void goto_convertt::do_cpp_new(
const exprt &lhs,
const side_effect_exprt &rhs,
goto_programt &dest)
{
if(lhs.is_nil())
throw "do_cpp_new without lhs is yet to be implemented";
// build size expression
exprt object_size=
static_cast<const exprt &>(rhs.find(ID_sizeof));
bool new_array=rhs.get(ID_statement)==ID_cpp_new_array;
exprt count;
if(new_array)
{
count=static_cast<const exprt &>(rhs.find(ID_size));
if(count.type()!=object_size.type())
count.make_typecast(object_size.type());
// might have side-effect
clean_expr(count, dest);
}
exprt tmp_symbol_expr;
// is this a placement new?
if(rhs.operands().empty()) // no, "regular" one
{
// call __new or __new_array
exprt new_symbol=
ns.lookup(new_array?"__new_array":"__new").symbol_expr();
const code_typet &code_type=
to_code_type(new_symbol.type());
const typet &return_type=
code_type.return_type();
assert(code_type.parameters().size()==1 ||
code_type.parameters().size()==2);
const symbolt &tmp_symbol=
new_tmp_symbol(return_type, "new", dest, rhs.source_location());
tmp_symbol_expr=tmp_symbol.symbol_expr();
code_function_callt new_call;
new_call.function()=new_symbol;
if(new_array) new_call.arguments().push_back(count);
new_call.arguments().push_back(object_size);
new_call.set("#type", lhs.type().subtype());
new_call.lhs()=tmp_symbol_expr;
new_call.add_source_location()=rhs.source_location();
convert(new_call, dest);
}
else if(rhs.operands().size()==1)
{
// call __placement_new
exprt new_symbol=
ns.lookup(new_array?"__placement_new_array":"__placement_new").symbol_expr();
const code_typet &code_type=
to_code_type(new_symbol.type());
const typet &return_type=code_type.return_type();
assert(code_type.parameters().size()==2 ||
code_type.parameters().size()==3);
const symbolt &tmp_symbol=
new_tmp_symbol(return_type, "new", dest, rhs.source_location());
tmp_symbol_expr=tmp_symbol.symbol_expr();
code_function_callt new_call;
new_call.function()=new_symbol;
if(new_array) new_call.arguments().push_back(count);
new_call.arguments().push_back(object_size);
new_call.arguments().push_back(rhs.op0()); // memory location
new_call.set("#type", lhs.type().subtype());
new_call.lhs()=tmp_symbol_expr;
new_call.add_source_location()=rhs.source_location();
for(unsigned i=0; i<code_type.parameters().size(); i++)
if(new_call.arguments()[i].type()!=code_type.parameters()[i].type())
new_call.arguments()[i].make_typecast(code_type.parameters()[i].type());
convert(new_call, dest);
}
else
throw "cpp_new expected to have 0 or 1 operands";
goto_programt::targett t_n=dest.add_instruction(ASSIGN);
t_n->code=code_assignt(
lhs, typecast_exprt(tmp_symbol_expr, lhs.type()));
t_n->source_location=rhs.find_source_location();
// grab initializer
goto_programt tmp_initializer;
cpp_new_initializer(lhs, rhs, tmp_initializer);
dest.destructive_append(tmp_initializer);
}
void goto_convertt::clean_expr(
exprt &expr,
goto_programt &dest,
bool result_is_used)
{
// this cleans:
// && || ?: comma (control-dependency)
// function calls
// object constructors like arrays, string constants, structs
// ++ --
// compound assignments
// compound literals
if(!needs_cleaning(expr)) return;
if(expr.id()==ID_and || expr.id()==ID_or)
{
// rewrite into ?:
rewrite_boolean(expr);
// recursive call
clean_expr(expr, dest, result_is_used);
return;
}
else if(expr.id()==ID_if)
{
// first clean condition
clean_expr(to_if_expr(expr).cond(), dest, true);
// possibly done now
if(!needs_cleaning(to_if_expr(expr).true_case()) &&
!needs_cleaning(to_if_expr(expr).false_case()))
return;
// copy expression
if_exprt if_expr=to_if_expr(expr);
if(!if_expr.cond().is_boolean())
throw "first argument of `if' must be boolean, but got "
+if_expr.cond().to_string();
const locationt location=expr.find_location();
// We do some constant-folding here, to mimic
// what typical compilers do.
{
exprt tmp_cond=if_expr.cond();
simplify(tmp_cond, ns);
if(tmp_cond.is_true())
{
clean_expr(if_expr.true_case(), dest, result_is_used);
expr=if_expr.true_case();
return;
}
else if(tmp_cond.is_false())
{
clean_expr(if_expr.false_case(), dest, result_is_used);
expr=if_expr.false_case();
return;
}
}
goto_programt tmp_true;
clean_expr(if_expr.true_case(), tmp_true, result_is_used);
goto_programt tmp_false;
clean_expr(if_expr.false_case(), tmp_false, result_is_used);
if(result_is_used)
{
symbolt &new_symbol=
new_tmp_symbol(expr.type(), "if_expr", dest, location);
code_assignt assignment_true;
assignment_true.lhs()=new_symbol.symbol_expr();
assignment_true.rhs()=if_expr.true_case();
assignment_true.location()=location;
convert(assignment_true, tmp_true);
code_assignt assignment_false;
assignment_false.lhs()=new_symbol.symbol_expr();
assignment_false.rhs()=if_expr.false_case();
assignment_false.location()=location;
convert(assignment_false, tmp_false);
// overwrites expr
expr=new_symbol.symbol_expr();
}
else
{
// preserve the expressions for possible later checks
if(if_expr.true_case().is_not_nil())
{
code_expressiont code_expression(if_expr.true_case());
convert(code_expression, tmp_true);
}
if(if_expr.false_case().is_not_nil())
{
code_expressiont code_expression(if_expr.false_case());
convert(code_expression, tmp_false);
}
expr=nil_exprt();
}
// generate guard for argument side-effects
generate_ifthenelse(
if_expr.cond(), tmp_true, tmp_false,
location, dest);
return;
}
else if(expr.id()==ID_comma)
{
if(result_is_used)
{
exprt result;
Forall_operands(it, expr)
{
bool last=(it==--expr.operands().end());
// special treatment for last one
if(last)
{
result.swap(*it);
clean_expr(result, dest, true);
}
else
{
clean_expr(*it, dest, false);
// remember these for later checks
if(it->is_not_nil())
convert(code_expressiont(*it), dest);
}
}
expr.swap(result);
}
else // result not used
{
