[ClangImporter] Don't put forward-declared structs in the lookup table. (#2610)

Merge pull request #2610 from jrose-apple/cg-import-as-member

Author: jrose-apple

apinotes/CoreGraphics.apinotes

@@ -775,6 +775,24 @@ void ClangImporter::Implementation::addEntryToLookupTable(
   // Determine whether this declaration is suppressed in Swift.
   if (shouldSuppressDeclImport(named)) return;
 
+  // Leave incomplete struct/enum/union types out of the table; Swift only
+  // handles pointers to them.
+  // FIXME: At some point we probably want to be importing incomplete types,
+  // so that pointers to different incomplete types themselves have distinct
+  // types. At that time it will be necessary to make the decision of whether
+  // or not to import an incomplete type declaration based on whether it's
+  // actually the struct backing a CF type:
+  //
+  //    typedef struct CGColor *CGColorRef;
+  //
+  // The best way to do this is probably to change CFDatabase.def to include
+  // struct names when relevant, not just pointer names. That way we can check
+  // both CFDatabase.def and the objc_bridge attribute and cover all our bases.
+  if (auto *tagDecl = dyn_cast<clang::TagDecl>(named)) {
+    if (!tagDecl->getDefinition())
+      return;
+  }
+
   // If we have a name to import as, add this entry to the table.
   if (auto importedName = importFullName(named, None, &clangSema)) {
     table.addEntry(importedName.Imported, named, importedName.EffectiveContext);

lib/ClangImporter/ClangImporter.cpp

@@ -110,3 +110,8 @@ func test_dispatch(_ object: dispatch_object_t) {
   dispatch_retain(object);  // expected-error {{'dispatch_retain' is unavailable}}
   dispatch_release(object); // expected-error {{'dispatch_release' is unavailable}}
 }
+
+func testImportAsMember() {
+  _ = CGColorCreateGenericGray(0.5, 1.0) // expected-error {{'CGColorCreateGenericGray' has been replaced by 'CGColor.init(gray:alpha:)'}} {{7-31=CGColor}} {{32-32=gray: }} {{37-37=alpha: }}
+  _ = CGColor(gray: 0.5, alpha: 1.0)
+}

test/ClangModules/availability.swift

@@ -1,6 +1,6 @@
 typedef const void *CFTypeRef __attribute__((objc_bridge(id)));
 
-typedef const struct __attribute__((objc_bridge(id))) __CCPowerSupply *CCPowerSupplyRef;
+typedef const struct __attribute__((objc_bridge(id))) CCPowerSupply *CCPowerSupplyRef;
 typedef const struct __attribute__((objc_bridge(id))) __CCRefrigerator *CCRefrigeratorRef;
 typedef struct __CCRefrigerator *CCMutableRefrigeratorRef;
 

test/IDE/Inputs/custom-modules/ImportAsMemberC.h

@@ -44,8 +44,6 @@
 // CHECK-NEXT:     TU: SNSomeProtocol
 // CHECK:        UIActionSheet:
 // CHECK-NEXT:     TU: UIActionSheet
-// CHECK-NEXT:   __CCItem:
-// CHECK-NEXT:     TU: __CCItem
 // CHECK-NEXT:   __swift:
 // CHECK-NEXT:     TU: __swift
 // CHECK-NEXT:   accessibilityFloat:

test/IDE/dump_swift_lookup_tables_objc.swift

@@ -35,10 +35,14 @@ public func ==(lhs: CGFloat, rhs: CGFloat) -> Bool {
   return lhs.value == rhs.value
 }
 
-extension CGFloat : IntegerLiteralConvertible, Equatable {
+extension CGFloat : IntegerLiteralConvertible, FloatLiteralConvertible, Equatable {
   public init(integerLiteral value: UnderlyingType) {
     self.value = value
   }
+
+  public init(floatLiteral value: UnderlyingType) {
+    self.value = value
+  }
 }
 
 public extension Double {

test/Inputs/clang-importer-sdk/swift-modules/CoreGraphics.swift

@@ -34,3 +34,5 @@ typedef struct CGRect CGRect;
 typedef CGRect CGRectTy;
 
 typedef struct CGColor *CGColorRef;
+
+CGColorRef CGColorCreateGenericGray(CGFloat gray, CGFloat alpha);