diff options
| -rw-r--r-- | src/librustc_parse/parser/item.rs | 17 | ||||
| -rw-r--r-- | src/test/ui/parser/fn-body-eq-expr-semi.rs | 23 | ||||
| -rw-r--r-- | src/test/ui/parser/fn-body-eq-expr-semi.stderr | 117 |
3 files changed, 156 insertions, 1 deletions
diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs index 428c01a8344..8263bd879ad 100644 --- a/src/librustc_parse/parser/item.rs +++ b/src/librustc_parse/parser/item.rs @@ -1412,10 +1412,25 @@ impl<'a> Parser<'a> { /// or e.g. a block when the function is a provided one. fn parse_fn_body(&mut self, attrs: &mut Vec<Attribute>) -> PResult<'a, Option<P<Block>>> { let (inner_attrs, body) = if self.check(&token::Semi) { - self.bump(); + self.bump(); // `;` (Vec::new(), None) } else if self.check(&token::OpenDelim(token::Brace)) || self.token.is_whole_block() { self.parse_inner_attrs_and_block().map(|(attrs, body)| (attrs, Some(body)))? + } else if self.token.kind == token::Eq { + // Recover `fn foo() = $expr;`. + self.bump(); // `=` + let eq_sp = self.prev_token.span; + let _ = self.parse_expr()?; + self.expect_semi()?; // `;` + let span = eq_sp.to(self.prev_token.span); + self.struct_span_err(span, "function body cannot be `= expression;`") + .multipart_suggestion( + "surround the expression with `{` and `}` instead of `=` and `;`", + vec![(eq_sp, "{".to_string()), (self.prev_token.span, " }".to_string())], + Applicability::MachineApplicable, + ) + .emit(); + (Vec::new(), Some(self.mk_block_err(span))) } else { return self.expected_semi_or_open_brace(); }; diff --git a/src/test/ui/parser/fn-body-eq-expr-semi.rs b/src/test/ui/parser/fn-body-eq-expr-semi.rs new file mode 100644 index 00000000000..09444079365 --- /dev/null +++ b/src/test/ui/parser/fn-body-eq-expr-semi.rs @@ -0,0 +1,23 @@ +fn main() {} + +fn syntax() { + fn foo() = 42; //~ ERROR function body cannot be `= expression;` + fn bar() -> u8 = 42; //~ ERROR function body cannot be `= expression;` +} + +extern { + fn foo() = 42; //~ ERROR function body cannot be `= expression;` + //~^ ERROR incorrect function inside `extern` block + fn bar() -> u8 = 42; //~ ERROR function body cannot be `= expression;` + //~^ ERROR incorrect function inside `extern` block +} + +trait Foo { + fn foo() = 42; //~ ERROR function body cannot be `= expression;` + fn bar() -> u8 = 42; //~ ERROR function body cannot be `= expression;` +} + +impl Foo for () { + fn foo() = 42; //~ ERROR function body cannot be `= expression;` + fn bar() -> u8 = 42; //~ ERROR function body cannot be `= expression;` +} diff --git a/src/test/ui/parser/fn-body-eq-expr-semi.stderr b/src/test/ui/parser/fn-body-eq-expr-semi.stderr new file mode 100644 index 00000000000..739133e0b40 --- /dev/null +++ b/src/test/ui/parser/fn-body-eq-expr-semi.stderr @@ -0,0 +1,117 @@ +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:4:14 + | +LL | fn foo() = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn foo() { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:5:20 + | +LL | fn bar() -> u8 = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn bar() -> u8 { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:9:14 + | +LL | fn foo() = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn foo() { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:11:20 + | +LL | fn bar() -> u8 = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn bar() -> u8 { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:16:14 + | +LL | fn foo() = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn foo() { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:17:20 + | +LL | fn bar() -> u8 = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn bar() -> u8 { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:21:14 + | +LL | fn foo() = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn foo() { 42 } + | ^ ^ + +error: function body cannot be `= expression;` + --> $DIR/fn-body-eq-expr-semi.rs:22:20 + | +LL | fn bar() -> u8 = 42; + | ^^^^^ + | +help: surround the expression with `{` and `}` instead of `=` and `;` + | +LL | fn bar() -> u8 { 42 } + | ^ ^ + +error: incorrect function inside `extern` block + --> $DIR/fn-body-eq-expr-semi.rs:9:8 + | +LL | extern { + | ------ `extern` blocks define existing foreign functions and functions inside of them cannot have a body +LL | fn foo() = 42; + | ^^^ ----- help: remove the invalid body: `;` + | | + | cannot have a body + | + = help: you might have meant to write a function accessible through FFI, which can be done by writing `extern fn` outside of the `extern` block + = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html + +error: incorrect function inside `extern` block + --> $DIR/fn-body-eq-expr-semi.rs:11:8 + | +LL | extern { + | ------ `extern` blocks define existing foreign functions and functions inside of them cannot have a body +... +LL | fn bar() -> u8 = 42; + | ^^^ ----- help: remove the invalid body: `;` + | | + | cannot have a body + | + = help: you might have meant to write a function accessible through FFI, which can be done by writing `extern fn` outside of the `extern` block + = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html + +error: aborting due to 10 previous errors + |