use std::fmt;
/// A SyntaxContext represents a chain of macro expansions (represented by marks).
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Clone, Copy, PartialEq, Eq, Default, PartialOrd, Ord, Hash)]
pub struct SyntaxContext(u32);
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Default)]
pub struct SyntaxContextData {
pub outer_mark: Mark,
pub prev_ctxt: SyntaxContext,
+ pub modern: SyntaxContext,
}
/// A mark is a unique id associated with a macro expansion.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Default, RustcEncodable, RustcDecodable)]
pub struct Mark(u32);
+#[derive(Default)]
+struct MarkData {
+ parent: Mark,
+ modern: bool,
+ expn_info: Option<ExpnInfo>,
+}
+
impl Mark {
- pub fn fresh() -> Self {
+ pub fn fresh(parent: Mark) -> Self {
HygieneData::with(|data| {
- data.marks.push(None);
+ data.marks.push(MarkData { parent: parent, modern: false, expn_info: None });
Mark(data.marks.len() as u32 - 1)
})
}
}
pub fn expn_info(self) -> Option<ExpnInfo> {
- HygieneData::with(|data| data.marks[self.0 as usize].clone())
+ HygieneData::with(|data| data.marks[self.0 as usize].expn_info.clone())
}
pub fn set_expn_info(self, info: ExpnInfo) {
- HygieneData::with(|data| data.marks[self.0 as usize] = Some(info))
+ HygieneData::with(|data| data.marks[self.0 as usize].expn_info = Some(info))
+ }
+
+ pub fn modern(mut self) -> Mark {
+ HygieneData::with(|data| {
+ loop {
+ if self == Mark::root() || data.marks[self.0 as usize].modern {
+ return self;
+ }
+ self = data.marks[self.0 as usize].parent;
+ }
+ })
+ }
+
+ pub fn set_modern(self) {
+ HygieneData::with(|data| data.marks[self.0 as usize].modern = true)
+ }
+
+ pub fn is_descendant_of(mut self, ancestor: Mark) -> bool {
+ HygieneData::with(|data| {
+ while self != ancestor {
+ if self == Mark::root() {
+ return false;
+ }
+ self = data.marks[self.0 as usize].parent;
+ }
+ true
+ })
}
}
struct HygieneData {
- marks: Vec<Option<ExpnInfo>>,
+ marks: Vec<MarkData>,
syntax_contexts: Vec<SyntaxContextData>,
markings: HashMap<(SyntaxContext, Mark), SyntaxContext>,
}
impl HygieneData {
fn new() -> Self {
HygieneData {
- marks: vec![None],
- syntax_contexts: vec![SyntaxContextData {
- outer_mark: Mark::root(),
- prev_ctxt: SyntaxContext::empty(),
- }],
+ marks: vec![MarkData::default()],
+ syntax_contexts: vec![SyntaxContextData::default()],
markings: HashMap::new(),
}
}
SyntaxContext(0)
}
- pub fn data(self) -> SyntaxContextData {
- HygieneData::with(|data| data.syntax_contexts[self.0 as usize])
- }
-
/// Extend a syntax context with a given mark
pub fn apply_mark(self, mark: Mark) -> SyntaxContext {
- // Applying the same mark twice is a no-op
- let ctxt_data = self.data();
- if mark == ctxt_data.outer_mark {
- return ctxt_data.prev_ctxt;
- }
-
HygieneData::with(|data| {
let syntax_contexts = &mut data.syntax_contexts;
+ let ctxt_data = syntax_contexts[self.0 as usize];
+ if mark == ctxt_data.outer_mark {
+ return ctxt_data.prev_ctxt;
+ }
+
+ let modern = if data.marks[mark.0 as usize].modern {
+ *data.markings.entry((ctxt_data.modern, mark)).or_insert_with(|| {
+ let modern = SyntaxContext(syntax_contexts.len() as u32);
+ syntax_contexts.push(SyntaxContextData {
+ outer_mark: mark,
+ prev_ctxt: ctxt_data.modern,
+ modern: modern,
+ });
+ modern
+ })
+ } else {
+ ctxt_data.modern
+ };
+
*data.markings.entry((self, mark)).or_insert_with(|| {
syntax_contexts.push(SyntaxContextData {
outer_mark: mark,
prev_ctxt: self,
+ modern: modern,
});
SyntaxContext(syntax_contexts.len() as u32 - 1)
})
})
}
+ pub fn remove_mark(&mut self) -> Mark {
+ HygieneData::with(|data| {
+ let outer_mark = data.syntax_contexts[self.0 as usize].outer_mark;
+ *self = data.syntax_contexts[self.0 as usize].prev_ctxt;
+ outer_mark
+ })
+ }
+
+ /// Adjust this context for resolution in a scope created by the given expansion.
+ /// For example, consider the following three resolutions of `f`:
+ /// ```rust
+ /// mod foo { pub fn f() {} } // `f`'s `SyntaxContext` is empty.
+ /// m!(f);
+ /// macro m($f:ident) {
+ /// mod bar {
+ /// pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
+ /// pub fn $f() {} // `$f`'s `SyntaxContext` is empty.
+ /// }
+ /// foo::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
+ /// //^ Since `mod foo` is outside this expansion, `adjust` removes the mark from `f`,
+ /// //| and it resolves to `::foo::f`.
+ /// bar::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
+ /// //^ Since `mod bar` not outside this expansion, `adjust` does not change `f`,
+ /// //| and it resolves to `::bar::f`.
+ /// bar::$f(); // `f`'s `SyntaxContext` is empty.
+ /// //^ Since `mod bar` is not outside this expansion, `adjust` does not change `$f`,
+ /// //| and it resolves to `::bar::$f`.
+ /// }
+ /// ```
+ /// This returns the expansion whose definition scope we use to privacy check the resolution,
+ /// or `None` if we privacy check as usual (i.e. not w.r.t. a macro definition scope).
+ pub fn adjust(&mut self, expansion: Mark) -> Option<Mark> {
+ let mut scope = None;
+ while !expansion.is_descendant_of(self.outer()) {
+ scope = Some(self.remove_mark());
+ }
+ scope
+ }
+
+ /// Adjust this context for resolution in a scope created by the given expansion
+ /// via a glob import with the given `SyntaxContext`.
+ /// For example,
+ /// ```rust
+ /// m!(f);
+ /// macro m($i:ident) {
+ /// mod foo {
+ /// pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
+ /// pub fn $i() {} // `$i`'s `SyntaxContext` is empty.
+ /// }
+ /// n(f);
+ /// macro n($j:ident) {
+ /// use foo::*;
+ /// f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n`
+ /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::f`.
+ /// $i(); // `$i`'s `SyntaxContext` has a mark from `n`
+ /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::$i`.
+ /// $j(); // `$j`'s `SyntaxContext` has a mark from `m`
+ /// //^ This cannot be glob-adjusted, so this is a resolution error.
+ /// }
+ /// }
+ /// ```
+ /// This returns `None` if the context cannot be glob-adjusted.
+ /// Otherwise, it returns the scope to use when privacy checking (see `adjust` for details).
+ pub fn glob_adjust(&mut self, expansion: Mark, mut glob_ctxt: SyntaxContext)
+ -> Option<Option<Mark>> {
+ let mut scope = None;
+ while !expansion.is_descendant_of(glob_ctxt.outer()) {
+ scope = Some(glob_ctxt.remove_mark());
+ if self.remove_mark() != scope.unwrap() {
+ return None;
+ }
+ }
+ if self.adjust(expansion).is_some() {
+ return None;
+ }
+ Some(scope)
+ }
+
+ /// Undo `glob_adjust` if possible:
+ /// ```rust
+ /// if let Some(privacy_checking_scope) = self.reverse_glob_adjust(expansion, glob_ctxt) {
+ /// assert!(self.glob_adjust(expansion, glob_ctxt) == Some(privacy_checking_scope));
+ /// }
+ /// ```
+ pub fn reverse_glob_adjust(&mut self, expansion: Mark, mut glob_ctxt: SyntaxContext)
+ -> Option<Option<Mark>> {
+ if self.adjust(expansion).is_some() {
+ return None;
+ }
+
+ let mut marks = Vec::new();
+ while !expansion.is_descendant_of(glob_ctxt.outer()) {
+ marks.push(glob_ctxt.remove_mark());
+ }
+
+ let scope = marks.last().cloned();
+ while let Some(mark) = marks.pop() {
+ *self = self.apply_mark(mark);
+ }
+ Some(scope)
+ }
+
+ pub fn modern(self) -> SyntaxContext {
+ HygieneData::with(|data| data.syntax_contexts[self.0 as usize].modern)
+ }
+
pub fn outer(self) -> Mark {
HygieneData::with(|data| data.syntax_contexts[self.0 as usize].outer_mark)
}
projects / rust.git / blobdiff