org.objectweb.asm.commons
Class JSRInlinerAdapter

java.lang.Object
  org.objectweb.asm.tree.MemberNode
      org.objectweb.asm.tree.MethodNode
          org.objectweb.asm.commons.JSRInlinerAdapter

All Implemented Interfaces:

MethodVisitor, Opcodes

public class JSRInlinerAdapter
extends MethodNode
implements Opcodes

A MethodAdapter that removes JSR instructions and inlines the referenced subroutines. Explanation of how it works TODO

Author:

Niko Matsakis

Nested Class Summary

private class	JSRInlinerAdapter.Instantiation A class that represents an instantiation of a subroutine.
protected static class	JSRInlinerAdapter.Subroutine

Field Summary

private java.util.BitSet	dualCitizens This BitSet contains the index of every instruction that belongs to more than one subroutine.
private static boolean	LOGGING
private JSRInlinerAdapter.Subroutine	mainSubroutine This subroutine instance denotes the line of execution that is not contained within any subroutine; i.e., the "subroutine" that is executing when a method first begins.
private MethodVisitor	mv The visitor to which we will emit a translation of this method without internal subroutines.
private java.util.Map	subroutineHeads For each label that is jumped to by a JSR, we create a Subroutine instance.

Fields inherited from class org.objectweb.asm.tree.MethodNode

access, annotationDefault, desc, exceptions, instructions, invisibleParameterAnnotations, localVariables, maxLocals, maxStack, name, signature, tryCatchBlocks, visibleParameterAnnotations

Fields inherited from class org.objectweb.asm.tree.MemberNode

attrs, invisibleAnnotations, visibleAnnotations

Fields inherited from interface org.objectweb.asm.Opcodes

AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DOUBLE, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F_APPEND, F_CHOP, F_FULL, F_NEW, F_SAME, F_SAME1, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FLOAT, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INTEGER, INVOKEDYNAMIC, INVOKEDYNAMIC_OWNER, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LONG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, NULL, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7

Constructor Summary

JSRInlinerAdapter(MethodVisitor mv, int access, java.lang.String name, java.lang.String desc, java.lang.String signature, java.lang.String[] exceptions)
Creates a new JSRInliner.

Method Summary

private void	emitCode() Creates the new instructions, inlining each instantiation of each subroutine until the code is fully elaborated.
private void	emitSubroutine(JSRInlinerAdapter.Instantiation instant, java.util.List worklist, InsnList newInstructions, java.util.List newTryCatchBlocks, java.util.List newLocalVariables) Emits one instantiation of one subroutine, specified by instant.
private static void	log(java.lang.String str)
private void	markSubroutines() Walks the method and determines which internal subroutine(s), if any, each instruction is a method of.
private void	markSubroutineWalk(JSRInlinerAdapter.Subroutine sub, int index, java.util.BitSet anyvisited) Performs a depth first search walking the normal byte code path starting at index, and adding each instruction encountered into the subroutine sub.
private void	markSubroutineWalkDFS(JSRInlinerAdapter.Subroutine sub, int index, java.util.BitSet anyvisited) Performs a simple DFS of the instructions, assigning each to the subroutine sub.
void	visitEnd() If any JSRs were seen, triggers the inlining process.
void	visitJumpInsn(int opcode, Label lbl) Detects a JSR instruction and sets a flag to indicate we will need to do inlining.

Methods inherited from class org.objectweb.asm.tree.MethodNode

accept, accept, getLabelNode, visitAnnotationDefault, visitCode, visitFieldInsn, visitFrame, visitIincInsn, visitInsn, visitIntInsn, visitLabel, visitLdcInsn, visitLineNumber, visitLocalVariable, visitLookupSwitchInsn, visitMaxs, visitMethodInsn, visitMultiANewArrayInsn, visitParameterAnnotation, visitTableSwitchInsn, visitTryCatchBlock, visitTypeInsn, visitVarInsn

Methods inherited from class org.objectweb.asm.tree.MemberNode

visitAnnotation, visitAttribute

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.objectweb.asm.MethodVisitor

visitAnnotation, visitAttribute

Field Detail

LOGGING

private static final boolean LOGGING

See Also:

Constant Field Values

mv

private final MethodVisitor mv

The visitor to which we will emit a translation of this method without internal subroutines.

subroutineHeads

private final java.util.Map subroutineHeads

For each label that is jumped to by a JSR, we create a Subroutine instance. Map is the generic type.

mainSubroutine

private final JSRInlinerAdapter.Subroutine mainSubroutine

This subroutine instance denotes the line of execution that is not contained within any subroutine; i.e., the "subroutine" that is executing when a method first begins.

dualCitizens

private final java.util.BitSet dualCitizens

This BitSet contains the index of every instruction that belongs to more than one subroutine. This should not happen often.

Constructor Detail

JSRInlinerAdapter

public JSRInlinerAdapter(MethodVisitor mv,
                         int access,
                         java.lang.String name,
                         java.lang.String desc,
                         java.lang.String signature,
                         java.lang.String[] exceptions)

Creates a new JSRInliner.

Parameters:

mv - the MethodVisitor to send the resulting inlined method code to (use null for none).

access - the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.

name - the method's name.

desc - the method's descriptor (see Type).

signature - the method's signature. May be null.

exceptions - the internal names of the method's exception classes (see getInternalName). May be null.

Method Detail

visitJumpInsn

public void visitJumpInsn(int opcode,
                          Label lbl)

Detects a JSR instruction and sets a flag to indicate we will need to do inlining.

Specified by:

visitJumpInsn in interface MethodVisitor

Overrides:

visitJumpInsn in class MethodNode

Parameters:

opcode - the opcode of the type instruction to be visited. This opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.

lbl - the operand of the instruction to be visited. This operand is a label that designates the instruction to which the jump instruction may jump.

visitEnd

public void visitEnd()

If any JSRs were seen, triggers the inlining process. Otherwise, forwards the byte codes untouched.

Specified by:

visitEnd in interface MethodVisitor

Overrides:

visitEnd in class MemberNode

markSubroutines

private void markSubroutines()

Walks the method and determines which internal subroutine(s), if any, each instruction is a method of.

markSubroutineWalk

private void markSubroutineWalk(JSRInlinerAdapter.Subroutine sub,
                                int index,
                                java.util.BitSet anyvisited)

Performs a depth first search walking the normal byte code path starting at index, and adding each instruction encountered into the subroutine sub. After this walk is complete, iterates over the exception handlers to ensure that we also include those byte codes which are reachable through an exception that may be thrown during the execution of the subroutine. Invoked from markSubroutines().

Parameters:

sub - the subroutine whose instructions must be computed.

index - an instruction of this subroutine.

anyvisited - indexes of the already visited instructions, i.e. marked as part of this subroutine or any previously computed subroutine.

markSubroutineWalkDFS

private void markSubroutineWalkDFS(JSRInlinerAdapter.Subroutine sub,
                                   int index,
                                   java.util.BitSet anyvisited)

Performs a simple DFS of the instructions, assigning each to the subroutine sub. Starts from index. Invoked only by markSubroutineWalk().

Parameters:

sub - the subroutine whose instructions must be computed.

index - an instruction of this subroutine.

anyvisited - indexes of the already visited instructions, i.e. marked as part of this subroutine or any previously computed subroutine.

emitCode

private void emitCode()

Creates the new instructions, inlining each instantiation of each subroutine until the code is fully elaborated.

emitSubroutine

private void emitSubroutine(JSRInlinerAdapter.Instantiation instant,
                            java.util.List worklist,
                            InsnList newInstructions,
                            java.util.List newTryCatchBlocks,
                            java.util.List newLocalVariables)

Emits one instantiation of one subroutine, specified by instant. May add new instantiations that are invoked by this one to the worklist parameter, and new try/catch blocks to newTryCatchBlocks.

Parameters:

instant - the instantiation that must be performed.

worklist - list of the instantiations that remain to be done.

newInstructions - the instruction list to which the instantiated code must be appended.

newTryCatchBlocks - the exception handler list to which the instantiated handlers must be appended.

log

private static void log(java.lang.String str)