Rollup merge of #81287 - CraftSpider:json-crate, r=jyn514,GuillaumeGomez

Split rustdoc JSON types into separately versioned crate

For now just an in-tree change.

In the future, this may be exposed as a standalone crate with standard semver.

8 files changed, 88 insertions, 59 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 992ebdb801a..a4ba7704426 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4392,6 +4392,7 @@ dependencies = [
  "pulldown-cmark 0.8.0",
  "regex",
  "rustc-rayon",
+ "rustdoc-json-types",
  "serde",
  "serde_json",
  "smallvec 1.4.2",
@@ -4399,6 +4400,13 @@ dependencies = [
 ]
 
 [[package]]
+name = "rustdoc-json-types"
+version = "0.1.0"
+dependencies = [
+ "serde",
+]
+
+[[package]]
 name = "rustdoc-themes"
 version = "0.1.0"
 
diff --git a/Cargo.toml b/Cargo.toml
index 5bd1147cad5..f3b2e0f740d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,7 @@ members = [
   "compiler/rustc",
   "library/std",
   "library/test",
+  "src/rustdoc-json-types",
   "src/tools/cargotest",
   "src/tools/clippy",
   "src/tools/compiletest",
diff --git a/src/librustdoc/Cargo.toml b/src/librustdoc/Cargo.toml
index b0f5bac6abd..db64b31f31c 100644
--- a/src/librustdoc/Cargo.toml
+++ b/src/librustdoc/Cargo.toml
@@ -17,6 +17,7 @@ smallvec = "1.0"
 tempfile = "3"
 itertools = "0.9"
 regex = "1"
+rustdoc-json-types = { path = "../rustdoc-json-types" }
 
 [dev-dependencies]
 expect-test = "1.0"
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index bfd2141d9a1..b2e5c8834b8 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -9,9 +9,10 @@ use rustc_hir::def::CtorKind;
 use rustc_span::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_span::Pos;
 
+use rustdoc_json_types::*;
+
 use crate::clean;
 use crate::formats::item_type::ItemType;
-use crate::json::types::*;
 use crate::json::JsonRenderer;
 
 impl JsonRenderer<'_> {
@@ -22,7 +23,7 @@ impl JsonRenderer<'_> {
         match *kind {
             clean::StrippedItem(_) => None,
             kind => Some(Item {
-                id: def_id.into(),
+                id: from_def_id(def_id),
                 crate_id: def_id.krate.as_u32(),
                 name: name.map(|sym| sym.to_string()),
                 source: self.convert_span(source),
@@ -32,7 +33,7 @@ impl JsonRenderer<'_> {
                     .links
                     .into_iter()
                     .filter_map(|clean::ItemLink { link, did, .. }| {
-                        did.map(|did| (link, did.into()))
+                        did.map(|did| (link, from_def_id(did)))
                     })
                     .collect(),
                 attrs: attrs
@@ -40,7 +41,7 @@ impl JsonRenderer<'_> {
                     .iter()
                     .map(rustc_ast_pretty::pprust::attribute_to_string)
                     .collect(),
-                deprecation: deprecation.map(Into::into),
+                deprecation: deprecation.map(from_deprecation),
                 kind: item_type.into(),
                 inner: kind.into(),
             }),
@@ -74,19 +75,17 @@ impl JsonRenderer<'_> {
             Inherited => Visibility::Default,
             Restricted(did) if did.index == CRATE_DEF_INDEX => Visibility::Crate,
             Restricted(did) => Visibility::Restricted {
-                parent: did.into(),
+                parent: from_def_id(did),
                 path: self.tcx.def_path(did).to_string_no_crate_verbose(),
             },
         }
     }
 }
 
-impl From<rustc_attr::Deprecation> for Deprecation {
-    fn from(deprecation: rustc_attr::Deprecation) -> Self {
-        #[rustfmt::skip]
-        let rustc_attr::Deprecation { since, note, is_since_rustc_version: _, suggestion: _ } = deprecation;
-        Deprecation { since: since.map(|s| s.to_string()), note: note.map(|s| s.to_string()) }
-    }
+crate fn from_deprecation(deprecation: rustc_attr::Deprecation) -> Deprecation {
+    #[rustfmt::skip]
+    let rustc_attr::Deprecation { since, note, is_since_rustc_version: _, suggestion: _ } = deprecation;
+    Deprecation { since: since.map(|s| s.to_string()), note: note.map(|s| s.to_string()) }
 }
 
 impl From<clean::GenericArgs> for GenericArgs {
@@ -141,10 +140,8 @@ impl From<clean::TypeBindingKind> for TypeBindingKind {
     }
 }
 
-impl From<DefId> for Id {
-    fn from(did: DefId) -> Self {
-        Id(format!("{}:{}", did.krate.as_u32(), u32::from(did.index)))
-    }
+crate fn from_def_id(did: DefId) -> Id {
+    Id(format!("{}:{}", did.krate.as_u32(), u32::from(did.index)))
 }
 
 impl From<clean::ItemKind> for ItemEnum {
@@ -199,7 +196,7 @@ impl From<clean::Struct> for Struct {
     fn from(struct_: clean::Struct) -> Self {
         let clean::Struct { struct_type, generics, fields, fields_stripped } = struct_;
         Struct {
-            struct_type: struct_type.into(),
+            struct_type: from_ctor_kind(struct_type),
             generics: generics.into(),
             fields_stripped,
             fields: ids(fields),
@@ -221,13 +218,11 @@ impl From<clean::Union> for Struct {
     }
 }
 
-impl From<CtorKind> for StructType {
-    fn from(struct_type: CtorKind) -> Self {
-        match struct_type {
-            CtorKind::Fictive => StructType::Plain,
-            CtorKind::Fn => StructType::Tuple,
-            CtorKind::Const => StructType::Unit,
-        }
+crate fn from_ctor_kind(struct_type: CtorKind) -> StructType {
+    match struct_type {
+        CtorKind::Fictive => StructType::Plain,
+        CtorKind::Fn => StructType::Tuple,
+        CtorKind::Const => StructType::Unit,
     }
 }
 
@@ -310,7 +305,7 @@ impl From<clean::GenericBound> for GenericBound {
                 GenericBound::TraitBound {
                     trait_: trait_.into(),
                     generic_params: generic_params.into_iter().map(Into::into).collect(),
-                    modifier: modifier.into(),
+                    modifier: from_trait_bound_modifier(modifier),
                 }
             }
             Outlives(lifetime) => GenericBound::Outlives(lifetime.0.to_string()),
@@ -318,14 +313,12 @@ impl From<clean::GenericBound> for GenericBound {
     }
 }
 
-impl From<rustc_hir::TraitBoundModifier> for TraitBoundModifier {
-    fn from(modifier: rustc_hir::TraitBoundModifier) -> Self {
-        use rustc_hir::TraitBoundModifier::*;
-        match modifier {
-            None => TraitBoundModifier::None,
-            Maybe => TraitBoundModifier::Maybe,
-            MaybeConst => TraitBoundModifier::MaybeConst,
-        }
+crate fn from_trait_bound_modifier(modifier: rustc_hir::TraitBoundModifier) -> TraitBoundModifier {
+    use rustc_hir::TraitBoundModifier::*;
+    match modifier {
+        None => TraitBoundModifier::None,
+        Maybe => TraitBoundModifier::Maybe,
+        MaybeConst => TraitBoundModifier::MaybeConst,
     }
 }
 
@@ -335,7 +328,7 @@ impl From<clean::Type> for Type {
         match ty {
             ResolvedPath { path, param_names, did, is_generic: _ } => Type::ResolvedPath {
                 name: path.whole_name(),
-                id: did.into(),
+                id: from_def_id(did),
                 args: path.segments.last().map(|args| Box::new(args.clone().args.into())),
                 param_names: param_names
                     .map(|v| v.into_iter().map(Into::into).collect())
@@ -470,7 +463,7 @@ impl From<clean::VariantStruct> for Struct {
     fn from(struct_: clean::VariantStruct) -> Self {
         let clean::VariantStruct { struct_type, fields, fields_stripped } = struct_;
         Struct {
-            struct_type: struct_type.into(),
+            struct_type: from_ctor_kind(struct_type),
             generics: Default::default(),
             fields_stripped,
             fields: ids(fields),
@@ -497,13 +490,13 @@ impl From<clean::Import> for Import {
             Simple(s) => Import {
                 span: import.source.path.whole_name(),
                 name: s.to_string(),
-                id: import.source.did.map(Into::into),
+                id: import.source.did.map(from_def_id),
                 glob: false,
             },
             Glob => Import {
                 span: import.source.path.whole_name(),
                 name: import.source.path.last_name().to_string(),
-                id: import.source.did.map(Into::into),
+                id: import.source.did.map(from_def_id),
                 glob: true,
             },
         }
@@ -513,20 +506,18 @@ impl From<clean::Import> for Import {
 impl From<clean::ProcMacro> for ProcMacro {
     fn from(mac: clean::ProcMacro) -> Self {
         ProcMacro {
-            kind: mac.kind.into(),
+            kind: from_macro_kind(mac.kind),
             helpers: mac.helpers.iter().map(|x| x.to_string()).collect(),
         }
     }
 }
 
-impl From<rustc_span::hygiene::MacroKind> for MacroKind {
-    fn from(kind: rustc_span::hygiene::MacroKind) -> Self {
-        use rustc_span::hygiene::MacroKind::*;
-        match kind {
-            Bang => MacroKind::Bang,
-            Attr => MacroKind::Attr,
-            Derive => MacroKind::Derive,
-        }
+crate fn from_macro_kind(kind: rustc_span::hygiene::MacroKind) -> MacroKind {
+    use rustc_span::hygiene::MacroKind::*;
+    match kind {
+        Bang => MacroKind::Bang,
+        Attr => MacroKind::Attr,
+        Derive => MacroKind::Derive,
     }
 }
 
@@ -599,5 +590,5 @@ impl From<ItemType> for ItemKind {
 }
 
 fn ids(items: impl IntoIterator<Item = clean::Item>) -> Vec<Id> {
-    items.into_iter().filter(|x| !x.is_stripped()).map(|i| i.def_id.into()).collect()
+    items.into_iter().filter(|x| !x.is_stripped()).map(|i| from_def_id(i.def_id)).collect()
 }
diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index a8a4b74b818..a7c875fb748 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -5,7 +5,6 @@
 //! docs for usage and details.
 
 mod conversions;
-pub mod types;
 
 use std::cell::RefCell;
 use std::fs::File;
@@ -17,12 +16,15 @@ use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::edition::Edition;
 
+use rustdoc_json_types as types;
+
 use crate::clean;
 use crate::config::{RenderInfo, RenderOptions};
 use crate::error::Error;
 use crate::formats::cache::Cache;
 use crate::formats::FormatRenderer;
 use crate::html::render::cache::ExternalLocation;
+use crate::json::conversions::from_def_id;
 
 #[derive(Clone)]
 crate struct JsonRenderer<'tcx> {
@@ -50,7 +52,7 @@ impl JsonRenderer<'_> {
                     .map(|i| {
                         let item = &i.impl_item;
                         self.item(item.clone()).unwrap();
-                        item.def_id.into()
+                        from_def_id(item.def_id)
                     })
                     .collect()
             })
@@ -68,7 +70,7 @@ impl JsonRenderer<'_> {
                         let item = &i.impl_item;
                         if item.def_id.is_local() {
                             self.item(item.clone()).unwrap();
-                            Some(item.def_id.into())
+                            Some(from_def_id(item.def_id))
                         } else {
                             None
                         }
@@ -87,9 +89,9 @@ impl JsonRenderer<'_> {
                 if !id.is_local() {
                     trait_item.items.clone().into_iter().for_each(|i| self.item(i).unwrap());
                     Some((
-                        id.into(),
+                        from_def_id(id),
                         types::Item {
-                            id: id.into(),
+                            id: from_def_id(id),
                             crate_id: id.krate.as_u32(),
                             name: self
                                 .cache
@@ -163,7 +165,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
             } else if let types::ItemEnum::EnumItem(ref mut e) = new_item.inner {
                 e.impls = self.get_impls(id)
             }
-            let removed = self.index.borrow_mut().insert(id.into(), new_item.clone());
+            let removed = self.index.borrow_mut().insert(from_def_id(id), new_item.clone());
             // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
             // to make sure the items are unique.
             if let Some(old_item) = removed {
@@ -203,11 +205,14 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         debug!("Done with crate");
         let mut index = (*self.index).clone().into_inner();
         index.extend(self.get_trait_items());
+        // This needs to be the default HashMap for compatibility with the public interface for
+        // rustdoc-json
+        #[allow(rustc::default_hash_types)]
         let output = types::Crate {
             root: types::Id(String::from("0:0")),
             crate_version: krate.version.clone(),
             includes_private: self.cache.document_private,
-            index,
+            index: index.into_iter().collect(),
             paths: self
                 .cache
                 .paths
@@ -216,7 +221,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
                 .chain(self.cache.external_paths.clone().into_iter())
                 .map(|(k, (path, kind))| {
                     (
-                        k.into(),
+                        from_def_id(k),
                         types::ItemSummary { crate_id: k.krate.as_u32(), path, kind: kind.into() },
                     )
                 })
diff --git a/src/rustdoc-json-types/Cargo.toml b/src/rustdoc-json-types/Cargo.toml
new file mode 100644
index 00000000000..7bba16a68b9
--- /dev/null
+++ b/src/rustdoc-json-types/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "rustdoc-json-types"
+version = "0.1.0"
+authors = ["The Rust Project Developers"]
+edition = "2018"
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
diff --git a/src/rustdoc-json-types/README.md b/src/rustdoc-json-types/README.md
new file mode 100644
index 00000000000..1e67d37655c
--- /dev/null
+++ b/src/rustdoc-json-types/README.md
@@ -0,0 +1,12 @@
+# Rustdoc JSON Types
+
+This crate exposes the Rustdoc JSON API as a set of types with serde implementations.
+These types are part of the public interface of the rustdoc JSON output, and making them
+their own crate allows them to be versioned and distributed without having to depend on
+any rustc/rustdoc internals. This way, consumers can rely on this crate for both documentation
+of the output, and as a way to read the output easily, and its versioning is intended to
+follow semver guarantees about the version of the format. JSON format X will always be
+compatible with rustdoc-json-types version N.
+
+Currently, this crate is only used by rustdoc itself. Upon the stabilization of
+rustdoc-json, it may be distributed separately for consumers of the API.
diff --git a/src/librustdoc/json/types.rs b/src/rustdoc-json-types/lib.rs
index 66cf12954dd..3fb2a32d5a0 100644
--- a/src/librustdoc/json/types.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -3,9 +3,9 @@
 //! These types are the public API exposed through the `--output-format json` flag. The [`Crate`]
 //! struct is the root of the JSON blob and all other items are contained within.
 
+use std::collections::HashMap;
 use std::path::PathBuf;
 
-use rustc_data_structures::fx::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 /// A `Crate` is the root of the emitted JSON blob. It contains all type/documentation information
@@ -21,11 +21,11 @@ pub struct Crate {
     pub includes_private: bool,
     /// A collection of all items in the local crate as well as some external traits and their
     /// items that are referenced locally.
-    pub index: FxHashMap<Id, Item>,
+    pub index: HashMap<Id, Item>,
     /// Maps IDs to fully qualified paths and other info helpful for generating links.
-    pub paths: FxHashMap<Id, ItemSummary>,
+    pub paths: HashMap<Id, ItemSummary>,
     /// Maps `crate_id` of items to a crate name and html_root_url if it exists.
-    pub external_crates: FxHashMap<u32, ExternalCrate>,
+    pub external_crates: HashMap<u32, ExternalCrate>,
     /// A single version number to be used in the future when making backwards incompatible changes
     /// to the JSON output.
     pub format_version: u32,
@@ -72,7 +72,7 @@ pub struct Item {
     /// Some("") if there is some documentation but it is empty (EG `#[doc = ""]`).
     pub docs: Option<String>,
     /// This mapping resolves [intra-doc links](https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md) from the docstring to their IDs
-    pub links: FxHashMap<String, Id>,
+    pub links: HashMap<String, Id>,
     /// Stringified versions of the attributes on this item (e.g. `"#[inline]"`)
     pub attrs: Vec<String>,
     pub deprecation: Option<Deprecation>,