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;
}
}
