goto_functionst &functions,

message_handlert &message_handler)

{

std::set<irep_idt> used_functions;

std::list<goto_functionst::function_mapt::iterator> unused_functions;

find_used_functions(

goto_functionst::entry_point(), functions, used_functions);

for(goto_functionst::function_mapt::iterator it=

functions.function_map.begin();

it!=functions.function_map.end();

it++)

{

if(used_functions.find(it->first)==used_functions.end())

unused_functions.push_back(it);

}

messaget message(message_handler);

if(!unused_functions.empty())

{

message.statistics()

<< "Dropping " << unused_functions.size() << " of " <<

functions.function_map.size() << " functions (" <<

used_functions.size() << " used)" << messaget::eom;

}

for(const auto &f : unused_functions)

functions.function_map.erase(f);

const irep_idt &start,

goto_functionst &functions,

std::set<irep_idt> &seen)

{

std::pair<std::set<irep_idt>::const_iterator, bool> res =

seen.insert(start);

if(!res.second)

return;

else

{

goto_functionst::function_mapt::const_iterator f_it =

functions.function_map.find(start);

if(f_it!=functions.function_map.end())

{

forall_goto_program_instructions(it, f_it->second.body)

{

if(it->type==FUNCTION_CALL)

{

const code_function_callt &call =

to_code_function_call(to_code(it->code));

// check that this is actually a simple call

assert(call.function().id()==ID_symbol);

find_used_functions(call.function().get(ID_identifier),

functions,

seen);

}

}

}

}