allow 'else fail' for all if nodes on root or in

then or else part of such an if node, and not just for
if nodes on root or in else part of such if nodes

backendC/CleanCompilerSources/codegen1.c

@@ -3668,6 +3668,25 @@ static int generate_code_for_push_node (NodeP node,int asp,int bsp,struct esc *e
 #endif
 }
 
+#ifdef CLEAN2
+int contains_fail (NodeP node_p)
+{
+	while (node_p->node_kind==IfNode){
+		NodeP else_node_p;
+	
+		else_node_p=node_p->node_arguments->arg_next->arg_next->arg_node;
+		while (else_node_p->node_kind==IfNode)
+			else_node_p=else_node_p->node_arguments->arg_next->arg_next->arg_node;
+		
+		if (else_node_p->node_kind==NormalNode && else_node_p->node_symbol->symb_kind==fail_symb)
+			return 1;
+
+		node_p=node_p->node_arguments->arg_next->arg_node;
+	}
+	return 0;
+}
+#endif
+
 int generate_code_for_root_node (NodeP node,int asp,int bsp,struct esc *esc_p,NodeDefP defs,StateP result_state_p,
 								 SavedNidStateS **save_states_p,AbNodeIdsP ab_node_ids_p)
 {
@@ -3719,11 +3738,13 @@ int generate_code_for_root_node (NodeP node,int asp,int bsp,struct esc *esc_p,No
 			return generate_code_for_root_node (node,asp,bsp,esc_p,defs,result_state_p,save_states_p,ab_node_ids_p);
 		default:
 		{
+#ifndef CLEAN2
 			NodeP else_node;	
 
 			else_node=node;
 			while (else_node->node_kind==IfNode)
 				else_node=else_node->node_arguments->arg_next->arg_next->arg_node;
+#endif
 
 			return CodeRhsNodeDefs (node,defs,asp,bsp,save_states_p,*result_state_p,esc_p,ab_node_ids_p->a_node_ids,
 					ab_node_ids_p->b_node_ids,
@@ -3732,7 +3753,11 @@ int generate_code_for_root_node (NodeP node,int asp,int bsp,struct esc *esc_p,No
 #else
 					NULL,
 #endif
+#ifdef CLEAN2
+					!contains_fail (node));
+#else
 					!(else_node->node_kind==NormalNode && else_node->node_symbol->symb_kind==fail_symb));
+#endif
 		}
 	}
 }

backendC/CleanCompilerSources/codegen3.c

@@ -1130,6 +1130,10 @@ static void CodeRootUpdateNode (Node root,NodeId rootid,int asp,int bsp,CodeGenN
 	}
 }
 
+#ifdef CLEAN2
+extern int contains_fail (NodeP node_p);
+#endif
+
 static int CodeRootNode (Node root,NodeId rootid,int asp,int bsp,CodeGenNodeIdsP code_gen_node_ids_p,StateS resultstate,struct esc *esc_p)
 {
 	switch (root->node_kind){
@@ -1166,11 +1170,20 @@ static int CodeRootNode (Node root,NodeId rootid,int asp,int bsp,CodeGenNodeIdsP
 	
 			if (thenlab.lab_mod==NULL)
 				GenLabelDefinition (&thenlab);
-
+#ifdef CLEAN2
+			{
+			int needs_next_alt;
+			
+			needs_next_alt=
+#endif
 			CodeRhsNodeDefsAndRestoreNodeIdStates (then_arg->arg_node,root->node_then_node_defs,asp,bsp,resultstate,esc_p,
 				code_gen_node_ids_p->a_node_ids,code_gen_node_ids_p->b_node_ids,
 				root->node_else_node_id_ref_counts,
+#ifdef CLEAN2
+				!contains_fail (then_arg->arg_node)
+#else
 				True
+#endif
 /*
 				code_gen_node_ids_p->doesnt_fail
 */
@@ -1186,9 +1199,18 @@ static int CodeRootNode (Node root,NodeId rootid,int asp,int bsp,CodeGenNodeIdsP
 				
 				return 1;
 			} else
-				return CodeRhsNodeDefsAndRestoreNodeIdStates (else_node,root->node_else_node_defs,asp,bsp,resultstate,esc_p,
+#ifdef CLEAN2
+				needs_next_alt = needs_next_alt |
+#else
+				return 
+#endif
+				CodeRhsNodeDefsAndRestoreNodeIdStates (else_node,root->node_else_node_defs,asp,bsp,resultstate,esc_p,
 								 						code_gen_node_ids_p->a_node_ids,code_gen_node_ids_p->b_node_ids,
 								 						NULL,code_gen_node_ids_p->doesnt_fail);
+#ifdef CLEAN2
+				return needs_next_alt;
+			}
+#endif
 		}
 		case NodeIdNode:
 			if (rootid==NULL){

backendC/CleanCompilerSources/pattern_match.c

@@ -1719,6 +1719,10 @@ static NodeIdRefCountListP duplicate_node_id_ref_count_list (NodeIdRefCountListP
 	return new_node_id_ref_count_list;
 }
 
+#ifdef CLEAN2
+extern int contains_fail (NodeP node_p);
+#endif
+
 static int determine_failing_cases_and_adjust_ref_counts (NodeP node,NodeIdRefCountListP *node_id_ref_count_list_p)
 {
 	switch (node->node_kind){
@@ -1864,6 +1868,9 @@ static int determine_failing_cases_and_adjust_ref_counts (NodeP node,NodeIdRefCo
 		case GuardNode:
 			return determine_failing_cases_and_adjust_ref_counts (node->node_arguments->arg_next->arg_node,node_id_ref_count_list_p);
 		case IfNode:
+#ifdef CLEAN2
+			return contains_fail (node);
+#else
 		{
 			NodeP else_node;
 			
@@ -1873,6 +1880,7 @@ static int determine_failing_cases_and_adjust_ref_counts (NodeP node,NodeIdRefCo
 			
 			return else_node->node_kind==NormalNode && else_node->node_symbol->symb_kind==fail_symb;
 		}
+#endif
 		default:
 			return False;
 	}