JavaCC Gradle Plugin

outputDir

File

<project.buildDir>/generated/javacc/<config name>

Generated code will be written under this directory.

args

List<String>

Additional command line arguments passed to javaCC

sourceSetName

String

'main'

Generated source code will be added to the source set.

inputFile

File

The input jj-File for the code generation.

packageName

String

A special package name for the code generation. The output directory will be extended with this configuration.

The following variables are integer variables.

lookahead

int

LOOKAHEAD: The number of tokens to look ahead before making a decision at a choice point during parsing. The default value is 1.
The smaller this number, the faster the parser. This number may be overridden for specific productions within the grammar as described later.
See the description of the lookahead algorithm for complete details on how lookahead works.

choiceAmbiguityCheck

int

CHOICE_AMBIGUITY_CHECK: This is an integer option whose default value is 2.
This is the number of tokens considered in checking choices of the form "A | B | …​" for ambiguity.
For example, if there is a common two token prefix for both A and B, but no common three token prefix,
(assume this option is set to 3) then JavaCC can tell you to use a lookahead of 3 for disambiguation purposes.
And if A and B have a common three token prefix, then JavaCC only tell you that you need to have a lookahead of 3 or more.
Increasing this can give you more comprehensive ambiguity information at the cost of more processing time.
For large grammars such as the Java grammar, increasing this number any further causes the checking to take too much time.

otherAmbiguityCheck

int

OTHER_AMBIGUITY_CHECK: This is an integer option whose default value is 1.
This is the number of tokens considered in checking all other kinds of choices (i.e., of the forms "(A)*", "(A)+", and "(A)?")
for ambiguity. This takes more time to do than the choice checking, and hence the default value is set to 1 rather than 2.

The following variables will be interpreted as boolean.

staticParam

String

STATIC: This is a boolean option whose default value is true.
If true, all methods and class variables are specified as static in the generated parser and token manager.
This allows only one parser object to be present, but it improves the performance of the parser.
To perform multiple parses during one run of your Java program, you will have to call the ReInit()
method to reinitialize your parser if it is static. If the parser is non-static, you may use the "new" operator
to construct as many parsers as you wish. These can all be used simultaneously from different threads.

supportClassVisibilityPublic

String

SUPPORT_CLASS_VISIBILITY_PUBLIC: This is a boolean option whose default value is true.
The default action is to generate support classes (such as Token.java, ParseException.java etc) with Public visibility.
If set to false, the classes will be generated with package-private visibility.

debugParser

String

DEBUG_PARSER: This is a boolean option whose default value is false.
This option is used to obtain debugging information from the generated parser. Setting this option to true causes
the parser to generate a trace of its actions. Tracing may be disabled by calling the method disable_tracing()
in the generated parser class. Tracing may be subsequently enabled by calling the method enable_tracing() in the generated parser class.

debugLookahead

String

DEBUG_LOOKAHEAD: This is a boolean option whose default value is false.
Setting this option to true causes the parser to generate all the tracing information it does when the option
DEBUG_PARSER is true, and in addition, also causes it to generated a trace of actions performed during lookahead operation.

debugTokenManager

String

DEBUG_TOKEN_MANAGER: This is a boolean option whose default value is false.
This option is used to obtain debugging information from the generated token manager. Setting this option to true causes
the token manager to generate a trace of its actions. This trace is rather large and should only be used when you have a
lexical error that has been reported to you and you cannot understand why. Typically, in this situation, you can determine
the problem by looking at the last few lines of this trace.

errorReporting

String

ERROR_REPORTING: This is a boolean option whose default value is true.
Setting it to false causes errors due to parse errors to be reported in somewhat less detail. The only reason to set
this option to false is to improve performance.

javaUnicodeEscape

String

JAVA_UNICODE_ESCAPE: This is a boolean option whose default value is false.
When set to true, the generated parser uses an input stream object that processes Java Unicode escapes (\u…​) before
sending characters to the token manager. By default, Java Unicode escapes are not processed. This option is ignored if
either of options USER_TOKEN_MANAGER, USER_CHAR_STREAM is set to true.

unicodeInput

String

UNICODE_INPUT: This is a boolean option whose default value is false.
When set to true, the generated parser uses uses an input stream object that reads Unicode files. By default,
ASCII files are assumed. This option is ignored if either of options USER_TOKEN_MANAGER, USER_CHAR_STREAM is set to true.

ignoreCase

String

IGNORE_CASE: This is a boolean option whose default value is false.
Setting this option to true causes the generated token manager to ignore case in the token specifications and the input files.
This is useful for writing grammars for languages such as HTML. It is also possible to localize the effect of IGNORE_CASE
by using an alternate mechanism described later.

commonTokenAction

String

COMMON_TOKEN_ACTION: This is a boolean option whose default value is false.
When set to true, every call to the token manager’s method "getNextToken" (see the description of the Java Compiler Compiler API)
will cause a call to a used defined method "CommonTokenAction" after the token has been scanned in by the token manager.
The user must define this method within the TOKEN_MGR_DECLS section. The signature of this method is: void CommonTokenAction(Token t)

userTokenManager

String

USER_TOKEN_MANAGER: This is a boolean option whose default value is false.
The default action is to generate a token manager that works on the specified grammar tokens. If this option is set
to true, then the parser is generated to accept tokens from any token manager of type "TokenManager" - this interface
is generated into the generated parser directory.

userCharStream

String

USER_CHAR_STREAM: This is a boolean option whose default value is false.
The default action is to generate a character stream reader as specified by the options JAVA_UNICODE_ESCAPE and UNICODE_INPUT.
The generated token manager receives characters from this stream reader. If this option is set to true, then the token manager
is generated to read characters from any character stream reader of type "CharStream.java". This file is generated into the
generated parser directory. This option is ignored if USER_TOKEN_MANAGER is set to true.

buildParser

String

BUILD_PARSER: This is a boolean option whose default value is true.
The default action is to generate the parser file ("MyParser.java" in the above example). When set to false, the parser
file is not generated. Typically, this option is set to false when you wish to generate only the token manager and use
it without the associated parser.

buildTokenManager

String

BUILD_TOKEN_MANAGER: This is a boolean option whose default value is true.
The default action is to generate the token manager file ("MyParserTokenManager.java" in the above example).
When set to false the token manager file is not generated. The only reason to set this option to false is to save
some time during parser generation when you fix problems in the parser part of the grammar file and leave the lexical
specifications untouched.

tokenManagerUsesParser

String

TOKEN_MANAGER_USES_PARSER: This is a boolean option whose default value is false.
When set to true, the generated token manager will include a field called parser that references the instantiating parser
instance (of type MyParser in the above example). The main reason for having a parser in a token manager is using some of
its logic in lexical actions. This option has no effect if the STATIC option is set to true.

sanityCheck

String

SANITY_CHECK: This is a boolean option whose default value is true.
JavaCC performs many syntactic and semantic checks on the grammar file during parser generation. Some checks such as
detection of left recursion, detection of ambiguity, and bad usage of empty expansions may be suppressed for faster
parser generation by setting this option to false. Note that the presence of these errors (even if they are not detected
and reported by setting this option to false) can cause unexpected behavior from the generated parser.

forceLaCheck

String

FORCE_LA_CHECK: This is a boolean option whose default value is false.
This option setting controls lookahead ambiguity checking performed by JavaCC. By default (when this option is false),
lookahead ambiguity checking is performed for all choice points where the default lookahead of 1 is used. Lookahead
ambiguity checking is not performed at choice points where there is an explicit lookahead specification, or if the option
LOOKAHEAD is set to something other than 1. Setting this option to true performs lookahead ambiguity checking at all choice
points regardless of the lookahead specifications in the grammar file.

cacheTokens

String

CACHE_TOKENS: This is a boolean option whose default value is false.
Setting this option to true causes the generated parser to lookahead for extra tokens ahead of time. This facilitates
some performance improvements. However, in this case (when the option is true), interactive applications may not work
since the parser needs to work synchronously with the availability of tokens from the input stream. In such cases, it’s
best to leave this option at its default value.

keepLineColumn

String

KEEP_LINE_COLUMN: This is a boolean option whose default value is true.
If you set this option to false, the generated CharStream will not have any line/column tracking code. It will be your
responsibility to do it some other way. This is needed for systems which don’t care about giving error messages etc.

The following variables will be interpreted as string.

tokenExtends

String

TOKEN_EXTENDS: This is a string option whose default value is "", meaning that the generated Token class will extend java.lang.Object.
This option may be set to the name of a class that will be used as the base class for the generated Token class.

tokenFactory

String

TOKEN_FACTORY: This is a string option whose default value is "", meaning that Tokens will be created by calling Token.newToken().
If set the option names a Token factory class containing a public static Token newToken(int ofKind, String image) method.

jdkVersion

String

JDK_VERSION: This is a string option whose default value is "1.4"

Method

Parameter

Description

addArg

String

Add an additional command line argument passed to JavaCC

addArgs

List<String>

Add additional command line arguments passed to JavaCC

jjtree

JJTree

Add an additional configuration for JJTree

Property

Type

Default value

Description

The following variables will be interpreted as boolean.

multi

String

MULTI (default: false) Generate a multi mode parse tree. The default for this is false, generating a simple mode parse tree.

nodeDefaultVoid

String

NODE_DEFAULT_VOID (default: false) Instead of making each non-decorated production an indefinite node, make it void instead.

nodeScopeHook

String

NODE_SCOPE_HOOK (default: false) Insert calls to user-defined parser methods on entry and exit of every node scope. See Node Scope Hooks.

nodeUsesParser

String

NODE_USES_PARSER (default: false)JJTree will use an alternate form of the node construction routines where it passes the parser object in.
For example,
public static Node MyNode.jjtCreate(MyParser p, int id);
MyNode(MyParser p, int id);

buildNodeFiles

String

BUILD_NODE_FILES (default: true) Generate sample implementations for SimpleNode and any other nodes used in the grammar.

staticParam

String

STATIC (default: true) Generate code for a static parser. The default for this is true. This must be used consistently with the equivalent JavaCC options.
The value of this option is emitted in the JavaCC source.

trackTokens

String

TRACK_TOKENS (default: false) Insert jjtGetFirstToken(), jjtSetFirstToken(), getLastToken(), and jjtSetLastToken() methods in SimpleNode.
The FirstToken is automatically set up on entry to a node scope; the LastToken is automatically set up on exit from a node scope.

visitor

String

VISITOR (default: false) Insert a jjtAccept() method in the node classes, and generate a visitor implementation with an entry for every node type used in the grammar.

The following variables will be interpreted as string.

nodeClass

String

NODE_CLASS (default: "") If set defines the name of a user-supplied class that will extend SimpleNode. Any tree nodes created will then be subclasses of NODE_CLASS.

nodePrefix

String

'AST'

NODE_PREFIX (default: "AST") The prefix used to construct node class names from node identifiers in multi mode. The default for this is AST.

nodePackage

String

NODE_PACKAGE (default: "") The package to generate the node classes into. The default for this is the parser package.

nodeExtends

String

NODE_EXTENDS (default: "") Deprecated
The superclass for the SimpleNode class. By providing a custom superclass you
may be able to avoid the need to edit the generated SimpleNode.java.

nodeFactory

String

NODE_FACTORY (default: "") Specify a class containing a factory method with following signature to construct nodes: public static Node jjtCreate(int id)
For backwards compatibility, the value false may also be specified, meaning that SimpleNode will be used as the factory class.

visitorDataType

String

VISITOR_DATA_TYPE (default: "Object") If this option is set, it is used in the signature of the generated jjtAccept() methods and the visit() methods as the type of the data argument.

visitorReturnType

String

VISITOR_RETURN_TYPE (default: "Object") If this option is set, it is used in the signature of the generated jjtAccept() methods and the visit() methods as the return type of the method.

visitorException

String

VISITOR_EXCEPTION (default: "") If this option is set, it is used in the signature of the generated jjtAccept() methods and the visit() methods.

args

List<String>

Additional command line arguments passed to jjTree

Method

Parameter

Description

addArg

String

Add an additional command line argument passed to JavaCC

addArgs

List<String>

Add additional command line arguments passed to JavaCC