Why am I seeing a compilation error about -falign-loops using LLVM?

Question

I have an iOS application that uses Core Plot, and after I upgraded to Xcode 4.5, I'm seeing the following error when building:

clang: error: argument unused during compilation:
'-falign-loops=16' Command
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/u‌​sr/bin/clang
failed with exit code 1

What can cause this and how can I fix it?

Answer 1

-falign-loops is a GCC option not used by clang. It is normally a warning in clang, so I assume you have the compiler option set to treat warnings as errors ( -Werror ).

Answer 2

I had the same issue using CorePlot, the following solved the problem

• Go to CorePlot-CocoaTouch Project
• Build Settings
• Scroll down to Build Options
• Compiler for C/C++/Objective-C set its value to LLVM GCC 4.2

Hope it resolves your issue