Language server fixes and improvements (#2304)

* Language server: Inlay hints.

* Signature help for base exprs that is not a declref.

* Fix checking of jvp operator.

* Fix.

* Add clang-format based auto formatting.

* Fix clang error.

* Fix clang-format discovery logic.

* Fine tune auto formatting and completion experience.

* Update macos workflow.

* Fixes to configurations.

* Fix parser recovery to trigger completion for index exprs.

* Typo fix.

Co-authored-by: Yong He <yhe@nvidia.com>

3 files changed, 361 insertions, 6 deletions

diff --git a/source/compiler-core/slang-language-server-protocol.cpp b/source/compiler-core/slang-language-server-protocol.cpp
index 51799f05e..d2950b164 100644
--- a/source/compiler-core/slang-language-server-protocol.cpp
+++ b/source/compiler-core/slang-language-server-protocol.cpp
@@ -25,6 +25,27 @@ static const StructRttiInfo _makeWorkDoneProgressParamsRtti()
 }
 const StructRttiInfo WorkDoneProgressParams::g_rttiInfo = _makeWorkDoneProgressParamsRtti();
 
+static const StructRttiInfo _makeInlayHintOptionsRtti()
+{
+    InlayHintOptions obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::InlayHintOptions", nullptr);
+    builder.addField("resolveProvider", &obj.resolveProvider);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo InlayHintOptions::g_rttiInfo = _makeInlayHintOptionsRtti();
+
+static const StructRttiInfo _makeDocumentOnTypeFormattingOptionsRtti()
+{
+    DocumentOnTypeFormattingOptions obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::DocumentOnTypeFormattingOptions", nullptr);
+    builder.addField("firstTriggerCharacter", &obj.firstTriggerCharacter);
+    builder.addField("moreTriggerCharacter", &obj.moreTriggerCharacter);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo DocumentOnTypeFormattingOptions::g_rttiInfo = _makeDocumentOnTypeFormattingOptionsRtti();
+
 static const StructRttiInfo _makeCompletionOptionsRtti()
 {
     CompletionOptions obj;
@@ -211,6 +232,10 @@ static const StructRttiInfo _makeServerCapabilitiesRtti()
     builder.addField("textDocumentSync", &obj.textDocumentSync);
     builder.addField("workspace", &obj.workspace);
     builder.addField("hoverProvider", &obj.hoverProvider);
+    builder.addField("inlayHintProvider", &obj.inlayHintProvider);
+    builder.addField("documentOnTypeFormattingProvider", &obj.documentOnTypeFormattingProvider);
+    builder.addField("documentFormattingProvider", &obj.documentFormattingProvider);
+    builder.addField("documentRangeFormattingProvider", &obj.documentRangeFormattingProvider);
     builder.addField("definitionProvider", &obj.definitionProvider);
     builder.addField("completionProvider", &obj.completionProvider);
     builder.addField("semanticTokensProvider", &obj.semanticTokensProvider);
@@ -382,6 +407,17 @@ static const StructRttiInfo _makeHoverRtti()
 }
 const StructRttiInfo Hover::g_rttiInfo = _makeHoverRtti();
 
+static const StructRttiInfo _makeCompletionContextRtti()
+{
+    CompletionContext obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::CompletionContext", nullptr);
+    builder.addField("triggerKind", &obj.triggerKind);
+    builder.addField("triggerCharacter", &obj.triggerCharacter, StructRttiInfo::Flag::Optional);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo CompletionContext::g_rttiInfo = _makeCompletionContextRtti();
+
 static const StructRttiInfo _makeDefinitionParamsRtti()
 {
     DefinitionParams obj;
@@ -401,6 +437,7 @@ static const StructRttiInfo _makeCompletionParamsRtti()
     StructRttiBuilder builder(&obj, "LanguageServerProtocol::CompletionParams", &WorkDoneProgressParams::g_rttiInfo);
     builder.addField("textDocument", &obj.textDocument);
     builder.addField("position", &obj.position);
+    builder.addField("context", &obj.context, StructRttiInfo::Flag::Optional);
     builder.ignoreUnknownFields();
     return builder.make();
 }
@@ -604,6 +641,87 @@ static const StructRttiInfo _makeDocumentSymbolRtti()
 }
 const StructRttiInfo DocumentSymbol::g_rttiInfo = _makeDocumentSymbolRtti();
 
+static const StructRttiInfo _makeTextEditRtti()
+{
+    TextEdit obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::TextEdit", nullptr);
+    builder.addField("range", &obj.range);
+    builder.addField("newText", &obj.newText);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo TextEdit::g_rttiInfo = _makeTextEditRtti();
+
+static const StructRttiInfo _makeInlayHintParamsRtti()
+{
+    InlayHintParams obj;
+    StructRttiBuilder builder(
+        &obj, "LanguageServerProtocol::InlayHintParams", nullptr);
+    builder.addField("range", &obj.range);
+    builder.addField("textDocument", &obj.textDocument);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo InlayHintParams::g_rttiInfo = _makeInlayHintParamsRtti();
+const UnownedStringSlice InlayHintParams::methodName =
+    UnownedStringSlice::fromLiteral("textDocument/inlayHint");
+
+static const StructRttiInfo _makeInlayHintRtti()
+{
+    InlayHint obj;
+    StructRttiBuilder builder(
+        &obj, "LanguageServerProtocol::InlayHint", nullptr);
+    builder.addField("position", &obj.position);
+    builder.addField("label", &obj.label);
+    builder.addField("kind", &obj.kind);
+    builder.addField("paddingLeft", &obj.paddingLeft);
+    builder.addField("paddingRight", &obj.paddingRight);
+    builder.addField("textEdits", &obj.textEdits);
+
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo InlayHint::g_rttiInfo = _makeInlayHintRtti();
+
+static const StructRttiInfo _makeDocumentFormattingParamsRtti()
+{
+    DocumentFormattingParams obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::DocumentFormattingParams", nullptr);
+    builder.addField("textDocument", &obj.textDocument);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo DocumentFormattingParams::g_rttiInfo = _makeDocumentFormattingParamsRtti();
+const UnownedStringSlice DocumentFormattingParams::methodName =
+    UnownedStringSlice::fromLiteral("textDocument/formatting");
+
+static const StructRttiInfo _makeDocumentRangeFormattingParamsRtti()
+{
+    DocumentRangeFormattingParams obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::DocumentRangeFormattingParams", nullptr);
+    builder.addField("textDocument", &obj.textDocument);
+    builder.addField("range", &obj.range);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo DocumentRangeFormattingParams::g_rttiInfo = _makeDocumentRangeFormattingParamsRtti();
+const UnownedStringSlice DocumentRangeFormattingParams::methodName =
+    UnownedStringSlice::fromLiteral("textDocument/rangeFormatting");
+
+static const StructRttiInfo _makeDocumentOnTypeFormattingParamsRtti()
+{
+    DocumentOnTypeFormattingParams obj;
+    StructRttiBuilder builder(&obj, "LanguageServerProtocol::DocumentOnTypeFormattingParams", nullptr);
+    builder.addField("textDocument", &obj.textDocument);
+    builder.addField("position", &obj.position);
+    builder.addField("ch", &obj.ch);
+    builder.ignoreUnknownFields();
+    return builder.make();
+}
+const StructRttiInfo DocumentOnTypeFormattingParams::g_rttiInfo = _makeDocumentOnTypeFormattingParamsRtti();
+const UnownedStringSlice DocumentOnTypeFormattingParams::methodName =
+    UnownedStringSlice::fromLiteral("textDocument/onTypeFormatting");
+
 } // namespace LanguageServerProtocol
 
 }
diff --git a/source/compiler-core/slang-language-server-protocol.h b/source/compiler-core/slang-language-server-protocol.h
index 7d9d8d5cb..fbc79acca 100644
--- a/source/compiler-core/slang-language-server-protocol.h
+++ b/source/compiler-core/slang-language-server-protocol.h
@@ -232,6 +232,37 @@ struct WorkspaceCapabilities
     static const StructRttiInfo g_rttiInfo;
 };
 
+/**
+ * Inlay hint options used during static registration.
+ *
+ * @since 3.17.0
+ */
+struct InlayHintOptions
+{
+    /**
+     * The server provides support to resolve additional
+     * information for an inlay hint item.
+     */
+    bool resolveProvider = false;
+    static const StructRttiInfo g_rttiInfo;
+
+};
+
+struct DocumentOnTypeFormattingOptions
+{
+    /**
+     * A character on which formatting should be triggered, like `{`.
+     */
+    String firstTriggerCharacter;
+
+    /**
+     * More trigger characters.
+     */
+    List<String> moreTriggerCharacter;
+
+    static const StructRttiInfo g_rttiInfo;
+};
+
 struct ServerCapabilities
 {
     String positionEncoding;
@@ -239,6 +270,10 @@ struct ServerCapabilities
     bool hoverProvider = false;
     bool definitionProvider = false;
     bool documentSymbolProvider = false;
+    bool documentFormattingProvider = false;
+    bool documentRangeFormattingProvider = false;
+    DocumentOnTypeFormattingOptions documentOnTypeFormattingProvider;
+    InlayHintOptions inlayHintProvider;
     CompletionOptions completionProvider;
     SemanticTokensOptions semanticTokensProvider;
     SignatureHelpOptions signatureHelpProvider;
@@ -336,7 +371,7 @@ struct Diagnostic
      * The diagnostic's severity. Can be omitted. If omitted it is up to the
      * client to interpret diagnostics as error, warning, info or hint.
      */
-    DiagnosticSeverity severity;
+    DiagnosticSeverity severity = 1;
 
     /**
      * The diagnostic's code, which might appear in the user interface.
@@ -452,10 +487,48 @@ struct Hover
     static const StructRttiInfo g_rttiInfo;
 };
 
+typedef int CompletionTriggerKind;
+const CompletionTriggerKind kCompletionTriggerKindInvoked = 1;
+
+/**
+ * Completion was triggered by a trigger character specified by
+ * the `triggerCharacters` properties of the
+ * `CompletionRegistrationOptions`.
+ */
+const CompletionTriggerKind kCompletionTriggerKindTriggerCharacter = 2;
+
+/**
+ * Completion was re-triggered as the current completion list is incomplete.
+ */
+const CompletionTriggerKind kCompletionTriggerKindTriggerForIncompleteCompletions = 3;
+
+/**
+ * Contains additional information about the context in which a completion
+ * request is triggered.
+ */
+struct CompletionContext
+{
+    /**
+     * How the completion was triggered.
+     */
+    CompletionTriggerKind triggerKind = 1;
+
+    /**
+     * The trigger character (a single character) that has trigger code
+     * complete. Is undefined if
+     * `triggerKind !== CompletionTriggerKind.TriggerCharacter`
+     */
+    String triggerCharacter;
+
+    static const StructRttiInfo g_rttiInfo;
+};
+
 struct CompletionParams
     : WorkDoneProgressParams
     , TextDocumentPositionParams
 {
+    CompletionContext context;
+
     static const StructRttiInfo g_rttiInfo;
     static const UnownedStringSlice methodName;
 };
@@ -786,8 +859,8 @@ const int kSymbolKindTypeParameter = 26;
  * have two ranges: one that encloses its definition and one that points to its
  * most interesting range, e.g. the range of an identifier.
  */
-struct DocumentSymbol {
-
+struct DocumentSymbol
+{
     /**
      * The name of this symbol. Will be displayed in the user interface and
      * therefore must not be an empty string or a string only consisting of
@@ -803,7 +876,7 @@ struct DocumentSymbol {
     /**
      * The kind of this symbol.
      */
-    SymbolKind kind;
+    SymbolKind kind = 0;
 
     /**
      * The range enclosing this symbol not including leading/trailing whitespace
@@ -827,5 +900,166 @@ struct DocumentSymbol {
     static const StructRttiInfo g_rttiInfo;
 };
 
+/**
+ * A parameter literal used in inlay hint requests.
+ *
+ * @since 3.17.0
+ */
+struct InlayHintParams
+{
+    /**
+     * The text document.
+     */
+    TextDocumentIdentifier textDocument;
+
+    /**
+     * The visible document range for which inlay hints should be computed.
+     */
+    Range range;
+
+    static const StructRttiInfo g_rttiInfo;
+    static const UnownedStringSlice methodName;
+};
+
+struct TextEdit
+{
+    /**
+     * The range of the text document to be manipulated. To insert
+     * text into a document create a range where start === end.
+     */
+    Range range;
+
+    /**
+     * The string to be inserted. For delete operations use an
+     * empty string.
+     */
+    String newText;
+
+    static const StructRttiInfo g_rttiInfo;
+
+};
+
+typedef int InlayHintKind;
+const int kInlayHintKindType = 1;
+const int kInlayHintKindParameter = 2;
+
+/**
+ * Inlay hint information.
+ *
+ * @since 3.17.0
+ */
+struct InlayHint
+{
+    /**
+     * The position of this hint.
+     */
+    Position position;
+
+    /**
+     * The label of this hint. A human readable string or an array of
+     * InlayHintLabelPart label parts.
+     *
+     * *Note* that neither the string nor the label part can be empty.
+     */
+    String label;
+
+    /**
+     * The kind of this hint. Can be omitted in which case the client
+     * should fall back to a reasonable default.
+     */
+    InlayHintKind kind = 1;
+
+    List<TextEdit> textEdits;
+
+    /**
+     * Render padding before the hint.
+     *
+     * Note: Padding should use the editor's background color, not the
+     * background color of the hint itself. That means padding can be used
+     * to visually align/separate an inlay hint.
+     */
+    bool paddingLeft = false;
+
+    /**
+     * Render padding after the hint.
+     *
+     * Note: Padding should use the editor's background color, not the
+     * background color of the hint itself. That means padding can be used
+     * to visually align/separate an inlay hint.
+     */
+    bool paddingRight = false;
+
+    static const StructRttiInfo g_rttiInfo;
+
+};
+
+struct DocumentOnTypeFormattingParams
+{
+    /**
+     * The document to format.
+     */
+    TextDocumentIdentifier textDocument;
+
+    /**
+     * The position around which the on type formatting should happen.
+     * This is not necessarily the exact position where the character denoted
+     * by the property `ch` got typed.
+     */
+    Position position;
+
+    /**
+     * The character that has been typed that triggered the formatting
+     * on type request. That is not necessarily the last character that
+     * got inserted into the document since the client could auto insert
+     * characters as well (e.g. like automatic brace completion).
+     */
+    String ch;
+
+    /**
+     * The formatting options.
+     */
+    //FormattingOptions options;
+
+    static const StructRttiInfo g_rttiInfo;
+    static const UnownedStringSlice methodName;
+};
+
+struct DocumentRangeFormattingParams
+{
+    /**
+     * The document to format.
+     */
+    TextDocumentIdentifier textDocument;
+
+    /**
+     * The range to format
+     */
+    Range range;
+
+    /**
+     * The format options
+     */
+    //FormattingOptions options;
+
+    static const StructRttiInfo g_rttiInfo;
+    static const UnownedStringSlice methodName;
+};
+
+struct DocumentFormattingParams
+{
+    /**
+     * The document to format.
+     */
+    TextDocumentIdentifier textDocument;
+
+    /**
+     * The format options
+     */
+    //FormattingOptions options;
+
+    static const StructRttiInfo g_rttiInfo;
+    static const UnownedStringSlice methodName;
+};
+
 } // namespace LanguageServerProtocol
 } // namespace Slang
diff --git a/source/compiler-core/slang-lexer.cpp b/source/compiler-core/slang-lexer.cpp
index fd0255575..4a6d7d392 100644
--- a/source/compiler-core/slang-lexer.cpp
+++ b/source/compiler-core/slang-lexer.cpp
@@ -1340,9 +1340,12 @@ namespace Slang
                 }
             }
 
-            if (tokenType == TokenType::Identifier || tokenType == TokenType::CompletionRequest)
+            if (m_namePool)
             {
-                token.setName(m_namePool->getName(token.getContent()));
+                if (tokenType == TokenType::Identifier || tokenType == TokenType::CompletionRequest)
+                {
+                    token.setName(m_namePool->getName(token.getContent()));
+                }
             }
 
             return token;