/**
* 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 ((bits & IsReachableMASK) == 0) {
return;
}
// in case the labels needs to be reinitialized
// when the code generation is restarted in wide mode
if (this.anyExceptionLabelsCount > 0) {
this.anyExceptionLabels = NO_EXCEPTION_HANDLER;
this.anyExceptionLabelsCount = 0;
}
int pc = codeStream.position;
final int NO_FINALLY = 0; // no finally block
final int FINALLY_SUBROUTINE =
1; // finally is generated as a subroutine (using jsr/ret bytecodes)
final int FINALLY_DOES_NOT_COMPLETE =
2; // non returning finally is optimized with only one instance of finally block
final int FINALLY_MUST_BE_INLINED =
3; // finally block must be inlined since cannot use jsr/ret bytecodes >1.5
int finallyMode;
if (subRoutineStartLabel == null) {
finallyMode = NO_FINALLY;
} else {
if (this.isSubRoutineEscaping) {
finallyMode = FINALLY_DOES_NOT_COMPLETE;
} else if (scope.compilerOptions().inlineJsrBytecode) {
finallyMode = FINALLY_MUST_BE_INLINED;
} else {
finallyMode = FINALLY_SUBROUTINE;
}
}
boolean requiresNaturalExit = false;
// preparing exception labels
int maxCatches;
ExceptionLabel[] exceptionLabels =
new ExceptionLabel[maxCatches = catchArguments == null ? 0 : catchArguments.length];
for (int i = 0; i < maxCatches; i++) {
exceptionLabels[i] = new ExceptionLabel(codeStream, catchArguments[i].binding.type);
}
if (subRoutineStartLabel != null) {
subRoutineStartLabel.initialize(codeStream);
this.enterAnyExceptionHandler(codeStream);
}
// generate the try block
tryBlock.generateCode(scope, codeStream);
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)
Label naturalExitLabel = new Label(codeStream);
if (!tryBlockExit) {
int position = codeStream.position;
switch (finallyMode) {
case FINALLY_SUBROUTINE:
case FINALLY_MUST_BE_INLINED:
requiresNaturalExit = true;
// fall through
case NO_FINALLY:
codeStream.goto_(naturalExitLabel);
break;
case FINALLY_DOES_NOT_COMPLETE:
codeStream.goto_(subRoutineStartLabel);
break;
}
codeStream.updateLastRecordedEndPC(tryBlock.scope, position);
// goto is tagged as part of the try block
}
for (int i = 0; i < maxCatches; i++) {
exceptionLabels[i].placeEnd();
}
/* 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.
*/
if (catchArguments != null) {
for (int i = 0; i < maxCatches; i++) {
// May loose some local variable initializations : affecting the local variable attributes
if (preTryInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
}
exceptionLabels[i].place();
codeStream.incrStackSize(1);
// optimizing the case where the exception variable is not actually used
LocalVariableBinding catchVar;
int varPC = codeStream.position;
if ((catchVar = catchArguments[i].binding).resolvedPosition != -1) {
codeStream.store(catchVar, false);
catchVar.recordInitializationStartPC(codeStream.position);
codeStream.addVisibleLocalVariable(catchVar);
} else {
codeStream.pop();
}
codeStream.recordPositionsFrom(varPC, 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)
catchBlocks[i].generateCode(scope, codeStream);
if (!catchExits[i]) {
switch (finallyMode) {
case FINALLY_SUBROUTINE:
case FINALLY_MUST_BE_INLINED:
requiresNaturalExit = true;
// fall through
case NO_FINALLY:
codeStream.goto_(naturalExitLabel);
break;
case FINALLY_DOES_NOT_COMPLETE:
codeStream.goto_(subRoutineStartLabel);
break;
}
}
}
}
this.exitAnyExceptionHandler();
// extra handler for trailing natural exit (will be fixed up later on when natural exit is
// generated below)
ExceptionLabel naturalExitExceptionHandler =
finallyMode == FINALLY_SUBROUTINE && requiresNaturalExit
? 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 (subRoutineStartLabel != null) {
this.placeAllAnyExceptionHandlers();
if (naturalExitExceptionHandler != null) naturalExitExceptionHandler.place();
if (preTryInitStateIndex != -1) {
// reset initialization state, as for a normal catch block
codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
}
codeStream.incrStackSize(1);
switch (finallyMode) {
case FINALLY_SUBROUTINE:
codeStream.store(anyExceptionVariable, false);
codeStream.jsr(subRoutineStartLabel);
codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
int position = codeStream.position;
codeStream.load(anyExceptionVariable);
codeStream.athrow();
codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
subRoutineStartLabel.place();
codeStream.incrStackSize(1);
position = codeStream.position;
codeStream.store(returnAddressVariable, false);
codeStream.recordPositionsFrom(position, finallyBlock.sourceStart);
finallyBlock.generateCode(scope, codeStream);
position = codeStream.position;
codeStream.ret(returnAddressVariable.resolvedPosition);
// codeStream.updateLastRecordedEndPC(position);
codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
// the ret bytecode is part of the subroutine
break;
case FINALLY_MUST_BE_INLINED:
codeStream.store(anyExceptionVariable, false);
codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
this.finallyBlock.generateCode(currentScope, codeStream);
position = codeStream.position;
codeStream.load(anyExceptionVariable);
codeStream.athrow();
subRoutineStartLabel.place();
codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
break;
case FINALLY_DOES_NOT_COMPLETE:
codeStream.pop();
subRoutineStartLabel.place();
codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
finallyBlock.generateCode(scope, codeStream);
break;
}
// will naturally fall into subsequent code after subroutine invocation
naturalExitLabel.place();
if (requiresNaturalExit) {
switch (finallyMode) {
case FINALLY_SUBROUTINE:
int position = codeStream.position;
// fix up natural exit handler
naturalExitExceptionHandler.placeStart();
codeStream.jsr(subRoutineStartLabel);
naturalExitExceptionHandler.placeEnd();
codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
break;
case FINALLY_MUST_BE_INLINED:
// May loose some local variable initializations : affecting the local variable
// attributes
// needed since any exception handler got inlined subroutine
if (preTryInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
}
// entire sequence for finally is associated to finally block
finallyBlock.generateCode(scope, codeStream);
break;
case FINALLY_DOES_NOT_COMPLETE:
break;
}
}
} 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 (subRoutineStartLabel != null) {
finallyBlock.generateCode(scope, codeStream);
}
}
// May loose some local variable initializations : affecting the local variable attributes
if (mergedInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
/**
* 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);
}