Will rustc enable frame pointers on linux by default?

Question

The rustc book indicates that

The default behaviour, if frame pointers are not force-enabled, depends on the target

What is the default behavior on linux, and how can I find the default value for all targets?

Answer 1

Having a look through the rustc-code, it looks as linux is defaulted to FramePointer::MayOmit

Allows the machine code generator to omit the frame pointers. This option does not guarantee that the frame pointers will be omitted.

This corresponds to llvm's frame-pointer function attribute with a value of none. So it leaves it up to llvm to decide on a per-function basis.

You can see all the platform defaults in rust/src/librustc_target/spec/.