Package org.codehaus.groovy.ast.decompiled

Class AsmReferenceResolver

java.lang.Object

org.codehaus.groovy.ast.decompiled.AsmReferenceResolver

public class AsmReferenceResolver
extends Object

Helper class for resolving class references encountered in bytecode stubs decompiled from compiled classes. Bridges between ASM's internal type descriptors/names and Groovy's ClassNode representation by consulting both classes currently being compiled in the compilation unit and already-loaded classes via the ClassNodeResolver.

Resolution Strategy

AsmReferenceResolver implements a two-tier lookup strategy:

1. Compilation-time classes: First checks the compilation unit's AST for classes being compiled in the same batch. This ensures references to companion classes resolve correctly.
2. Runtime classes: If not found in the compilation unit, delegates to the ClassNodeResolver, which consults already-compiled and third-party classes.

Type Descriptor Handling

The resolver handles multiple bytecode formats:

• Primitive types: Resolved via ClassHelper.make(String) (e.g., "I" → int.class).
• Object types: Converted from JVMS internal names (e.g., "java/lang/String") to dot notation and resolved via resolveClass(String).
• Array types: Handled recursively by resolveType(Type) and marked via ClassNode.makeArray().

Error Handling

The resolver distinguishes between two resolution modes:

• resolveClass(String) - Throws NoClassDefFoundError if the class cannot be resolved. Used when a type is required.
• resolveClassNullable(String) - Returns null if the class cannot be resolved. Used for optional type information (e.g., exception types).

Thread Safety

AsmReferenceResolver instances are typically created once per compilation unit and are thread-safe for concurrent read access. The underlying ClassNodeResolver and CompilationUnit manage their own synchronization.

See Also:

• DecompiledClassNode
• AsmDecompiler
• ClassNodeResolver
• CompilationUnit

Constructor Summary

Constructors

Constructor	Description
AsmReferenceResolver(ClassNodeResolver resolver, CompilationUnit unit)	Creates an ASM reference resolver for a compilation unit.

Method Summary

Modifier and Type	Method	Description
ClassNode	resolveClass(String className)	Resolves a fully qualified class name to a ClassNode.
ClassNode	resolveClassNullable(String className)	Attempts to resolve a fully qualified class name to a ClassNode, returning null if not found.
Class	resolveJvmClass(String name)	Resolves a fully qualified class name to a runtime JVM Class object.
ClassNode	resolveType(org.objectweb.asm.Type type)	Resolves an ASM Type to a ClassNode, handling array types by wrapping element types.

Methods inherited from class java.lang.Object

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

Constructor Details

AsmReferenceResolver

public AsmReferenceResolver(ClassNodeResolver resolver,
 CompilationUnit unit)

Creates an ASM reference resolver for a compilation unit.

Parameters:

resolver - the ClassNodeResolver used to resolve class names

unit - the CompilationUnit containing classes being compiled and metadata

Method Details

resolveClass

public ClassNode resolveClass(String className)

Resolves a fully qualified class name to a ClassNode. First checks classes being compiled in this unit, then consults the resolver for already-loaded classes.

Parameters:

className - the fully qualified class name

Returns:

the resolved ClassNode

Throws:

NoClassDefFoundError - if the class cannot be resolved

resolveClassNullable

public ClassNode resolveClassNullable(String className)

Attempts to resolve a fully qualified class name to a ClassNode, returning null if not found. First checks classes being compiled in this unit, then consults the resolver for already-loaded classes.

Parameters:

className - the fully qualified class name

Returns:

the resolved ClassNode, or null if not resolvable

resolveType

public ClassNode resolveType(org.objectweb.asm.Type type)

Resolves an ASM Type to a ClassNode, handling array types by wrapping element types.

Parameters:

type - the ASM type to resolve

Returns:

the corresponding ClassNode, with dimensions for array types

Throws:

NoClassDefFoundError - if an object type cannot be resolved

resolveJvmClass

public Class resolveJvmClass(String name)

Resolves a fully qualified class name to a runtime JVM Class object. Uses the compilation unit's class loader to load the class.

Parameters:

name - the fully qualified class name

Returns:

the loaded runtime Class

Throws:

GroovyBugError - if the class cannot be loaded (wrapped ClassNotFoundException)