mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid quadratic complexity.

Browse Source
This commit is contained in:
Jeffrey Seyfried 2016-10-08 00:30:24 +00:00
parent fbc96e18ad
commit 53fd3b0acc
1 changed files with 18 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/librustc_resolve/macros.rs
View File

@ -60,6 +60,19 @@ pub enum LegacyScope<'a> {
Binding(&'a LegacyBinding<'a>),
}
impl<'a> LegacyScope<'a> {
fn simplify_expansion(mut invoc: &'a InvocationData<'a>) -> Self {
while let LegacyScope::Invocation(_) = invoc.expansion.get() {
match invoc.legacy_scope.get() {
LegacyScope::Expansion(new_invoc) => invoc = new_invoc,
LegacyScope::Binding(_) => break,
scope @ _ => return scope,
}
}
LegacyScope::Expansion(invoc)
}
}
pub struct LegacyBinding<'a> {
parent: LegacyScope<'a>,
kind: LegacyBindingKind,
@ -175,8 +188,11 @@ impl<'a> base::Resolver for Resolver<'a> {
InvocationKind::Attr { ref attr, .. } => (intern(&*attr.name()), attr.span),
};
let scope = self.invocations[&scope].legacy_scope.get();
self.resolve_macro_name(scope, name, true).or_else(|| {
let invocation = self.invocations[&scope];
if let LegacyScope::Expansion(parent) = invocation.legacy_scope.get() {
invocation.legacy_scope.set(LegacyScope::simplify_expansion(parent));
}
self.resolve_macro_name(invocation.legacy_scope.get(), name, true).or_else(|| {
let mut err =
self.session.struct_span_err(span, &format!("macro undefined: '{}!'", name));
self.suggest_macro_name(&name.as_str(), &mut err);