Package com.tonic.analysis.source.recovery

Class ExpressionRecoverer

java.lang.Object

com.tonic.analysis.source.recovery.ExpressionRecoverer

public class ExpressionRecoverer
extends Object

Converts SSA IR instructions to source Expression trees.

Constructor Summary

Constructors

Constructor	Description
ExpressionRecoverer(RecoveryContext context)	Creates a recoverer bound to a recovery context, with its own type recoverer.

Method Summary

Modifier and Type	Method	Description
boolean	inliningWouldReorderEffects(SSAValue value)	True when inlining a side-effecting definition at its use would move it past another side effect.
boolean	operandInlinesSideEffect(Value value)	True when recovering value as an operand would inline an allocation or call - a side effect that must not be duplicated by re-emitting the expression.
boolean	operandMayThrowInline(Value value)	True when recovering value as an operand would inline an operation that can throw at runtime.
Expression	recover(IRInstruction instr)	Recovers the source expression an instruction produces.
Expression	recoverConstant(Constant c, SourceType typeHint)	Recovers a constant as a literal, using the hint to tell an int apart from a boolean or char.
Expression	recoverOperand(Value value)	Recovers an operand with no type hint, so booleans are inferred from the value alone.
Expression	recoverOperand(Value value, SourceType typeHint)	Recovers an operand, using the hint to tell a boolean from an int constant.
boolean	renderingAtUseCrossesEffects(IRInstruction def, IRInstruction use)	The same-block effect scan of inliningWouldReorderEffects(com.tonic.analysis.ssa.value.SSAValue) without the single-use gate.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionRecoverer

public ExpressionRecoverer(RecoveryContext context)

Creates a recoverer bound to a recovery context, with its own type recoverer.

Parameters:

context - the per-method recovery state

Method Detail

recover

public Expression recover(IRInstruction instr)

Recovers the source expression an instruction produces.

Parameters:

instr - the instruction to translate

Returns:

the expression, or null when the instruction has no expression form

recoverOperand

public Expression recoverOperand(Value value)

Recovers an operand with no type hint, so booleans are inferred from the value alone.

Parameters:

value - the operand to translate

Returns:

the expression for the operand

recoverOperand

public Expression recoverOperand(Value value,
                                 SourceType typeHint)

Recovers an operand, using the hint to tell a boolean from an int constant.

Parameters:

value - the operand to translate

typeHint - the expected type, or null

Returns:

the expression for the operand

inliningWouldReorderEffects

public boolean inliningWouldReorderEffects(SSAValue value)

True when inlining a side-effecting definition at its use would move it past another side effect.

Parameters:

value - the candidate for inlining, may be null

Returns:

true if the value must take a name and stay where it is defined

renderingAtUseCrossesEffects

public boolean renderingAtUseCrossesEffects(IRInstruction def,
                                            IRInstruction use)

The same-block effect scan of inliningWouldReorderEffects(com.tonic.analysis.ssa.value.SSAValue) without the single-use gate.

Parameters:

def - the defining instruction

use - the instruction the value would be rendered at

Returns:

true if an unrelated effect sits between the two in the same block

operandInlinesSideEffect

public boolean operandInlinesSideEffect(Value value)

True when recovering value as an operand would inline an allocation or call - a side effect that must not be duplicated by re-emitting the expression.

Parameters:

value - the operand to inspect

Returns:

true if recovering it as an operand would inline an allocation or call

operandMayThrowInline

public boolean operandMayThrowInline(Value value)

True when recovering value as an operand would inline an operation that can throw at runtime.

Parameters:

value - the operand to inspect

Returns:

true if recovering it as an operand would inline an operation that can throw

recoverConstant

public Expression recoverConstant(Constant c,
                                  SourceType typeHint)

Recovers a constant as a literal, using the hint to tell an int apart from a boolean or char.

Parameters:

c - the constant to recover

typeHint - the expected source type, may be null

Returns:

the literal expression, or a null literal for an unrecognized constant