I am using ARC successfully in my project. However, I have encountered a few files (e.g., in unit tests and mock objects) where the rules of ARC are a little more fragile right now. I recall hearing that there was a way to disable ARC on a per-file basis, though I have been unable to find this option.
Is this possible? How do I disable ARC on a per-file basis?
It is possible to disable ARC for individual files by adding the
-fno-objc-arc
compiler flag for those files.You add compiler flags in Targets -> Build Phases -> Compile Sources. You have to double click on the right column of the row under Compiler Flags. You can also add it to multiple files by holding the cmd button to select the files and then pressing enter to bring up the flag edit box. (Note that editing multiple files will overwrite any flags that it may already have.)
I created a sample project that has an example: https://github.com/jaminguy/NoArc
See this answer for more info: Disable Automatic Reference Counting for Some Files
For Xcode 4.3 the easier way might be: Edit/Refactor/Convert to objective-C ARC, then check off the files you don't want to be converted. I find this way the same as using the compiler flag above.
I think all the other answers are explaining how to disable MRC(Manual Reference Count) and enabling ARC(Automatic Reference Count). To Use MRC(Manual Reference Count) i.e. Disabling ARC(Automatic Reference Count) on MULTIPLE files:
Following Step to to enable disable ARC
Select Xcode project Go to targets Select the Build phases section Inside the build phases section select the compile sources. Select the file which you do not want to disable ARC and add -fno-objc-arc
use -fno-objc-arc for each file in build phases
Please Just follow the screenshot and enter -fno-objc-arc .