From 81ca8ebee229ec85d9d2c54d7eda7fd0106a34f3 Mon Sep 17 00:00:00 2001 From: Eduard-Mihai Burtescu Date: Fri, 28 Sep 2018 22:54:18 +0300 Subject: [PATCH] rustc_typeck: don't lint non-extern-prelude extern crate's in Rust 2018. --- src/librustc_typeck/check_unused.rs | 16 +++-- .../ui-fulldeps/unnecessary-extern-crate.rs | 22 ++----- .../unnecessary-extern-crate.stderr | 64 ++----------------- .../ui/rust-2018/remove-extern-crate.fixed | 6 ++ src/test/ui/rust-2018/remove-extern-crate.rs | 6 ++ .../ui/rust-2018/remove-extern-crate.stderr | 8 +-- 6 files changed, 34 insertions(+), 88 deletions(-) diff --git a/src/librustc_typeck/check_unused.rs b/src/librustc_typeck/check_unused.rs index 5967bd1ba3e..4b3f08a10ff 100644 --- a/src/librustc_typeck/check_unused.rs +++ b/src/librustc_typeck/check_unused.rs @@ -130,15 +130,13 @@ fn unused_crates_lint<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) { }); for extern_crate in &crates_to_lint { - assert!(extern_crate.def_id.is_local()); + let id = tcx.hir.as_local_node_id(extern_crate.def_id).unwrap(); + let item = tcx.hir.expect_item(id); // If the crate is fully unused, we suggest removing it altogether. // We do this in any edition. if extern_crate.warn_if_unused { if let Some(&span) = unused_extern_crates.get(&extern_crate.def_id) { - assert_eq!(extern_crate.def_id.krate, LOCAL_CRATE); - let hir_id = tcx.hir.definitions().def_index_to_hir_id(extern_crate.def_id.index); - let id = tcx.hir.hir_to_node_id(hir_id); let msg = "unused extern crate"; tcx.struct_span_lint_node(lint, id, span, msg) .span_suggestion_short_with_applicability( @@ -157,6 +155,13 @@ fn unused_crates_lint<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) { continue; } + // If the extern crate isn't in the extern prelude, + // there is no way it can be written as an `use`. + let orig_name = extern_crate.orig_name.unwrap_or(item.name); + if !tcx.sess.extern_prelude.contains(&orig_name) { + continue; + } + // If the extern crate has any attributes, they may have funky // semantics we can't faithfully represent using `use` (most // notably `#[macro_use]`). Ignore it. @@ -165,9 +170,6 @@ fn unused_crates_lint<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) { } // Otherwise, we can convert it into a `use` of some kind. - let hir_id = tcx.hir.definitions().def_index_to_hir_id(extern_crate.def_id.index); - let id = tcx.hir.hir_to_node_id(hir_id); - let item = tcx.hir.expect_item(id); let msg = "`extern crate` is not idiomatic in the new edition"; let help = format!( "convert it to a `{}`", diff --git a/src/test/ui-fulldeps/unnecessary-extern-crate.rs b/src/test/ui-fulldeps/unnecessary-extern-crate.rs index df723ddf590..1cdc9229d07 100644 --- a/src/test/ui-fulldeps/unnecessary-extern-crate.rs +++ b/src/test/ui-fulldeps/unnecessary-extern-crate.rs @@ -20,33 +20,23 @@ extern crate alloc as x; //~^ ERROR unused extern crate //~| HELP remove +extern crate proc_macro; + #[macro_use] extern crate test; pub extern crate test as y; -//~^ ERROR `extern crate` is not idiomatic in the new edition -//~| HELP convert it to a `pub use` pub extern crate libc; -//~^ ERROR `extern crate` is not idiomatic in the new edition -//~| HELP convert it to a `pub use` pub(crate) extern crate libc as a; -//~^ ERROR `extern crate` is not idiomatic in the new edition -//~| HELP convert it to a `pub(crate) use` crate extern crate libc as b; -//~^ ERROR `extern crate` is not idiomatic in the new edition -//~| HELP convert it to a `crate use` mod foo { pub(in crate::foo) extern crate libc as c; - //~^ ERROR `extern crate` is not idiomatic in the new edition - //~| HELP convert it to a `pub(in crate::foo) use` pub(super) extern crate libc as d; - //~^ ERROR `extern crate` is not idiomatic in the new edition - //~| HELP convert it to a `pub(super) use` extern crate alloc; //~^ ERROR unused extern crate @@ -57,12 +47,8 @@ mod foo { //~| HELP remove pub extern crate test; - //~^ ERROR `extern crate` is not idiomatic in the new edition - //~| HELP convert it pub extern crate test as y; - //~^ ERROR `extern crate` is not idiomatic in the new edition - //~| HELP convert it mod bar { extern crate alloc; @@ -74,8 +60,6 @@ mod foo { //~| HELP remove pub(in crate::foo::bar) extern crate libc as e; - //~^ ERROR `extern crate` is not idiomatic in the new edition - //~| HELP convert it to a `pub(in crate::foo::bar) use` fn dummy() { unsafe { @@ -96,4 +80,6 @@ mod foo { fn main() { unsafe { a::getpid(); } unsafe { b::getpid(); } + + proc_macro::TokenStream::new(); } diff --git a/src/test/ui-fulldeps/unnecessary-extern-crate.stderr b/src/test/ui-fulldeps/unnecessary-extern-crate.stderr index a4307112157..58ec5901585 100644 --- a/src/test/ui-fulldeps/unnecessary-extern-crate.stderr +++ b/src/test/ui-fulldeps/unnecessary-extern-crate.stderr @@ -16,83 +16,29 @@ error: unused extern crate LL | extern crate alloc as x; | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:26:1 - | -LL | pub extern crate test as y; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:30:1 - | -LL | pub extern crate libc; - | ^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:34:1 - | -LL | pub(crate) extern crate libc as a; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub(crate) use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:38:1 - | -LL | crate extern crate libc as b; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `crate use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:43:5 - | -LL | pub(in crate::foo) extern crate libc as c; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub(in crate::foo) use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:47:5 - | -LL | pub(super) extern crate libc as d; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub(super) use` - error: unused extern crate - --> $DIR/unnecessary-extern-crate.rs:51:5 + --> $DIR/unnecessary-extern-crate.rs:41:5 | LL | extern crate alloc; | ^^^^^^^^^^^^^^^^^^^ help: remove it error: unused extern crate - --> $DIR/unnecessary-extern-crate.rs:55:5 + --> $DIR/unnecessary-extern-crate.rs:45:5 | LL | extern crate alloc as x; | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:59:5 - | -LL | pub extern crate test; - | ^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub use` - -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:63:5 - | -LL | pub extern crate test as y; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub use` - error: unused extern crate - --> $DIR/unnecessary-extern-crate.rs:68:9 + --> $DIR/unnecessary-extern-crate.rs:54:9 | LL | extern crate alloc; | ^^^^^^^^^^^^^^^^^^^ help: remove it error: unused extern crate - --> $DIR/unnecessary-extern-crate.rs:72:9 + --> $DIR/unnecessary-extern-crate.rs:58:9 | LL | extern crate alloc as x; | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it -error: `extern crate` is not idiomatic in the new edition - --> $DIR/unnecessary-extern-crate.rs:76:9 - | -LL | pub(in crate::foo::bar) extern crate libc as e; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `pub(in crate::foo::bar) use` - -error: aborting due to 15 previous errors +error: aborting due to 6 previous errors diff --git a/src/test/ui/rust-2018/remove-extern-crate.fixed b/src/test/ui/rust-2018/remove-extern-crate.fixed index cdae815b200..34c7266b637 100644 --- a/src/test/ui/rust-2018/remove-extern-crate.fixed +++ b/src/test/ui/rust-2018/remove-extern-crate.fixed @@ -14,6 +14,7 @@ // aux-build:remove-extern-crate.rs // compile-flags:--extern remove_extern_crate +#![feature(alloc)] #![warn(rust_2018_idioms)] @@ -22,11 +23,16 @@ use remove_extern_crate; #[macro_use] extern crate remove_extern_crate as something_else; +// Shouldn't suggest changing to `use`, as the `alloc` +// crate is not in the extern prelude - see #54381. +extern crate alloc; + fn main() { another_name::mem::drop(3); another::foo(); remove_extern_crate::foo!(); bar!(); + alloc::vec![5]; } mod another { diff --git a/src/test/ui/rust-2018/remove-extern-crate.rs b/src/test/ui/rust-2018/remove-extern-crate.rs index 4984da802c0..570bbb02f72 100644 --- a/src/test/ui/rust-2018/remove-extern-crate.rs +++ b/src/test/ui/rust-2018/remove-extern-crate.rs @@ -14,6 +14,7 @@ // aux-build:remove-extern-crate.rs // compile-flags:--extern remove_extern_crate +#![feature(alloc)] #![warn(rust_2018_idioms)] extern crate core; @@ -22,11 +23,16 @@ use remove_extern_crate; #[macro_use] extern crate remove_extern_crate as something_else; +// Shouldn't suggest changing to `use`, as the `alloc` +// crate is not in the extern prelude - see #54381. +extern crate alloc; + fn main() { another_name::mem::drop(3); another::foo(); remove_extern_crate::foo!(); bar!(); + alloc::vec![5]; } mod another { diff --git a/src/test/ui/rust-2018/remove-extern-crate.stderr b/src/test/ui/rust-2018/remove-extern-crate.stderr index 064a853625f..847ba5f3544 100644 --- a/src/test/ui/rust-2018/remove-extern-crate.stderr +++ b/src/test/ui/rust-2018/remove-extern-crate.stderr @@ -1,24 +1,24 @@ warning: unused extern crate - --> $DIR/remove-extern-crate.rs:19:1 + --> $DIR/remove-extern-crate.rs:20:1 | LL | extern crate core; | ^^^^^^^^^^^^^^^^^^ help: remove it | note: lint level defined here - --> $DIR/remove-extern-crate.rs:17:9 + --> $DIR/remove-extern-crate.rs:18:9 | LL | #![warn(rust_2018_idioms)] | ^^^^^^^^^^^^^^^^ = note: #[warn(unused_extern_crates)] implied by #[warn(rust_2018_idioms)] warning: `extern crate` is not idiomatic in the new edition - --> $DIR/remove-extern-crate.rs:20:1 + --> $DIR/remove-extern-crate.rs:21:1 | LL | extern crate core as another_name; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert it to a `use` warning: `extern crate` is not idiomatic in the new edition - --> $DIR/remove-extern-crate.rs:33:5 + --> $DIR/remove-extern-crate.rs:39:5 | LL | extern crate core; | ^^^^^^^^^^^^^^^^^^ help: convert it to a `use`