From 64b5464f303ec2e0561e8d879d6d43691743f392 Mon Sep 17 00:00:00 2001
From: Tom Jakubowski <tom@crystae.net>
Date: Wed, 17 Dec 2014 02:39:10 -0800
Subject: [PATCH] rustdoc: Use Fn trait sugar for external paths
Fix #19909
---
src/librustdoc/clean/mod.rs | 58 +++++++++++++++++++++++++++++--------
1 file changed, 46 insertions(+), 12 deletions(-)
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 8dae353c64f..e28e125caa4 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -515,21 +515,55 @@ impl Clean<Vec<TyParamBound>> for ty::ExistentialBounds {
}
}
-fn external_path(cx: &DocContext, name: &str, substs: &subst::Substs) -> Path {
+fn external_path_params(cx: &DocContext, trait_did: Option<ast::DefId>,
+ substs: &subst::Substs) -> PathParameters {
+ use rustc::middle::ty::sty;
let lifetimes = substs.regions().get_slice(subst::TypeSpace)
.iter()
.filter_map(|v| v.clean(cx))
.collect();
let types = substs.types.get_slice(subst::TypeSpace).to_vec();
- let types = types.clean(cx);
+
+ match (trait_did, cx.tcx_opt()) {
+ // Attempt to sugar an external path like Fn<(A, B,), C> to Fn(A, B) -> C
+ (Some(did), Some(ref tcx)) if tcx.lang_items.fn_trait_kind(did).is_some() => {
+ assert_eq!(types.len(), 2);
+ let inputs = match types[0].sty {
+ sty::ty_tup(ref tys) => tys.iter().map(|t| t.clean(cx)).collect(),
+ _ => {
+ return PathParameters::AngleBracketed {
+ lifetimes: lifetimes,
+ types: types.clean(cx)
+ }
+ }
+ };
+ let output = match types[1].sty {
+ sty::ty_tup(ref v) if v.is_empty() => None, // -> ()
+ _ => Some(types[1].clean(cx))
+ };
+ PathParameters::Parenthesized {
+ inputs: inputs,
+ output: output
+ }
+ },
+ (_, _) => {
+ PathParameters::AngleBracketed {
+ lifetimes: lifetimes,
+ types: types.clean(cx),
+ }
+ }
+ }
+}
+
+// trait_did should be set to a trait's DefId if called on a TraitRef, in order to sugar
+// from Fn<(A, B,), C> to Fn(A, B) -> C
+fn external_path(cx: &DocContext, name: &str, trait_did: Option<ast::DefId>,
+ substs: &subst::Substs) -> Path {
Path {
global: false,
segments: vec![PathSegment {
name: name.to_string(),
- params: PathParameters::AngleBracketed {
- lifetimes: lifetimes,
- types: types,
- }
+ params: external_path_params(cx, trait_did, substs)
}],
}
}
@@ -544,16 +578,16 @@ impl Clean<TyParamBound> for ty::BuiltinBound {
let (did, path) = match *self {
ty::BoundSend =>
(tcx.lang_items.send_trait().unwrap(),
- external_path(cx, "Send", &empty)),
+ external_path(cx, "Send", None, &empty)),
ty::BoundSized =>
(tcx.lang_items.sized_trait().unwrap(),
- external_path(cx, "Sized", &empty)),
+ external_path(cx, "Sized", None, &empty)),
ty::BoundCopy =>
(tcx.lang_items.copy_trait().unwrap(),
- external_path(cx, "Copy", &empty)),
+ external_path(cx, "Copy", None, &empty)),
ty::BoundSync =>
(tcx.lang_items.sync_trait().unwrap(),
- external_path(cx, "Sync", &empty)),
+ external_path(cx, "Sync", None, &empty)),
};
let fqn = csearch::get_item_path(tcx, did);
let fqn = fqn.into_iter().map(|i| i.to_string()).collect();
@@ -586,7 +620,7 @@ impl<'tcx> Clean<TyParamBound> for ty::TraitRef<'tcx> {
let fqn = fqn.into_iter().map(|i| i.to_string())
.collect::<Vec<String>>();
let path = external_path(cx, fqn.last().unwrap().as_slice(),
- &self.substs);
+ Some(self.def_id), &self.substs);
cx.external_paths.borrow_mut().as_mut().unwrap().insert(self.def_id,
(fqn, TypeTrait));
@@ -1437,7 +1471,7 @@ impl<'tcx> Clean<Type> for ty::Ty<'tcx> {
_ => TypeEnum,
};
let path = external_path(cx, fqn.last().unwrap().to_string().as_slice(),
- substs);
+ None, substs);
cx.external_paths.borrow_mut().as_mut().unwrap().insert(did, (fqn, kind));
ResolvedPath {
path: path,