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:
- interface
build_end
protected static long build_end
Timing data -- when did we end state and table building
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
emit_end
protected static long emit_end
Timing data -- when did we finish emitting code
expect_conflicts
protected static int expect_conflicts
User option -- number of conflicts to expect
final_time
protected static long final_time
Timing data -- when were we completely done
first_end
protected static long first_end
Timing data -- when did we end first set calculation
include_non_terms
protected static boolean include_non_terms
User option -- should we include non terminal symbol numbers in the
symbol constant class.
input_file
protected static BufferedInputStream input_file
Input file. This is a buffered version of System.in.
lr_values
protected static boolean lr_values
User option -- should generator generate code for left/right values?
machine_end
protected static long machine_end
Timing data -- when did we end state machine construction
no_summary
protected static boolean no_summary
User option -- do not print a summary.
nullability_end
protected static long nullability_end
Timing data -- when did we end nullability calculation
opt_compact_red
protected static boolean opt_compact_red
User option -- do we compact tables by making most common reduce the
default action
opt_do_debug
protected static boolean opt_do_debug
User option -- do we run produce extra debugging messages
opt_dump_grammar
protected static boolean opt_dump_grammar
User option -- do we produce a dump of the grammar
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_show_timing
protected static boolean opt_show_timing
User option -- do we show timing information as a part of the summary
parse_end
protected static long parse_end
Timing data -- when did we end parsing
parser_class_file
protected static PrintWriter parser_class_file
Output file for the parser class.
prelim_end
protected static long prelim_end
Timing data -- when did we end preliminaries
print_progress
protected static boolean print_progress
User option -- do we print progress messages.
reduce_check_end
protected static long reduce_check_end
Timing data -- when did we end checking for non-reduced productions
start_state
protected static lalr_state start_state
Start state in the overall state machine.
start_time
protected static long start_time
Timing data -- when did we start
suppress_scanner
protected static boolean suppress_scanner
User option -- should generator suppress references to
java_cup.runtime.Scanner for compatibility with old runtimes?
sym_interface
protected static boolean sym_interface
User option -- should symbols be put in a class or an interface? [CSA]
symbol_class_file
protected static PrintWriter symbol_class_file
Output file for the symbol constant class.
table_end
protected static long table_end
Timing data -- when did we end table construction
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.
check_unused
protected static void check_unused()
Check for unused symbols. Unreduced productions get checked when
tables are created.
close_files
protected static void close_files()
throws java.io.IOException
Close various files used by the system.
dump_grammar
public static void dump_grammar()
throws internal_error
Produce a human readable dump of the grammar.
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
emit_parser
protected static void emit_parser()
throws internal_error
Call the emit routines necessary to write out the generated parser.
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.
output_produced
- did the system get far enough to generate code.
main
public static void main(argv[] )
throws internal_error,
java.io.IOException,
java.lang.Exception
The main driver for the system.
open_files
protected static void open_files()
Open various files used by the system.
parse_args
protected static void parse_args(argv[] )
Parse command line options and arguments to set various user-option
flags and variables.
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.
plural
protected static String plural(int val)
Helper routine to optionally return a plural or non-plural ending.
val
- the numerical value determining plurality.
show_times
protected static void show_times()
Produce the optional timing summary as part of an overall summary.
timestr
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).
time_val
- the value being formatted (in ms).total_time
- total time percentages are calculated against (in ms).
usage
protected static void usage(String message)
Print a "usage message" that described possible command line options,
then exit.
message
- a specific error message to preface the usage message by.