader2: 2)