org.apache.flex.compiler.internal.as.codegen

Class ControlFlowContextManager

java.lang.Object

org.apache.flex.compiler.internal.as.codegen.ControlFlowContextManager

public class ControlFlowContextManager
extends Object

The ControlFlowContextManager is the code generator's keeper of active control-flow contexts and the associated (implicit in the configuration of contexts) model of the scope stack. Control-flow contexts come in several varieties:

• Ordinary control-flow contexts, established by a labeled statement or a statement with break/continue semantics.
• Exception-handling contexts, established by try with a catch or finally.
• With statements.

These various types of context have few common elements, aside from participating in the model of control flow and the scope stack, so this class manages the active configuration of contexts and embodies the code generator's control-flow and scope stack model.

Field Summary

Fields

Modifier and Type	Field and Description
static int	CONTEXT_NOT_FOUND Manifest constant used by control-flow search routines for "not found"
static org.apache.flex.compiler.internal.as.codegen.ControlFlowContextManager.ControlFlowContextSearchCriteria	FIND_ALL_CONTEXTS Search criterion which finds all active contexts.

Method Summary

Methods

Modifier and Type	Method and Description
int	getFinallyAlternativesSize()
ExceptionHandlingContext	getFinallyContext()
InstructionList	getFinallyFailSignal()
InstructionList	getFinallySwitch()
InstructionList	getScopeStackReinit() Find all active scopes enclosing the currently active scope, and synthesize an instruction fragment to re-initialize the scope stack.
void	startLabeledStatementControlFlowContext(LabeledStatementNode labeledStatement) Called by a reduction's Prologue section to establish an active LabeledStatementControlFlowContext.
void	startLoopControlFlowContext(IASNode loopContents) Called by a reduction's Prologue section to establish an active LoopControlFlowContext.
void	startSwitchContext(SwitchNode node) Called by a reduction's Prologue section to establish an active SwitchControlFlowContext.

Methods inherited from class java.lang.Object

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

Field Detail

FIND_ALL_CONTEXTS

public static final org.apache.flex.compiler.internal.as.codegen.ControlFlowContextManager.ControlFlowContextSearchCriteria FIND_ALL_CONTEXTS

Search criterion which finds all active contexts.

CONTEXT_NOT_FOUND

public static final int CONTEXT_NOT_FOUND

Manifest constant used by control-flow search routines for "not found"

See Also:

Constant Field Values

Method Detail

startLoopControlFlowContext

public void startLoopControlFlowContext(IASNode loopContents)

Called by a reduction's Prologue section to establish an active LoopControlFlowContext.

Parameters:

loopContents - The syntax tree node containing the contents of the body of the loop. This node is used to establish a new scope for labels referenced by goto statements.

startSwitchContext

public void startSwitchContext(SwitchNode node)

Called by a reduction's Prologue section to establish an active SwitchControlFlowContext.

Parameters:

node - The syntax tree node for the switch statement.

startLabeledStatementControlFlowContext

public void startLabeledStatementControlFlowContext(LabeledStatementNode labeledStatement)
                                             throws DuplicateLabelException

Called by a reduction's Prologue section to establish an active LabeledStatementControlFlowContext.

Parameters:

labeledStatement - The syntax tree node for the labeled statement.

Throws:

DuplicateLabelException

getFinallySwitch

public InstructionList getFinallySwitch()

Returns:

the computed GOTO that implements the "return" from a finally block.

getScopeStackReinit

public InstructionList getScopeStackReinit()

Find all active scopes enclosing the currently active scope, and synthesize an instruction fragment to re-initialize the scope stack.

Returns:

the instruction fragment that re-initializes the enclosing scopes on the scope stack.

getFinallyContext

public ExceptionHandlingContext getFinallyContext()

Returns:

the ExceptionHandlingContext on top of the stack.

getFinallyAlternativesSize

public int getFinallyAlternativesSize()

Returns:

the number of callers to a finally block.

getFinallyFailSignal

public InstructionList getFinallyFailSignal()

Returns:

a code fragment that sets up the "fail" finally return.