Avoid loading needless proc-macro dependencies #38024
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jseyfried
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Could this be reviewed and prioritised? This is blocking rustup in Servo. |
| @@ -67,6 +67,8 @@ pub struct CrateSource { | |||
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| #[derive(RustcEncodable, RustcDecodable, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Debug)] | |||
| pub enum DepKind { | |||
| /// A dependency that is only used for its macros, none of which are visible from other crates. | |||
| UnexportedMacrosOnly, | |||
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Are these only used by monomorphised functions or is there some reason to include them. Would be good to comment in any case.
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UnexportedMacrosOnly are only included in the metadata as placeholders (the CrateNum of a dependency is computed from its position in the dependency list) -- I'll add a comment.
Does that answer your question? (not sure how monomorphised functions are relevant)
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Oh, I see -- monomorphised functions from extern crates might need to access non-visible functions. I don't think this is relevant to macros though, since expansion finishes before monomorphization.
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@bors r=nrc |
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📌 Commit 1fd9041 has been approved by |
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Avoid loading needless proc-macro dependencies Fixes #37958 when no proc-macros are exported; in particular, without `pub extern crate proc_macros;`, `#![feature(macro_reexport)]`, or `#![feature(use_extern_macros)]`. I opened rust-lang/cargo#3334 for exported proc macros. r? @alexcrichton
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⛄ The build was interrupted to prioritize another pull request. |
Fixes #37958 when no proc-macros are exported; in particular, without
pub extern crate proc_macros;,#![feature(macro_reexport)], or#![feature(use_extern_macros)].I opened rust-lang/cargo#3334 for exported proc macros.
r? @alexcrichton