parser-helper: Add utility class for flex/bison based parsers

2014-05-15 11:28:06 +02:00
parent 3784633fa5
commit 3cb8016f0e
4 changed files with 408 additions and 3 deletions
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2014 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup parser_helper parser_helper
+ * @{ @ingroup utils
+ */
+
+#ifndef PARSER_HELPER_H_
+#define PARSER_HELPER_H_
+
+#include <collections/array.h>
+#include <bio/bio_writer.h>
+
+typedef struct parser_helper_t parser_helper_t;
+typedef struct parser_helper_file_t parser_helper_file_t;
+
+/**
+ * Helper class for flex/bison based parsers.
+ *
+ * <code>PREFIX</code> equals whatever is configure with
+ * <code>%option prefix</code> resp. <code>%name-prefix</code>.
+ */
+struct parser_helper_t {
+
+	/**
+	 * A user defined parser context object.
+	 */
+	const void *context;
+
+	/**
+	 * Opaque object allocated by the lexer, should be set with:
+	 * @code
+	 * PREFIXlex_init_extra(helper, &helper->scanner).
+	 * @endcode
+	 */
+	void *scanner;
+
+	/**
+	 * Function to determine the current line number (defined by the lexer).
+	 *
+	 * Basically, this should be assigned to <code>PREFIXget_lineno</code>.
+	 *
+	 * @param scanner	the lexer
+	 * @return			current line number
+	 */
+	int (*get_lineno)(void *scanner);
+
+	/**
+	 * Get the current file.
+	 *
+	 * @return			current file, or NULL
+	 */
+	parser_helper_file_t *(*file_current)(parser_helper_t *this);
+
+	/**
+	 * Resolves the given include pattern, relative to the location of the
+	 * current file.
+	 *
+	 * Call file_next() to open the next file.
+	 *
+	 * @param pattern	file pattern
+	 */
+	void (*file_include)(parser_helper_t *this, char *pattern);
+
+	/**
+	 * Get the next file to process.
+	 *
+	 * This will return NULL if all files matching the most recent pattern
+	 * have been handled. If there are other patterns the next call will then
+	 * return the next file matching the previous pattern.
+	 *
+	 * When hitting <code>\<\<EOF\>\></code> first call
+	 * @code
+	 * PREFIXpop_buffer_state(yyscanner);
+	 * @endcode
+	 * then call this method to check if there are more files to include for
+	 * the most recent call to file_include(), if so, call
+	 * @code
+	 * PREFIXset_in(file->file, helper->scanner);
+	 * PREFIXpush_buffer_state(PREFIX_create_buffer(file->file, YY_BUF_SIZE,
+	 * 						helper->scanner), helper->scanner);
+	 * @endcode
+	 *
+	 * If there are no more files to process check
+	 * <code>YY_CURRENT_BUFFER</code> and if it is FALSE call yyterminate().
+	 *
+	 * @return			next file to process, or NULL (see comment)
+	 */
+	parser_helper_file_t *(*file_next)(parser_helper_t *this);
+
+	/**
+	 * Start parsing a string, discards any currently stored data.
+	 */
+	void (*string_init)(parser_helper_t *this);
+
+	/**
+	 * Append the given string.
+	 *
+	 * @param str		string to append
+	 */
+	void (*string_add)(parser_helper_t *this, char *str);
+
+	/**
+	 * Extract the current string buffer as null-terminated string. Can only
+	 * be called once per string.
+	 *
+	 * @return			allocated string
+	 */
+	char *(*string_get)(parser_helper_t *this);
+
+	/**
+	 * Destroy this instance.
+	 */
+	void (*destroy)(parser_helper_t *this);
+};
+
+struct parser_helper_file_t {
+
+	/**
+	 * File name
+	 */
+	char *name;
+
+	/**
+	 * File stream
+	 */
+	FILE *file;
+};
+
+/**
+ * Log the given message either as error or warning
+ *
+ * @param level		log level
+ * @param ctx		current parser context
+ * @param fmt		error message format
+ * @param ...		additional arguments
+ */
+#define parser_helper_log(level, ctx, fmt, ...) ({ \
+	parser_helper_file_t *_file = (ctx)->file_current(ctx); \
+	int _line = (ctx)->get_lineno ? (ctx)->get_lineno((ctx)->scanner) : 0; \
+	if (_file) {\
+		DBG##level(DBG_CFG, "%s:%d: " fmt, _file->name, _line, ##__VA_ARGS__); \
+	} else { \
+		DBG##level(DBG_CFG, fmt, ##__VA_ARGS__); \
+	} \
+})
+
+#define PARSER_DBG1(ctx, fmt, ...) parser_helper_log(1, ctx, fmt, ##__VA_ARGS__)
+#define PARSER_DBG2(ctx, fmt, ...) parser_helper_log(2, ctx, fmt, ##__VA_ARGS__)
+#define PARSER_DBG3(ctx, fmt, ...) parser_helper_log(3, ctx, fmt, ##__VA_ARGS__)
+
+/**
+ * Create a parser helper object
+ *
+ * @param context		user defined parser context
+ * @return				parser helper
+ */
+parser_helper_t *parser_helper_create(void *context);
+
+#endif /** PARSER_HELPER_H_ @}*/