Merging debian version 1.65.0+dfsg1-2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 776 insertions, 0 deletions

diff --git a/src/tools/jsondoclint/Cargo.toml b/src/tools/jsondoclint/Cargo.toml
new file mode 100644
index 000000000..84a6c7f96
--- /dev/null
+++ b/src/tools/jsondoclint/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "jsondoclint"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1.0.62"
+fs-err = "2.8.1"
+rustdoc-json-types = { version = "0.1.0", path = "../../rustdoc-json-types" }
+serde_json = "1.0.85"
diff --git a/src/tools/jsondoclint/src/item_kind.rs b/src/tools/jsondoclint/src/item_kind.rs
new file mode 100644
index 000000000..ad8e96a0b
--- /dev/null
+++ b/src/tools/jsondoclint/src/item_kind.rs
@@ -0,0 +1,184 @@
+use rustdoc_json_types::{Item, ItemEnum, ItemKind, ItemSummary};
+
+/// A univeral way to represent an [`ItemEnum`] or [`ItemKind`]
+#[derive(Debug)]
+pub(crate) enum Kind {
+    Module,
+    ExternCrate,
+    Import,
+    Struct,
+    StructField,
+    Union,
+    Enum,
+    Variant,
+    Function,
+    Typedef,
+    OpaqueTy,
+    Constant,
+    Trait,
+    TraitAlias,
+    Method,
+    Impl,
+    Static,
+    ForeignType,
+    Macro,
+    ProcAttribute,
+    ProcDerive,
+    AssocConst,
+    AssocType,
+    Primitive,
+    Keyword,
+    // Not in ItemKind
+    ProcMacro,
+}
+
+impl Kind {
+    pub fn can_appear_in_mod(self) -> bool {
+        use Kind::*;
+        match self {
+            Module => true,
+            ExternCrate => true,
+            Import => true,
+            Union => true,
+            Struct => true,
+            Enum => true,
+            Function => true,
+            Trait => true,
+            TraitAlias => true,
+            Impl => true,
+            Typedef => true,
+            Constant => true,
+            Static => true,
+            Macro => true,
+            ProcMacro => true,
+            Primitive => true,
+            ForeignType => true,
+
+            // FIXME(adotinthevoid): I'm not sure if these are corrent
+            Keyword => false,
+            OpaqueTy => false,
+            ProcAttribute => false,
+            ProcDerive => false,
+
+            // Only in traits
+            AssocConst => false,
+            AssocType => false,
+            Method => false,
+
+            StructField => false, // Only in structs or variants
+            Variant => false,     // Only in enums
+        }
+    }
+
+    pub fn can_appear_in_trait(self) -> bool {
+        match self {
+            Kind::AssocConst => true,
+            Kind::AssocType => true,
+            Kind::Method => true,
+
+            Kind::Module => false,
+            Kind::ExternCrate => false,
+            Kind::Import => false,
+            Kind::Struct => false,
+            Kind::StructField => false,
+            Kind::Union => false,
+            Kind::Enum => false,
+            Kind::Variant => false,
+            Kind::Function => false,
+            Kind::Typedef => false,
+            Kind::OpaqueTy => false,
+            Kind::Constant => false,
+            Kind::Trait => false,
+            Kind::TraitAlias => false,
+            Kind::Impl => false,
+            Kind::Static => false,
+            Kind::ForeignType => false,
+            Kind::Macro => false,
+            Kind::ProcAttribute => false,
+            Kind::ProcDerive => false,
+            Kind::Primitive => false,
+            Kind::Keyword => false,
+            Kind::ProcMacro => false,
+        }
+    }
+
+    pub fn is_struct_field(self) -> bool {
+        matches!(self, Kind::StructField)
+    }
+    pub fn is_module(self) -> bool {
+        matches!(self, Kind::Module)
+    }
+    pub fn is_impl(self) -> bool {
+        matches!(self, Kind::Impl)
+    }
+    pub fn is_variant(self) -> bool {
+        matches!(self, Kind::Variant)
+    }
+    pub fn is_trait(self) -> bool {
+        matches!(self, Kind::Trait)
+    }
+    pub fn is_struct_enum_union(self) -> bool {
+        matches!(self, Kind::Struct | Kind::Enum | Kind::Union)
+    }
+
+    pub fn from_item(i: &Item) -> Self {
+        use Kind::*;
+        match i.inner {
+            ItemEnum::Module(_) => Module,
+            ItemEnum::Import(_) => Import,
+            ItemEnum::Union(_) => Union,
+            ItemEnum::Struct(_) => Struct,
+            ItemEnum::StructField(_) => StructField,
+            ItemEnum::Enum(_) => Enum,
+            ItemEnum::Variant(_) => Variant,
+            ItemEnum::Function(_) => Function,
+            ItemEnum::Trait(_) => Trait,
+            ItemEnum::TraitAlias(_) => TraitAlias,
+            ItemEnum::Method(_) => Method,
+            ItemEnum::Impl(_) => Impl,
+            ItemEnum::Typedef(_) => Typedef,
+            ItemEnum::OpaqueTy(_) => OpaqueTy,
+            ItemEnum::Constant(_) => Constant,
+            ItemEnum::Static(_) => Static,
+            ItemEnum::Macro(_) => Macro,
+            ItemEnum::ProcMacro(_) => ProcMacro,
+            // https://github.com/rust-lang/rust/issues/100961
+            ItemEnum::PrimitiveType(_) => Primitive,
+            ItemEnum::ForeignType => ForeignType,
+            ItemEnum::ExternCrate { .. } => ExternCrate,
+            ItemEnum::AssocConst { .. } => AssocConst,
+            ItemEnum::AssocType { .. } => AssocType,
+        }
+    }
+
+    pub fn from_summary(s: &ItemSummary) -> Self {
+        use Kind::*;
+        match s.kind {
+            ItemKind::AssocConst => AssocConst,
+            ItemKind::AssocType => AssocType,
+            ItemKind::Constant => Constant,
+            ItemKind::Enum => Enum,
+            ItemKind::ExternCrate => ExternCrate,
+            ItemKind::ForeignType => ForeignType,
+            ItemKind::Function => Function,
+            ItemKind::Impl => Impl,
+            ItemKind::Import => Import,
+            ItemKind::Keyword => Keyword,
+            ItemKind::Macro => Macro,
+            ItemKind::Method => Method,
+            ItemKind::Module => Module,
+            ItemKind::OpaqueTy => OpaqueTy,
+            ItemKind::Primitive => Primitive,
+            ItemKind::ProcAttribute => ProcAttribute,
+            ItemKind::ProcDerive => ProcDerive,
+            ItemKind::Static => Static,
+            ItemKind::Struct => Struct,
+            ItemKind::StructField => StructField,
+            ItemKind::Trait => Trait,
+            ItemKind::TraitAlias => TraitAlias,
+            ItemKind::Typedef => Typedef,
+            ItemKind::Union => Union,
+            ItemKind::Variant => Variant,
+        }
+    }
+}
diff --git a/src/tools/jsondoclint/src/json_find.rs b/src/tools/jsondoclint/src/json_find.rs
new file mode 100644
index 000000000..95ea88666
--- /dev/null
+++ b/src/tools/jsondoclint/src/json_find.rs
@@ -0,0 +1,74 @@
+use std::fmt::Write;
+
+use serde_json::Value;
+
+#[derive(Debug, Clone)]
+pub enum SelectorPart {
+    Field(String),
+    Index(usize),
+}
+
+pub type Selector = Vec<SelectorPart>;
+
+pub fn to_jsonpath(sel: &Selector) -> String {
+    let mut s = String::from("$");
+    for part in sel {
+        match part {
+            SelectorPart::Field(name) => {
+                if is_jsonpath_safe(name) {
+                    write!(&mut s, ".{}", name).unwrap();
+                } else {
+                    // This is probably wrong in edge cases, but all Id's are
+                    // just ascii alphanumerics, `-` `_`, and `:`
+                    write!(&mut s, "[{name:?}]").unwrap();
+                }
+            }
+            SelectorPart::Index(idx) => write!(&mut s, "[{idx}]").unwrap(),
+        }
+    }
+    s
+}
+
+fn is_jsonpath_safe(s: &str) -> bool {
+    s.chars().all(|c| c.is_ascii_alphanumeric() || c == '_')
+}
+
+pub fn find_selector(haystack: &Value, needle: &Value) -> Vec<Selector> {
+    let mut result = Vec::new();
+    let mut sel = Selector::new();
+    find_selector_recursive(haystack, needle, &mut result, &mut sel);
+    result
+}
+
+fn find_selector_recursive(
+    haystack: &Value,
+    needle: &Value,
+    result: &mut Vec<Selector>,
+    pos: &mut Selector,
+) {
+    if needle == haystack {
+        result.push(pos.clone());
+        // Haystack cant both contain needle and be needle
+    } else {
+        match haystack {
+            Value::Null => {}
+            Value::Bool(_) => {}
+            Value::Number(_) => {}
+            Value::String(_) => {}
+            Value::Array(arr) => {
+                for (idx, subhaystack) in arr.iter().enumerate() {
+                    pos.push(SelectorPart::Index(idx));
+                    find_selector_recursive(subhaystack, needle, result, pos);
+                    pos.pop().unwrap();
+                }
+            }
+            Value::Object(obj) => {
+                for (key, subhaystack) in obj {
+                    pos.push(SelectorPart::Field(key.clone()));
+                    find_selector_recursive(subhaystack, needle, result, pos);
+                    pos.pop().unwrap();
+                }
+            }
+        }
+    }
+}
diff --git a/src/tools/jsondoclint/src/main.rs b/src/tools/jsondoclint/src/main.rs
new file mode 100644
index 000000000..70d7a82a5
--- /dev/null
+++ b/src/tools/jsondoclint/src/main.rs
@@ -0,0 +1,64 @@
+use std::env;
+
+use anyhow::{anyhow, bail, Result};
+use fs_err as fs;
+use rustdoc_json_types::{Crate, Id, FORMAT_VERSION};
+use serde_json::Value;
+
+pub(crate) mod item_kind;
+mod json_find;
+mod validator;
+
+#[derive(Debug)]
+struct Error {
+    kind: ErrorKind,
+    id: Id,
+}
+
+#[derive(Debug)]
+enum ErrorKind {
+    NotFound,
+    Custom(String),
+}
+
+fn main() -> Result<()> {
+    let path = env::args().nth(1).ok_or_else(|| anyhow!("no path given"))?;
+    let contents = fs::read_to_string(&path)?;
+    let krate: Crate = serde_json::from_str(&contents)?;
+    assert_eq!(krate.format_version, FORMAT_VERSION);
+
+    let mut validator = validator::Validator::new(&krate);
+    validator.check_crate();
+
+    if !validator.errs.is_empty() {
+        for err in validator.errs {
+            match err.kind {
+                ErrorKind::NotFound => {
+                    let krate_json: Value = serde_json::from_str(&contents)?;
+
+                    let sels =
+                        json_find::find_selector(&krate_json, &Value::String(err.id.0.clone()));
+                    match &sels[..] {
+                        [] => unreachable!(
+                            "id must be in crate, or it wouldn't be reported as not found"
+                        ),
+                        [sel] => eprintln!(
+                            "{} not in index or paths, but refered to at '{}'",
+                            err.id.0,
+                            json_find::to_jsonpath(&sel)
+                        ),
+                        [sel, ..] => eprintln!(
+                            "{} not in index or paths, but refered to at '{}' and more",
+                            err.id.0,
+                            json_find::to_jsonpath(&sel)
+                        ),
+                    }
+                }
+                ErrorKind::Custom(msg) => eprintln!("{}: {}", err.id.0, msg),
+            }
+        }
+        bail!("Errors validating json {path}");
+    }
+
+    Ok(())
+}
diff --git a/src/tools/jsondoclint/src/validator.rs b/src/tools/jsondoclint/src/validator.rs
new file mode 100644
index 000000000..a0e77127d
--- /dev/null
+++ b/src/tools/jsondoclint/src/validator.rs
@@ -0,0 +1,442 @@
+use std::collections::HashSet;
+use std::hash::Hash;
+
+use rustdoc_json_types::{
+    Constant, Crate, DynTrait, Enum, FnDecl, Function, FunctionPointer, GenericArg, GenericArgs,
+    GenericBound, GenericParamDef, Generics, Id, Impl, Import, ItemEnum, Method, Module, OpaqueTy,
+    Path, ProcMacro, Static, Struct, StructKind, Term, Trait, TraitAlias, Type, TypeBinding,
+    TypeBindingKind, Typedef, Union, Variant, WherePredicate,
+};
+
+use crate::{item_kind::Kind, Error, ErrorKind};
+
+/// The Validator walks over the JSON tree, and ensures it is well formed.
+/// It is made of several parts.
+///
+/// - `check_*`: These take a type from [`rustdoc_json_types`], and check that
+///              it is well formed. This involves calling `check_*` functions on
+///              fields of that item, and `add_*` functions on [`Id`]s.
+/// - `add_*`: These add an [`Id`] to the worklist, after validating it to check if
+///            the `Id` is a kind expected in this suituation.
+#[derive(Debug)]
+pub struct Validator<'a> {
+    pub(crate) errs: Vec<Error>,
+    krate: &'a Crate,
+    /// Worklist of Ids to check.
+    todo: HashSet<&'a Id>,
+    /// Ids that have already been visited, so don't need to be checked again.
+    seen_ids: HashSet<&'a Id>,
+    /// Ids that have already been reported missing.
+    missing_ids: HashSet<&'a Id>,
+}
+
+enum PathKind {
+    Trait,
+    StructEnumUnion,
+}
+
+impl<'a> Validator<'a> {
+    pub fn new(krate: &'a Crate) -> Self {
+        Self {
+            krate,
+            errs: Vec::new(),
+            seen_ids: HashSet::new(),
+            todo: HashSet::new(),
+            missing_ids: HashSet::new(),
+        }
+    }
+
+    pub fn check_crate(&mut self) {
+        let root = &self.krate.root;
+        self.add_mod_id(root);
+        while let Some(id) = set_remove(&mut self.todo) {
+            self.seen_ids.insert(id);
+            self.check_item(id);
+        }
+    }
+
+    fn check_item(&mut self, id: &'a Id) {
+        if let Some(item) = &self.krate.index.get(id) {
+            match &item.inner {
+                ItemEnum::Import(x) => self.check_import(x),
+                ItemEnum::Union(x) => self.check_union(x),
+                ItemEnum::Struct(x) => self.check_struct(x),
+                ItemEnum::StructField(x) => self.check_struct_field(x),
+                ItemEnum::Enum(x) => self.check_enum(x),
+                ItemEnum::Variant(x) => self.check_variant(x, id),
+                ItemEnum::Function(x) => self.check_function(x),
+                ItemEnum::Trait(x) => self.check_trait(x),
+                ItemEnum::TraitAlias(x) => self.check_trait_alias(x),
+                ItemEnum::Method(x) => self.check_method(x),
+                ItemEnum::Impl(x) => self.check_impl(x),
+                ItemEnum::Typedef(x) => self.check_typedef(x),
+                ItemEnum::OpaqueTy(x) => self.check_opaque_ty(x),
+                ItemEnum::Constant(x) => self.check_constant(x),
+                ItemEnum::Static(x) => self.check_static(x),
+                ItemEnum::ForeignType => {} // nop
+                ItemEnum::Macro(x) => self.check_macro(x),
+                ItemEnum::ProcMacro(x) => self.check_proc_macro(x),
+                ItemEnum::PrimitiveType(x) => self.check_primitive_type(x),
+                ItemEnum::Module(x) => self.check_module(x),
+                // FIXME: Why don't these have their own structs?
+                ItemEnum::ExternCrate { .. } => {}
+                ItemEnum::AssocConst { type_, default: _ } => self.check_type(type_),
+                ItemEnum::AssocType { generics, bounds, default } => {
+                    self.check_generics(generics);
+                    bounds.iter().for_each(|b| self.check_generic_bound(b));
+                    if let Some(ty) = default {
+                        self.check_type(ty);
+                    }
+                }
+            }
+        } else {
+            assert!(self.krate.paths.contains_key(id));
+        }
+    }
+
+    // Core checkers
+    fn check_module(&mut self, module: &'a Module) {
+        module.items.iter().for_each(|i| self.add_mod_item_id(i));
+    }
+
+    fn check_import(&mut self, x: &'a Import) {
+        if x.glob {
+            self.add_mod_id(x.id.as_ref().unwrap());
+        } else if let Some(id) = &x.id {
+            self.add_mod_item_id(id);
+        }
+    }
+
+    fn check_union(&mut self, x: &'a Union) {
+        self.check_generics(&x.generics);
+        x.fields.iter().for_each(|i| self.add_field_id(i));
+        x.impls.iter().for_each(|i| self.add_impl_id(i));
+    }
+
+    fn check_struct(&mut self, x: &'a Struct) {
+        self.check_generics(&x.generics);
+        match &x.kind {
+            StructKind::Unit => {}
+            StructKind::Tuple(fields) => fields.iter().flatten().for_each(|f| self.add_field_id(f)),
+            StructKind::Plain { fields, fields_stripped: _ } => {
+                fields.iter().for_each(|f| self.add_field_id(f))
+            }
+        }
+        x.impls.iter().for_each(|i| self.add_impl_id(i));
+    }
+
+    fn check_struct_field(&mut self, x: &'a Type) {
+        self.check_type(x);
+    }
+
+    fn check_enum(&mut self, x: &'a Enum) {
+        self.check_generics(&x.generics);
+        x.variants.iter().for_each(|i| self.add_variant_id(i));
+        x.impls.iter().for_each(|i| self.add_impl_id(i));
+    }
+
+    fn check_variant(&mut self, x: &'a Variant, id: &'a Id) {
+        match x {
+            Variant::Plain(discr) => {
+                if let Some(discr) = discr {
+                    if let (Err(_), Err(_)) =
+                        (discr.value.parse::<i128>(), discr.value.parse::<u128>())
+                    {
+                        self.fail(
+                            id,
+                            ErrorKind::Custom(format!(
+                                "Failed to parse discriminant value `{}`",
+                                discr.value
+                            )),
+                        );
+                    }
+                }
+            }
+            Variant::Tuple(tys) => tys.iter().flatten().for_each(|t| self.add_field_id(t)),
+            Variant::Struct { fields, fields_stripped: _ } => {
+                fields.iter().for_each(|f| self.add_field_id(f))
+            }
+        }
+    }
+
+    fn check_function(&mut self, x: &'a Function) {
+        self.check_generics(&x.generics);
+        self.check_fn_decl(&x.decl);
+    }
+
+    fn check_trait(&mut self, x: &'a Trait) {
+        self.check_generics(&x.generics);
+        x.items.iter().for_each(|i| self.add_trait_item_id(i));
+        x.bounds.iter().for_each(|i| self.check_generic_bound(i));
+        x.implementations.iter().for_each(|i| self.add_impl_id(i));
+    }
+
+    fn check_trait_alias(&mut self, x: &'a TraitAlias) {
+        self.check_generics(&x.generics);
+        x.params.iter().for_each(|i| self.check_generic_bound(i));
+    }
+
+    fn check_method(&mut self, x: &'a Method) {
+        self.check_fn_decl(&x.decl);
+        self.check_generics(&x.generics);
+    }
+
+    fn check_impl(&mut self, x: &'a Impl) {
+        self.check_generics(&x.generics);
+        if let Some(path) = &x.trait_ {
+            self.check_path(path, PathKind::Trait);
+        }
+        self.check_type(&x.for_);
+        x.items.iter().for_each(|i| self.add_trait_item_id(i));
+        if let Some(blanket_impl) = &x.blanket_impl {
+            self.check_type(blanket_impl)
+        }
+    }
+
+    fn check_typedef(&mut self, x: &'a Typedef) {
+        self.check_generics(&x.generics);
+        self.check_type(&x.type_);
+    }
+
+    fn check_opaque_ty(&mut self, x: &'a OpaqueTy) {
+        x.bounds.iter().for_each(|b| self.check_generic_bound(b));
+        self.check_generics(&x.generics);
+    }
+
+    fn check_constant(&mut self, x: &'a Constant) {
+        self.check_type(&x.type_);
+    }
+
+    fn check_static(&mut self, x: &'a Static) {
+        self.check_type(&x.type_);
+    }
+
+    fn check_macro(&mut self, _: &'a str) {
+        // nop
+    }
+
+    fn check_proc_macro(&mut self, _: &'a ProcMacro) {
+        // nop
+    }
+
+    fn check_primitive_type(&mut self, _: &'a str) {
+        // nop
+    }
+
+    fn check_generics(&mut self, x: &'a Generics) {
+        x.params.iter().for_each(|p| self.check_generic_param_def(p));
+        x.where_predicates.iter().for_each(|w| self.check_where_predicate(w));
+    }
+
+    fn check_type(&mut self, x: &'a Type) {
+        match x {
+            Type::ResolvedPath(path) => self.check_path(path, PathKind::StructEnumUnion),
+            Type::DynTrait(dyn_trait) => self.check_dyn_trait(dyn_trait),
+            Type::Generic(_) => {}
+            Type::Primitive(_) => {}
+            Type::FunctionPointer(fp) => self.check_function_pointer(&**fp),
+            Type::Tuple(tys) => tys.iter().for_each(|ty| self.check_type(ty)),
+            Type::Slice(inner) => self.check_type(&**inner),
+            Type::Array { type_, len: _ } => self.check_type(&**type_),
+            Type::ImplTrait(bounds) => bounds.iter().for_each(|b| self.check_generic_bound(b)),
+            Type::Infer => {}
+            Type::RawPointer { mutable: _, type_ } => self.check_type(&**type_),
+            Type::BorrowedRef { lifetime: _, mutable: _, type_ } => self.check_type(&**type_),
+            Type::QualifiedPath { name: _, args, self_type, trait_ } => {
+                self.check_generic_args(&**args);
+                self.check_type(&**self_type);
+                self.check_path(trait_, PathKind::Trait);
+            }
+        }
+    }
+
+    fn check_fn_decl(&mut self, x: &'a FnDecl) {
+        x.inputs.iter().for_each(|(_name, ty)| self.check_type(ty));
+        if let Some(output) = &x.output {
+            self.check_type(output);
+        }
+    }
+
+    fn check_generic_bound(&mut self, x: &'a GenericBound) {
+        match x {
+            GenericBound::TraitBound { trait_, generic_params, modifier: _ } => {
+                self.check_path(trait_, PathKind::Trait);
+                generic_params.iter().for_each(|gpd| self.check_generic_param_def(gpd));
+            }
+            GenericBound::Outlives(_) => {}
+        }
+    }
+
+    fn check_path(&mut self, x: &'a Path, kind: PathKind) {
+        match kind {
+            PathKind::Trait => self.add_trait_id(&x.id),
+            PathKind::StructEnumUnion => self.add_struct_enum_union_id(&x.id),
+        }
+        if let Some(args) = &x.args {
+            self.check_generic_args(&**args);
+        }
+    }
+
+    fn check_generic_args(&mut self, x: &'a GenericArgs) {
+        match x {
+            GenericArgs::AngleBracketed { args, bindings } => {
+                args.iter().for_each(|arg| self.check_generic_arg(arg));
+                bindings.iter().for_each(|bind| self.check_type_binding(bind));
+            }
+            GenericArgs::Parenthesized { inputs, output } => {
+                inputs.iter().for_each(|ty| self.check_type(ty));
+                if let Some(o) = output {
+                    self.check_type(o);
+                }
+            }
+        }
+    }
+
+    fn check_generic_param_def(&mut self, gpd: &'a GenericParamDef) {
+        match &gpd.kind {
+            rustdoc_json_types::GenericParamDefKind::Lifetime { outlives: _ } => {}
+            rustdoc_json_types::GenericParamDefKind::Type { bounds, default, synthetic: _ } => {
+                bounds.iter().for_each(|b| self.check_generic_bound(b));
+                if let Some(ty) = default {
+                    self.check_type(ty);
+                }
+            }
+            rustdoc_json_types::GenericParamDefKind::Const { type_, default: _ } => {
+                self.check_type(type_)
+            }
+        }
+    }
+
+    fn check_generic_arg(&mut self, arg: &'a GenericArg) {
+        match arg {
+            GenericArg::Lifetime(_) => {}
+            GenericArg::Type(ty) => self.check_type(ty),
+            GenericArg::Const(c) => self.check_constant(c),
+            GenericArg::Infer => {}
+        }
+    }
+
+    fn check_type_binding(&mut self, bind: &'a TypeBinding) {
+        self.check_generic_args(&bind.args);
+        match &bind.binding {
+            TypeBindingKind::Equality(term) => self.check_term(term),
+            TypeBindingKind::Constraint(bounds) => {
+                bounds.iter().for_each(|b| self.check_generic_bound(b))
+            }
+        }
+    }
+
+    fn check_term(&mut self, term: &'a Term) {
+        match term {
+            Term::Type(ty) => self.check_type(ty),
+            Term::Constant(con) => self.check_constant(con),
+        }
+    }
+
+    fn check_where_predicate(&mut self, w: &'a WherePredicate) {
+        match w {
+            WherePredicate::BoundPredicate { type_, bounds, generic_params } => {
+                self.check_type(type_);
+                bounds.iter().for_each(|b| self.check_generic_bound(b));
+                generic_params.iter().for_each(|gpd| self.check_generic_param_def(gpd));
+            }
+            WherePredicate::RegionPredicate { lifetime: _, bounds } => {
+                bounds.iter().for_each(|b| self.check_generic_bound(b));
+            }
+            WherePredicate::EqPredicate { lhs, rhs } => {
+                self.check_type(lhs);
+                self.check_term(rhs);
+            }
+        }
+    }
+
+    fn check_dyn_trait(&mut self, dyn_trait: &'a DynTrait) {
+        for pt in &dyn_trait.traits {
+            self.check_path(&pt.trait_, PathKind::Trait);
+            pt.generic_params.iter().for_each(|gpd| self.check_generic_param_def(gpd));
+        }
+    }
+
+    fn check_function_pointer(&mut self, fp: &'a FunctionPointer) {
+        self.check_fn_decl(&fp.decl);
+        fp.generic_params.iter().for_each(|gpd| self.check_generic_param_def(gpd));
+    }
+
+    fn add_id_checked(&mut self, id: &'a Id, valid: fn(Kind) -> bool, expected: &str) {
+        if let Some(kind) = self.kind_of(id) {
+            if valid(kind) {
+                if !self.seen_ids.contains(id) {
+                    self.todo.insert(id);
+                }
+            } else {
+                self.fail_expecting(id, expected);
+            }
+        } else {
+            if !self.missing_ids.contains(id) {
+                self.missing_ids.insert(id);
+                self.fail(id, ErrorKind::NotFound)
+            }
+        }
+    }
+
+    fn add_field_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_struct_field, "StructField");
+    }
+
+    fn add_mod_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_module, "Module");
+    }
+    fn add_impl_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_impl, "Impl");
+    }
+
+    fn add_variant_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_variant, "Variant");
+    }
+
+    fn add_trait_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_trait, "Trait");
+    }
+
+    fn add_struct_enum_union_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::is_struct_enum_union, "Struct or Enum or Union");
+    }
+
+    /// Add an Id that appeared in a trait
+    fn add_trait_item_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::can_appear_in_trait, "Trait inner item");
+    }
+
+    /// Add an Id that appeared in a mod
+    fn add_mod_item_id(&mut self, id: &'a Id) {
+        self.add_id_checked(id, Kind::can_appear_in_mod, "Module inner item")
+    }
+
+    fn fail_expecting(&mut self, id: &Id, expected: &str) {
+        let kind = self.kind_of(id).unwrap(); // We know it has a kind, as it's wrong.
+        self.fail(id, ErrorKind::Custom(format!("Expected {expected} but found {kind:?}")));
+    }
+
+    fn fail(&mut self, id: &Id, kind: ErrorKind) {
+        self.errs.push(Error { id: id.clone(), kind });
+    }
+
+    fn kind_of(&mut self, id: &Id) -> Option<Kind> {
+        if let Some(item) = self.krate.index.get(id) {
+            Some(Kind::from_item(item))
+        } else if let Some(summary) = self.krate.paths.get(id) {
+            Some(Kind::from_summary(summary))
+        } else {
+            None
+        }
+    }
+}
+
+fn set_remove<T: Hash + Eq + Clone>(set: &mut HashSet<T>) -> Option<T> {
+    if let Some(id) = set.iter().next() {
+        let id = id.clone();
+        set.take(&id)
+    } else {
+        None
+    }
+}