Xcode中NATIVE_ARCH与NATIVE_ARCH_ACTUAL的区别及取值疑问

Let me break down these two Xcode build variables clearly, since the official docs can be a bit ambiguous:

What do they actually mean? #

• NATIVE_ARCH: This is tied to the target platform/SDK you're building for, not your physical Mac. Think of it as the "base architecture context" Xcode uses for compiling your code. If you're targeting an older iOS device (like armv7), even on an Intel x86_64 Mac, NATIVE_ARCH will report armv7—because Xcode is emulating the compile environment of that target platform.
• NATIVE_ARCH_ACTUAL: This is the real hardware architecture of your Mac. It never lies: if you're on an Intel machine, it'll show x86_64; on an M-series chip, arm64. This value ignores your build target and only reflects the physical device running Xcode.

Why are you seeing NATIVE_ARCH = armv7 on an x86_64 Mac? #

That's totally expected when you're targeting an iOS platform that includes armv7 in its supported architectures. Even if you set your project's architecture to arm64, some legacy SDK settings or fallback logic might still have Xcode using armv7 as the base context for NATIVE_ARCH (especially if you haven't explicitly excluded armv7 from your build settings).

Which value should you trust? #

• Trust NATIVE_ARCH_ACTUAL if you need to know the real hardware architecture of your Mac—this is the one that reflects what your physical machine is running.
• Trust NATIVE_ARCH if you need to know the current build's target architecture context—this tells you what platform Xcode is compiling for at that moment.

内容的提问来源于stack exchange，提问作者gil_mo