diff options
| -rw-r--r-- | compiler/rustc_parse/messages.ftl | 4 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/errors.rs | 26 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 48 | ||||
| -rw-r--r-- | tests/ui/expr/if/bad-if-let-suggestion.rs | 3 | ||||
| -rw-r--r-- | tests/ui/expr/if/bad-if-let-suggestion.stderr | 22 | ||||
| -rw-r--r-- | tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.stderr | 8 |
6 files changed, 93 insertions, 18 deletions
diff --git a/compiler/rustc_parse/messages.ftl b/compiler/rustc_parse/messages.ftl index 49a2c414467..352a55a7cbc 100644 --- a/compiler/rustc_parse/messages.ftl +++ b/compiler/rustc_parse/messages.ftl @@ -492,9 +492,13 @@ parse_match_arm_body_without_braces = `match` arm body without braces } with a body .suggestion_use_comma_not_semicolon = replace `;` with `,` to end a `match` arm expression +parse_maybe_comparison = you might have meant to compare for equality + parse_maybe_fn_typo_with_impl = you might have meant to write `impl` instead of `fn` .suggestion = replace `fn` with `impl` here +parse_maybe_missing_let = you might have meant to continue the let-chain + parse_maybe_recover_from_bad_qpath_stage_2 = missing angle brackets in associated item path .suggestion = types that don't start with an identifier need to be surrounded with angle brackets in qualified paths diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs index 7ce348619c6..81232f189e1 100644 --- a/compiler/rustc_parse/src/errors.rs +++ b/compiler/rustc_parse/src/errors.rs @@ -407,6 +407,32 @@ pub(crate) struct ExpectedExpressionFoundLet { pub span: Span, #[subdiagnostic] pub reason: ForbiddenLetReason, + #[subdiagnostic] + pub missing_let: Option<MaybeMissingLet>, + #[subdiagnostic] + pub comparison: Option<MaybeComparison>, +} + +#[derive(Subdiagnostic, Clone, Copy)] +#[multipart_suggestion( + parse_maybe_missing_let, + applicability = "maybe-incorrect", + style = "verbose" +)] +pub(crate) struct MaybeMissingLet { + #[suggestion_part(code = "let ")] + pub span: Span, +} + +#[derive(Subdiagnostic, Clone, Copy)] +#[multipart_suggestion( + parse_maybe_comparison, + applicability = "maybe-incorrect", + style = "verbose" +)] +pub(crate) struct MaybeComparison { + #[suggestion_part(code = "=")] + pub span: Span, } #[derive(Diagnostic)] diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index 79567eb3898..e334837c1d4 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -1,3 +1,4 @@ +// ignore-tidy-filelength use super::diagnostics::SnapshotParser; use super::pat::{CommaRecoveryMode, Expected, RecoverColon, RecoverComma}; use super::ty::{AllowPlus, RecoverQPath, RecoverReturnSign}; @@ -2477,7 +2478,7 @@ impl<'a> Parser<'a> { let mut cond = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL | Restrictions::ALLOW_LET, None)?; - CondChecker { parser: self, forbid_let_reason: None }.visit_expr(&mut cond); + CondChecker::new(self).visit_expr(&mut cond); if let ExprKind::Let(_, _, _, None) = cond.kind { // Remove the last feature gating of a `let` expression since it's stable. @@ -2493,6 +2494,8 @@ impl<'a> Parser<'a> { let err = errors::ExpectedExpressionFoundLet { span: self.token.span, reason: ForbiddenLetReason::OtherForbidden, + missing_let: None, + comparison: None, }; if self.prev_token.kind == token::BinOp(token::Or) { // This was part of a closure, the that part of the parser recover. @@ -2876,7 +2879,7 @@ impl<'a> Parser<'a> { let if_span = this.prev_token.span; let mut cond = this.parse_match_guard_condition()?; - CondChecker { parser: this, forbid_let_reason: None }.visit_expr(&mut cond); + CondChecker::new(this).visit_expr(&mut cond); let (has_let_expr, does_not_have_bin_op) = check_let_expr(&cond); if has_let_expr { @@ -3552,6 +3555,14 @@ pub(crate) enum ForbiddenLetReason { struct CondChecker<'a> { parser: &'a Parser<'a>, forbid_let_reason: Option<ForbiddenLetReason>, + missing_let: Option<errors::MaybeMissingLet>, + comparison: Option<errors::MaybeComparison>, +} + +impl<'a> CondChecker<'a> { + fn new(parser: &'a Parser<'a>) -> Self { + CondChecker { parser, forbid_let_reason: None, missing_let: None, comparison: None } + } } impl MutVisitor for CondChecker<'_> { @@ -3562,11 +3573,13 @@ impl MutVisitor for CondChecker<'_> { match e.kind { ExprKind::Let(_, _, _, ref mut is_recovered @ None) => { if let Some(reason) = self.forbid_let_reason { - *is_recovered = Some( - self.parser - .sess - .emit_err(errors::ExpectedExpressionFoundLet { span, reason }), - ); + *is_recovered = + Some(self.parser.sess.emit_err(errors::ExpectedExpressionFoundLet { + span, + reason, + missing_let: self.missing_let, + comparison: self.comparison, + })); } else { self.parser.sess.gated_spans.gate(sym::let_chains, span); } @@ -3590,9 +3603,28 @@ impl MutVisitor for CondChecker<'_> { noop_visit_expr(e, self); self.forbid_let_reason = forbid_let_reason; } + ExprKind::Assign(ref lhs, _, span) => { + let forbid_let_reason = self.forbid_let_reason; + self.forbid_let_reason = Some(OtherForbidden); + let missing_let = self.missing_let; + if let ExprKind::Binary(_, _, rhs) = &lhs.kind + && let ExprKind::Path(_, _) + | ExprKind::Struct(_) + | ExprKind::Call(_, _) + | ExprKind::Array(_) = rhs.kind + { + self.missing_let = + Some(errors::MaybeMissingLet { span: rhs.span.shrink_to_lo() }); + } + let comparison = self.comparison; + self.comparison = Some(errors::MaybeComparison { span: span.shrink_to_hi() }); + noop_visit_expr(e, self); + self.forbid_let_reason = forbid_let_reason; + self.missing_let = missing_let; + self.comparison = comparison; + } ExprKind::Unary(_, _) | ExprKind::Await(_, _) - | ExprKind::Assign(_, _, _) | ExprKind::AssignOp(_, _, _) | ExprKind::Range(_, _, _) | ExprKind::Try(_) diff --git a/tests/ui/expr/if/bad-if-let-suggestion.rs b/tests/ui/expr/if/bad-if-let-suggestion.rs index 99d584ac7a5..b0d0676e1ea 100644 --- a/tests/ui/expr/if/bad-if-let-suggestion.rs +++ b/tests/ui/expr/if/bad-if-let-suggestion.rs @@ -1,6 +1,3 @@ -// FIXME(compiler-errors): This really should suggest `let` on the RHS of the -// `&&` operator, but that's kinda hard to do because of precedence. -// Instead, for now we just make sure not to suggest `if let let`. fn a() { if let x = 1 && i = 2 {} //~^ ERROR cannot find value `i` in this scope diff --git a/tests/ui/expr/if/bad-if-let-suggestion.stderr b/tests/ui/expr/if/bad-if-let-suggestion.stderr index 20ac9ca76ba..0d1f895bd82 100644 --- a/tests/ui/expr/if/bad-if-let-suggestion.stderr +++ b/tests/ui/expr/if/bad-if-let-suggestion.stderr @@ -1,19 +1,27 @@ error: expected expression, found `let` statement - --> $DIR/bad-if-let-suggestion.rs:5:8 + --> $DIR/bad-if-let-suggestion.rs:2:8 | LL | if let x = 1 && i = 2 {} | ^^^^^^^^^ | = note: only supported directly in conditions of `if` and `while` expressions +help: you might have meant to continue the let-chain + | +LL | if let x = 1 && let i = 2 {} + | +++ +help: you might have meant to compare for equality + | +LL | if let x = 1 && i == 2 {} + | + error[E0425]: cannot find value `i` in this scope - --> $DIR/bad-if-let-suggestion.rs:5:21 + --> $DIR/bad-if-let-suggestion.rs:2:21 | LL | if let x = 1 && i = 2 {} | ^ not found in this scope error[E0425]: cannot find value `i` in this scope - --> $DIR/bad-if-let-suggestion.rs:12:9 + --> $DIR/bad-if-let-suggestion.rs:9:9 | LL | fn a() { | ------ similarly named function `a` defined here @@ -22,7 +30,7 @@ LL | if (i + j) = i {} | ^ help: a function with a similar name exists: `a` error[E0425]: cannot find value `j` in this scope - --> $DIR/bad-if-let-suggestion.rs:12:13 + --> $DIR/bad-if-let-suggestion.rs:9:13 | LL | fn a() { | ------ similarly named function `a` defined here @@ -31,7 +39,7 @@ LL | if (i + j) = i {} | ^ help: a function with a similar name exists: `a` error[E0425]: cannot find value `i` in this scope - --> $DIR/bad-if-let-suggestion.rs:12:18 + --> $DIR/bad-if-let-suggestion.rs:9:18 | LL | fn a() { | ------ similarly named function `a` defined here @@ -40,7 +48,7 @@ LL | if (i + j) = i {} | ^ help: a function with a similar name exists: `a` error[E0425]: cannot find value `x` in this scope - --> $DIR/bad-if-let-suggestion.rs:19:8 + --> $DIR/bad-if-let-suggestion.rs:16:8 | LL | fn a() { | ------ similarly named function `a` defined here @@ -49,7 +57,7 @@ LL | if x[0] = 1 {} | ^ help: a function with a similar name exists: `a` error[E0308]: mismatched types - --> $DIR/bad-if-let-suggestion.rs:5:8 + --> $DIR/bad-if-let-suggestion.rs:2:8 | LL | if let x = 1 && i = 2 {} | ^^^^^^^^^^^^^^^^^^ expected `bool`, found `()` diff --git a/tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.stderr b/tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.stderr index 247fad2e992..f3726166eba 100644 --- a/tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.stderr +++ b/tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.stderr @@ -29,6 +29,10 @@ LL | if let Some(elem) = _opt && [1, 2, 3][let _ = &&let Some(x) = Some( | ^^^^^^^^^^^^^^^^^^^^^ | = note: only supported directly in conditions of `if` and `while` expressions +help: you might have meant to compare for equality + | +LL | if let Some(elem) = _opt && [1, 2, 3][let _ = &&let Some(x) = Some(42)] == 1 { + | + error: expected expression, found `let` statement --> $DIR/invalid-let-in-a-valid-let-context.rs:24:23 @@ -53,6 +57,10 @@ LL | if let Some(elem) = _opt && [1, 2, 3][let _ = ()] = 1 { | ^^^^^^^^^^^^^^^^^^^^^ | = note: only supported directly in conditions of `if` and `while` expressions +help: you might have meant to compare for equality + | +LL | if let Some(elem) = _opt && [1, 2, 3][let _ = ()] == 1 { + | + error: expected expression, found `let` statement --> $DIR/invalid-let-in-a-valid-let-context.rs:42:21 |