diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 025f7fb5cc6c3..b8075ef2942e0 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -31,7 +31,7 @@
#![feature(slice_partition_dedup)]
#![feature(copy_within)]
#![feature(int_error_matching)]
-#![deny(rust_2018_idioms)]
+#![warn(rust_2018_idioms)]
extern crate test;
diff --git a/src/librustc_mir/borrow_check/error_reporting.rs b/src/librustc_mir/borrow_check/error_reporting.rs
index 1068305a1134c..1a1000f0bb41d 100644
--- a/src/librustc_mir/borrow_check/error_reporting.rs
+++ b/src/librustc_mir/borrow_check/error_reporting.rs
@@ -826,18 +826,21 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
let borrow_span = borrow_spans.var_or_use();
if let BorrowExplanation::MustBeValidFor {
- category: ConstraintCategory::Return,
+ category,
span,
ref opt_place_desc,
from_closure: false,
..
} = explanation {
- return self.report_cannot_return_reference_to_local(
+ if let Some(diag) = self.try_report_cannot_return_reference_to_local(
borrow,
borrow_span,
span,
+ category,
opt_place_desc.as_ref(),
- );
+ ) {
+ return diag;
+ }
}
let mut err = self.infcx.tcx.path_does_not_live_long_enough(
@@ -1015,17 +1018,20 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
);
if let BorrowExplanation::MustBeValidFor {
- category: ConstraintCategory::Return,
+ category,
span,
from_closure: false,
..
} = explanation {
- return self.report_cannot_return_reference_to_local(
+ if let Some(diag) = self.try_report_cannot_return_reference_to_local(
borrow,
proper_span,
span,
+ category,
None,
- );
+ ) {
+ return diag;
+ }
}
let tcx = self.infcx.tcx;
@@ -1064,15 +1070,22 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
err
}
- fn report_cannot_return_reference_to_local(
+ fn try_report_cannot_return_reference_to_local(
&self,
borrow: &BorrowData<'tcx>,
borrow_span: Span,
return_span: Span,
+ category: ConstraintCategory,
opt_place_desc: Option<&String>,
- ) -> DiagnosticBuilder<'cx> {
+ ) -> Option<DiagnosticBuilder<'cx>> {
let tcx = self.infcx.tcx;
+ let return_kind = match category {
+ ConstraintCategory::Return => "return",
+ ConstraintCategory::Yield => "yield",
+ _ => return None,
+ };
+
// FIXME use a better heuristic than Spans
let reference_desc = if return_span == self.mir.source_info(borrow.reserve_location).span {
"reference to"
@@ -1110,7 +1123,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
let local = if let Place::Base(PlaceBase::Local(local)) = *root_place {
local
} else {
- bug!("report_cannot_return_reference_to_local: not a local")
+ bug!("try_report_cannot_return_reference_to_local: not a local")
};
match self.mir.local_kind(local) {
LocalKind::ReturnPointer | LocalKind::Temp => {
@@ -1131,6 +1144,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
let mut err = tcx.cannot_return_reference_to_local(
return_span,
+ return_kind,
reference_desc,
&place_desc,
Origin::Mir,
@@ -1140,7 +1154,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
err.span_label(borrow_span, note);
}
- err
+ Some(err)
}
fn report_escaping_closure_capture(
diff --git a/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs b/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
index c64d4b4a531e0..35efc6195be39 100644
--- a/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
@@ -310,9 +310,13 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
opt_place_desc,
}
} else {
+ debug!("explain_why_borrow_contains_point: \
+ Could not generate a region name");
BorrowExplanation::Unexplained
}
} else {
+ debug!("explain_why_borrow_contains_point: \
+ Could not generate an error region vid");
BorrowExplanation::Unexplained
}
}
diff --git a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs
index 4e197867bfb3e..4ced31593b1ae 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs
@@ -34,6 +34,7 @@ crate enum RegionNameSource {
MatchedAdtAndSegment(Span),
AnonRegionFromUpvar(Span, String),
AnonRegionFromOutput(Span, String, String),
+ AnonRegionFromYieldTy(Span, String),
}
impl RegionName {
@@ -48,7 +49,8 @@ impl RegionName {
RegionNameSource::MatchedHirTy(..) |
RegionNameSource::MatchedAdtAndSegment(..) |
RegionNameSource::AnonRegionFromUpvar(..) |
- RegionNameSource::AnonRegionFromOutput(..) => false,
+ RegionNameSource::AnonRegionFromOutput(..) |
+ RegionNameSource::AnonRegionFromYieldTy(..) => false,
}
}
@@ -105,6 +107,12 @@ impl RegionName {
format!("return type{} is {}", mir_description, type_name),
);
},
+ RegionNameSource::AnonRegionFromYieldTy(span, type_name) => {
+ diag.span_label(
+ *span,
+ format!("yield type is {}", type_name),
+ );
+ }
RegionNameSource::Static => {},
}
}
@@ -170,6 +178,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
self.give_name_if_anonymous_region_appears_in_output(
infcx, mir, mir_def_id, fr, counter,
)
+ })
+ .or_else(|| {
+ self.give_name_if_anonymous_region_appears_in_yield_ty(
+ infcx, mir, mir_def_id, fr, counter,
+ )
});
debug!("give_region_a_name: gave name {:?}", value);
@@ -676,10 +689,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
"give_name_if_anonymous_region_appears_in_output: return_ty = {:?}",
return_ty
);
- if !infcx
- .tcx
- .any_free_region_meets(&return_ty, |r| r.to_region_vid() == fr)
- {
+ if !tcx.any_free_region_meets(&return_ty, |r| r.to_region_vid() == fr) {
return None;
}
@@ -724,6 +734,57 @@ impl<'tcx> RegionInferenceContext<'tcx> {
})
}
+ fn give_name_if_anonymous_region_appears_in_yield_ty(
+ &self,
+ infcx: &InferCtxt<'_, '_, 'tcx>,
+ mir: &Mir<'tcx>,
+ mir_def_id: DefId,
+ fr: RegionVid,
+ counter: &mut usize,
+ ) -> Option<RegionName> {
+ // Note: generators from `async fn` yield `()`, so we don't have to
+ // worry about them here.
+ let yield_ty = self.universal_regions.yield_ty?;
+ debug!(
+ "give_name_if_anonymous_region_appears_in_yield_ty: yield_ty = {:?}",
+ yield_ty,
+ );
+
+ let tcx = infcx.tcx;
+
+ if !tcx.any_free_region_meets(&yield_ty, |r| r.to_region_vid() == fr) {
+ return None;
+ }
+
+ let mut highlight = RegionHighlightMode::default();
+ highlight.highlighting_region_vid(fr, *counter);
+ let type_name = infcx.extract_type_name(&yield_ty, Some(highlight));
+
+ let mir_node_id = tcx.hir().as_local_node_id(mir_def_id).expect("non-local mir");
+
+ let yield_span = match tcx.hir().get(mir_node_id) {
+ hir::Node::Expr(hir::Expr {
+ node: hir::ExprKind::Closure(_, _, _, span, _),
+ ..
+ }) => (
+ tcx.sess.source_map().end_point(*span)
+ ),
+ _ => mir.span,
+ };
+
+ debug!(
+ "give_name_if_anonymous_region_appears_in_yield_ty: \
+ type_name = {:?}, yield_span = {:?}",
+ yield_span,
+ type_name,
+ );
+
+ Some(RegionName {
+ name: self.synthesize_region_name(counter),
+ source: RegionNameSource::AnonRegionFromYieldTy(yield_span, type_name),
+ })
+ }
+
/// Creates a synthetic region named `'1`, incrementing the
/// counter.
fn synthesize_region_name(&self, counter: &mut usize) -> InternedString {
diff --git a/src/librustc_mir/util/borrowck_errors.rs b/src/librustc_mir/util/borrowck_errors.rs
index 4563c9f18a3e4..a5dfb736b819c 100644
--- a/src/librustc_mir/util/borrowck_errors.rs
+++ b/src/librustc_mir/util/borrowck_errors.rs
@@ -634,6 +634,7 @@ pub trait BorrowckErrors<'cx>: Sized + Copy {
fn cannot_return_reference_to_local(
self,
span: Span,
+ return_kind: &str,
reference_desc: &str,
path_desc: &str,
o: Origin,
@@ -642,7 +643,8 @@ pub trait BorrowckErrors<'cx>: Sized + Copy {
self,
span,
E0515,
- "cannot return {REFERENCE} {LOCAL}{OGN}",
+ "cannot {RETURN} {REFERENCE} {LOCAL}{OGN}",
+ RETURN=return_kind,
REFERENCE=reference_desc,
LOCAL=path_desc,
OGN = o
@@ -650,7 +652,7 @@ pub trait BorrowckErrors<'cx>: Sized + Copy {
err.span_label(
span,
- format!("returns a {} data owned by the current function", reference_desc),
+ format!("{}s a {} data owned by the current function", return_kind, reference_desc),
);
self.cancel_if_wrong_origin(err, o)
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index ffba9403743a3..6527e8655b5ef 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -1404,7 +1404,13 @@ pub fn checked_type_of<'a, 'tcx>(
if !fail {
return None;
}
- bug!("unexpected const parent path def {:?}", x);
+ tcx.sess.delay_span_bug(
+ DUMMY_SP,
+ &format!(
+ "unexpected const parent path def {:?}", x
+ ),
+ );
+ tcx.types.err
}
}
}
@@ -1412,7 +1418,13 @@ pub fn checked_type_of<'a, 'tcx>(
if !fail {
return None;
}
- bug!("unexpected const parent path {:?}", x);
+ tcx.sess.delay_span_bug(
+ DUMMY_SP,
+ &format!(
+ "unexpected const parent path {:?}", x
+ ),
+ );
+ tcx.types.err
}
}
}
@@ -1421,7 +1433,13 @@ pub fn checked_type_of<'a, 'tcx>(
if !fail {
return None;
}
- bug!("unexpected const parent in type_of_def_id(): {:?}", x);
+ tcx.sess.delay_span_bug(
+ DUMMY_SP,
+ &format!(
+ "unexpected const parent in type_of_def_id(): {:?}", x
+ ),
+ );
+ tcx.types.err
}
}
}
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index a49926158de1d..8a066f3f4a093 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -563,6 +563,7 @@ declare_features! (
// unanticipated results, such as compiler crashes. We warn the user about these
// to alert them.
const INCOMPLETE_FEATURES: &[Symbol] = &[
+ sym::impl_trait_in_bindings,
sym::generic_associated_types,
sym::const_generics
];
diff --git a/src/libsyntax_ext/proc_macro_decls.rs b/src/libsyntax_ext/proc_macro_decls.rs
index 5ced1400acb0e..1eab739cf6470 100644
--- a/src/libsyntax_ext/proc_macro_decls.rs
+++ b/src/libsyntax_ext/proc_macro_decls.rs
@@ -328,6 +328,7 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
// Creates a new module which looks like:
//
+// #[doc(hidden)]
// mod $gensym {
// extern crate proc_macro;
//
@@ -361,6 +362,10 @@ fn mk_decls(
});
let span = DUMMY_SP.apply_mark(mark);
+ let hidden = cx.meta_list_item_word(span, Symbol::intern("hidden"));
+ let doc = cx.meta_list(span, Symbol::intern("doc"), vec![hidden]);
+ let doc_hidden = cx.attribute(span, doc);
+
let proc_macro = Ident::from_str("proc_macro");
let krate = cx.item(span,
proc_macro,
@@ -425,7 +430,7 @@ fn mk_decls(
span,
span,
ast::Ident::with_empty_ctxt(Symbol::gensym("decls")),
- vec![],
+ vec![doc_hidden],
vec![krate, decls_static],
).map(|mut i| {
i.vis = respan(span, ast::VisibilityKind::Public);
diff --git a/src/test/run-pass/impl-trait-in-bindings.rs b/src/test/run-pass/impl-trait-in-bindings.rs
index 9a1f53b48933a..1e3a641b7cf94 100644
--- a/src/test/run-pass/impl-trait-in-bindings.rs
+++ b/src/test/run-pass/impl-trait-in-bindings.rs
@@ -1,4 +1,5 @@
#![feature(impl_trait_in_bindings)]
+//~^ WARN the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
use std::fmt::Debug;
diff --git a/src/test/run-pass/impl-trait-in-bindings.stderr b/src/test/run-pass/impl-trait-in-bindings.stderr
new file mode 100644
index 0000000000000..4896deb9d5c91
--- /dev/null
+++ b/src/test/run-pass/impl-trait-in-bindings.stderr
@@ -0,0 +1,6 @@
+warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
+ --> $DIR/impl-trait-in-bindings.rs:1:12
+ |
+LL | #![feature(impl_trait_in_bindings)]
+ | ^^^^^^^^^^^^^^^^^^^^^^
+
diff --git a/src/test/ui/const-generics/cannot-infer-type-for-const-param.rs b/src/test/ui/const-generics/cannot-infer-type-for-const-param.rs
new file mode 100644
index 0000000000000..c3f5e360fe280
--- /dev/null
+++ b/src/test/ui/const-generics/cannot-infer-type-for-const-param.rs
@@ -0,0 +1,11 @@
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+// We should probably be able to infer the types here. However, this test is checking that we don't
+// get an ICE in this case. It may be modified later to not be an error.
+
+struct Foo<const NUM_BYTES: usize>(pub [u8; NUM_BYTES]);
+
+fn main() {
+ let _ = Foo::<3>([1, 2, 3]); //~ ERROR type annotations needed
+}
diff --git a/src/test/ui/const-generics/cannot-infer-type-for-const-param.stderr b/src/test/ui/const-generics/cannot-infer-type-for-const-param.stderr
new file mode 100644
index 0000000000000..a0641bd2fdc96
--- /dev/null
+++ b/src/test/ui/const-generics/cannot-infer-type-for-const-param.stderr
@@ -0,0 +1,15 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+ --> $DIR/cannot-infer-type-for-const-param.rs:1:12
+ |
+LL | #![feature(const_generics)]
+ | ^^^^^^^^^^^^^^
+
+error[E0282]: type annotations needed
+ --> $DIR/cannot-infer-type-for-const-param.rs:10:19
+ |
+LL | let _ = Foo::<3>([1, 2, 3]);
+ | ^ cannot infer type for `{integer}`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.
diff --git a/src/test/ui/const-generics/invalid-const-arg-for-type-param.rs b/src/test/ui/const-generics/invalid-const-arg-for-type-param.rs
new file mode 100644
index 0000000000000..b069cd89680c1
--- /dev/null
+++ b/src/test/ui/const-generics/invalid-const-arg-for-type-param.rs
@@ -0,0 +1,9 @@
+use std::convert::TryInto;
+
+struct S;
+
+fn main() {
+ let _: u32 = 5i32.try_into::<32>().unwrap(); //~ ERROR wrong number of const arguments
+ S.f::<0>(); //~ ERROR no method named `f`
+ S::<0>; //~ ERROR wrong number of const arguments
+}
diff --git a/src/test/ui/const-generics/invalid-const-arg-for-type-param.stderr b/src/test/ui/const-generics/invalid-const-arg-for-type-param.stderr
new file mode 100644
index 0000000000000..8f3f91651edfb
--- /dev/null
+++ b/src/test/ui/const-generics/invalid-const-arg-for-type-param.stderr
@@ -0,0 +1,25 @@
+error[E0107]: wrong number of const arguments: expected 0, found 1
+ --> $DIR/invalid-const-arg-for-type-param.rs:6:34
+ |
+LL | let _: u32 = 5i32.try_into::<32>().unwrap();
+ | ^^ unexpected const argument
+
+error[E0599]: no method named `f` found for type `S` in the current scope
+ --> $DIR/invalid-const-arg-for-type-param.rs:7:7
+ |
+LL | struct S;
+ | --------- method `f` not found for this
+...
+LL | S.f::<0>();
+ | ^
+
+error[E0107]: wrong number of const arguments: expected 0, found 1
+ --> $DIR/invalid-const-arg-for-type-param.rs:8:9
+ |
+LL | S::<0>;
+ | ^ unexpected const argument
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0107, E0599.
+For more information about an error, try `rustc --explain E0107`.
diff --git a/src/test/ui/impl-trait/bindings-opaque.rs b/src/test/ui/impl-trait/bindings-opaque.rs
index 5f623321943a3..d4eef29ed3207 100644
--- a/src/test/ui/impl-trait/bindings-opaque.rs
+++ b/src/test/ui/impl-trait/bindings-opaque.rs
@@ -1,4 +1,5 @@
#![feature(impl_trait_in_bindings)]
+//~^ WARN the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
const FOO: impl Copy = 42;
diff --git a/src/test/ui/impl-trait/bindings-opaque.stderr b/src/test/ui/impl-trait/bindings-opaque.stderr
index 8b2514c050142..d0a6a4ee578f7 100644
--- a/src/test/ui/impl-trait/bindings-opaque.stderr
+++ b/src/test/ui/impl-trait/bindings-opaque.stderr
@@ -1,17 +1,23 @@
+warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
+ --> $DIR/bindings-opaque.rs:1:12
+ |
+LL | #![feature(impl_trait_in_bindings)]
+ | ^^^^^^^^^^^^^^^^^^^^^^
+
error[E0599]: no method named `count_ones` found for type `impl std::marker::Copy` in the current scope
- --> $DIR/bindings-opaque.rs:10:17
+ --> $DIR/bindings-opaque.rs:11:17
|
LL | let _ = FOO.count_ones();
| ^^^^^^^^^^
error[E0599]: no method named `count_ones` found for type `impl std::marker::Copy` in the current scope
- --> $DIR/bindings-opaque.rs:12:17
+ --> $DIR/bindings-opaque.rs:13:17
|
LL | let _ = BAR.count_ones();
| ^^^^^^^^^^
error[E0599]: no method named `count_ones` found for type `impl std::marker::Copy` in the current scope
- --> $DIR/bindings-opaque.rs:14:17
+ --> $DIR/bindings-opaque.rs:15:17
|
LL | let _ = foo.count_ones();
| ^^^^^^^^^^
diff --git a/src/test/ui/impl-trait/bindings.rs b/src/test/ui/impl-trait/bindings.rs
index 91d092634a901..104a44d65662e 100644
--- a/src/test/ui/impl-trait/bindings.rs
+++ b/src/test/ui/impl-trait/bindings.rs
@@ -1,4 +1,5 @@
#![feature(impl_trait_in_bindings)]
+//~^ WARN the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
fn a<T: Clone>(x: T) {
const foo: impl Clone = x;
diff --git a/src/test/ui/impl-trait/bindings.stderr b/src/test/ui/impl-trait/bindings.stderr
index a5bf583afeaf6..c66836ab8e5af 100644
--- a/src/test/ui/impl-trait/bindings.stderr
+++ b/src/test/ui/impl-trait/bindings.stderr
@@ -1,23 +1,29 @@
+warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
+ --> $DIR/bindings.rs:1:12
+ |
+LL | #![feature(impl_trait_in_bindings)]
+ | ^^^^^^^^^^^^^^^^^^^^^^
+
error[E0435]: attempt to use a non-constant value in a constant
- --> $DIR/bindings.rs:4:29
+ --> $DIR/bindings.rs:5:29
|
LL | const foo: impl Clone = x;
| ^ non-constant value
error[E0435]: attempt to use a non-constant value in a constant
- --> $DIR/bindings.rs:10:33
+ --> $DIR/bindings.rs:11:33
|
LL | const foo: impl Clone = x;
| ^ non-constant value
error[E0435]: attempt to use a non-constant value in a constant
- --> $DIR/bindings.rs:17:33
+ --> $DIR/bindings.rs:18:33
|
LL | const foo: impl Clone = x;
| ^ non-constant value
error[E0435]: attempt to use a non-constant value in a constant
- --> $DIR/bindings.rs:24:33
+ --> $DIR/bindings.rs:25:33
|
LL | const foo: impl Clone = x;
| ^ non-constant value
diff --git a/src/test/ui/nll/issue-55850.rs b/src/test/ui/nll/issue-55850.rs
index 8a016bf87795b..a8f7299f89937 100644
--- a/src/test/ui/nll/issue-55850.rs
+++ b/src/test/ui/nll/issue-55850.rs
@@ -25,7 +25,7 @@ where
fn bug<'a>() -> impl Iterator<Item = &'a str> {
GenIter(move || {
let mut s = String::new();
- yield &s[..] //~ ERROR `s` does not live long enough [E0597]
+ yield &s[..] //~ ERROR cannot yield value referencing local variable `s` [E0515]
//~| ERROR borrow may still be in use when generator yields
})
}
diff --git a/src/test/ui/nll/issue-55850.stderr b/src/test/ui/nll/issue-55850.stderr
index 66c2995efc880..86a8cdc42ff9f 100644
--- a/src/test/ui/nll/issue-55850.stderr
+++ b/src/test/ui/nll/issue-55850.stderr
@@ -1,11 +1,11 @@
-error[E0597]: `s` does not live long enough
- --> $DIR/issue-55850.rs:28:16
+error[E0515]: cannot yield value referencing local variable `s`
+ --> $DIR/issue-55850.rs:28:9
|
LL | yield &s[..]
- | ^ borrowed value does not live long enough
-LL |
-LL | })
- | - `s` dropped here while still borrowed
+ | ^^^^^^^-^^^^
+ | | |
+ | | `s` is borrowed here
+ | yields a value referencing data owned by the current function
error[E0626]: borrow may still be in use when generator yields
--> $DIR/issue-55850.rs:28:16
@@ -15,5 +15,5 @@ LL | yield &s[..]
error: aborting due to 2 previous errors
-Some errors have detailed explanations: E0597, E0626.
-For more information about an error, try `rustc --explain E0597`.
+Some errors have detailed explanations: E0515, E0626.
+For more information about an error, try `rustc --explain E0515`.
diff --git a/src/test/ui/proc-macro/no-missing-docs.rs b/src/test/ui/proc-macro/no-missing-docs.rs
new file mode 100644
index 0000000000000..e5a5f8beb4585
--- /dev/null
+++ b/src/test/ui/proc-macro/no-missing-docs.rs
@@ -0,0 +1,16 @@
+//! Verify that the `decls` module implicitly added by the compiler does not cause `missing_docs`
+//! warnings.
+
+// compile-pass
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![deny(missing_docs)]
+
+extern crate proc_macro;
+use proc_macro::*;
+
+/// Foo1.
+#[proc_macro]
+pub fn foo1(input: TokenStream) -> TokenStream { input }