Add VariantMap parse stubs for spell-only build

Author: Belzedar94

src/variant.cpp

@@ -86,6 +86,26 @@ void VariantMap::init() {
     add("spell-chess", spell_chess_variant());
 }
 
+// Spell-only build: keep variant parsing entry points as no-ops for link
+// compatibility with UCI VariantPath handling in other build configurations.
+template <bool DoCheck>
+void VariantMap::parse_istream(std::istream& file) {
+    (void)file;
+    // No-op: variants are hardcoded in this build.
+    // If DoCheck is true, callers expect validation side effects; none apply here.
+}
+
+template <bool DoCheck>
+void VariantMap::parse(const std::string& data) {
+    std::istringstream ss(data);
+    parse_istream<DoCheck>(ss);
+}
+
+template void VariantMap::parse_istream<true>(std::istream& file);
+template void VariantMap::parse_istream<false>(std::istream& file);
+template void VariantMap::parse<true>(const std::string& data);
+template void VariantMap::parse<false>(const std::string& data);
+
 
 // Pre-calculate derived properties
 Variant* Variant::conclude() {

src/variant.h

@@ -36,7 +36,7 @@ namespace Stockfish {
 /// Variant struct stores information needed to determine the rules of a variant.
 
 struct Variant {
-  std::string variantTemplate = "fairy";
+  std::string variantTemplate = "spell-chess";
   std::string pieceToCharTable = "-";
   int pocketSize = 0;
   Rank maxRank = RANK_8;
@@ -249,8 +249,12 @@ struct Variant {
 class VariantMap : public std::map<std::string, const Variant*> {
 public:
   void init();
-  template <bool DoCheck> void parse(std::string path);
-  template <bool DoCheck> void parse_istream(std::istream& file);
+  // Spell-only build: keep parsing entry points as no-ops for link compatibility
+  // with UCI VariantPath handling in other build configurations.
+  template <bool DoCheck>
+  void parse_istream(std::istream& file);
+  template <bool DoCheck>
+  void parse(const std::string& data);
   void clear_all();
   std::vector<std::string> get_keys();