Table of Contents
The ANTLR plugin extends the Java plugin to add support for generating parsers using ANTLR.
The ANTLR plugin supports ANTLR version 2, 3 and 4.
To use the ANTLR plugin, include the following in your build script:
The ANTLR plugin adds a number of tasks to your project, as shown below.
Table 55.1. ANTLR plugin - tasks
| Task name | Depends on | Type | Description |
generateGrammarSource
|
- | AntlrTask |
Generates the source files for all production ANTLR grammars. |
generateTestGrammarSource
|
- | AntlrTask |
Generates the source files for all test ANTLR grammars. |
generate
|
- | AntlrTask |
Generates the source files for all ANTLR grammars for the given source set. |
The ANTLR plugin adds the following dependencies to tasks added by the Java plugin.
Table 55.2. ANTLR plugin - additional task dependencies
| Task name | Depends on |
| compileJava | generateGrammarSource |
| compileTestJava | generateTestGrammarSource |
compileSourceSetJava |
generateSourceSetGrammarSource |
Table 55.3. ANTLR plugin - project layout
| Directory | Meaning |
src/main/antlr
|
Production ANTLR grammar files. If the ANTLR grammar is organized in packages, the structure in the antlr folder should reflect the package structure. This ensures that the generated sources end up in the correct target subfolder. |
src/test/antlr
|
Test ANTLR grammar files. |
src/
|
ANTLR grammar files for the given source set. |
The ANTLR plugin adds an antlr dependency configuration which provides the ANTLR implementation to use.
The following example shows how to use ANTLR version 3.
Example 55.2. Declare ANTLR version
build.gradle
repositories {
mavenCentral()
}
dependencies {
antlr "org.antlr:antlr:3.5.2" // use ANTLR version 3
// antlr "org.antlr:antlr4:4.5" // use ANTLR version 4
}
If no dependency is declared, antlr:antlr:2.7.7 will be used as the default.
To use a different ANTLR version add the appropriate dependency to the antlr dependency configuration as above.
The ANTLR plugin adds the following properties to each source set in the project.
Table 55.4. ANTLR plugin - source set properties
| Property name | Type | Default value | Description |
antlr
|
SourceDirectorySet (read-only)
|
Not null |
The ANTLR grammar files of this source set. Contains all .g or .g4 files found in the ANTLR
source directories, and excludes all other types of files.
|
antlr.srcDirs
|
Set<File>. Can set using anything described in Section 18.5, “Specifying a set of input files”.
|
[
|
The source directories containing the ANTLR grammar files of this source set. |
The ANTLR tool is executed in a forked process.
This allows fine grained control over memory settings for the ANTLR process.
To set the heap size of a ANTLR process, the maxHeapSize property
of AntlrTask can be used.
To pass additional command-line arguments, append to the arguments property
of AntlrTask.
Example 55.3. setting custom max heap size and extra arguments for ANTLR
build.gradle
generateGrammarSource {
maxHeapSize = "64m"
arguments += ["-visitor", "-long-messages"]
}