void c_typecheck_baset::typecheck_assign(codet &code)
{
if(code.operands().size()!=2)
{
err_location(code);
error() << "assignment statement expected to have two operands"
<< eom;
throw 0;
}
typecheck_expr(code.op0());
typecheck_expr(code.op1());
implicit_typecast(code.op1(), code.op0().type());
}
void goto_convertt::convert_CPROVER_try_catch(
const codet &code,
goto_programt &dest)
{
if(code.operands().size()!=2)
{
err_location(code);
throw "CPROVER_try_catch expects two arguments";
}
// this is where we go after 'throw'
goto_programt tmp;
tmp.add_instruction(SKIP)->source_location=code.source_location();
// set 'throw' target
throw_targett throw_target(targets);
targets.set_throw(tmp.instructions.begin());
// now put 'catch' code onto destructor stack
code_ifthenelset catch_code;
catch_code.cond()=exception_flag();
catch_code.add_source_location()=code.source_location();
catch_code.then_case()=to_code(code.op1());
targets.destructor_stack.push_back(catch_code);
// now convert 'try' code
convert(to_code(code.op0()), dest);
// pop 'catch' code off stack
targets.destructor_stack.pop_back();
// add 'throw' target
dest.destructive_append(tmp);
}
void rw_sett::compute(const codet &code)
{
const irep_idt &statement=code.get_statement();
if(statement==ID_assign)
{
assert(code.operands().size()==2);
assign(code.op0(), code.op1());
}
}
void goto_convertt::convert_CPROVER_try_finally(
const codet &code,
goto_programt &dest)
{
if(code.operands().size()!=2)
{
err_location(code);
throw "CPROVER_try_finally expects two arguments";
}
// first put 'finally' code onto destructor stack
targets.destructor_stack.push_back(to_code(code.op1()));
// do 'try' code
convert(to_code(code.op0()), dest);
// pop 'finally' from destructor stack
targets.destructor_stack.pop_back();
// now add 'finally' code
convert(to_code(code.op1()), dest);
}
void goto_convertt::convert_msc_try_finally(
const codet &code,
goto_programt &dest)
{
if(code.operands().size()!=2)
{
error().source_location=code.find_source_location();
error() << "msc_try_finally expects two arguments" << eom;
throw 0;
}
goto_programt tmp;
tmp.add_instruction(SKIP)->source_location=code.source_location();
{
// save 'leave' target
leave_targett leave_target(targets);
targets.set_leave(tmp.instructions.begin());
// first put 'finally' code onto destructor stack
targets.destructor_stack.push_back(to_code(code.op1()));
// do 'try' code
convert(to_code(code.op0()), dest);
// pop 'finally' from destructor stack
targets.destructor_stack.pop_back();
// 'leave' target gets restored here
}
// now add 'finally' code
convert(to_code(code.op1()), dest);
// this is the target for 'leave'
dest.destructive_append(tmp);
}
void c_typecheck_baset::typecheck_gcc_switch_case_range(codet &code)
{
if(code.operands().size()!=3)
{
err_location(code);
error() << "gcc_switch_case_range expected to have three operands"
<< eom;
throw 0;
}
typecheck_code(to_code(code.op2()));
if(!case_is_allowed)
{
err_location(code);
error() << "did not expect `case' here" << eom;
throw 0;
}
typecheck_expr(code.op0());
typecheck_expr(code.op1());
implicit_typecast(code.op0(), switch_op_type);
implicit_typecast(code.op1(), switch_op_type);
}
void c_typecheck_baset::typecheck_for(codet &code)
{
if(code.operands().size()!=4)
{
err_location(code);
error() << "for expected to have four operands" << eom;
throw 0;
}
// the "for" statement has an implicit block around it,
// since code.op0() may contain declarations
//
// we therefore transform
//
// for(a;b;c) d;
//
// to
//
// { a; for(;b;c) d; }
//
// if config.ansi_c.for_has_scope
if(!config.ansi_c.for_has_scope ||
code.op0().is_nil())
{
if(code.op0().is_not_nil())
typecheck_code(to_code(code.op0()));
if(code.op1().is_nil())
code.op1()=true_exprt();
else
{
typecheck_expr(code.op1());
implicit_typecast_bool(code.op1());
}
if(code.op2().is_not_nil())
typecheck_expr(code.op2());
if(code.op3().is_not_nil())
{
// save & set flags
bool old_break_is_allowed=break_is_allowed;
bool old_continue_is_allowed=continue_is_allowed;
break_is_allowed=continue_is_allowed=true;
// recursive call
if(to_code(code.op3()).get_statement()==ID_decl_block)
{
code_blockt code_block;
code_block.add_source_location()=code.op3().source_location();
code_block.move_to_operands(code.op3());
code.op3().swap(code_block);
}
typecheck_code(to_code(code.op3()));
// restore flags
break_is_allowed=old_break_is_allowed;
continue_is_allowed=old_continue_is_allowed;
}
}
else
{
code_blockt code_block;
code_block.add_source_location()=code.source_location();
if(to_code(code.op3()).get_statement()==ID_block)
code_block.set(
ID_C_end_location,
to_code_block(to_code(code.op3())).end_location());
else
code_block.set(
ID_C_end_location,
code.op3().source_location());;
code_block.reserve_operands(2);
code_block.move_to_operands(code.op0());
code.op0().make_nil();
code_block.move_to_operands(code);
code.swap(code_block);
typecheck_code(code); // recursive call
}
typecheck_spec_expr(code, ID_C_spec_loop_invariant);
}
void c_typecheck_baset::typecheck_code(codet &code)
{
if(code.id()!=ID_code)
{
err_location(code);
error() << "expected code, got " << code.pretty() << eom;
throw 0;
}
code.type()=code_typet();
const irep_idt &statement=code.get_statement();
if(statement==ID_expression)
typecheck_expression(code);
else if(statement==ID_label)
typecheck_label(to_code_label(code));
else if(statement==ID_switch_case)
typecheck_switch_case(to_code_switch_case(code));
else if(statement==ID_gcc_switch_case_range)
typecheck_gcc_switch_case_range(code);
else if(statement==ID_block)
typecheck_block(code);
else if(statement==ID_decl_block)
{
}
else if(statement==ID_ifthenelse)
typecheck_ifthenelse(to_code_ifthenelse(code));
else if(statement==ID_while)
typecheck_while(to_code_while(code));
else if(statement==ID_dowhile)
typecheck_dowhile(to_code_dowhile(code));
else if(statement==ID_for)
typecheck_for(code);
else if(statement==ID_switch)
typecheck_switch(to_code_switch(code));
else if(statement==ID_break)
typecheck_break(code);
else if(statement==ID_goto)
typecheck_goto(to_code_goto(code));
else if(statement==ID_gcc_computed_goto)
typecheck_gcc_computed_goto(code);
else if(statement==ID_continue)
typecheck_continue(code);
else if(statement==ID_return)
typecheck_return(code);
else if(statement==ID_decl)
typecheck_decl(code);
else if(statement==ID_assign)
typecheck_assign(code);
else if(statement==ID_skip)
{
}
else if(statement==ID_asm)
typecheck_asm(code);
else if(statement==ID_start_thread)
typecheck_start_thread(code);
else if(statement==ID_gcc_local_label)
typecheck_gcc_local_label(code);
else if(statement==ID_msc_try_finally)
{
assert(code.operands().size()==2);
typecheck_code(to_code(code.op0()));
typecheck_code(to_code(code.op1()));
}
else if(statement==ID_msc_try_except)
{
assert(code.operands().size()==3);
typecheck_code(to_code(code.op0()));
typecheck_expr(code.op1());
typecheck_code(to_code(code.op2()));
}
else if(statement==ID_msc_leave)
{
// fine as is, but should check that we
// are in a 'try' block
}
else if(statement==ID_static_assert)
{
assert(code.operands().size()==2);
typecheck_expr(code.op0());
typecheck_expr(code.op1());
}
else if(statement==ID_CPROVER_try_catch ||
statement==ID_CPROVER_try_finally)
{
assert(code.operands().size()==2);
typecheck_code(to_code(code.op0()));
typecheck_code(to_code(code.op1()));
}
else if(statement==ID_CPROVER_throw)
{
assert(code.operands().empty());
}
else if(statement==ID_assume ||
statement==ID_assert)
{
// These are not generated by the C/C++ parsers,
// but we allow them for the benefit of other users
// of the typechecker.
assert(code.operands().size()==1);
typecheck_expr(code.op0());
}
else
{
err_location(code);
error() << "unexpected statement: " << statement << eom;
throw 0;
}
}
void c_typecheck_baset::typecheck_decl(codet &code)
{
// this comes with 1 operand, which is a declaration
if(code.operands().size()!=1)
{
err_location(code);
error() << "decl expected to have 1 operand" << eom;
throw 0;
}
// op0 must be declaration
if(code.op0().id()!=ID_declaration)
{
err_location(code);
error() << "decl statement expected to have declaration as operand"
<< eom;
throw 0;
}
ansi_c_declarationt declaration;
declaration.swap(code.op0());
if(declaration.get_is_static_assert())
{
assert(declaration.operands().size()==2);
codet new_code(ID_static_assert);
new_code.add_source_location()=code.source_location();
new_code.operands().swap(declaration.operands());
code.swap(new_code);
typecheck_code(code);
return; // done
}
typecheck_declaration(declaration);
std::list<codet> new_code;
// iterate over declarators
for(ansi_c_declarationt::declaratorst::const_iterator
d_it=declaration.declarators().begin();
d_it!=declaration.declarators().end();
d_it++)
{
irep_idt identifier=d_it->get_name();
// look it up
symbol_tablet::symbolst::iterator s_it=
symbol_table.symbols.find(identifier);
if(s_it==symbol_table.symbols.end())
{
err_location(code);
error() << "failed to find decl symbol `" << identifier
<< "' in symbol table" << eom;
throw 0;
}
symbolt &symbol=s_it->second;
// This must not be an incomplete type, unless it's 'extern'
// or a typedef.
if(!symbol.is_type &&
!symbol.is_extern &&
!is_complete_type(symbol.type))
{
error().source_location=symbol.location;
error() << "incomplete type not permitted here" << eom;
throw 0;
}
// see if it's a typedef
// or a function
// or static
if(symbol.is_type ||
symbol.type.id()==ID_code ||
symbol.is_static_lifetime)
{
// we ignore
}
else
{
code_declt code;
code.add_source_location()=symbol.location;
code.symbol()=symbol.symbol_expr();
code.symbol().add_source_location()=symbol.location;
// add initializer, if any
if(symbol.value.is_not_nil())
{
code.operands().resize(2);
code.op1()=symbol.value;
}
new_code.push_back(code);
}
}
// stash away any side-effects in the declaration
new_code.splice(new_code.begin(), clean_code);
if(new_code.empty())
{
source_locationt source_location=code.source_location();
code=code_skipt();
code.add_source_location()=source_location;
}
else if(new_code.size()==1)
{
code.swap(new_code.front());
}
else
{
// build a decl-block
code_blockt code_block(new_code);
code_block.set_statement(ID_decl_block);
code.swap(code_block);
}
}