12 files changed, 462 insertions, 73 deletions

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index e7e0d599e..3a2bdb4a6 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -20,6 +20,7 @@ jobs:
       RUN_SLOW_TESTS: 1
       RUSTUP_MAX_RETRIES: 10
       CARGO_NET_RETRY: 10
+      PROFILE: debug
     steps:
 
       - name: Checkout repository
@@ -75,8 +76,7 @@ jobs:
 
       - name: Prepare cache 2
         if: matrix.os == 'windows-latest'
-        run: Remove-Item ./target/debug/xtask.exe
-
+        run: Remove-Item ./target/${{ env.PROFILE }}/xtask.exe
 
   type-script:
     name: TypeScript
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
new file mode 100644
index 000000000..6cb27482d
--- /dev/null
+++ b/.github/workflows/release.yaml
@@ -0,0 +1,124 @@
+name: CI-Release
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+jobs:
+  rust:
+    name: Rust
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    env:
+      RUSTFLAGS: -D warnings
+      CARGO_INCREMENTAL: 0
+      RUN_SLOW_TESTS: 1
+      RUSTUP_MAX_RETRIES: 10
+      CARGO_NET_RETRY: 10
+      PROFILE: release
+    steps:
+
+      - name: Checkout repository
+        uses: actions/checkout@v1
+
+      # We need to disable the existing toolchain to avoid updating rust-docs
+      # which takes a long time. The fastest way to do this is to rename the
+      # existing folder, as deleting it takes about as much time as not doing
+      # anything and just updating rust-docs.
+      - name: Rename existing rust toolchain (Windows)
+        if: matrix.os == 'windows-latest'
+        run: Rename-Item C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc.old
+
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          override: true
+          components: rustfmt, rust-src
+
+      - name: Cache cargo registry
+        uses: actions/cache@v1
+        with:
+          path: ~/.cargo/registry
+          key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Cache cargo index
+        uses: actions/cache@v1
+        with:
+          path: ~/.cargo/git
+          key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Cache cargo target dir
+        uses: actions/cache@v1
+        with:
+          path: target
+          key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Compile and Test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --release --all-targets
+
+      - name: Prepare cache
+        run: cargo xtask pre-cache
+
+      - name: Prepare cache 2
+        if: matrix.os == 'windows-latest'
+        run: Remove-Item ./target/${{ env.PROFILE }}/xtask.exe
+
+      - name: Creat distribution dir
+        run: mkdir ./dist
+
+      - name: Copy binaries (non-win)
+        if: matrix.os != 'windows-latest'
+        run: cp ./target/${{ env.PROFILE }}/ra_lsp_server ./dist
+
+      - name: Copy binaries (win)
+        if: matrix.os == 'windows-latest'
+        run: copy ./target/${{ env.PROFILE }}/ra_lsp_server.* ./dist
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v1
+        with:
+          name: server-${{ matrix.os }}
+          path: ./dist
+
+  type-script:
+    name: TypeScript
+    runs-on: ubuntu-latest
+    env:
+      CXX: g++-4.9
+      CC: gcc-4.9
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v1
+
+      - name: Install Nodejs
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+
+      - run: npm ci
+        working-directory: ./editors/code
+      - run: npm run package --scripts-prepend-node-path
+        working-directory: ./editors/code
+
+      - name: Create distribution directory
+        run: mkdir ./dist
+
+      - name: Copy vscode extension
+        run: mkdir ./dist/code && cp ./editors/code/*.vsix ./dist/code/
+
+      - name: Copy emacs mode
+        run: cp -R ./editors/emacs ./dist/
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v1
+        with:
+          name: editors
+          path: ./dist
diff --git a/Cargo.toml b/Cargo.toml
index 97508c57b..3753a4143 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,8 @@ debug = 0
 
 [profile.release]
 incremental = true
+lto = true
+codegen-units = 1
 debug = 0 # set this to 1 or 2 to get more useful backtraces in debugger
 
 [patch.'crates-io']
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index 2c119269c..e9e275670 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -62,8 +62,13 @@ register_builtin! {
 }
 
 fn to_line_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
-    // FIXME: Use expansion info
     let file_id = file.original_file(db);
+
+    // FIXME: if the file is coming from macro, we return a dummy value for now.
+    if file.call_node(db).map(|it| it.file_id != file_id.into()).unwrap_or(true) {
+        return 0;
+    }
+
     let text = db.file_text(file_id);
     let mut line_num = 1;
 
@@ -150,8 +155,11 @@ fn option_env_expand(
 }
 
 fn to_col_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
-    // FIXME: Use expansion info
     let file_id = file.original_file(db);
+    // FIXME: if the file is coming from macro, we return a dummy value for now.
+    if file.call_node(db).map(|it| it.file_id != file_id.into()).unwrap_or(true) {
+        return 0;
+    }
     let text = db.file_text(file_id);
 
     let pos = pos.to_usize();
diff --git a/crates/ra_hir_expand/src/db.rs b/crates/ra_hir_expand/src/db.rs
index 5d12c1584..af5b22d1c 100644
--- a/crates/ra_hir_expand/src/db.rs
+++ b/crates/ra_hir_expand/src/db.rs
@@ -190,7 +190,6 @@ fn to_fragment_kind(db: &dyn AstDatabase, macro_call_id: MacroCallId) -> Fragmen
         TUPLE_EXPR => FragmentKind::Expr,
         PAREN_EXPR => FragmentKind::Expr,
 
-        // FIXME: Add tests for following cases in hir_ty
         FOR_EXPR => FragmentKind::Expr,
         PATH_EXPR => FragmentKind::Expr,
         LAMBDA_EXPR => FragmentKind::Expr,
diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index 69c695cc8..9d09d93a7 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -136,6 +136,87 @@ fn main() {
 }
 
 #[test]
+fn expr_macro_expanded_in_various_places() {
+    assert_snapshot!(
+        infer(r#"
+macro_rules! spam {
+    () => (1isize);
+}
+
+fn spam() {
+    spam!();
+    (spam!());
+    spam!().spam(spam!());
+    for _ in spam!() {}
+    || spam!();
+    while spam!() {}
+    break spam!();
+    return spam!();
+    match spam!() {
+        _ if spam!() => spam!(),
+    }
+    spam!()(spam!());
+    Spam { spam: spam!() };
+    spam!()[spam!()];
+    await spam!();
+    spam!() as usize;
+    &spam!();
+    -spam!();
+    spam!()..spam!();
+    spam!() + spam!();
+}
+"#),
+        @r###"
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    ![0; 6) '1isize': isize
+    [54; 457) '{     ...!(); }': !
+    [88; 109) 'spam!(...am!())': {unknown}
+    [115; 134) 'for _ ...!() {}': ()
+    [119; 120) '_': {unknown}
+    [132; 134) '{}': ()
+    [139; 149) '|| spam!()': || -> isize
+    [155; 171) 'while ...!() {}': ()
+    [169; 171) '{}': ()
+    [176; 189) 'break spam!()': !
+    [195; 209) 'return spam!()': !
+    [215; 269) 'match ...     }': isize
+    [239; 240) '_': isize
+    [274; 290) 'spam!(...am!())': {unknown}
+    [296; 318) 'Spam {...m!() }': {unknown}
+    [324; 340) 'spam!(...am!()]': {unknown}
+    [365; 381) 'spam!(... usize': usize
+    [387; 395) '&spam!()': &isize
+    [401; 409) '-spam!()': isize
+    [415; 431) 'spam!(...pam!()': {unknown}
+    [437; 454) 'spam!(...pam!()': isize
+    "###
+    );
+}
+
+#[test]
 fn infer_type_value_macro_having_same_name() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 7b187eba3..4d8deb21c 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -75,7 +75,9 @@ pub use crate::{
     inlay_hints::{InlayHint, InlayKind},
     line_index::{LineCol, LineIndex},
     line_index_utils::translate_offset_with_edit,
-    references::{Reference, ReferenceKind, ReferenceSearchResult, SearchScope},
+    references::{
+        Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult, SearchScope,
+    },
     runnables::{Runnable, RunnableKind},
     source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
     syntax_highlighting::HighlightedRange,
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index 5a3ec4eb9..4e52e0e7b 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -19,8 +19,9 @@ use once_cell::unsync::Lazy;
 use ra_db::{SourceDatabase, SourceDatabaseExt};
 use ra_prof::profile;
 use ra_syntax::{
-    algo::find_node_at_offset, ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, TextUnit,
-    TokenAtOffset,
+    algo::find_node_at_offset,
+    ast::{self, NameOwner},
+    match_ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange, TextUnit, TokenAtOffset,
 };
 
 use crate::{
@@ -37,15 +38,22 @@ pub use self::search_scope::SearchScope;
 
 #[derive(Debug, Clone)]
 pub struct ReferenceSearchResult {
-    declaration: NavigationTarget,
-    declaration_kind: ReferenceKind,
+    declaration: Declaration,
     references: Vec<Reference>,
 }
 
 #[derive(Debug, Clone)]
+pub struct Declaration {
+    pub nav: NavigationTarget,
+    pub kind: ReferenceKind,
+    pub access: Option<ReferenceAccess>,
+}
+
+#[derive(Debug, Clone)]
 pub struct Reference {
     pub file_range: FileRange,
     pub kind: ReferenceKind,
+    pub access: Option<ReferenceAccess>,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -54,11 +62,21 @@ pub enum ReferenceKind {
     Other,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum ReferenceAccess {
+    Read,
+    Write,
+}
+
 impl ReferenceSearchResult {
-    pub fn declaration(&self) -> &NavigationTarget {
+    pub fn declaration(&self) -> &Declaration {
         &self.declaration
     }
 
+    pub fn decl_target(&self) -> &NavigationTarget {
+        &self.declaration.nav
+    }
+
     pub fn references(&self) -> &[Reference] {
         &self.references
     }
@@ -72,7 +90,7 @@ impl ReferenceSearchResult {
 }
 
 // allow turning ReferenceSearchResult into an iterator
-// over FileRanges
+// over References
 impl IntoIterator for ReferenceSearchResult {
     type Item = Reference;
     type IntoIter = std::vec::IntoIter<Reference>;
@@ -81,10 +99,11 @@ impl IntoIterator for ReferenceSearchResult {
         let mut v = Vec::with_capacity(self.len());
         v.push(Reference {
             file_range: FileRange {
-                file_id: self.declaration.file_id(),
-                range: self.declaration.range(),
+                file_id: self.declaration.nav.file_id(),
+                range: self.declaration.nav.range(),
             },
-            kind: self.declaration_kind,
+            kind: self.declaration.kind,
+            access: self.declaration.access,
         });
         v.append(&mut self.references);
         v.into_iter()
@@ -131,15 +150,20 @@ pub(crate) fn find_all_refs(
         }
     };
 
+    let decl_range = declaration.range();
+
+    let declaration = Declaration {
+        nav: declaration,
+        kind: ReferenceKind::Other,
+        access: decl_access(&def.kind, &name, &syntax, decl_range),
+    };
+
     let references = process_definition(db, def, name, search_scope)
         .into_iter()
         .filter(|r| search_kind == ReferenceKind::Other || search_kind == r.kind)
         .collect();
 
-    Some(RangeInfo::new(
-        range,
-        ReferenceSearchResult { declaration, references, declaration_kind: ReferenceKind::Other },
-    ))
+    Some(RangeInfo::new(range, ReferenceSearchResult { declaration, references }))
 }
 
 fn find_name<'a>(
@@ -201,7 +225,12 @@ fn process_definition(
                         } else {
                             ReferenceKind::Other
                         };
-                        refs.push(Reference { file_range: FileRange { file_id, range }, kind });
+
+                        refs.push(Reference {
+                            file_range: FileRange { file_id, range },
+                            kind,
+                            access: reference_access(&d.kind, &name_ref),
+                        });
                     }
                 }
             }
@@ -210,11 +239,69 @@ fn process_definition(
     refs
 }
 
+fn decl_access(
+    kind: &NameKind,
+    name: &str,
+    syntax: &SyntaxNode,
+    range: TextRange,
+) -> Option<ReferenceAccess> {
+    match kind {
+        NameKind::Local(_) | NameKind::Field(_) => {}
+        _ => return None,
+    };
+
+    let stmt = find_node_at_offset::<ast::LetStmt>(syntax, range.start())?;
+    if let Some(_) = stmt.initializer() {
+        let pat = stmt.pat()?;
+        match pat {
+            ast::Pat::BindPat(it) => {
+                if it.name()?.text().as_str() == name {
+                    return Some(ReferenceAccess::Write);
+                }
+            }
+            _ => {}
+        }
+    }
+
+    None
+}
+
+fn reference_access(kind: &NameKind, name_ref: &ast::NameRef) -> Option<ReferenceAccess> {
+    // Only Locals and Fields have accesses for now.
+    match kind {
+        NameKind::Local(_) | NameKind::Field(_) => {}
+        _ => return None,
+    };
+
+    let mode = name_ref.syntax().ancestors().find_map(|node| {
+        match_ast! {
+            match (node) {
+                ast::BinExpr(expr) => {
+                    if expr.op_kind()?.is_assignment() {
+                        // If the variable or field ends on the LHS's end then it's a Write (covers fields and locals).
+                        // FIXME: This is not terribly accurate.
+                        if let Some(lhs) = expr.lhs() {
+                            if lhs.syntax().text_range().end() == name_ref.syntax().text_range().end() {
+                                return Some(ReferenceAccess::Write);
+                            }
+                        }
+                    }
+                    return Some(ReferenceAccess::Read);
+                },
+                _ => {None}
+            }
+        }
+    });
+
+    // Default Locals and Fields to read
+    mode.or(Some(ReferenceAccess::Read))
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{
         mock_analysis::{analysis_and_position, single_file_with_position, MockAnalysis},
-        Reference, ReferenceKind, ReferenceSearchResult, SearchScope,
+        Declaration, Reference, ReferenceSearchResult, SearchScope,
     };
 
     #[test]
@@ -234,8 +321,7 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(1) [5; 39) [12; 15)",
-            ReferenceKind::Other,
+            "Foo STRUCT_DEF FileId(1) [5; 39) [12; 15) Other",
             &["FileId(1) [142; 145) StructLiteral"],
         );
     }
@@ -258,13 +344,12 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "i BIND_PAT FileId(1) [33; 34)",
-            ReferenceKind::Other,
+            "i BIND_PAT FileId(1) [33; 34) Other Write",
             &[
-                "FileId(1) [67; 68) Other",
-                "FileId(1) [71; 72) Other",
-                "FileId(1) [101; 102) Other",
-                "FileId(1) [127; 128) Other",
+                "FileId(1) [67; 68) Other Write",
+                "FileId(1) [71; 72) Other Read",
+                "FileId(1) [101; 102) Other Write",
+                "FileId(1) [127; 128) Other Write",
             ],
         );
     }
@@ -279,9 +364,8 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "i BIND_PAT FileId(1) [12; 13)",
-            ReferenceKind::Other,
-            &["FileId(1) [38; 39) Other"],
+            "i BIND_PAT FileId(1) [12; 13) Other",
+            &["FileId(1) [38; 39) Other Read"],
         );
     }
 
@@ -295,9 +379,8 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "i BIND_PAT FileId(1) [12; 13)",
-            ReferenceKind::Other,
-            &["FileId(1) [38; 39) Other"],
+            "i BIND_PAT FileId(1) [12; 13) Other",
+            &["FileId(1) [38; 39) Other Read"],
         );
     }
 
@@ -317,9 +400,8 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "spam RECORD_FIELD_DEF FileId(1) [66; 79) [70; 74)",
-            ReferenceKind::Other,
-            &["FileId(1) [152; 156) Other"],
+            "spam RECORD_FIELD_DEF FileId(1) [66; 79) [70; 74) Other",
+            &["FileId(1) [152; 156) Other Read"],
         );
     }
 
@@ -334,7 +416,7 @@ mod tests {
         "#;
 
         let refs = get_all_refs(code);
-        check_result(refs, "f FN_DEF FileId(1) [88; 104) [91; 92)", ReferenceKind::Other, &[]);
+        check_result(refs, "f FN_DEF FileId(1) [88; 104) [91; 92) Other", &[]);
     }
 
     #[test]
@@ -349,7 +431,7 @@ mod tests {
         "#;
 
         let refs = get_all_refs(code);
-        check_result(refs, "B ENUM_VARIANT FileId(1) [83; 84) [83; 84)", ReferenceKind::Other, &[]);
+        check_result(refs, "B ENUM_VARIANT FileId(1) [83; 84) [83; 84) Other", &[]);
     }
 
     #[test]
@@ -390,8 +472,7 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(2) [16; 50) [27; 30)",
-            ReferenceKind::Other,
+            "Foo STRUCT_DEF FileId(2) [16; 50) [27; 30) Other",
             &["FileId(1) [52; 55) StructLiteral", "FileId(3) [77; 80) StructLiteral"],
         );
     }
@@ -421,8 +502,7 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "foo SOURCE_FILE FileId(2) [0; 35)",
-            ReferenceKind::Other,
+            "foo SOURCE_FILE FileId(2) [0; 35) Other",
             &["FileId(1) [13; 16) Other"],
         );
     }
@@ -451,8 +531,7 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(3) [0; 41) [18; 21)",
-            ReferenceKind::Other,
+            "Foo STRUCT_DEF FileId(3) [0; 41) [18; 21) Other",
             &["FileId(2) [20; 23) Other", "FileId(2) [46; 49) StructLiteral"],
         );
     }
@@ -480,8 +559,7 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "quux FN_DEF FileId(1) [18; 34) [25; 29)",
-            ReferenceKind::Other,
+            "quux FN_DEF FileId(1) [18; 34) [25; 29) Other",
             &["FileId(2) [16; 20) Other", "FileId(3) [16; 20) Other"],
         );
 
@@ -489,8 +567,7 @@ mod tests {
             analysis.find_all_refs(pos, Some(SearchScope::single_file(bar))).unwrap().unwrap();
         check_result(
             refs,
-            "quux FN_DEF FileId(1) [18; 34) [25; 29)",
-            ReferenceKind::Other,
+            "quux FN_DEF FileId(1) [18; 34) [25; 29) Other",
             &["FileId(3) [16; 20) Other"],
         );
     }
@@ -509,33 +586,99 @@ mod tests {
         let refs = get_all_refs(code);
         check_result(
             refs,
-            "m1 MACRO_CALL FileId(1) [9; 63) [46; 48)",
-            ReferenceKind::Other,
+            "m1 MACRO_CALL FileId(1) [9; 63) [46; 48) Other",
             &["FileId(1) [96; 98) Other", "FileId(1) [114; 116) Other"],
         );
     }
 
+    #[test]
+    fn test_basic_highlight_read_write() {
+        let code = r#"
+        fn foo() {
+            let i<|> = 0;
+            i = i + 1;
+        }"#;
+
+        let refs = get_all_refs(code);
+        check_result(
+            refs,
+            "i BIND_PAT FileId(1) [36; 37) Other Write",
+            &["FileId(1) [55; 56) Other Write", "FileId(1) [59; 60) Other Read"],
+        );
+    }
+
+    #[test]
+    fn test_basic_highlight_field_read_write() {
+        let code = r#"
+        struct S {
+            f: u32,
+        }
+
+        fn foo() {
+            let mut s = S{f: 0};
+            s.f<|> = 0;
+        }"#;
+
+        let refs = get_all_refs(code);
+        check_result(
+            refs,
+            "f RECORD_FIELD_DEF FileId(1) [32; 38) [32; 33) Other",
+            &["FileId(1) [96; 97) Other Read", "FileId(1) [117; 118) Other Write"],
+        );
+    }
+
+    #[test]
+    fn test_basic_highlight_decl_no_write() {
+        let code = r#"
+        fn foo() {
+            let i<|>;
+            i = 1;
+        }"#;
+
+        let refs = get_all_refs(code);
+        check_result(
+            refs,
+            "i BIND_PAT FileId(1) [36; 37) Other",
+            &["FileId(1) [51; 52) Other Write"],
+        );
+    }
+
     fn get_all_refs(text: &str) -> ReferenceSearchResult {
         let (analysis, position) = single_file_with_position(text);
         analysis.find_all_refs(position, None).unwrap().unwrap()
     }
 
-    fn check_result(
-        res: ReferenceSearchResult,
-        expected_decl: &str,
-        decl_kind: ReferenceKind,
-        expected_refs: &[&str],
-    ) {
+    fn check_result(res: ReferenceSearchResult, expected_decl: &str, expected_refs: &[&str]) {
         res.declaration().assert_match(expected_decl);
-        assert_eq!(res.declaration_kind, decl_kind);
-
         assert_eq!(res.references.len(), expected_refs.len());
         res.references().iter().enumerate().for_each(|(i, r)| r.assert_match(expected_refs[i]));
     }
 
+    impl Declaration {
+        fn debug_render(&self) -> String {
+            let mut s = format!("{} {:?}", self.nav.debug_render(), self.kind);
+            if let Some(access) = self.access {
+                s.push_str(&format!(" {:?}", access));
+            }
+            s
+        }
+
+        fn assert_match(&self, expected: &str) {
+            let actual = self.debug_render();
+            test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+        }
+    }
+
     impl Reference {
         fn debug_render(&self) -> String {
-            format!("{:?} {:?} {:?}", self.file_range.file_id, self.file_range.range, self.kind)
+            let mut s = format!(
+                "{:?} {:?} {:?}",
+                self.file_range.file_id, self.file_range.range, self.kind
+            );
+            if let Some(access) = self.access {
+                s.push_str(&format!(" {:?}", access));
+            }
+            s
         }
 
         fn assert_match(&self, expected: &str) {
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index c260b51c4..562699b7c 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -9,7 +9,7 @@ use lsp_types::{
 use ra_ide::{
     translate_offset_with_edit, CompletionItem, CompletionItemKind, FileId, FilePosition,
     FileRange, FileSystemEdit, Fold, FoldKind, InsertTextFormat, LineCol, LineIndex,
-    NavigationTarget, RangeInfo, Severity, SourceChange, SourceFileEdit,
+    NavigationTarget, RangeInfo, ReferenceAccess, Severity, SourceChange, SourceFileEdit,
 };
 use ra_syntax::{SyntaxKind, TextRange, TextUnit};
 use ra_text_edit::{AtomTextEdit, TextEdit};
@@ -53,6 +53,18 @@ impl Conv for SyntaxKind {
     }
 }
 
+impl Conv for ReferenceAccess {
+    type Output = ::lsp_types::DocumentHighlightKind;
+
+    fn conv(self) -> Self::Output {
+        use lsp_types::DocumentHighlightKind;
+        match self {
+            ReferenceAccess::Read => DocumentHighlightKind::Read,
+            ReferenceAccess::Write => DocumentHighlightKind::Write,
+        }
+    }
+}
+
 impl Conv for CompletionItemKind {
     type Output = ::lsp_types::CompletionItemKind;
 
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index a5b6f48af..a592f0a12 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -536,18 +536,32 @@ pub fn handle_references(
 
     let locations = if params.context.include_declaration {
         refs.into_iter()
-            .filter_map(|r| {
-                let line_index = world.analysis().file_line_index(r.file_range.file_id).ok()?;
-                to_location(r.file_range.file_id, r.file_range.range, &world, &line_index).ok()
+            .filter_map(|reference| {
+                let line_index =
+                    world.analysis().file_line_index(reference.file_range.file_id).ok()?;
+                to_location(
+                    reference.file_range.file_id,
+                    reference.file_range.range,
+                    &world,
+                    &line_index,
+                )
+                .ok()
             })
             .collect()
     } else {
         // Only iterate over the references if include_declaration was false
         refs.references()
             .iter()
-            .filter_map(|r| {
-                let line_index = world.analysis().file_line_index(r.file_range.file_id).ok()?;
-                to_location(r.file_range.file_id, r.file_range.range, &world, &line_index).ok()
+            .filter_map(|reference| {
+                let line_index =
+                    world.analysis().file_line_index(reference.file_range.file_id).ok()?;
+                to_location(
+                    reference.file_range.file_id,
+                    reference.file_range.range,
+                    &world,
+                    &line_index,
+                )
+                .ok()
             })
             .collect()
     };
@@ -836,10 +850,10 @@ pub fn handle_document_highlight(
 
     Ok(Some(
         refs.into_iter()
-            .filter(|r| r.file_range.file_id == file_id)
-            .map(|r| DocumentHighlight {
-                range: r.file_range.range.conv_with(&line_index),
-                kind: None,
+            .filter(|reference| reference.file_range.file_id == file_id)
+            .map(|reference| DocumentHighlight {
+                range: reference.file_range.range.conv_with(&line_index),
+                kind: reference.access.map(|it| it.conv()),
             })
             .collect(),
     ))
diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
index 23b6aa901..3dfecfe76 100644
--- a/crates/ra_syntax/src/ast/expr_extensions.rs
+++ b/crates/ra_syntax/src/ast/expr_extensions.rs
@@ -144,6 +144,7 @@ impl BinOp {
         }
     }
 }
+
 impl ast::BinExpr {
     pub fn op_details(&self) -> Option<(SyntaxToken, BinOp)> {
         self.syntax().children_with_tokens().filter_map(|it| it.into_token()).find_map(|c| {
diff --git a/editors/code/package.json b/editors/code/package.json
index 7d809a2d3..e7fc314f3 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -217,7 +217,10 @@
                     "description": "Trace requests to the ra_lsp_server"
                 },
                 "rust-analyzer.lruCapacity": {
-                    "type": "number",
+                    "type": [
+                        "number",
+                        "null"
+                    ],
                     "default": null,
                     "description": "Number of syntax trees rust-analyzer keeps in memory"
                 },