CompileStack (Groovy 2.1.8)

java.lang.Object
- org.codehaus.groovy.classgen.asm.CompileStack

All Implemented Interfaces:

org.objectweb.asm.Opcodes
```
public class CompileStack
extends Object
implements org.objectweb.asm.Opcodes
```
This class is a helper for AsmClassGenerator. It manages different aspects of the code of a code block like handling labels, defining variables, and scopes. After a MethodNode is visited clear should be called, for initialization the method init should be used.
Some Notes:
- every push method will require a later pop call
- method parameters may define a category 2 variable, so don't ignore the type stored in the variable object
- the index of the variable may not be as assumed when the variable is a parameter of a method because the parameter may be used in a closure, so don't ignore the stored variable index
- the names of temporary variables can be ignored. The names are only used for debugging and do not conflict with each other or normal variables. For accessing, the index of the variable must be used.
- never mix temporary and normal variables by changes to this class. While the name is very important for a normal variable, it is only a helper construct for temporary variables. That means for example a name for a temporary variable can be used multiple times without conflict. So mixing them both may lead to the problem that a normal or temporary variable is hidden or even removed. That must not happen!
Author:

Jochen Theodorou

See Also:
AsmClassGenerator

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class CompileStack.BlockRecorder

protected static class CompileStack.LabelRange

Nested Classes
Modifier and Type	Class and Description
`static class`	`CompileStack.BlockRecorder`
`protected static class`	`CompileStack.LabelRange`

Field Summary
- 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, ASM4, 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, H_GETFIELD, H_GETSTATIC, H_INVOKEINTERFACE, H_INVOKESPECIAL, H_INVOKESTATIC, H_INVOKEVIRTUAL, H_NEWINVOKESPECIAL, H_PUTFIELD, H_PUTSTATIC, 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, 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

Constructors
Constructor and Description

CompileStack(WriterController wc)

Constructors
Constructor and Description
`CompileStack(WriterController wc)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addExceptionBlock(org.objectweb.asm.Label start, org.objectweb.asm.Label end, org.objectweb.asm.Label goal, String sig)`
`void`	`applyBlockRecorder()`
`void`	`applyFinallyBlocks(org.objectweb.asm.Label label, boolean isBreakLabel)`
`void`	`clear()` Clears the state of the class.
`boolean`	`containsVariable(String name)`
`org.objectweb.asm.Label`	`createLocalLabel(String name)` creates a new named label
`int`	`defineTemporaryVariable(String name, boolean store)` creates a temporary variable.
`int`	`defineTemporaryVariable(String name, ClassNode node, boolean store)` creates a temporary variable.
`int`	`defineTemporaryVariable(Variable var, boolean store)` creates a temporary variable.
`BytecodeVariable`	`defineVariable(Variable v, boolean initFromStack)` Defines a new Variable using an AST variable.
`BytecodeVariable`	`defineVariable(Variable v, ClassNode variableType, boolean initFromStack)`
`org.objectweb.asm.Label`	`getBreakLabel()`
`org.objectweb.asm.Label`	`getContinueLabel()`
`org.objectweb.asm.Label`	`getLabel(String name)` Returns the label for the given name
`org.objectweb.asm.Label`	`getNamedBreakLabel(String name)` Used for `break foo` inside a loop to end the execution of the marked loop.
`org.objectweb.asm.Label`	`getNamedContinueLabel(String name)` Used for `continue foo` inside a loop to continue the execution of the marked loop.
`VariableScope`	`getScope()`
`BytecodeVariable`	`getVariable(String variableName)`
`BytecodeVariable`	`getVariable(String variableName, boolean mustExist)` Returns a normal variable.
`boolean`	`hasBlockRecorder()`
`void`	`init(VariableScope el, Parameter[] parameters)` initializes this class for a MethodNode.
`boolean`	`isImplicitThis()`
`boolean`	`isInSpecialConstructorCall()`
`boolean`	`isLHS()`
`void`	`pop()`
`void`	`popBlockRecorderVisit(CompileStack.BlockRecorder finallyBlock)`
`void`	`popImplicitThis()`
`void`	`popLHS()`
`void`	`pushBlockRecorder(CompileStack.BlockRecorder recorder)`
`void`	`pushBlockRecorderVisit(CompileStack.BlockRecorder finallyBlock)`
`void`	`pushBooleanExpression()` because a boolean Expression may not be evaluated completely it is important to keep the registers clean
`void`	`pushImplicitThis(boolean implicitThis)`
`void`	`pushInSpecialConstructorCall()`
`void`	`pushLHS(boolean lhs)`
`void`	`pushLoop(String labelName)` Should be called when decending into a loop that does not define a scope.
`void`	`pushLoop(VariableScope el, String labelName)` Should be called when decending into a loop that defines also a scope.
`void`	`pushState()`
`org.objectweb.asm.Label`	`pushSwitch()` Creates a new break label and a element for the state stack so pop has to be called later
`void`	`pushVariableScope(VariableScope el)` Causes the statestack to add an element and sets the given scope as new current variable scope.
`void`	`removeVar(int tempIndex)`
`void`	`writeExceptionTable(CompileStack.BlockRecorder block, org.objectweb.asm.Label goal, String sig)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CompileStack
```
public CompileStack(WriterController wc)
```
- Method Detail
  - pushState
```
public void pushState()
```
  - getContinueLabel
```
public org.objectweb.asm.Label getContinueLabel()
```
  - getBreakLabel
```
public org.objectweb.asm.Label getBreakLabel()
```
  - removeVar
```
public void removeVar(int tempIndex)
```
  - pop
```
public void pop()
```
  - getScope
```
public VariableScope getScope()
```
  - defineTemporaryVariable
```
public int defineTemporaryVariable(Variable var,
                          boolean store)
```
    creates a temporary variable.
    
    Parameters:
    var - defines type and name
    store - defines if the toplevel argument of the stack should be stored
    
    Returns:
    the index used for this temporary variable
  - getVariable
```
public BytecodeVariable getVariable(String variableName)
```
  - getVariable
```
public BytecodeVariable getVariable(String variableName,
                           boolean mustExist)
```
    Returns a normal variable.
    If mustExist is true and the normal variable doesn't exist, then this method will throw a GroovyBugError. It is not the intention of this method to let this happen! And the exception should not be used for flow control - it is just acting as an assertion. If the exception is thrown then it indicates a bug in the class using CompileStack. This method can also not be used to return a temporary variable. Temporary variables are not normal variables.
    
    Parameters:
    variableName - name of the variable
    mustExist - throw exception if variable does not exist
    
    Returns:
    the normal variable or null if not found (and mustExist not true)
  - defineTemporaryVariable
```
public int defineTemporaryVariable(String name,
                          boolean store)
```
    creates a temporary variable.
    
    Parameters:
    name - defines type and name
    store - defines if the toplevel argument of the stack should be stored
    
    Returns:
    the index used for this temporary variable
  - defineTemporaryVariable
```
public int defineTemporaryVariable(String name,
                          ClassNode node,
                          boolean store)
```
    creates a temporary variable.
    
    Parameters:
    name - defines the name
    node - defines the node
    store - defines if the toplevel argument of the stack should be stored
    
    Returns:
    the index used for this temporary variable
  - clear
```
public void clear()
```
    Clears the state of the class. This method should be called after a MethodNode is visited. Note that a call to init will fail if clear is not called before
  - addExceptionBlock
```
public void addExceptionBlock(org.objectweb.asm.Label start,
                     org.objectweb.asm.Label end,
                     org.objectweb.asm.Label goal,
                     String sig)
```
  - init
```
public void init(VariableScope el,
        Parameter[] parameters)
```
    initializes this class for a MethodNode. This method will automatically define variables for the method parameters and will create references if needed. The created variables can be accessed by calling getVariable().
  - pushVariableScope
```
public void pushVariableScope(VariableScope el)
```
    Causes the statestack to add an element and sets the given scope as new current variable scope. Creates a element for the state stack so pop has to be called later
  - pushLoop
```
public void pushLoop(VariableScope el,
            String labelName)
```
    Should be called when decending into a loop that defines also a scope. Calls pushVariableScope and prepares labels for a loop structure. Creates a element for the state stack so pop has to be called later
  - pushLoop
```
public void pushLoop(String labelName)
```
    Should be called when decending into a loop that does not define a scope. Creates a element for the state stack so pop has to be called later
  - getNamedBreakLabel
```
public org.objectweb.asm.Label getNamedBreakLabel(String name)
```
    Used for break foo inside a loop to end the execution of the marked loop. This method will return the break label of the loop if there is one found for the name. If not, the current break label is returned.
  - getNamedContinueLabel
```
public org.objectweb.asm.Label getNamedContinueLabel(String name)
```
    Used for continue foo inside a loop to continue the execution of the marked loop. This method will return the break label of the loop if there is one found for the name. If not, getLabel is used.
  - pushSwitch
```
public org.objectweb.asm.Label pushSwitch()
```
    Creates a new break label and a element for the state stack so pop has to be called later
  - pushBooleanExpression
```
public void pushBooleanExpression()
```
    because a boolean Expression may not be evaluated completely it is important to keep the registers clean
  - defineVariable
```
public BytecodeVariable defineVariable(Variable v,
                              boolean initFromStack)
```
    Defines a new Variable using an AST variable.
    
    Parameters:
    initFromStack - if true the last element of the stack will be used to initialize the new variable. If false null will be used.
  - defineVariable
```
public BytecodeVariable defineVariable(Variable v,
                              ClassNode variableType,
                              boolean initFromStack)
```
  - containsVariable
```
public boolean containsVariable(String name)
```
    Parameters:
    name - the name of the variable of interest
    
    Returns:
    true if a variable is already defined
  - getLabel
```
public org.objectweb.asm.Label getLabel(String name)
```
    Returns the label for the given name
  - createLocalLabel
```
public org.objectweb.asm.Label createLocalLabel(String name)
```
    creates a new named label
  - applyFinallyBlocks
```
public void applyFinallyBlocks(org.objectweb.asm.Label label,
                      boolean isBreakLabel)
```
  - applyBlockRecorder
```
public void applyBlockRecorder()
```
  - hasBlockRecorder
```
public boolean hasBlockRecorder()
```
  - pushBlockRecorder
```
public void pushBlockRecorder(CompileStack.BlockRecorder recorder)
```
  - pushBlockRecorderVisit
```
public void pushBlockRecorderVisit(CompileStack.BlockRecorder finallyBlock)
```
  - popBlockRecorderVisit
```
public void popBlockRecorderVisit(CompileStack.BlockRecorder finallyBlock)
```
  - writeExceptionTable
```
public void writeExceptionTable(CompileStack.BlockRecorder block,
                       org.objectweb.asm.Label goal,
                       String sig)
```
  - isLHS
```
public boolean isLHS()
```
  - pushLHS
```
public void pushLHS(boolean lhs)
```
  - popLHS
```
public void popLHS()
```
  - pushImplicitThis
```
public void pushImplicitThis(boolean implicitThis)
```
  - isImplicitThis
```
public boolean isImplicitThis()
```
  - popImplicitThis
```
public void popImplicitThis()
```
  - isInSpecialConstructorCall
```
public boolean isInSpecialConstructorCall()
```
  - pushInSpecialConstructorCall
```
public void pushInSpecialConstructorCall()
```

Class CompileStack

Nested Class Summary

Field Summary

Fields inherited from interface org.objectweb.asm.Opcodes

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CompileStack

Method Detail

pushState

getContinueLabel

getBreakLabel

removeVar

pop

getScope

defineTemporaryVariable

getVariable

getVariable

defineTemporaryVariable

defineTemporaryVariable

clear

addExceptionBlock

init

pushVariableScope

pushLoop

pushLoop

getNamedBreakLabel

getNamedContinueLabel

pushSwitch

pushBooleanExpression

defineVariable

defineVariable

containsVariable

getLabel

createLocalLabel

applyFinallyBlocks

applyBlockRecorder

hasBlockRecorder

pushBlockRecorder

pushBlockRecorderVisit

popBlockRecorderVisit

writeExceptionTable

isLHS

pushLHS

popLHS

pushImplicitThis

isImplicitThis

popImplicitThis

isInSpecialConstructorCall

pushInSpecialConstructorCall