18 files changed, 379 insertions, 126 deletions

diff --git a/crates/assists/src/handlers/fix_visibility.rs b/crates/assists/src/handlers/fix_visibility.rs
index 7cd76ea06..d505e9444 100644
--- a/crates/assists/src/handlers/fix_visibility.rs
+++ b/crates/assists/src/handlers/fix_visibility.rs
@@ -324,14 +324,14 @@ pub struct Foo { pub bar: () }
 
     #[test]
     fn fix_visibility_of_enum_variant_field() {
-        check_assist(
+        // Enum variants, as well as their fields, always get the enum's visibility. In fact, rustc
+        // rejects any visibility specifiers on them, so this assist should never fire on them.
+        check_assist_not_applicable(
             fix_visibility,
             r"mod foo { pub enum Foo { Bar { bar: () } } }
               fn main() { foo::Foo::Bar { <|>bar: () }; } ",
-            r"mod foo { pub enum Foo { Bar { $0pub(crate) bar: () } } }
-              fn main() { foo::Foo::Bar { bar: () }; } ",
         );
-        check_assist(
+        check_assist_not_applicable(
             fix_visibility,
             r"
 //- /lib.rs
@@ -340,8 +340,6 @@ fn main() { foo::Foo::Bar { <|>bar: () }; }
 //- /foo.rs
 pub enum Foo { Bar { bar: () } }
 ",
-            r"pub enum Foo { Bar { $0pub(crate) bar: () } }
-",
         );
         check_assist_not_applicable(
             fix_visibility,
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 5918b9541..66fc11611 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -189,6 +189,10 @@ impl SourceToDefCtx<'_, '_> {
                         let def = self.type_alias_to_def(container.with_value(it))?;
                         def.into()
                     },
+                    ast::Variant(it) => {
+                        let def = self.enum_variant_to_def(container.with_value(it))?;
+                        VariantId::from(def).into()
+                    },
                     _ => continue,
                 }
             };
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index d69ff2fc7..6539959c3 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -14,7 +14,7 @@ use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
 use crate::{
     body::{CfgExpander, LowerCtx},
     db::DefDatabase,
-    item_tree::{AttrOwner, Field, Fields, ItemTree, ModItem},
+    item_tree::{AttrOwner, Field, Fields, ItemTree, ModItem, RawVisibilityId},
     src::HasChildSource,
     src::HasSource,
     trace::Trace,
@@ -91,7 +91,7 @@ impl StructData {
         let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
 
         let strukt = &item_tree[loc.id.value];
-        let variant_data = lower_fields(&item_tree, &cfg_options, &strukt.fields);
+        let variant_data = lower_fields(&item_tree, &cfg_options, &strukt.fields, None);
         Arc::new(StructData {
             name: strukt.name.clone(),
             variant_data: Arc::new(variant_data),
@@ -105,7 +105,7 @@ impl StructData {
         let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
 
         let union = &item_tree[loc.id.value];
-        let variant_data = lower_fields(&item_tree, &cfg_options, &union.fields);
+        let variant_data = lower_fields(&item_tree, &cfg_options, &union.fields, None);
 
         Arc::new(StructData {
             name: union.name.clone(),
@@ -126,7 +126,8 @@ impl EnumData {
         for var_id in enum_.variants.clone() {
             if item_tree.attrs(var_id.into()).is_cfg_enabled(&cfg_options) {
                 let var = &item_tree[var_id];
-                let var_data = lower_fields(&item_tree, &cfg_options, &var.fields);
+                let var_data =
+                    lower_fields(&item_tree, &cfg_options, &var.fields, Some(enum_.visibility));
 
                 variants.alloc(EnumVariantData {
                     name: var.name.clone(),
@@ -296,13 +297,18 @@ fn lower_struct(
     }
 }
 
-fn lower_fields(item_tree: &ItemTree, cfg_options: &CfgOptions, fields: &Fields) -> VariantData {
+fn lower_fields(
+    item_tree: &ItemTree,
+    cfg_options: &CfgOptions,
+    fields: &Fields,
+    override_visibility: Option<RawVisibilityId>,
+) -> VariantData {
     match fields {
         Fields::Record(flds) => {
             let mut arena = Arena::new();
             for field_id in flds.clone() {
                 if item_tree.attrs(field_id.into()).is_cfg_enabled(cfg_options) {
-                    arena.alloc(lower_field(item_tree, &item_tree[field_id]));
+                    arena.alloc(lower_field(item_tree, &item_tree[field_id], override_visibility));
                 }
             }
             VariantData::Record(arena)
@@ -311,7 +317,7 @@ fn lower_fields(item_tree: &ItemTree, cfg_options: &CfgOptions, fields: &Fields)
             let mut arena = Arena::new();
             for field_id in flds.clone() {
                 if item_tree.attrs(field_id.into()).is_cfg_enabled(cfg_options) {
-                    arena.alloc(lower_field(item_tree, &item_tree[field_id]));
+                    arena.alloc(lower_field(item_tree, &item_tree[field_id], override_visibility));
                 }
             }
             VariantData::Tuple(arena)
@@ -320,10 +326,14 @@ fn lower_fields(item_tree: &ItemTree, cfg_options: &CfgOptions, fields: &Fields)
     }
 }
 
-fn lower_field(item_tree: &ItemTree, field: &Field) -> FieldData {
+fn lower_field(
+    item_tree: &ItemTree,
+    field: &Field,
+    override_visibility: Option<RawVisibilityId>,
+) -> FieldData {
     FieldData {
         name: field.name.clone(),
         type_ref: field.type_ref.clone(),
-        visibility: item_tree[field.visibility].clone(),
+        visibility: item_tree[override_visibility.unwrap_or(field.visibility)].clone(),
     }
 }
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 0f3c85926..e9c62c6aa 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -17,9 +17,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = "0.32"
-chalk-ir = "0.32"
-chalk-recursive = "0.32"
+chalk-solve = "0.33"
+chalk-ir = "0.33"
+chalk-recursive = "0.33"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 hir_def = { path = "../hir_def", version = "0.0.0" }
diff --git a/crates/ide/src/completion/complete_postfix/format_like.rs b/crates/ide/src/completion/complete_postfix/format_like.rs
index 81c33bf3a..50d1e5c81 100644
--- a/crates/ide/src/completion/complete_postfix/format_like.rs
+++ b/crates/ide/src/completion/complete_postfix/format_like.rs
@@ -25,6 +25,7 @@ static KINDS: &[(&str, &str)] = &[
     ("fmt", "format!"),
     ("panic", "panic!"),
     ("println", "println!"),
+    ("eprintln", "eprintln!"),
     ("logd", "log::debug!"),
     ("logt", "log::trace!"),
     ("logi", "log::info!"),
@@ -259,6 +260,7 @@ mod tests {
     fn test_into_suggestion() {
         let test_vector = &[
             ("println!", "{}", r#"println!("{}", $1)"#),
+            ("eprintln!", "{}", r#"eprintln!("{}", $1)"#),
             (
                 "log::info!",
                 "{} {expr} {} {2 + 2}",
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 5db6e1311..686cee3a1 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -77,7 +77,9 @@ pub use crate::{
     hover::{HoverAction, HoverConfig, HoverGotoTypeData, HoverResult},
     inlay_hints::{InlayHint, InlayHintsConfig, InlayKind},
     markup::Markup,
-    references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
+    references::{
+        Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult, RenameError,
+    },
     runnables::{Runnable, RunnableKind, TestId},
     syntax_highlighting::{
         Highlight, HighlightModifier, HighlightModifiers, HighlightTag, HighlightedRange,
@@ -498,7 +500,7 @@ impl Analysis {
         &self,
         position: FilePosition,
         new_name: &str,
-    ) -> Cancelable<Option<RangeInfo<SourceChange>>> {
+    ) -> Cancelable<Result<RangeInfo<SourceChange>, RenameError>> {
         self.with_db(|db| references::rename(db, position, new_name))
     }
 
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index e0830eb4f..f65a05ea3 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -26,6 +26,7 @@ use syntax::{
 use crate::{display::TryToNav, FilePosition, FileRange, NavigationTarget, RangeInfo};
 
 pub(crate) use self::rename::rename;
+pub use self::rename::RenameError;
 
 pub use ide_db::search::{Reference, ReferenceAccess, ReferenceKind};
 
@@ -406,6 +407,23 @@ enum Foo {
     }
 
     #[test]
+    fn test_find_all_refs_enum_var_field() {
+        check(
+            r#"
+enum Foo {
+    A,
+    B { field<|>: u8 },
+    C,
+}
+"#,
+            expect![[r#"
+                field RECORD_FIELD FileId(0) 26..35 26..31 Other
+
+            "#]],
+        );
+    }
+
+    #[test]
     fn test_find_all_refs_two_modules() {
         check(
             r#"
@@ -669,6 +687,76 @@ fn g() { f(); }
         );
     }
 
+    #[test]
+    fn test_find_all_refs_struct_pat() {
+        check(
+            r#"
+struct S {
+    field<|>: u8,
+}
+
+fn f(s: S) {
+    match s {
+        S { field } => {}
+    }
+}
+"#,
+            expect![[r#"
+                field RECORD_FIELD FileId(0) 15..24 15..20 Other
+
+                FileId(0) 68..73 FieldShorthandForField Read
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_enum_var_pat() {
+        check(
+            r#"
+enum En {
+    Variant {
+        field<|>: u8,
+    }
+}
+
+fn f(e: En) {
+    match e {
+        En::Variant { field } => {}
+    }
+}
+"#,
+            expect![[r#"
+                field RECORD_FIELD FileId(0) 32..41 32..37 Other
+
+                FileId(0) 102..107 FieldShorthandForField Read
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_enum_var_privacy() {
+        check(
+            r#"
+mod m {
+    pub enum En {
+        Variant {
+            field<|>: u8,
+        }
+    }
+}
+
+fn f() -> m::En {
+    m::En::Variant { field: 0 }
+}
+"#,
+            expect![[r#"
+                field RECORD_FIELD FileId(0) 56..65 56..61 Other
+
+                FileId(0) 125..130 Other Read
+            "#]],
+        );
+    }
+
     fn check(ra_fixture: &str, expect: Expect) {
         check_with_scope(ra_fixture, None, expect)
     }
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 8cbe1ae5a..f3b5cfc8c 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -6,11 +6,16 @@ use ide_db::{
     defs::{classify_name, classify_name_ref, Definition, NameClass, NameRefClass},
     RootDatabase,
 };
-use std::convert::TryInto;
+
+use std::{
+    convert::TryInto,
+    error::Error,
+    fmt::{self, Display},
+};
 use syntax::{
     algo::find_node_at_offset,
     ast::{self, NameOwner},
-    lex_single_valid_syntax_kind, match_ast, AstNode, SyntaxKind, SyntaxNode, SyntaxToken,
+    lex_single_syntax_kind, match_ast, AstNode, SyntaxKind, SyntaxNode, SyntaxToken,
 };
 use test_utils::mark;
 use text_edit::TextEdit;
@@ -20,17 +25,37 @@ use crate::{
     SourceChange, SourceFileEdit, TextRange, TextSize,
 };
 
+#[derive(Debug)]
+pub struct RenameError(pub(crate) String);
+
+impl fmt::Display for RenameError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        Display::fmt(&self.0, f)
+    }
+}
+
+impl Error for RenameError {}
+
 pub(crate) fn rename(
     db: &RootDatabase,
     position: FilePosition,
     new_name: &str,
-) -> Option<RangeInfo<SourceChange>> {
+) -> Result<RangeInfo<SourceChange>, RenameError> {
     let sema = Semantics::new(db);
 
-    match lex_single_valid_syntax_kind(new_name)? {
-        SyntaxKind::IDENT | SyntaxKind::UNDERSCORE => (),
-        SyntaxKind::SELF_KW => return rename_to_self(&sema, position),
-        _ => return None,
+    match lex_single_syntax_kind(new_name) {
+        Some(res) => match res {
+            (SyntaxKind::IDENT, _) => (),
+            (SyntaxKind::UNDERSCORE, _) => (),
+            (SyntaxKind::SELF_KW, _) => return rename_to_self(&sema, position),
+            (_, Some(syntax_error)) => {
+                return Err(RenameError(format!("Invalid name `{}`: {}", new_name, syntax_error)))
+            }
+            (_, None) => {
+                return Err(RenameError(format!("Invalid name `{}`: not an identifier", new_name)))
+            }
+        },
+        None => return Err(RenameError(format!("Invalid name `{}`: not an identifier", new_name))),
     }
 
     let source_file = sema.parse(position.file_id);
@@ -103,7 +128,7 @@ fn rename_mod(
     position: FilePosition,
     module: Module,
     new_name: &str,
-) -> Option<RangeInfo<SourceChange>> {
+) -> Result<RangeInfo<SourceChange>, RenameError> {
     let mut source_file_edits = Vec::new();
     let mut file_system_edits = Vec::new();
 
@@ -125,7 +150,7 @@ fn rename_mod(
 
     if let Some(src) = module.declaration_source(sema.db) {
         let file_id = src.file_id.original_file(sema.db);
-        let name = src.value.name()?;
+        let name = src.value.name().unwrap();
         let edit = SourceFileEdit {
             file_id,
             edit: TextEdit::replace(name.syntax().text_range(), new_name.into()),
@@ -133,35 +158,40 @@ fn rename_mod(
         source_file_edits.push(edit);
     }
 
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)
+        .ok_or_else(|| RenameError("No references found at position".to_string()))?;
     let ref_edits = refs
         .references
         .into_iter()
         .map(|reference| source_edit_from_reference(reference, new_name));
     source_file_edits.extend(ref_edits);
 
-    Some(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
+    Ok(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
 }
 
 fn rename_to_self(
     sema: &Semantics<RootDatabase>,
     position: FilePosition,
-) -> Option<RangeInfo<SourceChange>> {
+) -> Result<RangeInfo<SourceChange>, RenameError> {
     let source_file = sema.parse(position.file_id);
     let syn = source_file.syntax();
 
-    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)?;
-    let params = fn_def.param_list()?;
+    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)
+        .ok_or_else(|| RenameError("No surrounding method declaration found".to_string()))?;
+    let params =
+        fn_def.param_list().ok_or_else(|| RenameError("Method has no parameters".to_string()))?;
     if params.self_param().is_some() {
-        return None; // method already has self param
+        return Err(RenameError("Method already has a self parameter".to_string()));
     }
-    let first_param = params.params().next()?;
+    let first_param =
+        params.params().next().ok_or_else(|| RenameError("Method has no parameters".into()))?;
     let mutable = match first_param.ty() {
         Some(ast::Type::RefType(rt)) => rt.mut_token().is_some(),
-        _ => return None, // not renaming other types
+        _ => return Err(RenameError("Not renaming other types".to_string())),
     };
 
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)
+        .ok_or_else(|| RenameError("No reference found at position".to_string()))?;
 
     let param_range = first_param.syntax().text_range();
     let (param_ref, usages): (Vec<Reference>, Vec<Reference>) = refs
@@ -169,7 +199,7 @@ fn rename_to_self(
         .partition(|reference| param_range.intersect(reference.file_range.range).is_some());
 
     if param_ref.is_empty() {
-        return None;
+        return Err(RenameError("Parameter to rename not found".to_string()));
     }
 
     let mut edits = usages
@@ -185,7 +215,7 @@ fn rename_to_self(
         ),
     });
 
-    Some(RangeInfo::new(range, SourceChange::from(edits)))
+    Ok(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn text_edit_from_self_param(
@@ -216,12 +246,13 @@ fn rename_self_to_param(
     position: FilePosition,
     self_token: SyntaxToken,
     new_name: &str,
-) -> Option<RangeInfo<SourceChange>> {
+) -> Result<RangeInfo<SourceChange>, RenameError> {
     let source_file = sema.parse(position.file_id);
     let syn = source_file.syntax();
 
     let text = sema.db.file_text(position.file_id);
-    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)?;
+    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)
+        .ok_or_else(|| RenameError("No surrounding method declaration found".to_string()))?;
     let search_range = fn_def.syntax().text_range();
 
     let mut edits: Vec<SourceFileEdit> = vec![];
@@ -235,7 +266,8 @@ fn rename_self_to_param(
             syn.token_at_offset(offset).find(|t| t.kind() == SyntaxKind::SELF_KW)
         {
             let edit = if let Some(ref self_param) = ast::SelfParam::cast(usage.parent()) {
-                text_edit_from_self_param(syn, self_param, new_name)?
+                text_edit_from_self_param(syn, self_param, new_name)
+                    .ok_or_else(|| RenameError("No target type found".to_string()))?
             } else {
                 TextEdit::replace(usage.text_range(), String::from(new_name))
             };
@@ -246,15 +278,18 @@ fn rename_self_to_param(
     let range = ast::SelfParam::cast(self_token.parent())
         .map_or(self_token.text_range(), |p| p.syntax().text_range());
 
-    Some(RangeInfo::new(range, SourceChange::from(edits)))
+    Ok(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn rename_reference(
     sema: &Semantics<RootDatabase>,
     position: FilePosition,
     new_name: &str,
-) -> Option<RangeInfo<SourceChange>> {
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+) -> Result<RangeInfo<SourceChange>, RenameError> {
+    let RangeInfo { range, info: refs } = match find_all_refs(sema, position, None) {
+        Some(range_info) => range_info,
+        None => return Err(RenameError("No references found at position".to_string())),
+    };
 
     let edit = refs
         .into_iter()
@@ -262,10 +297,10 @@ fn rename_reference(
         .collect::<Vec<_>>();
 
     if edit.is_empty() {
-        return None;
+        return Err(RenameError("No references found at position".to_string()));
     }
 
-    Some(RangeInfo::new(range, SourceChange::from(edit)))
+    Ok(RangeInfo::new(range, SourceChange::from(edit)))
 }
 
 #[cfg(test)]
@@ -280,25 +315,45 @@ mod tests {
     fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
         let ra_fixture_after = &trim_indent(ra_fixture_after);
         let (analysis, position) = fixture::position(ra_fixture_before);
-        let source_change = analysis.rename(position, new_name).unwrap();
-        let mut text_edit_builder = TextEdit::builder();
-        let mut file_id: Option<FileId> = None;
-        if let Some(change) = source_change {
-            for edit in change.info.source_file_edits {
-                file_id = Some(edit.file_id);
-                for indel in edit.edit.into_iter() {
-                    text_edit_builder.replace(indel.delete, indel.insert);
+        let rename_result = analysis
+            .rename(position, new_name)
+            .unwrap_or_else(|err| panic!("Rename to '{}' was cancelled: {}", new_name, err));
+        match rename_result {
+            Ok(source_change) => {
+                let mut text_edit_builder = TextEdit::builder();
+                let mut file_id: Option<FileId> = None;
+                for edit in source_change.info.source_file_edits {
+                    file_id = Some(edit.file_id);
+                    for indel in edit.edit.into_iter() {
+                        text_edit_builder.replace(indel.delete, indel.insert);
+                    }
                 }
+                let mut result = analysis.file_text(file_id.unwrap()).unwrap().to_string();
+                text_edit_builder.finish().apply(&mut result);
+                assert_eq_text!(ra_fixture_after, &*result);
             }
-        }
-        let mut result = analysis.file_text(file_id.unwrap()).unwrap().to_string();
-        text_edit_builder.finish().apply(&mut result);
-        assert_eq_text!(ra_fixture_after, &*result);
+            Err(err) => {
+                if ra_fixture_after.starts_with("error:") {
+                    let error_message = ra_fixture_after
+                        .chars()
+                        .into_iter()
+                        .skip("error:".len())
+                        .collect::<String>();
+                    assert_eq!(error_message.trim(), err.to_string());
+                    return;
+                } else {
+                    panic!("Rename to '{}' failed unexpectedly: {}", new_name, err)
+                }
+            }
+        };
     }
 
     fn check_expect(new_name: &str, ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let source_change = analysis.rename(position, new_name).unwrap().unwrap();
+        let source_change = analysis
+            .rename(position, new_name)
+            .unwrap()
+            .expect("Expect returned RangeInfo to be Some, but was None");
         expect.assert_debug_eq(&source_change)
     }
 
@@ -313,11 +368,30 @@ mod tests {
     }
 
     #[test]
-    fn test_rename_to_invalid_identifier() {
-        let (analysis, position) = fixture::position(r#"fn main() { let i<|> = 1; }"#);
-        let new_name = "invalid!";
-        let source_change = analysis.rename(position, new_name).unwrap();
-        assert!(source_change.is_none());
+    fn test_rename_to_invalid_identifier1() {
+        check(
+            "invalid!",
+            r#"fn main() { let i<|> = 1; }"#,
+            "error: Invalid name `invalid!`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier2() {
+        check(
+            "multiple tokens",
+            r#"fn main() { let i<|> = 1; }"#,
+            "error: Invalid name `multiple tokens`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier3() {
+        check(
+            "let",
+            r#"fn main() { let i<|> = 1; }"#,
+            "error: Invalid name `let`: not an identifier",
+        );
     }
 
     #[test]
@@ -350,6 +424,15 @@ fn main() {
     }
 
     #[test]
+    fn test_rename_unresolved_reference() {
+        check(
+            "new_name",
+            r#"fn main() { let _ = unresolved_ref<|>; }"#,
+            "error: No references found at position",
+        );
+    }
+
+    #[test]
     fn test_rename_for_macro_args() {
         check(
             "b",
diff --git a/crates/ide_db/src/search.rs b/crates/ide_db/src/search.rs
index edab1d644..8e3dcd99c 100644
--- a/crates/ide_db/src/search.rs
+++ b/crates/ide_db/src/search.rs
@@ -12,8 +12,9 @@ use once_cell::unsync::Lazy;
 use rustc_hash::FxHashMap;
 use syntax::{ast, match_ast, AstNode, TextRange, TextSize};
 
+use crate::defs::NameClass;
 use crate::{
-    defs::{classify_name_ref, Definition, NameRefClass},
+    defs::{classify_name, classify_name_ref, Definition, NameRefClass},
     RootDatabase,
 };
 
@@ -226,9 +227,9 @@ impl<'a> FindUsages<'a> {
 
         let search_scope = {
             let base = self.def.search_scope(sema.db);
-            match self.scope {
+            match &self.scope {
                 None => base,
-                Some(scope) => base.intersection(&scope),
+                Some(scope) => base.intersection(scope),
             }
         };
 
@@ -251,54 +252,83 @@ impl<'a> FindUsages<'a> {
                     continue;
                 }
 
-                let name_ref: ast::NameRef =
-                    match sema.find_node_at_offset_with_descend(&tree, offset) {
-                        Some(it) => it,
-                        None => continue,
-                    };
-
-                match classify_name_ref(&sema, &name_ref) {
-                    Some(NameRefClass::Definition(def)) if &def == self.def => {
-                        let kind = if is_record_lit_name_ref(&name_ref)
-                            || is_call_expr_name_ref(&name_ref)
-                        {
-                            ReferenceKind::StructLiteral
-                        } else {
-                            ReferenceKind::Other
-                        };
-
-                        let reference = Reference {
-                            file_range: sema.original_range(name_ref.syntax()),
-                            kind,
-                            access: reference_access(&def, &name_ref),
-                        };
-                        if sink(reference) {
+                match sema.find_node_at_offset_with_descend(&tree, offset) {
+                    Some(name_ref) => {
+                        if self.found_name_ref(&name_ref, sink) {
                             return;
                         }
                     }
-                    Some(NameRefClass::FieldShorthand { local, field }) => {
-                        let reference = match self.def {
-                            Definition::Field(_) if &field == self.def => Reference {
-                                file_range: self.sema.original_range(name_ref.syntax()),
-                                kind: ReferenceKind::FieldShorthandForField,
-                                access: reference_access(&field, &name_ref),
-                            },
-                            Definition::Local(l) if &local == l => Reference {
-                                file_range: self.sema.original_range(name_ref.syntax()),
-                                kind: ReferenceKind::FieldShorthandForLocal,
-                                access: reference_access(&Definition::Local(local), &name_ref),
-                            },
-                            _ => continue, // not a usage
-                        };
-                        if sink(reference) {
-                            return;
+                    None => match sema.find_node_at_offset_with_descend(&tree, offset) {
+                        Some(name) => {
+                            if self.found_name(&name, sink) {
+                                return;
+                            }
                         }
-                    }
-                    _ => {} // not a usage
+                        None => {}
+                    },
                 }
             }
         }
     }
+
+    fn found_name_ref(
+        &self,
+        name_ref: &ast::NameRef,
+        sink: &mut dyn FnMut(Reference) -> bool,
+    ) -> bool {
+        match classify_name_ref(self.sema, &name_ref) {
+            Some(NameRefClass::Definition(def)) if &def == self.def => {
+                let kind = if is_record_lit_name_ref(&name_ref) || is_call_expr_name_ref(&name_ref)
+                {
+                    ReferenceKind::StructLiteral
+                } else {
+                    ReferenceKind::Other
+                };
+
+                let reference = Reference {
+                    file_range: self.sema.original_range(name_ref.syntax()),
+                    kind,
+                    access: reference_access(&def, &name_ref),
+                };
+                sink(reference)
+            }
+            Some(NameRefClass::FieldShorthand { local, field }) => {
+                let reference = match self.def {
+                    Definition::Field(_) if &field == self.def => Reference {
+                        file_range: self.sema.original_range(name_ref.syntax()),
+                        kind: ReferenceKind::FieldShorthandForField,
+                        access: reference_access(&field, &name_ref),
+                    },
+                    Definition::Local(l) if &local == l => Reference {
+                        file_range: self.sema.original_range(name_ref.syntax()),
+                        kind: ReferenceKind::FieldShorthandForLocal,
+                        access: reference_access(&Definition::Local(local), &name_ref),
+                    },
+                    _ => return false, // not a usage
+                };
+                sink(reference)
+            }
+            _ => false, // not a usage
+        }
+    }
+
+    fn found_name(&self, name: &ast::Name, sink: &mut dyn FnMut(Reference) -> bool) -> bool {
+        match classify_name(self.sema, name) {
+            Some(NameClass::FieldShorthand { local: _, field }) => {
+                let reference = match self.def {
+                    Definition::Field(_) if &field == self.def => Reference {
+                        file_range: self.sema.original_range(name.syntax()),
+                        kind: ReferenceKind::FieldShorthandForField,
+                        // FIXME: mutable patterns should have `Write` access
+                        access: Some(ReferenceAccess::Read),
+                    },
+                    _ => return false, // not a usage
+                };
+                sink(reference)
+            }
+            _ => false, // not a usage
+        }
+    }
 }
 
 fn reference_access(def: &Definition, name_ref: &ast::NameRef) -> Option<ReferenceAccess> {
diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/client.rs b/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
index cb4b3bdb0..55d6330cc 100644
--- a/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
+++ b/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
@@ -160,6 +160,7 @@ macro_rules! define_handles {
 }
 define_handles! {
     'owned:
+    FreeFunctions,
     TokenStream,
     TokenStreamBuilder,
     TokenStreamIter,
diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs b/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
index aeb05aad4..b97886eb9 100644
--- a/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
+++ b/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
@@ -57,6 +57,10 @@ use std::thread;
 macro_rules! with_api {
     ($S:ident, $self:ident, $m:ident) => {
         $m! {
+            FreeFunctions {
+                fn drop($self: $S::FreeFunctions);
+                fn track_env_var(var: &str, value: Option<&str>);
+            },
             TokenStream {
                 fn drop($self: $S::TokenStream);
                 fn clone($self: &$S::TokenStream) -> $S::TokenStream;
diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/server.rs b/crates/proc_macro_srv/src/proc_macro/bridge/server.rs
index 45d41ac02..3acb239af 100644
--- a/crates/proc_macro_srv/src/proc_macro/bridge/server.rs
+++ b/crates/proc_macro_srv/src/proc_macro/bridge/server.rs
@@ -11,6 +11,8 @@ use super::client::HandleStore;
 /// Declare an associated item of one of the traits below, optionally
 /// adjusting it (i.e., adding bounds to types and default bodies to methods).
 macro_rules! associated_item {
+    (type FreeFunctions) =>
+        (type FreeFunctions: 'static;);
     (type TokenStream) =>
         (type TokenStream: 'static + Clone;);
     (type TokenStreamBuilder) =>
diff --git a/crates/proc_macro_srv/src/proc_macro/mod.rs b/crates/proc_macro_srv/src/proc_macro/mod.rs
index ee0dc9722..fc6e7344f 100644
--- a/crates/proc_macro_srv/src/proc_macro/mod.rs
+++ b/crates/proc_macro_srv/src/proc_macro/mod.rs
@@ -924,3 +924,25 @@ impl fmt::Debug for Literal {
         self.0.fmt(f)
     }
 }
+
+pub mod tracked_env {
+    use std::env::{self, VarError};
+    use std::ffi::OsStr;
+
+    /// Retrieve an environment variable and add it to build dependency info.
+    /// Build system executing the compiler will know that the variable was accessed during
+    /// compilation, and will be able to rerun the build when the value of that variable changes.
+    /// Besides the dependency tracking this function should be equivalent to `env::var` from the
+    /// standard library, except that the argument must be UTF-8.
+    pub fn var<K: AsRef<OsStr> + AsRef<str>>(key: K) -> Result<String, VarError> {
+        use std::ops::Deref;
+
+        let key: &str = key.as_ref();
+        let value = env::var(key);
+        super::bridge::client::FreeFunctions::track_env_var(
+            key,
+            value.as_ref().map(|t| t.deref()).ok(),
+        );
+        value
+    }
+}
diff --git a/crates/proc_macro_srv/src/rustc_server.rs b/crates/proc_macro_srv/src/rustc_server.rs
index 7d1695c86..c5fe3591e 100644
--- a/crates/proc_macro_srv/src/rustc_server.rs
+++ b/crates/proc_macro_srv/src/rustc_server.rs
@@ -242,6 +242,8 @@ impl TokenStreamBuilder {
     }
 }
 
+pub struct FreeFunctions;
+
 #[derive(Clone)]
 pub struct TokenStreamIter {
     trees: IntoIter<TokenTree>,
@@ -254,6 +256,7 @@ pub struct Rustc {
 }
 
 impl server::Types for Rustc {
+    type FreeFunctions = FreeFunctions;
     type TokenStream = TokenStream;
     type TokenStreamBuilder = TokenStreamBuilder;
     type TokenStreamIter = TokenStreamIter;
@@ -267,6 +270,13 @@ impl server::Types for Rustc {
     type MultiSpan = Vec<Span>;
 }
 
+impl server::FreeFunctions for Rustc {
+    fn track_env_var(&mut self, _var: &str, _value: Option<&str>) {
+        // FIXME: track env var accesses
+        // https://github.com/rust-lang/rust/pull/71858
+    }
+}
+
 impl server::TokenStream for Rustc {
     fn new(&mut self) -> Self::TokenStream {
         Self::TokenStream::new()
diff --git a/crates/profile/Cargo.toml b/crates/profile/Cargo.toml
index 261172d61..c5dfdff32 100644
--- a/crates/profile/Cargo.toml
+++ b/crates/profile/Cargo.toml
@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 once_cell = "1.3.1"
-cfg-if = "0.1.10"
+cfg-if = "1"
 libc = "0.2.73"
 backtrace = { version = "0.3.44", optional = true }
 
diff --git a/crates/project_model/src/sysroot.rs b/crates/project_model/src/sysroot.rs
index 871808d89..e529e07b0 100644
--- a/crates/project_model/src/sysroot.rs
+++ b/crates/project_model/src/sysroot.rs
@@ -90,9 +90,15 @@ impl Sysroot {
         }
 
         if sysroot.by_name("core").is_none() {
+            let var_note = if env::var_os("RUST_SRC_PATH").is_some() {
+                " (`RUST_SRC_PATH` might be incorrect, try unsetting it)"
+            } else {
+                ""
+            };
             anyhow::bail!(
-                "could not find libcore in sysroot path `{}`",
-                sysroot_src_dir.as_ref().display()
+                "could not find libcore in sysroot path `{}`{}",
+                sysroot_src_dir.as_ref().display(),
+                var_note,
             );
         }
 
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index ba73abcac..215be850f 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -646,14 +646,9 @@ pub(crate) fn handle_prepare_rename(
     let _p = profile::span("handle_prepare_rename");
     let position = from_proto::file_position(&snap, params)?;
 
-    let optional_change = snap.analysis.rename(position, "dummy")?;
-    let range = match optional_change {
-        None => return Ok(None),
-        Some(it) => it.range,
-    };
-
+    let change = snap.analysis.rename(position, "dummy")??;
     let line_index = snap.analysis.file_line_index(position.file_id)?;
-    let range = to_proto::range(&line_index, range);
+    let range = to_proto::range(&line_index, change.range);
     Ok(Some(PrepareRenameResponse::Range(range)))
 }
 
@@ -672,12 +667,8 @@ pub(crate) fn handle_rename(
         .into());
     }
 
-    let optional_change = snap.analysis.rename(position, &*params.new_name)?;
-    let source_change = match optional_change {
-        None => return Ok(None),
-        Some(it) => it.info,
-    };
-    let workspace_edit = to_proto::workspace_edit(&snap, source_change)?;
+    let change = snap.analysis.rename(position, &*params.new_name)??;
+    let workspace_edit = to_proto::workspace_edit(&snap, change.info)?;
     Ok(Some(workspace_edit))
 }
 
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 0b15f10e9..547fe9f47 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "681.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "682.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"