Add lenses

- this adds the lens framework, although there are currently no interesting
  lenses.  display_args.c was mostly moved to lens_default.c

1 files changed, 62 insertions, 0 deletions

diff --git a/lens.c b/lens.c
new file mode 100644
index 0000000..07cdcca
--- /dev/null
+++ b/lens.c
@@ -0,0 +1,62 @@
+/*
+ * This file is part of ltrace.
+ * Copyright (C) 2011 Petr Machata, Red Hat Inc.
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <assert.h>
+
+#include "lens.h"
+#include "lens_default.h"
+#include "type.h"
+#include "value.h"
+
+int
+format_argument(FILE *stream, struct value *value,
+		struct value_dict *arguments)
+{
+	/* Find the closest enclosing parental value whose type has a
+	 * lens assigned.  */
+	struct value *parent;
+	for (parent = value; (parent != NULL && parent->type != NULL
+			      && parent->type->lens == NULL);
+	     parent = parent->parent)
+		;
+
+	struct lens *lens = &default_lens;
+	if (parent != NULL && parent->type != NULL
+	    && parent->type->lens != NULL)
+		lens = parent->type->lens;
+
+	return lens_format(lens, stream, value, arguments);
+}
+
+int
+lens_format(struct lens *lens, FILE *stream, struct value *value,
+	    struct value_dict *arguments)
+{
+	assert(lens->format_cb != NULL);
+	return lens->format_cb(lens, stream, value, arguments);
+}
+
+void
+lens_destroy(struct lens *lens)
+{
+	if (lens != NULL
+	    && lens->destroy_cb != NULL)
+		lens->destroy_cb(lens);
+}