void c_typecheck_baset::typecheck_array_type(array_typet &type) { exprt &size=type.size(); locationt location=size.find_location(); // check subtype typecheck_type(type.subtype()); // we don't allow void as subtype if(follow(type.subtype()).id()==ID_empty) { err_location(type); str << "array of voids"; throw 0; } // check size, if any if(size.is_not_nil()) { typecheck_expr(size); make_index_type(size); // The size need not be a constant! // We simplify it, for the benefit of array initialisation. exprt tmp_size=size; simplify(tmp_size, *this); if(tmp_size.is_constant()) { mp_integer s; if(to_integer(tmp_size, s)) { err_location(location); str << "failed to convert constant: " << tmp_size.pretty(); throw 0; } if(s<0) { err_location(location); str << "array size must not be negative, " "but got " << s; throw 0; } size=tmp_size; } else if(tmp_size.id()==ID_infinity) size=tmp_size; } }
exprt boolbvt::bv_get_unbounded_array( const irep_idt &identifier, const array_typet &type) const { // first, try to get size const exprt &size_expr=type.size(); exprt size=get(size_expr); // no size, give up if(size.is_nil()) return nil_exprt(); // get the numeric value, unless it's infinity mp_integer size_mpint; if(size.id()!=ID_infinity) { if(to_integer(size, size_mpint)) return nil_exprt(); // simple sanity check if(size_mpint<0) return nil_exprt(); } else size_mpint=0; // search array indices typedef std::map<mp_integer, exprt> valuest; valuest values; { unsigned number; symbol_exprt array_expr; array_expr.type()=type; array_expr.set_identifier(identifier); if(arrays.get_number(array_expr, number)) return nil_exprt(); // get root number=arrays.find_number(number); assert(number<index_map.size()); const index_sett &index_set=index_map[number]; for(index_sett::const_iterator it1= index_set.begin(); it1!=index_set.end(); it1++) { index_exprt index; index.type()=type.subtype(); index.array()=array_expr; index.index()=*it1; exprt value=bv_get_cache(index); exprt index_value=bv_get_cache(*it1); if(!index_value.is_nil()) { mp_integer index_mpint; if(!to_integer(index_value, index_mpint)) { if(value.is_nil()) values[index_mpint]=exprt(ID_unknown, type.subtype()); else values[index_mpint]=value; } } } } exprt result; if(size_mpint>100 || size.id()==ID_infinity) { result=exprt("array-list", type); result.type().set(ID_size, integer2string(size_mpint)); result.operands().reserve(values.size()*2); for(valuest::const_iterator it=values.begin(); it!=values.end(); it++) { exprt index=from_integer(it->first, size.type()); result.copy_to_operands(index, it->second); } } else { // set the size result=exprt(ID_array, type); result.type().set(ID_size, size); unsigned long size_int=integer2long(size_mpint); // allocate operands result.operands().resize(size_int); for(unsigned i=0; i<size_int; i++) result.operands()[i]=exprt(ID_unknown); // search uninterpreted functions for(valuest::iterator it=values.begin(); it!=values.end(); it++) if(it->first>=0 && it->first<size_mpint) result.operands()[integer2long(it->first)].swap(it->second); } return result; }
void c_typecheck_baset::typecheck_array_type(array_typet &type) { exprt &size=type.size(); source_locationt source_location=size.find_source_location(); // check subtype typecheck_type(type.subtype()); // we don't allow void as subtype if(follow(type.subtype()).id()==ID_empty) { error().source_location=type.source_location(); error() << "array of voids" << eom; throw 0; } // check size, if any if(size.is_not_nil()) { typecheck_expr(size); make_index_type(size); // The size need not be a constant! // We simplify it, for the benefit of array initialisation. exprt tmp_size=size; add_rounding_mode(tmp_size); simplify(tmp_size, *this); if(tmp_size.is_constant()) { mp_integer s; if(to_integer(tmp_size, s)) { error().source_location=source_location; error() << "failed to convert constant: " << tmp_size.pretty() << eom; throw 0; } if(s<0) { error().source_location=source_location; error() << "array size must not be negative, " "but got " << s << eom; throw 0; } size=tmp_size; } else if(tmp_size.id()==ID_infinity) { size=tmp_size; } else if(tmp_size.id()==ID_symbol && tmp_size.type().get_bool(ID_C_constant)) { // We allow a constant variable as array size, assuming // it won't change. // This criterion can be tricked: // Of course we can modify a 'const' symbol, e.g., // using a pointer type cast. Interestingly, // at least gcc 4.2.1 makes the very same mistake! size=tmp_size; } else { // not a constant and not infinity assert(current_symbol_id!=irep_idt()); const symbolt &base_symbol=lookup(current_symbol_id); // Need to pull out! We insert new symbol. source_locationt source_location=size.find_source_location(); unsigned count=0; irep_idt temp_identifier; std::string suffix; do { suffix="$array_size"+std::to_string(count); temp_identifier=id2string(base_symbol.name)+suffix; count++; } while(symbol_table.symbols.find(temp_identifier)!= symbol_table.symbols.end()); // add the symbol to symbol table auxiliary_symbolt new_symbol; new_symbol.name=temp_identifier; new_symbol.pretty_name=id2string(base_symbol.pretty_name)+suffix; new_symbol.base_name=id2string(base_symbol.base_name)+suffix; new_symbol.type=size.type(); new_symbol.type.set(ID_C_constant, true); new_symbol.is_type=false; new_symbol.is_static_lifetime=false; new_symbol.value.make_nil(); new_symbol.location=source_location; symbol_table.add(new_symbol); // produce the code that declares and initializes the symbol symbol_exprt symbol_expr; symbol_expr.set_identifier(temp_identifier); symbol_expr.type()=new_symbol.type; code_declt declaration(symbol_expr); declaration.add_source_location()=source_location; code_assignt assignment; assignment.lhs()=symbol_expr; assignment.rhs()=size; assignment.add_source_location()=source_location; // store the code clean_code.push_back(declaration); clean_code.push_back(assignment); // fix type size=symbol_expr; } } }
void boolbvt::convert_with_array( const array_typet &type, const exprt &op1, const exprt &op2, const bvt &prev_bv, bvt &next_bv) { if(is_unbounded_array(type)) { // can't do this error().source_location=type.source_location(); error() << "convert_with_array called for unbounded array" << eom; throw 0; } const exprt &array_size=type.size(); mp_integer size; if(to_integer(array_size, size)) { error().source_location=type.source_location(); error() << "convert_with_array expects constant array size" << eom; throw 0; } const bvt &op2_bv=convert_bv(op2); if(size*op2_bv.size()!=prev_bv.size()) { error().source_location=type.source_location(); error() << "convert_with_array: unexpected operand 2 width" << eom; throw 0; } // Is the index a constant? mp_integer op1_value; if(!to_integer(op1, op1_value)) { // Yes, it is! next_bv=prev_bv; if(op1_value>=0 && op1_value<size) // bounds check { std::size_t offset=integer2unsigned(op1_value*op2_bv.size()); for(std::size_t j=0; j<op2_bv.size(); j++) next_bv[offset+j]=op2_bv[j]; } return; } typet counter_type=op1.type(); for(mp_integer i=0; i<size; i=i+1) { exprt counter=from_integer(i, counter_type); literalt eq_lit=convert(equal_exprt(op1, counter)); std::size_t offset=integer2unsigned(i*op2_bv.size()); for(std::size_t j=0; j<op2_bv.size(); j++) next_bv[offset+j]= prop.lselect(eq_lit, op2_bv[j], prev_bv[offset+j]); } }