7 files changed, 276 insertions, 38 deletions

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 3df73ed4f..9d3d88289 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -142,6 +142,15 @@ pub(crate) fn diagnostics(
                     .with_code(Some(d.code())),
             );
         })
+        .on::<hir::diagnostics::UnresolvedProcMacro, _>(|d| {
+            // Use more accurate position if available.
+            let display_range =
+                d.precise_location.unwrap_or_else(|| sema.diagnostics_display_range(d).range);
+
+            // FIXME: it would be nice to tell the user whether proc macros are currently disabled
+            res.borrow_mut()
+                .push(Diagnostic::hint(display_range, d.message()).with_code(Some(d.code())));
+        })
         // Only collect experimental diagnostics when they're enabled.
         .filter(|diag| !(diag.is_experimental() && config.disable_experimental))
         .filter(|diag| !config.disabled.contains(diag.code().as_str()));
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index 15792f947..b9810457f 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -1,14 +1,10 @@
 use hir::Semantics;
 use ide_db::{
+    base_db::FileId,
     defs::{NameClass, NameRefClass},
     symbol_index, RootDatabase,
 };
-use syntax::{
-    ast::{self},
-    match_ast, AstNode,
-    SyntaxKind::*,
-    SyntaxToken, TokenAtOffset, T,
-};
+use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
 
 use crate::{
     display::{ToNav, TryToNav},
@@ -44,6 +40,19 @@ pub(crate) fn goto_definition(
                 let nav = def.try_to_nav(sema.db)?;
                 vec![nav]
             },
+            ast::SelfParam(self_param) => {
+                vec![self_to_nav_target(self_param, position.file_id)?]
+            },
+            ast::PathSegment(segment) => {
+                segment.self_token()?;
+                let path = segment.parent_path();
+                if path.qualifier().is_some() && !ast::PathExpr::can_cast(path.syntax().parent()?.kind()) {
+                    return None;
+                }
+                let func = segment.syntax().ancestors().find_map(ast::Fn::cast)?;
+                let self_param = func.param_list()?.self_param()?;
+                vec![self_to_nav_target(self_param, position.file_id)?]
+            },
             _ => return None,
         }
     };
@@ -62,6 +71,20 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
     }
 }
 
+fn self_to_nav_target(self_param: ast::SelfParam, file_id: FileId) -> Option<NavigationTarget> {
+    let self_token = self_param.self_token()?;
+    Some(NavigationTarget {
+        file_id,
+        full_range: self_param.syntax().text_range(),
+        focus_range: Some(self_token.text_range()),
+        name: self_token.text().clone(),
+        kind: self_token.kind(),
+        container_name: None,
+        description: None,
+        docs: None,
+    })
+}
+
 #[derive(Debug)]
 pub(crate) enum ReferenceResult {
     Exact(NavigationTarget),
@@ -984,4 +1007,33 @@ fn g() -> <() as Iterator<A = (), B<|> = u8>>::A {}
 "#,
         );
     }
+
+    #[test]
+    fn goto_self_param_ty_specified() {
+        check(
+            r#"
+struct Foo {}
+
+impl Foo {
+    fn bar(self: &Foo) {
+         //^^^^
+        let foo = sel<|>f;
+    }
+}"#,
+        )
+    }
+
+    #[test]
+    fn goto_self_param_on_decl() {
+        check(
+            r#"
+struct Foo {}
+
+impl Foo {
+    fn bar(&self<|>) {
+          //^^^^
+    }
+}"#,
+        )
+    }
 }
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 832192881..94ad800a0 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -139,14 +139,17 @@ pub(crate) fn hover(
         }
     }
 
-    let node = token
-        .ancestors()
-        .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())?;
+    let node = token.ancestors().find(|n| {
+        ast::Expr::can_cast(n.kind())
+            || ast::Pat::can_cast(n.kind())
+            || ast::SelfParam::can_cast(n.kind())
+    })?;
 
     let ty = match_ast! {
         match node {
             ast::Expr(it) => sema.type_of_expr(&it)?,
             ast::Pat(it) => sema.type_of_pat(&it)?,
+            ast::SelfParam(self_param) => sema.type_of_self(&self_param)?,
             // If this node is a MACRO_CALL, it means that `descend_into_macros` failed to resolve.
             // (e.g expanding a builtin macro). So we give up here.
             ast::MacroCall(_it) => return None,
@@ -3282,4 +3285,41 @@ fn main() {
             "#]],
         );
     }
+
+    #[test]
+    fn hover_self_param_shows_type() {
+        check(
+            r#"
+struct Foo {}
+impl Foo {
+    fn bar(&sel<|>f) {}
+}
+"#,
+            expect![[r#"
+                *&self*
+                ```rust
+                &Foo
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_self_param_shows_type_for_arbitrary_self_type() {
+        check(
+            r#"
+struct Arc<T>(T);
+struct Foo {}
+impl Foo {
+    fn bar(sel<|>f: Arc<Foo>) {}
+}
+"#,
+            expect![[r#"
+                *self: Arc<Foo>*
+                ```rust
+                Arc<Foo>
+                ```
+            "#]],
+        );
+    }
 }
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index 6cfb22e13..65df7979c 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -1,6 +1,6 @@
-use assists::utils::FamousDefs;
 use either::Either;
 use hir::{known, Callable, HirDisplay, Semantics};
+use ide_db::helpers::FamousDefs;
 use ide_db::RootDatabase;
 use stdx::to_lower_snake_case;
 use syntax::{
@@ -427,8 +427,8 @@ fn get_callable(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<hir:
 
 #[cfg(test)]
 mod tests {
-    use assists::utils::FamousDefs;
     use expect_test::{expect, Expect};
+    use ide_db::helpers::FamousDefs;
     use test_utils::extract_annotations;
 
     use crate::{fixture, inlay_hints::InlayHintsConfig};
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 6288f7ea7..5244bdd61 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -87,9 +87,7 @@ pub use ide_db::{
     search::{Reference, ReferenceAccess, ReferenceKind},
 };
 
-pub use assists::{
-    utils::MergeBehaviour, Assist, AssistConfig, AssistId, AssistKind, ResolvedAssist,
-};
+pub use assists::{Assist, AssistConfig, AssistId, AssistKind, ResolvedAssist};
 pub use hir::{Documentation, Semantics};
 pub use ide_db::base_db::{
     Canceled, Change, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRoot,
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index b8725693a..731457696 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -1,4 +1,9 @@
 //! FIXME: write short doc here
+use std::{
+    convert::TryInto,
+    error::Error,
+    fmt::{self, Display},
+};
 
 use hir::{Module, ModuleDef, ModuleSource, Semantics};
 use ide_db::base_db::{FileRange, SourceDatabaseExt};
@@ -6,12 +11,6 @@ use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
 };
-
-use std::{
-    convert::TryInto,
-    error::Error,
-    fmt::{self, Display},
-};
 use syntax::{
     algo::find_node_at_offset,
     ast::{self, NameOwner},
@@ -222,24 +221,47 @@ fn rename_to_self(
     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 (fn_def, fn_ast) = find_node_at_offset::<ast::Fn>(syn, position.offset)
+        .and_then(|fn_ast| sema.to_def(&fn_ast).zip(Some(fn_ast)))
         .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() {
+    let param_range = fn_ast
+        .param_list()
+        .and_then(|p| p.params().next())
+        .ok_or_else(|| RenameError("Method has no parameters".to_string()))?
+        .syntax()
+        .text_range();
+    if !param_range.contains(position.offset) {
+        return Err(RenameError("Only the first parameter can be self".to_string()));
+    }
+
+    let impl_block = find_node_at_offset::<ast::Impl>(syn, position.offset)
+        .and_then(|def| sema.to_def(&def))
+        .ok_or_else(|| RenameError("No impl block found for function".to_string()))?;
+    if fn_def.self_param(sema.db).is_some() {
         return Err(RenameError("Method already has a self parameter".to_string()));
     }
+
+    let params = fn_def.params(sema.db);
     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 Err(RenameError("Not renaming other types".to_string())),
+        params.first().ok_or_else(|| RenameError("Method has no parameters".into()))?;
+    let first_param_ty = first_param.ty();
+    let impl_ty = impl_block.target_ty(sema.db);
+    let (ty, self_param) = if impl_ty.remove_ref().is_some() {
+        // if the impl is a ref to the type we can just match the `&T` with self directly
+        (first_param_ty.clone(), "self")
+    } else {
+        first_param_ty.remove_ref().map_or((first_param_ty.clone(), "self"), |ty| {
+            (ty, if first_param_ty.is_mutable_reference() { "&mut self" } else { "&self" })
+        })
     };
 
+    if ty != impl_ty {
+        return Err(RenameError("Parameter type differs from impl block type".to_string()));
+    }
+
     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
         .into_iter()
         .partition(|reference| param_range.intersect(reference.file_range.range).is_some());
@@ -255,10 +277,7 @@ fn rename_to_self(
 
     edits.push(SourceFileEdit {
         file_id: position.file_id,
-        edit: TextEdit::replace(
-            param_range,
-            String::from(if mutable { "&mut self" } else { "&self" }),
-        ),
+        edit: TextEdit::replace(param_range, String::from(self_param)),
     });
 
     Ok(RangeInfo::new(range, SourceChange::from(edits)))
@@ -281,7 +300,11 @@ fn text_edit_from_self_param(
 
     let mut replacement_text = String::from(new_name);
     replacement_text.push_str(": ");
-    replacement_text.push_str(self_param.mut_token().map_or("&", |_| "&mut "));
+    match (self_param.amp_token(), self_param.mut_token()) {
+        (None, None) => (),
+        (Some(_), None) => replacement_text.push('&'),
+        (_, Some(_)) => replacement_text.push_str("&mut "),
+    };
     replacement_text.push_str(type_name.as_str());
 
     Some(TextEdit::replace(self_param.syntax().text_range(), replacement_text))
@@ -1083,6 +1106,95 @@ impl Foo {
 }
 "#,
         );
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo<|>: Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_error_no_impl() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+fn f(foo<|>: &mut Foo) -> i32 {
+    foo.i
+}
+"#,
+            "error: No impl block found for function",
+        );
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+struct Bar;
+
+impl Bar {
+    fn f(foo<|>: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            "error: Parameter type differs from impl block type",
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_error_not_first() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+impl Foo {
+    fn f(x: (), foo<|>: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            "error: Only the first parameter can be self",
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_impl_ref() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+impl &Foo {
+    fn f(foo<|>: &Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+impl &Foo {
+    fn f(self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
     }
 
     #[test]
@@ -1111,6 +1223,31 @@ impl Foo {
     }
 
     #[test]
+    fn test_owned_self_to_parameter() {
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(<|>self) -> i32 {
+        self.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
     fn test_self_in_path_to_parameter() {
         check(
             "foo",
diff --git a/crates/ide/src/status.rs b/crates/ide/src/status.rs
index 8e91c99d7..e10d7c3a4 100644
--- a/crates/ide/src/status.rs
+++ b/crates/ide/src/status.rs
@@ -1,6 +1,6 @@
 use std::{fmt, iter::FromIterator, sync::Arc};
 
-use hir::MacroFile;
+use hir::{ExpandResult, MacroFile};
 use ide_db::base_db::{
     salsa::debug::{DebugQueryTable, TableEntry},
     CrateId, FileId, FileTextQuery, SourceDatabase, SourceRootId,
@@ -19,7 +19,7 @@ fn syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
     ide_db::base_db::ParseQuery.in_db(db).entries::<SyntaxTreeStats>()
 }
 fn macro_syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
-    hir::db::ParseMacroQuery.in_db(db).entries::<SyntaxTreeStats>()
+    hir::db::ParseMacroExpansionQuery.in_db(db).entries::<SyntaxTreeStats>()
 }
 
 // Feature: Status
@@ -115,10 +115,12 @@ impl FromIterator<TableEntry<FileId, Parse<ast::SourceFile>>> for SyntaxTreeStat
     }
 }
 
-impl<M> FromIterator<TableEntry<MacroFile, Option<(Parse<SyntaxNode>, M)>>> for SyntaxTreeStats {
+impl<M> FromIterator<TableEntry<MacroFile, ExpandResult<Option<(Parse<SyntaxNode>, M)>>>>
+    for SyntaxTreeStats
+{
     fn from_iter<T>(iter: T) -> SyntaxTreeStats
     where
-        T: IntoIterator<Item = TableEntry<MacroFile, Option<(Parse<SyntaxNode>, M)>>>,
+        T: IntoIterator<Item = TableEntry<MacroFile, ExpandResult<Option<(Parse<SyntaxNode>, M)>>>>,
     {
         let mut res = SyntaxTreeStats::default();
         for entry in iter {