nixd: diagnostic control system (#505)

nixd/docs/configuration.md

@@ -145,12 +145,34 @@ nvim_lsp.nixd.setup({
     "home-manager": {
       "expr": "(builtins.getFlake \"/home/lyc/flakes\").homeConfigurations.\"lyc@adrastea\".options"
     }
+  },
+  // Control the diagnostic system
+  "diagnostic": {
+    "suppress": [
+      "sema-escaping-with"
+    ]
   }
 }
 ```
 
 ### Fields explanation
 
+#### Diagnostic Control ("diagnostic")
+
+Some users might feel confident in their understanding of the language and
+prefer to suppress diagnostics altogether. This can be achieved by utilizing the diagnostic field.
+
+```jsonc
+{
+  "diagnostic": {
+    // A list of diagnostic short names
+    "suppress": [
+      "sema-escaping-with"
+    ]
+  }
+}
+```
+
 #### Format ("formating")
 
 To configure which command will be used for formatting, you can change the "formatting" section.

nixd/include/nixd/Controller/Configuration.h

@@ -27,8 +27,15 @@ struct Configuration {
     /// \brief Expression to eval. Treat it as "import <nixpkgs> { }"
     std::string expr;
   } nixpkgs;
+
+  struct Diagnostic {
+    std::vector<std::string> suppress;
+  } diagnostic;
 };
 
+bool fromJSON(const llvm::json::Value &Params, Configuration::Diagnostic &R,
+              llvm::json::Path P);
+
 bool fromJSON(const llvm::json::Value &Params, Configuration::Formatting &R,
               llvm::json::Path P);
 

nixd/include/nixd/Controller/Controller.h

@@ -8,9 +8,12 @@
 #include "lspserver/LSPServer.h"
 #include "lspserver/Protocol.h"
 #include "nixd/Eval/AttrSetClient.h"
+#include "nixf/Basic/Diagnostic.h"
 
 #include <boost/asio/thread_pool.hpp>
 
+#include <set>
+
 namespace nixd {
 
 class Controller : public lspserver::LSPServer {
@@ -199,6 +202,17 @@ class Controller : public lspserver::LSPServer {
       const lspserver::DocumentLinkParams &Params,
       lspserver::Callback<std::vector<lspserver::DocumentLink>> Reply);
 
+  std::set<nixf::Diagnostic::DiagnosticKind>
+      SuppressedDiagnostics; // GUARDED_BY(SuppressedDiagnosticsLock)
+
+  std::mutex SuppressedDiagnosticsLock;
+
+  /// Update the suppressing set. There might be some invalid names, should be
+  /// logged then.
+  void updateSuppressed(const std::vector<std::string> &Sup);
+
+  /// Determine whether or not this diagnostic is suppressed.
+  bool isSuppressed(nixf::Diagnostic::DiagnosticKind Kind);
   void publishDiagnostics(lspserver::PathRef File,
                           std::optional<int64_t> Version,
                           const std::vector<nixf::Diagnostic> &Diagnostics);

nixd/lib/Controller/Configuration.cpp

@@ -8,6 +8,12 @@ using namespace lspserver;
 using llvm::json::ObjectMapper;
 using llvm::json::Value;
 
+bool nixd::fromJSON(const Value &Params, Configuration::Diagnostic &R,
+                    llvm::json::Path P) {
+  ObjectMapper O(Params, P);
+  return O && O.mapOptional("suppress", R.suppress);
+}
+
 bool nixd::fromJSON(const Value &Params, Configuration::Formatting &R,
                     llvm::json::Path P) {
   // If it is a single string, treat it as a single vector
@@ -37,6 +43,7 @@ bool nixd::fromJSON(const Value &Params, Configuration &R, llvm::json::Path P) {
          && O.mapOptional("formatting", R.formatting) //
          && O.mapOptional("options", R.options)       //
          && O.mapOptional("nixpkgs", R.nixpkgs)       //
+         && O.mapOptional("diagnostic", R.diagnostic) //
       ;
 }
 
@@ -70,6 +77,15 @@ void Controller::updateConfig(Configuration NewConfig) {
       evalExprWithProgress(*Client->client(), Opt.expr, Name);
     }
   }
+
+  // Update the diagnostic part.
+  updateSuppressed(Config.diagnostic.suppress);
+
+  // After all, notify all AST modules the diagnostic set has been updated.
+  std::lock_guard TUsGuard(TUsLock);
+  for (const auto &[File, TU] : TUs) {
+    publishDiagnostics(File, std::nullopt, TU->diagnostics());
+  }
 }
 
 void Controller::fetchConfig() {

nixd/lib/Controller/Diagnostics.cpp

@@ -7,17 +7,65 @@
 
 #include "nixd/Controller/Controller.h"
 
-namespace nixd {
+#include <nixf/Basic/Diagnostic.h>
 
+#include <mutex>
+#include <optional>
+
+using namespace nixd;
 using namespace llvm::json;
 using namespace lspserver;
 
+void Controller::updateSuppressed(const std::vector<std::string> &Sup) {
+  // For convenience, alias it to a short name
+  using DK = nixf::Diagnostic::DiagnosticKind;
+  // Acquire the lock because the set needs to be written.
+  std::lock_guard _(SuppressedDiagnosticsLock);
+  // Clear the set, just construct a new one.
+  SuppressedDiagnostics.clear();
+
+  // Hashed string used for lookup names
+  static std::unordered_map<std::string, nixf::Diagnostic::DiagnosticKind>
+      DKMap;
+
+  // Insert declared sname in nixf, diagnostics.
+  struct AddDK {
+    AddDK(const std::string &Name, DK Kind) { DKMap.insert({Name, Kind}); }
+  };
+#define DIAG(SNAME, CNAME, LEVEL, STR)                                         \
+  static AddDK DK_Add_##CNAME(SNAME, DK::DK_##CNAME);
+#include <nixf/Basic/DiagnosticKinds.inc>
+#undef DIAG
+
+  // For each element, see if the name matches some declared name.
+  // If so, insert the set.
+  for (const auto &Name : Sup) {
+    if (auto It = DKMap.find(Name); It != DKMap.end()) {
+      SuppressedDiagnostics.insert(It->second);
+    } else {
+      // The name is not listed in knwon names. Log error here
+      lspserver::elog("diagnostic suppressing sname {0} is unknown", Name);
+    }
+  }
+}
+
+bool Controller::isSuppressed(nixf::Diagnostic::DiagnosticKind Kind) {
+  std::lock_guard _(SuppressedDiagnosticsLock);
+  return SuppressedDiagnostics.contains(Kind);
+}
+
 void Controller::publishDiagnostics(
     PathRef File, std::optional<int64_t> Version,
     const std::vector<nixf::Diagnostic> &Diagnostics) {
   std::vector<Diagnostic> LSPDiags;
   LSPDiags.reserve(Diagnostics.size());
   for (const nixf::Diagnostic &D : Diagnostics) {
+    // Before actually doing anything,
+    // let's check if the diagnostic is suppressed.
+    // If suppressed, just skip it.
+    if (isSuppressed(D.kind()))
+      continue;
+
     // Format the message.
     std::string Message = D.format();
 
@@ -85,5 +133,3 @@ void Controller::publishDiagnostics(
       .version = Version,
   });
 }
-
-} // namespace nixd