apache/skywalking · error · IllegalArgumentException

Cannot resolve — no matching codegen path. Parser type: …

Error message

Cannot resolve {desc} — no matching codegen path. Parser type: {parserType}, inputType: {inputTypeName}

What it means

Generic catch-all thrown at LAL compile time when the value codegen cannot map an expression onto any known path: it is not a local def variable, not a literal, not tag()/sourceAttribute(), not a parsed.*/log.* chain, and not a parenthesized expression. The code fails fast at boot instead of silently generating null-producing Java. The message includes the parser type and input type to explain which resolution paths were available.

Solutions

1. Check the function name in the message against the supported set: tag(), sourceAttribute(), json()/yaml()/text() parsers, toJson()/toJsonArray(), and def-variable references
2. If the identifier is meant to be a variable, declare it first with def name = ...
3. For field access, qualify the root explicitly as parsed.* or log.*
4. For JSON path extraction, use json{...} parser plus parsed.* or toJson(...) on a string

Example fix

# before
filter {
  extractor {
    service jsonPath("$.svc")
  }
}

# after
filter {
  json { }
  extractor {
    service parsed.svc as String
  }
}

When it happens

Trigger: Calling an unknown or misspelled function (e.g. jsonPath("x"), regexp("x") instead of the supported built-ins); using a bare identifier that was never declared with def; a function call whose name matches none of the codegen branches for the current parser type.

Common situations: Misspelling a built-in function; assuming a v1 Groovy feature exists in the v2 compiler; referencing an identifier defined in another rule or outside the extractor; using a function only valid in a different parser context (e.g. h.group(...) TEXT-only helpers).

Related errors

• Unknown identifier used as method argument
• Cannot resolve getter
• Failed to compile LAL expression
• Operator ' ' requires numeric operands; got non-numeric…
• sourceAttribute() requires exactly one string literal…

AI-assisted analysis of apache/skywalking@102af09b4a (2026-08-14). Data as JSON: /api/errors/2902574bf7c0e7dd. Report an issue: GitHub.

Appendix: source

Thrown at oap-server/analyzer/log-analyzer/src/main/java/org/apache/skywalking/oap/log/analyzer/v2/compiler/LALValueCodegen.java:842

        // Check for def variable reference
        if (!value.getSegments().isEmpty()) {
            final String primaryName = value.getSegments().get(0);
            final LALClassGenerator.LocalVarInfo localVar =
                genCtx.localVars.get(primaryName);
            if (localVar != null) {
                LALDefCodegen.generateDefVarChain(sb, localVar, chain, genCtx);
                return;
            }
        }

        // No matching codegen path — fail at compile time instead of silently
        // generating null.
        if (chain.isEmpty()) {
            final String desc = value.getFunctionCallName() != null
                ? "function call '" + value.getFunctionCallName() + "(...)'"
                : "expression '" + value.getSegments() + "'";
            throw new IllegalArgumentException(
                "Cannot resolve " + desc + " — no matching codegen path. "
                    + "Parser type: " + genCtx.parserType
                    + (genCtx.inputType != null
                        ? ", inputType: " + genCtx.inputType.getName() : ""));
        }
        // Treat as parsed ref
        generateParsedAccess(sb, chain, genCtx);
    }

    // ==================== Parenthesized expression ====================

    /**
     * Generates code for a parenthesized expression with optional type cast
     * and method chain.
     *
     * <p>LAL: {@code (parsed.component as String).trim()}
     * <br>Generated: {@code h.toStr(h.mapVal("component")).trim()}
     */

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