macOS: Why are Objective-C sections marked with `no_dead_strip`?

[madsmtm]

Why are the sections used internally by Objective-C marked by Clang with no_dead_strip?

For example __DATA,__objc_classrefs,regular,no_dead_strip in here.

It seems like that might prevent (like the name says) certain forms of dead stripping of Objective-C code? Though I couldn't find an example of this, in practice the linker seems to remove it anyhow?

[Berrysoft]

It seems that no_dead_strip for classes is added since the beginning: 33f66e6

That's 15 years ago:)

[Berrysoft]

The first no_dead_strip appeared in 2008: 8b8683f

The author is also on GitHub. I'm not sure whether it is appropriate to ask him directly:)

Seems that they decided to use no_dead_strip for objc ABI 2.

[llvmbot]

@llvm/issue-subscribers-clang-codegen

Author: Mads Marquart (madsmtm)

Why are the sections used internally by Objective-C marked by Clang with `no_dead_strip`?

For example __DATA,__objc_classrefs,regular,no_dead_strip in here.

It seems like that might prevent (like the name says) certain forms of dead stripping of Objective-C code? Though I couldn't find an example of this, in practice the linker seems to remove it anyhow?