Fix warnings

Author: asfernandes

src/dsql/pass1.cpp

@@ -279,8 +279,6 @@ bool InvalidReferenceFinder::visit(ExprNode* node)
 	if (!node)
 		return false;
 
-	bool invalid = false;
-
 	// ASF: What we do in this function is the verification of all fields/dbkeys (or any parent
 	// expression involving them) are present in the passed node list.
 	// That makes valid:
@@ -732,7 +730,7 @@ void PASS1_ambiguity_check(DsqlCompilerScratch* dsqlScratch,
 
 bool PASS1_compare_alias(const QualifiedName& contextAlias, const QualifiedName& lookupAlias)
 {
-	return lookupAlias == contextAlias || lookupAlias.schema.isEmpty() && lookupAlias.object == contextAlias.object;
+	return lookupAlias == contextAlias || (lookupAlias.schema.isEmpty() && lookupAlias.object == contextAlias.object);
 }
 
 
@@ -1443,8 +1441,6 @@ void PASS1_expand_select_node(DsqlCompilerScratch* dsqlScratch, ExprNode* node,
 
 		if (context->ctx_relation)
 		{
-			thread_db* const tdbb = JRD_get_thread_data();
-
 			for (dsql_fld* field = context->ctx_relation->rel_fields; field; field = field->fld_next)
 			{
 				DEV_BLKCHK(field, dsql_type_fld);

src/intl/charsets/cs_koi8u.h

@@ -7,7 +7,6 @@
    -------------------------------------------- */
 
 
-static const int UNICODE_REPLACEMENT_CHARACTER = 0xFFFD;
 static const int CANT_MAP_CHARACTER = 0;
 
 static const USHORT to_unicode_map[256] = {

src/jrd/optimizer/Optimizer.cpp

@@ -3165,8 +3165,6 @@ bool Optimizer::getEquiJoinKeys(NestConst<ValueExprNode>& node1,
 string Optimizer::getStreamName(StreamType stream)
 {
 	const auto tail = &csb->csb_rpt[stream];
-	const auto* relation = tail->csb_relation;
-	const auto* procedure = tail->csb_procedure;
 	const auto* alias = tail->csb_alias;
 
 	string name = tail->getName().toQuotedString();