mv compiler to compiler/

1 files changed, 1095 insertions, 0 deletions

diff --git a/compiler/rustc_save_analysis/src/lib.rs b/compiler/rustc_save_analysis/src/lib.rs
new file mode 100644
index 00000000000..629051c1820
--- /dev/null
+++ b/compiler/rustc_save_analysis/src/lib.rs
@@ -0,0 +1,1095 @@
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
+#![feature(nll)]
+#![feature(or_patterns)]
+#![recursion_limit = "256"]
+
+mod dump_visitor;
+mod dumper;
+#[macro_use]
+mod span_utils;
+mod sig;
+
+use rustc_ast as ast;
+use rustc_ast::util::comments::beautify_doc_string;
+use rustc_ast_pretty::pprust::attribute_to_string;
+use rustc_hir as hir;
+use rustc_hir::def::{DefKind as HirDefKind, Res};
+use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::Node;
+use rustc_hir_pretty::{enum_def_to_string, fn_to_string, ty_to_string};
+use rustc_middle::hir::map::Map;
+use rustc_middle::middle::cstore::ExternCrate;
+use rustc_middle::middle::privacy::AccessLevels;
+use rustc_middle::ty::{self, DefIdTree, TyCtxt};
+use rustc_middle::{bug, span_bug};
+use rustc_session::config::{CrateType, Input, OutputType};
+use rustc_session::output::{filename_for_metadata, out_filename};
+use rustc_span::source_map::Spanned;
+use rustc_span::symbol::Ident;
+use rustc_span::*;
+
+use std::cell::Cell;
+use std::default::Default;
+use std::env;
+use std::fs::File;
+use std::io::BufWriter;
+use std::path::{Path, PathBuf};
+
+use dump_visitor::DumpVisitor;
+use span_utils::SpanUtils;
+
+use rls_data::config::Config;
+use rls_data::{
+    Analysis, Def, DefKind, ExternalCrateData, GlobalCrateId, Impl, ImplKind, MacroRef, Ref,
+    RefKind, Relation, RelationKind, SpanData,
+};
+
+use tracing::{debug, error, info};
+
+pub struct SaveContext<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
+    access_levels: &'tcx AccessLevels,
+    span_utils: SpanUtils<'tcx>,
+    config: Config,
+    impl_counter: Cell<u32>,
+}
+
+#[derive(Debug)]
+pub enum Data {
+    RefData(Ref),
+    DefData(Def),
+    RelationData(Relation, Impl),
+}
+
+impl<'tcx> SaveContext<'tcx> {
+    /// Gets the type-checking results for the current body.
+    /// As this will ICE if called outside bodies, only call when working with
+    /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
+    #[track_caller]
+    fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
+        self.maybe_typeck_results.expect("`SaveContext::typeck_results` called outside of body")
+    }
+
+    fn span_from_span(&self, span: Span) -> SpanData {
+        use rls_span::{Column, Row};
+
+        let sm = self.tcx.sess.source_map();
+        let start = sm.lookup_char_pos(span.lo());
+        let end = sm.lookup_char_pos(span.hi());
+
+        SpanData {
+            file_name: start.file.name.to_string().into(),
+            byte_start: span.lo().0,
+            byte_end: span.hi().0,
+            line_start: Row::new_one_indexed(start.line as u32),
+            line_end: Row::new_one_indexed(end.line as u32),
+            column_start: Column::new_one_indexed(start.col.0 as u32 + 1),
+            column_end: Column::new_one_indexed(end.col.0 as u32 + 1),
+        }
+    }
+
+    // Returns path to the compilation output (e.g., libfoo-12345678.rmeta)
+    pub fn compilation_output(&self, crate_name: &str) -> PathBuf {
+        let sess = &self.tcx.sess;
+        // Save-analysis is emitted per whole session, not per each crate type
+        let crate_type = sess.crate_types()[0];
+        let outputs = &*self.tcx.output_filenames(LOCAL_CRATE);
+
+        if outputs.outputs.contains_key(&OutputType::Metadata) {
+            filename_for_metadata(sess, crate_name, outputs)
+        } else if outputs.outputs.should_codegen() {
+            out_filename(sess, crate_type, outputs, crate_name)
+        } else {
+            // Otherwise it's only a DepInfo, in which case we return early and
+            // not even reach the analysis stage.
+            unreachable!()
+        }
+    }
+
+    // List external crates used by the current crate.
+    pub fn get_external_crates(&self) -> Vec<ExternalCrateData> {
+        let mut result = Vec::with_capacity(self.tcx.crates().len());
+
+        for &n in self.tcx.crates().iter() {
+            let span = match self.tcx.extern_crate(n.as_def_id()) {
+                Some(&ExternCrate { span, .. }) => span,
+                None => {
+                    debug!("skipping crate {}, no data", n);
+                    continue;
+                }
+            };
+            let lo_loc = self.span_utils.sess.source_map().lookup_char_pos(span.lo());
+            result.push(ExternalCrateData {
+                // FIXME: change file_name field to PathBuf in rls-data
+                // https://github.com/nrc/rls-data/issues/7
+                file_name: self.span_utils.make_filename_string(&lo_loc.file),
+                num: n.as_u32(),
+                id: GlobalCrateId {
+                    name: self.tcx.crate_name(n).to_string(),
+                    disambiguator: self.tcx.crate_disambiguator(n).to_fingerprint().as_value(),
+                },
+            });
+        }
+
+        result
+    }
+
+    pub fn get_extern_item_data(&self, item: &hir::ForeignItem<'_>) -> Option<Data> {
+        let def_id = self.tcx.hir().local_def_id(item.hir_id).to_def_id();
+        let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+        match item.kind {
+            hir::ForeignItemKind::Fn(ref decl, arg_names, ref generics) => {
+                filter!(self.span_utils, item.ident.span);
+
+                Some(Data::DefData(Def {
+                    kind: DefKind::ForeignFunction,
+                    id: id_from_def_id(def_id),
+                    span: self.span_from_span(item.ident.span),
+                    name: item.ident.to_string(),
+                    qualname,
+                    value: fn_to_string(
+                        decl,
+                        hir::FnHeader {
+                            // functions in extern block are implicitly unsafe
+                            unsafety: hir::Unsafety::Unsafe,
+                            // functions in extern block cannot be const
+                            constness: hir::Constness::NotConst,
+                            abi: self.tcx.hir().get_foreign_abi(item.hir_id),
+                            // functions in extern block cannot be async
+                            asyncness: hir::IsAsync::NotAsync,
+                        },
+                        Some(item.ident.name),
+                        generics,
+                        &item.vis,
+                        arg_names,
+                        None,
+                    ),
+                    parent: None,
+                    children: vec![],
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::foreign_item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ForeignItemKind::Static(ref ty, _) => {
+                filter!(self.span_utils, item.ident.span);
+
+                let id = id_from_def_id(def_id);
+                let span = self.span_from_span(item.ident.span);
+
+                Some(Data::DefData(Def {
+                    kind: DefKind::ForeignStatic,
+                    id,
+                    span,
+                    name: item.ident.to_string(),
+                    qualname,
+                    value: ty_to_string(ty),
+                    parent: None,
+                    children: vec![],
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::foreign_item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            // FIXME(plietar): needs a new DefKind in rls-data
+            hir::ForeignItemKind::Type => None,
+        }
+    }
+
+    pub fn get_item_data(&self, item: &hir::Item<'_>) -> Option<Data> {
+        let def_id = self.tcx.hir().local_def_id(item.hir_id).to_def_id();
+        match item.kind {
+            hir::ItemKind::Fn(ref sig, ref generics, _) => {
+                let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+                filter!(self.span_utils, item.ident.span);
+                Some(Data::DefData(Def {
+                    kind: DefKind::Function,
+                    id: id_from_def_id(def_id),
+                    span: self.span_from_span(item.ident.span),
+                    name: item.ident.to_string(),
+                    qualname,
+                    value: fn_to_string(
+                        sig.decl,
+                        sig.header,
+                        Some(item.ident.name),
+                        generics,
+                        &item.vis,
+                        &[],
+                        None,
+                    ),
+                    parent: None,
+                    children: vec![],
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ItemKind::Static(ref typ, ..) => {
+                let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+
+                filter!(self.span_utils, item.ident.span);
+
+                let id = id_from_def_id(def_id);
+                let span = self.span_from_span(item.ident.span);
+
+                Some(Data::DefData(Def {
+                    kind: DefKind::Static,
+                    id,
+                    span,
+                    name: item.ident.to_string(),
+                    qualname,
+                    value: ty_to_string(&typ),
+                    parent: None,
+                    children: vec![],
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ItemKind::Const(ref typ, _) => {
+                let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+                filter!(self.span_utils, item.ident.span);
+
+                let id = id_from_def_id(def_id);
+                let span = self.span_from_span(item.ident.span);
+
+                Some(Data::DefData(Def {
+                    kind: DefKind::Const,
+                    id,
+                    span,
+                    name: item.ident.to_string(),
+                    qualname,
+                    value: ty_to_string(typ),
+                    parent: None,
+                    children: vec![],
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ItemKind::Mod(ref m) => {
+                let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+
+                let sm = self.tcx.sess.source_map();
+                let filename = sm.span_to_filename(m.inner);
+
+                filter!(self.span_utils, item.ident.span);
+
+                Some(Data::DefData(Def {
+                    kind: DefKind::Mod,
+                    id: id_from_def_id(def_id),
+                    name: item.ident.to_string(),
+                    qualname,
+                    span: self.span_from_span(item.ident.span),
+                    value: filename.to_string(),
+                    parent: None,
+                    children: m.item_ids.iter().map(|i| id_from_hir_id(i.id, self)).collect(),
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ItemKind::Enum(ref def, ref generics) => {
+                let name = item.ident.to_string();
+                let qualname = format!("::{}", self.tcx.def_path_str(def_id));
+                filter!(self.span_utils, item.ident.span);
+                let value =
+                    enum_def_to_string(def, generics, item.ident.name, item.span, &item.vis);
+                Some(Data::DefData(Def {
+                    kind: DefKind::Enum,
+                    id: id_from_def_id(def_id),
+                    span: self.span_from_span(item.ident.span),
+                    name,
+                    qualname,
+                    value,
+                    parent: None,
+                    children: def.variants.iter().map(|v| id_from_hir_id(v.id, self)).collect(),
+                    decl_id: None,
+                    docs: self.docs_for_attrs(&item.attrs),
+                    sig: sig::item_signature(item, self),
+                    attributes: lower_attributes(item.attrs.to_vec(), self),
+                }))
+            }
+            hir::ItemKind::Impl { ref of_trait, ref self_ty, ref items, .. } => {
+                if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = self_ty.kind {
+                    // Common case impl for a struct or something basic.
+                    if generated_code(path.span) {
+                        return None;
+                    }
+                    let sub_span = path.segments.last().unwrap().ident.span;
+                    filter!(self.span_utils, sub_span);
+
+                    let impl_id = self.next_impl_id();
+                    let span = self.span_from_span(sub_span);
+
+                    let type_data = self.lookup_def_id(self_ty.hir_id);
+                    type_data.map(|type_data| {
+                        Data::RelationData(
+                            Relation {
+                                kind: RelationKind::Impl { id: impl_id },
+                                span: span.clone(),
+                                from: id_from_def_id(type_data),
+                                to: of_trait
+                                    .as_ref()
+                                    .and_then(|t| self.lookup_def_id(t.hir_ref_id))
+                                    .map(id_from_def_id)
+                                    .unwrap_or_else(null_id),
+                            },
+                            Impl {
+                                id: impl_id,
+                                kind: match *of_trait {
+                                    Some(_) => ImplKind::Direct,
+                                    None => ImplKind::Inherent,
+                                },
+                                span,
+                                value: String::new(),
+                                parent: None,
+                                children: items
+                                    .iter()
+                                    .map(|i| id_from_hir_id(i.id.hir_id, self))
+                                    .collect(),
+                                docs: String::new(),
+                                sig: None,
+                                attributes: vec![],
+                            },
+                        )
+                    })
+                } else {
+                    None
+                }
+            }
+            _ => {
+                // FIXME
+                bug!();
+            }
+        }
+    }
+
+    pub fn get_field_data(&self, field: &hir::StructField<'_>, scope: hir::HirId) -> Option<Def> {
+        let name = field.ident.to_string();
+        let scope_def_id = self.tcx.hir().local_def_id(scope).to_def_id();
+        let qualname = format!("::{}::{}", self.tcx.def_path_str(scope_def_id), field.ident);
+        filter!(self.span_utils, field.ident.span);
+        let field_def_id = self.tcx.hir().local_def_id(field.hir_id).to_def_id();
+        let typ = self.tcx.type_of(field_def_id).to_string();
+
+        let id = id_from_def_id(field_def_id);
+        let span = self.span_from_span(field.ident.span);
+
+        Some(Def {
+            kind: DefKind::Field,
+            id,
+            span,
+            name,
+            qualname,
+            value: typ,
+            parent: Some(id_from_def_id(scope_def_id)),
+            children: vec![],
+            decl_id: None,
+            docs: self.docs_for_attrs(&field.attrs),
+            sig: sig::field_signature(field, self),
+            attributes: lower_attributes(field.attrs.to_vec(), self),
+        })
+    }
+
+    // FIXME would be nice to take a MethodItem here, but the ast provides both
+    // trait and impl flavours, so the caller must do the disassembly.
+    pub fn get_method_data(&self, hir_id: hir::HirId, ident: Ident, span: Span) -> Option<Def> {
+        // The qualname for a method is the trait name or name of the struct in an impl in
+        // which the method is declared in, followed by the method's name.
+        let def_id = self.tcx.hir().local_def_id(hir_id).to_def_id();
+        let (qualname, parent_scope, decl_id, docs, attributes) =
+            match self.tcx.impl_of_method(def_id) {
+                Some(impl_id) => match self.tcx.hir().get_if_local(impl_id) {
+                    Some(Node::Item(item)) => match item.kind {
+                        hir::ItemKind::Impl { ref self_ty, .. } => {
+                            let hir = self.tcx.hir();
+
+                            let mut qualname = String::from("<");
+                            qualname
+                                .push_str(&rustc_hir_pretty::id_to_string(&hir, self_ty.hir_id));
+
+                            let trait_id = self.tcx.trait_id_of_impl(impl_id);
+                            let mut docs = String::new();
+                            let mut attrs = vec![];
+                            if let Some(Node::ImplItem(item)) = hir.find(hir_id) {
+                                docs = self.docs_for_attrs(&item.attrs);
+                                attrs = item.attrs.to_vec();
+                            }
+
+                            let mut decl_id = None;
+                            if let Some(def_id) = trait_id {
+                                // A method in a trait impl.
+                                qualname.push_str(" as ");
+                                qualname.push_str(&self.tcx.def_path_str(def_id));
+
+                                decl_id = self
+                                    .tcx
+                                    .associated_items(def_id)
+                                    .filter_by_name_unhygienic(ident.name)
+                                    .next()
+                                    .map(|item| item.def_id);
+                            }
+                            qualname.push_str(">");
+
+                            (qualname, trait_id, decl_id, docs, attrs)
+                        }
+                        _ => {
+                            span_bug!(
+                                span,
+                                "Container {:?} for method {} not an impl?",
+                                impl_id,
+                                hir_id
+                            );
+                        }
+                    },
+                    r => {
+                        span_bug!(
+                            span,
+                            "Container {:?} for method {} is not a node item {:?}",
+                            impl_id,
+                            hir_id,
+                            r
+                        );
+                    }
+                },
+                None => match self.tcx.trait_of_item(def_id) {
+                    Some(def_id) => {
+                        let mut docs = String::new();
+                        let mut attrs = vec![];
+
+                        if let Some(Node::TraitItem(item)) = self.tcx.hir().find(hir_id) {
+                            docs = self.docs_for_attrs(&item.attrs);
+                            attrs = item.attrs.to_vec();
+                        }
+
+                        (
+                            format!("::{}", self.tcx.def_path_str(def_id)),
+                            Some(def_id),
+                            None,
+                            docs,
+                            attrs,
+                        )
+                    }
+                    None => {
+                        debug!("could not find container for method {} at {:?}", hir_id, span);
+                        // This is not necessarily a bug, if there was a compilation error,
+                        // the typeck results we need might not exist.
+                        return None;
+                    }
+                },
+            };
+
+        let qualname = format!("{}::{}", qualname, ident.name);
+
+        filter!(self.span_utils, ident.span);
+
+        Some(Def {
+            kind: DefKind::Method,
+            id: id_from_def_id(def_id),
+            span: self.span_from_span(ident.span),
+            name: ident.name.to_string(),
+            qualname,
+            // FIXME you get better data here by using the visitor.
+            value: String::new(),
+            parent: parent_scope.map(id_from_def_id),
+            children: vec![],
+            decl_id: decl_id.map(id_from_def_id),
+            docs,
+            sig: None,
+            attributes: lower_attributes(attributes, self),
+        })
+    }
+
+    pub fn get_trait_ref_data(&self, trait_ref: &hir::TraitRef<'_>) -> Option<Ref> {
+        self.lookup_def_id(trait_ref.hir_ref_id).and_then(|def_id| {
+            let span = trait_ref.path.span;
+            if generated_code(span) {
+                return None;
+            }
+            let sub_span = trait_ref.path.segments.last().unwrap().ident.span;
+            filter!(self.span_utils, sub_span);
+            let span = self.span_from_span(sub_span);
+            Some(Ref { kind: RefKind::Type, span, ref_id: id_from_def_id(def_id) })
+        })
+    }
+
+    pub fn get_expr_data(&self, expr: &hir::Expr<'_>) -> Option<Data> {
+        let ty = self.typeck_results().expr_ty_adjusted_opt(expr)?;
+        if matches!(ty.kind, ty::Error(_)) {
+            return None;
+        }
+        match expr.kind {
+            hir::ExprKind::Field(ref sub_ex, ident) => {
+                match self.typeck_results().expr_ty_adjusted(&sub_ex).kind {
+                    ty::Adt(def, _) if !def.is_enum() => {
+                        let variant = &def.non_enum_variant();
+                        filter!(self.span_utils, ident.span);
+                        let span = self.span_from_span(ident.span);
+                        Some(Data::RefData(Ref {
+                            kind: RefKind::Variable,
+                            span,
+                            ref_id: self
+                                .tcx
+                                .find_field_index(ident, variant)
+                                .map(|index| id_from_def_id(variant.fields[index].did))
+                                .unwrap_or_else(null_id),
+                        }))
+                    }
+                    ty::Tuple(..) => None,
+                    _ => {
+                        debug!("expected struct or union type, found {:?}", ty);
+                        None
+                    }
+                }
+            }
+            hir::ExprKind::Struct(qpath, ..) => match ty.kind {
+                ty::Adt(def, _) => {
+                    let sub_span = qpath.last_segment_span();
+                    filter!(self.span_utils, sub_span);
+                    let span = self.span_from_span(sub_span);
+                    Some(Data::RefData(Ref {
+                        kind: RefKind::Type,
+                        span,
+                        ref_id: id_from_def_id(def.did),
+                    }))
+                }
+                _ => {
+                    debug!("expected adt, found {:?}", ty);
+                    None
+                }
+            },
+            hir::ExprKind::MethodCall(ref seg, ..) => {
+                let method_id = match self.typeck_results().type_dependent_def_id(expr.hir_id) {
+                    Some(id) => id,
+                    None => {
+                        debug!("could not resolve method id for {:?}", expr);
+                        return None;
+                    }
+                };
+                let (def_id, decl_id) = match self.tcx.associated_item(method_id).container {
+                    ty::ImplContainer(_) => (Some(method_id), None),
+                    ty::TraitContainer(_) => (None, Some(method_id)),
+                };
+                let sub_span = seg.ident.span;
+                filter!(self.span_utils, sub_span);
+                let span = self.span_from_span(sub_span);
+                Some(Data::RefData(Ref {
+                    kind: RefKind::Function,
+                    span,
+                    ref_id: def_id.or(decl_id).map(id_from_def_id).unwrap_or_else(null_id),
+                }))
+            }
+            hir::ExprKind::Path(ref path) => {
+                self.get_path_data(expr.hir_id, path).map(Data::RefData)
+            }
+            _ => {
+                // FIXME
+                bug!("invalid expression: {:?}", expr);
+            }
+        }
+    }
+
+    pub fn get_path_res(&self, hir_id: hir::HirId) -> Res {
+        match self.tcx.hir().get(hir_id) {
+            Node::TraitRef(tr) => tr.path.res,
+
+            Node::Item(&hir::Item { kind: hir::ItemKind::Use(path, _), .. }) => path.res,
+            Node::Visibility(&Spanned {
+                node: hir::VisibilityKind::Restricted { ref path, .. },
+                ..
+            }) => path.res,
+
+            Node::PathSegment(seg) => match seg.res {
+                Some(res) if res != Res::Err => res,
+                _ => {
+                    let parent_node = self.tcx.hir().get_parent_node(hir_id);
+                    self.get_path_res(parent_node)
+                }
+            },
+
+            Node::Expr(&hir::Expr { kind: hir::ExprKind::Struct(ref qpath, ..), .. }) => {
+                self.typeck_results().qpath_res(qpath, hir_id)
+            }
+
+            Node::Expr(&hir::Expr { kind: hir::ExprKind::Path(ref qpath), .. })
+            | Node::Pat(&hir::Pat {
+                kind:
+                    hir::PatKind::Path(ref qpath)
+                    | hir::PatKind::Struct(ref qpath, ..)
+                    | hir::PatKind::TupleStruct(ref qpath, ..),
+                ..
+            })
+            | Node::Ty(&hir::Ty { kind: hir::TyKind::Path(ref qpath), .. }) => match qpath {
+                hir::QPath::Resolved(_, path) => path.res,
+                hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
+                    .maybe_typeck_results
+                    .map_or(Res::Err, |typeck_results| typeck_results.qpath_res(qpath, hir_id)),
+            },
+
+            Node::Binding(&hir::Pat {
+                kind: hir::PatKind::Binding(_, canonical_id, ..), ..
+            }) => Res::Local(canonical_id),
+
+            _ => Res::Err,
+        }
+    }
+
+    pub fn get_path_data(&self, id: hir::HirId, path: &hir::QPath<'_>) -> Option<Ref> {
+        let segment = match path {
+            hir::QPath::Resolved(_, path) => path.segments.last(),
+            hir::QPath::TypeRelative(_, segment) => Some(*segment),
+            hir::QPath::LangItem(..) => None,
+        };
+        segment.and_then(|seg| {
+            self.get_path_segment_data(seg).or_else(|| self.get_path_segment_data_with_id(seg, id))
+        })
+    }
+
+    pub fn get_path_segment_data(&self, path_seg: &hir::PathSegment<'_>) -> Option<Ref> {
+        self.get_path_segment_data_with_id(path_seg, path_seg.hir_id?)
+    }
+
+    pub fn get_path_segment_data_with_id(
+        &self,
+        path_seg: &hir::PathSegment<'_>,
+        id: hir::HirId,
+    ) -> Option<Ref> {
+        // Returns true if the path is function type sugar, e.g., `Fn(A) -> B`.
+        fn fn_type(seg: &hir::PathSegment<'_>) -> bool {
+            seg.args.map(|args| args.parenthesized).unwrap_or(false)
+        }
+
+        let res = self.get_path_res(id);
+        let span = path_seg.ident.span;
+        filter!(self.span_utils, span);
+        let span = self.span_from_span(span);
+
+        match res {
+            Res::Local(id) => {
+                Some(Ref { kind: RefKind::Variable, span, ref_id: id_from_hir_id(id, self) })
+            }
+            Res::Def(HirDefKind::Trait, def_id) if fn_type(path_seg) => {
+                Some(Ref { kind: RefKind::Type, span, ref_id: id_from_def_id(def_id) })
+            }
+            Res::Def(
+                HirDefKind::Struct
+                | HirDefKind::Variant
+                | HirDefKind::Union
+                | HirDefKind::Enum
+                | HirDefKind::TyAlias
+                | HirDefKind::ForeignTy
+                | HirDefKind::TraitAlias
+                | HirDefKind::AssocTy
+                | HirDefKind::Trait
+                | HirDefKind::OpaqueTy
+                | HirDefKind::TyParam,
+                def_id,
+            ) => Some(Ref { kind: RefKind::Type, span, ref_id: id_from_def_id(def_id) }),
+            Res::Def(HirDefKind::ConstParam, def_id) => {
+                Some(Ref { kind: RefKind::Variable, span, ref_id: id_from_def_id(def_id) })
+            }
+            Res::Def(HirDefKind::Ctor(..), def_id) => {
+                // This is a reference to a tuple struct or an enum variant where the def_id points
+                // to an invisible constructor function. That is not a very useful
+                // def, so adjust to point to the tuple struct or enum variant itself.
+                let parent_def_id = self.tcx.parent(def_id).unwrap();
+                Some(Ref { kind: RefKind::Type, span, ref_id: id_from_def_id(parent_def_id) })
+            }
+            Res::Def(HirDefKind::Static | HirDefKind::Const | HirDefKind::AssocConst, _) => {
+                Some(Ref { kind: RefKind::Variable, span, ref_id: id_from_def_id(res.def_id()) })
+            }
+            Res::Def(HirDefKind::AssocFn, decl_id) => {
+                let def_id = if decl_id.is_local() {
+                    let ti = self.tcx.associated_item(decl_id);
+
+                    self.tcx
+                        .associated_items(ti.container.id())
+                        .filter_by_name_unhygienic(ti.ident.name)
+                        .find(|item| item.defaultness.has_value())
+                        .map(|item| item.def_id)
+                } else {
+                    None
+                };
+                Some(Ref {
+                    kind: RefKind::Function,
+                    span,
+                    ref_id: id_from_def_id(def_id.unwrap_or(decl_id)),
+                })
+            }
+            Res::Def(HirDefKind::Fn, def_id) => {
+                Some(Ref { kind: RefKind::Function, span, ref_id: id_from_def_id(def_id) })
+            }
+            Res::Def(HirDefKind::Mod, def_id) => {
+                Some(Ref { kind: RefKind::Mod, span, ref_id: id_from_def_id(def_id) })
+            }
+
+            Res::Def(
+                HirDefKind::Macro(..)
+                | HirDefKind::ExternCrate
+                | HirDefKind::ForeignMod
+                | HirDefKind::LifetimeParam
+                | HirDefKind::AnonConst
+                | HirDefKind::Use
+                | HirDefKind::Field
+                | HirDefKind::GlobalAsm
+                | HirDefKind::Impl
+                | HirDefKind::Closure
+                | HirDefKind::Generator,
+                _,
+            )
+            | Res::PrimTy(..)
+            | Res::SelfTy(..)
+            | Res::ToolMod
+            | Res::NonMacroAttr(..)
+            | Res::SelfCtor(..)
+            | Res::Err => None,
+        }
+    }
+
+    pub fn get_field_ref_data(
+        &self,
+        field_ref: &hir::Field<'_>,
+        variant: &ty::VariantDef,
+    ) -> Option<Ref> {
+        filter!(self.span_utils, field_ref.ident.span);
+        self.tcx.find_field_index(field_ref.ident, variant).map(|index| {
+            let span = self.span_from_span(field_ref.ident.span);
+            Ref { kind: RefKind::Variable, span, ref_id: id_from_def_id(variant.fields[index].did) }
+        })
+    }
+
+    /// Attempt to return MacroRef for any AST node.
+    ///
+    /// For a given piece of AST defined by the supplied Span and NodeId,
+    /// returns `None` if the node is not macro-generated or the span is malformed,
+    /// else uses the expansion callsite and callee to return some MacroRef.
+    pub fn get_macro_use_data(&self, span: Span) -> Option<MacroRef> {
+        if !generated_code(span) {
+            return None;
+        }
+        // Note we take care to use the source callsite/callee, to handle
+        // nested expansions and ensure we only generate data for source-visible
+        // macro uses.
+        let callsite = span.source_callsite();
+        let callsite_span = self.span_from_span(callsite);
+        let callee = span.source_callee()?;
+
+        let mac_name = match callee.kind {
+            ExpnKind::Macro(kind, name) => match kind {
+                MacroKind::Bang => name,
+
+                // Ignore attribute macros, their spans are usually mangled
+                // FIXME(eddyb) is this really the case anymore?
+                MacroKind::Attr | MacroKind::Derive => return None,
+            },
+
+            // These are not macros.
+            // FIXME(eddyb) maybe there is a way to handle them usefully?
+            ExpnKind::Root | ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => return None,
+        };
+
+        let callee_span = self.span_from_span(callee.def_site);
+        Some(MacroRef {
+            span: callsite_span,
+            qualname: mac_name.to_string(), // FIXME: generate the real qualname
+            callee_span,
+        })
+    }
+
+    fn lookup_def_id(&self, ref_id: hir::HirId) -> Option<DefId> {
+        match self.get_path_res(ref_id) {
+            Res::PrimTy(_) | Res::SelfTy(..) | Res::Err => None,
+            def => def.opt_def_id(),
+        }
+    }
+
+    fn docs_for_attrs(&self, attrs: &[ast::Attribute]) -> String {
+        let mut result = String::new();
+
+        for attr in attrs {
+            if let Some(val) = attr.doc_str() {
+                // FIXME: Should save-analysis beautify doc strings itself or leave it to users?
+                result.push_str(&beautify_doc_string(val));
+                result.push('\n');
+            } else if self.tcx.sess.check_name(attr, sym::doc) {
+                if let Some(meta_list) = attr.meta_item_list() {
+                    meta_list
+                        .into_iter()
+                        .filter(|it| it.has_name(sym::include))
+                        .filter_map(|it| it.meta_item_list().map(|l| l.to_owned()))
+                        .flat_map(|it| it)
+                        .filter(|meta| meta.has_name(sym::contents))
+                        .filter_map(|meta| meta.value_str())
+                        .for_each(|val| {
+                            result.push_str(&val.as_str());
+                            result.push('\n');
+                        });
+                }
+            }
+        }
+
+        if !self.config.full_docs {
+            if let Some(index) = result.find("\n\n") {
+                result.truncate(index);
+            }
+        }
+
+        result
+    }
+
+    fn next_impl_id(&self) -> u32 {
+        let next = self.impl_counter.get();
+        self.impl_counter.set(next + 1);
+        next
+    }
+}
+
+// An AST visitor for collecting paths (e.g., the names of structs) and formal
+// variables (idents) from patterns.
+struct PathCollector<'l> {
+    tcx: TyCtxt<'l>,
+    collected_paths: Vec<(hir::HirId, &'l hir::QPath<'l>)>,
+    collected_idents: Vec<(hir::HirId, Ident, hir::Mutability)>,
+}
+
+impl<'l> PathCollector<'l> {
+    fn new(tcx: TyCtxt<'l>) -> PathCollector<'l> {
+        PathCollector { tcx, collected_paths: vec![], collected_idents: vec![] }
+    }
+}
+
+impl<'l> Visitor<'l> for PathCollector<'l> {
+    type Map = Map<'l>;
+
+    fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
+        intravisit::NestedVisitorMap::All(self.tcx.hir())
+    }
+
+    fn visit_pat(&mut self, p: &'l hir::Pat<'l>) {
+        match p.kind {
+            hir::PatKind::Struct(ref path, ..) => {
+                self.collected_paths.push((p.hir_id, path));
+            }
+            hir::PatKind::TupleStruct(ref path, ..) | hir::PatKind::Path(ref path) => {
+                self.collected_paths.push((p.hir_id, path));
+            }
+            hir::PatKind::Binding(bm, _, ident, _) => {
+                debug!(
+                    "PathCollector, visit ident in pat {}: {:?} {:?}",
+                    ident, p.span, ident.span
+                );
+                let immut = match bm {
+                    // Even if the ref is mut, you can't change the ref, only
+                    // the data pointed at, so showing the initialising expression
+                    // is still worthwhile.
+                    hir::BindingAnnotation::Unannotated | hir::BindingAnnotation::Ref => {
+                        hir::Mutability::Not
+                    }
+                    hir::BindingAnnotation::Mutable | hir::BindingAnnotation::RefMut => {
+                        hir::Mutability::Mut
+                    }
+                };
+                self.collected_idents.push((p.hir_id, ident, immut));
+            }
+            _ => {}
+        }
+        intravisit::walk_pat(self, p);
+    }
+}
+
+/// Defines what to do with the results of saving the analysis.
+pub trait SaveHandler {
+    fn save(&mut self, save_ctxt: &SaveContext<'_>, analysis: &Analysis);
+}
+
+/// Dump the save-analysis results to a file.
+pub struct DumpHandler<'a> {
+    odir: Option<&'a Path>,
+    cratename: String,
+}
+
+impl<'a> DumpHandler<'a> {
+    pub fn new(odir: Option<&'a Path>, cratename: &str) -> DumpHandler<'a> {
+        DumpHandler { odir, cratename: cratename.to_owned() }
+    }
+
+    fn output_file(&self, ctx: &SaveContext<'_>) -> (BufWriter<File>, PathBuf) {
+        let sess = &ctx.tcx.sess;
+        let file_name = match ctx.config.output_file {
+            Some(ref s) => PathBuf::from(s),
+            None => {
+                let mut root_path = match self.odir {
+                    Some(val) => val.join("save-analysis"),
+                    None => PathBuf::from("save-analysis-temp"),
+                };
+
+                if let Err(e) = std::fs::create_dir_all(&root_path) {
+                    error!("Could not create directory {}: {}", root_path.display(), e);
+                }
+
+                let executable = sess.crate_types().iter().any(|ct| *ct == CrateType::Executable);
+                let mut out_name = if executable { String::new() } else { "lib".to_owned() };
+                out_name.push_str(&self.cratename);
+                out_name.push_str(&sess.opts.cg.extra_filename);
+                out_name.push_str(".json");
+                root_path.push(&out_name);
+
+                root_path
+            }
+        };
+
+        info!("Writing output to {}", file_name.display());
+
+        let output_file = BufWriter::new(File::create(&file_name).unwrap_or_else(|e| {
+            sess.fatal(&format!("Could not open {}: {}", file_name.display(), e))
+        }));
+
+        (output_file, file_name)
+    }
+}
+
+impl SaveHandler for DumpHandler<'_> {
+    fn save(&mut self, save_ctxt: &SaveContext<'_>, analysis: &Analysis) {
+        let sess = &save_ctxt.tcx.sess;
+        let (output, file_name) = self.output_file(&save_ctxt);
+        if let Err(e) = serde_json::to_writer(output, &analysis) {
+            error!("Can't serialize save-analysis: {:?}", e);
+        }
+
+        if sess.opts.json_artifact_notifications {
+            sess.parse_sess.span_diagnostic.emit_artifact_notification(&file_name, "save-analysis");
+        }
+    }
+}
+
+/// Call a callback with the results of save-analysis.
+pub struct CallbackHandler<'b> {
+    pub callback: &'b mut dyn FnMut(&rls_data::Analysis),
+}
+
+impl SaveHandler for CallbackHandler<'_> {
+    fn save(&mut self, _: &SaveContext<'_>, analysis: &Analysis) {
+        (self.callback)(analysis)
+    }
+}
+
+pub fn process_crate<'l, 'tcx, H: SaveHandler>(
+    tcx: TyCtxt<'tcx>,
+    cratename: &str,
+    input: &'l Input,
+    config: Option<Config>,
+    mut handler: H,
+) {
+    tcx.dep_graph.with_ignore(|| {
+        info!("Dumping crate {}", cratename);
+
+        // Privacy checking requires and is done after type checking; use a
+        // fallback in case the access levels couldn't have been correctly computed.
+        let access_levels = match tcx.sess.compile_status() {
+            Ok(..) => tcx.privacy_access_levels(LOCAL_CRATE),
+            Err(..) => tcx.arena.alloc(AccessLevels::default()),
+        };
+
+        let save_ctxt = SaveContext {
+            tcx,
+            maybe_typeck_results: None,
+            access_levels: &access_levels,
+            span_utils: SpanUtils::new(&tcx.sess),
+            config: find_config(config),
+            impl_counter: Cell::new(0),
+        };
+
+        let mut visitor = DumpVisitor::new(save_ctxt);
+
+        visitor.dump_crate_info(cratename, tcx.hir().krate());
+        visitor.dump_compilation_options(input, cratename);
+        visitor.process_crate(tcx.hir().krate());
+
+        handler.save(&visitor.save_ctxt, &visitor.analysis())
+    })
+}
+
+fn find_config(supplied: Option<Config>) -> Config {
+    if let Some(config) = supplied {
+        return config;
+    }
+
+    match env::var_os("RUST_SAVE_ANALYSIS_CONFIG") {
+        None => Config::default(),
+        Some(config) => config
+            .to_str()
+            .ok_or(())
+            .map_err(|_| error!("`RUST_SAVE_ANALYSIS_CONFIG` isn't UTF-8"))
+            .and_then(|cfg| {
+                serde_json::from_str(cfg)
+                    .map_err(|_| error!("Could not deserialize save-analysis config"))
+            })
+            .unwrap_or_default(),
+    }
+}
+
+// Utility functions for the module.
+
+// Helper function to escape quotes in a string
+fn escape(s: String) -> String {
+    s.replace("\"", "\"\"")
+}
+
+// Helper function to determine if a span came from a
+// macro expansion or syntax extension.
+fn generated_code(span: Span) -> bool {
+    span.from_expansion() || span.is_dummy()
+}
+
+// DefId::index is a newtype and so the JSON serialisation is ugly. Therefore
+// we use our own Id which is the same, but without the newtype.
+fn id_from_def_id(id: DefId) -> rls_data::Id {
+    rls_data::Id { krate: id.krate.as_u32(), index: id.index.as_u32() }
+}
+
+fn id_from_hir_id(id: hir::HirId, scx: &SaveContext<'_>) -> rls_data::Id {
+    let def_id = scx.tcx.hir().opt_local_def_id(id);
+    def_id.map(|id| id_from_def_id(id.to_def_id())).unwrap_or_else(|| {
+        // Create a *fake* `DefId` out of a `HirId` by combining the owner
+        // `local_def_index` and the `local_id`.
+        // This will work unless you have *billions* of definitions in a single
+        // crate (very unlikely to actually happen).
+        rls_data::Id {
+            krate: LOCAL_CRATE.as_u32(),
+            index: id.owner.local_def_index.as_u32() | id.local_id.as_u32().reverse_bits(),
+        }
+    })
+}
+
+fn null_id() -> rls_data::Id {
+    rls_data::Id { krate: u32::MAX, index: u32::MAX }
+}
+
+fn lower_attributes(attrs: Vec<ast::Attribute>, scx: &SaveContext<'_>) -> Vec<rls_data::Attribute> {
+    attrs
+        .into_iter()
+        // Only retain real attributes. Doc comments are lowered separately.
+        .filter(|attr| !attr.has_name(sym::doc))
+        .map(|mut attr| {
+            // Remove the surrounding '#[..]' or '#![..]' of the pretty printed
+            // attribute. First normalize all inner attribute (#![..]) to outer
+            // ones (#[..]), then remove the two leading and the one trailing character.
+            attr.style = ast::AttrStyle::Outer;
+            let value = attribute_to_string(&attr);
+            // This str slicing works correctly, because the leading and trailing characters
+            // are in the ASCII range and thus exactly one byte each.
+            let value = value[2..value.len() - 1].to_string();
+
+            rls_data::Attribute { value, span: scx.span_from_span(attr.span) }
+        })
+        .collect()
+}