Mogenerator and ARC in XCode 4.6

Question

I am just getting started with integrating mogenerator into an app project with Core Data, per recommendations as a best practice. I added the following build script, with a flag to support ARC.

mogenerator -m FavesDataModel.xcdatamodeld/FavesDataModel.xcdatamodel --template-var arc=true

The script successfully builds all the necessary classes and subclasses. At that time, I copied all the generated files into my project. Initially, I got a clean successful build. However, when trying another build (without making any changes), it fails with the following ARC error:

ARC forbids Objective-C objects in structs or unions

The errors occur in the files generated with an underscore. Interestingly, when the build script builds the files as follows:

extern const struct FavoriteAttributes {
    __unsafe_unretained NSString *maxCFS;
    __unsafe_unretained NSString *maxFeet;
    __unsafe_unretained NSString *minCFS;
    __unsafe_unretained NSString *minFeet;
    __unsafe_unretained NSString *stationIdentifier;
    __unsafe_unretained NSString *stationRealName;
    __unsafe_unretained NSString *stationState;
} FavoriteAttributes;

However, after a successful build, XCode removes the __unsafe_unretained attribute.

Are there known issues with using mogenerator with ARC turned on? Any ideas of a solution or workaround? Thanks! V

__unsafe_unretained should not be removed in the generated file, that sounds strange ... — Martin R
The template var is correct in resolving the ARC issue. Are you sure Xcode is using the correct generated class files? Your mogenerator command will put them in the project root. — David Snabel-Caunt

Pheepster Pheepster · Accepted Answer · 2013-08-12T17:42:54

Try removing --template-var arc=true from your build script.

Then in XCode, Project Properties, Compile sources, set the problem files to have the following flag

fno-objc-arc

This will turn off ARC for only those files.

Mogenerator and ARC in XCode 4.6

1 Answers