bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Syntactically permit unsafety on mods

Browse source
This commit is contained in:
David Tolnay 2020-08-23 03:42:19 -07:00
parent 25b2f48612
commit fd4dd00dde
No known key found for this signature in database
GPG key ID: F9BA143B95FF6D82
17 changed files with 284 additions and 37 deletions
Download patch file Download diff file Expand all files Collapse all files

67
compiler/rustc_parse/src/parser/item.rs
View file

@ -28,7 +28,7 @@ impl<'a> Parser<'a> {
/// Parses a source module as a crate. This is the main entry point for the parser.
pub fn parse_crate_mod(&mut self) -> PResult<'a, ast::Crate> {
let lo = self.token.span;
let (module, attrs) = self.parse_mod(&token::Eof)?;
let (module, attrs) = self.parse_mod(&token::Eof, Unsafe::No)?;
let span = lo.to(self.token.span);
let proc_macros = Vec::new(); // Filled in by `proc_macro_harness::inject()`.
Ok(ast::Crate { attrs, module, span, proc_macros })
@ -36,27 +36,38 @@ impl<'a> Parser<'a> {
/// Parses a `mod <foo> { ... }` or `mod <foo>;` item.
fn parse_item_mod(&mut self, attrs: &mut Vec<Attribute>) -> PResult<'a, ItemInfo> {
let unsafety = self.parse_unsafety();
self.expect_keyword(kw::Mod)?;
let id = self.parse_ident()?;
let (module, mut inner_attrs) = if self.eat(&token::Semi) {
Default::default()
(Mod { inner: Span::default(), unsafety, items: Vec::new(), inline: false }, Vec::new())
} else {
self.expect(&token::OpenDelim(token::Brace))?;
self.parse_mod(&token::CloseDelim(token::Brace))?
self.parse_mod(&token::CloseDelim(token::Brace), unsafety)?
};
attrs.append(&mut inner_attrs);
Ok((id, ItemKind::Mod(module)))
}
/// Parses the contents of a module (inner attributes followed by module items).
pub fn parse_mod(&mut self, term: &TokenKind) -> PResult<'a, (Mod, Vec<Attribute>)> {
pub fn parse_mod(
&mut self,
term: &TokenKind,
unsafety: Unsafe,
) -> PResult<'a, (Mod, Vec<Attribute>)> {
let lo = self.token.span;
let attrs = self.parse_inner_attributes()?;
let module = self.parse_mod_items(term, lo)?;
let module = self.parse_mod_items(term, lo, unsafety)?;
Ok((module, attrs))
}
/// Given a termination token, parses all of the items in a module.
fn parse_mod_items(&mut self, term: &TokenKind, inner_lo: Span) -> PResult<'a, Mod> {
fn parse_mod_items(
&mut self,
term: &TokenKind,
inner_lo: Span,
unsafety: Unsafe,
) -> PResult<'a, Mod> {
let mut items = vec![];
while let Some(item) = self.parse_item()? {
items.push(item);
@ -75,7 +86,7 @@ impl<'a> Parser<'a> {
let hi = if self.token.span.is_dummy() { inner_lo } else { self.prev_token.span };
Ok(Mod { inner: inner_lo.to(hi), items, inline: true })
Ok(Mod { inner: inner_lo.to(hi), unsafety, items, inline: true })
}
}
@ -235,8 +246,13 @@ impl<'a> Parser<'a> {
self.parse_item_extern_crate()?
} else {
// EXTERN BLOCK
self.parse_item_foreign_mod(attrs)?
self.parse_item_foreign_mod(attrs, Unsafe::No)?
}
} else if self.is_unsafe_foreign_mod() {
// EXTERN BLOCK
let unsafety = self.parse_unsafety();
self.expect_keyword(kw::Extern)?;
self.parse_item_foreign_mod(attrs, unsafety)?
} else if self.is_static_global() {
// STATIC ITEM
self.bump(); // `static`
@ -256,7 +272,9 @@ impl<'a> Parser<'a> {
{
// IMPL ITEM
self.parse_item_impl(attrs, def())?
} else if self.eat_keyword(kw::Mod) {
} else if self.check_keyword(kw::Mod)
|| self.check_keyword(kw::Unsafe) && self.is_keyword_ahead(1, &[kw::Mod])
{
// MODULE ITEM
self.parse_item_mod(attrs)?
} else if self.eat_keyword(kw::Type) {
@ -893,10 +911,14 @@ impl<'a> Parser<'a> {
/// extern "C" {}
/// extern {}
/// ```
fn parse_item_foreign_mod(&mut self, attrs: &mut Vec<Attribute>) -> PResult<'a, ItemInfo> {
fn parse_item_foreign_mod(
&mut self,
attrs: &mut Vec<Attribute>,
unsafety: Unsafe,
) -> PResult<'a, ItemInfo> {
let abi = self.parse_abi(); // ABI?
let items = self.parse_item_list(attrs, |p| p.parse_foreign_item())?;
let module = ast::ForeignMod { abi, items };
let module = ast::ForeignMod { unsafety, abi, items };
Ok((Ident::invalid(), ItemKind::ForeignMod(module)))
}
@ -938,6 +960,15 @@ impl<'a> Parser<'a> {
.emit();
}
fn is_unsafe_foreign_mod(&self) -> bool {
self.token.is_keyword(kw::Unsafe)
&& self.is_keyword_ahead(1, &[kw::Extern])
&& self.look_ahead(
2 + self.look_ahead(2, |t| t.can_begin_literal_maybe_minus() as usize),
|t| t.kind == token::OpenDelim(token::Brace),
)
}
fn is_static_global(&mut self) -> bool {
if self.check_keyword(kw::Static) {
// Check if this could be a closure.
@ -1552,10 +1583,14 @@ impl<'a> Parser<'a> {
// `$qual fn` or `$qual $qual`:
|| QUALS.iter().any(|&kw| self.check_keyword(kw))
&& self.look_ahead(1, |t| {
// ...qualified and then `fn`, e.g. `const fn`.
// `$qual fn`, e.g. `const fn` or `async fn`.
t.is_keyword(kw::Fn)
// Two qualifiers. This is enough. Due `async` we need to check that it's reserved.
|| t.is_non_raw_ident_where(|i| QUALS.contains(&i.name) && i.is_reserved())
// Two qualifiers `$qual $qual` is enough, e.g. `async unsafe`.
|| t.is_non_raw_ident_where(|i| QUALS.contains(&i.name)
// Rule out 2015 `const async: T = val`.
&& i.is_reserved()
// Rule out unsafe extern block.
&& !self.is_unsafe_foreign_mod())
})
// `extern ABI fn`
|| self.check_keyword(kw::Extern)
@ -1567,9 +1602,9 @@ impl<'a> Parser<'a> {
/// up to and including the `fn` keyword. The formal grammar is:
///
/// ```
/// Extern = "extern" StringLit ;
/// Extern = "extern" StringLit? ;
/// FnQual = "const"? "async"? "unsafe"? Extern? ;
/// FnFrontMatter = FnQual? "fn" ;
/// FnFrontMatter = FnQual "fn" ;
/// ```
pub(super) fn parse_fn_front_matter(&mut self) -> PResult<'a, FnHeader> {
let constness = self.parse_constness();