11 files changed, 282 insertions, 170 deletions

diff --git a/crates/cfg/src/lib.rs b/crates/cfg/src/lib.rs
index 03b8dd767..916d39a0b 100644
--- a/crates/cfg/src/lib.rs
+++ b/crates/cfg/src/lib.rs
@@ -1,4 +1,4 @@
-//! cfg defines conditional compiling options, `cfg` attibute parser and evaluator
+//! cfg defines conditional compiling options, `cfg` attribute parser and evaluator
 
 mod cfg_expr;
 mod dnf;
@@ -52,6 +52,7 @@ impl CfgOptions {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CfgDiff {
     // Invariants: No duplicates, no atom that's both in `enable` and `disable`.
     enable: Vec<CfgAtom>,
@@ -59,6 +60,20 @@ pub struct CfgDiff {
 }
 
 impl CfgDiff {
+    /// Create a new CfgDiff. Will return None if the same item appears more than once in the set
+    /// of both.
+    pub fn new(enable: Vec<CfgAtom>, disable: Vec<CfgAtom>) -> Option<CfgDiff> {
+        let mut occupied = FxHashSet::default();
+        for item in enable.iter().chain(disable.iter()) {
+            if !occupied.insert(item) {
+                // was present
+                return None;
+            }
+        }
+
+        Some(CfgDiff { enable, disable })
+    }
+
     /// Returns the total number of atoms changed by this diff.
     pub fn len(&self) -> usize {
         self.enable.len() + self.disable.len()
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 2e1359eef..0c1da8774 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,8 +1,5 @@
 use either::Either;
-use hir::{
-    AsAssocItem, AssocItemContainer, GenericParam, HasAttrs, HasSource, HirDisplay, InFile, Module,
-    ModuleDef, Semantics,
-};
+use hir::{AsAssocItem, HasAttrs, HasSource, HirDisplay};
 use ide_db::{
     base_db::SourceDatabase,
     defs::{Definition, NameClass, NameRefClass},
@@ -40,6 +37,7 @@ pub struct HoverConfig {
     pub goto_type_def: bool,
     pub links_in_hover: bool,
     pub markdown: bool,
+    pub documentation: bool,
 }
 
 impl HoverConfig {
@@ -51,14 +49,15 @@ impl HoverConfig {
         goto_type_def: false,
         links_in_hover: true,
         markdown: true,
+        documentation: true,
     };
 
-    pub fn any(&self) -> bool {
+    pub fn any_actions(&self) -> bool {
         self.implementations || self.references || self.runnable() || self.goto_type_def
     }
 
-    pub fn none(&self) -> bool {
-        !self.any()
+    pub fn no_actions(&self) -> bool {
+        !self.any_actions()
     }
 
     pub fn runnable(&self) -> bool {
@@ -97,9 +96,10 @@ pub(crate) fn hover(
     db: &RootDatabase,
     position: FilePosition,
     links_in_hover: bool,
+    documentation: bool,
     markdown: bool,
 ) -> Option<RangeInfo<HoverResult>> {
-    let sema = Semantics::new(db);
+    let sema = hir::Semantics::new(db);
     let file = sema.parse(position.file_id).syntax().clone();
     let token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(token);
@@ -131,7 +131,7 @@ pub(crate) fn hover(
                     let (docs, doc_mapping) = attributes.docs_with_rangemap(db)?;
                     let (idl_range, link, ns) =
                         extract_definitions_from_markdown(docs.as_str()).into_iter().find_map(|(range, link, ns)| {
-                            let InFile { file_id, value: range } = doc_mapping.map(range)?;
+                            let hir::InFile { file_id, value: range } = doc_mapping.map(range)?;
                             if file_id == position.file_id.into() && range.contains(position.offset) {
                                 Some((range, link, ns))
                             } else {
@@ -151,12 +151,14 @@ pub(crate) fn hover(
 
     if let Some(definition) = definition {
         let famous_defs = match &definition {
-            Definition::ModuleDef(ModuleDef::BuiltinType(_)) => {
+            Definition::ModuleDef(hir::ModuleDef::BuiltinType(_)) => {
                 Some(FamousDefs(&sema, sema.scope(&node).krate()))
             }
             _ => None,
         };
-        if let Some(markup) = hover_for_definition(db, definition, famous_defs.as_ref()) {
+        if let Some(markup) =
+            hover_for_definition(db, definition, famous_defs.as_ref(), documentation)
+        {
             res.markup = process_markup(sema.db, definition, &markup, links_in_hover, markdown);
             if let Some(action) = show_implementations_action(db, definition) {
                 res.actions.push(action);
@@ -179,7 +181,8 @@ pub(crate) fn hover(
         }
     }
 
-    if let res @ Some(_) = hover_for_keyword(&sema, links_in_hover, markdown, &token) {
+    if let res @ Some(_) = hover_for_keyword(&sema, links_in_hover, markdown, documentation, &token)
+    {
         return res;
     }
 
@@ -261,8 +264,10 @@ fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<Hov
     }
 
     let adt = match def {
-        Definition::ModuleDef(ModuleDef::Trait(it)) => return it.try_to_nav(db).map(to_action),
-        Definition::ModuleDef(ModuleDef::Adt(it)) => Some(it),
+        Definition::ModuleDef(hir::ModuleDef::Trait(it)) => {
+            return it.try_to_nav(db).map(to_action)
+        }
+        Definition::ModuleDef(hir::ModuleDef::Adt(it)) => Some(it),
         Definition::SelfType(it) => it.self_ty(db).as_adt(),
         _ => None,
     }?;
@@ -271,25 +276,27 @@ fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<Hov
 
 fn show_fn_references_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
     match def {
-        Definition::ModuleDef(ModuleDef::Function(it)) => it.try_to_nav(db).map(|nav_target| {
-            HoverAction::Reference(FilePosition {
-                file_id: nav_target.file_id,
-                offset: nav_target.focus_or_full_range().start(),
+        Definition::ModuleDef(hir::ModuleDef::Function(it)) => {
+            it.try_to_nav(db).map(|nav_target| {
+                HoverAction::Reference(FilePosition {
+                    file_id: nav_target.file_id,
+                    offset: nav_target.focus_or_full_range().start(),
+                })
             })
-        }),
+        }
         _ => None,
     }
 }
 
 fn runnable_action(
-    sema: &Semantics<RootDatabase>,
+    sema: &hir::Semantics<RootDatabase>,
     def: Definition,
     file_id: FileId,
 ) -> Option<HoverAction> {
     match def {
         Definition::ModuleDef(it) => match it {
-            ModuleDef::Module(it) => runnable_mod(sema, it).map(HoverAction::Runnable),
-            ModuleDef::Function(func) => {
+            hir::ModuleDef::Module(it) => runnable_mod(sema, it).map(HoverAction::Runnable),
+            hir::ModuleDef::Function(func) => {
                 let src = func.source(sema.db)?;
                 if src.file_id != file_id.into() {
                     cov_mark::hit!(hover_macro_generated_struct_fn_doc_comment);
@@ -306,19 +313,19 @@ fn runnable_action(
 }
 
 fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
-    let mut targets: Vec<ModuleDef> = Vec::new();
-    let mut push_new_def = |item: ModuleDef| {
+    let mut targets: Vec<hir::ModuleDef> = Vec::new();
+    let mut push_new_def = |item: hir::ModuleDef| {
         if !targets.contains(&item) {
             targets.push(item);
         }
     };
 
-    if let Definition::GenericParam(GenericParam::TypeParam(it)) = def {
+    if let Definition::GenericParam(hir::GenericParam::TypeParam(it)) = def {
         it.trait_bounds(db).into_iter().for_each(|it| push_new_def(it.into()));
     } else {
         let ty = match def {
             Definition::Local(it) => it.ty(db),
-            Definition::GenericParam(GenericParam::ConstParam(it)) => it.ty(db),
+            Definition::GenericParam(hir::GenericParam::ConstParam(it)) => it.ty(db),
             _ => return None,
         };
 
@@ -348,29 +355,20 @@ fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
     Some(HoverAction::GoToType(targets))
 }
 
-fn hover_markup(
-    docs: Option<String>,
-    desc: Option<String>,
-    mod_path: Option<String>,
-) -> Option<Markup> {
-    match desc {
-        Some(desc) => {
-            let mut buf = String::new();
-
-            if let Some(mod_path) = mod_path {
-                if !mod_path.is_empty() {
-                    format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
-                }
-            }
-            format_to!(buf, "```rust\n{}\n```", desc);
+fn hover_markup(docs: Option<String>, desc: String, mod_path: Option<String>) -> Option<Markup> {
+    let mut buf = String::new();
 
-            if let Some(doc) = docs {
-                format_to!(buf, "\n___\n\n{}", doc);
-            }
-            Some(buf.into())
+    if let Some(mod_path) = mod_path {
+        if !mod_path.is_empty() {
+            format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
         }
-        None => docs.map(Markup::from),
     }
+    format_to!(buf, "```rust\n{}\n```", desc);
+
+    if let Some(doc) = docs {
+        format_to!(buf, "\n___\n\n{}", doc);
+    }
+    Some(buf.into())
 }
 
 fn process_markup(
@@ -396,11 +394,11 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
         Definition::Field(f) => Some(f.parent_def(db).name(db)),
         Definition::Local(l) => l.parent(db).name(db),
         Definition::ModuleDef(md) => match md {
-            ModuleDef::Function(f) => match f.as_assoc_item(db)?.container(db) {
-                AssocItemContainer::Trait(t) => Some(t.name(db)),
-                AssocItemContainer::Impl(i) => i.self_ty(db).as_adt().map(|adt| adt.name(db)),
+            hir::ModuleDef::Function(f) => match f.as_assoc_item(db)?.container(db) {
+                hir::AssocItemContainer::Trait(t) => Some(t.name(db)),
+                hir::AssocItemContainer::Impl(i) => i.self_ty(db).as_adt().map(|adt| adt.name(db)),
             },
-            ModuleDef::Variant(e) => Some(e.parent_enum(db).name(db)),
+            hir::ModuleDef::Variant(e) => Some(e.parent_enum(db).name(db)),
             _ => None,
         },
         _ => None,
@@ -408,7 +406,7 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
     .map(|name| name.to_string())
 }
 
-fn render_path(db: &RootDatabase, module: Module, item_name: Option<String>) -> String {
+fn render_path(db: &RootDatabase, module: hir::Module, item_name: Option<String>) -> String {
     let crate_name =
         db.crate_graph()[module.krate().into()].display_name.as_ref().map(|it| it.to_string());
     let module_path = module
@@ -420,6 +418,9 @@ fn render_path(db: &RootDatabase, module: Module, item_name: Option<String>) ->
 }
 
 fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
+    if let Definition::GenericParam(_) = def {
+        return None;
+    }
     def.module(db).map(|module| render_path(db, module, definition_owner_name(db, def)))
 }
 
@@ -427,60 +428,53 @@ fn hover_for_definition(
     db: &RootDatabase,
     def: Definition,
     famous_defs: Option<&FamousDefs>,
+    documentation: bool,
 ) -> Option<Markup> {
     let mod_path = definition_mod_path(db, &def);
-    return match def {
+    let (label, docs) = match def {
         Definition::Macro(it) => match &it.source(db)?.value {
             Either::Left(mac) => {
                 let label = macro_label(mac);
-                from_def_source_labeled(db, it, Some(label), mod_path)
+                (label, it.attrs(db).docs())
             }
             Either::Right(_) => {
                 // FIXME
-                None
+                return None;
             }
         },
-        Definition::Field(def) => from_hir_fmt(db, def, mod_path),
+        Definition::Field(def) => label_and_docs(db, def),
         Definition::ModuleDef(it) => match it {
-            ModuleDef::Module(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Function(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Adt(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Variant(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Const(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Static(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Trait(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::TypeAlias(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::BuiltinType(it) => famous_defs
-                .and_then(|fd| hover_for_builtin(fd, it))
-                .or_else(|| Some(Markup::fenced_block(&it.name()))),
+            hir::ModuleDef::Module(it) => label_and_docs(db, it),
+            hir::ModuleDef::Function(it) => label_and_docs(db, it),
+            hir::ModuleDef::Adt(it) => label_and_docs(db, it),
+            hir::ModuleDef::Variant(it) => label_and_docs(db, it),
+            hir::ModuleDef::Const(it) => label_and_docs(db, it),
+            hir::ModuleDef::Static(it) => label_and_docs(db, it),
+            hir::ModuleDef::Trait(it) => label_and_docs(db, it),
+            hir::ModuleDef::TypeAlias(it) => label_and_docs(db, it),
+            hir::ModuleDef::BuiltinType(it) => {
+                return famous_defs
+                    .and_then(|fd| hover_for_builtin(fd, it))
+                    .or_else(|| Some(Markup::fenced_block(&it.name())))
+            }
         },
-        Definition::Local(it) => hover_for_local(it, db),
+        Definition::Local(it) => return hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
-            impl_def.self_ty(db).as_adt().and_then(|adt| from_hir_fmt(db, adt, mod_path))
+            impl_def.self_ty(db).as_adt().map(|adt| label_and_docs(db, adt))?
         }
-        Definition::GenericParam(it) => from_hir_fmt(db, it, None),
-        Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
+        Definition::GenericParam(it) => label_and_docs(db, it),
+        Definition::Label(it) => return Some(Markup::fenced_block(&it.name(db))),
     };
 
-    fn from_hir_fmt<D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
+    return hover_markup(docs.filter(|_| documentation).map(Into::into), label, mod_path);
+
+    fn label_and_docs<D>(db: &RootDatabase, def: D) -> (String, Option<hir::Documentation>)
     where
         D: HasAttrs + HirDisplay,
     {
         let label = def.display(db).to_string();
-        from_def_source_labeled(db, def, Some(label), mod_path)
-    }
-
-    fn from_def_source_labeled<D>(
-        db: &RootDatabase,
-        def: D,
-        short_label: Option<String>,
-        mod_path: Option<String>,
-    ) -> Option<Markup>
-    where
-        D: HasAttrs,
-    {
-        let docs = def.attrs(db).docs().map(Into::into);
-        hover_markup(docs, short_label, mod_path)
+        let docs = def.attrs(db).docs();
+        (label, docs)
     }
 }
 
@@ -504,16 +498,17 @@ fn hover_for_local(it: hir::Local, db: &RootDatabase) -> Option<Markup> {
         }
         Either::Right(_) => format!("{}self: {}", is_mut, ty),
     };
-    hover_markup(None, Some(desc), None)
+    hover_markup(None, desc, None)
 }
 
 fn hover_for_keyword(
-    sema: &Semantics<RootDatabase>,
+    sema: &hir::Semantics<RootDatabase>,
     links_in_hover: bool,
     markdown: bool,
+    documentation: bool,
     token: &SyntaxToken,
 ) -> Option<RangeInfo<HoverResult>> {
-    if !token.kind().is_keyword() {
+    if !token.kind().is_keyword() || !documentation {
         return None;
     }
     let famous_defs = FamousDefs(sema, sema.scope(&token.parent()?).krate());
@@ -524,7 +519,7 @@ fn hover_for_keyword(
     let markup = process_markup(
         sema.db,
         Definition::ModuleDef(doc_owner.into()),
-        &hover_markup(Some(docs.into()), Some(token.text().into()), None)?,
+        &hover_markup(Some(docs.into()), token.text().into(), None)?,
         links_in_hover,
         markdown,
     );
@@ -536,7 +531,7 @@ fn hover_for_builtin(famous_defs: &FamousDefs, builtin: hir::BuiltinType) -> Opt
     let primitive_mod = format!("prim_{}", builtin.name());
     let doc_owner = find_std_module(famous_defs, &primitive_mod)?;
     let docs = doc_owner.attrs(famous_defs.0.db).docs()?;
-    hover_markup(Some(docs.into()), Some(builtin.name().to_string()), None)
+    hover_markup(Some(docs.into()), builtin.name().to_string(), None)
 }
 
 fn find_std_module(famous_defs: &FamousDefs, name: &str) -> Option<hir::Module> {
@@ -570,12 +565,12 @@ mod tests {
 
     fn check_hover_no_result(ra_fixture: &str) {
         let (analysis, position) = fixture::position(ra_fixture);
-        assert!(analysis.hover(position, true, true).unwrap().is_none());
+        assert!(analysis.hover(position, true, true, true).unwrap().is_none());
     }
 
     fn check(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, true, true).unwrap().unwrap();
+        let hover = analysis.hover(position, true, true, true).unwrap().unwrap();
 
         let content = analysis.db.file_text(position.file_id);
         let hovered_element = &content[hover.range];
@@ -586,7 +581,7 @@ mod tests {
 
     fn check_hover_no_links(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, false, true).unwrap().unwrap();
+        let hover = analysis.hover(position, false, true, true).unwrap().unwrap();
 
         let content = analysis.db.file_text(position.file_id);
         let hovered_element = &content[hover.range];
@@ -597,7 +592,7 @@ mod tests {
 
     fn check_hover_no_markdown(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, true, false).unwrap().unwrap();
+        let hover = analysis.hover(position, true, true, false).unwrap().unwrap();
 
         let content = analysis.db.file_text(position.file_id);
         let hovered_element = &content[hover.range];
@@ -608,7 +603,7 @@ mod tests {
 
     fn check_actions(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, true, true).unwrap().unwrap();
+        let hover = analysis.hover(position, true, true, true).unwrap().unwrap();
         expect.assert_debug_eq(&hover.info.actions)
     }
 
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 4bd073cc3..3798f32cc 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -408,9 +408,10 @@ impl Analysis {
         &self,
         position: FilePosition,
         links_in_hover: bool,
+        documentation: bool,
         markdown: bool,
     ) -> Cancellable<Option<RangeInfo<HoverResult>>> {
-        self.with_db(|db| hover::hover(db, position, links_in_hover, markdown))
+        self.with_db(|db| hover::hover(db, position, links_in_hover, documentation, markdown))
     }
 
     /// Return URL(s) for the documentation of the symbol under the cursor.
diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index ac7f0959b..870d4f665 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -109,10 +109,15 @@ pub(crate) fn extract_function(acc: &mut Assists, ctx: &AssistContext) -> Option
 
             let new_indent = IndentLevel::from_node(&insert_after);
             let old_indent = fun.body.indent_level();
+            let body_contains_await = body_contains_await(&fun.body);
 
-            builder.replace(target_range, format_replacement(ctx, &fun, old_indent));
+            builder.replace(
+                target_range,
+                format_replacement(ctx, &fun, old_indent, body_contains_await),
+            );
 
-            let fn_def = format_function(ctx, module, &fun, old_indent, new_indent);
+            let fn_def =
+                format_function(ctx, module, &fun, old_indent, new_indent, body_contains_await);
             let insert_offset = insert_after.text_range().end();
             match ctx.config.snippet_cap {
                 Some(cap) => builder.insert_snippet(cap, insert_offset, fn_def),
@@ -954,7 +959,12 @@ fn scope_for_fn_insertion_node(node: &SyntaxNode, anchor: Anchor) -> Option<Synt
     last_ancestor
 }
 
-fn format_replacement(ctx: &AssistContext, fun: &Function, indent: IndentLevel) -> String {
+fn format_replacement(
+    ctx: &AssistContext,
+    fun: &Function,
+    indent: IndentLevel,
+    body_contains_await: bool,
+) -> String {
     let ret_ty = fun.return_type(ctx);
 
     let args = fun.params.iter().map(|param| param.to_arg(ctx));
@@ -994,6 +1004,9 @@ fn format_replacement(ctx: &AssistContext, fun: &Function, indent: IndentLevel)
         }
     }
     format_to!(buf, "{}", expr);
+    if body_contains_await {
+        buf.push_str(".await");
+    }
     if fun.ret_ty.is_unit()
         && (!fun.vars_defined_in_body_and_outlive.is_empty() || !expr.is_block_like())
     {
@@ -1122,12 +1135,13 @@ fn format_function(
     fun: &Function,
     old_indent: IndentLevel,
     new_indent: IndentLevel,
+    body_contains_await: bool,
 ) -> String {
     let mut fn_def = String::new();
     let params = make_param_list(ctx, module, fun);
     let ret_ty = make_ret_ty(ctx, module, fun);
     let body = make_body(ctx, old_indent, new_indent, fun);
-    let async_kw = if body_contains_await(&fun.body) { "async " } else { "" };
+    let async_kw = if body_contains_await { "async " } else { "" };
     match ctx.config.snippet_cap {
         Some(_) => format_to!(fn_def, "\n\n{}{}fn $0{}{}", new_indent, async_kw, fun.name, params),
         None => format_to!(fn_def, "\n\n{}{}fn {}{}", new_indent, async_kw, fun.name, params),
@@ -3681,7 +3695,7 @@ async fn some_function() {
 "#,
             r#"
 fn main() {
-    fun_name();
+    fun_name().await;
 }
 
 async fn $0fun_name() {
@@ -3710,7 +3724,7 @@ async fn some_function() {
 "#,
             r#"
 fn main() {
-    fun_name();
+    fun_name().await;
 }
 
 async fn $0fun_name() {
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index ac079f83e..0935ea967 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -1,5 +1,6 @@
 //! See [`CargoWorkspace`].
 
+use std::iter;
 use std::path::PathBuf;
 use std::{convert::TryInto, ops, process::Command, sync::Arc};
 
@@ -12,6 +13,7 @@ use rustc_hash::FxHashMap;
 use serde::Deserialize;
 use serde_json::from_value;
 
+use crate::CfgOverrides;
 use crate::{build_data::BuildDataConfig, utf8_stdout};
 
 /// [`CargoWorkspace`] represents the logical structure of, well, a Cargo
@@ -76,6 +78,21 @@ pub struct CargoConfig {
 
     /// rustc private crate source
     pub rustc_source: Option<RustcSource>,
+
+    /// crates to disable `#[cfg(test)]` on
+    pub unset_test_crates: Vec<String>,
+}
+
+impl CargoConfig {
+    pub fn cfg_overrides(&self) -> CfgOverrides {
+        self.unset_test_crates
+            .iter()
+            .cloned()
+            .zip(iter::repeat_with(|| {
+                cfg::CfgDiff::new(Vec::new(), vec![cfg::CfgAtom::Flag("test".into())]).unwrap()
+            }))
+            .collect()
+    }
 }
 
 pub type Package = Idx<PackageData>;
diff --git a/crates/project_model/src/lib.rs b/crates/project_model/src/lib.rs
index 8c6cf94c2..1d408dff2 100644
--- a/crates/project_model/src/lib.rs
+++ b/crates/project_model/src/lib.rs
@@ -41,7 +41,7 @@ pub use crate::{
     },
     project_json::{ProjectJson, ProjectJsonData},
     sysroot::Sysroot,
-    workspace::{PackageRoot, ProjectWorkspace},
+    workspace::{CfgOverrides, PackageRoot, ProjectWorkspace},
 };
 
 pub use proc_macro_api::ProcMacroClient;
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index ef0f3c9e4..d8217f714 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -7,7 +7,7 @@ use std::{collections::VecDeque, fmt, fs, path::Path, process::Command};
 use anyhow::{format_err, Context, Result};
 use base_db::{CrateDisplayName, CrateGraph, CrateId, CrateName, Edition, Env, FileId, ProcMacro};
 use cargo_workspace::DepKind;
-use cfg::CfgOptions;
+use cfg::{CfgDiff, CfgOptions};
 use paths::{AbsPath, AbsPathBuf};
 use proc_macro_api::ProcMacroClient;
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -22,6 +22,8 @@ use crate::{
     Sysroot, TargetKind,
 };
 
+pub type CfgOverrides = FxHashMap<String, CfgDiff>;
+
 /// `PackageRoot` describes a package root folder.
 /// Which may be an external dependency, or a member of
 /// the current workspace.
@@ -46,6 +48,7 @@ pub enum ProjectWorkspace {
         /// FIXME: make this a per-crate map, as, eg, build.rs might have a
         /// different target.
         rustc_cfg: Vec<CfgFlag>,
+        cfg_overrides: CfgOverrides,
     },
     /// Project workspace was manually specified using a `rust-project.json` file.
     Json { project: ProjectJson, sysroot: Option<Sysroot>, rustc_cfg: Vec<CfgFlag> },
@@ -67,7 +70,7 @@ impl fmt::Debug for ProjectWorkspace {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // Make sure this isn't too verbose.
         match self {
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg } => f
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg, cfg_overrides } => f
                 .debug_struct("Cargo")
                 .field("root", &cargo.workspace_root().file_name())
                 .field("n_packages", &cargo.packages().len())
@@ -77,6 +80,7 @@ impl fmt::Debug for ProjectWorkspace {
                     &rustc.as_ref().map_or(0, |rc| rc.packages().len()),
                 )
                 .field("n_rustc_cfg", &rustc_cfg.len())
+                .field("n_cfg_overrides", &cfg_overrides.len())
                 .finish(),
             ProjectWorkspace::Json { project, sysroot, rustc_cfg } => {
                 let mut debug_struct = f.debug_struct("Json");
@@ -164,7 +168,9 @@ impl ProjectWorkspace {
                 };
 
                 let rustc_cfg = rustc_cfg::get(Some(&cargo_toml), config.target.as_deref());
-                ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg }
+
+                let cfg_overrides = config.cfg_overrides();
+                ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg, cfg_overrides }
             }
         };
 
@@ -213,43 +219,45 @@ impl ProjectWorkspace {
                     })
                 }))
                 .collect::<Vec<_>>(),
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg: _ } => cargo
-                .packages()
-                .map(|pkg| {
-                    let is_member = cargo[pkg].is_member;
-                    let pkg_root = cargo[pkg].root().to_path_buf();
-
-                    let mut include = vec![pkg_root.clone()];
-                    include.extend(
-                        build_data
-                            .and_then(|it| it.get(cargo.workspace_root()))
-                            .and_then(|map| map.get(&cargo[pkg].id))
-                            .and_then(|it| it.out_dir.clone()),
-                    );
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg: _, cfg_overrides: _ } => {
+                cargo
+                    .packages()
+                    .map(|pkg| {
+                        let is_member = cargo[pkg].is_member;
+                        let pkg_root = cargo[pkg].root().to_path_buf();
+
+                        let mut include = vec![pkg_root.clone()];
+                        include.extend(
+                            build_data
+                                .and_then(|it| it.get(cargo.workspace_root()))
+                                .and_then(|map| map.get(&cargo[pkg].id))
+                                .and_then(|it| it.out_dir.clone()),
+                        );
 
-                    let mut exclude = vec![pkg_root.join(".git")];
-                    if is_member {
-                        exclude.push(pkg_root.join("target"));
-                    } else {
-                        exclude.push(pkg_root.join("tests"));
-                        exclude.push(pkg_root.join("examples"));
-                        exclude.push(pkg_root.join("benches"));
-                    }
-                    PackageRoot { is_member, include, exclude }
-                })
-                .chain(sysroot.crates().map(|krate| PackageRoot {
-                    is_member: false,
-                    include: vec![sysroot[krate].root_dir().to_path_buf()],
-                    exclude: Vec::new(),
-                }))
-                .chain(rustc.into_iter().flat_map(|rustc| {
-                    rustc.packages().map(move |krate| PackageRoot {
+                        let mut exclude = vec![pkg_root.join(".git")];
+                        if is_member {
+                            exclude.push(pkg_root.join("target"));
+                        } else {
+                            exclude.push(pkg_root.join("tests"));
+                            exclude.push(pkg_root.join("examples"));
+                            exclude.push(pkg_root.join("benches"));
+                        }
+                        PackageRoot { is_member, include, exclude }
+                    })
+                    .chain(sysroot.crates().map(|krate| PackageRoot {
                         is_member: false,
-                        include: vec![rustc[krate].root().to_path_buf()],
+                        include: vec![sysroot[krate].root_dir().to_path_buf()],
                         exclude: Vec::new(),
-                    })
-                }))
-                .collect(),
+                    }))
+                    .chain(rustc.into_iter().flat_map(|rustc| {
+                        rustc.packages().map(move |krate| PackageRoot {
+                            is_member: false,
+                            include: vec![rustc[krate].root().to_path_buf()],
+                            exclude: Vec::new(),
+                        })
+                    }))
+                    .collect()
+            }
             ProjectWorkspace::DetachedFiles { files, sysroot, .. } => files
                 .into_iter()
                 .map(|detached_file| PackageRoot {
@@ -299,16 +307,22 @@ impl ProjectWorkspace {
                 project,
                 sysroot,
             ),
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg } => cargo_to_crate_graph(
-                rustc_cfg.clone(),
-                &proc_macro_loader,
-                load,
-                cargo,
-                build_data.and_then(|it| it.get(cargo.workspace_root())),
-                sysroot,
-                rustc,
-                rustc.as_ref().zip(build_data).and_then(|(it, map)| map.get(it.workspace_root())),
-            ),
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg, cfg_overrides } => {
+                cargo_to_crate_graph(
+                    rustc_cfg.clone(),
+                    cfg_overrides,
+                    &proc_macro_loader,
+                    load,
+                    cargo,
+                    build_data.and_then(|it| it.get(cargo.workspace_root())),
+                    sysroot,
+                    rustc,
+                    rustc
+                        .as_ref()
+                        .zip(build_data)
+                        .and_then(|(it, map)| map.get(it.workspace_root())),
+                )
+            }
             ProjectWorkspace::DetachedFiles { files, sysroot, rustc_cfg } => {
                 detached_files_to_crate_graph(rustc_cfg.clone(), load, files, sysroot)
             }
@@ -398,6 +412,7 @@ fn project_json_to_crate_graph(
 
 fn cargo_to_crate_graph(
     rustc_cfg: Vec<CfgFlag>,
+    override_cfg: &CfgOverrides,
     proc_macro_loader: &dyn Fn(&Path) -> Vec<ProcMacro>,
     load: &mut dyn FnMut(&AbsPath) -> Option<FileId>,
     cargo: &CargoWorkspace,
@@ -425,6 +440,21 @@ fn cargo_to_crate_graph(
     let mut has_private = false;
     // Next, create crates for each package, target pair
     for pkg in cargo.packages() {
+        let mut cfg_options = &cfg_options;
+        let mut replaced_cfg_options;
+        if let Some(overrides) = override_cfg.get(&cargo[pkg].name) {
+            // FIXME: this is sort of a hack to deal with #![cfg(not(test))] vanishing such as seen
+            // in ed25519_dalek (#7243), and libcore (#9203) (although you only hit that one while
+            // working on rust-lang/rust as that's the only time it appears outside sysroot).
+            //
+            // A more ideal solution might be to reanalyze crates based on where the cursor is and
+            // figure out the set of cfgs that would have to apply to make it active.
+
+            replaced_cfg_options = cfg_options.clone();
+            replaced_cfg_options.apply_diff(overrides.clone());
+            cfg_options = &replaced_cfg_options;
+        };
+
         has_private |= cargo[pkg].metadata.rustc_private;
         let mut lib_tgt = None;
         for &tgt in cargo[pkg].targets.iter() {
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 16c295639..3aeca8839 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -55,6 +55,8 @@ config_data! {
         cargo_autoreload: bool           = "true",
         /// Activate all available features (`--all-features`).
         cargo_allFeatures: bool          = "false",
+        /// Unsets `#[cfg(test)]` for the specified crates.
+        cargo_unsetTest: Vec<String>   = "[\"core\"]",
         /// List of features to activate.
         cargo_features: Vec<String>      = "[]",
         /// Run build scripts (`build.rs`) for more precise code analysis.
@@ -144,6 +146,12 @@ config_data! {
         /// their contents.
         highlighting_strings: bool = "true",
 
+        /// Whether to show documentation on hover.
+        hover_documentation: bool       = "true",
+        /// Use markdown syntax for links in hover.
+        hover_linksInHover |
+        hoverActions_linksInHover: bool = "true",
+
         /// Whether to show `Debug` action. Only applies when
         /// `#rust-analyzer.hoverActions.enable#` is set.
         hoverActions_debug: bool           = "true",
@@ -161,8 +169,6 @@ config_data! {
         /// Whether to show `Run` action. Only applies when
         /// `#rust-analyzer.hoverActions.enable#` is set.
         hoverActions_run: bool             = "true",
-        /// Use markdown syntax for links in hover.
-        hoverActions_linksInHover: bool    = "true",
 
         /// Whether to show inlay type hints for method chains.
         inlayHints_chainingHints: bool      = "true",
@@ -595,8 +601,10 @@ impl Config {
             target: self.data.cargo_target.clone(),
             rustc_source,
             no_sysroot: self.data.cargo_noSysroot,
+            unset_test_crates: self.data.cargo_unsetTest.clone(),
         }
     }
+
     pub fn rustfmt(&self) -> RustfmtConfig {
         match &self.data.rustfmt_overrideCommand {
             Some(args) if !args.is_empty() => {
@@ -730,7 +738,7 @@ impl Config {
             run: self.data.hoverActions_enable && self.data.hoverActions_run,
             debug: self.data.hoverActions_enable && self.data.hoverActions_debug,
             goto_type_def: self.data.hoverActions_enable && self.data.hoverActions_gotoTypeDef,
-            links_in_hover: self.data.hoverActions_linksInHover,
+            links_in_hover: self.data.hover_linksInHover,
             markdown: try_or!(
                 self.caps
                     .text_document
@@ -743,6 +751,7 @@ impl Config {
                 &[]
             )
             .contains(&MarkupKind::Markdown),
+            documentation: self.data.hover_documentation,
         }
     }
 
@@ -852,6 +861,7 @@ macro_rules! _config_data {
                     $({
                         let field = stringify!($field);
                         let ty = stringify!($ty);
+
                         (field, ty, &[$($doc),*], $default)
                     },)*
                 ])
@@ -863,6 +873,7 @@ macro_rules! _config_data {
                     $({
                         let field = stringify!($field);
                         let ty = stringify!($ty);
+
                         (field, ty, &[$($doc),*], $default)
                     },)*
                 ])
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index ccf66294f..eff1e6c93 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -862,11 +862,15 @@ pub(crate) fn handle_hover(
     let _p = profile::span("handle_hover");
     let position = from_proto::file_position(&snap, params.text_document_position_params)?;
     let hover_config = snap.config.hover();
-    let info =
-        match snap.analysis.hover(position, hover_config.links_in_hover, hover_config.markdown)? {
-            None => return Ok(None),
-            Some(info) => info,
-        };
+    let info = match snap.analysis.hover(
+        position,
+        hover_config.links_in_hover,
+        hover_config.documentation,
+        hover_config.markdown,
+    )? {
+        None => return Ok(None),
+        Some(info) => info,
+    };
     let line_index = snap.file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, info.range);
     let hover = lsp_ext::Hover {
@@ -1587,7 +1591,7 @@ fn prepare_hover_actions(
     snap: &GlobalStateSnapshot,
     actions: &[HoverAction],
 ) -> Vec<lsp_ext::CommandLinkGroup> {
-    if snap.config.hover().none() || !snap.config.hover_actions() {
+    if snap.config.hover().no_actions() || !snap.config.hover_actions() {
         return Vec::new();
     }
 
diff --git a/docs/user/generated_config.adoc b/docs/user/generated_config.adoc
index 18ea77266..cc7fdd38f 100644
--- a/docs/user/generated_config.adoc
+++ b/docs/user/generated_config.adoc
@@ -39,6 +39,11 @@ Automatically refresh project info via `cargo metadata` on
 --
 Activate all available features (`--all-features`).
 --
+[[rust-analyzer.cargo.unsetTest]]rust-analyzer.cargo.unsetTest (default: `["core"]`)::
++
+--
+Unsets `#[cfg(test)]` for the specified crates.
+--
 [[rust-analyzer.cargo.features]]rust-analyzer.cargo.features (default: `[]`)::
 +
 --
@@ -210,6 +215,16 @@ In some editors (e.g. vscode) semantic tokens override other highlighting gramma
 By disabling semantic tokens for strings, other grammars can be used to highlight
 their contents.
 --
+[[rust-analyzer.hover.documentation]]rust-analyzer.hover.documentation (default: `true`)::
++
+--
+Whether to show documentation on hover.
+--
+[[rust-analyzer.hover.linksInHover]]rust-analyzer.hover.linksInHover (default: `true`)::
++
+--
+Use markdown syntax for links in hover.
+--
 [[rust-analyzer.hoverActions.debug]]rust-analyzer.hoverActions.debug (default: `true`)::
 +
 --
@@ -245,11 +260,6 @@ Whether to show `References` action. Only applies when
 Whether to show `Run` action. Only applies when
 `#rust-analyzer.hoverActions.enable#` is set.
 --
-[[rust-analyzer.hoverActions.linksInHover]]rust-analyzer.hoverActions.linksInHover (default: `true`)::
-+
---
-Use markdown syntax for links in hover.
---
 [[rust-analyzer.inlayHints.chainingHints]]rust-analyzer.inlayHints.chainingHints (default: `true`)::
 +
 --
diff --git a/editors/code/package.json b/editors/code/package.json
index c077bd2c0..666016ae4 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -452,6 +452,16 @@
                     "default": false,
                     "type": "boolean"
                 },
+                "rust-analyzer.cargo.unsetTest": {
+                    "markdownDescription": "Unsets `#[cfg(test)]` for the specified crates.",
+                    "default": [
+                        "core"
+                    ],
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
                 "rust-analyzer.cargo.features": {
                     "markdownDescription": "List of features to activate.",
                     "default": [],
@@ -645,6 +655,16 @@
                     "default": true,
                     "type": "boolean"
                 },
+                "rust-analyzer.hover.documentation": {
+                    "markdownDescription": "Whether to show documentation on hover.",
+                    "default": true,
+                    "type": "boolean"
+                },
+                "rust-analyzer.hover.linksInHover": {
+                    "markdownDescription": "Use markdown syntax for links in hover.",
+                    "default": true,
+                    "type": "boolean"
+                },
                 "rust-analyzer.hoverActions.debug": {
                     "markdownDescription": "Whether to show `Debug` action. Only applies when\n`#rust-analyzer.hoverActions.enable#` is set.",
                     "default": true,
@@ -675,11 +695,6 @@
                     "default": true,
                     "type": "boolean"
                 },
-                "rust-analyzer.hoverActions.linksInHover": {
-                    "markdownDescription": "Use markdown syntax for links in hover.",
-                    "default": true,
-                    "type": "boolean"
-                },
                 "rust-analyzer.inlayHints.chainingHints": {
                     "markdownDescription": "Whether to show inlay type hints for method chains.",
                     "default": true,