HHH-9100 - Improve CAST function support

(cherry picked from commit 137c2daf81)

hibernate-core/src/main/antlr/hql-sql.g

@@ -629,7 +629,7 @@ functionCall
         processFunction( #functionCall, inSelect );
         inFunctionCall=false;
     }
-    | #(CAST {inFunctionCall=true;} expr pathAsIdent) {
+    | #(CAST {inFunctionCall=true;} exprOrSubquery pathAsIdent) {
     	processCastFunction( #functionCall, inSelect );
         inFunctionCall=false;
     }

hibernate-core/src/main/antlr/sql-gen.g

@@ -92,8 +92,8 @@ options {
 	      out(")");
 	}
 
-	protected void commaBetweenParameters(String comma) {
+	protected void betweenFunctionArguments() {
-		out(comma);
+		out( ", " );
 	}
 
 	protected void captureExpressionStart() {
@@ -465,11 +465,15 @@ methodCall
 	: #(m:METHOD_CALL i:METHOD_NAME { beginFunctionTemplate(m,i); }
 	 ( #(EXPR_LIST (arguments)? ) )?
 	 { endFunctionTemplate(m); } )
-	| #( c:CAST { beginFunctionTemplate(c,c); } expr castTargetType { endFunctionTemplate(c); } )
+	| #( c:CAST { beginFunctionTemplate(c,c); } castExpression {betweenFunctionArguments();} castTargetType { endFunctionTemplate(c); } )
 	;
 
 arguments
-	: expr ( { commaBetweenParameters(", "); } expr )*
+	: expr ( { betweenFunctionArguments(); } expr )*
+	;
+
+castExpression
+	: selectExpr
 	;
 
 castTargetType

hibernate-core/src/main/java/org/hibernate/dialect/function/CastFunction.java

@@ -60,7 +60,7 @@ public class CastFunction implements SQLFunction {
 	@Override
 	public String render(Type columnType, List args, SessionFactoryImplementor factory) throws QueryException {
 		if ( args.size()!=2 ) {
-			throw new QueryException("cast() requires two arguments");
+			throw new QueryException( "cast() requires two arguments; found : " + args.size() );
 		}
 		final String type = (String) args.get( 1 );
 		final int[] sqlTypeCodes = factory.getTypeResolver().heuristicType( type ).sqlTypes( factory );

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/SqlGenerator.java

@@ -44,6 +44,7 @@ import org.hibernate.hql.internal.ast.util.ASTPrinter;
 import org.hibernate.internal.CoreLogging;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.internal.util.StringHelper;
+import org.hibernate.internal.util.collections.CollectionHelper;
 import org.hibernate.param.ParameterSpecification;
 import org.hibernate.type.Type;
 
@@ -145,8 +146,8 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 	}
 
 	@Override
-	protected void commaBetweenParameters(String comma) {
+	protected void betweenFunctionArguments() {
-		writer.commaBetweenParameters( comma );
+		writer.betweenFunctionArguments();
 	}
 
 	@Override
@@ -241,14 +242,7 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 	interface SqlWriter {
 		void clause(String clause);
 
-		/**
+		void betweenFunctionArguments();
-		 * todo remove this hack
-		 * The parameter is either ", " or " , ". This is needed to pass sql generating tests as the old
-		 * sql generator uses " , " in the WHERE and ", " in SELECT.
-		 *
-		 * @param comma either " , " or ", "
-		 */
-		void commaBetweenParameters(String comma);
 	}
 
 	interface FunctionArgumentsCollectingWriter extends SqlWriter {
@@ -274,7 +268,7 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 		}
 
 		@Override
-		public void commaBetweenParameters(String comma) {
+		public void betweenFunctionArguments() {
 			++argInd;
 		}
 
@@ -288,20 +282,44 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 	 * which catches function arguments.
 	 */
 	class CastFunctionArguments implements FunctionArgumentsCollectingWriter {
-		private final List<String> args = new ArrayList<String>( 3 );
+		private String castExpression;
+		private String castTargetType;
+
+		private boolean startedType;
 
 		@Override
 		public void clause(String clause) {
-			args.add( clause );
+			if ( startedType ) {
+				if ( castTargetType == null ) {
+					castTargetType = clause;
+				}
+				else {
+					castTargetType += clause;
+				}
+			}
+			else {
+				if ( castExpression == null ) {
+					castExpression = clause;
+				}
+				else {
+					castExpression += clause;
+				}
+			}
 		}
 
 		@Override
-		public void commaBetweenParameters(String comma) {
+		public void betweenFunctionArguments() {
-			// todo : should this be an exception?  Its not likely to end well if this method is called here...
+			if ( startedType ) {
+				throw new QueryException( "CAST function should only have 2 arguments" );
+			}
+			startedType = true;
 		}
 
 		public List getArgs() {
-			return args;
+			List<String> rtn = CollectionHelper.arrayList( 2 );
+			rtn.add( castExpression );
+			rtn.add( castTargetType );
+			return rtn;
 		}
 	}
 
@@ -315,8 +333,8 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 		}
 
 		@Override
-		public void commaBetweenParameters(String comma) {
+		public void betweenFunctionArguments() {
-			getStringBuilder().append( comma );
+			getStringBuilder().append( ", " );
 		}
 	}