Method make_init_value

src/VariableSelector.cpp:817–890

* find an initializing value for a new variable * for non-pointers, we just use constants * for pointers we need to find another variable to take address with a random chance. * If no much variable is available, we have to create a suitable variable (which * might call this function again) *************************************************************************************/

 *    might call this function again)
 *************************************************************************************/
Expression*
VariableSelector::make_init_value(Effect::Access access, const CGContext &cg_context, const Type* t, const CVQualifiers* qf, Block* b)
{
	assert(qf && qf->sanity_check(t));
	CVQualifiers qfer(*qf);
	// the initialzer should always be less restricting than the variable to be initialized
	qfer.accept_stricter = false;

	if (t->eType != ePointer || rnd_flipcoin(20)) {
		ERROR_GUARD(NULL);
		if (t->eType == eSimple)
			assert(t->simple_type != eVoid);
		return Constant::make_random(t);
	}
	ERROR_GUARD(NULL);
	// for pointers, take address of a random visible local variable
	const Type* type = t->ptr_type;
	assert(type);

	vector<Variable*> vars = find_all_visible_vars(b);
	vector<const Variable*> dummy;

	Variable *var = NULL;
	// b == NULL means we are generating init for globals
	if (!b && CGOptions::ccomp()) {
		get_all_array_vars(dummy);
		var = choose_var(vars, access, cg_context, type, &qfer, eExact, dummy, true, true);
	}
	else {
		if (!CGOptions::addr_taken_of_locals())
			get_all_local_vars(b, dummy);
		var = choose_var(vars, access, cg_context, type, &qfer, eExact, dummy, true);
	}
	ERROR_GUARD(NULL);

	// if no such var, create a new one
	if (var == 0) {
		DEPTH_GUARD_BY_TYPE_RETURN(dtInitPointerValue, NULL);
		// current context has no impact on variable initialization, which happens at declare time?
		bool no_volatile = false; //!cg_context.get_effect_context().is_side_effect_free();
		if (CGOptions::strict_volatile_rule())
			no_volatile = !cg_context.get_effect_context().is_side_effect_free();
		CVQualifiers qfer_deref = qfer.random_loose_qualifiers(no_volatile, access, cg_context);
		qfer_deref.remove_qualifiers(1);
		qfer_deref.accept_stricter = false;
		bool use_local = (!CGOptions::global_variables() || (b != 0 && type->eType == ePointer && !qfer_deref.is_volatile()));
		const Type* tt = use_local ? Type::random_type_from_type(type, true, true) : Type::random_type_from_type(type, false, true);
		ERROR_GUARD(NULL);
		// create a local if it's not a volatile, and it's a pointer, and block is specified
		if (CGOptions::addr_taken_of_locals() && use_local) {
			var = GenerateNewParentLocal(*b, Effect::READ, cg_context, tt, &qfer_deref);
			ERROR_GUARD(NULL);
			Bookkeeper::record_volatile_access(var, var->type->get_indirect_level() - tt->get_indirect_level(), false);
		}
		else {
			if (CGOptions::ccomp()) {
				var = GenerateNewNonArrayGlobal(Effect::READ, cg_context, tt, &qfer_deref);
			}