nixd: publish variable lookup diagnostics (#383)

nixd/tools/nixd/src/Support.cpp

@@ -6,6 +6,7 @@
 #include "nixf/Basic/Diagnostic.h"
 #include "nixf/Bytecode/Write.h"
 #include "nixf/Parse/Parser.h"
+#include "nixf/Sema/VariableLookup.h"
 
 #include <boost/asio/post.hpp>
 
@@ -38,14 +39,19 @@ void Controller::actOnDocumentAdd(PathRef File,
     std::vector<nixf::Diagnostic> Diagnostics;
     std::shared_ptr<nixf::Node> AST =
         nixf::parse(*Draft->Contents, Diagnostics);
-    publishDiagnostics(File, Version, Diagnostics);
 
     if (!AST) {
       std::lock_guard G(TUsLock);
+      publishDiagnostics(File, Version, Diagnostics);
       TUs[File] = NixTU(std::move(Diagnostics), std::move(AST), std::nullopt);
       return;
     }
 
+    nixf::VariableLookupAnalysis VLA(Diagnostics);
+    VLA.runOnAST(*AST);
+
+    publishDiagnostics(File, Version, Diagnostics);
+
     // Serialize the AST into shared memory. Prepare for evaluation.
     std::stringstream OS;
     nixf::writeBytecode(OS, AST.get());

nixd/tools/nixd/test/diagnostic-liveness.md

@@ -0,0 +1,63 @@
+# RUN: nixd --lit-test < %s | FileCheck %s
+
+<-- initialize(0)
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":0,
+   "method":"initialize",
+   "params":{
+      "processId":123,
+      "rootPath":"",
+      "capabilities":{
+      },
+      "trace":"off"
+   }
+}
+```
+
+
+<-- textDocument/didOpen
+
+```json
+{
+   "jsonrpc":"2.0",
+   "method":"textDocument/didOpen",
+   "params":{
+      "textDocument":{
+         "uri":"file:///basic.nix",
+         "languageId":"nix",
+         "version":1,
+         "text":"x: y: x + 1"
+      }
+   }
+}
+```
+
+```
+     CHECK: "diagnostics": [
+CHECK-NEXT:   {
+CHECK-NEXT:     "code": "sema-def-not-used",
+CHECK-NEXT:     "message": "definition `y` is not used",
+CHECK-NEXT:     "range": {
+CHECK-NEXT:       "end": {
+CHECK-NEXT:         "character": 4,
+CHECK-NEXT:         "line": 0
+CHECK-NEXT:       },
+CHECK-NEXT:       "start": {
+CHECK-NEXT:         "character": 3,
+CHECK-NEXT:         "line": 0
+CHECK-NEXT:       }
+CHECK-NEXT:     },
+CHECK-NEXT:     "relatedInformation": [],
+CHECK-NEXT:     "severity": 2,
+CHECK-NEXT:     "source": "nixf",
+CHECK-NEXT:     "tags": [
+CHECK-NEXT:       1
+CHECK-NEXT:     ]
+CHECK-NEXT:   }
+CHECK-NEXT: ],
+CHECK-NEXT: "uri": "file:///basic.nix",
+CHECK-NEXT: "version": 1
+```