Package com.tonic.analysis.source.recovery

Class StatementRecoverer

java.lang.Object

com.tonic.analysis.source.recovery.StatementRecoverer

All Implemented Interfaces:

RegionRecoveryBridge

public class StatementRecoverer
extends Object
implements RegionRecoveryBridge

Recovers Statement AST nodes from IR blocks, offering each region to the reaching-condition structurer first and falling back to the legacy walk for shapes it declines.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StatementRecoverer.RetiredSchemaRecoveryException	Signals a region classification whose schema recoverer is retired and which no engine route owned.

Constructor Summary

Constructors

Constructor	Description
StatementRecoverer(ControlFlowContext context, StructuralAnalyzer analyzer, ExpressionRecoverer exprRecoverer)	Creates a recoverer and pre-declares the method parameters so stores to them recover as assignments rather than declarations.

Method Summary

Modifier and Type	Method	Description
boolean	conditionInlinesSideEffect(IRBlock block)	True when recovering block's branch condition would inline an allocation or call - a side effect a shared-tail guard must not duplicate by re-emitting the condition.
SwitchDescriptor	decodeSwitch(IRBlock switchBlock)	Decodes switchBlock into a structuring-ready SwitchDescriptor - selector, merge, ordered cases and labels - without recovering case bodies or marking any block, so the reaching-condition engine can structure the cases itself.
TryNodeDescriptor	decodeTryNode(IRBlock block, Set<IRBlock> regionStops)	Statically decodes the try starting at block into an opaque TryNodeDescriptor - the blocks the try/catch recovery will consume and the single join it continues at - without recovering or marking anything.
SourceType	getLocalSlotUnifiedType(String slotName)	Looks up the type unified across every value stored into a local slot.
boolean	guardAtomExceptionFree(IRBlock block)	True when recovering block's branch condition inlines no operation that can throw.
boolean	hasDroppedOperations(BlockStmt body)	Completeness invariant.
boolean	isDuplicationSafe(IRBlock block)	True when block may be duplicated - re-recovered once per reaching edge - without changing semantics or perturbing the round trip.
boolean	isRegionBlockProcessed(IRBlock block)	True once block has been emitted.
boolean	isRetiredHandlerBlock(IRBlock block)	Whether block is the entry of an exception handler the surrounding recovery has already consumed - a retired copy-side guard catch or a de-duplicated finally's scaffolding.
List<Statement>	lowerInductionPhiInitsOnEdge(IRBlock pred, IRBlock succ)	As lowerPhisOnEdge(com.tonic.analysis.ssa.cfg.IRBlock, com.tonic.analysis.ssa.cfg.IRBlock), but only for the loop's for-induction counter phis - the ones emitPhiDeclaration(com.tonic.analysis.ssa.ir.PhiInstruction, java.util.List<com.tonic.analysis.source.ast.stmt.Statement>, java.util.Set<java.lang.String>, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>) deliberately does not declare.
List<Statement>	lowerPhisOnEdge(IRBlock pred, IRBlock succ)	SSA destruction on a CFG edge.
void	markRegionBlockProcessed(IRBlock block, List<Statement> statements)	Records block's recovered statements and marks it emitted so nothing re-emits it.
List<Statement>	processedReturnStatements(IRBlock block)	The statements of a processed RETURN block, for idempotent re-emission - a trailing return two paths share is recovered once by the first path's pass.
List<Statement>	recoverBlockSequence(IRBlock startBlock, Set<IRBlock> stopBlocks)	Recovers the statements of one region as a hand-off, preserving the surrounding recovery's processed marks.
List<Statement>	recoverBoundaryTail(IRBlock tail)	Recovers a straight terminal tail (single-successor blocks chaining into a return/throw) as fresh statements, without marking the blocks processed.
Expression	recoverCondition(IRBlock block, boolean negate)	The branch condition of block, negated when negate is set.
boolean	recoveredTryTerminates(Statement recovered)	Whether a statement recovered by RegionRecoveryBridge.recoverTryNode(com.tonic.analysis.ssa.cfg.IRBlock, com.tonic.analysis.source.recovery.rcs.TryNodeDescriptor, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>) leaves no normal fall-through.
BlockStmt	recoverMethod()	Recovers the whole method body, routing through try-with-resources or general exception handling when the method declares handlers.
BlockStmt	recoverMethodAsDispatch()	Recovers the whole method as a structured dispatch loop.
List<Statement>	recoverSimpleBlock(IRBlock block)	The straight-line statements of block (its terminator branch is not emitted here).
List<Statement>	recoverSwitchHeaderStatements(IRBlock header)	The switch header's own statements for emission before the switch.
Statement	recoverTryNode(IRBlock block, TryNodeDescriptor node, Set<IRBlock> stopBlocks, Set<IRBlock> alreadyEmitted)	Recovers the try node starting at block as one statement via the host's try/catch machinery, marking its handler and blocks consumed.
List<Statement>	recoverUnconsumedForLoopInits(IRBlock header)	The still-unconsumed for-induction inits of header's preheader.
boolean	regionContainsUnprocessedHandler(Set<IRBlock> region)	True when some block in region starts an exception handler the surrounding recovery has not yet consumed - a nested try the engine must decline so the try/catch scaffolding recovers it.
void	setEnumClassPool(ClassPool pool)	Sets the pool enum constants resolve from for switches that dispatch on ordinal() directly.
List<Statement>	stackPhiCopiesOnEdge(IRBlock pred, IRBlock succ)	Copies for succ's operand-stack merge phis whose incoming on this edge no instruction in pred produces.
boolean	startsUnprocessedHandler(IRBlock block)	True when block starts the protected range of an exception handler no recovery has consumed.
boolean	tryCollapseTernaryDiamond(IRBlock branch)	Collapses a value-producing ternary diamond headed by branch to a cached ternary expression, returning true when it applies.
void	unrecoveredTryNode(IRBlock block)	Signals that the host's try recovery produced nothing for a try node the engine had decoded - a routing gap, since every region structures through the engine.

Methods inherited from class java.lang.Object

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

Constructor Detail

StatementRecoverer

public StatementRecoverer(ControlFlowContext context,
                          StructuralAnalyzer analyzer,
                          ExpressionRecoverer exprRecoverer)

Creates a recoverer and pre-declares the method parameters so stores to them recover as assignments rather than declarations.

Parameters:

context - the per-method recovery state

analyzer - supplies the structural analysis of the control flow

exprRecoverer - recovers the expressions inside the statements

Method Detail

setEnumClassPool

public void setEnumClassPool(ClassPool pool)

Sets the pool enum constants resolve from for switches that dispatch on ordinal() directly.

Parameters:

pool - the class pool, or null to resolve nothing

markRegionBlockProcessed

public void markRegionBlockProcessed(IRBlock block,
                                     List<Statement> statements)

Description copied from interface: RegionRecoveryBridge

Records block's recovered statements and marks it emitted so nothing re-emits it.

Specified by:

markRegionBlockProcessed in interface RegionRecoveryBridge

Parameters:

block - the block being consumed

statements - the statements recovered for it

processedReturnStatements

public List<Statement> processedReturnStatements(IRBlock block)

Description copied from interface: RegionRecoveryBridge

The statements of a processed RETURN block, for idempotent re-emission - a trailing return two paths share is recovered once by the first path's pass.

Specified by:

processedReturnStatements in interface RegionRecoveryBridge

Parameters:

block - the shared trailing block

Returns:

its recovered return statements, empty when it is not a bare processed return

isRegionBlockProcessed

public boolean isRegionBlockProcessed(IRBlock block)

Description copied from interface: RegionRecoveryBridge

True once block has been emitted.

Specified by:

isRegionBlockProcessed in interface RegionRecoveryBridge

Parameters:

block - the block to test

Returns:

true when it has already been emitted

tryCollapseTernaryDiamond

public boolean tryCollapseTernaryDiamond(IRBlock branch)

Description copied from interface: RegionRecoveryBridge

Collapses a value-producing ternary diamond headed by branch to a cached ternary expression, returning true when it applies.

Specified by:

tryCollapseTernaryDiamond in interface RegionRecoveryBridge

Parameters:

branch - the candidate diamond head

Returns:

true when the diamond was collapsed and its arms marked emitted

decodeSwitch

public SwitchDescriptor decodeSwitch(IRBlock switchBlock)

Description copied from interface: RegionRecoveryBridge

Decodes switchBlock into a structuring-ready SwitchDescriptor - selector, merge, ordered cases and labels - without recovering case bodies or marking any block, so the reaching-condition engine can structure the cases itself.

Specified by:

decodeSwitch in interface RegionRecoveryBridge

Parameters:

switchBlock - the block terminated by the switch

Returns:

the decoded descriptor, or null for a shape the engine does not own natively

recoverSwitchHeaderStatements

public List<Statement> recoverSwitchHeaderStatements(IRBlock header)

Description copied from interface: RegionRecoveryBridge

The switch header's own statements for emission before the switch.

Specified by:

recoverSwitchHeaderStatements in interface RegionRecoveryBridge

Parameters:

header - the switch header block

Returns:

the statements to emit before the switch

recoverMethod

public BlockStmt recoverMethod()

Recovers the whole method body, routing through try-with-resources or general exception handling when the method declares handlers.

Returns:

the recovered body, or an empty block when the method has no entry

getLocalSlotUnifiedType

public SourceType getLocalSlotUnifiedType(String slotName)

Looks up the type unified across every value stored into a local slot.

Parameters:

slotName - the recovered variable name of the slot

Returns:

the unified type, or null if none was computed for the slot

recoverBlockSequence

public List<Statement> recoverBlockSequence(IRBlock startBlock,
                                            Set<IRBlock> stopBlocks)

Recovers the statements of one region as a hand-off, preserving the surrounding recovery's processed marks.

Parameters:

startBlock - the block the region starts at

stopBlocks - blocks that bound the region and are not recovered into it

Returns:

the recovered statements

startsUnprocessedHandler

public boolean startsUnprocessedHandler(IRBlock block)

Description copied from interface: RegionRecoveryBridge

True when block starts the protected range of an exception handler no recovery has consumed.

Specified by:

startsUnprocessedHandler in interface RegionRecoveryBridge

Parameters:

block - the candidate protected-range start

Returns:

true when an unconsumed handler protects a range starting there

isRetiredHandlerBlock

public boolean isRetiredHandlerBlock(IRBlock block)

Description copied from interface: RegionRecoveryBridge

Whether block is the entry of an exception handler the surrounding recovery has already consumed - a retired copy-side guard catch or a de-duplicated finally's scaffolding.

Specified by:

isRetiredHandlerBlock in interface RegionRecoveryBridge

Parameters:

block - the candidate handler entry

Returns:

true when it is a retired handler entry

decodeTryNode

public TryNodeDescriptor decodeTryNode(IRBlock block,
                                       Set<IRBlock> regionStops)

Description copied from interface: RegionRecoveryBridge

Statically decodes the try starting at block into an opaque TryNodeDescriptor - the blocks the try/catch recovery will consume and the single join it continues at - without recovering or marking anything.

Specified by:

decodeTryNode in interface RegionRecoveryBridge

Parameters:

block - the candidate try entry

regionStops - blocks that bound the enclosing region's walk

Returns:

the decoded node, or null for a shape the node model does not own

recoverBoundaryTail

public List<Statement> recoverBoundaryTail(IRBlock tail)

Description copied from interface: RegionRecoveryBridge

Recovers a straight terminal tail (single-successor blocks chaining into a return/throw) as fresh statements, without marking the blocks processed.

Specified by:

recoverBoundaryTail in interface RegionRecoveryBridge

Parameters:

tail - the first block of the candidate tail chain

Returns:

the tail's statements, or null when the shape is not a straight terminal tail

recoverTryNode

public Statement recoverTryNode(IRBlock block,
                                TryNodeDescriptor node,
                                Set<IRBlock> stopBlocks,
                                Set<IRBlock> alreadyEmitted)

Description copied from interface: RegionRecoveryBridge

Recovers the try node starting at block as one statement via the host's try/catch machinery, marking its handler and blocks consumed.

Specified by:

recoverTryNode in interface RegionRecoveryBridge

Parameters:

block - the try entry

node - the descriptor decoded by RegionRecoveryBridge.decodeTryNode(com.tonic.analysis.ssa.cfg.IRBlock, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>)

stopBlocks - blocks the try's walk must not cross into

alreadyEmitted - region blocks recovered before the node

Returns:

the try statement, or null when the shape cannot be recovered

recoveredTryTerminates

public boolean recoveredTryTerminates(Statement recovered)

Description copied from interface: RegionRecoveryBridge

Whether a statement recovered by RegionRecoveryBridge.recoverTryNode(com.tonic.analysis.ssa.cfg.IRBlock, com.tonic.analysis.source.recovery.rcs.TryNodeDescriptor, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>) leaves no normal fall-through.

Specified by:

recoveredTryTerminates in interface RegionRecoveryBridge

Parameters:

recovered - a statement produced by RegionRecoveryBridge.recoverTryNode(com.tonic.analysis.ssa.cfg.IRBlock, com.tonic.analysis.source.recovery.rcs.TryNodeDescriptor, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>)

Returns:

true when every path out of it returns or throws

unrecoveredTryNode

public void unrecoveredTryNode(IRBlock block)

Description copied from interface: RegionRecoveryBridge

Signals that the host's try recovery produced nothing for a try node the engine had decoded - a routing gap, since every region structures through the engine.

Specified by:

unrecoveredTryNode in interface RegionRecoveryBridge

Parameters:

block - the try entry whose recovery produced nothing

recoverSimpleBlock

public List<Statement> recoverSimpleBlock(IRBlock block)

Description copied from interface: RegionRecoveryBridge

The straight-line statements of block (its terminator branch is not emitted here).

Specified by:

recoverSimpleBlock in interface RegionRecoveryBridge

Parameters:

block - the block to recover

Returns:

its straight-line statements

hasDroppedOperations

public boolean hasDroppedOperations(BlockStmt body)

Completeness invariant.

Parameters:

body - the recovered method body to audit

Returns:

true if a reachable call is missing from the body

recoverMethodAsDispatch

public BlockStmt recoverMethodAsDispatch()

Recovers the whole method as a structured dispatch loop.

Returns:

the method body as a dispatch loop, or an empty block when the method has no entry

lowerPhisOnEdge

public List<Statement> lowerPhisOnEdge(IRBlock pred,
                                       IRBlock succ)

SSA destruction on a CFG edge.

Specified by:

lowerPhisOnEdge in interface RegionRecoveryBridge

Parameters:

pred - the source block of the edge

succ - the target block whose phis are lowered

Returns:

the copies for that edge

lowerInductionPhiInitsOnEdge

public List<Statement> lowerInductionPhiInitsOnEdge(IRBlock pred,
                                                    IRBlock succ)

As lowerPhisOnEdge(com.tonic.analysis.ssa.cfg.IRBlock, com.tonic.analysis.ssa.cfg.IRBlock), but only for the loop's for-induction counter phis - the ones emitPhiDeclaration(com.tonic.analysis.ssa.ir.PhiInstruction, java.util.List<com.tonic.analysis.source.ast.stmt.Statement>, java.util.Set<java.lang.String>, java.util.Set<com.tonic.analysis.ssa.cfg.IRBlock>) deliberately does not declare.

Specified by:

lowerInductionPhiInitsOnEdge in interface RegionRecoveryBridge

recoverUnconsumedForLoopInits

public List<Statement> recoverUnconsumedForLoopInits(IRBlock header)

Description copied from interface: RegionRecoveryBridge

The still-unconsumed for-induction inits of header's preheader.

Specified by:

recoverUnconsumedForLoopInits in interface RegionRecoveryBridge

Parameters:

header - the loop header whose preheader holds the inits

Returns:

the init declarations, empty when none remain

stackPhiCopiesOnEdge

public List<Statement> stackPhiCopiesOnEdge(IRBlock pred,
                                            IRBlock succ)

Copies for succ's operand-stack merge phis whose incoming on this edge no instruction in pred produces.

Specified by:

stackPhiCopiesOnEdge in interface RegionRecoveryBridge

Parameters:

pred - the source block of the edge

succ - the merge block whose stack phis are lowered

Returns:

the copies that arm owes the merge, empty when the arm already produced them

recoverCondition

public Expression recoverCondition(IRBlock block,
                                   boolean negate)

Description copied from interface: RegionRecoveryBridge

The branch condition of block, negated when negate is set.

Specified by:

recoverCondition in interface RegionRecoveryBridge

Parameters:

block - the block terminated by the branch

negate - whether to recover the complement

Returns:

the condition expression

conditionInlinesSideEffect

public boolean conditionInlinesSideEffect(IRBlock block)

Description copied from interface: RegionRecoveryBridge

True when recovering block's branch condition would inline an allocation or call - a side effect a shared-tail guard must not duplicate by re-emitting the condition.

Specified by:

conditionInlinesSideEffect in interface RegionRecoveryBridge

Parameters:

block - the block whose branch condition is inspected

Returns:

true when re-emitting the condition would repeat a side effect

guardAtomExceptionFree

public boolean guardAtomExceptionFree(IRBlock block)

Description copied from interface: RegionRecoveryBridge

True when recovering block's branch condition inlines no operation that can throw.

Specified by:

guardAtomExceptionFree in interface RegionRecoveryBridge

Parameters:

block - the block whose branch condition is inspected

Returns:

true when the condition inlines nothing that can throw

isDuplicationSafe

public boolean isDuplicationSafe(IRBlock block)

Description copied from interface: RegionRecoveryBridge

True when block may be duplicated - re-recovered once per reaching edge - without changing semantics or perturbing the round trip.

Specified by:

isDuplicationSafe in interface RegionRecoveryBridge

Parameters:

block - the block a region would re-recover per reaching edge

Returns:

true when duplicating it is safe

regionContainsUnprocessedHandler

public boolean regionContainsUnprocessedHandler(Set<IRBlock> region)

Description copied from interface: RegionRecoveryBridge

True when some block in region starts an exception handler the surrounding recovery has not yet consumed - a nested try the engine must decline so the try/catch scaffolding recovers it.

Specified by:

regionContainsUnprocessedHandler in interface RegionRecoveryBridge

Parameters:

region - the blocks under consideration

Returns:

true when one of them starts an unconsumed handler