8 files changed, 157 insertions, 83 deletions

diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 514dcaf96..e90fbd428 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -466,7 +466,7 @@ impl Analysis {
         &self,
         position: FilePosition,
     ) -> Cancelable<Option<ReferenceSearchResult>> {
-        self.with_db(|db| references::find_all_refs(db, position))
+        self.with_db(|db| references::find_all_refs(db, position).map(|it| it.info))
     }
 
     /// Returns a short text describing element at position.
@@ -536,7 +536,7 @@ impl Analysis {
         &self,
         position: FilePosition,
         new_name: &str,
-    ) -> Cancelable<Option<SourceChange>> {
+    ) -> Cancelable<Option<RangeInfo<SourceChange>>> {
         self.with_db(|db| references::rename(db, position, new_name))
     }
 
diff --git a/crates/ra_ide_api/src/references.rs b/crates/ra_ide_api/src/references.rs
index d8a00067f..5f1f0efc3 100644
--- a/crates/ra_ide_api/src/references.rs
+++ b/crates/ra_ide_api/src/references.rs
@@ -4,7 +4,7 @@ use ra_syntax::{algo::find_node_at_offset, ast, AstNode, SourceFile, SyntaxNode}
 use relative_path::{RelativePath, RelativePathBuf};
 
 use crate::{
-    db::RootDatabase, FileId, FilePosition, FileRange, FileSystemEdit, NavigationTarget,
+    db::RootDatabase, FileId, FilePosition, FileRange, FileSystemEdit, NavigationTarget, RangeInfo,
     SourceChange, SourceFileEdit, TextRange,
 };
 
@@ -48,9 +48,9 @@ impl IntoIterator for ReferenceSearchResult {
 pub(crate) fn find_all_refs(
     db: &RootDatabase,
     position: FilePosition,
-) -> Option<ReferenceSearchResult> {
+) -> Option<RangeInfo<ReferenceSearchResult>> {
     let parse = db.parse(position.file_id);
-    let (binding, analyzer) = find_binding(db, &parse.tree(), position)?;
+    let RangeInfo { range, info: (binding, analyzer) } = find_binding(db, &parse.tree(), position)?;
     let declaration = NavigationTarget::from_bind_pat(position.file_id, &binding);
 
     let references = analyzer
@@ -59,24 +59,26 @@ pub(crate) fn find_all_refs(
         .map(move |ref_desc| FileRange { file_id: position.file_id, range: ref_desc.range })
         .collect::<Vec<_>>();
 
-    return Some(ReferenceSearchResult { declaration, references });
+    return Some(RangeInfo::new(range, ReferenceSearchResult { declaration, references }));
 
     fn find_binding<'a>(
         db: &RootDatabase,
         source_file: &SourceFile,
         position: FilePosition,
-    ) -> Option<(ast::BindPat, hir::SourceAnalyzer)> {
+    ) -> Option<RangeInfo<(ast::BindPat, hir::SourceAnalyzer)>> {
         let syntax = source_file.syntax();
         if let Some(binding) = find_node_at_offset::<ast::BindPat>(syntax, position.offset) {
+            let range = binding.syntax().text_range();
             let analyzer = hir::SourceAnalyzer::new(db, position.file_id, binding.syntax(), None);
-            return Some((binding, analyzer));
+            return Some(RangeInfo::new(range, (binding, analyzer)));
         };
         let name_ref = find_node_at_offset::<ast::NameRef>(syntax, position.offset)?;
+        let range = name_ref.syntax().text_range();
         let analyzer = hir::SourceAnalyzer::new(db, position.file_id, name_ref.syntax(), None);
         let resolved = analyzer.resolve_local_name(&name_ref)?;
         if let Either::A(ptr) = resolved.ptr() {
             if let ast::Pat::BindPat(binding) = ptr.to_node(source_file.syntax()) {
-                return Some((binding, analyzer));
+                return Some(RangeInfo::new(range, (binding, analyzer)));
             }
         }
         None
@@ -87,12 +89,14 @@ pub(crate) fn rename(
     db: &RootDatabase,
     position: FilePosition,
     new_name: &str,
-) -> Option<SourceChange> {
+) -> Option<RangeInfo<SourceChange>> {
     let parse = db.parse(position.file_id);
     if let Some((ast_name, ast_module)) =
         find_name_and_module_at_offset(parse.tree().syntax(), position)
     {
+        let range = ast_name.syntax().text_range();
         rename_mod(db, &ast_name, &ast_module, position, new_name)
+            .map(|info| RangeInfo::new(range, info))
     } else {
         rename_reference(db, position, new_name)
     }
@@ -107,7 +111,7 @@ fn find_name_and_module_at_offset(
     Some((ast_name, ast_module))
 }
 
-fn source_edit_from_fileid_range(
+fn source_edit_from_file_id_range(
     file_id: FileId,
     range: TextRange,
     new_name: &str,
@@ -179,19 +183,19 @@ fn rename_reference(
     db: &RootDatabase,
     position: FilePosition,
     new_name: &str,
-) -> Option<SourceChange> {
-    let refs = find_all_refs(db, position)?;
+) -> Option<RangeInfo<SourceChange>> {
+    let RangeInfo { range, info: refs } = find_all_refs(db, position)?;
 
     let edit = refs
         .into_iter()
-        .map(|range| source_edit_from_fileid_range(range.file_id, range.range, new_name))
+        .map(|range| source_edit_from_file_id_range(range.file_id, range.range, new_name))
         .collect::<Vec<_>>();
 
     if edit.is_empty() {
         return None;
     }
 
-    Some(SourceChange::source_file_edits("rename", edit))
+    Some(RangeInfo::new(range, SourceChange::source_file_edits("rename", edit)))
 }
 
 #[cfg(test)]
@@ -342,38 +346,43 @@ mod tests {
         let new_name = "foo2";
         let source_change = analysis.rename(position, new_name).unwrap();
         assert_debug_snapshot!(&source_change,
-@r#"Some(
-    SourceChange {
-        label: "rename",
-        source_file_edits: [
-            SourceFileEdit {
-                file_id: FileId(
-                    2,
-                ),
-                edit: TextEdit {
-                    atoms: [
-                        AtomTextEdit {
-                            delete: [4; 7),
-                            insert: "foo2",
+@r###"
+        Some(
+            RangeInfo {
+                range: [4; 7),
+                info: SourceChange {
+                    label: "rename",
+                    source_file_edits: [
+                        SourceFileEdit {
+                            file_id: FileId(
+                                2,
+                            ),
+                            edit: TextEdit {
+                                atoms: [
+                                    AtomTextEdit {
+                                        delete: [4; 7),
+                                        insert: "foo2",
+                                    },
+                                ],
+                            },
+                        },
+                    ],
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                3,
+                            ),
+                            dst_source_root: SourceRootId(
+                                0,
+                            ),
+                            dst_path: "bar/foo2.rs",
                         },
                     ],
+                    cursor_position: None,
                 },
             },
-        ],
-        file_system_edits: [
-            MoveFile {
-                src: FileId(
-                    3,
-                ),
-                dst_source_root: SourceRootId(
-                    0,
-                ),
-                dst_path: "bar/foo2.rs",
-            },
-        ],
-        cursor_position: None,
-    },
-)"#);
+        )
+        "###);
     }
 
     #[test]
@@ -389,38 +398,43 @@ mod tests {
         let new_name = "foo2";
         let source_change = analysis.rename(position, new_name).unwrap();
         assert_debug_snapshot!(&source_change,
-        @r###"Some(
-    SourceChange {
-        label: "rename",
-        source_file_edits: [
-            SourceFileEdit {
-                file_id: FileId(
-                    1,
-                ),
-                edit: TextEdit {
-                    atoms: [
-                        AtomTextEdit {
-                            delete: [4; 7),
-                            insert: "foo2",
+        @r###"
+        Some(
+            RangeInfo {
+                range: [4; 7),
+                info: SourceChange {
+                    label: "rename",
+                    source_file_edits: [
+                        SourceFileEdit {
+                            file_id: FileId(
+                                1,
+                            ),
+                            edit: TextEdit {
+                                atoms: [
+                                    AtomTextEdit {
+                                        delete: [4; 7),
+                                        insert: "foo2",
+                                    },
+                                ],
+                            },
+                        },
+                    ],
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                2,
+                            ),
+                            dst_source_root: SourceRootId(
+                                0,
+                            ),
+                            dst_path: "foo2/mod.rs",
                         },
                     ],
+                    cursor_position: None,
                 },
             },
-        ],
-        file_system_edits: [
-            MoveFile {
-                src: FileId(
-                    2,
-                ),
-                dst_source_root: SourceRootId(
-                    0,
-                ),
-                dst_path: "foo2/mod.rs",
-            },
-        ],
-        cursor_position: None,
-    },
-)"###
+        )
+        "###
                );
     }
 
@@ -430,7 +444,7 @@ mod tests {
         let mut text_edit_builder = ra_text_edit::TextEditBuilder::default();
         let mut file_id: Option<FileId> = None;
         if let Some(change) = source_change {
-            for edit in change.source_file_edits {
+            for edit in change.info.source_file_edits {
                 file_id = Some(edit.file_id);
                 for atom in edit.edit.as_atoms() {
                     text_edit_builder.replace(atom.delete, atom.insert.clone());
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index eb805a6d3..948d543ea 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -460,18 +460,16 @@ pub fn handle_prepare_rename(
 
     // We support renaming references like handle_rename does.
     // In the future we may want to reject the renaming of things like keywords here too.
-    let refs = match world.analysis().find_all_refs(position)? {
+    let optional_change = world.analysis().rename(position, "dummy")?;
+    let range = match optional_change {
         None => return Ok(None),
-        Some(refs) => refs,
+        Some(it) => it.range,
     };
 
-    // Refs should always have a declaration
-    let r = refs.declaration();
     let file_id = params.text_document.try_conv_with(&world)?;
     let line_index = world.analysis().file_line_index(file_id)?;
-    let loc = to_location(r.file_id(), r.range(), &world, &line_index)?;
-
-    Ok(Some(PrepareRenameResponse::Range(loc.range)))
+    let range = range.conv_with(&line_index);
+    Ok(Some(PrepareRenameResponse::Range(range)))
 }
 
 pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Option<WorkspaceEdit>> {
@@ -488,7 +486,7 @@ pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Optio
     let optional_change = world.analysis().rename(position, &*params.new_name)?;
     let change = match optional_change {
         None => return Ok(None),
-        Some(it) => it,
+        Some(it) => it.info,
     };
 
     let source_change_req = change.try_conv_with(&world)?;
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 6d426206e..b4327b78f 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -31,7 +31,7 @@ pub(super) enum ItemFlavor {
 
 pub(super) const ITEM_RECOVERY_SET: TokenSet = token_set![
     FN_KW, STRUCT_KW, ENUM_KW, IMPL_KW, TRAIT_KW, CONST_KW, STATIC_KW, LET_KW, MOD_KW, PUB_KW,
-    CRATE_KW
+    CRATE_KW, USE_KW
 ];
 
 pub(super) fn item_or_macro(p: &mut Parser, stop_on_r_curly: bool, flavor: ItemFlavor) {
diff --git a/crates/ra_parser/src/grammar/items/use_item.rs b/crates/ra_parser/src/grammar/items/use_item.rs
index c0c7d0ec6..83a65e226 100644
--- a/crates/ra_parser/src/grammar/items/use_item.rs
+++ b/crates/ra_parser/src/grammar/items/use_item.rs
@@ -101,7 +101,10 @@ fn use_tree(p: &mut Parser) {
         }
         _ => {
             m.abandon(p);
-            p.err_and_bump("expected one of `*`, `::`, `{`, `self`, `super` or an indentifier");
+            p.err_recover(
+                "expected one of `*`, `::`, `{`, `self`, `super` or an identifier",
+                ITEM_RECOVERY_SET,
+            );
             return;
         }
     }
diff --git a/crates/ra_syntax/test_data/parser/err/0002_duplicate_shebang.txt b/crates/ra_syntax/test_data/parser/err/0002_duplicate_shebang.txt
index 84867026f..bdb5fa6c5 100644
--- a/crates/ra_syntax/test_data/parser/err/0002_duplicate_shebang.txt
+++ b/crates/ra_syntax/test_data/parser/err/0002_duplicate_shebang.txt
@@ -28,7 +28,7 @@ SOURCE_FILE@[0; 42)
   WHITESPACE@[41; 42) "\n"
 error 23: expected `[`
 error 23: expected an item
-error 27: expected one of `*`, `::`, `{`, `self`, `super` or an indentifier
+error 27: expected one of `*`, `::`, `{`, `self`, `super` or an identifier
 error 28: expected SEMI
 error 31: expected EXCL
 error 31: expected `{`, `[`, `(`
diff --git a/crates/ra_syntax/test_data/parser/err/0035_use_recover.rs b/crates/ra_syntax/test_data/parser/err/0035_use_recover.rs
new file mode 100644
index 000000000..4a2668126
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0035_use_recover.rs
@@ -0,0 +1,5 @@
+use foo::bar;
+use
+use crate::baz;
+use
+fn f() {}
diff --git a/crates/ra_syntax/test_data/parser/err/0035_use_recover.txt b/crates/ra_syntax/test_data/parser/err/0035_use_recover.txt
new file mode 100644
index 000000000..636840828
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0035_use_recover.txt
@@ -0,0 +1,54 @@
+SOURCE_FILE@[0; 48)
+  USE_ITEM@[0; 13)
+    USE_KW@[0; 3) "use"
+    WHITESPACE@[3; 4) " "
+    USE_TREE@[4; 12)
+      PATH@[4; 12)
+        PATH@[4; 7)
+          PATH_SEGMENT@[4; 7)
+            NAME_REF@[4; 7)
+              IDENT@[4; 7) "foo"
+        COLONCOLON@[7; 9) "::"
+        PATH_SEGMENT@[9; 12)
+          NAME_REF@[9; 12)
+            IDENT@[9; 12) "bar"
+    SEMI@[12; 13) ";"
+  WHITESPACE@[13; 14) "\n"
+  USE_ITEM@[14; 17)
+    USE_KW@[14; 17) "use"
+  WHITESPACE@[17; 18) "\n"
+  USE_ITEM@[18; 33)
+    USE_KW@[18; 21) "use"
+    WHITESPACE@[21; 22) " "
+    USE_TREE@[22; 32)
+      PATH@[22; 32)
+        PATH@[22; 27)
+          PATH_SEGMENT@[22; 27)
+            CRATE_KW@[22; 27) "crate"
+        COLONCOLON@[27; 29) "::"
+        PATH_SEGMENT@[29; 32)
+          NAME_REF@[29; 32)
+            IDENT@[29; 32) "baz"
+    SEMI@[32; 33) ";"
+  WHITESPACE@[33; 34) "\n"
+  USE_ITEM@[34; 37)
+    USE_KW@[34; 37) "use"
+  WHITESPACE@[37; 38) "\n"
+  FN_DEF@[38; 47)
+    FN_KW@[38; 40) "fn"
+    WHITESPACE@[40; 41) " "
+    NAME@[41; 42)
+      IDENT@[41; 42) "f"
+    PARAM_LIST@[42; 44)
+      L_PAREN@[42; 43) "("
+      R_PAREN@[43; 44) ")"
+    WHITESPACE@[44; 45) " "
+    BLOCK_EXPR@[45; 47)
+      BLOCK@[45; 47)
+        L_CURLY@[45; 46) "{"
+        R_CURLY@[46; 47) "}"
+  WHITESPACE@[47; 48) "\n"
+error 17: expected one of `*`, `::`, `{`, `self`, `super` or an identifier
+error 17: expected SEMI
+error 37: expected one of `*`, `::`, `{`, `self`, `super` or an identifier
+error 37: expected SEMI