void goto_symext::symex_other(
const goto_functionst &goto_functions,
statet &state)
{
const goto_programt::instructiont &instruction=*state.source.pc;
const codet &code=to_code(instruction.code);
const irep_idt &statement=code.get_statement();
if(statement==ID_expression)
{
// ignore
}
else if(statement==ID_cpp_delete ||
statement=="cpp_delete[]")
{
codet clean_code=code;
clean_expr(clean_code, state, false);
symex_cpp_delete(state, clean_code);
}
else if(statement==ID_free)
{
// ignore
}
else if(statement==ID_printf)
{
codet clean_code=code;
clean_expr(clean_code, state, false);
symex_printf(state, nil_exprt(), clean_code);
}
else if(statement==ID_input)
{
codet clean_code(code);
clean_expr(clean_code, state, false);
symex_input(state, clean_code);
}
else if(statement==ID_output)
{
codet clean_code(code);
clean_expr(clean_code, state, false);
symex_output(state, clean_code);
}
else if(statement==ID_decl)
{
assert(false); // see symex_decl.cpp
}
else if(statement==ID_nondet)
{
// like skip
}
else if(statement==ID_asm)
{
// we ignore this for now
}
else if(statement==ID_array_copy)
{
assert(code.operands().size()==2);
codet clean_code(code);
// we need to add dereferencing for both operands
dereference_exprt d0, d1;
d0.op0()=code.op0();
d0.type()=code.op0().type().subtype();
d1.op0()=code.op1();
d1.type()=code.op1().type().subtype();
clean_code.op0()=d0;
clean_code.op1()=d1;
clean_expr(clean_code, state, false);
process_array_expr(clean_code.op0());
process_array_expr(clean_code.op1());
if(ns.follow(clean_code.op0().type()).id()!=ID_array)
throw "array_copy expects array operand";
if(!base_type_eq(clean_code.op0().type(),
clean_code.op1().type(), ns))
throw "array_copy expects matching array types";
code_assignt assignment;
assignment.lhs()=clean_code.op0();
assignment.rhs()=clean_code.op1();
basic_symext::symex_assign(state, assignment);
}
else if(statement==ID_array_set)
{
assert(code.operands().size()==2);
codet clean_code(code);
// we need to add dereferencing for the first operand
dereference_exprt d0;
d0.op0()=code.op0();
d0.type()=code.op0().type().subtype();
clean_code.op0()=d0;
clean_expr(clean_code, state, false);
process_array_expr(clean_code.op0());
const typet &array_type=ns.follow(clean_code.op0().type());
if(array_type.id()!=ID_array)
throw "array_set expects array operand";
if(!base_type_eq(array_type.subtype(),
clean_code.op1().type(), ns))
clean_code.op1().make_typecast(array_type.subtype());
code_assignt assignment;
assignment.lhs()=clean_code.op0();
assignment.rhs()=array_of_exprt(clean_code.op1(), clean_code.op0().type());
basic_symext::symex_assign(state, assignment);
}
else if(statement==ID_user_specified_predicate || statement==ID_user_specified_parameter_predicates || statement == ID_user_specified_return_predicates)
{
// like skip
}
else
throw "unexpected statement: "+id2string(statement);
}
void goto_symext::symex_other()
{
const goto_programt::instructiont &instruction = *cur_state->source.pc;
expr2tc code2 = instruction.code;
if(is_code_expression2t(code2))
{
// Represents an expression that gets evaluated, but does not have any
// other effect on execution, i.e. doesn't contain a call or assignment.
// This can, however, cause the program to fail if it dereferences an
// invalid pointer. Therefore, dereference it.
const code_expression2t &expr = to_code_expression2t(code2);
expr2tc operand = expr.operand;
dereference(operand, dereferencet::READ);
}
else if(is_code_cpp_del_array2t(code2) || is_code_cpp_delete2t(code2))
{
expr2tc deref_code(code2);
replace_dynamic_allocation(deref_code);
replace_nondet(deref_code);
dereference(deref_code, dereferencet::READ);
symex_cpp_delete(deref_code);
}
else if(is_code_free2t(code2))
{
symex_free(code2);
}
else if(is_code_printf2t(code2))
{
replace_dynamic_allocation(code2);
replace_nondet(code2);
dereference(code2, dereferencet::READ);
symex_printf(expr2tc(), code2);
}
else if(is_code_decl2t(code2))
{
replace_dynamic_allocation(code2);
replace_nondet(code2);
dereference(code2, dereferencet::READ);
const code_decl2t &decl_code = to_code_decl2t(code2);
// just do the L2 renaming to preseve locality
const irep_idt &identifier = decl_code.value;
// Generate dummy symbol as a vehicle for renaming.
symbol2tc l1_sym(get_empty_type(), identifier);
cur_state->top().level1.get_ident_name(l1_sym);
symbol2t &l1_symbol = to_symbol2t(l1_sym);
// increase the frame if we have seen this declaration before
while(cur_state->top().declaration_history.find(
renaming::level2t::name_record(l1_symbol)) !=
cur_state->top().declaration_history.end())
{
unsigned &index = cur_state->variable_instance_nums[identifier];
cur_state->top().level1.rename(l1_sym, ++index);
l1_symbol.level1_num = index;
}
renaming::level2t::name_record tmp_name(l1_symbol);
cur_state->top().declaration_history.insert(tmp_name);
cur_state->top().local_variables.insert(tmp_name);
// seen it before?
// it should get a fresh value
if(cur_state->level2.current_number(l1_sym) != 0)
{
// Dummy assignment - blank constant value isn't considered for const
// propagation, variable number will be bumped to result in a new free
// variable. Invalidates l1_symbol reference?
cur_state->level2.make_assignment(l1_sym, expr2tc(), expr2tc());
}
}
else if(is_code_asm2t(code2))
{
// Assembly statement -> do nothing.
return;
}
else
throw "goto_symext: unexpected statement: " + get_expr_id(code2);
}