Re-export mlir_sys

[cospectrum]

Add pub use mlir_sys;, since mlir_sys types appear in the public api.
Inkwell re-exports llvm_sys for the same reason.
https://www.lurklurk.org/effective-rust/re-export.html

[raviqqe]

Cann't we use mlir_sys adding it as a dependency?

[cospectrum]

A user can depend on mlir_sys only if it has a semver compatible version that matches the version in melior toml, which is not always possible and which imposes a limitation on the user

[raviqqe]

Hmmm, but isn't the situation the same as pub use mlir_sys; because it's exposed from a melior crate?

[cospectrum]

mlir_sys exported from melior crate will have the version that melior has in its toml. 2 different mlir_sys

[raviqqe]

Why do you want to use the old version of mlir-sys?

[cospectrum]

Different reasons. Example of the problem: If a new semver version of mlir_sys comes out tomorrow, users start a project by running cargo add melior mlir_sys or they run cargo update, their project won't compile, and they come here to complain. Seen this in practice

[cospectrum]

Or if there is another crate in the project that depends on mlir_sys and publicly uses types, its version does not match melior, and the crate does not export its version of mlir_sys either. Then I simply cannot use melior and that crate at the same time.

[raviqqe]

If a new semver version of mlir_sys comes out tomorrow, users start a project by running cargo add melior mlir_sys or they run cargo update, their project won't compile, and they come here to complain. Seen this in practice

For this one, they can just specify a minor version like mlir-sys = "0.2" in their Cargo.toml.

Or if there is another crate in the project that depends on mlir_sys and publicly uses types, its version does not match melior, and the crate does not export its version of mlir_sys either. Then I simply cannot use melior and that crate at the same time.

For this one, they can use a package attribute for the second mlir-sys dependency. For example,

mlir-sys = "0.2"
mlir-sys1 = { version = "0.1", package = "mlir-sys" }

WDYT?

[cospectrum]

Solution for the first problem is correct, but may require some work if the project uses cargo update check in in ci.
Solution for the second problem may require a complex rewrite of the entire codebase. And grep + sed does not always work. I would simply prefer to use melior::mlir_sys from the beginning.

[cospectrum]

It's not difficult for melior, just 1 line in lib.rs 🥺