rustdoc/formats/
mod.rs

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1pub(crate) mod cache;
2pub(crate) mod item_type;
3pub(crate) mod renderer;
4
5pub(crate) use renderer::{FormatRenderer, run_format};
6use rustc_hir::def_id::DefId;
7
8use crate::clean::{self, ItemId};
9use crate::html::render::Context;
10
11/// Metadata about implementations for a type or trait.
12#[derive(Clone, Debug)]
13pub(crate) struct Impl {
14    pub(crate) impl_item: clean::Item,
15}
16
17impl Impl {
18    pub(crate) fn inner_impl(&self) -> &clean::Impl {
19        match self.impl_item.kind {
20            clean::ImplItem(ref impl_) => impl_,
21            _ => panic!("non-impl item found in impl"),
22        }
23    }
24
25    pub(crate) fn trait_did(&self) -> Option<DefId> {
26        self.inner_impl().trait_.as_ref().map(|t| t.def_id())
27    }
28
29    /// This function is used to extract a `DefId` to be used as a key for the `Cache::impls` field.
30    ///
31    /// It allows to prevent having duplicated implementations showing up (the biggest issue was
32    /// with blanket impls).
33    ///
34    /// It panics if `self` is a `ItemId::Primitive`.
35    pub(crate) fn def_id(&self) -> DefId {
36        match self.impl_item.item_id {
37            ItemId::Blanket { impl_id, .. } => impl_id,
38            ItemId::Auto { trait_, .. } => trait_,
39            ItemId::DefId(def_id) => def_id,
40        }
41    }
42
43    // Returns true if this is an implementation on a "local" type, meaning:
44    // the type is in the current crate, or the type and the trait are both
45    // re-exported by the current crate.
46    pub(crate) fn is_on_local_type(&self, cx: &Context<'_>) -> bool {
47        let cache = cx.cache();
48        let for_type = &self.inner_impl().for_;
49        if let Some(for_type_did) = for_type.def_id(cache) {
50            // The "for" type is local if it's in the paths for the current crate.
51            if cache.paths.contains_key(&for_type_did) {
52                return true;
53            }
54            if let Some(trait_did) = self.trait_did() {
55                // The "for" type and the trait are from the same crate. That could
56                // be different from the current crate, for instance when both were
57                // re-exported from some other crate. But they are local with respect to
58                // each other.
59                if for_type_did.krate == trait_did.krate {
60                    return true;
61                }
62                // Hack: many traits and types in std are re-exported from
63                // core or alloc. In general, rustdoc is capable of recognizing
64                // these implementations as being on local types. However, in at
65                // least one case (https://github.com/rust-lang/rust/issues/97610),
66                // rustdoc gets confused and labels an implementation as being on
67                // a foreign type. To make sure that confusion doesn't pass on to
68                // the reader, consider all implementations in std, core, and alloc
69                // to be on local types.
70                let crate_name = cx.tcx().crate_name(trait_did.krate);
71                if matches!(crate_name.as_str(), "std" | "core" | "alloc") {
72                    return true;
73                }
74            }
75            return false;
76        };
77        true
78    }
79}
rustdoc/formats/mod.rs

rustdoc/formats/
mod.rs
