I have a Swift Package that contains an Objective-C target. The target contains Objective-C literals but unfortunately the compiler says "Initializer element is not a compile-time constant", what am I doing wrong?
Based on the error triggering in the upper half, I take it that objc_array_literals is on.
My target definition looks like:
.target(
name: "MyTarget",
path: "Sources/MySourcesObjC",
publicHeadersPath: "include",
cxxSettings: [
.unsafeFlags("-fobjc-constant-literals")
]
),
I believe Objective-C literals are enabled since a long time but I still tried passing in the -fobjc-constant-literals flag and no luck.
To be clear I'm not interested in a run-time initialization, I really want it to be compile time. Does anyone know what I can do?
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I've been teaching myself Objective-C and I wanted to start creating projects that don't use ARC to become better at memory management and learn how it all works. I've been attempting to build and run applications, but I'm not really sure where to start as modern iOS development is used with Swift and memory management is handled.
Is there any way to create modern applications that use Objective-C, UIKit, and not use ARC?
At least with macOS Sequoia 15.5 and Xcode 16.3:
$ cat test.cc
#include <locale.h>
#include <string.h>
#include <xlocale.h>
int main(void) {
locale_t l = newlocale(LC_ALL_MASK, "el_GR.UTF-8", 0);
strxfrm_l(NULL, "ό", 0, l);
return 0;
}
$ c99 test.c && ./a.out
Assertion failed: (p->val == key), function lookup_substsearch, file collate.c, line 596.
Abort trap: 6
Just read about the new @concurrent option coming to Swift 6.2 and lover it, but...
It just me, but I which these options would pick a case and stick with it...
@Sendable
@unchecked
@MainActor
@concurrent
@Observable
@ObservationIgnored
I have an @objC used for notification.
kTag is an Int constant, fieldBeingEdited is an Int variable.
The following code fails at compilation with error: Command CompileSwift failed with a nonzero exit code if I capture self (I edited code, to have minimal case)
@objc func keyboardDone(_ sender : UIButton) {
DispatchQueue.main.async { [self] () -> Void in
switch fieldBeingEdited {
case kTag : break
default : break
}
}
}
If I explicitly use self, it compiles, even with self captured:
@objc func keyboardDone(_ sender : UIButton) {
DispatchQueue.main.async { [self] () -> Void in
switch fieldBeingEdited { // <<-- no need for self here
case self.kTag : break // <<-- self here
default : break
}
}
}
This compiles as well:
@objc func keyboardDone(_ sender : UIButton) {
DispatchQueue.main.async { () -> Void in
switch self.fieldBeingEdited { // <<-- no need for self here
case self.kTag : break // <<-- self here
default : break
}
}
}
Is it a compiler bug or am I missing something ?
This is not a question but more of a hint where I was having trouble with. In my SwiftData App I wanted to move from Swift 5 to Swift 6, for that, as recommended, I stayed in Swift 5 language mode and set 'Strict Concurrency Checking' to 'Complete' within my build settings.
It marked all the places where I was using predicates with the following warning:
Type '' does not conform to the 'Sendable' protocol; this is an error in the Swift 6 language mode
I had the same warnings for SortDescriptors.
I spend quite some time searching the web and wrapping my head around how to solve that issue to be able to move to Swift 6. In the end I found this existing issue in the repository of the Swift Language https://github.com/swiftlang/swift/issues/68943. It says that this is not a warning that should be seen by the developer and in fact when turning Swift 6 language mode on those issues are not marked as errors.
So if anyone is encountering this when trying to fix all issues while staying in Swift 5 language mode, ignore those, fix the other issues and turn on Swift 6 language mode and hopefully they are gone.
Hello guys!
I faced a problem with building...
My device suddenly updated to iOS 15.4.1, my Xcode was 13.2 and I had to update it to the latest version (13.3.1) to build the app. After the update, I had a few problems which were successfully solved but one of them stopped me for a few hours. The problem is with Bridging Headers or Swift Compiler, I really don't know what I did badly, and what causes problems.
On several forums I often read that is important to set:
Build Settings > Build Options > Build Libraries for Distribution
But in any case it doesn't work, on yes:
error: using bridging headers with module interfaces is unsupported
on no:
(line with import framework SWXMLHash) /Users/blablabla/SSLModel.swift:9:8: error: module compiled with Swift 5.5.1 cannot be imported by the Swift 5.6 compiler: /Users/blablabla2/Build/Products/Debug-iphoneos/SWXMLHash.framework/Modules/SWXMLHash.swiftmodule/arm64-apple-ios.swiftmodule
import SWXMLHash
It will be important that I use Carthage.
What should I do?
Clone all 10 frameworks that I use and re-build them with a new Xcode which includes compiler 5.6? That may be a bad solution... Any answers on similar topics don't help..
I came across
One Sided Range
Example:
[...2]
[2...]
[..<2]
Half Open Range
[..<2]
Can not the last use case be separated [..<2] of One Sided Range for Brevity as it is already included in Half Open Range?
I’m aware that Xcode version 26 beta 3 provides an option to enable Swift’s Approachable Concurrency feature at the project level. However, I’d like to achieve the same for a Swift Package. Could you please advise on how to enable Approachable Concurrency support specifically for a Swift Package?
I want to understand what the recommended way is for string interoperability between swift and c++. Below are the 3 ways to achieve it. Approach 2 is not allowed at work due to restrictions with using std libraries.
Approach 1:
In C++:
char arr[] = "C++ String";
void * cppstring = arr;
std::cout<<"before:"<<(char*)cppstring<<std::endl; // C++ String
// calling swift function and passing the void buffer to it, so that swift can update the buffer content
Module1::SwiftClass:: ReceiveString (cppstring, length);
std::cout<<"after:"<<(char*)cppstring<<std::endl; // SwiftStr
In Swift:
func ReceiveString (pBuffer : UnsafeMutableRawPointer , pSize : UInt ) -> Void
{
// to convert cpp-str to swift-str:
let swiftStr = String (cString: pBuffer.assumingMemoryBound(to: Int8.self));
print("pBuffer content: \(bufferAsString)");
// to modify cpp-str without converting:
let swiftstr:String = "SwiftStr"
_ = swiftstr.withCString { (cString: UnsafePointer<Int8>) in
pBuffer.initializeMemory(as: Int8.self, from: cString, count: swiftstr.count+1)
}
}
Approach 2:
The ‘String’ type returned from a swift function is received as ‘swift::String’ type in cpp. This is implicitly casted to std::string type. The std::string has the method available to convert it to char *.
void
TWCppClass::StringConversion ()
{
// GetSwiftString() is a swift call that returns swift::String which can be received in std::string type
std::string stdstr = Module1::SwiftClass::GetSwiftString ();
char * cstr = stdstr.data ();
const char * conststr= stdstr.c_str ();
}
Approach 3:
The swift::String type that is obtained from a swift function can be received in char * by directly casting the address of the swift::String. We cannot directly receive a swift::String into a char *.
void
TWCppClass::StringConversion ()
{
// GetSwiftString() is a swift call that returns swift::String
swift::String swiftstr = Module1::SwiftClass::GetSwiftString ();
// obtaining the address of swift string and casting it into char *
char * cstr = (char*)&swiftstr;
}
I'm developing an audio unit for use on iOS. The AUv3 worked fine with xcode 15.X and swift 5.X. I recently tried to submit an update to my plug-in but Apple refused submission because my Xcode was not the latest. Now that I'm on Xcode 16.4 I can't get my project to compile, even when following all of the same previous steps.
As one example of a change, Xcode doesn't appear to include the “C++ and Objective-C interoperability” build setting that it used to. This setting is noted in the Swift documentation and I used to need it, https://www.swift.org/documentation/cxx-interop/project-build-setup/#mixing-swift-and-c-using-xcode
Currently my C++ code can't see anything from Swift, and I get a "Use of undeclared identifier 'project_name'". I've selected Switch support for version 5.0 in an attempt to minimize changes from Apple.
My process is I generate an Xcode project file from my audio plugin support, JUCE. Then I add in the swift files, click yes to create bridging headers, but c++ doesn't see swift anymore. I'd greatly appreciate any suggestions.
Topic:
Programming Languages
SubTopic:
Swift
Greetings,
func stepForward(_ input: Int) -> Int {
return input + 1
}
func stepBackward(_ input: Int) -> Int {
return input - 1
}
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
return backward ? stepBackward : stepForward /* Error
type of expression is ambiguous without a type annotation */
}
Why am I getting this error. If I change the function to
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
if backward {
return stepBackward
else {
return stepForward
}
}
Why is the previous chooseStepFunction giving me an error ?
Thx in advance
I filed the following issue on swiftlang/swift on GitHub (Aug 8th), and a followup the swift.org forums, but not getting any replies. As we near the release of Swift 6.2, I want to know if what I'm seeing below is expected, or if it's another case where the compiler needs a fix.
protocol P1: Equatable { }
struct S1: P1 { }
// Error: Conformance of 'S1' to protocol 'P1' crosses into main actor-isolated code an can cause data races
struct S1Workaround: @MainActor P1 { } // OK
// Another potential workaround if `Equatable` conformance can be moved to the conforming type.
protocol P2 { }
struct S2: Equatable, P2 { } // OK
There was a prior compiler bug fix which addressed inhereted protocols regarding @MainActor. For Equatable, one still has to use @MainActoreven when the default actor isolation is MainActor.
Also affects Hashable and any other protocol inheriting from Equatable.
hi,
Is it possible to compare two vectors and get a boolean answer?
example :
uint642_t a;
uint642_t b;
.../...
if(a == b)
.../...
how to do it ?
thank
I would like to avoid the middle man and call Objective C directly from C
Currently I do this
This is called from a dispatch table in a pure C file
_ctx->mt_render_funcs.mtlEnd(_ctx);
Which calls this routine in a obj c file .m
void mtlEnd(MTRenderContext mt_ctx)
{
// Call the Objective-C method using Objective-C syntax
[(__bridge id) mt_ctx->mt_render_funcs.mtlObj mtlEnd];
}
Which ends up here... in ObjC
#pragma mark mtlEnd
(void)mtlEnd
{
// vertex buffer
size_t size;
size = sizeof(Vertex4ColorNormalTex) * _ctx->vert_eng.current_vertex;
[_currentRenderEncoder setVertexBytes:_ctx->vert_eng.vertices length: size atIndex: VertexInputIndexVertices];
[_currentRenderEncoder drawPrimitives:(MTLPrimitiveType)_ctx->vert_eng.prim_type
vertexStart:0
vertexCount:_ctx->vert_eng.current_vertex];
}
It would simplify this to get rid of one call and call ObjC directly.
The other idea is I want to use GCD and put a lock / unlock on the call from C to ensure thread safety so I can use GCD to dispatch a thread to do the ObjC routines.
I want to stick with C as the foundation so it can be used directly from C or a FFI interface from other languages. But Metal works well in ObjC and I would prefer to use that.
Thanks ahead of time.
Consider this simple miniature of my iOS Share Extension:
import SwiftUI
import Photos
class ShareViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
if let itemProviders = (extensionContext?.inputItems.first as? NSExtensionItem)?.attachments {
let hostingView = UIHostingController(rootView: ShareView(extensionContext: extensionContext, itemProviders: itemProviders))
hostingView.view.frame = view.frame
view.addSubview(hostingView.view)
}
}
}
struct ShareView: View {
var extensionContext: NSExtensionContext?
var itemProviders: [NSItemProvider]
var body: some View {
VStack{}
.task{
await extractItems()
}
}
func extractItems() async {
guard let itemProvider = itemProviders.first else { return }
guard itemProvider.hasItemConformingToTypeIdentifier(UTType.url.identifier) else { return }
do {
guard let url = try await itemProvider.loadItem(forTypeIdentifier: UTType.url.identifier) as? URL else { return }
try await downloadAndSaveMedia(reelURL: url.absoluteString)
extensionContext?.completeRequest(returningItems: [])
}
catch {}
}
}
On the line 34
guard let url = try await itemProvider.loadItem
...
I get these warnings:
Passing argument of non-sendable type '[AnyHashable : Any]?' outside of main actor-isolated context may introduce data races; this is an error in the Swift 6 language mode
1.1. Generic enum 'Optional' does not conform to the 'Sendable' protocol (Swift.Optional)
Passing argument of non-sendable type 'NSItemProvider' outside of main actor-isolated context may introduce data races; this is an error in the Swift 6 language mode
2.2. Class 'NSItemProvider' does not conform to the 'Sendable' protocol (Foundation.NSItemProvider)
How to fix them in Xcode 16?
Please provide a solution which works, and not the one which might (meaning you run the same code in Xcode, add your solution and see no warnings).
I tried
Decorating everything with @MainActors
Using @MainActor in the .task
@preconcurrency import
Decorating everything with @preconcurrency
Playing around with nonisolated
I'm trying to use FormatStyle from Foundation to format numbers when printing a vector structure. See code below.
import Foundation
struct Vector<T> {
var values: [T]
subscript(item: Int) -> T {
get { values[item] }
set { values[item] = newValue }
}
}
extension Vector: CustomStringConvertible {
var description: String {
var desc = "( "
desc += values.map { "\($0)" }.joined(separator: " ")
desc += " )"
return desc
}
}
extension Vector {
func formatted<F: FormatStyle>(_ style: F) -> String where F.FormatInput == T, F.FormatOutput == String {
var desc = "( "
desc += values.map { style.format($0) }.joined(separator: " ")
desc += " )"
return desc
}
}
In the example below, the vector contains a mix of integer and float literals. The result is a vector with a type of Vector<Double>. Since the values of the vector are inferred as Double then I expect the print output to display as decimal numbers. However, the .number formatted output seems to ignore the vector type and print the values as a mix of integers and decimals. This is fixed by explicitly providing a format style with a fraction length. So why is the .formatted(.number) method ignoring the vector type T which is Double in this example?
let vec = Vector(values: [-2, 5.5, 100, 19, 4, 8.37])
print(vec)
print(vec.formatted(.number))
print(vec.formatted(.number.precision(.fractionLength(1...))))
( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types
( -2 5.5 100 19 4 8.37 ) // wrong output that uses Int and Double types
( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types
Hello, I was hoping to clarify my understanding of the use of for await with an AsyncStream. My use case is, I'd like to yield async closures to the stream's continuation, with the idea that, when I use for await with the stream to process and execute the closures, it would only continue on to the following closure once the current closure has been run to completion.
At a high level, I am trying to implement in-order execution of async closures in the context of re-entrancy. An example of asynchronous work I want to execute is a network call that should write to a database:
func syncWithRemote() async -> Void {
let data = await fetchDataFromNetwork()
await writeToLocalDatabase(data)
}
For the sake of example, I'll call the intended manager of closure submission SingleOperationRunner.
where, at a use site such as this, my desired outcome is that call 1 of syncWithRemote() is always completed before call 2 of it:
let singleOperationRunner = SingleOperationRunner(priority: nil)
singleOperationRunner.run {
syncWithRemote()
}
singleOperationRunner.run {
syncWithRemote()
}
My sketch implementation looks like this:
public final class SingleOperationRunner {
private let continuation: AsyncStream<() async -> Void>.Continuation
public init(priority: TaskPriority?) {
let (stream, continuation) = AsyncStream.makeStream(of: (() async -> Void).self)
self.continuation = continuation
Task.detached(priority: priority) {
// Will this loop only continue when the `await operation()` completes?
for await operation in stream {
await operation()
}
}
}
public func run(operation: @escaping () async -> Void) {
continuation.yield(operation)
}
deinit {
continuation.finish()
}
}
The resources I've found are https://developer.apple.com/videos/play/wwdc2022-110351/?time=1445 and https://forums.swift.org/t/swift-async-func-to-run-sequentially/60939/2 but do not think I have fully put the pieces together, so would appreciate any help!
I am writing a SPM based project for MacOS. In this project? I need to access MacOS Keychain.
I am write a swift test built by SPM testTarget(). I can see it generates a bundle ./.build/x86_64-apple-macosx/debug/MyProjectTests.xctest with an executable:
% file ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests
./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests: Mach-O 64-bit bundle x86_64
This bundle file cannot be executed. How can I execute its tests?
I tried with xcodebuild test-without-building -xctestrun ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest -destination 'platform=macOS' without any chance.
Obviously the next question is can I 'simply' add entitlement to this bundle with codesign to fix my enttilement error.
My error when running the test is A required entitlement isn't present.
Hello,
I have a json array showing in Xcode debugger (from the line "print(dataString)"):
Optional("[{\"id\":\"8e8tfdcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w\",\"name\":\"Ameliana\",\"country\":\"France\",\"type\":\"Private\\/Corporate\",\"overallrecsit\":\"Positive\",\"dlastupd\":\"1741351633\",\"doverallrecsit\":\"1546848000\"},{\"id\":\"z69718a1a5z2y5czkwrhr1u37h7h768v05qr3pf1fegh4r4yrt5a68\",\"name\":\"Timberland\",\"country\":\"Switzerland\",\"type\":\"Charter\",\"overallrecsit\":\"Negative\",\"dlastupd\":\"1741351615\",\"doverallrecsit\":\"1740434582\"},
But my JSON decoder is throwing the catch error "Error in JSON parsing"
This is the code:
super.viewDidLoad()
let urlString = "https://www.pilotjobsnetwork.com/service_ios.php"
let url = URL(string: urlString)
guard url != nil else {
return
}
let session = URLSession.shared
let dataTask = session.dataTask(with: url!) { (data, response, error) in
var dataString = String(data: data!, encoding: String.Encoding.utf8)
print(dataString)
if error == nil && data != nil {
// Parse JSON
let decoder = JSONDecoder()
do {
let newsFeed = try decoder.decode(NewsFeed.self, from: data!)
print(newsFeed)
print(error)
}
catch{
print("Error in JSON parsing")
}
}
}
// Make the API Call
dataTask.resume()
}
And this is my Codable file NewsFeed.swift:
struct NewsFeed: Codable {
var id: String
var name: String
var country: String
var type: String
var overallrecsit: String
var dlastupd: String
var doverallrecsit: String
}
Please do you know why the parsing may be failing? Is it significant that in the debugging window the JSON is displaying backslashes before the quotation marks?
Thank you for any pointers :-)