cql: remove unused functions

It seems that the following functions are never used, delete them:
 * `function::has_reference_to`
 * `functions::get_overload_count`
 * `to_identifiers` in column_identifier.hh
 * `single_column_relation::get_map_key`

Tests: unit(dev, debug)

Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200606115149.1770453-1-pa.solodovnikov@scylladb.com>

cql3/column_identifier.hh

@@ -139,16 +139,6 @@ static inline
     return def.column_specification->name;
 }
 
-static inline
-std::vector<::shared_ptr<column_identifier>> to_identifiers(const std::vector<const column_definition*>& defs) {
-    std::vector<::shared_ptr<column_identifier>> r;
-    r.reserve(defs.size());
-    for (auto&& def : defs) {
-        r.push_back(to_identifier(*def));
-    }
-    return r;
-}
-
 }
 
 namespace std {

cql3/functions/abstract_function.hh

@@ -95,10 +95,6 @@ public:
         return _name.keyspace == ks_name && _name.name == function_name;
     }
 
-    virtual bool has_reference_to(function& f) const override {
-        return false;
-    }
-
     virtual sstring column_name(const std::vector<sstring>& column_names) const override {
         return format("{}({})", _name, join(", ", column_names));
     }

cql3/functions/as_json_function.hh

@@ -144,10 +144,6 @@ public:
         return false;
     }
 
-    virtual bool has_reference_to(function& f) const override {
-        return false;
-    }
-
     virtual sstring column_name(const std::vector<sstring>& column_names) const override {
         return "[json]";
     }

cql3/functions/function.hh

@@ -82,7 +82,6 @@ public:
 
     virtual void print(std::ostream& os) const = 0;
     virtual bool uses_function(const sstring& ks_name, const sstring& function_name) const = 0;
-    virtual bool has_reference_to(function& f) const = 0;
 
     /**
      * Returns the name of the function to use within a ResultSet.

cql3/functions/functions.cc

@@ -158,11 +158,6 @@ functions::make_arg_spec(const sstring& receiver_ks, const sstring& receiver_cf,
                                    fun.arg_types()[i]);
 }
 
-int
-functions::get_overload_count(const function_name& name) {
-    return _declared.count(name);
-}
-
 inline
 shared_ptr<function>
 make_to_json_function(data_type t) {

cql3/functions/functions.hh

@@ -69,7 +69,6 @@ private:
 public:
     static lw_shared_ptr<column_specification> make_arg_spec(const sstring& receiver_ks, const sstring& receiver_cf,
             const function& fun, size_t i);
-    static int get_overload_count(const function_name& name);
 public:
     static shared_ptr<function> get(database& db,
                                     const sstring& keyspace,

cql3/single_column_relation.hh

@@ -108,10 +108,6 @@ public:
         return _entity;
     }
 
-    ::shared_ptr<term::raw> get_map_key() {
-        return _map_key;
-    }
-
     ::shared_ptr<term::raw> get_value() {
         return _value;
     }