Why is rust calling GCC with an option it doesn't support? (Cross-compilation, linking to C++)

help
1

Hey! So I'm working on a C++ executable that statically links to a Rust library. When building for my development platform, it works fine. But when I build it for Nintendo Switch, it throws this error:

note: aarch64-none-elf-gcc: error: unrecognized command-line option '--script'

GCC doesn't seem to support "--script" specifically as an option. But when I looked at the Rust source code, it seems to pass "--script" regardless of the linker. (https://github.com/rust-lang/rust/blob/644e8068cbffef6428d1970fe50a4a863079ee54/compiler/rustc_codegen_ssa/src/back/link.rs#L1799)

I'm very hesitant to point fingers at Rust for this, because I'm not yet super fluent in Rust and I also expect this code has been thoroughly tested throughout the years. But honestly I'm just confused. Any help would be appreciated!

2

(Not knowledgeable about this topic specifically, just clicked around GitHub out of curiosity.)

Looks like Rust Switch support requires a linker script. (Or see the whole PR.) The assumption in the code you linked seems to be that "gnu flavored" linkers support --script.

Perhaps you can provide more details about your build invocation.

2 Likes
3

And it seems for the switch target we expect to directly call the linker rather than a linker wrapper like gcc or clang. By default we use the lld version shipped with rustc itself.

4

Alright so its specifically an issue with the switch target making that assumption?

5

Yeah, seems so.