Error building iOS for device in Release mode

MacOSX and iOS
1

Hey all. I’m getting an error when building my iOS project, but only in specific circumstances. Specifically, if I build in Debug or Release for the Simulator (running iOS 11), I have no problems. If I build in Debug mode for my iPhone SE (iOS 11), no problems. If I build in Release mode for my iPhone SE, I get the following build error:

Aligned allocation function of type 'void *(std::size_t, std::align_val_t)' is only available on iOS 11 or newer.
and
Aligned deallocation function of type 'void (void *, std::align_val_t) noexcept' is only available on iOS 11 or newer.

Coming from the following block in juce_Singleton.h:

    Type* getWithoutChecking()
    {
        if (instance == nullptr)
        {
            auto newObject = new Type(); // I think it's the `new` right here causing the problem
            instance = newObject;
        }

        return instance;
    }

I can get around the problem and successfully build in Release mode for my device if I set the iOS Deployment Target option in Projucer to 11.0 for my Release configuration, but I find it interesting that this is only happening when I try to build for my device, and not when I build for Simulator. Also, ideally, I would like to support more than iOS 11+.

What are my options here? Is this a bugfix in JUCE? Or a constraint on my end that I just have to deal with? Thanks!

Edit: For reference, I am building against JUCE master@06c3674.
Edit: More info, seems to be stemming from the ContentSharer here– https://github.com/WeAreROLI/JUCE/blob/master/modules/juce_gui_basics/filebrowser/juce_ContentSharer.h#L41

2

I get the same error over here when trying to build and test on my iPhone 6s here. it happens for these functions for me in JUCE 4.3.1:

#if JUCE_COMPILER_SUPPORTS_LAMBDAS
void AudioPluginFormat::createPluginInstanceAsync (const PluginDescription& description,
                                                   double initialSampleRate,
                                                   int initialBufferSize,
                                                   std::function<void (AudioPluginInstance*, const String&)> f)
{
    struct CallbackInvoker  : public AudioPluginFormat::InstantiationCompletionCallback
    {
        CallbackInvoker (std::function<void (AudioPluginInstance*, const String&)> inCompletion)
            : completion (inCompletion)
        {}

        void completionCallback (AudioPluginInstance* instance, const String& error) override
        {
            completion (instance, error);
        }

        std::function<void (AudioPluginInstance*, const String&)> completion;
    };

    createPluginInstanceAsync (description, initialSampleRate, initialBufferSize, new CallbackInvoker (f));
}
#endif

the new CallbackInvoker() is the culprit here ^

#if JUCE_COMPILER_SUPPORTS_LAMBDAS
void AudioPluginFormatManager::createPluginInstanceAsync (const PluginDescription& description,
                                                          double initialSampleRate,
                                                          int initialBufferSize,
                                                          std::function<void (AudioPluginInstance*, const String&)> f)
{
    String error;

    if (AudioPluginFormat* format = findFormatForDescription (description, error))
        return format->createPluginInstanceAsync (description, initialSampleRate, initialBufferSize, f);

    (new PluginFormatManagerHelpers::ErrorLambdaOnMessageThread (error, f))->post();
}
#endif

the new PluginFormatManagerHelpers is the culprit here ^

3

FWIW, Facebook also has this problem on iOS:

https://github.com/facebook/rocksdb/issues/4064

This problem is solved for me when I manually change the target to iOS 11 in Xcode. however, it makes me wonder how I’m supposed to target devices that don’t have iOS 11 installed yet.

4

Hmm. I’m struggling to reproduce this.

Could you please provide a project that shows this behaviour on JUCE’s develop branch?

5

I had to tell ProJucer to use C++17, LLVM libc++. the folks in #iphonedev on FreeNode said its because aligned allocation is a new thing in c++17, so it’s understandable that there is minimal hardware support, especially on iOS.

6

do you still need a project that does this?

7

Can’t you just pass -fno-aligned-allocation to the compiler if you want to support older hardware?

5 Likes
Aligned allocation function of type 'void *(std::size_t, std::align_val_t)' is only available on iOS 11 or newer
8

Sir, you are a WIZARD! Thank you! now I can support all the way back to iOS 9. awesome!