1 files changed, 160 insertions, 0 deletions
diff --git a/src/commit.c b/src/commit.c
new file mode 100644
index 00000000..473f4bbb
--- /dev/null
+++ b/src/commit.c
@@ -0,0 +1,160 @@
+/*
+ *  Copyright 2015 Adrian Thurston <thurston@complang.org>
+ */
+
+/*  This file is part of Colm.
+ *
+ *  Colm is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  Colm is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with Colm; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+
+#include "config.h"
+#include "debug.h"
+#include "pdarun.h"
+#include "bytecode.h"
+#include "tree.h"
+#include "pool.h"
+
+#include "internal.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+//#define true 1
+//#define false 0
+
+static void commit_clear_parse_tree( program_t *prg, tree_t **sp, parse_tree_t *pt )
+{
+	tree_t **top = vm_ptop();
+
+	if ( pt == 0 )
+		return;
+
+free_tree:
+	if ( pt->next != 0 ) {
+		vm_push_ptree( pt->next );
+	}
+
+	if ( pt->left_ignore != 0 ) {
+		vm_push_ptree( pt->left_ignore );
+	}
+
+	if ( pt->child != 0 ) {
+		vm_push_ptree( pt->child );
+	}
+
+	if ( pt->right_ignore != 0 ) {
+		vm_push_ptree( pt->right_ignore );
+	}
+
+	if ( pt->shadow != 0 ) {
+		colm_tree_downref( prg, sp, pt->shadow->tree );
+		kid_free( prg, pt->shadow );
+	}
+
+	//printf( "commit_parse_tree_free %p\n", pt );
+	parse_tree_free( prg, pt );
+
+	/* Any trees to downref? */
+	if ( sp != top ) {
+		pt = vm_pop_ptree();
+		goto free_tree;
+	}
+}
+
+static int been_committed( parse_tree_t *parse_tree )
+{
+	return parse_tree->flags & PF_COMMITTED;
+}
+
+
+static void commit_forward_recurse( program_t *prg, tree_t **root, parse_tree_t *pt )
+{
+	tree_t **sp = root;
+
+	parse_tree_t *lel = pt;
+
+recurse:
+
+	if ( lel->child != 0 ) {
+		/* There are children. Must process all children first. */
+		vm_push_ptree( lel );
+
+		lel = lel->child;
+		while ( lel != 0 ) {
+			goto recurse;
+			resume:
+			lel = lel->next;
+		}
+
+		lel = vm_pop_ptree();
+	}
+
+	/* Now can execute the reduction action. */
+
+	commit_clear_parse_tree( prg, sp, lel->child );
+	lel->child = 0;
+	pt->flags |= PF_COMMITTED;
+
+	if ( sp != root )
+		goto resume;
+}
+
+void commit_clear( program_t *prg, tree_t **root, struct pda_run *pda_run )
+{
+	tree_t **sp = root;
+	parse_tree_t *pt = pda_run->stack_top;
+
+	/* The top level of the stack is linked right to left. This is the
+	 * traversal order we need for committing. */
+	while ( pt != 0 && !been_committed( pt ) ) {
+		vm_push_ptree( pt );
+		pt = pt->next;
+	}
+
+	while ( sp != root ) {
+		pt = vm_pop_ptree();
+
+		commit_forward_recurse( prg, sp, pt );
+
+		pt->flags |= PF_COMMITTED;
+		pt = pt->next;
+	}
+}
+
+void commit_reduce( program_t *prg, tree_t **root, struct pda_run *pda_run )
+{
+	tree_t **sp = root;
+	parse_tree_t *pt = pda_run->stack_top;
+
+	/* The top level of the stack is linked right to left. This is the
+	 * traversal order we need for committing. */
+	while ( pt != 0 && !been_committed( pt ) ) {
+		vm_push_ptree( pt );
+		pt = pt->next;
+	}
+
+	while ( sp != root ) {
+		pt = vm_pop_ptree();
+
+		commit_clear_parse_tree( prg, sp, pt->child );
+		pt->child = 0;
+
+		pt->flags |= PF_COMMITTED;
+		pt = pt->next;
+	}
+}