ls

Option -Zls instructs the compiler to list all metadata from a given metadata file (i.e. files with the .rmeta extension).

This allows for debugging the metadata emitted by an earlier compilation.

Note that, while rustc usually works with .rs files, this option is meant purely for analyzing .rmeta files, and does not produce any compilation artifact.

Allowed values are:

• root: Crate info.
• lang_items: Language items used and missing, if any.
• features: Library features defined via the #[stable] and #[unstable] internal attributes.
• items: All items (such as modules, functions…) in the crate, including attributes like their visibility
• target_modifiers: Values of command-line arguments that rustc may require to match across linked crates.
• all: All of the above

Example

rustc +nightly -Zls=all target/debug/deps/libmy_crate-*.rmeta

This lists to stdout all metadata from the given .rmeta file