Revert "Don't recover lifetimes/labels containing emojis as character literals"

Reverts PR #108031 Fixes (doesnt close until beta backported) #109746 This reverts commit e3f9db5fc3. This reverts commit 98b82aedba. This reverts commit 380fa26413.
2024-11-26 00:34:06 +00:00 · 2023-04-10 06:52:18 +00:00 · 2023-04-10 06:52:18 +00:00 · a047064d6b
commit a047064d6b
parent 3c2e2dd5c5
8 changed files with 17 additions and 178 deletions
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@ -473,8 +473,6 @@ pub enum StashKey {
    /// When an invalid lifetime e.g. `'2` should be reinterpreted
    /// as a char literal in the parser
    LifetimeIsChar,
-    /// When an invalid lifetime e.g. `'🐱` contains emoji.
-    LifetimeContainsEmoji,
    /// Maybe there was a typo where a comma was forgotten before
    /// FRU syntax
    MaybeFruTypo,
--- a/compiler/rustc_lexer/src/lib.rs
+++ b/compiler/rustc_lexer/src/lib.rs
@ -95,7 +95,7 @@ pub enum TokenKind {
    Literal { kind: LiteralKind, suffix_start: u32 },

    /// "'a"
-    Lifetime { starts_with_number: bool, contains_emoji: bool },
+    Lifetime { starts_with_number: bool },

    // One-char tokens:
    /// ";"
@ -632,13 +632,7 @@ impl Cursor<'_> {
            // If the first symbol is valid for identifier, it can be a lifetime.
            // Also check if it's a number for a better error reporting (so '0 will
            // be reported as invalid lifetime and not as unterminated char literal).
-            // We also have to account for potential `'🐱` emojis to avoid reporting
-            // it as an unterminated char literal.
-            is_id_start(self.first())
-                || self.first().is_digit(10)
-                // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
-                // 5.0, but Unicode is already newer than this.
-                || unic_emoji_char::is_emoji(self.first())
+            is_id_start(self.first()) || self.first().is_digit(10)
        };

        if !can_be_a_lifetime {
@ -651,33 +645,16 @@ impl Cursor<'_> {
            return Literal { kind, suffix_start };
        }

-        // Either a lifetime or a character literal.
+        // Either a lifetime or a character literal with
+        // length greater than 1.

        let starts_with_number = self.first().is_digit(10);
-        let mut contains_emoji = false;

-        // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
-        // 5.0, but Unicode is already newer than this.
-        if unic_emoji_char::is_emoji(self.first()) {
-            contains_emoji = true;
-        } else {
        // Skip the literal contents.
        // First symbol can be a number (which isn't a valid identifier start),
        // so skip it without any checks.
        self.bump();
-        }
-        self.eat_while(|c| {
-            if is_id_continue(c) {
-                true
-            // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
-            // 5.0, but Unicode is already newer than this.
-            } else if unic_emoji_char::is_emoji(c) {
-                contains_emoji = true;
-                true
-            } else {
-                false
-            }
-        });
+        self.eat_while(is_id_continue);

        // Check if after skipping literal contents we've met a closing
        // single quote (which means that user attempted to create a
@ -687,7 +664,7 @@ impl Cursor<'_> {
            let kind = Char { terminated: true };
            Literal { kind, suffix_start: self.pos_within_token() }
        } else {
-            Lifetime { starts_with_number, contains_emoji }
+            Lifetime { starts_with_number }
        }
    }

--- a/compiler/rustc_lexer/src/tests.rs
+++ b/compiler/rustc_lexer/src/tests.rs
@ -235,7 +235,7 @@ fn lifetime() {
    check_lexing(
        "'abc",
        expect![[r#"
-            Token { kind: Lifetime { starts_with_number: false, contains_emoji: false }, len: 4 }
+            Token { kind: Lifetime { starts_with_number: false }, len: 4 }
        "#]],
    );
 }
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@ -223,21 +223,16 @@ impl<'a> StringReader<'a> {
                    };
                    token::Literal(token::Lit { kind, symbol, suffix })
                }
-                rustc_lexer::TokenKind::Lifetime { starts_with_number, contains_emoji } => {
+                rustc_lexer::TokenKind::Lifetime { starts_with_number } => {
                    // Include the leading `'` in the real identifier, for macro
                    // expansion purposes. See #12512 for the gory details of why
                    // this is necessary.
                    let lifetime_name = self.str_from(start);
                    if starts_with_number {
                        let span = self.mk_sp(start, self.pos);
-                        let mut diag = self.sess.struct_err("lifetimes or labels cannot start with a number");
+                        let mut diag = self.sess.struct_err("lifetimes cannot start with a number");
                        diag.set_span(span);
                        diag.stash(span, StashKey::LifetimeIsChar);
-                    } else if contains_emoji {
-                        let span = self.mk_sp(start, self.pos);
-                        let mut diag = self.sess.struct_err("lifetimes or labels cannot contain emojis");
-                        diag.set_span(span);
-                        diag.stash(span, StashKey::LifetimeContainsEmoji);
                    }
                    let ident = Symbol::intern(lifetime_name);
                    token::Lifetime(ident)
--- a/tests/ui/lexer/issue-108019-bad-emoji-recovery.rs
+++ b/tests/ui/lexer/issue-108019-bad-emoji-recovery.rs
@ -1,45 +0,0 @@
-#![allow(unused_labels)]
-
-// FIXME(#108019): outdated Unicode table
-// fn foo() {
-//     '🥺 loop {
-//         break
-//     }
-// }
-
-fn bar() {
-    '🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot contain emojis
-        break
-    }
-}
-
-fn qux() {
-    'a🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot contain emojis
-        break
-    }
-}
-
-fn quux() {
-    '1🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot start with a number
-        break
-    }
-}
-
-fn x<'🐱>() -> &'🐱 () {
-    //~^ ERROR lifetimes or labels cannot contain emojis
-    //~| ERROR lifetimes or labels cannot contain emojis
-    &()
-}
-
-fn y() {
-    'a🐱: loop {}
-    //~^ ERROR lifetimes or labels cannot contain emojis
-}
-
-fn main() {}
--- a/tests/ui/lexer/issue-108019-bad-emoji-recovery.stderr
+++ b/tests/ui/lexer/issue-108019-bad-emoji-recovery.stderr
@ -1,86 +0,0 @@
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:11:5
-   |
-LL |       '🐱 loop {
-   |       ^--- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:19:5
-   |
-LL |       'a🐱 loop {
-   |       ^---- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:27:5
-   |
-LL |       '1🐱 loop {
-   |       ^---- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:11:5
-   |
-LL |     '🐱 loop {
-   |     ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:19:5
-   |
-LL |     'a🐱 loop {
-   |     ^^^^
-
-error: lifetimes or labels cannot start with a number
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:27:5
-   |
-LL |     '1🐱 loop {
-   |     ^^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:34:6
-   |
-LL | fn x<'🐱>() -> &'🐱 () {
-   |      ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:34:16
-   |
-LL | fn x<'🐱>() -> &'🐱 () {
-   |                 ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:41:5
-   |
-LL |     'a🐱: loop {}
-   |     ^^^^
-
-error: aborting due to 9 previous errors
-
--- a/tests/ui/parser/numeric-lifetime.rs
+++ b/tests/ui/parser/numeric-lifetime.rs
@ -1,6 +1,6 @@
 struct S<'1> { s: &'1 usize }
-//~^ ERROR lifetimes or labels cannot start with a number
-//~| ERROR lifetimes or labels cannot start with a number
+//~^ ERROR lifetimes cannot start with a number
+//~| ERROR lifetimes cannot start with a number
 fn main() {
    // verify that the parse error doesn't stop type checking
    let x: usize = "";
--- a/tests/ui/parser/numeric-lifetime.stderr
+++ b/tests/ui/parser/numeric-lifetime.stderr
@ -6,13 +6,13 @@ LL |     let x: usize = "";
   |            |
   |            expected due to this

-error: lifetimes or labels cannot start with a number
+error: lifetimes cannot start with a number
  --> $DIR/numeric-lifetime.rs:1:10
   |
 LL | struct S<'1> { s: &'1 usize }
   |          ^^

-error: lifetimes or labels cannot start with a number
+error: lifetimes cannot start with a number
  --> $DIR/numeric-lifetime.rs:1:20
   |
 LL | struct S<'1> { s: &'1 usize }