Class BytecodeNormalizer

java.lang.Object

org.ek9lang.compiler.backend.jvm.BytecodeNormalizer

public final class BytecodeNormalizer
extends Object

Normalizes JVM bytecode output from javap for stable test comparisons.

Normalization removes fragile elements like constant pool indices, line number tables, and debug information while preserving essential instruction sequences and method signatures.

This utility is specifically designed for testing bytecode generation by enabling reliable comparison of expected vs actual bytecode output.

Method Summary

Modifier and Type	Method	Description
(package private) static String	executeJavap(Path classFile)	Execute javap on class file and capture output.
static String	normalize(byte[] classBytes)	Normalize bytecode from .class file bytes with default settings.
static String	normalize(byte[] classBytes, boolean includeLineNumberTable, boolean includeSourceDebugExtension)	Normalize bytecode from .class file bytes with configuration options.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

normalize

public static String normalize(byte[] classBytes)

Normalize bytecode from .class file bytes with default settings. Includes debug information (LineNumberTable and SourceDebugExtension).

Parameters:

classBytes - Compiled .class file bytes

Returns:

Normalized bytecode text suitable for test comparison

Throws:

RuntimeException - if normalization fails

normalize

public static String normalize(byte[] classBytes,
 boolean includeLineNumberTable,
 boolean includeSourceDebugExtension)

Normalize bytecode from .class file bytes with configuration options.

Parameters:

classBytes - Compiled .class file bytes

includeLineNumberTable - Include LineNumberTable debug information

includeSourceDebugExtension - Include SourceDebugExtension (SMAP) information

Returns:

Normalized bytecode text suitable for test comparison

Throws:

RuntimeException - if normalization fails

executeJavap

static String executeJavap(Path classFile)
                    throws Exception

Execute javap on class file and capture output.

Merges stderr into stdout to prevent the classic Process deadlock where reading stdout blocks while stderr pipe buffer fills up. The Process is destroyed in a finally block to release native resources (file descriptors) which otherwise leak and cause "Too many open files" on CI runners after 200+ invocations.

Package-private for RawJavap, which runs javap without the normalization.

Parameters:

classFile - Path to .class file

Returns:

Raw javap output

Throws:

Exception - if javap execution fails