From 34fcc76312e340c69a6f8821442e4a55d0b4ca5f Mon Sep 17 00:00:00 2001
From: Andreas Molzer <andreas.molzer@gmx.de>
Date: Sat, 19 Sep 2020 04:28:32 +0200
Subject: [PATCH] Add type definitions for rustdoc JSON backend

---
 src/librustdoc/json/mod.rs   |   2 +
 src/librustdoc/json/types.rs | 274 +++++++++++++++++++++++++++++++++++
 2 files changed, 276 insertions(+)
 create mode 100644 src/librustdoc/json/types.rs

diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index 14f87ec2aa9bb..e77a02bcf996f 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -6,6 +6,8 @@ use crate::formats::FormatRenderer;
 
 use rustc_span::edition::Edition;
 
+mod types;
+
 #[derive(Clone)]
 pub struct JsonRenderer {}
 
diff --git a/src/librustdoc/json/types.rs b/src/librustdoc/json/types.rs
new file mode 100644
index 0000000000000..a0cd4242bbb46
--- /dev/null
+++ b/src/librustdoc/json/types.rs
@@ -0,0 +1,274 @@
+//! Defines the types and by extension the structure used for serialization.
+use serde::Serialize;
+use std::collections::HashMap;
+
+#[derive(Serialize)]
+struct Crate {
+    name: String,
+    version: String,
+    includes_private: bool,
+    root: Id,
+    index: HashMap<Id, Item>,
+    paths: HashMap<Id, ItemSummary>,
+    extern_crates: HashMap<Id, ExternalCrate>,
+    format_version: u32,
+}
+
+#[derive(Serialize)]
+struct Item {
+    crate_id: u32,
+    name: String,
+    span: Option<Span>,
+    visibility: String,
+    docs: String,
+    links: HashMap<String, Id>,
+    attrs: Vec<String>,
+    deprecation: Option<Deprecation>,
+    #[serde(flatten)]
+    inner: ItemInner,
+}
+
+#[derive(Serialize)]
+#[serde(tag = "kind", content = "inner")]
+enum ItemInner {
+    #[serde(rename = "module")]
+    Module { items: Vec<Id> },
+    #[serde(rename = "function")]
+    Function { decl: FnDecl, generics: Generics, header: String, abi: String },
+    #[serde(rename = "struct")]
+    Struct {
+        struct_type: String,
+        generics: Generics,
+        fields_stripped: bool,
+        fields: Vec<Id>,
+        impls: Vec<Id>,
+    },
+    #[serde(rename = "union")]
+    Union {
+        struct_type: String,
+        generics: Generics,
+        fields_stripped: bool,
+        fields: Vec<Id>,
+        impls: Vec<Id>,
+    },
+    #[serde(rename = "struct_field")]
+    StructField { r#type: Type },
+    #[serde(rename = "enum")]
+    Enum { generics: Generics, fields: Vec<Id>, fields_stripped: bool, impls: Vec<Id> },
+    #[serde(rename = "variant")]
+    Variant {
+        #[serde(flatten)]
+        inner: VariantInner,
+    },
+    #[serde(rename = "trait")]
+    Trait {
+        is_auto: bool,
+        is_unsafe: bool,
+        items: Vec<Id>,
+        generics: Generics,
+        bounds: Vec<GenericBound>,
+    },
+    #[serde(rename = "trait_alias")]
+    TraitAlias { generics: Generics, bounds: Vec<GenericBound> },
+    #[serde(rename = "method")]
+    Method { decl: FnDecl, generics: Generics, header: String, has_body: bool },
+    #[serde(rename = "assoc_const")]
+    AssocConst { r#type: Type, default: Option<String> },
+    #[serde(rename = "assoc_type")]
+    AssocType { bounds: Vec<GenericBound>, default: Option<Type> },
+    #[serde(rename = "impl")]
+    Impl {
+        is_unsafe: bool,
+        generics: Generics,
+        provided_trait_methods: Vec<String>,
+        r#trait: Option<Type>,
+        r#for: Type,
+        items: Vec<Id>,
+        negative: bool,
+        synthetic: bool,
+        blanket_impl: Option<String>,
+    },
+    #[serde(rename = "constant")]
+    Constant { r#type: Type, expr: String, value: Option<String>, is_literal: bool },
+    #[serde(rename = "static")]
+    Static { r#type: Type, expr: String, mutable: bool },
+    #[serde(rename = "typedef")]
+    Typedef { r#type: Type, generics: Generics },
+    #[serde(rename = "opaque_ty")]
+    OpaqueTy { bounds: Vec<GenericBound>, generics: Generics },
+    #[serde(rename = "foreign_type")]
+    ForeignType(),
+    #[serde(rename = "extern_crate")]
+    ExternCrate { name: String, rename: Option<String> },
+    #[serde(rename = "import")]
+    Import { source: String, name: String, id: Id, glob: bool },
+    #[serde(rename = "macro")]
+    Macro(String),
+}
+
+#[derive(Serialize)]
+#[serde(tag = "variant_kind", content = "variant_inner")]
+enum VariantInner {
+    #[serde(rename = "plain")]
+    Plain,
+    #[serde(rename = "tuple")]
+    Tuple(Vec<Type>),
+    #[serde(rename = "struct")]
+    Struct(Vec<Id>),
+}
+
+#[derive(Serialize)]
+#[serde(tag = "kind", content = "inner")]
+enum Type {
+    #[serde(rename = "resolved_path")]
+    ResolvedPath {
+        name: String,
+        args: Option<Box<GenericArgs>>,
+        id: Id,
+        param_names: Box<GenericBound>,
+    },
+    #[serde(rename = "generic")]
+    Generic(String),
+    #[serde(rename = "tuple")]
+    Tuple(Vec<Type>),
+    #[serde(rename = "slice")]
+    Slice(Box<Type>),
+    #[serde(rename = "array")]
+    Array { r#type: Box<Type>, len: String },
+    #[serde(rename = "impl_trait")]
+    ImplTrait(Vec<GenericBound>),
+    #[serde(rename = "never")]
+    Never,
+    #[serde(rename = "infer")]
+    Infer,
+    #[serde(rename = "function_pointer")]
+    FunctionPointer {
+        is_unsafe: bool,
+        decl: Box<FnDecl>,
+        params: Vec<GenericParamDef>,
+        abi: String,
+    },
+    #[serde(rename = "raw_pointer")]
+    RawPointer { mutable: bool, r#type: Box<Type> },
+    #[serde(rename = "borrowed_ref")]
+    BorrowedRef { lifetime: Option<String>, mutable: bool, r#type: Box<Type> },
+    #[serde(rename = "qualified_path")]
+    QualifiedPath { name: String, self_type: Box<Type>, r#trait: Box<Type> },
+}
+
+#[derive(Serialize)]
+enum GenericArgs {
+    #[serde(rename = "angle_bracketed")]
+    AngleBracketed { args: Vec<GenericArg>, bindings: TypeBinding },
+    #[serde(rename = "paranthesized")]
+    Paranthesized { inputs: Vec<Type>, output: Type },
+}
+
+#[derive(Serialize)]
+struct TypeBinding {
+    name: String,
+    binding: TypeBindingInner,
+}
+
+#[derive(Serialize)]
+enum TypeBindingInner {
+    #[serde(rename = "equality")]
+    Equality(Type),
+    #[serde(rename = "constraint")]
+    Constraint(Vec<GenericBound>),
+}
+
+#[derive(Serialize)]
+enum GenericArg {
+    #[serde(rename = "lifetime")]
+    Lifetime(String),
+    #[serde(rename = "type")]
+    Type(Type),
+    #[serde(rename = "const")]
+    Const { r#type: Type, expr: String, value: Option<String>, is_literal: bool },
+}
+
+#[derive(Serialize)]
+struct ItemSummary {
+    crate_id: u32,
+    path: Vec<String>,
+    kind: String,
+}
+
+#[derive(Serialize)]
+struct ExternalCrate {
+    name: String,
+    html_root_url: String,
+}
+
+#[derive(Serialize)]
+struct Visibility {
+    parent: Id,
+    path: String,
+}
+
+#[derive(Serialize)]
+struct Span {
+    filename: String,
+    begin: (u32, u32),
+    end: (u32, u32),
+}
+
+#[derive(Serialize)]
+struct Deprecation {
+    since: Option<String>,
+    note: Option<String>,
+}
+
+#[derive(Serialize)]
+struct FnDecl {
+    inputs: Vec<(String, Type)>,
+    output: Option<Type>,
+    c_variadic: bool,
+}
+
+#[derive(Serialize)]
+struct Generics {
+    params: Vec<GenericParamDef>,
+    where_predicates: Vec<WherePredicate>,
+}
+
+#[derive(Serialize)]
+struct GenericParamDef {
+    name: String,
+    kind: GenericParamDefInner,
+}
+
+#[derive(Serialize)]
+enum GenericParamDefInner {
+    #[serde(rename = "lifetime")]
+    Lifetime,
+    #[serde(rename = "const")]
+    Const(Type),
+    #[serde(rename = "type")]
+    Type {
+        bounds: Vec<GenericBound>,
+        default: Option<Type>,
+        // FIXME: this appears in RFC but not in the spec.
+        synthetic: Option<bool>,
+    },
+}
+
+#[derive(Serialize)]
+enum WherePredicate {
+    #[serde(rename = "bound_predicate")]
+    Bound { ty: Type, bounds: Vec<GenericBound> },
+    #[serde(rename = "region_predicate")]
+    Region { lifetime: String, bounds: Vec<GenericBound> },
+    #[serde(rename = "eq_predicate")]
+    Eq { lhs: Type, rhs: Type },
+}
+
+#[derive(Serialize)]
+enum GenericBound {
+    #[serde(rename = "trait_bound")]
+    TraitBound { r#trait: Type, modifier: String, generics_params: Vec<GenericParamDef> },
+}
+
+#[derive(Serialize, PartialEq, Eq, Hash)]
+struct Id(String);