Add exdump utility

Add tool for dumping the contents of .ex files, which contain various
structured data used by the game (tables, lists, trees).

The dump format uses a C-like syntax which should be relatively easy to
parse back in.

include/system4/ex.h

@@ -0,0 +1,105 @@
+/* Copyright (C) 2019 Nunuhara Cabbage <nunuhara@haniwa.technology>
+ *
+ * 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, see <http://gnu.org/licenses/>.
+ */
+
+#ifndef SYSTEM4_EX_H
+#define SYSTEM4_EX_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+enum ex_value_type {
+	EX_INT = 1,
+	EX_FLOAT = 2,
+	EX_STRING = 3,
+	EX_TABLE = 4,
+	EX_LIST = 5,
+	EX_TREE = 6
+};
+
+struct ex_value {
+	enum ex_value_type type;
+	union {
+		int32_t i;
+		float f;
+		struct string *s;
+		struct ex_table *t;
+		struct ex_list *list;
+		struct ex_tree *tree;
+	};
+};
+
+struct ex_field {
+	enum ex_value_type type;
+	struct string *name;
+	int32_t uk0;
+	int32_t uk1;
+	int32_t uk2;
+	uint32_t nr_subfields;
+	struct ex_field *subfields;
+};
+
+struct ex_table {
+	uint32_t nr_fields;
+	struct ex_field *fields;
+	uint32_t nr_columns;
+	uint32_t nr_rows;
+	struct ex_value **rows;
+};
+
+struct ex_list_item {
+	uint32_t size;
+	struct ex_value value;
+};
+
+struct ex_list {
+	uint32_t nr_items;
+	struct ex_list_item *items;
+};
+
+struct ex_leaf {
+	uint32_t size;
+	struct string *name;
+	struct ex_value value;
+};
+
+struct ex_tree {
+	struct string *name;
+	bool is_leaf;
+	union {
+		struct {
+			uint32_t nr_children;
+			struct ex_tree *children;
+		};
+		struct ex_leaf leaf;
+	};
+};
+
+struct ex_block {
+	size_t size;
+	struct string *name;
+	struct ex_value val;
+};
+
+struct ex {
+	uint32_t nr_blocks;
+	struct ex_block *blocks;
+};
+
+struct ex *ex_read(const char *path);
+void ex_free(struct ex *ex);
+
+#endif /* SYSTE4_EX_H */