diff options
| -rw-r--r-- | compiler/rustc_parse_format/src/lib.rs | 29 | ||||
| -rw-r--r-- | tests/ui/fmt/format-string-wrong-order.rs | 15 | ||||
| -rw-r--r-- | tests/ui/fmt/format-string-wrong-order.stderr | 54 |
3 files changed, 97 insertions, 1 deletions
diff --git a/compiler/rustc_parse_format/src/lib.rs b/compiler/rustc_parse_format/src/lib.rs index a6dfcd29762..088a87ca571 100644 --- a/compiler/rustc_parse_format/src/lib.rs +++ b/compiler/rustc_parse_format/src/lib.rs @@ -273,7 +273,13 @@ impl<'a> Iterator for Parser<'a> { ); } } else { - self.suggest_positional_arg_instead_of_captured_arg(arg); + if let Some(&(_, maybe)) = self.cur.peek() { + if maybe == '?' { + self.suggest_format(); + } else { + self.suggest_positional_arg_instead_of_captured_arg(arg); + } + } } Some(NextArgument(Box::new(arg))) } @@ -832,6 +838,27 @@ impl<'a> Parser<'a> { if found { Some(cur) } else { None } } + fn suggest_format(&mut self) { + if let (Some(pos), Some(_)) = (self.consume_pos('?'), self.consume_pos(':')) { + let word = self.word(); + let _end = self.current_pos(); + let pos = self.to_span_index(pos); + self.errors.insert( + 0, + ParseError { + description: "expected format parameter to occur after `:`".to_owned(), + note: Some( + format!("`?` comes after `:`, try `{}:{}` instead", word, "?").to_owned(), + ), + label: "expected `?` to occur after `:`".to_owned(), + span: pos.to(pos), + secondary_label: None, + should_be_replaced_with_positional_argument: false, + }, + ); + } + } + fn suggest_positional_arg_instead_of_captured_arg(&mut self, arg: Argument<'a>) { if let Some(end) = self.consume_pos('.') { let byte_pos = self.to_span_index(end); diff --git a/tests/ui/fmt/format-string-wrong-order.rs b/tests/ui/fmt/format-string-wrong-order.rs new file mode 100644 index 00000000000..0bad5402396 --- /dev/null +++ b/tests/ui/fmt/format-string-wrong-order.rs @@ -0,0 +1,15 @@ +fn main() { + let bar = 3; + format!("{?:}", bar); + //~^ ERROR invalid format string: expected format parameter to occur after `:` + format!("{?:bar}"); + //~^ ERROR invalid format string: expected format parameter to occur after `:` + format!("{?:?}", bar); + //~^ ERROR invalid format string: expected format parameter to occur after `:` + format!("{??}", bar); + //~^ ERROR invalid format string: expected `'}'`, found `'?'` + format!("{?;bar}"); + //~^ ERROR invalid format string: expected `'}'`, found `'?'` + format!("{?:#?}", bar); + //~^ ERROR invalid format string: expected format parameter to occur after `:` +} diff --git a/tests/ui/fmt/format-string-wrong-order.stderr b/tests/ui/fmt/format-string-wrong-order.stderr new file mode 100644 index 00000000000..461af354a4e --- /dev/null +++ b/tests/ui/fmt/format-string-wrong-order.stderr @@ -0,0 +1,54 @@ +error: invalid format string: expected format parameter to occur after `:` + --> $DIR/format-string-wrong-order.rs:3:15 + | +LL | format!("{?:}", bar); + | ^ expected `?` to occur after `:` in format string + | + = note: `?` comes after `:`, try `:?` instead + +error: invalid format string: expected format parameter to occur after `:` + --> $DIR/format-string-wrong-order.rs:5:15 + | +LL | format!("{?:bar}"); + | ^ expected `?` to occur after `:` in format string + | + = note: `?` comes after `:`, try `bar:?` instead + +error: invalid format string: expected format parameter to occur after `:` + --> $DIR/format-string-wrong-order.rs:7:15 + | +LL | format!("{?:?}", bar); + | ^ expected `?` to occur after `:` in format string + | + = note: `?` comes after `:`, try `:?` instead + +error: invalid format string: expected `'}'`, found `'?'` + --> $DIR/format-string-wrong-order.rs:9:15 + | +LL | format!("{??}", bar); + | -^ expected `}` in format string + | | + | because of this opening brace + | + = note: if you intended to print `{`, you can escape it using `{{` + +error: invalid format string: expected `'}'`, found `'?'` + --> $DIR/format-string-wrong-order.rs:11:15 + | +LL | format!("{?;bar}"); + | -^ expected `}` in format string + | | + | because of this opening brace + | + = note: if you intended to print `{`, you can escape it using `{{` + +error: invalid format string: expected format parameter to occur after `:` + --> $DIR/format-string-wrong-order.rs:13:15 + | +LL | format!("{?:#?}", bar); + | ^ expected `?` to occur after `:` in format string + | + = note: `?` comes after `:`, try `:?` instead + +error: aborting due to 6 previous errors + |