From da545f1139f15bd4878a3b98a4d3de85758838d0 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Thu, 31 May 2018 16:28:47 -0700
Subject: [PATCH] $ccls/vars: differentiate local/field/parameter

---
 src/messages/ccls_vars.cc               | 24 ++++++++++++-------
 src/messages/text_document_code_lens.cc |  2 +-
 src/query_utils.cc                      | 31 +++++++++++++++++++++++--
 src/query_utils.h                       |  2 +-
 4 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/src/messages/ccls_vars.cc b/src/messages/ccls_vars.cc
index 95d8ff91..70616845 100644
--- a/src/messages/ccls_vars.cc
+++ b/src/messages/ccls_vars.cc
@@ -8,9 +8,17 @@ MethodType kMethodType = "$ccls/vars";
 
 struct In_CclsVars : public RequestInMessage {
   MethodType GetMethodType() const override { return kMethodType; }
-
-  lsTextDocumentPositionParams params;
+  struct Params : lsTextDocumentPositionParams {
+    // 1: field
+    // 2: local
+    // 4: parameter
+    unsigned kind = ~0u;
+  } params;
 };
+MAKE_REFLECT_STRUCT(In_CclsVars::Params,
+                    textDocument,
+                    position,
+                    kind);
 MAKE_REFLECT_STRUCT(In_CclsVars, id, params);
 REGISTER_IN_MESSAGE(In_CclsVars);
 
@@ -18,11 +26,11 @@ struct Handler_CclsVars : BaseMessageHandler<In_CclsVars> {
   MethodType GetMethodType() const override { return kMethodType; }
 
   void Run(In_CclsVars* request) override {
+    auto& params = request->params;
     QueryFile* file;
     if (!FindFileOrFail(db, project, request->id,
-                        request->params.textDocument.uri.GetPath(), &file)) {
+                        params.textDocument.uri.GetPath(), &file))
       return;
-    }
 
     WorkingFile* working_file =
         working_files->GetFileByFilename(file->def->path);
@@ -30,7 +38,7 @@ struct Handler_CclsVars : BaseMessageHandler<In_CclsVars> {
     Out_LocationList out;
     out.id = request->id;
     for (SymbolRef sym :
-         FindSymbolsAtLocation(working_file, file, request->params.position)) {
+         FindSymbolsAtLocation(working_file, file, params.position)) {
       Usr usr = sym.usr;
       switch (sym.kind) {
         default:
@@ -43,9 +51,9 @@ struct Handler_CclsVars : BaseMessageHandler<In_CclsVars> {
           [[fallthrough]];
         }
         case SymbolKind::Type:
-          out.result =
-              GetLsLocationExs(db, working_files,
-                               GetVarDeclarations(db, db->Type(usr).instances));
+          out.result = GetLsLocationExs(
+              db, working_files,
+              GetVarDeclarations(db, db->Type(usr).instances, params.kind));
           break;
       }
     }
diff --git a/src/messages/text_document_code_lens.cc b/src/messages/text_document_code_lens.cc
index 0691ac30..bd6704fd 100644
--- a/src/messages/text_document_code_lens.cc
+++ b/src/messages/text_document_code_lens.cc
@@ -121,7 +121,7 @@ struct Handler_TextDocumentCodeLens
                       GetTypeDeclarations(db, type.derived),
                       false /*force_display*/);
           AddCodeLens("var", "vars", &common, OffsetStartColumn(use, 2),
-                      GetVarDeclarations(db, type.instances),
+                      GetVarDeclarations(db, type.instances, true),
                       false /*force_display*/);
           break;
         }
diff --git a/src/query_utils.cc b/src/query_utils.cc
index 6ffdb4af..0ced17ba 100644
--- a/src/query_utils.cc
+++ b/src/query_utils.cc
@@ -59,8 +59,35 @@ std::vector<Use> GetFuncDeclarations(DB* db, const std::vector<Usr>& usrs) {
 std::vector<Use> GetTypeDeclarations(DB* db, const std::vector<Usr>& usrs) {
   return GetDeclarations(db->type_usr, db->types, usrs);
 }
-std::vector<Use> GetVarDeclarations(DB* db, const std::vector<Usr>& usrs) {
-  return GetDeclarations(db->var_usr, db->vars, usrs);
+std::vector<Use> GetVarDeclarations(DB* db,
+                                    const std::vector<Usr>& usrs,
+                                    unsigned kind) {
+  std::vector<Use> ret;
+  ret.reserve(usrs.size());
+  for (Usr usr : usrs) {
+    QueryVar& var = db->Var(usr);
+    bool has_def = false;
+    for (auto& def : var.def)
+      if (def.spell) {
+        has_def = true;
+        // See messages/ccls_vars.cc
+        if (def.kind == lsSymbolKind::Field) {
+          if (!(kind & 1))
+            break;
+        } else if (def.kind == lsSymbolKind::Variable) {
+          if (!(kind & 2))
+            break;
+        } else if (def.kind == lsSymbolKind::Parameter) {
+          if (!(kind & 4))
+            break;
+        }
+        ret.push_back(*def.spell);
+        break;
+      }
+    if (!has_def && var.declarations.size())
+      ret.push_back(var.declarations[0]);
+  }
+  return ret;
 }
 
 std::vector<Use> GetNonDefDeclarations(DB* db, SymbolIdx sym) {
diff --git a/src/query_utils.h b/src/query_utils.h
index 239738cb..52397000 100644
--- a/src/query_utils.h
+++ b/src/query_utils.h
@@ -12,7 +12,7 @@ Maybe<Use> GetDefinitionExtent(DB* db, SymbolIdx sym);
 // for each id.
 std::vector<Use> GetFuncDeclarations(DB*, const std::vector<Usr>&);
 std::vector<Use> GetTypeDeclarations(DB*, const std::vector<Usr>&);
-std::vector<Use> GetVarDeclarations(DB*, const std::vector<Usr>&);
+std::vector<Use> GetVarDeclarations(DB*, const std::vector<Usr>&, unsigned);
 
 // Get non-defining declarations.
 std::vector<Use> GetNonDefDeclarations(DB* db, SymbolIdx sym);