[Swiftify] properly forward inout parameters using &

While we handled prepending & to MutableSpan parameters, regular
parameters that were unchanged during the transformation were not
checked for inout-ness.

Author: hnrklssn

lib/ClangImporter/ImportDecl.cpp

@@ -9552,8 +9552,10 @@ void ClangImporter::Implementation::swiftify(AbstractFunctionDecl *MappedDecl) {
         isa<clang::CXXMethodDecl>(ClangDecl) &&
         !isa<clang::CXXConstructorDecl>(ClangDecl) &&
         cast<clang::CXXMethodDecl>(ClangDecl)->isInstance();
+    size_t swiftNumParams = MappedDecl->getParameters()->size() -
+                            (ClangDecl->isVariadic() ? 1 : 0);
     ASSERT((MappedDecl->isImportAsInstanceMember() == isClangInstanceMethod) ==
-           (ClangDecl->getNumParams() == MappedDecl->getParameters()->size()));
+           (ClangDecl->getNumParams() == swiftNumParams));
 
     size_t selfParamIndex = MappedDecl->isImportAsInstanceMember()
                                 ? MappedDecl->getSelfIndex()

lib/Macros/Sources/SwiftMacros/SwiftifyImportMacro.swift

@@ -468,7 +468,14 @@ struct FunctionCallBuilder: BoundsCheckedThunkBuilder {
     let functionRef = DeclReferenceExprSyntax(baseName: base.name)
     let args: [ExprSyntax] = base.signature.parameterClause.parameters.enumerated()
       .map { (i: Int, param: FunctionParameterSyntax) in
-        return pointerArgs[i] ?? ExprSyntax("\(param.name)")
+        if let overrideArg = pointerArgs[i] {
+          return overrideArg
+        }
+        if isInout(getParam(base.signature, i).type) {
+          return ExprSyntax("&\(param.name)")
+        } else {
+          return ExprSyntax("\(param.name)")
+        }
       }
     let labels: [TokenSyntax?] = base.signature.parameterClause.parameters.map { param in
       let firstName = param.firstName.trimmed

test/Interop/Cxx/swiftify-import/import-as-instance-method.swift

@@ -18,6 +18,8 @@ func foo(_ p: inout MutableSpan<CInt>, a: A, aa: inout A, s: IntSpan, cs: ConstI
   aa.refSelf(&p)
   aa.namespaced(&p)
   b.decapseman(&p)
+  baz.bar(&aa, &p)
+  baz.this(&aa, &p)
 
   let _: IntSpan = unsafe s.spanSelf()
   let _: MutableSpan<CInt> = unsafe s.spanSelf()
@@ -62,6 +64,8 @@ ConstIntSpan constSpanSelf(ConstIntSpan p __lifetimebound) __attribute__((swift_
 namespace baz {
   void namespaced(A *a, IntSpan p __noescape) __attribute__((swift_name("A.namespaced(self:_:)")));
   struct B {};
+  void renamed(A &a, IntSpan p __noescape) __attribute__((swift_name("baz.bar(_:_:)")));
+  void that(A &a, IntSpan p __noescape) __attribute__((swift_name("this(_:_:)")));
 }
 
 void decapseman(baz::B *b, IntSpan p __noescape) __attribute__((swift_name("baz.B.decapseman(self:_:)")));
@@ -169,7 +173,7 @@ public mutating func refSelf(_ p: inout MutableSpan<CInt>) {
 @available(swift, obsoleted: 3, renamed: "A.refSelf(self:_:)") @_alwaysEmitIntoClient @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *) @_lifetime(p: copy p) @_disfavoredOverload
 public func refSelf(_ a: inout A, _ p: inout MutableSpan<CInt>) {
     return unsafe p.withUnsafeMutableBufferPointer { _pPtr in
-      return unsafe refSelf(a, IntSpan(_pPtr))
+      return unsafe refSelf(&a, IntSpan(_pPtr))
     }
 }
 ------------------------------
@@ -213,6 +217,46 @@ public func decapseman(_ b: UnsafeMutablePointer<baz.B>!, _ p: inout MutableSpan
     }
 }
 ------------------------------
+@__swiftmacro_So3bazO8InstanceE3bar15_SwiftifyImportfMp_.swift
+------------------------------
+/// This is an auto-generated wrapper for safer interop
+@_alwaysEmitIntoClient @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *) @_lifetime(p: copy p) @_disfavoredOverload
+public static func bar(_ a: inout A, _ p: inout MutableSpan<CInt>) {
+    return unsafe p.withUnsafeMutableBufferPointer { _pPtr in
+      return unsafe bar(&a, IntSpan(_pPtr))
+    }
+}
+------------------------------
+@__swiftmacro_So3bazO7renamed15_SwiftifyImportfMp_.swift
+------------------------------
+/// This is an auto-generated wrapper for safer interop
+@available(swift, obsoleted: 3, renamed: "baz.bar(_:_:)") @_alwaysEmitIntoClient @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *) @_lifetime(p: copy p) @_disfavoredOverload
+  public static func renamed(_ a: inout A, _ p: inout MutableSpan<CInt>) {
+    return unsafe p.withUnsafeMutableBufferPointer { _pPtr in
+      return unsafe renamed(&a, IntSpan(_pPtr))
+    }
+}
+------------------------------
+@__swiftmacro_So3bazO4this15_SwiftifyImportfMp_.swift
+------------------------------
+/// This is an auto-generated wrapper for safer interop
+@_alwaysEmitIntoClient @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *) @_lifetime(p: copy p) @_disfavoredOverload
+public static func this(_ a: inout A, _ p: inout MutableSpan<CInt>) {
+    return unsafe p.withUnsafeMutableBufferPointer { _pPtr in
+      return unsafe this(&a, IntSpan(_pPtr))
+    }
+}
+------------------------------
+@__swiftmacro_So3bazO4that15_SwiftifyImportfMp_.swift
+------------------------------
+/// This is an auto-generated wrapper for safer interop
+@available(swift, obsoleted: 3, renamed: "this(_:_:)") @_alwaysEmitIntoClient @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *) @_lifetime(p: copy p) @_disfavoredOverload
+  public static func that(_ a: inout A, _ p: inout MutableSpan<CInt>) {
+    return unsafe p.withUnsafeMutableBufferPointer { _pPtr in
+      return unsafe that(&a, IntSpan(_pPtr))
+    }
+}
+------------------------------
 @__swiftmacro_So3stdO3__1O0056spanCInt_CUnsignedLong_18446744073709551615_syGJqopasxheV8InstanceE8spanSelf15_SwiftifyImportfMp_.swift
 ------------------------------
 /// This is an auto-generated wrapper for safer interop