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`.