HHH-19240 Reduce memory consumption by left factoring some HQL parse rules

Author: beikov

hibernate-core/src/main/antlr/org/hibernate/grammars/hql/HqlParser.g4

@@ -427,19 +427,13 @@ pathContinuation
  *		* VALUE( path )
  * 		* KEY( path )
  * 		* path[ selector ]
- * 		* ARRAY_GET( embeddableArrayPath, index ).path
- * 		* COALESCE( array1, array2 )[ selector ].path
  */
 syntacticDomainPath
 	: treatedNavigablePath
 	| collectionValueNavigablePath
 	| mapKeyNavigablePath
 	| simplePath indexedPathAccessFragment
 	| simplePath slicedPathAccessFragment
-	| toOneFkReference
-	| function pathContinuation
-	| function indexedPathAccessFragment pathContinuation?
-	| function slicedPathAccessFragment
 	;
 
 /**
@@ -748,7 +742,14 @@ primaryExpression
 	| entityVersionReference							# EntityVersionExpression
 	| entityNaturalIdReference							# EntityNaturalIdExpression
 	| syntacticDomainPath pathContinuation?				# SyntacticPathExpression
-	| function											# FunctionExpression
+ // ARRAY_GET( embeddableArrayPath, index ).path
+ // COALESCE( array1, array2 )[ selector ].path
+ // COALESCE( array1, array2 )[ start : end ]
+	| function (
+          pathContinuation
+        | slicedPathAccessFragment
+        | indexedPathAccessFragment pathContinuation?
+        )?											    # FunctionExpression
 	| generalPathFragment								# GeneralPathExpression
 	;
 
@@ -1108,6 +1109,7 @@ function
 	| columnFunction
 	| jsonFunction
 	| xmlFunction
+	| toOneFkReference
 	| genericFunction
 	;
 

hibernate-core/src/main/java/org/hibernate/query/hql/internal/SemanticQueryBuilder.java

@@ -1831,8 +1831,34 @@ public Object visitGeneralPathExpression(HqlParser.GeneralPathExpressionContext
 	}
 
 	@Override
-	public SqmExpression<?> visitFunctionExpression(HqlParser.FunctionExpressionContext ctx) {
-		return (SqmExpression<?>) ctx.function().accept( this );
+	public Object visitFunctionExpression(HqlParser.FunctionExpressionContext ctx) {
+		final var slicedFragmentsCtx = ctx.slicedPathAccessFragment();
+		if ( slicedFragmentsCtx != null ) {
+			final List<HqlParser.ExpressionContext> slicedFragments = slicedFragmentsCtx.expression();
+			return getFunctionDescriptor( "array_slice" ).generateSqmExpression(
+					List.of(
+							(SqmTypedNode<?>) visitFunction( ctx.function() ),
+							(SqmTypedNode<?>) slicedFragments.get( 0 ).accept( this ),
+							(SqmTypedNode<?>) slicedFragments.get( 1 ).accept( this )
+					),
+					null,
+					queryEngine()
+			);
+		}
+		else {
+			final var function = (SqmExpression<?>) visitFunction( ctx.function() );
+			final var indexedPathAccessFragment = ctx.indexedPathAccessFragment();
+			final var pathContinuation = ctx.pathContinuation();
+			if ( indexedPathAccessFragment == null && pathContinuation == null ) {
+				return function;
+			}
+			else {
+				return visitPathContinuation(
+						visitIndexedPathAccessFragment( (SemanticPathPart) function, indexedPathAccessFragment ),
+						pathContinuation
+				);
+			}
+		}
 	}
 
 	@Override
@@ -3533,11 +3559,6 @@ else if ( attributes.size() >1 ) {
 		throw new FunctionArgumentException( "Argument '" + sqmPath.getNavigablePath()
 				+ "' of 'naturalid()' does not resolve to an entity type" );
 	}
-//
-//	@Override
-//	public Object visitToOneFkExpression(HqlParser.ToOneFkExpressionContext ctx) {
-//		return visitToOneFkReference( (HqlParser.ToOneFkReferenceContext) ctx.getChild( 0 ) );
-//	}
 
 	@Override
 	public SqmFkExpression<?> visitToOneFkReference(HqlParser.ToOneFkReferenceContext ctx) {
@@ -5673,33 +5694,6 @@ else if ( ctx.collectionValueNavigablePath() != null ) {
 		else if ( ctx.mapKeyNavigablePath() != null ) {
 			return visitMapKeyNavigablePath( ctx.mapKeyNavigablePath() );
 		}
-		else if ( ctx.toOneFkReference() != null ) {
-			return visitToOneFkReference( ctx.toOneFkReference() );
-		}
-		else if ( ctx.function() != null ) {
-			final var slicedFragmentsCtx = ctx.slicedPathAccessFragment();
-			if ( slicedFragmentsCtx != null ) {
-				final List<HqlParser.ExpressionContext> slicedFragments = slicedFragmentsCtx.expression();
-				return getFunctionDescriptor( "array_slice" ).generateSqmExpression(
-						List.of(
-								(SqmTypedNode<?>) visitFunction( ctx.function() ),
-								(SqmTypedNode<?>) slicedFragments.get( 0 ).accept( this ),
-								(SqmTypedNode<?>) slicedFragments.get( 1 ).accept( this )
-						),
-						null,
-						queryEngine()
-				);
-			}
-			else {
-				return visitPathContinuation(
-						visitIndexedPathAccessFragment(
-								(SemanticPathPart) visitFunction( ctx.function() ),
-								ctx.indexedPathAccessFragment()
-						),
-						ctx.pathContinuation()
-				);
-			}
-		}
 		else if ( ctx.simplePath() != null && ctx.indexedPathAccessFragment() != null ) {
 			return visitIndexedPathAccessFragment( visitSimplePath( ctx.simplePath() ), ctx.indexedPathAccessFragment() );
 		}