Objective-C ARC and Legacy Runtime compiling error

Question

I'm trying to compile sources with Xcode 4.6, for 32bit architecture, but getting this error:

error: -fobjc-arc is not supported on platforms using the legacy runtime
Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1

What's wrong?

score 14 · Accepted Answer · answered Mar 05 '13 at 02:10

14

You're mixing ARC (automatic reference counting) with the older Objective-C 1.0 runtime, which does not support ARC.

32-bit apps on OSX, automatically use the 1.0 Runtime, so you'll have to disable ARC for your project, and use Manual Reference Counting.

answered Mar 05 '13 at 02:10

Alan

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What if the message appears when compiling an iOS app? – Br.Bill Aug 07 '13 at 00:01
More than likely, you are targeting your iOS app to an older version of iOS which doesn't support ARC. – Alan Aug 07 '13 at 15:08
1

Also, Visual Source Safe is the devil. – Alan Aug 07 '13 at 15:08
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My OSX app is targeted for `64-bit Intel` and I'm still seeing this error. – zakdances Sep 27 '13 at 21:31
Is this still the case, that ARC is 64-bit only? – Tiago Sep 30 '16 at 16:02

score 2 · Answer 2 · answered Oct 10 '13 at 16:24

This problem recently resurfaced because Xcode 5 removes the ARCHS parameter - if you let it. But if you have a build server with Xcode 4 this defaults there to building 32 and 64 bit, which fails if you have ARC enabled.

See my writeup for a more detailed explanation.

Objective-C ARC and Legacy Runtime compiling error

2 Answers2

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