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
preTryInitStateIndex = currentScope.methodScope().recordInitializationStates(flowInfo);
if (anyExceptionVariable != null) {
anyExceptionVariable.useFlag = LocalVariableBinding.USED;
}
if (returnAddressVariable != null) { // TODO (philippe) if subroutine is escaping, unused
returnAddressVariable.useFlag = LocalVariableBinding.USED;
}
InsideSubRoutineFlowContext insideSubContext;
FinallyFlowContext finallyContext;
UnconditionalFlowInfo subInfo;
if (subRoutineStartLabel == null) {
// no finally block
insideSubContext = null;
finallyContext = null;
subInfo = null;
} else {
// analyse finally block first
insideSubContext = new InsideSubRoutineFlowContext(flowContext, this);
subInfo =
finallyBlock
.analyseCode(
currentScope,
finallyContext = new FinallyFlowContext(flowContext, finallyBlock),
flowInfo.copy().unconditionalInits().discardNullRelatedInitializations())
.unconditionalInits();
if (subInfo == FlowInfo.DEAD_END) {
isSubRoutineEscaping = true;
scope.problemReporter().finallyMustCompleteNormally(finallyBlock);
}
this.subRoutineInits = subInfo;
}
// process the try block in a context handling the local exceptions.
ExceptionHandlingFlowContext handlingContext =
new ExceptionHandlingFlowContext(
insideSubContext == null ? flowContext : insideSubContext,
tryBlock,
caughtExceptionTypes,
scope,
flowInfo.unconditionalInits());
FlowInfo tryInfo;
if (tryBlock.isEmptyBlock()) {
tryInfo = flowInfo;
tryBlockExit = false;
} else {
tryInfo = tryBlock.analyseCode(currentScope, handlingContext, flowInfo.copy());
tryBlockExit = !tryInfo.isReachable();
}
// check unreachable catch blocks
handlingContext.complainIfUnusedExceptionHandlers(scope, this);
// process the catch blocks - computing the minimal exit depth amongst try/catch
if (catchArguments != null) {
int catchCount;
catchExits = new boolean[catchCount = catchBlocks.length];
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 =
flowInfo
.copy()
.unconditionalInits()
.addPotentialInitializationsFrom(
handlingContext.initsOnException(caughtExceptionTypes[i]).unconditionalInits())
.addPotentialInitializationsFrom(tryInfo.unconditionalInits())
.addPotentialInitializationsFrom(handlingContext.initsOnReturn);
// catch var is always set
LocalVariableBinding catchArg = catchArguments[i].binding;
FlowContext catchContext = insideSubContext == null ? flowContext : insideSubContext;
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 (tryBlock.statements == null) {
catchInfo.setReachMode(FlowInfo.UNREACHABLE);
}
catchInfo = catchBlocks[i].analyseCode(currentScope, catchContext, catchInfo);
catchExits[i] = !catchInfo.isReachable();
tryInfo = tryInfo.mergedWith(catchInfo.unconditionalInits());
}
}
if (subRoutineStartLabel == null) {
mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(tryInfo);
return tryInfo;
}
// 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(
tryInfo.isReachable()
? (tryInfo.addPotentialInitializationsFrom(insideSubContext.initsOnReturn))
: insideSubContext.initsOnReturn,
currentScope);
if (subInfo == FlowInfo.DEAD_END) {
mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(subInfo);
return subInfo;
} else {
FlowInfo mergedInfo = tryInfo.addInitializationsFrom(subInfo);
mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(mergedInfo);
return mergedInfo;
}
}
public void resolve(BlockScope upperScope) {
// special scope for secret locals optimization.
this.scope = new BlockScope(upperScope);
BlockScope tryScope = new BlockScope(scope);
BlockScope finallyScope = null;
if (finallyBlock != null) {
if (finallyBlock.isEmptyBlock()) {
if ((finallyBlock.bits & UndocumentedEmptyBlockMASK) != 0) {
scope
.problemReporter()
.undocumentedEmptyBlock(finallyBlock.sourceStart, finallyBlock.sourceEnd);
}
} else {
finallyScope = new BlockScope(scope, false); // don't add it yet to parent scope
// provision for returning and forcing the finally block to run
MethodScope methodScope = scope.methodScope();
// the type does not matter as long as it is not a base type
if (!upperScope.compilerOptions().inlineJsrBytecode) {
this.returnAddressVariable =
new LocalVariableBinding(
SecretReturnName, upperScope.getJavaLangObject(), AccDefault, false);
finallyScope.addLocalVariable(returnAddressVariable);
this.returnAddressVariable.setConstant(NotAConstant); // not inlinable
}
this.subRoutineStartLabel = new Label();
this.anyExceptionVariable =
new LocalVariableBinding(
SecretAnyHandlerName, scope.getJavaLangThrowable(), AccDefault, false);
finallyScope.addLocalVariable(this.anyExceptionVariable);
this.anyExceptionVariable.setConstant(NotAConstant); // not inlinable
if (!methodScope.isInsideInitializer()) {
MethodBinding methodBinding =
((AbstractMethodDeclaration) methodScope.referenceContext).binding;
if (methodBinding != null) {
TypeBinding methodReturnType = methodBinding.returnType;
if (methodReturnType.id != T_void) {
this.secretReturnValue =
new LocalVariableBinding(
SecretLocalDeclarationName, methodReturnType, AccDefault, false);
finallyScope.addLocalVariable(this.secretReturnValue);
this.secretReturnValue.setConstant(NotAConstant); // not inlinable
}
}
}
finallyBlock.resolveUsing(finallyScope);
// force the finally scope to have variable positions shifted after its try scope and catch
// ones
finallyScope.shiftScopes =
new BlockScope[catchArguments == null ? 1 : 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(scope);
if (finallyScope != null) {
finallyScope.shiftScopes[i + 1] = catchScope;
}
// side effect on catchScope in resolveForCatch(..)
if ((argumentTypes[i] = catchArguments[i].resolveForCatch(catchScope)) == null) {
catchHasError = true;
}
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++) {
caughtExceptionTypes[i] = (ReferenceBinding) argumentTypes[i];
for (int j = 0; j < i; j++) {
if (caughtExceptionTypes[i].isCompatibleWith(argumentTypes[j])) {
scope
.problemReporter()
.wrongSequenceOfExceptionTypesError(
this, caughtExceptionTypes[i], i, argumentTypes[j]);
}
}
}
} else {
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);
}
}