From 769b95dc9f92edb51146727813ea7eae00b5b651 Mon Sep 17 00:00:00 2001 From: Esteban Küber Date: Fri, 17 Mar 2017 21:13:00 -0700 Subject: Add diagnostic for incorrect `pub (restriction)` Given the following statement ```rust pub (a) fn afn() {} ``` Provide the following diagnostic: ```rust error: incorrect restriction in `pub` --> file.rs:15:1 | 15 | pub (a) fn afn() {} | ^^^^^^^ | = help: some valid visibility restrictions are: `pub(crate)`: visible only on the current crate `pub(super)`: visible only in the current module's parent `pub(in path::to::module)`: visible only on the specified path help: to make this visible only to module `a`, add `in` before the path: | pub (in a) fn afn() {} ``` Remove cruft from old `pub(path)` syntax. --- src/libsyntax/parse/parser.rs | 64 +++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 26 deletions(-) (limited to 'src/libsyntax/parse/parser.rs') diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index df4ccc94c04..649e9059934 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -4626,7 +4626,7 @@ impl<'a> Parser<'a> { let mut attrs = self.parse_outer_attributes()?; let lo = self.span.lo; - let vis = self.parse_visibility()?; + let vis = self.parse_visibility(false)?; let defaultness = self.parse_defaultness()?; let (name, node) = if self.eat_keyword(keywords::Type) { let name = self.parse_ident()?; @@ -4939,25 +4939,8 @@ impl<'a> Parser<'a> { |p| { let attrs = p.parse_outer_attributes()?; let lo = p.span.lo; - let mut vis = p.parse_visibility()?; - let ty_is_interpolated = - p.token.is_interpolated() || p.look_ahead(1, |t| t.is_interpolated()); - let mut ty = p.parse_ty()?; - - // Handle `pub(path) type`, in which `vis` will be `pub` and `ty` will be `(path)`. - if vis == Visibility::Public && !ty_is_interpolated && - p.token != token::Comma && p.token != token::CloseDelim(token::Paren) { - ty = if let TyKind::Paren(ref path_ty) = ty.node { - if let TyKind::Path(None, ref path) = path_ty.node { - vis = Visibility::Restricted { path: P(path.clone()), id: path_ty.id }; - Some(p.parse_ty()?) - } else { - None - } - } else { - None - }.unwrap_or(ty); - } + let vis = p.parse_visibility(true)?; + let ty = p.parse_ty()?; Ok(StructField { span: mk_sp(lo, p.span.hi), vis: vis, @@ -4996,18 +4979,25 @@ impl<'a> Parser<'a> { fn parse_struct_decl_field(&mut self) -> PResult<'a, StructField> { let attrs = self.parse_outer_attributes()?; let lo = self.span.lo; - let vis = self.parse_visibility()?; + let vis = self.parse_visibility(false)?; self.parse_single_struct_field(lo, vis, attrs) } - // Parse `pub`, `pub(crate)` and `pub(in path)` plus shortcuts - // `pub(self)` for `pub(in self)` and `pub(super)` for `pub(in super)`. - fn parse_visibility(&mut self) -> PResult<'a, Visibility> { + /// Parse `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `pub(self)` for `pub(in self)` + /// and `pub(super)` for `pub(in super)`. If the following element can't be a tuple (i.e. it's + /// a function definition, it's not a tuple struct field) and the contents within the parens + /// isn't valid, emit a proper diagnostic. + fn parse_visibility(&mut self, can_take_tuple: bool) -> PResult<'a, Visibility> { if !self.eat_keyword(keywords::Pub) { return Ok(Visibility::Inherited) } if self.check(&token::OpenDelim(token::Paren)) { + let start_span = self.span; + // We don't `self.bump()` the `(` yet because this might be a struct definition where + // `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`. + // Because of this, we only `bump` the `(` if we're assured it is appropriate to do so + // by the following tokens. if self.look_ahead(1, |t| t.is_keyword(keywords::Crate)) { // `pub(crate)` self.bump(); // `(` @@ -5032,6 +5022,28 @@ impl<'a> Parser<'a> { let vis = Visibility::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; self.expect(&token::CloseDelim(token::Paren))?; // `)` return Ok(vis) + } else if !can_take_tuple { // Provide this diagnostic if this is not a tuple struct + // `pub(something) fn ...` or `struct X { pub(something) y: Z }` + self.bump(); // `(` + let msg = "incorrect visibility restriction"; + let suggestion = r##"some possible visibility restrictions are: +`pub(crate)`: visible only on the current crate +`pub(super)`: visible only in the current module's parent +`pub(in path::to::module)`: visible only on the specified path"##; + let path = self.parse_path(PathStyle::Mod)?; + let path_span = self.prev_span; + let help_msg = format!("to make this visible only to module `{}`, add `in` before \ + the path:", + path); + self.expect(&token::CloseDelim(token::Paren))?; // `)` + let sp = Span { + lo: start_span.lo, + hi: self.prev_span.hi, + expn_id: start_span.expn_id, + }; + let mut err = self.span_fatal_help(sp, &msg, &suggestion); + err.span_suggestion(path_span, &help_msg, format!("in {}", path)); + err.emit(); // emit diagnostic, but continue with public visibility } } @@ -5508,7 +5520,7 @@ impl<'a> Parser<'a> { let lo = self.span.lo; - let visibility = self.parse_visibility()?; + let visibility = self.parse_visibility(false)?; if self.eat_keyword(keywords::Use) { // USE ITEM @@ -5787,7 +5799,7 @@ impl<'a> Parser<'a> { fn parse_foreign_item(&mut self) -> PResult<'a, Option> { let attrs = self.parse_outer_attributes()?; let lo = self.span.lo; - let visibility = self.parse_visibility()?; + let visibility = self.parse_visibility(false)?; if self.check_keyword(keywords::Static) { // FOREIGN STATIC ITEM -- cgit 1.4.1-3-g733a5