From 40dcf89a26bde41734f6c3eb71d9eb6420e45ef8 Mon Sep 17 00:00:00 2001
From: Takayuki Maeda <takoyaki0316@gmail.com>
Date: Mon, 15 Aug 2022 16:10:31 +0900
Subject: [PATCH] suggest adding a missing semicolon before an item
---
compiler/rustc_ast/src/token.rs | 24 ++++++
.../rustc_parse/src/parser/diagnostics.rs | 6 +-
.../recover-missing-semi-before-item.fixed | 61 ++++++++++++++
.../recover-missing-semi-before-item.rs | 61 ++++++++++++++
.../recover-missing-semi-before-item.stderr | 83 +++++++++++++++++++
5 files changed, 233 insertions(+), 2 deletions(-)
create mode 100644 src/test/ui/parser/recover-missing-semi-before-item.fixed
create mode 100644 src/test/ui/parser/recover-missing-semi-before-item.rs
create mode 100644 src/test/ui/parser/recover-missing-semi-before-item.stderr
diff --git a/compiler/rustc_ast/src/token.rs b/compiler/rustc_ast/src/token.rs
index 85d9687c600dc..dd98946b4cc5e 100644
--- a/compiler/rustc_ast/src/token.rs
+++ b/compiler/rustc_ast/src/token.rs
@@ -436,6 +436,30 @@ impl Token {
|| self == &OpenDelim(Delimiter::Parenthesis)
}
+ /// Returns `true` if the token can appear at the start of an item.
+ pub fn can_begin_item(&self) -> bool {
+ match self.kind {
+ Ident(name, _) => [
+ kw::Fn,
+ kw::Use,
+ kw::Struct,
+ kw::Enum,
+ kw::Pub,
+ kw::Trait,
+ kw::Extern,
+ kw::Impl,
+ kw::Unsafe,
+ kw::Static,
+ kw::Union,
+ kw::Macro,
+ kw::Mod,
+ kw::Type,
+ ]
+ .contains(&name),
+ _ => false,
+ }
+ }
+
/// Returns `true` if the token is any literal.
pub fn is_lit(&self) -> bool {
matches!(self.kind, Literal(..))
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index f4c6b33a52924..d0fb768caa687 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -555,10 +555,12 @@ impl<'a> Parser<'a> {
return Ok(true);
} else if self.look_ahead(0, |t| {
t == &token::CloseDelim(Delimiter::Brace)
- || (t.can_begin_expr() && t != &token::Semi && t != &token::Pound)
+ || ((t.can_begin_expr() || t.can_begin_item())
+ && t != &token::Semi
+ && t != &token::Pound)
// Avoid triggering with too many trailing `#` in raw string.
|| (sm.is_multiline(
- self.prev_token.span.shrink_to_hi().until(self.token.span.shrink_to_lo())
+ self.prev_token.span.shrink_to_hi().until(self.token.span.shrink_to_lo()),
) && t == &token::Pound)
}) && !expected.contains(&TokenType::Token(token::Comma))
{
diff --git a/src/test/ui/parser/recover-missing-semi-before-item.fixed b/src/test/ui/parser/recover-missing-semi-before-item.fixed
new file mode 100644
index 0000000000000..0be17e69e8ff7
--- /dev/null
+++ b/src/test/ui/parser/recover-missing-semi-before-item.fixed
@@ -0,0 +1,61 @@
+// run-rustfix
+
+#![allow(unused_variables, dead_code)]
+
+fn for_struct() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `struct`
+ struct Foo;
+}
+
+fn for_union() {
+ let foo = 3; //~ ERROR expected `;`, found `union`
+ union Foo {
+ foo: usize,
+ }
+}
+
+fn for_enum() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `enum`
+ enum Foo {
+ Bar,
+ }
+}
+
+fn for_fn() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `fn`
+ fn foo() {}
+}
+
+fn for_extern() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `extern`
+ extern fn foo() {}
+}
+
+fn for_impl() {
+ struct Foo;
+ let foo = 3; //~ ERROR expected `;`, found keyword `impl`
+ impl Foo {}
+}
+
+fn for_use() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `pub`
+ pub use bar::Bar;
+}
+
+fn for_mod() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `mod`
+ mod foo {}
+}
+
+fn for_type() {
+ let foo = 3; //~ ERROR expected `;`, found keyword `type`
+ type Foo = usize;
+}
+
+mod bar {
+ pub struct Bar;
+}
+
+const X: i32 = 123; //~ ERROR expected `;`, found keyword `fn`
+
+fn main() {}
diff --git a/src/test/ui/parser/recover-missing-semi-before-item.rs b/src/test/ui/parser/recover-missing-semi-before-item.rs
new file mode 100644
index 0000000000000..867b7b749bb1f
--- /dev/null
+++ b/src/test/ui/parser/recover-missing-semi-before-item.rs
@@ -0,0 +1,61 @@
+// run-rustfix
+
+#![allow(unused_variables, dead_code)]
+
+fn for_struct() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `struct`
+ struct Foo;
+}
+
+fn for_union() {
+ let foo = 3 //~ ERROR expected `;`, found `union`
+ union Foo {
+ foo: usize,
+ }
+}
+
+fn for_enum() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `enum`
+ enum Foo {
+ Bar,
+ }
+}
+
+fn for_fn() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `fn`
+ fn foo() {}
+}
+
+fn for_extern() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `extern`
+ extern fn foo() {}
+}
+
+fn for_impl() {
+ struct Foo;
+ let foo = 3 //~ ERROR expected `;`, found keyword `impl`
+ impl Foo {}
+}
+
+fn for_use() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `pub`
+ pub use bar::Bar;
+}
+
+fn for_mod() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `mod`
+ mod foo {}
+}
+
+fn for_type() {
+ let foo = 3 //~ ERROR expected `;`, found keyword `type`
+ type Foo = usize;
+}
+
+mod bar {
+ pub struct Bar;
+}
+
+const X: i32 = 123 //~ ERROR expected `;`, found keyword `fn`
+
+fn main() {}
diff --git a/src/test/ui/parser/recover-missing-semi-before-item.stderr b/src/test/ui/parser/recover-missing-semi-before-item.stderr
new file mode 100644
index 0000000000000..61c43f2f18998
--- /dev/null
+++ b/src/test/ui/parser/recover-missing-semi-before-item.stderr
@@ -0,0 +1,83 @@
+error: expected `;`, found keyword `struct`
+ --> $DIR/recover-missing-semi-before-item.rs:6:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | struct Foo;
+ | ------ unexpected token
+
+error: expected `;`, found `union`
+ --> $DIR/recover-missing-semi-before-item.rs:11:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | union Foo {
+ | ----- unexpected token
+
+error: expected `;`, found keyword `enum`
+ --> $DIR/recover-missing-semi-before-item.rs:18:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | enum Foo {
+ | ---- unexpected token
+
+error: expected `;`, found keyword `fn`
+ --> $DIR/recover-missing-semi-before-item.rs:25:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | fn foo() {}
+ | -- unexpected token
+
+error: expected `;`, found keyword `extern`
+ --> $DIR/recover-missing-semi-before-item.rs:30:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | extern fn foo() {}
+ | ------ unexpected token
+
+error: expected `;`, found keyword `impl`
+ --> $DIR/recover-missing-semi-before-item.rs:36:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | impl Foo {}
+ | ---- unexpected token
+
+error: expected `;`, found keyword `pub`
+ --> $DIR/recover-missing-semi-before-item.rs:41:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | pub use bar::Bar;
+ | --- unexpected token
+
+error: expected `;`, found keyword `mod`
+ --> $DIR/recover-missing-semi-before-item.rs:46:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | mod foo {}
+ | --- unexpected token
+
+error: expected `;`, found keyword `type`
+ --> $DIR/recover-missing-semi-before-item.rs:51:16
+ |
+LL | let foo = 3
+ | ^ help: add `;` here
+LL | type Foo = usize;
+ | ---- unexpected token
+
+error: expected `;`, found keyword `fn`
+ --> $DIR/recover-missing-semi-before-item.rs:59:19
+ |
+LL | const X: i32 = 123
+ | ^ help: add `;` here
+LL |
+LL | fn main() {}
+ | -- unexpected token
+
+error: aborting due to 10 previous errors
+