I have a makefile that builds some C files and if I run it on an M1 mac the resulting library has the architecture arm64 which I thought it what is necessary for them to compile with an Xcode project for iOS. I discovered I can run the command otool -l libf2c.a | grep platform which should tell me what it was compiled for and in my case it returns platform1 which indicates macOS. Based on this, I think I need a value of platform2 for iOS.

The reason this is an issue is because in Xcode I get the error ld: building for iOS, but linking in object file built for macOS, file '/Users/e.../close.o' for architecture arm64.

Based on what I have been researching it seems iOS and macOS have the same architecture (arm64) but are a different 'platform'? But, I am not sure how the platform is determined. Is there some setting in my makefile I need to specify the platform? I am assuming that if I am able to get the platform to be iOS then Xcode will cooperate and be able to build the library I have generated.

CodePudding user response：

The preferred way to compile for iOS via command line would probably be to use the xcrun command. This will allow you to specify the correct SDK for the platform you actually want to run on. For example:

prompt$ xcrun --sdk iphoneos --toolchain iphoneos clang -c test.c -o test.o -arch arm64
prompt$ otool -v -l test.o | grep platform
 platform IOS

TL;DR: change your compiler invocation from plain clang to xcrun --sdk iphoneos --toolchain iphoneos clang.