From d6e34ad108dc998e9f9d872e807e221c0df4f24b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar> Date: Thu, 15 Jul 2021 08:36:19 -0700 Subject: [PATCH] When recovering from a `:` in a pattern, use adequate AST pattern --- compiler/rustc_parse/src/parser/pat.rs | 103 +++++++++++++++--- .../issues/issue-87086-colon-path-sep.rs | 31 ++++-- .../issues/issue-87086-colon-path-sep.stderr | 60 ++++++---- 3 files changed, 150 insertions(+), 44 deletions(-) diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs index bb3947bb47a25..c1f5c569cf09f 100644 --- a/compiler/rustc_parse/src/parser/pat.rs +++ b/compiler/rustc_parse/src/parser/pat.rs @@ -3,13 +3,17 @@ use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole}; use rustc_ast::mut_visit::{noop_visit_pat, MutVisitor}; use rustc_ast::ptr::P; use rustc_ast::token; -use rustc_ast::{self as ast, AttrVec, Attribute, MacCall, Pat, PatField, PatKind, RangeEnd}; -use rustc_ast::{BindingMode, Expr, ExprKind, Mutability, Path, QSelf, RangeSyntax}; +use rustc_ast::{ + self as ast, AttrVec, Attribute, BindingMode, Expr, ExprKind, MacCall, Mutability, Pat, + PatField, PatKind, Path, PathSegment, QSelf, RangeEnd, RangeSyntax, +}; use rustc_ast_pretty::pprust; use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, PResult}; use rustc_span::source_map::{respan, Span, Spanned}; use rustc_span::symbol::{kw, sym, Ident}; +use std::mem::take; + type Expected = Option<&'static str>; /// `Expected` for function and lambda parameter patterns. @@ -101,11 +105,8 @@ impl<'a> Parser<'a> { let mut first_pat = first_pat; if let (RecoverColon::Yes, token::Colon) = (ra, &self.token.kind) { - if matches!( - first_pat.kind, - PatKind::Ident(BindingMode::ByValue(Mutability::Not), _, None) - | PatKind::Path(..) - ) && self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident()) + if matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..)) + && self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident()) { // The pattern looks like it might be a path with a `::` -> `:` typo: // `match foo { bar:baz => {} }` @@ -126,17 +127,87 @@ impl<'a> Parser<'a> { err.cancel(); *self = snapshot; } - Ok(pat) => { + Ok(mut pat) => { // We've parsed the rest of the pattern. - err.span_suggestion( - span, - "maybe write a path separator here", - "::".to_string(), - Applicability::MachineApplicable, - ); + let new_span = first_pat.span.to(pat.span); + let mut show_sugg = false; + match &mut pat.kind { + PatKind::Struct(qself @ None, path, ..) + | PatKind::TupleStruct(qself @ None, path, _) + | PatKind::Path(qself @ None, path) => { + match &first_pat.kind { + PatKind::Ident(_, ident, _) => { + path.segments.insert( + 0, + PathSegment::from_ident(ident.clone()), + ); + path.span = new_span; + show_sugg = true; + first_pat = pat; + } + PatKind::Path(old_qself, old_path) => { + path.segments = old_path + .segments + .iter() + .cloned() + .chain(take(&mut path.segments)) + .collect(); + path.span = new_span; + *qself = old_qself.clone(); + first_pat = pat; + show_sugg = true; + } + _ => {} + } + } + PatKind::Ident( + BindingMode::ByValue(Mutability::Not), + ident, + None, + ) => match &first_pat.kind { + PatKind::Ident(_, old_ident, _) => { + let path = PatKind::Path( + None, + Path { + span: new_span, + segments: vec![ + PathSegment::from_ident( + old_ident.clone(), + ), + PathSegment::from_ident(ident.clone()), + ], + tokens: None, + }, + ); + first_pat = self.mk_pat(new_span, path); + show_sugg = true; + } + PatKind::Path(old_qself, old_path) => { + let mut segments = old_path.segments.clone(); + segments + .push(PathSegment::from_ident(ident.clone())); + let path = PatKind::Path( + old_qself.clone(), + Path { span: new_span, segments, tokens: None }, + ); + first_pat = self.mk_pat(new_span, path); + show_sugg = true; + } + _ => {} + }, + _ => {} + } + if show_sugg { + err.span_suggestion( + span, + "maybe write a path separator here", + "::".to_string(), + Applicability::MachineApplicable, + ); + } else { + first_pat = self.mk_pat(new_span, PatKind::Wild); + } err.emit(); - first_pat = - self.mk_pat(first_pat.span.to(pat.span), PatKind::Wild); } } } diff --git a/src/test/ui/parser/issues/issue-87086-colon-path-sep.rs b/src/test/ui/parser/issues/issue-87086-colon-path-sep.rs index 4ee0b2054ff77..0b7b67496d6f3 100644 --- a/src/test/ui/parser/issues/issue-87086-colon-path-sep.rs +++ b/src/test/ui/parser/issues/issue-87086-colon-path-sep.rs @@ -1,11 +1,15 @@ // Tests that a suggestion is issued if the user wrote a colon instead of // a path separator in a match arm. -enum Foo { - Bar, - Baz, +mod qux { + pub enum Foo { + Bar, + Baz, + } } +use qux::Foo; + fn f() -> Foo { Foo::Bar } fn g1() { @@ -16,24 +20,24 @@ fn g1() { _ => {} } match f() { - Foo::Bar:Baz => {} + qux::Foo:Bar => {} //~^ ERROR: expected one of //~| HELP: maybe write a path separator here _ => {} } match f() { - Foo:Bar::Baz => {} + qux:Foo::Baz => {} //~^ ERROR: expected one of //~| HELP: maybe write a path separator here _ => {} } match f() { - Foo: Bar::Baz if true => {} + qux: Foo::Baz if true => {} //~^ ERROR: expected one of //~| HELP: maybe write a path separator here _ => {} } - if let Bar:Baz = f() { + if let Foo:Bar = f() { //~^ ERROR: expected one of //~| HELP: maybe write a path separator here } @@ -41,16 +45,18 @@ fn g1() { fn g1_neg() { match f() { - ref Foo: Bar::Baz => {} + ref qux: Foo::Baz => {} //~^ ERROR: expected one of + //~| HELP: maybe write a path separator here _ => {} } } fn g2_neg() { match f() { - mut Foo: Bar::Baz => {} + mut qux: Foo::Baz => {} //~^ ERROR: expected one of + //~| HELP: maybe write a path separator here _ => {} } } @@ -62,5 +68,12 @@ fn main() { Foo:Bar::Baz => {} //~^ ERROR: expected one of //~| HELP: maybe write a path separator here + //~| ERROR: failed to resolve: `Bar` is a variant, not a module + } + match myfoo { + Foo::Bar => {} + Foo:Bar => {} + //~^ ERROR: expected one of + //~| HELP: maybe write a path separator here } } diff --git a/src/test/ui/parser/issues/issue-87086-colon-path-sep.stderr b/src/test/ui/parser/issues/issue-87086-colon-path-sep.stderr index 8f93661a62646..2050a16beb349 100644 --- a/src/test/ui/parser/issues/issue-87086-colon-path-sep.stderr +++ b/src/test/ui/parser/issues/issue-87086-colon-path-sep.stderr @@ -1,5 +1,5 @@ error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:13:12 + --> $DIR/issue-87086-colon-path-sep.rs:17:12 | LL | Foo:Bar => {} | ^ @@ -8,55 +8,61 @@ LL | Foo:Bar => {} | help: maybe write a path separator here: `::` error: expected one of `!`, `(`, `...`, `..=`, `..`, `::`, `{`, or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:19:17 + --> $DIR/issue-87086-colon-path-sep.rs:23:17 | -LL | Foo::Bar:Baz => {} +LL | qux::Foo:Bar => {} | ^ | | | expected one of 8 possible tokens | help: maybe write a path separator here: `::` error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:25:12 + --> $DIR/issue-87086-colon-path-sep.rs:29:12 | -LL | Foo:Bar::Baz => {} +LL | qux:Foo::Baz => {} | ^ | | | expected one of `@` or `|` | help: maybe write a path separator here: `::` error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:31:12 + --> $DIR/issue-87086-colon-path-sep.rs:35:12 | -LL | Foo: Bar::Baz if true => {} +LL | qux: Foo::Baz if true => {} | ^ | | | expected one of `@` or `|` | help: maybe write a path separator here: `::` error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:36:15 + --> $DIR/issue-87086-colon-path-sep.rs:40:15 | -LL | if let Bar:Baz = f() { +LL | if let Foo:Bar = f() { | ^ | | | expected one of `@` or `|` | help: maybe write a path separator here: `::` -error: expected one of `=>`, `@`, `if`, or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:44:16 +error: expected one of `@` or `|`, found `:` + --> $DIR/issue-87086-colon-path-sep.rs:48:16 | -LL | ref Foo: Bar::Baz => {} - | ^ expected one of `=>`, `@`, `if`, or `|` +LL | ref qux: Foo::Baz => {} + | ^ + | | + | expected one of `@` or `|` + | help: maybe write a path separator here: `::` -error: expected one of `=>`, `@`, `if`, or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:52:16 +error: expected one of `@` or `|`, found `:` + --> $DIR/issue-87086-colon-path-sep.rs:57:16 | -LL | mut Foo: Bar::Baz => {} - | ^ expected one of `=>`, `@`, `if`, or `|` +LL | mut qux: Foo::Baz => {} + | ^ + | | + | expected one of `@` or `|` + | help: maybe write a path separator here: `::` error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:62:12 + --> $DIR/issue-87086-colon-path-sep.rs:68:12 | LL | Foo:Bar::Baz => {} | ^ @@ -64,5 +70,21 @@ LL | Foo:Bar::Baz => {} | expected one of `@` or `|` | help: maybe write a path separator here: `::` -error: aborting due to 8 previous errors +error: expected one of `@` or `|`, found `:` + --> $DIR/issue-87086-colon-path-sep.rs:75:12 + | +LL | Foo:Bar => {} + | ^ + | | + | expected one of `@` or `|` + | help: maybe write a path separator here: `::` + +error[E0433]: failed to resolve: `Bar` is a variant, not a module + --> $DIR/issue-87086-colon-path-sep.rs:68:13 + | +LL | Foo:Bar::Baz => {} + | ^^^ `Bar` is a variant, not a module + +error: aborting due to 10 previous errors +For more information about this error, try `rustc --explain E0433`.