org.apache.drill.exec.compile

Class AsmUtil

java.lang.Object

org.apache.drill.exec.compile.AsmUtil

public class AsmUtil
extends Object

Utilities commonly used with ASM.

There are several class verification utilities which use CheckClassAdapter (DrillCheckClassAdapter) to ensure classes are well-formed; these are packaged as boolean functions so that they can be used in assertions.

Method Summary

Modifier and Type	Method and Description
static org.objectweb.asm.tree.ClassNode	classFromBytes(byte[] classBytes, int asmReaderFlags) Create a ClassNode from bytecode.
static boolean	isClassBytesOk(org.slf4j.Logger logger, String logTag, byte[] classBytes) Check to see if a class is well-formed.
static boolean	isClassOk(org.slf4j.Logger logger, String logTag, org.objectweb.asm.tree.ClassNode classNode) Check to see if a class is well-formed.
static boolean	isXadd(int opcode) Determine if the given opcode is an ADD of some kind (xADD).
static boolean	isXconst(int opcode) Determine if the given opcode is a load of a constant (xCONST_y).
static void	logClass(org.slf4j.Logger logger, String logTag, org.objectweb.asm.tree.ClassNode classNode) Write a class to the log.
static void	logClassFromBytes(org.slf4j.Logger logger, String logTag, byte[] classBytes) Write a class to the log.

Methods inherited from class java.lang.Object

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

Method Detail

isClassOk

public static boolean isClassOk(org.slf4j.Logger logger,
                                String logTag,
                                org.objectweb.asm.tree.ClassNode classNode)

Check to see if a class is well-formed.

Parameters:

logger - the logger to write to if a problem is found

logTag - a tag to print to the log if a problem is found

classNode - the class to check

Returns:

true if the class is ok, false otherwise

isClassBytesOk

public static boolean isClassBytesOk(org.slf4j.Logger logger,
                                     String logTag,
                                     byte[] classBytes)

Check to see if a class is well-formed.

Parameters:

logger - the logger to write to if a problem is found

logTag - a tag to print to the log if a problem is found

classBytes - the bytecode of the class to check

Returns:

true if the class is ok, false otherwise

classFromBytes

public static org.objectweb.asm.tree.ClassNode classFromBytes(byte[] classBytes,
                                                              int asmReaderFlags)

Create a ClassNode from bytecode.

Parameters:

classBytes - the bytecode

asmReaderFlags - flags for ASM; see ClassReader.accept(org.objectweb.asm.ClassVisitor, int)

Returns:

the ClassNode

logClass

public static void logClass(org.slf4j.Logger logger,
                            String logTag,
                            org.objectweb.asm.tree.ClassNode classNode)

Write a class to the log.

Writes at level TRACE.

Parameters:

logger - the logger to write to

logTag - a tag to print to the log

classNode - the class

logClassFromBytes

public static void logClassFromBytes(org.slf4j.Logger logger,
                                     String logTag,
                                     byte[] classBytes)

Write a class to the log.

Writes at level DEBUG.

Parameters:

logTag - a tag to print to the log

classBytes - the class' bytecode

logger - the logger to write to

isXconst

public static boolean isXconst(int opcode)

Determine if the given opcode is a load of a constant (xCONST_y).

Parameters:

opcode - the opcode

Returns:

true if the opcode is one of the constant loading ones, false otherwise

isXadd

public static boolean isXadd(int opcode)

Determine if the given opcode is an ADD of some kind (xADD).

Parameters:

opcode - the opcode

Returns:

true if the opcode is one of the ADDs, false otherwise