1 files changed, 99 insertions, 23 deletions

diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index ab45c364a..854b6cc6d 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -44,6 +44,7 @@ pub(crate) fn highlight(
     db: &RootDatabase,
     file_id: FileId,
     range_to_highlight: Option<TextRange>,
+    syntactic_name_ref_highlighting: bool,
 ) -> Vec<HighlightedRange> {
     let _p = profile("highlight");
     let sema = Semantics::new(db);
@@ -104,6 +105,7 @@ pub(crate) fn highlight(
                     if let Some((highlight, binding_hash)) = highlight_element(
                         &sema,
                         &mut bindings_shadow_count,
+                        syntactic_name_ref_highlighting,
                         name.syntax().clone().into(),
                     ) {
                         stack.add(HighlightedRange {
@@ -160,23 +162,25 @@ pub(crate) fn highlight(
             // Check if macro takes a format string and remember it for highlighting later.
             // The macros that accept a format string expand to a compiler builtin macros
             // `format_args` and `format_args_nl`.
-            if let Some(fmt_macro_call) = parent.parent().and_then(ast::MacroCall::cast) {
-                if let Some(name) =
-                    fmt_macro_call.path().and_then(|p| p.segment()).and_then(|s| s.name_ref())
-                {
-                    match name.text().as_str() {
-                        "format_args" | "format_args_nl" => {
-                            format_string = parent
-                                .children_with_tokens()
-                                .filter(|t| t.kind() != WHITESPACE)
-                                .nth(1)
-                                .filter(|e| {
-                                    ast::String::can_cast(e.kind())
-                                        || ast::RawString::can_cast(e.kind())
-                                })
-                        }
-                        _ => {}
+            if let Some(name) = parent
+                .parent()
+                .and_then(ast::MacroCall::cast)
+                .and_then(|mc| mc.path())
+                .and_then(|p| p.segment())
+                .and_then(|s| s.name_ref())
+            {
+                match name.text().as_str() {
+                    "format_args" | "format_args_nl" => {
+                        format_string = parent
+                            .children_with_tokens()
+                            .filter(|t| t.kind() != WHITESPACE)
+                            .nth(1)
+                            .filter(|e| {
+                                ast::String::can_cast(e.kind())
+                                    || ast::RawString::can_cast(e.kind())
+                            })
                     }
+                    _ => {}
                 }
             }
 
@@ -198,15 +202,18 @@ pub(crate) fn highlight(
 
         let is_format_string = format_string.as_ref() == Some(&element_to_highlight);
 
-        if let Some((highlight, binding_hash)) =
-            highlight_element(&sema, &mut bindings_shadow_count, element_to_highlight.clone())
-        {
+        if let Some((highlight, binding_hash)) = highlight_element(
+            &sema,
+            &mut bindings_shadow_count,
+            syntactic_name_ref_highlighting,
+            element_to_highlight.clone(),
+        ) {
             stack.add(HighlightedRange { range, highlight, binding_hash });
             if let Some(string) =
                 element_to_highlight.as_token().cloned().and_then(ast::String::cast)
             {
-                stack.push();
                 if is_format_string {
+                    stack.push();
                     string.lex_format_specifier(|piece_range, kind| {
                         if let Some(highlight) = highlight_format_specifier(kind) {
                             stack.add(HighlightedRange {
@@ -216,13 +223,27 @@ pub(crate) fn highlight(
                             });
                         }
                     });
+                    stack.pop();
+                }
+                // Highlight escape sequences
+                if let Some(char_ranges) = string.char_ranges() {
+                    stack.push();
+                    for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
+                        if string.text()[piece_range.start().into()..].starts_with('\\') {
+                            stack.add(HighlightedRange {
+                                range: piece_range + range.start(),
+                                highlight: HighlightTag::EscapeSequence.into(),
+                                binding_hash: None,
+                            });
+                        }
+                    }
+                    stack.pop_and_inject(false);
                 }
-                stack.pop();
             } else if let Some(string) =
                 element_to_highlight.as_token().cloned().and_then(ast::RawString::cast)
             {
-                stack.push();
                 if is_format_string {
+                    stack.push();
                     string.lex_format_specifier(|piece_range, kind| {
                         if let Some(highlight) = highlight_format_specifier(kind) {
                             stack.add(HighlightedRange {
@@ -232,8 +253,8 @@ pub(crate) fn highlight(
                             });
                         }
                     });
+                    stack.pop();
                 }
-                stack.pop();
             }
         }
     }
@@ -408,6 +429,7 @@ fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
 fn highlight_element(
     sema: &Semantics<RootDatabase>,
     bindings_shadow_count: &mut FxHashMap<Name, u32>,
+    syntactic_name_ref_highlighting: bool,
     element: SyntaxElement,
 ) -> Option<(Highlight, Option<u64>)> {
     let db = sema.db;
@@ -461,6 +483,7 @@ fn highlight_element(
                     }
                     NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
                 },
+                None if syntactic_name_ref_highlighting => highlight_name_ref_by_syntax(name_ref),
                 None => HighlightTag::UnresolvedReference.into(),
             }
         }
@@ -493,6 +516,9 @@ fn highlight_element(
             h |= HighlightModifier::Unsafe;
             h
         }
+        T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
+            Highlight::new(HighlightTag::Macro)
+        }
 
         k if k.is_keyword() => {
             let h = Highlight::new(HighlightTag::Keyword);
@@ -609,3 +635,53 @@ fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
 
     tag.into()
 }
+
+fn highlight_name_ref_by_syntax(name: ast::NameRef) -> Highlight {
+    let default = HighlightTag::UnresolvedReference;
+
+    let parent = match name.syntax().parent() {
+        Some(it) => it,
+        _ => return default.into(),
+    };
+
+    let tag = match parent.kind() {
+        METHOD_CALL_EXPR => HighlightTag::Function,
+        FIELD_EXPR => HighlightTag::Field,
+        PATH_SEGMENT => {
+            let path = match parent.parent().and_then(ast::Path::cast) {
+                Some(it) => it,
+                _ => return default.into(),
+            };
+            let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) {
+                Some(it) => it,
+                _ => {
+                    // within path, decide whether it is module or adt by checking for uppercase name
+                    return if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                        HighlightTag::Struct
+                    } else {
+                        HighlightTag::Module
+                    }
+                    .into();
+                }
+            };
+            let parent = match expr.syntax().parent() {
+                Some(it) => it,
+                None => return default.into(),
+            };
+
+            match parent.kind() {
+                CALL_EXPR => HighlightTag::Function,
+                _ => {
+                    if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                        HighlightTag::Struct
+                    } else {
+                        HighlightTag::Constant
+                    }
+                }
+            }
+        }
+        _ => default,
+    };
+
+    tag.into()
+}