From ca7df9a2a9c4b1f751e91040fe659f682c976919 Mon Sep 17 00:00:00 2001 From: Rejyr Date: Wed, 9 Nov 2022 19:34:49 -0500 Subject: [PATCH] migrate: `for_loops_over_fallibles.rs` --- .../locales/en-US/lint.ftl | 7 ++ .../src/for_loops_over_fallibles.rs | 73 +++++++------------ compiler/rustc_lint/src/lints.rs | 49 +++++++++++++ 3 files changed, 84 insertions(+), 45 deletions(-) diff --git a/compiler/rustc_error_messages/locales/en-US/lint.ftl b/compiler/rustc_error_messages/locales/en-US/lint.ftl index 1080ba2d2b5..5330ce504b2 100644 --- a/compiler/rustc_error_messages/locales/en-US/lint.ftl +++ b/compiler/rustc_error_messages/locales/en-US/lint.ftl @@ -16,6 +16,13 @@ lint_enum_intrinsics_mem_variant = lint_expectation = this lint expectation is unfulfilled .note = the `unfulfilled_lint_expectations` lint can't be expected and will always produce this message +lint_for_loops_over_fallibles = + for loop over {$article} `{$ty}`. This is more readably written as an `if let` statement + .suggestion = consider using `if let` to clear intent + .remove_next = to iterate over `{$recv_snip}` remove the call to `next` + .use_while_let = to check pattern in a loop use `while let` + .use_question_mark = consider unwrapping the `Result` with `?` to iterate over its contents + lint_non_binding_let_on_sync_lock = non-binding let on a synchronization lock diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs index 182734fa9fc..7526b8c0632 100644 --- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs +++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs @@ -1,7 +1,14 @@ -use crate::{LateContext, LateLintPass, LintContext}; +#![deny(rustc::untranslatable_diagnostic)] +#![deny(rustc::diagnostic_outside_of_impl)] +use crate::{ + lints::{ + ForLoopsOverFalliblesDiag, ForLoopsOverFalliblesLoopSub, ForLoopsOverFalliblesQuestionMark, + ForLoopsOverFalliblesSuggestion, + }, + LateContext, LateLintPass, LintContext, +}; use hir::{Expr, Pat}; -use rustc_errors::{Applicability, DelayDm}; use rustc_hir as hir; use rustc_infer::{infer::TyCtxtInferExt, traits::ObligationCause}; use rustc_middle::ty::{self, List}; @@ -53,53 +60,29 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles { _ => return, }; - let msg = DelayDm(|| { - format!( - "for loop over {article} `{ty}`. This is more readably written as an `if let` statement", - ) - }); - - cx.struct_span_lint(FOR_LOOPS_OVER_FALLIBLES, arg.span, msg, |lint| { - if let Some(recv) = extract_iterator_next_call(cx, arg) + let sub = if let Some(recv) = extract_iterator_next_call(cx, arg) && let Ok(recv_snip) = cx.sess().source_map().span_to_snippet(recv.span) { - lint.span_suggestion( - recv.span.between(arg.span.shrink_to_hi()), - format!("to iterate over `{recv_snip}` remove the call to `next`"), - ".by_ref()", - Applicability::MaybeIncorrect - ); + ForLoopsOverFalliblesLoopSub::RemoveNext { suggestion: recv.span.between(arg.span.shrink_to_hi()), recv_snip } } else { - lint.multipart_suggestion_verbose( - "to check pattern in a loop use `while let`", - vec![ - // NB can't use `until` here because `expr.span` and `pat.span` have different syntax contexts - (expr.span.with_hi(pat.span.lo()), format!("while let {var}(")), - (pat.span.between(arg.span), ") = ".to_string()), - ], - Applicability::MaybeIncorrect - ); - } + ForLoopsOverFalliblesLoopSub::UseWhileLet { start_span: expr.span.with_hi(pat.span.lo()), end_span: pat.span.between(arg.span), var } + } ; + let question_mark = if suggest_question_mark(cx, adt, substs, expr.span) { + Some(ForLoopsOverFalliblesQuestionMark { suggestion: arg.span.shrink_to_hi() }) + } else { + None + }; + let suggestion = ForLoopsOverFalliblesSuggestion { + var, + start_span: expr.span.with_hi(pat.span.lo()), + end_span: pat.span.between(arg.span), + }; - if suggest_question_mark(cx, adt, substs, expr.span) { - lint.span_suggestion( - arg.span.shrink_to_hi(), - "consider unwrapping the `Result` with `?` to iterate over its contents", - "?", - Applicability::MaybeIncorrect, - ); - } - - lint.multipart_suggestion_verbose( - "consider using `if let` to clear intent", - vec![ - // NB can't use `until` here because `expr.span` and `pat.span` have different syntax contexts - (expr.span.with_hi(pat.span.lo()), format!("if let {var}(")), - (pat.span.between(arg.span), ") = ".to_string()), - ], - Applicability::MaybeIncorrect, - ) - }) + cx.emit_spanned_lint( + FOR_LOOPS_OVER_FALLIBLES, + arg.span, + ForLoopsOverFalliblesDiag { article, ty, sub, question_mark, suggestion }, + ); } } diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 782cf668b29..a3549346604 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -333,6 +333,55 @@ impl<'a> DecorateLint<'a, ()> for Expectation<'_> { } } +// for_loops_over_fallibles.rs +#[derive(LintDiagnostic)] +#[diag(lint_for_loops_over_fallibles)] +pub struct ForLoopsOverFalliblesDiag<'a> { + pub article: &'static str, + pub ty: &'static str, + #[subdiagnostic] + pub sub: ForLoopsOverFalliblesLoopSub<'a>, + #[subdiagnostic] + pub question_mark: Option, + #[subdiagnostic] + pub suggestion: ForLoopsOverFalliblesSuggestion<'a>, +} + +#[derive(Subdiagnostic)] +pub enum ForLoopsOverFalliblesLoopSub<'a> { + #[suggestion(remove_next, code = ".by_ref()", applicability = "maybe-incorrect")] + RemoveNext { + #[primary_span] + suggestion: Span, + recv_snip: String, + }, + #[multipart_suggestion(use_while_let, applicability = "maybe-incorrect")] + UseWhileLet { + #[suggestion_part(code = "while let {var}(")] + start_span: Span, + #[suggestion_part(code = ") = ")] + end_span: Span, + var: &'a str, + }, +} + +#[derive(Subdiagnostic)] +#[suggestion(use_question_mark, code = "?", applicability = "maybe-incorrect")] +pub struct ForLoopsOverFalliblesQuestionMark { + #[primary_span] + pub suggestion: Span, +} + +#[derive(Subdiagnostic)] +#[multipart_suggestion(suggestion, applicability = "maybe-incorrect")] +pub struct ForLoopsOverFalliblesSuggestion<'a> { + pub var: &'a str, + #[suggestion_part(code = "if let {var}(")] + pub start_span: Span, + #[suggestion_part(code = ") = ")] + pub end_span: Span, +} + // internal.rs #[derive(LintDiagnostic)] #[diag(lint_default_hash_types)]