From ae999f9c92217d7cfcdad99bea06b588797faaca Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Thu, 1 Feb 2018 22:47:22 -0800
Subject: [PATCH] size_t Query*::symbol_idx -> Maybe<Id<void>>

---
 src/indexer.h |  2 ++
 src/query.cc  | 18 +++++++++---------
 src/query.h   | 10 +++++-----
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/src/indexer.h b/src/indexer.h
index 4db78fbd..5c54be0f 100644
--- a/src/indexer.h
+++ b/src/indexer.h
@@ -42,6 +42,8 @@ struct Id {
 
   Id() : id(-1) {}  // Needed for containers and Maybe<Id>. Do not use directly.
   explicit Id(size_t id) : id(id) {}
+  template <typename U>
+  explicit Id(Id<U> o) : id(o.id) {}
 
   // Needed for google::dense_hash_map.
   explicit operator size_t() const { return id; }
diff --git a/src/query.cc b/src/query.cc
index 29e3001a..bde0ef88 100644
--- a/src/query.cc
+++ b/src/query.cc
@@ -795,8 +795,8 @@ void QueryDatabase::RemoveUsrs(SymbolKind usr_kind,
     case SymbolKind::Type: {
       for (const Usr& usr : to_remove) {
         QueryType& type = types[usr_to_type[usr].id];
-        if (type.symbol_idx != size_t(-1))
-          symbols[type.symbol_idx].kind = SymbolKind::Invalid;
+        if (type.symbol_idx)
+          symbols[type.symbol_idx->id].kind = SymbolKind::Invalid;
         type.def = nullopt;
       }
       break;
@@ -804,8 +804,8 @@ void QueryDatabase::RemoveUsrs(SymbolKind usr_kind,
     case SymbolKind::Func: {
       for (const Usr& usr : to_remove) {
         QueryFunc& func = funcs[usr_to_func[usr].id];
-        if (func.symbol_idx != size_t(-1))
-          symbols[func.symbol_idx].kind = SymbolKind::Invalid;
+        if (func.symbol_idx)
+          symbols[func.symbol_idx->id].kind = SymbolKind::Invalid;
         func.def = nullopt;
       }
       break;
@@ -813,8 +813,8 @@ void QueryDatabase::RemoveUsrs(SymbolKind usr_kind,
     case SymbolKind::Var: {
       for (const Usr& usr : to_remove) {
         QueryVar& var = vars[usr_to_var[usr].id];
-        if (var.symbol_idx != size_t(-1))
-          symbols[var.symbol_idx].kind = SymbolKind::Invalid;
+        if (var.symbol_idx)
+          symbols[var.symbol_idx->id].kind = SymbolKind::Invalid;
         var.def = nullopt;
       }
       break;
@@ -954,11 +954,11 @@ void QueryDatabase::ImportOrUpdate(
   }
 }
 
-void QueryDatabase::UpdateSymbols(size_t* symbol_idx,
+void QueryDatabase::UpdateSymbols(Maybe<Id<void>>* symbol_idx,
                                   SymbolKind kind,
                                   size_t idx) {
-  if (*symbol_idx == -1) {
-    *symbol_idx = symbols.size();
+  if (!symbol_idx->has_value()) {
+    *symbol_idx = Id<void>(symbols.size());
     symbols.push_back(SymbolIdx(kind, idx));
   }
 }
diff --git a/src/query.h b/src/query.h
index 1e9efca8..babd1cad 100644
--- a/src/query.h
+++ b/src/query.h
@@ -213,7 +213,7 @@ struct QueryFile {
   using DefUpdate = WithFileContent<Def>;
 
   optional<Def> def;
-  size_t symbol_idx = (size_t)-1;
+  Maybe<Id<void>> symbol_idx;
 
   explicit QueryFile(const std::string& path) {
     def = Def();
@@ -243,7 +243,7 @@ struct QueryType {
   std::vector<QueryTypeId> derived;
   std::vector<QueryVarId> instances;
   std::vector<QueryLocation> uses;
-  size_t symbol_idx = (size_t)-1;
+  Maybe<Id<void>> symbol_idx;
 
   explicit QueryType(const Usr& usr) : usr(usr) {}
 };
@@ -264,7 +264,7 @@ struct QueryFunc {
   std::vector<QueryLocation> declarations;
   std::vector<QueryFuncId> derived;
   std::vector<QueryFuncRef> callers;
-  size_t symbol_idx = (size_t)-1;
+  Maybe<Id<void>> symbol_idx;
 
   explicit QueryFunc(const Usr& usr) : usr(usr) {}
 };
@@ -280,7 +280,7 @@ struct QueryVar {
   optional<Def> def;
   std::vector<QueryLocation> declarations;
   std::vector<QueryLocation> uses;
-  size_t symbol_idx = (size_t)-1;
+  Maybe<Id<void>> symbol_idx;
 
   explicit QueryVar(const Usr& usr) : usr(usr) {}
 };
@@ -386,7 +386,7 @@ struct QueryDatabase {
   void ImportOrUpdate(const std::vector<QueryType::DefUpdate>& updates);
   void ImportOrUpdate(const std::vector<QueryFunc::DefUpdate>& updates);
   void ImportOrUpdate(const std::vector<QueryVar::DefUpdate>& updates);
-  void UpdateSymbols(size_t* symbol_idx, SymbolKind kind, size_t idx);
+  void UpdateSymbols(Maybe<Id<void>>* symbol_idx, SymbolKind kind, size_t idx);
   std::string_view GetSymbolDetailedName(size_t symbol_idx) const;
   std::string_view GetSymbolShortName(size_t symbol_idx) const;