From d1e337bded30b84df777f6de3d8fc588286f0834 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Wed, 24 Oct 2018 01:03:47 +0300
Subject: [PATCH] Prohibit macro-expanded `extern crate` items shadowing crates
passed with `--extern`
---
src/librustc_resolve/build_reduced_graph.rs | 17 +++++++++++++++--
.../feature-gate-extern_crate_item_prelude.rs | 7 +++++++
...eature-gate-extern_crate_item_prelude.stderr | 10 +++++++++-
.../imports/extern-prelude-extern-crate-fail.rs | 9 +++++++++
.../extern-prelude-extern-crate-fail.stderr | 13 +++++++++++--
5 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index 777a5ab79d090..aa7bfeae5f48b 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -446,10 +446,23 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
let binding =
(module, ty::Visibility::Public, sp, expansion).to_name_binding(self.arenas);
if ptr::eq(self.current_module, self.graph_root) {
- self.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
+ if let Some(entry) = self.extern_prelude.get(&ident.modern()) {
+ if expansion != Mark::root() && orig_name.is_some() &&
+ entry.extern_crate_item.is_none() {
+ self.session.span_err(item.span, "macro-expanded `extern crate` items \
+ cannot shadow names passed with \
+ `--extern`");
+ }
+ }
+ let entry = self.extern_prelude.entry(ident.modern())
+ .or_insert(ExternPreludeEntry {
extern_crate_item: None,
introduced_by_item: true,
- }).extern_crate_item = Some(binding);
+ });
+ entry.extern_crate_item = Some(binding);
+ if orig_name.is_some() {
+ entry.introduced_by_item = true;
+ }
}
let directive = self.arenas.alloc_import_directive(ImportDirective {
root_id: item.id,
diff --git a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
index eb7c52c3d0f32..a043b6c2e6107 100644
--- a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
+++ b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
@@ -36,4 +36,11 @@ mod import_absolute {
//~^ ERROR use of extern prelude names introduced with `extern crate` items is unstable
}
+extern crate alloc as core;
+
+mod unrelated_crate_renamed {
+ type A = core::boxed::Box<u8>;
+ //~^ ERROR use of extern prelude names introduced with `extern crate` items is unstable
+}
+
fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
index 4dec8a35bcab1..cabfb56d7a840 100644
--- a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
+++ b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
@@ -62,6 +62,14 @@ LL | type A = ::alloc::boxed::Box<u8>;
|
= help: add #![feature(extern_crate_item_prelude)] to the crate attributes to enable
-error: aborting due to 8 previous errors
+error[E0658]: use of extern prelude names introduced with `extern crate` items is unstable (see issue #54658)
+ --> $DIR/feature-gate-extern_crate_item_prelude.rs:42:14
+ |
+LL | type A = core::boxed::Box<u8>;
+ | ^^^^
+ |
+ = help: add #![feature(extern_crate_item_prelude)] to the crate attributes to enable
+
+error: aborting due to 9 previous errors
For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/imports/extern-prelude-extern-crate-fail.rs b/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
index 22248af6d3a2d..57b097c9df318 100644
--- a/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
+++ b/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
@@ -1,4 +1,5 @@
// aux-build:two_macros.rs
+// compile-flags:--extern non_existent
mod n {
extern crate two_macros;
@@ -10,4 +11,12 @@ mod m {
}
}
+macro_rules! define_std_as_non_existent {
+ () => {
+ extern crate std as non_existent;
+ //~^ ERROR `extern crate` items cannot shadow names passed with `--extern`
+ }
+}
+define_std_as_non_existent!();
+
fn main() {}
diff --git a/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr b/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
index 464812f1f6902..8f68d2af34ca3 100644
--- a/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
+++ b/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
@@ -1,9 +1,18 @@
+error: macro-expanded `extern crate` items cannot shadow names passed with `--extern`
+ --> $DIR/extern-prelude-extern-crate-fail.rs:16:9
+ |
+LL | extern crate std as non_existent;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL | define_std_as_non_existent!();
+ | ------------------------------ in this macro invocation
+
error[E0433]: failed to resolve. Use of undeclared type or module `two_macros`
- --> $DIR/extern-prelude-extern-crate-fail.rs:9:9
+ --> $DIR/extern-prelude-extern-crate-fail.rs:10:9
|
LL | two_macros::m!(); //~ ERROR failed to resolve. Use of undeclared type or module `two_macros`
| ^^^^^^^^^^ Use of undeclared type or module `two_macros`
-error: aborting due to previous error
+error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0433`.