static bool runOnBlock(const CFGBlock *block, const CFG &cfg,
AnalysisDeclContext &ac, CFGBlockValues &vals,
llvm::BitVector &wasAnalyzed,
UninitVariablesHandler *handler = 0) {
wasAnalyzed[block->getBlockID()] = true;
if (const BinaryOperator *b = getLogicalOperatorInChain(block)) {
CFGBlock::const_pred_iterator itr = block->pred_begin();
BVPair vA = vals.getValueVectors(*itr, false);
++itr;
BVPair vB = vals.getValueVectors(*itr, false);
BVPair valsAB;
if (b->getOpcode() == BO_LAnd) {
// Merge the 'F' bits from the first and second.
vals.mergeIntoScratch(*(vA.second ? vA.second : vA.first), true);
vals.mergeIntoScratch(*(vB.second ? vB.second : vB.first), false);
valsAB.first = vA.first;
valsAB.second = &vals.getScratch();
} else {
// Merge the 'T' bits from the first and second.
assert(b->getOpcode() == BO_LOr);
vals.mergeIntoScratch(*vA.first, true);
vals.mergeIntoScratch(*vB.first, false);
valsAB.first = &vals.getScratch();
valsAB.second = vA.second ? vA.second : vA.first;
}
return vals.updateValueVectors(block, valsAB);
}
// Default behavior: merge in values of predecessor blocks.
vals.resetScratch();
bool isFirst = true;
for (CFGBlock::const_pred_iterator I = block->pred_begin(),
E = block->pred_end(); I != E; ++I) {
const CFGBlock *pred = *I;
if (wasAnalyzed[pred->getBlockID()]) {
vals.mergeIntoScratch(vals.getValueVector(pred, block), isFirst);
isFirst = false;
}
}
// Apply the transfer function.
TransferFunctions tf(vals, cfg, ac, handler);
for (CFGBlock::const_iterator I = block->begin(), E = block->end();
I != E; ++I) {
if (const CFGStmt *cs = dyn_cast<CFGStmt>(&*I)) {
tf.Visit(const_cast<Stmt*>(cs->getStmt()));
}
}
tf.ProcessUses();
return vals.updateValueVectorWithScratch(block);
}
