NationalSecurityAgency/ghidra · warning · JDOMException

No context_register element or global element in gdis option

Error message

No context_register element or global element in gdis options file

What it means

Thrown by parseGdisOptionsFile() as a JDOMException when the gdis options XML file has neither a <context_register> element nor a <global> element under the root. A <global> alone is acceptable (optstring-only); a <context_register> alone is acceptable; but the complete absence of both means the file carries no usable configuration. (This is caught internally and logged; config fields are reset.)

Source

Thrown at Ghidra/Extensions/SleighDevTools/src/main/java/ghidra/app/util/disassemble/GNUExternalDisassembler.java:225

			try (InputStream fis = gdisOpts.getInputStream()) {
				Document doc = sax.build(fis);
				Element rootElem = doc.getRootElement();
				Element globalElement = rootElem.getChild("global");
				if (globalElement != null) {
					globalDisassemblerOptions = globalElement.getAttributeValue("optstring");
				}
				Element contextRegisterElement = rootElem.getChild("context_register");
				if (contextRegisterElement == null) {
					//no context_register element found in the xml file 
					//this is not necessarily an error - might only be a global optstring
					//global optstring has already been parsed, so we're done
					if (globalElement != null) {
						Msg.info(this,
							"no context register element in " + gdisOpts.getAbsolutePath());
						return;
					}
					//no context register element or global element, error
					throw new JDOMException(
						"No context_register element or global element in gdis options file");
				}
				if (contextRegisterElement.getContentSize() == 0) {
					throw new JDOMException("No context register name provided.");
				}
				String contextRegisterName = contextRegisterElement.getContent(0).getValue();
				contextRegister = lang.getRegister(contextRegisterName);
				if (contextRegister == null) {
					//the context register named in the xml file does not exist in the sleigh language
					//this is an error
					throw new JDOMException("Unknown context register " + contextRegisterName +
						" for language " + lang.getLanguageID().getIdAsString());
				}
				valueToOptionString = new HashMap<>();
				valueToDisplayPrefix = new HashMap<>();
				Element options = rootElem.getChild("options");
				List<Element> optList = options.getChildren("option");
				for (Element opt : optList) {

View on GitHub (pinned to d5f144c24d)

Solutions

1. Add at least a <global optstring="..."/> or a properly populated <context_register> element to the options XML.
2. Validate the options file against a known-good one from a working language (e.g. an x86 gdis options file).
3. If external disassembly isn't needed for this language, remove the options file so the integration is not attempted.

Example fix

<!-- before -->
<gdis>
</gdis>

<!-- after -->
<gdis>
  <global optstring="-M"/>
</gdis>

import org.jdom2.Element;
Element root = doc.getRootElement();
boolean hasGlobal = root.getChild("global") != null;
boolean hasCtx = root.getChild("context_register") != null;
if (!hasGlobal && !hasCtx) {
    // options file is empty of usable config; add one before relying on it
}

public boolean gdisOptionsHasUsableConfig(Element root) {
    return root.getChild("global") != null || root.getChild("context_register") != null;
}

try {
    config.parseGdisOptionsFile(fileName);
} catch (JDOMException e) {
    if (e.getMessage().contains("context_register element or global element")) {
        // external disassembler disabled for this language; degrade gracefully
    } else throw e;
}

When it happens

Trigger: A language's gdis options file (.gdis or named options file next to the .slaspec) that is empty, has only an unrelated root, or is a stub missing both required elements.

Common situations: Hand-editing a gdis options file and deleting both elements; a newly added language whose options file was created as a placeholder; corruption during an upgrade that stripped elements.

Related errors

• No context register name provided.
• Not a Sleigh Language:
• Unknown context register
• Error: disassemble_fn is NULL. Nothing I can do.\n
• Invalid byte_order: {}

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/2e2db58f7f1aa670. Report an issue: GitHub.