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/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.lookup.*;
public class TryStatement extends SubRoutineStatement {
private final static char[] SECRET_RETURN_ADDRESS_NAME = " returnAddress".toCharArray(); //$NON-NLS-1$
private final static char[] SECRET_ANY_HANDLER_NAME = " anyExceptionHandler".toCharArray(); //$NON-NLS-1$
private final static char[] SECRET_RETURN_VALUE_NAME = " returnValue".toCharArray(); //$NON-NLS-1$
public Block tryBlock;
public Block[] catchBlocks;
public Argument[] catchArguments;
// should rename into subRoutineComplete to be set to false by default
public Block finallyBlock;
BlockScope scope;
public UnconditionalFlowInfo subRoutineInits;
ReferenceBinding[] caughtExceptionTypes;
boolean[] catchExits;
BranchLabel subRoutineStartLabel;
public LocalVariableBinding anyExceptionVariable,
returnAddressVariable,
secretReturnValue;
ExceptionLabel[] declaredExceptionLabels; // only set while generating code
// for inlining/optimizing JSR instructions
private Object[] reusableJSRTargets;
private BranchLabel[] reusableJSRSequenceStartLabels;
private int[] reusableJSRStateIndexes;
private int reusableJSRTargetsCount = 0;
private final static int NO_FINALLY = 0; // no finally block
private final static int FINALLY_SUBROUTINE = 1; // finally is generated as a subroutine (using jsr/ret bytecodes)
private final static int FINALLY_DOES_NOT_COMPLETE = 2; // non returning finally is optimized with only one instance of finally block
private final static int FINALLY_INLINE = 3; // finally block must be inlined since cannot use jsr/ret bytecodes >1.5
// for local variables table attributes
int mergedInitStateIndex = -1;
int preTryInitStateIndex = -1;
int naturalExitMergeInitStateIndex = -1;
int[] catchExitInitStateIndexes;
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
// Consider the try block and catch block so as to compute the intersection of initializations and
// the minimum exit relative depth amongst all of them. Then consider the subroutine, and append its
// initialization to the try/catch ones, if the subroutine completes normally. If the subroutine does not
// complete, then only keep this result for the rest of the analysis
// process the finally block (subroutine) - create a context for the subroutine
this.preTryInitStateIndex =
currentScope.methodScope().recordInitializationStates(flowInfo);
if (this.anyExceptionVariable != null) {
this.anyExceptionVariable.useFlag = LocalVariableBinding.USED;
}
if (this.returnAddressVariable != null) { // TODO (philippe) if subroutine is escaping, unused
this.returnAddressVariable.useFlag = LocalVariableBinding.USED;
}
if (this.subRoutineStartLabel == null) {
// no finally block -- this is a simplified copy of the else part
// process the try block in a context handling the local exceptions.
ExceptionHandlingFlowContext handlingContext =
new ExceptionHandlingFlowContext(
flowContext,
this,
this.caughtExceptionTypes,
null,
this.scope,
flowInfo.unconditionalInits());
handlingContext.initsOnFinally =
new NullInfoRegistry(flowInfo.unconditionalInits());
// only try blocks initialize that member - may consider creating a
// separate class if needed
FlowInfo tryInfo;
if (this.tryBlock.isEmptyBlock()) {
tryInfo = flowInfo;
} else {
tryInfo = this.tryBlock.analyseCode(currentScope, handlingContext, flowInfo.copy());
if ((tryInfo.tagBits & FlowInfo.UNREACHABLE) != 0)
this.bits |= ASTNode.IsTryBlockExiting;
}
// check unreachable catch blocks
handlingContext.complainIfUnusedExceptionHandlers(this.scope, this);
// process the catch blocks - computing the minimal exit depth amongst try/catch
if (this.catchArguments != null) {
int catchCount;
this.catchExits = new boolean[catchCount = this.catchBlocks.length];
this.catchExitInitStateIndexes = new int[catchCount];
for (int i = 0; i < catchCount; i++) {
// keep track of the inits that could potentially have led to this exception handler (for final assignments diagnosis)
FlowInfo catchInfo;
if (this.caughtExceptionTypes[i].isUncheckedException(true)) {
catchInfo =
handlingContext.initsOnFinally.mitigateNullInfoOf(
flowInfo.unconditionalCopy().
addPotentialInitializationsFrom(
handlingContext.initsOnException(
this.caughtExceptionTypes[i])).
addPotentialInitializationsFrom(tryInfo).
addPotentialInitializationsFrom(
handlingContext.initsOnReturn));
} else {
catchInfo =
flowInfo.unconditionalCopy().
addPotentialInitializationsFrom(
handlingContext.initsOnException(
this.caughtExceptionTypes[i]))
.addPotentialInitializationsFrom(
tryInfo.nullInfoLessUnconditionalCopy())
// remove null info to protect point of
// exception null info
.addPotentialInitializationsFrom(
handlingContext.initsOnReturn.
nullInfoLessUnconditionalCopy());
}
// catch var is always set
LocalVariableBinding catchArg = this.catchArguments[i].binding;
catchInfo.markAsDefinitelyAssigned(catchArg);
catchInfo.markAsDefinitelyNonNull(catchArg);
/*
"If we are about to consider an unchecked exception handler, potential inits may have occured inside
the try block that need to be detected , e.g.
try { x = 1; throwSomething();} catch(Exception e){ x = 2} "
"(uncheckedExceptionTypes notNil and: [uncheckedExceptionTypes at: index])
ifTrue: [catchInits addPotentialInitializationsFrom: tryInits]."
*/
if (this.tryBlock.statements == null) {
catchInfo.setReachMode(FlowInfo.UNREACHABLE);
}
catchInfo =
this.catchBlocks[i].analyseCode(
currentScope,
flowContext,
catchInfo);
this.catchExitInitStateIndexes[i] = currentScope.methodScope().recordInitializationStates(catchInfo);
this.catchExits[i] =
(catchInfo.tagBits & FlowInfo.UNREACHABLE) != 0;
tryInfo = tryInfo.mergedWith(catchInfo.unconditionalInits());
}
}
this.mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(tryInfo);
// chain up null info registry
if (flowContext.initsOnFinally != null) {
flowContext.initsOnFinally.add(handlingContext.initsOnFinally);
}
return tryInfo;
} else {
InsideSubRoutineFlowContext insideSubContext;
FinallyFlowContext finallyContext;
UnconditionalFlowInfo subInfo;
// analyse finally block first
insideSubContext = new InsideSubRoutineFlowContext(flowContext, this);
subInfo =
this.finallyBlock
.analyseCode(
currentScope,
finallyContext = new FinallyFlowContext(flowContext, this.finallyBlock),
flowInfo.nullInfoLessUnconditionalCopy())
.unconditionalInits();
if (subInfo == FlowInfo.DEAD_END) {
this.bits |= ASTNode.IsSubRoutineEscaping;
this.scope.problemReporter().finallyMustCompleteNormally(this.finallyBlock);
}
this.subRoutineInits = subInfo;
// process the try block in a context handling the local exceptions.
ExceptionHandlingFlowContext handlingContext =
new ExceptionHandlingFlowContext(
insideSubContext,
this,
this.caughtExceptionTypes,
null,
this.scope,
flowInfo.unconditionalInits());
handlingContext.initsOnFinally =
new NullInfoRegistry(flowInfo.unconditionalInits());
// only try blocks initialize that member - may consider creating a
// separate class if needed
FlowInfo tryInfo;
if (this.tryBlock.isEmptyBlock()) {
tryInfo = flowInfo;
} else {
tryInfo = this.tryBlock.analyseCode(currentScope, handlingContext, flowInfo.copy());
if ((tryInfo.tagBits & FlowInfo.UNREACHABLE) != 0)
this.bits |= ASTNode.IsTryBlockExiting;
}
// check unreachable catch blocks
handlingContext.complainIfUnusedExceptionHandlers(this.scope, this);
// process the catch blocks - computing the minimal exit depth amongst try/catch
if (this.catchArguments != null) {
int catchCount;
this.catchExits = new boolean[catchCount = this.catchBlocks.length];
this.catchExitInitStateIndexes = new int[catchCount];
for (int i = 0; i < catchCount; i++) {
// keep track of the inits that could potentially have led to this exception handler (for final assignments diagnosis)
FlowInfo catchInfo;
if (this.caughtExceptionTypes[i].isUncheckedException(true)) {
catchInfo =
handlingContext.initsOnFinally.mitigateNullInfoOf(
flowInfo.unconditionalCopy().
addPotentialInitializationsFrom(
handlingContext.initsOnException(
this.caughtExceptionTypes[i])).
addPotentialInitializationsFrom(tryInfo).
addPotentialInitializationsFrom(
handlingContext.initsOnReturn));
}else {
catchInfo =
flowInfo.unconditionalCopy()
.addPotentialInitializationsFrom(
handlingContext.initsOnException(
this.caughtExceptionTypes[i]))
.addPotentialInitializationsFrom(
tryInfo.nullInfoLessUnconditionalCopy())
// remove null info to protect point of
// exception null info
.addPotentialInitializationsFrom(
handlingContext.initsOnReturn.
nullInfoLessUnconditionalCopy());
}
// catch var is always set
LocalVariableBinding catchArg = this.catchArguments[i].binding;
catchInfo.markAsDefinitelyAssigned(catchArg);
catchInfo.markAsDefinitelyNonNull(catchArg);
/*
"If we are about to consider an unchecked exception handler, potential inits may have occured inside
the try block that need to be detected , e.g.
try { x = 1; throwSomething();} catch(Exception e){ x = 2} "
"(uncheckedExceptionTypes notNil and: [uncheckedExceptionTypes at: index])
ifTrue: [catchInits addPotentialInitializationsFrom: tryInits]."
*/
if (this.tryBlock.statements == null) {
catchInfo.setReachMode(FlowInfo.UNREACHABLE);
}
catchInfo =
this.catchBlocks[i].analyseCode(
currentScope,
insideSubContext,
catchInfo);
this.catchExitInitStateIndexes[i] = currentScope.methodScope().recordInitializationStates(catchInfo);
this.catchExits[i] =
(catchInfo.tagBits & FlowInfo.UNREACHABLE) != 0;
tryInfo = tryInfo.mergedWith(catchInfo.unconditionalInits());
}
}
// we also need to check potential multiple assignments of final variables inside the finally block
// need to include potential inits from returns inside the try/catch parts - 1GK2AOF
finallyContext.complainOnDeferredChecks(
handlingContext.initsOnFinally.mitigateNullInfoOf(
(tryInfo.tagBits & FlowInfo.UNREACHABLE) == 0 ?
flowInfo.unconditionalCopy().
addPotentialInitializationsFrom(tryInfo).
// lighten the influence of the try block, which may have
// exited at any point
addPotentialInitializationsFrom(insideSubContext.initsOnReturn) :
insideSubContext.initsOnReturn),
currentScope);
// chain up null info registry
if (flowContext.initsOnFinally != null) {
flowContext.initsOnFinally.add(handlingContext.initsOnFinally);
}
this.naturalExitMergeInitStateIndex =
currentScope.methodScope().recordInitializationStates(tryInfo);
if (subInfo == FlowInfo.DEAD_END) {
this.mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(subInfo);
return subInfo;
} else {
FlowInfo mergedInfo = tryInfo.addInitializationsFrom(subInfo);
this.mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(mergedInfo);
return mergedInfo;
}
}
}
public ExceptionLabel enterAnyExceptionHandler(CodeStream codeStream) {
if (this.subRoutineStartLabel == null)
return null;
return super.enterAnyExceptionHandler(codeStream);
}
public void enterDeclaredExceptionHandlers(CodeStream codeStream) {
for (int i = 0, length = this.declaredExceptionLabels == null ? 0 : this.declaredExceptionLabels.length; i < length; i++) {
this.declaredExceptionLabels[i].placeStart();
}
}
public void exitAnyExceptionHandler() {
if (this.subRoutineStartLabel == null)
return;
super.exitAnyExceptionHandler();
}
public void exitDeclaredExceptionHandlers(CodeStream codeStream) {
for (int i = 0, length = this.declaredExceptionLabels == null ? 0 : this.declaredExceptionLabels.length; i < length; i++) {
this.declaredExceptionLabels[i].placeEnd();
}
}
private int finallyMode() {
if (this.subRoutineStartLabel == null) {
return NO_FINALLY;
} else if (isSubRoutineEscaping()) {
return FINALLY_DOES_NOT_COMPLETE;
} else if (this.scope.compilerOptions().inlineJsrBytecode) {
return FINALLY_INLINE;
} else {
return FINALLY_SUBROUTINE;
}
}
/**
* Try statement code generation with or without jsr bytecode use
* post 1.5 target level, cannot use jsr bytecode, must instead inline finally block
* returnAddress is only allocated if jsr is allowed
*/
public void generateCode(BlockScope currentScope, CodeStream codeStream) {
if ((this.bits & ASTNode.IsReachable) == 0) {
return;
}
boolean isStackMapFrameCodeStream = codeStream instanceof StackMapFrameCodeStream;
// in case the labels needs to be reinitialized
// when the code generation is restarted in wide mode
this.anyExceptionLabel = null;
this.reusableJSRTargets = null;
this.reusableJSRSequenceStartLabels = null;
this.reusableJSRTargetsCount = 0;
int pc = codeStream.position;
int finallyMode = finallyMode();
boolean requiresNaturalExit = false;
// preparing exception labels
int maxCatches = this.catchArguments == null ? 0 : this.catchArguments.length;
ExceptionLabel[] exceptionLabels;
if (maxCatches > 0) {
exceptionLabels = new ExceptionLabel[maxCatches];
for (int i = 0; i < maxCatches; i++) {
ExceptionLabel exceptionLabel = new ExceptionLabel(codeStream, this.catchArguments[i].binding.type);
exceptionLabel.placeStart();
exceptionLabels[i] = exceptionLabel;
}
} else {
exceptionLabels = null;
}
if (this.subRoutineStartLabel != null) {
this.subRoutineStartLabel.initialize(codeStream);
enterAnyExceptionHandler(codeStream);
}
// generate the try block
try {
this.declaredExceptionLabels = exceptionLabels;
this.tryBlock.generateCode(this.scope, codeStream);
} finally {
this.declaredExceptionLabels = null;
}
boolean tryBlockHasSomeCode = codeStream.position != pc;
// flag telling if some bytecodes were issued inside the try block
// place end positions of user-defined exception labels
if (tryBlockHasSomeCode) {
// natural exit may require subroutine invocation (if finally != null)
BranchLabel naturalExitLabel = new BranchLabel(codeStream);
BranchLabel postCatchesFinallyLabel = null;
for (int i = 0; i < maxCatches; i++) {
exceptionLabels[i].placeEnd();
}
if ((this.bits & ASTNode.IsTryBlockExiting) == 0) {
int position = codeStream.position;
switch(finallyMode) {
case FINALLY_SUBROUTINE :
case FINALLY_INLINE :
requiresNaturalExit = true;
if (this.naturalExitMergeInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
codeStream.goto_(naturalExitLabel);
break;
case NO_FINALLY :
if (this.naturalExitMergeInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
codeStream.goto_(naturalExitLabel);
break;
case FINALLY_DOES_NOT_COMPLETE :
codeStream.goto_(this.subRoutineStartLabel);
break;
}
codeStream.updateLastRecordedEndPC(this.tryBlock.scope, position);
//goto is tagged as part of the try block
}
/* generate sequence of handler, all starting by storing the TOS (exception
thrown) into their own catch variables, the one specified in the source
that must denote the handled exception.
*/
exitAnyExceptionHandler();
if (this.catchArguments != null) {
postCatchesFinallyLabel = new BranchLabel(codeStream);
for (int i = 0; i < maxCatches; i++) {
/*
* This should not happen. For consistency purpose, if the exception label is never used
* we also don't generate the corresponding catch block, otherwise we have some
* unreachable bytecodes
*/
if (exceptionLabels[i].count == 0) continue;
enterAnyExceptionHandler(codeStream);
// May loose some local variable initializations : affecting the local variable attributes
if (this.preTryInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.preTryInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.preTryInitStateIndex);
}
codeStream.pushExceptionOnStack(exceptionLabels[i].exceptionType);
exceptionLabels[i].place();
// optimizing the case where the exception variable is not actually used
LocalVariableBinding catchVar;
int varPC = codeStream.position;
if ((catchVar = this.catchArguments[i].binding).resolvedPosition != -1) {
codeStream.store(catchVar, false);
catchVar.recordInitializationStartPC(codeStream.position);
codeStream.addVisibleLocalVariable(catchVar);
} else {
codeStream.pop();
}
codeStream.recordPositionsFrom(varPC, this.catchArguments[i].sourceStart);
// Keep track of the pcs at diverging point for computing the local attribute
// since not passing the catchScope, the block generation will exitUserScope(catchScope)
this.catchBlocks[i].generateCode(this.scope, codeStream);
exitAnyExceptionHandler();
if (!this.catchExits[i]) {
switch(finallyMode) {
case FINALLY_INLINE :
// inlined finally here can see all merged variables
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).pushStateIndex(this.naturalExitMergeInitStateIndex);
}
if (this.catchExitInitStateIndexes[i] != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.catchExitInitStateIndexes[i]);
codeStream.addDefinitelyAssignedVariables(currentScope, this.catchExitInitStateIndexes[i]);
}
// entire sequence for finally is associated to finally block
this.finallyBlock.generateCode(this.scope, codeStream);
codeStream.goto_(postCatchesFinallyLabel);
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).popStateIndex();
}
break;
case FINALLY_SUBROUTINE :
requiresNaturalExit = true;
//$FALL-THROUGH$
case NO_FINALLY :
if (this.naturalExitMergeInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
codeStream.goto_(naturalExitLabel);
break;
case FINALLY_DOES_NOT_COMPLETE :
codeStream.goto_(this.subRoutineStartLabel);
break;
}
}
}
}
// extra handler for trailing natural exit (will be fixed up later on when natural exit is generated below)
ExceptionLabel naturalExitExceptionHandler = requiresNaturalExit && (finallyMode == FINALLY_SUBROUTINE)
? new ExceptionLabel(codeStream, null)
: null;
// addition of a special handler so as to ensure that any uncaught exception (or exception thrown
// inside catch blocks) will run the finally block
int finallySequenceStartPC = codeStream.position;
if (this.subRoutineStartLabel != null && this.anyExceptionLabel.count != 0) {
codeStream.pushExceptionOnStack(this.scope.getJavaLangThrowable());
if (this.preTryInitStateIndex != -1) {
// reset initialization state, as for a normal catch block
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.preTryInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.preTryInitStateIndex);
}
placeAllAnyExceptionHandler();
if (naturalExitExceptionHandler != null) naturalExitExceptionHandler.place();
switch(finallyMode) {
case FINALLY_SUBROUTINE :
// any exception handler
codeStream.store(this.anyExceptionVariable, false);
codeStream.jsr(this.subRoutineStartLabel);
codeStream.recordPositionsFrom(finallySequenceStartPC, this.finallyBlock.sourceStart);
int position = codeStream.position;
codeStream.throwAnyException(this.anyExceptionVariable);
codeStream.recordPositionsFrom(position, this.finallyBlock.sourceEnd);
// subroutine
this.subRoutineStartLabel.place();
codeStream.pushExceptionOnStack(this.scope.getJavaLangThrowable());
position = codeStream.position;
codeStream.store(this.returnAddressVariable, false);
codeStream.recordPositionsFrom(position, this.finallyBlock.sourceStart);
this.finallyBlock.generateCode(this.scope, codeStream);
position = codeStream.position;
codeStream.ret(this.returnAddressVariable.resolvedPosition);
codeStream.recordPositionsFrom(
position,
this.finallyBlock.sourceEnd);
// the ret bytecode is part of the subroutine
break;
case FINALLY_INLINE :
// any exception handler
codeStream.store(this.anyExceptionVariable, false);
codeStream.addVariable(this.anyExceptionVariable);
codeStream.recordPositionsFrom(finallySequenceStartPC, this.finallyBlock.sourceStart);
// subroutine
this.finallyBlock.generateCode(currentScope, codeStream);
position = codeStream.position;
codeStream.throwAnyException(this.anyExceptionVariable);
codeStream.removeVariable(this.anyExceptionVariable);
if (this.preTryInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.preTryInitStateIndex);
}
this.subRoutineStartLabel.place();
codeStream.recordPositionsFrom(position, this.finallyBlock.sourceEnd);
break;
case FINALLY_DOES_NOT_COMPLETE :
// any exception handler
codeStream.pop();
this.subRoutineStartLabel.place();
codeStream.recordPositionsFrom(finallySequenceStartPC, this.finallyBlock.sourceStart);
// subroutine
this.finallyBlock.generateCode(this.scope, codeStream);
break;
}
// will naturally fall into subsequent code after subroutine invocation
if (requiresNaturalExit) {
switch(finallyMode) {
case FINALLY_SUBROUTINE :
naturalExitLabel.place();
int position = codeStream.position;
naturalExitExceptionHandler.placeStart();
codeStream.jsr(this.subRoutineStartLabel);
naturalExitExceptionHandler.placeEnd();
codeStream.recordPositionsFrom(
position,
this.finallyBlock.sourceEnd);
break;
case FINALLY_INLINE :
// inlined finally here can see all merged variables
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).pushStateIndex(this.naturalExitMergeInitStateIndex);
}
if (this.naturalExitMergeInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
naturalExitLabel.place();
// entire sequence for finally is associated to finally block
this.finallyBlock.generateCode(this.scope, codeStream);
if (postCatchesFinallyLabel != null) {
position = codeStream.position;
// entire sequence for finally is associated to finally block
codeStream.goto_(postCatchesFinallyLabel);
codeStream.recordPositionsFrom(
position,
this.finallyBlock.sourceEnd);
}
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).popStateIndex();
}
break;
case FINALLY_DOES_NOT_COMPLETE :
break;
default :
naturalExitLabel.place();
break;
}
}
if (postCatchesFinallyLabel != null) {
postCatchesFinallyLabel.place();
}
} else {
// no subroutine, simply position end label (natural exit == end)
naturalExitLabel.place();
}
} else {
// try block had no effect, only generate the body of the finally block if any
if (this.subRoutineStartLabel != null) {
this.finallyBlock.generateCode(this.scope, codeStream);
}
}
// May loose some local variable initializations : affecting the local variable attributes
if (this.mergedInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex);
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
/**
* @see SubRoutineStatement#generateSubRoutineInvocation(BlockScope, CodeStream, Object, int, LocalVariableBinding)
*/
public boolean generateSubRoutineInvocation(BlockScope currentScope, CodeStream codeStream, Object targetLocation, int stateIndex, LocalVariableBinding secretLocal) {
boolean isStackMapFrameCodeStream = codeStream instanceof StackMapFrameCodeStream;
int finallyMode = finallyMode();
switch(finallyMode) {
case FINALLY_DOES_NOT_COMPLETE :
codeStream.goto_(this.subRoutineStartLabel);
return true;
case NO_FINALLY :
exitDeclaredExceptionHandlers(codeStream);
return false;
}
// optimize subroutine invocation sequences, using the targetLocation (if any)
if (targetLocation != null) {
boolean reuseTargetLocation = true;
if (this.reusableJSRTargetsCount > 0) {
nextReusableTarget: for (int i = 0, count = this.reusableJSRTargetsCount; i < count; i++) {
Object reusableJSRTarget = this.reusableJSRTargets[i];
differentTarget: {
if (targetLocation == reusableJSRTarget)
break differentTarget;
if (targetLocation instanceof Constant
&& reusableJSRTarget instanceof Constant
&& ((Constant)targetLocation).hasSameValue((Constant) reusableJSRTarget)) {
break differentTarget;
}
// cannot reuse current target
continue nextReusableTarget;
}
// current target has been used in the past, simply branch to its label
if ((this.reusableJSRStateIndexes[i] != stateIndex) && finallyMode == FINALLY_INLINE) {
reuseTargetLocation = false;
break nextReusableTarget;
} else {
codeStream.goto_(this.reusableJSRSequenceStartLabels[i]);
return true;
}
}
} else {
this.reusableJSRTargets = new Object[3];
this.reusableJSRSequenceStartLabels = new BranchLabel[3];
this.reusableJSRStateIndexes = new int[3];
}
if (reuseTargetLocation) {
if (this.reusableJSRTargetsCount == this.reusableJSRTargets.length) {
System.arraycopy(this.reusableJSRTargets, 0, this.reusableJSRTargets = new Object[2*this.reusableJSRTargetsCount], 0, this.reusableJSRTargetsCount);
System.arraycopy(this.reusableJSRSequenceStartLabels, 0, this.reusableJSRSequenceStartLabels = new BranchLabel[2*this.reusableJSRTargetsCount], 0, this.reusableJSRTargetsCount);
System.arraycopy(this.reusableJSRStateIndexes, 0, this.reusableJSRStateIndexes = new int[2*this.reusableJSRTargetsCount], 0, this.reusableJSRTargetsCount);
}
this.reusableJSRTargets[this.reusableJSRTargetsCount] = targetLocation;
BranchLabel reusableJSRSequenceStartLabel = new BranchLabel(codeStream);
reusableJSRSequenceStartLabel.place();
this.reusableJSRStateIndexes[this.reusableJSRTargetsCount] = stateIndex;
this.reusableJSRSequenceStartLabels[this.reusableJSRTargetsCount++] = reusableJSRSequenceStartLabel;
}
}
if (finallyMode == FINALLY_INLINE) {
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).pushStateIndex(stateIndex);
if (this.naturalExitMergeInitStateIndex != -1 || stateIndex != -1) {
// reset initialization state, as for a normal catch block
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
} else {
if (this.naturalExitMergeInitStateIndex != -1) {
// reset initialization state, as for a normal catch block
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.naturalExitMergeInitStateIndex);
}
}
if (secretLocal != null) {
codeStream.addVariable(secretLocal);
}
// cannot use jsr bytecode, then simply inline the subroutine
// inside try block, ensure to deactivate all catch block exception handlers while inlining finally block
exitAnyExceptionHandler();
exitDeclaredExceptionHandlers(codeStream);
this.finallyBlock.generateCode(currentScope, codeStream);
if (isStackMapFrameCodeStream) {
((StackMapFrameCodeStream) codeStream).popStateIndex();
}
} else {
// classic subroutine invocation, distinguish case of non-returning subroutine
codeStream.jsr(this.subRoutineStartLabel);
exitAnyExceptionHandler();
exitDeclaredExceptionHandlers(codeStream);
}
return false;
}
public boolean isSubRoutineEscaping() {
return (this.bits & ASTNode.IsSubRoutineEscaping) != 0;
}
public StringBuffer printStatement(int indent, StringBuffer output) {
printIndent(indent, output).append("try \n"); //$NON-NLS-1$
this.tryBlock.printStatement(indent + 1, output);
//catches
if (this.catchBlocks != null)
for (int i = 0; i < this.catchBlocks.length; i++) {
output.append('\n');
printIndent(indent, output).append("catch ("); //$NON-NLS-1$
this.catchArguments[i].print(0, output).append(") "); //$NON-NLS-1$
this.catchBlocks[i].printStatement(indent + 1, output);
}
//finally
if (this.finallyBlock != null) {
output.append('\n');
printIndent(indent, output).append("finally\n"); //$NON-NLS-1$
this.finallyBlock.printStatement(indent + 1, output);
}
return output;
}
public void resolve(BlockScope upperScope) {
// special scope for secret locals optimization.
this.scope = new BlockScope(upperScope);
BlockScope tryScope = new BlockScope(this.scope);
BlockScope finallyScope = null;
if (this.finallyBlock != null) {
if (this.finallyBlock.isEmptyBlock()) {
if ((this.finallyBlock.bits & ASTNode.UndocumentedEmptyBlock) != 0) {
this.scope.problemReporter().undocumentedEmptyBlock(this.finallyBlock.sourceStart, this.finallyBlock.sourceEnd);
}
} else {
finallyScope = new BlockScope(this.scope, false); // don't add it yet to parent scope
// provision for returning and forcing the finally block to run
MethodScope methodScope = this.scope.methodScope();
// the type does not matter as long as it is not a base type
if (!upperScope.compilerOptions().inlineJsrBytecode) {
this.returnAddressVariable =
new LocalVariableBinding(TryStatement.SECRET_RETURN_ADDRESS_NAME, upperScope.getJavaLangObject(), ClassFileConstants.AccDefault, false);
finallyScope.addLocalVariable(this.returnAddressVariable);
this.returnAddressVariable.setConstant(Constant.NotAConstant); // not inlinable
}
this.subRoutineStartLabel = new BranchLabel();
this.anyExceptionVariable =
new LocalVariableBinding(TryStatement.SECRET_ANY_HANDLER_NAME, this.scope.getJavaLangThrowable(), ClassFileConstants.AccDefault, false);
finallyScope.addLocalVariable(this.anyExceptionVariable);
this.anyExceptionVariable.setConstant(Constant.NotAConstant); // not inlinable
if (!methodScope.isInsideInitializer()) {
MethodBinding methodBinding =
((AbstractMethodDeclaration) methodScope.referenceContext).binding;
if (methodBinding != null) {
TypeBinding methodReturnType = methodBinding.returnType;
if (methodReturnType.id != TypeIds.T_void) {
this.secretReturnValue =
new LocalVariableBinding(
TryStatement.SECRET_RETURN_VALUE_NAME,
methodReturnType,
ClassFileConstants.AccDefault,
false);
finallyScope.addLocalVariable(this.secretReturnValue);
this.secretReturnValue.setConstant(Constant.NotAConstant); // not inlinable
}
}
}
this.finallyBlock.resolveUsing(finallyScope);
// force the finally scope to have variable positions shifted after its try scope and catch ones
finallyScope.shiftScopes = new BlockScope[this.catchArguments == null ? 1 : this.catchArguments.length+1];
finallyScope.shiftScopes[0] = tryScope;
}
}
this.tryBlock.resolveUsing(tryScope);
// arguments type are checked against JavaLangThrowable in resolveForCatch(..)
if (this.catchBlocks != null) {
int length = this.catchArguments.length;
TypeBinding[] argumentTypes = new TypeBinding[length];
boolean catchHasError = false;
for (int i = 0; i < length; i++) {
BlockScope catchScope = new BlockScope(this.scope);
if (finallyScope != null){
finallyScope.shiftScopes[i+1] = catchScope;
}
// side effect on catchScope in resolveForCatch(..)
if ((argumentTypes[i] = this.catchArguments[i].resolveForCatch(catchScope)) == null) {
catchHasError = true;
}
this.catchBlocks[i].resolveUsing(catchScope);
}
if (catchHasError) {
return;
}
// Verify that the catch clause are ordered in the right way:
// more specialized first.
this.caughtExceptionTypes = new ReferenceBinding[length];
for (int i = 0; i < length; i++) {
this.caughtExceptionTypes[i] = (ReferenceBinding) argumentTypes[i];
for (int j = 0; j < i; j++) {
if (this.caughtExceptionTypes[i].isCompatibleWith(argumentTypes[j])) {
this.scope.problemReporter().wrongSequenceOfExceptionTypesError(this, this.caughtExceptionTypes[i], i, argumentTypes[j]);
}
}
}
} else {
this.caughtExceptionTypes = new ReferenceBinding[0];
}
if (finallyScope != null){
// add finallyScope as last subscope, so it can be shifted behind try/catch subscopes.
// the shifting is necessary to achieve no overlay in between the finally scope and its
// sibling in term of local variable positions.
this.scope.addSubscope(finallyScope);
}
}
public void traverse(ASTVisitor visitor, BlockScope blockScope) {
if (visitor.visit(this, blockScope)) {
this.tryBlock.traverse(visitor, this.scope);
if (this.catchArguments != null) {
for (int i = 0, max = this.catchBlocks.length; i < max; i++) {
this.catchArguments[i].traverse(visitor, this.scope);
this.catchBlocks[i].traverse(visitor, this.scope);
}
}
if (this.finallyBlock != null)
this.finallyBlock.traverse(visitor, this.scope);
}
visitor.endVisit(this, blockScope);
}
}
