CUP Parser Generator for Java 10k · java_cup.Main

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"]
-interface: emit symbol constant interface, rather than class
-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
-nopositions: don't generate the positions code
-noscanner: don't refer to java_cup.runtime.Scanner in the parser (for compatibility with old runtimes)
-version: print version information for JavaCUP and halt.

Field Summary

Modifier and Type	Field and 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 BufferedInputStream	input_file Input file.
protected static boolean	lr_values User option -- should generator generate code for left/right values?
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 PrintWriter	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 boolean	suppress_scanner User option -- should generator suppress references to java_cup.runtime.Scanner for compatibility with old runtimes?
protected static boolean	sym_interface User option -- should symbols be put in a class or an interface?
protected static PrintWriter	symbol_class_file Output file for the symbol constant class.
protected static long	table_end Timing data -- when did we end table construction

Access	Constructor and Description
private	Main() Only constructor is private, so we do not allocate any instances of this class.

Method Summary

Modifier and Type	Method and 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.
public static void	dump_grammar() Produce a human readable dump of the grammar.
public static void	dump_machine() Produce a (semi-) human readable dump of the complete viable prefix recognition state machine.
public 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 did the system get far enough to generate code. 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.
public static void	main(String[] an array of strings containing command line arguments. argv) The main driver for the system.
protected static void	open_files() Open various files used by the system.
protected static void	parse_args(String[] the command line arguments to be parsed. 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 String	plural(int the numerical value determining plurality. 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 String	timestr(long the value being formatted (in ms). time_val, long total time percentages are calculated against (in ms). 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(String a specific error message to preface the usage message by. message) Print a "usage message" that described possible command line options, then exit.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

action_table	back to summary
protected static parse_action_table action_table Resulting parse action table.

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

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

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

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

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

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

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

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

input_file	back to summary
protected static BufferedInputStream input_file Input file. This is a buffered version of System.in.

lr_values	back to summary
protected static boolean lr_values User option -- should generator generate code for left/right values?

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

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

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

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

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

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

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

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

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

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

parser_class_file	back to summary
protected static PrintWriter parser_class_file Output file for the parser class.

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

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

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

reduce_table	back to summary
protected static parse_reduce_table reduce_table Resulting reduce-goto table.

start_state	back to summary
protected static lalr_state start_state Start state in the overall state machine.

start_time	back to summary
protected static long start_time Timing data -- when did we start

suppress_scanner	back to summary
protected static boolean suppress_scanner User option -- should generator suppress references to java_cup.runtime.Scanner for compatibility with old runtimes?

sym_interface	back to summary
protected static boolean sym_interface User option -- should symbols be put in a class or an interface? [CSA]

symbol_class_file	back to summary
protected static PrintWriter symbol_class_file Output file for the symbol constant class.

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

Constructor Detail

Main	back to summary
private Main() Only constructor is private, so we do not allocate any instances of this class.

Method Detail

build_parser	back to summary
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.

build_parser

back to summary

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.

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

close_files	back to summary
protected static void close_files() throws IOException Close various files used by the system.

dump_grammar	back to summary
public static void dump_grammar() throws internal_error Produce a human readable dump of the grammar.

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

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

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

emit_summary	back to 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:boolean did the system get far enough to generate code.

emit_summary

back to 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:boolean: did the system get far enough to generate code.

main	back to summary
public static void main(String[] argv) throws internal_error, IOException, Exception The main driver for the system. Parameters argv:String[] an array of strings containing command line arguments.

main

back to summary

public static void main(String[] argv) throws internal_error, IOException, Exception

The main driver for the system.

Parameters

argv:String[]: an array of strings containing command line arguments.

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

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

parse_args

back to summary

protected static void parse_args(String[] argv)

Parse command line options and arguments to set various user-option flags and variables.

Parameters

argv:String[]: the command line arguments to be parsed.

parse_grammar_spec	back to summary
protected static void parse_grammar_spec() throws 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.

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

plural

back to summary

protected static String plural(int val)

Helper routine to optionally return a plural or non-plural ending.

Parameters

val:int: the numerical value determining plurality.

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

timestr

back to summary

protected static 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:long: the value being formatted (in ms).
total_time:long: total time percentages are calculated against (in ms).

usage

back to summary

protected static void usage(String message)

Print a "usage message" that described possible command line options, then exit.

Parameters

message:String: a specific error message to preface the usage message by.

public Class Main

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Method Summary

Field Detail

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Method Detail