From 232aaeba7c6779233659b0a57ed75a5d7a48cfb0 Mon Sep 17 00:00:00 2001 From: Georg Semmler Date: Wed, 11 Oct 2023 21:57:53 +0200 Subject: [PATCH] Handle several `#[diagnostic::on_unimplemented]` attributes correctly This PR fixes an issues where rustc would ignore subsequent `#[diagnostic::on_unimplemented]` attributes. The [corresponding RFC](https://rust-lang.github.io/rfcs/3368-diagnostic-attribute-namespace.html) specifies that the first matching instance of each option is used. Invalid attributes are linted and otherwise ignored. --- .../error_reporting/on_unimplemented.rs | 46 +++++++++++----- ...ed_options_and_continue_to_use_fallback.rs | 22 ++++++++ ...ptions_and_continue_to_use_fallback.stderr | 52 +++++++++++++++++++ 3 files changed, 108 insertions(+), 12 deletions(-) create mode 100644 tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs create mode 100644 tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs index d9059e46a8c..cc1f13a2f0f 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs @@ -1,6 +1,6 @@ use super::{ObligationCauseCode, PredicateObligation}; use crate::infer::error_reporting::TypeErrCtxt; -use rustc_ast::{MetaItem, NestedMetaItem}; +use rustc_ast::{Attribute, MetaItem, NestedMetaItem}; use rustc_attr as attr; use rustc_data_structures::fx::FxHashMap; use rustc_errors::{struct_span_err, ErrorGuaranteed}; @@ -474,18 +474,40 @@ fn parse( } pub fn of_item(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> Result, ErrorGuaranteed> { - let mut is_diagnostic_namespace_variant = false; - let Some(attr) = tcx.get_attr(item_def_id, sym::rustc_on_unimplemented).or_else(|| { - if tcx.features().diagnostic_namespace { - is_diagnostic_namespace_variant = true; - tcx.get_attrs_by_path(item_def_id, &[sym::diagnostic, sym::on_unimplemented]).next() - } else { - None - } - }) else { - return Ok(None); - }; + if let Some(attr) = tcx.get_attr(item_def_id, sym::rustc_on_unimplemented) { + return Self::parse_attribute(attr, false, tcx, item_def_id); + } else if tcx.features().diagnostic_namespace { + tcx.get_attrs_by_path(item_def_id, &[sym::diagnostic, sym::on_unimplemented]) + .filter_map(|attr| Self::parse_attribute(attr, true, tcx, item_def_id).transpose()) + .try_fold(None, |aggr: Option, directive| { + let directive = directive?; + if let Some(aggr) = aggr { + let mut subcommands = aggr.subcommands; + subcommands.extend(directive.subcommands); + Ok(Some(Self { + condition: aggr.condition.or(directive.condition), + subcommands, + message: aggr.message.or(directive.message), + label: aggr.label.or(directive.label), + note: aggr.note.or(directive.note), + parent_label: aggr.parent_label.or(directive.parent_label), + append_const_msg: aggr.append_const_msg.or(directive.append_const_msg), + })) + } else { + Ok(Some(directive)) + } + }) + } else { + Ok(None) + } + } + fn parse_attribute( + attr: &Attribute, + is_diagnostic_namespace_variant: bool, + tcx: TyCtxt<'tcx>, + item_def_id: DefId, + ) -> Result, ErrorGuaranteed> { let result = if let Some(items) = attr.meta_item_list() { Self::parse(tcx, item_def_id, &items, attr.span, true, is_diagnostic_namespace_variant) } else if let Some(value) = attr.value_str() { diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs new file mode 100644 index 00000000000..35307586391 --- /dev/null +++ b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs @@ -0,0 +1,22 @@ +#![feature(diagnostic_namespace)] + +#[diagnostic::on_unimplemented( + //~^WARN malformed `on_unimplemented` attribute + //~|WARN malformed `on_unimplemented` attribute + if(Self = ()), + message = "not used yet", + label = "not used yet", + note = "not used yet" +)] +#[diagnostic::on_unimplemented(message = "fallback!!")] +#[diagnostic::on_unimplemented(label = "fallback label")] +#[diagnostic::on_unimplemented(note = "fallback note")] +#[diagnostic::on_unimplemented(message = "fallback2!!")] +trait Foo {} + +fn takes_foo(_: impl Foo) {} + +fn main() { + takes_foo(()); + //~^ERROR fallback!! +} diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr new file mode 100644 index 00000000000..6a83d8e39c6 --- /dev/null +++ b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr @@ -0,0 +1,52 @@ +warning: malformed `on_unimplemented` attribute + --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:3:1 + | +LL | / #[diagnostic::on_unimplemented( +LL | | +LL | | +LL | | if(Self = ()), +... | +LL | | note = "not used yet" +LL | | )] + | |__^ + | + = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default + +warning: malformed `on_unimplemented` attribute + --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:3:1 + | +LL | / #[diagnostic::on_unimplemented( +LL | | +LL | | +LL | | if(Self = ()), +... | +LL | | note = "not used yet" +LL | | )] + | |__^ + | + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + +error[E0277]: fallback!! + --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:20:15 + | +LL | takes_foo(()); + | --------- ^^ fallback label + | | + | required by a bound introduced by this call + | + = help: the trait `Foo` is not implemented for `()` + = note: fallback note +help: this trait has no implementations, consider adding one + --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:15:1 + | +LL | trait Foo {} + | ^^^^^^^^^ +note: required by a bound in `takes_foo` + --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:17:22 + | +LL | fn takes_foo(_: impl Foo) {} + | ^^^ required by this bound in `takes_foo` + +error: aborting due to previous error; 2 warnings emitted + +For more information about this error, try `rustc --explain E0277`.