Package java_cup

Class Main

  • public class Main
extends java.lang.Object
    This class serves as the main driver for the JavaCup system. It accepts user options and coordinates overall control flow. The main flow of control includes the following activities:
    • Parse user supplied arguments and options.
    • Open output files.
    • Parse the specification from standard input.
    • Check for unused terminals, non-terminals, and productions.
    • Build the state machine, tables, etc.
    • Output the generated code.
    • Close output files.
    • Print a summary if requested.
    Options to the main program include:
    -package name
    specify package generated classes go in [default none]
    -parser name
    specify parser class name [default "parser"]
    -symbols name
    specify name for symbol constant class [default "sym"]
    -nonterms
    put non terminals in symbol constant class
    -expect #
    number of conflicts expected/allowed [default 0]
    -compact_red
    compact tables by defaulting to most frequent reduce
    -nowarn
    don't warn about useless productions, etc.
    -nosummary
    don't print the usual summary of parse states, etc.
    -progress
    print messages to indicate progress of the system
    -time
    print time usage summary
    -dump_grammar
    produce a dump of the symbols and grammar
    -dump_states
    produce a dump of parse state machine
    -dump_tables
    produce a dump of the parse tables
    -dump
    produce a dump of all of the above
    -debug
    turn on debugging messages within JavaCup

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static parse_action_table action_table
      Resulting parse action table.
      protected static long build_end
      Timing data -- when did we end state and table building
      protected static long check_end
      Timing data -- when did we end checking
      protected static long dump_end
      Timing data -- when did we end dumping
      protected static long emit_end
      Timing data -- when did we finish emitting code
      protected static int expect_conflicts
      User option -- number of conflicts to expect
      protected static long final_time
      Timing data -- when were we completely done
      protected static long first_end
      Timing data -- when did we end first set calculation
      protected static boolean include_non_terms
      User option -- should we include non terminal symbol numbers in the symbol constant class.
      protected static java.io.BufferedInputStream input_file
      Input file.
      protected static long machine_end
      Timing data -- when did we end state machine construction
      protected static boolean no_summary
      User option -- do not print a summary.
      protected static long nullability_end
      Timing data -- when did we end nullability calculation
      protected static boolean opt_compact_red
      User option -- do we compact tables by making most common reduce the default action
      protected static boolean opt_do_debug
      User option -- do we run produce extra debugging messages
      protected static boolean opt_dump_grammar
      User option -- do we produce a dump of the grammar
      protected static boolean opt_dump_states
      User option -- do we produce a dump of the state machine
      protected static boolean opt_dump_tables
      User option -- do we produce a dump of the parse tables
      protected static boolean opt_show_timing
      User option -- do we show timing information as a part of the summary
      protected static long parse_end
      Timing data -- when did we end parsing
      protected static java.io.PrintStream parser_class_file
      Output file for the parser class.
      protected static long prelim_end
      Timing data -- when did we end preliminaries
      protected static boolean print_progress
      User option -- do we print progress messages.
      protected static long reduce_check_end
      Timing data -- when did we end checking for non-reduced productions
      protected static parse_reduce_table reduce_table
      Resulting reduce-goto table.
      protected static lalr_state start_state
      Start state in the overall state machine.
      protected static long start_time
      Timing data -- when did we start
      protected static java.io.PrintStream symbol_class_file
      Output file for the symbol constant class.
      protected static long table_end
      Timing data -- when did we end table construction

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      protected static void build_parser()
      Build the (internal) parser from the previously parsed specification.
      protected static void check_unused()
      Check for unused symbols.
      protected static void close_files()
      Close various files used by the system.
      static void dump_grammar()
      Produce a human readable dump of the grammar.
      static void dump_machine()
      Produce a (semi-) human readable dump of the complete viable prefix recognition state machine.
      static void dump_tables()
      Produce a (semi-) human readable dumps of the parse tables
      protected static void emit_parser()
      Call the emit routines necessary to write out the generated parser.
      protected static void emit_summary​(boolean output_produced)
      Emit a long summary message to standard error (System.err) which summarizes what was found in the specification, how many states were produced, how many conflicts were found, etc.
      static void main​(java.lang.String[] argv)
      The main driver for the system.
      protected static void open_files()
      Open various files used by the system.
      protected static void parse_args​(java.lang.String[] argv)
      Parse command line options and arguments to set various user-option flags and variables.
      protected static void parse_grammar_spec()
      Parse the grammar specification from standard input.
      protected static java.lang.String plural​(int val)
      Helper routine to optionally return a plural or non-plural ending.
      protected static void show_times()
      Produce the optional timing summary as part of an overall summary.
      protected static java.lang.String timestr​(long time_val, long total_time)
      Helper routine to format a decimal based display of seconds and percentage of total time given counts of milliseconds.
      protected static void usage​(java.lang.String message)
      Print a "usage message" that described possible command line options, then exit.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • print_progress

        protected static boolean print_progress
        User option -- do we print progress messages.

      • opt_dump_states

        protected static boolean opt_dump_states
        User option -- do we produce a dump of the state machine

      • opt_dump_tables

        protected static boolean opt_dump_tables
        User option -- do we produce a dump of the parse tables

      • opt_dump_grammar

        protected static boolean opt_dump_grammar
        User option -- do we produce a dump of the grammar

      • opt_show_timing

        protected static boolean opt_show_timing
        User option -- do we show timing information as a part of the summary

      • opt_do_debug

        protected static boolean opt_do_debug
        User option -- do we run produce extra debugging messages

      • opt_compact_red

        protected static boolean opt_compact_red
        User option -- do we compact tables by making most common reduce the default action

      • include_non_terms

        protected static boolean include_non_terms
        User option -- should we include non terminal symbol numbers in the symbol constant class.

      • no_summary

        protected static boolean no_summary
        User option -- do not print a summary.

      • expect_conflicts

        protected static int expect_conflicts
        User option -- number of conflicts to expect

      • start_time

        protected static long start_time
        Timing data -- when did we start

      • prelim_end

        protected static long prelim_end
        Timing data -- when did we end preliminaries

      • parse_end

        protected static long parse_end
        Timing data -- when did we end parsing

      • check_end

        protected static long check_end
        Timing data -- when did we end checking

      • dump_end

        protected static long dump_end
        Timing data -- when did we end dumping

      • build_end

        protected static long build_end
        Timing data -- when did we end state and table building

      • nullability_end

        protected static long nullability_end
        Timing data -- when did we end nullability calculation

      • first_end

        protected static long first_end
        Timing data -- when did we end first set calculation

      • machine_end

        protected static long machine_end
        Timing data -- when did we end state machine construction

      • table_end

        protected static long table_end
        Timing data -- when did we end table construction

      • reduce_check_end

        protected static long reduce_check_end
        Timing data -- when did we end checking for non-reduced productions

      • emit_end

        protected static long emit_end
        Timing data -- when did we finish emitting code

      • final_time

        protected static long final_time
        Timing data -- when were we completely done

      • input_file

        protected static java.io.BufferedInputStream input_file
        Input file. This is a buffered version of System.in.

      • parser_class_file

        protected static java.io.PrintStream parser_class_file
        Output file for the parser class.

      • symbol_class_file

        protected static java.io.PrintStream symbol_class_file
        Output file for the symbol constant class.

      • start_state

        protected static lalr_state start_state
        Start state in the overall state machine.

      • action_table

        protected static parse_action_table action_table
        Resulting parse action table.

      • reduce_table

        protected static parse_reduce_table reduce_table
        Resulting reduce-goto table.

    • Method Detail

      • main

        public static void main​(java.lang.String[] argv)
                 throws internal_error,
                        java.io.IOException,
                        java.lang.Exception
        The main driver for the system.
        Parameters:
        argv - an array of strings containing command line arguments.
        Throws:
        internal_error
        java.io.IOException
        java.lang.Exception

      • usage

        protected static void usage​(java.lang.String message)
        Print a "usage message" that described possible command line options, then exit.
        Parameters:
        message - a specific error message to preface the usage message by.

      • parse_args

        protected static void parse_args​(java.lang.String[] argv)
        Parse command line options and arguments to set various user-option flags and variables.
        Parameters:
        argv - the command line arguments to be parsed.

      • open_files

        protected static void open_files()
        Open various files used by the system.

      • close_files

        protected static void close_files()
                           throws java.io.IOException
        Close various files used by the system.
        Throws:
        java.io.IOException

      • parse_grammar_spec

        protected static void parse_grammar_spec()
                                  throws java.lang.Exception
        Parse the grammar specification from standard input. This produces sets of terminal, non-terminals, and productions which can be accessed via static variables of the respective classes, as well as the setting of various variables (mostly in the emit class) for small user supplied items such as the code to scan with.
        Throws:
        java.lang.Exception

      • check_unused

        protected static void check_unused()
        Check for unused symbols. Unreduced productions get checked when tables are created.

      • build_parser

        protected static void build_parser()
                            throws internal_error
        Build the (internal) parser from the previously parsed specification. This includes:
        • Computing nullability of non-terminals.
        • Computing first sets of non-terminals and productions.
        • Building the viable prefix recognizer machine.
        • Filling in the (internal) parse tables.
        • Checking for unreduced productions.
        Throws:
        internal_error

      • emit_parser

        protected static void emit_parser()
                           throws internal_error
        Call the emit routines necessary to write out the generated parser.
        Throws:
        internal_error

      • plural

        protected static java.lang.String plural​(int val)
        Helper routine to optionally return a plural or non-plural ending.
        Parameters:
        val - the numerical value determining plurality.

      • emit_summary

        protected static void emit_summary​(boolean output_produced)
        Emit a long summary message to standard error (System.err) which summarizes what was found in the specification, how many states were produced, how many conflicts were found, etc. A detailed timing summary is also produced if it was requested by the user.
        Parameters:
        output_produced - did the system get far enough to generate code.

      • show_times

        protected static void show_times()
        Produce the optional timing summary as part of an overall summary.

      • timestr

        protected static java.lang.String timestr​(long time_val,
                                          long total_time)
        Helper routine to format a decimal based display of seconds and percentage of total time given counts of milliseconds. Note: this is broken for use with some instances of negative time (since we don't use any negative time here, we let if be for now).
        Parameters:
        time_val - the value being formatted (in ms).
        total_time - total time percentages are calculated against (in ms).

      • dump_grammar

        public static void dump_grammar()
                         throws internal_error
        Produce a human readable dump of the grammar.
        Throws:
        internal_error

      • dump_machine

        public static void dump_machine()
        Produce a (semi-) human readable dump of the complete viable prefix recognition state machine.

      • dump_tables

        public static void dump_tables()
        Produce a (semi-) human readable dumps of the parse tables