import jdk.nashorn.internal.runtime.Timing; //导入依赖的package包/类
/**
 * Execute parse and return the resulting function node.
 * Errors will be thrown and the error manager will contain information
 * if parsing should fail
 *
 * This should be used to create one and only one function node
 *
 * @param scriptName name for the script, given to the parsed FunctionNode
 * @param startPos start position in source
 * @param len length of parse
 * @param allowPropertyFunction if true, "get" and "set" are allowed as first tokens of the program, followed by
 * a property getter or setter function. This is used when reparsing a function that can potentially be defined as a
 * property getter or setter in an object literal.
 *
 * @return function node resulting from successful parse
 */
public FunctionNode parse(final String scriptName, final int startPos, final int len, final boolean allowPropertyFunction) {
    final boolean isTimingEnabled = env.isTimingEnabled();
    final long t0 = isTimingEnabled ? System.nanoTime() : 0L;
    log.info(this, " begin for '", scriptName, "'");

    try {
        stream = new TokenStream();
        lexer  = new Lexer(source, startPos, len, stream, scripting && !env._no_syntax_extensions, reparsedFunction != null);
        lexer.line = lexer.pendingLine = lineOffset + 1;
        line = lineOffset;

        // Set up first token (skips opening EOL.)
        k = -1;
        next();
        // Begin parse.
        return program(scriptName, allowPropertyFunction);
    } catch (final Exception e) {
        handleParseException(e);

        return null;
    } finally {
        final String end = this + " end '" + scriptName + "'";
        if (isTimingEnabled) {
            env._timing.accumulateTime(toString(), System.nanoTime() - t0);
            log.info(end, "' in ", Timing.toMillisPrint(System.nanoTime() - t0), " ms");
        } else {
            log.info(end);
        }
    }
}
 

import jdk.nashorn.internal.runtime.Timing; //导入依赖的package包/类
/**
 * Execute parse and return the resulting function node.
 * Errors will be thrown and the error manager will contain information
 * if parsing should fail
 *
 * This should be used to create one and only one function node
 *
 * @param scriptName name for the script, given to the parsed FunctionNode
 * @param startPos start position in source
 * @param len length of parse
 * @param reparseFlags flags provided by {@link RecompilableScriptFunctionData} as context for
 * the code being reparsed. This allows us to recognize special forms of functions such
 * as property getters and setters or instances of ES6 method shorthand in object literals.
 *
 * @return function node resulting from successful parse
 */
public FunctionNode parse(final String scriptName, final int startPos, final int len, final int reparseFlags) {
    final boolean isTimingEnabled = env.isTimingEnabled();
    final long t0 = isTimingEnabled ? System.nanoTime() : 0L;
    log.info(this, " begin for '", scriptName, "'");

    try {
        stream = new TokenStream();
        lexer  = new Lexer(source, startPos, len, stream, scripting && !env._no_syntax_extensions, env._es6, reparsedFunction != null);
        lexer.line = lexer.pendingLine = lineOffset + 1;
        line = lineOffset;

        scanFirstToken();
        // Begin parse.
        return program(scriptName, reparseFlags);
    } catch (final Exception e) {
        handleParseException(e);

        return null;
    } finally {
        final String end = this + " end '" + scriptName + "'";
        if (isTimingEnabled) {
            env._timing.accumulateTime(toString(), System.nanoTime() - t0);
            log.info(end, "' in ", Timing.toMillisPrint(System.nanoTime() - t0), " ms");
        } else {
            log.info(end);
        }
    }
}
 

import jdk.nashorn.internal.runtime.Timing; //导入依赖的package包/类
/**
 * Execute parse and return the resulting function node.
 * Errors will be thrown and the error manager will contain information
 * if parsing should fail
 *
 * This should be used to create one and only one function node
 *
 * @param scriptName name for the script, given to the parsed FunctionNode
 * @param startPos start position in source
 * @param len length of parse
 * @param allowPropertyFunction if true, "get" and "set" are allowed as first tokens of the program, followed by
 * a property getter or setter function. This is used when reparsing a function that can potentially be defined as a
 * property getter or setter in an object literal.
 *
 * @return function node resulting from successful parse
 */
public FunctionNode parse(final String scriptName, final int startPos, final int len, final boolean allowPropertyFunction) {
    final boolean isTimingEnabled = env.isTimingEnabled();
    final long t0 = isTimingEnabled ? System.nanoTime() : 0L;
    log.info(this, " begin for '", scriptName, "'");

    try {
        stream = new TokenStream();
        lexer  = new Lexer(source, startPos, len, stream, scripting && !env._no_syntax_extensions, env._es6, reparsedFunction != null);
        lexer.line = lexer.pendingLine = lineOffset + 1;
        line = lineOffset;

        scanFirstToken();
        // Begin parse.
        return program(scriptName, allowPropertyFunction);
    } catch (final Exception e) {
        handleParseException(e);

        return null;
    } finally {
        final String end = this + " end '" + scriptName + "'";
        if (isTimingEnabled) {
            env._timing.accumulateTime(toString(), System.nanoTime() - t0);
            log.info(end, "' in ", Timing.toMillisPrint(System.nanoTime() - t0), " ms");
        } else {
            log.info(end);
        }
    }
}
 

import jdk.nashorn.internal.runtime.Timing; //导入依赖的package包/类
/**
 * Execute parse and return the resulting function node.
 * Errors will be thrown and the error manager will contain information
 * if parsing should fail
 *
 * @param scriptName name for the script, given to the parsed FunctionNode
 *
 * @return function node resulting from successful parse
 */
public FunctionNode parse(final String scriptName) {
    final long t0 = Timing.isEnabled() ? System.currentTimeMillis() : 0L;
    LOG.info(this, " begin for '", scriptName, "'");

    try {
        stream = new TokenStream();
        lexer  = new Lexer(source, stream, scripting && !env._no_syntax_extensions);

        // Set up first token (skips opening EOL.)
        k = -1;
        next();

        // Begin parse.
        return program(scriptName);
    } catch (final Exception e) {
        handleParseException(e);

        return null;
    } finally {
        final String end = this + " end '" + scriptName + "'";
        if (Timing.isEnabled()) {
            Timing.accumulateTime(toString(), System.currentTimeMillis() - t0);
            LOG.info(end, "' in ", (System.currentTimeMillis() - t0), " ms");
        } else {
            LOG.info(end);
        }
    }
}