[Swiftify] Don't create safe wrapper for autoreleasing pointers (swiftlang#81568)

_SwiftifyImport doesn't know how to handle
AutoreleasingUnsafeMutablePointer, so we should not attach any
.countedBy information for pointers that are imported as this type.

This also adds defensive checks against adding .countedBy to any pointer
type that _SwiftifyImport doesn't know how to transform.

rdar://151479521

Author: hnrklssn

lib/ClangImporter/ImportDecl.cpp

@@ -9192,6 +9192,14 @@ static bool SwiftifiableCAT(const clang::CountAttributedType *CAT) {
   return CAT && CountedByExpressionValidator().Visit(CAT->getCountExpr());
 }
 
+static bool SwiftifiablePointerType(Type swiftType) {
+  // don't try to transform any Swift types that _SwiftifyImport doesn't know how to handle
+  Type nonnullType = swiftType->lookThroughSingleOptionalType();
+  PointerTypeKind PTK;
+  return nonnullType->isOpaquePointer() ||
+    (nonnullType->getAnyPointerElementType(PTK) && PTK != PTK_AutoreleasingUnsafeMutablePointer);
+}
+
 void ClangImporter::Implementation::swiftify(FuncDecl *MappedDecl) {
   if (!SwiftContext.LangOpts.hasFeature(Feature::SafeInteropWrappers))
     return;
@@ -9225,10 +9233,11 @@ void ClangImporter::Implementation::swiftify(FuncDecl *MappedDecl) {
           return false;
         };
     SwiftifyInfoPrinter printer(getClangASTContext(), SwiftContext, out);
+    Type swiftReturnTy = MappedDecl->getResultInterfaceType();
     bool returnIsStdSpan = registerStdSpanTypeMapping(
-        MappedDecl->getResultInterfaceType(), ClangDecl->getReturnType());
+        swiftReturnTy, ClangDecl->getReturnType());
     auto *CAT = ClangDecl->getReturnType()->getAs<clang::CountAttributedType>();
-    if (SwiftifiableCAT(CAT)) {
+    if (SwiftifiableCAT(CAT) && SwiftifiablePointerType(swiftReturnTy)) {
       printer.printCountedBy(CAT, SwiftifyInfoPrinter::RETURN_VALUE_INDEX);
       attachMacro = true;
     }
@@ -9242,14 +9251,15 @@ void ClangImporter::Implementation::swiftify(FuncDecl *MappedDecl) {
     for (auto [index, clangParam] : llvm::enumerate(ClangDecl->parameters())) {
       auto clangParamTy = clangParam->getType();
       auto swiftParam = MappedDecl->getParameters()->get(index);
+      Type swiftParamTy = swiftParam->getInterfaceType();
       bool paramHasBoundsInfo = false;
       auto *CAT = clangParamTy->getAs<clang::CountAttributedType>();
-      if (SwiftifiableCAT(CAT)) {
+      if (SwiftifiableCAT(CAT) && SwiftifiablePointerType(swiftParamTy)) {
         printer.printCountedBy(CAT, index);
         attachMacro = paramHasBoundsInfo = true;
       }
       bool paramIsStdSpan = registerStdSpanTypeMapping(
-          swiftParam->getInterfaceType(), clangParamTy);
+          swiftParamTy, clangParamTy);
       paramHasBoundsInfo |= paramIsStdSpan;
 
       bool paramHasLifetimeInfo = false;
@@ -9260,7 +9270,7 @@ void ClangImporter::Implementation::swiftify(FuncDecl *MappedDecl) {
       if (clangParam->hasAttr<clang::LifetimeBoundAttr>()) {
         printer.printLifetimeboundReturn(
             index, !paramHasBoundsInfo &&
-                       swiftParam->getInterfaceType()->isEscapable());
+                       swiftParamTy->isEscapable());
         paramHasLifetimeInfo = true;
         returnHasLifetimeInfo = true;
       }

test/Interop/C/swiftify-import/Inputs/module.modulemap

@@ -14,4 +14,3 @@ module SizedByNoEscapeClang {
     header "sized-by-noescape.h"
     export *
 }
-

test/Interop/ObjC/lit.local.cfg

@@ -0,0 +1,2 @@
+if 'objc_interop' not in config.available_features:
+    config.unsupported = True

test/Interop/ObjC/swiftify-import/Inputs/module.modulemap

@@ -0,0 +1,4 @@
+module NoSwiftifyClang {
+    header "objc-no-swiftify.h"
+    export *
+}

test/Interop/ObjC/swiftify-import/Inputs/objc-no-swiftify.h

@@ -0,0 +1,9 @@
+#define __counted_by(x) __attribute__((__counted_by__(x)))
+
+@interface SomeClass
+- (int)numberOfSegments;
+@end
+
+void autoreleaseParam(SomeClass * __autoreleasing * __counted_by(len) p, int len); // expected-note{{declared here}}
+
+SomeClass * __autoreleasing * __counted_by(len) autoreleaseReturn(int len);

test/Interop/ObjC/swiftify-import/counted-by-in-class.swift

@@ -5,8 +5,6 @@
 // RUN: %target-swift-ide-test -plugin-path %swift-plugin-dir -I %t/Inputs -enable-experimental-feature SafeInteropWrappers -print-module -module-to-print=Method -source-filename=x | %FileCheck %s
 // RUN: %target-swift-frontend -plugin-path %swift-plugin-dir -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/method.swift -dump-macro-expansions -typecheck -verify
 
-// REQUIRES: objc_interop
-
 // CHECK: class Foo {
 // CHECK:  func bar(_ p: UnsafeMutableBufferPointer<Float>)
 

test/Interop/ObjC/swiftify-import/objc-no-swiftify.swift

@@ -0,0 +1,22 @@
+// REQUIRES: swift_feature_SafeInteropWrappers
+
+// RUN: %target-swift-ide-test -print-module -module-to-print=NoSwiftifyClang -plugin-path %swift-plugin-dir -I %S/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s
+
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -plugin-path %swift-plugin-dir -o %t/NoSwiftify.swiftmodule -I %S/Inputs -enable-experimental-feature SafeInteropWrappers %s -verify -verify-additional-file %S/Inputs/objc-no-swiftify.h
+
+import NoSwiftifyClang
+
+// CHECK-NOT: @_alwaysEmitIntoClient public func callAutoreleaseParam
+// CHECK-NOT: @_alwaysEmitIntoClient public func callAutoreleaseReturn
+
+public func callAutoreleaseParam(_ p: UnsafeMutableBufferPointer<SomeClass>) {
+    // expected-error@+2{{missing argument for parameter #2 in call}}
+    // expected-error@+1{{cannot convert value of type 'UnsafeMutableBufferPointer<SomeClass>' to expected argument type 'AutoreleasingUnsafeMutablePointer<SomeClass?>'}}
+    autoreleaseParam(p)
+}
+
+public func callAutoreleaseReturn() {
+    // expected-error@+1{{cannot convert value of type 'AutoreleasingUnsafeMutablePointer<SomeClass?>?' to specified type 'UnsafeMutableBufferPointer<SomeClass>'}}
+    let p: UnsafeMutableBufferPointer<SomeClass> = autoreleaseReturn(10)
+}