antlr/antlr4 · error · IllegalArgumentException

text cannot be null

Error message

text cannot be null

What it means

TextChunk represents a literal-text portion of a parse-tree pattern. The constructor throws IllegalArgumentException when text is null because the chunk's whole purpose is to carry literal text used to match token text in the tree.

Source

Thrown at runtime/Java/src/org/antlr/v4/runtime/tree/pattern/TextChunk.java:28

 * Represents a span of raw text (concrete syntax) between tags in a tree
 * pattern string.
 */
class TextChunk extends Chunk {
	/**
	 * This is the backing field for {@link #getText}.
	 */

	private final String text;

	/**
	 * Constructs a new instance of {@link TextChunk} with the specified text.
	 *
	 * @param text The text of this chunk.
	 * @exception IllegalArgumentException if {@code text} is {@code null}.
	 */
	public TextChunk(String text) {
		if (text == null) {
			throw new IllegalArgumentException("text cannot be null");
		}

		this.text = text;
	}

	/**
	 * Gets the raw text of this chunk.
	 *
	 * @return The text of the chunk.
	 */

	public final String getText() {
		return text;
	}

	/**
	 * {@inheritDoc}
	 *

View on GitHub (pinned to 7d5770395b)

Solutions

1. Null-check the text before constructing the chunk, or default to "" if an empty literal is intended
2. Use parser.compileParseTreePattern to let ANTLR parse the pattern string correctly

Example fix

// before
new TextChunk(maybeNull);

// after
new TextChunk(Objects.requireNonNull(text, "text chunk requires literal text"));

Objects.requireNonNull(text, "text chunk must have literal text");

try { new TextChunk(text); } catch (IllegalArgumentException e) { /* reject null literal segment */ }

When it happens

Trigger: Calling new TextChunk(null); indirectly when ParseTreePatternBuilder splits a pattern and a literal segment is unexpectedly null.

Common situations: Programmatically assembling pattern chunks; passing a computed string that can be null (e.g. map lookup miss) into TextChunk.

Related errors

• index cannot be negative
• missing interface implementation
• Fatal error occured while evaluating the names of the gramma
• Error creating an instanceof the ANTLR tool.
• Dependency analysis failed.

AI-assisted analysis of antlr/antlr4@7d5770395b (2026-08-14). Data as JSON: /api/errors/5db0f86c884750e7. Report an issue: GitHub.