diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/region_name.rs | 58 | ||||
| -rw-r--r-- | src/test/ui/nll/issue-98170.rs | 25 | ||||
| -rw-r--r-- | src/test/ui/nll/issue-98170.stderr | 44 |
4 files changed, 125 insertions, 5 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs b/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs index 9d81330745f..d359d7efb62 100644 --- a/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs +++ b/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs @@ -62,7 +62,8 @@ impl OutlivesSuggestionBuilder { | RegionNameSource::AnonRegionFromUpvar(..) | RegionNameSource::AnonRegionFromOutput(..) | RegionNameSource::AnonRegionFromYieldTy(..) - | RegionNameSource::AnonRegionFromAsyncFn(..) => { + | RegionNameSource::AnonRegionFromAsyncFn(..) + | RegionNameSource::AnonRegionFromImplSignature(..) => { debug!("Region {:?} is NOT suggestable", name); false } diff --git a/compiler/rustc_borrowck/src/diagnostics/region_name.rs b/compiler/rustc_borrowck/src/diagnostics/region_name.rs index 1db4b902f71..8f3699553d9 100644 --- a/compiler/rustc_borrowck/src/diagnostics/region_name.rs +++ b/compiler/rustc_borrowck/src/diagnostics/region_name.rs @@ -6,7 +6,7 @@ use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_middle::ty::print::RegionHighlightMode; use rustc_middle::ty::subst::{GenericArgKind, SubstsRef}; -use rustc_middle::ty::{self, RegionVid, Ty}; +use rustc_middle::ty::{self, DefIdTree, RegionVid, Ty}; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; @@ -45,6 +45,8 @@ pub(crate) enum RegionNameSource { AnonRegionFromYieldTy(Span, String), /// An anonymous region from an async fn. AnonRegionFromAsyncFn(Span), + /// An anonymous region from an impl self type or trait + AnonRegionFromImplSignature(Span, &'static str), } /// Describes what to highlight to explain to the user that we're giving an anonymous region a @@ -75,7 +77,8 @@ impl RegionName { | RegionNameSource::AnonRegionFromUpvar(..) | RegionNameSource::AnonRegionFromOutput(..) | RegionNameSource::AnonRegionFromYieldTy(..) - | RegionNameSource::AnonRegionFromAsyncFn(..) => false, + | RegionNameSource::AnonRegionFromAsyncFn(..) + | RegionNameSource::AnonRegionFromImplSignature(..) => false, } } @@ -87,7 +90,8 @@ impl RegionName { | RegionNameSource::SynthesizedFreeEnvRegion(span, _) | RegionNameSource::AnonRegionFromUpvar(span, _) | RegionNameSource::AnonRegionFromYieldTy(span, _) - | RegionNameSource::AnonRegionFromAsyncFn(span) => Some(span), + | RegionNameSource::AnonRegionFromAsyncFn(span) + | RegionNameSource::AnonRegionFromImplSignature(span, _) => Some(span), RegionNameSource::AnonRegionFromArgument(ref highlight) | RegionNameSource::AnonRegionFromOutput(ref highlight, _) => match *highlight { RegionNameHighlight::MatchedHirTy(span) @@ -166,6 +170,12 @@ impl RegionName { RegionNameSource::AnonRegionFromYieldTy(span, type_name) => { diag.span_label(*span, format!("yield type is {type_name}")); } + RegionNameSource::AnonRegionFromImplSignature(span, location) => { + diag.span_label( + *span, + format!("lifetime `{self}` appears in the `impl`'s {location}"), + ); + } RegionNameSource::Static => {} } } @@ -240,7 +250,8 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> { .or_else(|| self.give_name_if_anonymous_region_appears_in_arguments(fr)) .or_else(|| self.give_name_if_anonymous_region_appears_in_upvars(fr)) .or_else(|| self.give_name_if_anonymous_region_appears_in_output(fr)) - .or_else(|| self.give_name_if_anonymous_region_appears_in_yield_ty(fr)); + .or_else(|| self.give_name_if_anonymous_region_appears_in_yield_ty(fr)) + .or_else(|| self.give_name_if_anonymous_region_appears_in_impl_signature(fr)); if let Some(ref value) = value { self.region_names.try_borrow_mut().unwrap().insert(fr, value.clone()); @@ -847,4 +858,43 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> { source: RegionNameSource::AnonRegionFromYieldTy(yield_span, type_name), }) } + + fn give_name_if_anonymous_region_appears_in_impl_signature( + &self, + fr: RegionVid, + ) -> Option<RegionName> { + let ty::ReEarlyBound(region) = *self.to_error_region(fr)? else { + return None; + }; + if region.has_name() { + return None; + }; + + let tcx = self.infcx.tcx; + let body_parent_did = tcx.opt_parent(self.mir_def_id().to_def_id())?; + if tcx.parent(region.def_id) != body_parent_did + || tcx.def_kind(body_parent_did) != DefKind::Impl + { + return None; + } + + let mut found = false; + tcx.fold_regions(tcx.type_of(body_parent_did), &mut true, |r: ty::Region<'tcx>, _| { + if *r == ty::ReEarlyBound(region) { + found = true; + } + r + }); + + Some(RegionName { + name: self.synthesize_region_name(), + source: RegionNameSource::AnonRegionFromImplSignature( + tcx.def_span(region.def_id), + // FIXME(compiler-errors): Does this ever actually show up + // anywhere other than the self type? I couldn't create an + // example of a `'_` in the impl's trait being referenceable. + if found { "self type" } else { "header" }, + ), + }) + } } diff --git a/src/test/ui/nll/issue-98170.rs b/src/test/ui/nll/issue-98170.rs new file mode 100644 index 00000000000..6bb12f52d3f --- /dev/null +++ b/src/test/ui/nll/issue-98170.rs @@ -0,0 +1,25 @@ +pub struct MyStruct<'a> { + field: &'a [u32], +} + +impl MyStruct<'_> { + pub fn new<'a>(field: &'a [u32]) -> MyStruct<'a> { + Self { field } + //~^ ERROR lifetime may not live long enough + //~| ERROR lifetime may not live long enough + } +} + +trait Trait<'a> { + fn new(field: &'a [u32]) -> MyStruct<'a>; +} + +impl<'a> Trait<'a> for MyStruct<'_> { + fn new(field: &'a [u32]) -> MyStruct<'a> { + Self { field } + //~^ ERROR lifetime may not live long enough + //~| ERROR lifetime may not live long enough + } +} + +fn main() {} diff --git a/src/test/ui/nll/issue-98170.stderr b/src/test/ui/nll/issue-98170.stderr new file mode 100644 index 00000000000..0d17365e71b --- /dev/null +++ b/src/test/ui/nll/issue-98170.stderr @@ -0,0 +1,44 @@ +error: lifetime may not live long enough + --> $DIR/issue-98170.rs:7:9 + | +LL | impl MyStruct<'_> { + | -- lifetime `'1` appears in the `impl`'s self type +LL | pub fn new<'a>(field: &'a [u32]) -> MyStruct<'a> { + | -- lifetime `'a` defined here +LL | Self { field } + | ^^^^^^^^^^^^^^ associated function was supposed to return data with lifetime `'a` but it is returning data with lifetime `'1` + +error: lifetime may not live long enough + --> $DIR/issue-98170.rs:7:16 + | +LL | impl MyStruct<'_> { + | -- lifetime `'1` appears in the `impl`'s self type +LL | pub fn new<'a>(field: &'a [u32]) -> MyStruct<'a> { + | -- lifetime `'a` defined here +LL | Self { field } + | ^^^^^ this usage requires that `'a` must outlive `'1` + +error: lifetime may not live long enough + --> $DIR/issue-98170.rs:19:9 + | +LL | impl<'a> Trait<'a> for MyStruct<'_> { + | -- -- lifetime `'1` appears in the `impl`'s self type + | | + | lifetime `'a` defined here +LL | fn new(field: &'a [u32]) -> MyStruct<'a> { +LL | Self { field } + | ^^^^^^^^^^^^^^ associated function was supposed to return data with lifetime `'a` but it is returning data with lifetime `'1` + +error: lifetime may not live long enough + --> $DIR/issue-98170.rs:19:16 + | +LL | impl<'a> Trait<'a> for MyStruct<'_> { + | -- -- lifetime `'1` appears in the `impl`'s self type + | | + | lifetime `'a` defined here +LL | fn new(field: &'a [u32]) -> MyStruct<'a> { +LL | Self { field } + | ^^^^^ this usage requires that `'a` must outlive `'1` + +error: aborting due to 4 previous errors + |