oracle/graal · error · ExperimentParserTypeError

Failed to parse experiment {experimentId} in {resource}: exp

Error message

Failed to parse experiment {experimentId} in {resource}: expected position to be an instance of Integer but got "{actualObject}"

What it means

While converting an optimization's position map, parseOptimization throws ExperimentParserTypeError when a position value is not a java.lang Integer — the optimization log encodes each inlining position as method-name -> bci, and every bci must be a JSON number that decodes to Integer. The error names the experiment, file, the 'position' property, the expected type and the offending object.

Source

Thrown at compiler/src/org.graalvm.profdiff/src/org/graalvm/profdiff/parser/CompilationUnitTreeParser.java:157

            } else {
                optimizationPhase.addChild(parseOptimizationPhase(childMap));
            }
        }
        return optimizationPhase;
    }

    private Optimization parseOptimization(ExperimentJSONParser.JSONMap optimization) throws ExperimentParserTypeError {
        String optimizationName = optimization.property(OptimizationLogImpl.OPTIMIZATION_NAME_PROPERTY).asString();
        String eventName = optimization.property(OptimizationLogImpl.EVENT_NAME_PROPERTY).asString();
        ExperimentJSONParser.JSONLiteral positionObject = optimization.property(OptimizationLogImpl.POSITION_PROPERTY);
        Position position = Position.EMPTY;
        if (!positionObject.isNull()) {
            MapCursor<String, Object> cursor = positionObject.asMap().getInnerMap().getEntries();
            List<String> methodNames = new ArrayList<>();
            List<Integer> bcis = new ArrayList<>();
            while (cursor.advance()) {
                if (!(cursor.getValue() instanceof Integer)) {
                    throw new ExperimentParserTypeError(experimentId, fileView.getSymbolicPath(), OptimizationLogImpl.POSITION_PROPERTY, Integer.class, cursor.getValue());
                }
                methodNames.add(Method.removeMethodVariantKey(cursor.getKey()));
                bcis.add((Integer) cursor.getValue());
            }
            position = Position.create(methodNames, bcis);
        }
        EconomicMap<String, Object> properties = optimization.getInnerMap();
        properties.removeKey(OptimizationLogImpl.OPTIMIZATION_NAME_PROPERTY);
        properties.removeKey(OptimizationLogImpl.EVENT_NAME_PROPERTY);
        properties.removeKey(OptimizationLogImpl.POSITION_PROPERTY);
        return new Optimization(optimizationName, eventName, position, properties.isEmpty() ? null : properties);
    }
}

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Regenerate the optimization log with the matching GraalVM/profdiff version instead of editing it by hand.
2. If post-processing logs, keep bcis as unquoted JSON integers.
3. Validate the file: every entry of each 'position' object must map a string method name to an integer.

Example fix

// before (log content)
{"name":"inlining","event":"...","position":{"m(int)":"7"}}
// after
{"name":"inlining","event":"...","position":{"m(int)":7}}

// Validate a position object before handing the log to profdiff
Object pos = optimization.get("position");
if (pos instanceof Map<?,?> m) {
    for (Object v : m.values()) if (!(v instanceof Integer)) throw new IllegalArgumentException("Non-integer bci: " + v);
}

static boolean positionsAreIntegerBcis(Map<?,?> position) {
    return position.values().stream().allMatch(v -> v instanceof Integer);
}

try {
    parser.parse();
} catch (ExperimentParserTypeError e) {
    // message names file, 'position', expected Integer, and the actual value; fix the JSON
}

When it happens

Trigger: An optimization log whose position map contains a non-integer bci, e.g. "position": {"m(int)": "42"} (string), a float bci, or a null. Usually produced by a hand-edited log or a mismatched/buggy optimization-log writer version.

Common situations: Editing or programmatically generating optimization logs; JSON serializers that quote numbers or emit doubles; mixing logs produced by one GraalVM version with a profdiff from another whose schema drifted.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Failed to parse experiment {experimentId} in {resource}: exp
• Failed to parse experiment {experimentId} in compilation uni
• The provided optimization log path does not denote a directo
• Failed to parse experiment {experimentId} in {resource}: {me
• Failed to serialize ${op} due to: ${cause}

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/779c1f9a3498e4d3. Report an issue: GitHub.