UsedVarsFixpointIterator::UsedVarsFixpointIterator(
const local_pointers::FixpointIterator& pointers_fp_iter,
const EffectSummaryMap& effect_summaries,
const std::unordered_set<const DexMethod*>& non_overridden_virtuals,
const cfg::ControlFlowGraph& cfg)
: MonotonicFixpointIterator(cfg, cfg.blocks().size()),
m_insn_env_map(gen_instruction_environment_map(cfg, pointers_fp_iter)),
m_effect_summaries(effect_summaries),
m_non_overridden_virtuals(non_overridden_virtuals) {}
/*
* Record the environment before the execution of every instruction. We need
* this data during the backwards used vars analysis.
*/
static std::unordered_map<const IRInstruction*, ptrs::Environment>
gen_instruction_environment_map(const cfg::ControlFlowGraph& cfg,
const ptrs::FixpointIterator& fp_iter) {
std::unordered_map<const IRInstruction*, ptrs::Environment> result;
for (auto* block : cfg.blocks()) {
auto env = fp_iter.get_entry_state_at(block);
for (auto& mie : InstructionIterable(block)) {
auto* insn = mie.insn;
result.emplace(insn, env);
fp_iter.analyze_instruction(insn, &env);
}
}
return result;
}
std::string show(const cfg::ControlFlowGraph& cfg) {
const auto& blocks = cfg.blocks();
std::ostringstream ss;
ss << "CFG:\n";
for (const auto& b : blocks) {
ss << " Block B" << b->id() << ":\n";
ss << " preds:";
for (const auto& p : b->preds()) {
ss << " (" << *p << " B" << p->src()->id() << ")";
}
ss << "\n";
ss << show(b);
ss << " succs:";
for (auto& s : b->succs()) {
ss << " (" << *s << " B" << s->target()->id() << ")";
}
ss << "\n";
}
return ss.str();
}