Merge #6750

6750: Remove documentation query, move doc handling to attributes r=matklad a=Veykril

Fixes #3182

Removes the documentation query in favor of `Attrs::docs`. Attrs already handlded doc comments partially but the alloc saving check was wrong so it only worked when other attributes existed as well. Unfortunately the `new` constructor has to do an intermediate allocation now because we need to keep the order of mixed doc attributes and doc comments.

I've also partially adjusted the `hover` module to have its tests check the changes, it still has some `HasSource` trait usage due to the `ShortLabel` trait usage, as that is only implemented on the Ast parts and not the Hir, should this ideally be implemented for the Hir types as well?(would be a follow up PR of course)

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

Author: bors[bot]

crates/hir/src/attrs.rs

@@ -1,6 +1,9 @@
 //! Attributes & documentation for hir types.
 use hir_def::{
-    attr::Attrs, docs::Documentation, path::ModPath, resolver::HasResolver, AttrDefId, ModuleDefId,
+    attr::{Attrs, Documentation},
+    path::ModPath,
+    resolver::HasResolver,
+    AttrDefId, ModuleDefId,
 };
 use hir_expand::hygiene::Hygiene;
 use hir_ty::db::HirDatabase;
@@ -38,7 +41,7 @@ macro_rules! impl_has_attrs {
             }
             fn docs(self, db: &dyn HirDatabase) -> Option<Documentation> {
                 let def = AttrDefId::$def_id(self.into());
-                db.documentation(def)
+                db.attrs(def).docs()
             }
             fn resolve_doc_path(self, db: &dyn HirDatabase, link: &str, ns: Option<Namespace>) -> Option<ModuleDef> {
                 let def = AttrDefId::$def_id(self.into());

crates/hir/src/db.rs

@@ -2,12 +2,12 @@
 
 pub use hir_def::db::{
     AttrsQuery, BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQueryQuery,
-    CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery,
-    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery,
-    InternConstQuery, InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery,
-    InternImplQuery, InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery,
-    InternUnionQuery, ItemTreeQuery, LangItemQuery, ModuleLangItemsQuery, StaticDataQuery,
-    StructDataQuery, TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
+    CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, EnumDataQuery, ExprScopesQuery,
+    FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery, InternConstQuery,
+    InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery, InternImplQuery,
+    InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery, InternUnionQuery,
+    ItemTreeQuery, LangItemQuery, ModuleLangItemsQuery, StaticDataQuery, StructDataQuery,
+    TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternEagerExpansionQuery, InternMacroQuery,

crates/hir/src/lib.rs

@@ -44,10 +44,9 @@ pub use crate::{
 
 pub use hir_def::{
     adt::StructKind,
-    attr::Attrs,
+    attr::{Attrs, Documentation},
     body::scope::ExprScopes,
     builtin_type::BuiltinType,
-    docs::Documentation,
     find_path::PrefixKind,
     import_map,
     item_scope::ItemInNs,

crates/hir_def/src/attr.rs

@@ -5,10 +5,11 @@ use std::{ops, sync::Arc};
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{hygiene::Hygiene, AstId, InFile};
+use itertools::Itertools;
 use mbe::ast_to_token_tree;
 use syntax::{
     ast::{self, AstNode, AttrsOwner},
-    SmolStr,
+    AstToken, SmolStr,
 };
 use tt::Subtree;
 
@@ -21,6 +22,22 @@ use crate::{
     AdtId, AttrDefId, Lookup,
 };
 
+/// Holds documentation
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Documentation(String);
+
+impl Documentation {
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl Into<String> for Documentation {
+    fn into(self) -> String {
+        self.0
+    }
+}
+
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct Attrs {
     entries: Option<Arc<[Attr]>>,
@@ -93,18 +110,25 @@ impl Attrs {
     }
 
     pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
-        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).doc_comment_text().map(
-            |docs_text| Attr {
-                input: Some(AttrInput::Literal(SmolStr::new(docs_text))),
-                path: ModPath::from(hir_expand::name!(doc)),
-            },
-        );
-        let mut attrs = owner.attrs().peekable();
-        let entries = if attrs.peek().is_none() {
+        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).map(|docs_text| {
+            (
+                docs_text.syntax().text_range().start(),
+                docs_text.doc_comment().map(|doc| Attr {
+                    input: Some(AttrInput::Literal(SmolStr::new(doc))),
+                    path: ModPath::from(hir_expand::name!(doc)),
+                }),
+            )
+        });
+        let attrs = owner
+            .attrs()
+            .map(|attr| (attr.syntax().text_range().start(), Attr::from_src(attr, hygiene)));
+        // sort here by syntax node offset because the source can have doc attributes and doc strings be interleaved
+        let attrs: Vec<_> = docs.chain(attrs).sorted_by_key(|&(offset, _)| offset).collect();
+        let entries = if attrs.is_empty() {
             // Avoid heap allocation
             None
         } else {
-            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).chain(docs).collect())
+            Some(attrs.into_iter().flat_map(|(_, attr)| attr).collect())
         };
         Attrs { entries }
     }
@@ -140,6 +164,24 @@ impl Attrs {
             Some(cfg) => cfg_options.check(&cfg) != Some(false),
         }
     }
+
+    pub fn docs(&self) -> Option<Documentation> {
+        let docs = self
+            .by_key("doc")
+            .attrs()
+            .flat_map(|attr| match attr.input.as_ref()? {
+                AttrInput::Literal(s) => Some(s),
+                AttrInput::TokenTree(_) => None,
+            })
+            .intersperse(&SmolStr::new_inline("\n"))
+            .map(|it| it.as_str())
+            .collect::<String>();
+        if docs.is_empty() {
+            None
+        } else {
+            Some(Documentation(docs.into()))
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -160,8 +202,10 @@ impl Attr {
     fn from_src(ast: ast::Attr, hygiene: &Hygiene) -> Option<Attr> {
         let path = ModPath::from_src(ast.path()?, hygiene)?;
         let input = if let Some(lit) = ast.literal() {
-            // FIXME: escape? raw string?
-            let value = lit.syntax().first_token()?.text().trim_matches('"').into();
+            let value = match lit.kind() {
+                ast::LiteralKind::String(string) => string.value()?.into(),
+                _ => lit.syntax().first_token()?.text().trim_matches('"').into(),
+            };
             Some(AttrInput::Literal(value))
         } else if let Some(tt) = ast.token_tree() {
             Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))

crates/hir_def/src/db.rs

@@ -10,7 +10,6 @@ use crate::{
     attr::Attrs,
     body::{scope::ExprScopes, Body, BodySourceMap},
     data::{ConstData, FunctionData, ImplData, StaticData, TraitData, TypeAliasData},
-    docs::Documentation,
     generics::GenericParams,
     import_map::ImportMap,
     item_tree::ItemTree,
@@ -105,11 +104,6 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
     #[salsa::invoke(LangItems::lang_item_query)]
     fn lang_item(&self, start_crate: CrateId, item: SmolStr) -> Option<LangItemTarget>;
 
-    // FIXME(https://github.com/rust-analyzer/rust-analyzer/issues/2148#issuecomment-550519102)
-    // Remove this query completely, in favor of `Attrs::docs` method
-    #[salsa::invoke(Documentation::documentation_query)]
-    fn documentation(&self, def: AttrDefId) -> Option<Documentation>;
-
     #[salsa::invoke(ImportMap::import_map_query)]
     fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 }

crates/hir_def/src/docs.rs

@@ -31,7 +31,6 @@ pub mod adt;
 pub mod data;
 pub mod generics;
 pub mod lang_item;
-pub mod docs;
 
 pub mod expr;
 pub mod body;

crates/hir_def/src/lib.rs

@@ -372,7 +372,7 @@ fn module_resolution_explicit_path_mod_rs_with_win_separator() {
     check(
         r#"
 //- /main.rs
-#[path = "module\bar\mod.rs"]
+#[path = r"module\bar\mod.rs"]
 mod foo;
 
 //- /module/bar/mod.rs