diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs index db5b8dcda4eab..01e3b29290318 100644 --- a/src/libsyntax/parse/lexer/mod.rs +++ b/src/libsyntax/parse/lexer/mod.rs @@ -1423,15 +1423,17 @@ impl<'a> StringReader<'a> { // If the character is an ident start not followed by another single // quote, then this is a lifetime name: - if ident_start(Some(c2)) && !self.ch_is('\'') { + if (ident_start(Some(c2)) || c2.is_numeric()) && !self.ch_is('\'') { while ident_continue(self.ch) { self.bump(); } // lifetimes shouldn't end with a single quote // if we find one, then this is an invalid character literal if self.ch_is('\'') { - self.err_span_(start_with_quote, self.next_pos, - "character literal may only contain one codepoint"); + self.err_span_( + start_with_quote, + self.next_pos, + "character literal may only contain one codepoint"); self.bump(); return Ok(token::Literal(token::Err(Symbol::intern("??")), None)) @@ -1444,6 +1446,15 @@ impl<'a> StringReader<'a> { self.mk_ident(&format!("'{}", lifetime_name)) }); + if c2.is_numeric() { + // this is a recovered lifetime written `'1`, error but accept it + self.err_span_( + start_with_quote, + self.pos, + "lifetimes cannot start with a number", + ); + } + return Ok(token::Lifetime(ident)); } @@ -1873,6 +1884,7 @@ fn is_block_doc_comment(s: &str) -> bool { res } +/// Determine whether `c` is a valid start for an ident. fn ident_start(c: Option) -> bool { let c = match c { Some(c) => c, diff --git a/src/test/ui/parser/numeric-lifetime.rs b/src/test/ui/parser/numeric-lifetime.rs new file mode 100644 index 0000000000000..2d82354c62cca --- /dev/null +++ b/src/test/ui/parser/numeric-lifetime.rs @@ -0,0 +1,8 @@ +struct S<'1> { s: &'1 usize } +//~^ 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 = ""; + //~^ ERROR mismatched types +} diff --git a/src/test/ui/parser/numeric-lifetime.stderr b/src/test/ui/parser/numeric-lifetime.stderr new file mode 100644 index 0000000000000..4018b24aac175 --- /dev/null +++ b/src/test/ui/parser/numeric-lifetime.stderr @@ -0,0 +1,24 @@ +error: lifetimes cannot start with a number + --> $DIR/numeric-lifetime.rs:1:10 + | +LL | struct S<'1> { s: &'1 usize } + | ^^ + +error: lifetimes cannot start with a number + --> $DIR/numeric-lifetime.rs:1:20 + | +LL | struct S<'1> { s: &'1 usize } + | ^^ + +error[E0308]: mismatched types + --> $DIR/numeric-lifetime.rs:6:20 + | +LL | let x: usize = ""; + | ^^ expected usize, found reference + | + = note: expected type `usize` + found type `&'static str` + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0308`.