defer attempt

defer.h

#ifndef DEFER_H
#define DEFER_H

struct guard_metadata {
	int labels[32];
	size_t label_count;
	bool run_mode;
	int at;
};

#define concat(x, y)  x##y
#define concat2(x, y) concat(x, y)

#define leave                 \
	_guard_ptr->run_mode = 1; \
	continue

#define guard                                                                         \
	struct guard_metadata concat2(_guard_, __LINE__) = {{0}, 0, false, 0};            \
	struct guard_metadata *_guard_ptr = &concat2(_guard_, __LINE__);                  \
	goto concat2(_into_, __LINE__);                                                   \
	while ((_guard_ptr->run_mode = true) && _guard_ptr->at < _guard_ptr->label_count) \
		switch (_guard_ptr->labels[_guard_ptr->at])                                   \
	concat2(_into_, __LINE__) :

#define defer                                                                                                                     \
	_guard_ptr->labels[_guard_ptr->label_count++] = __LINE__;                                                                     \
	case __LINE__:                                                                                                                \
		goto concat2(_skip_bail_switch, __LINE__);                                                                                \
		concat2(_bail_switch, __LINE__) : break;                                                                                  \
		concat2(_skip_bail_switch, __LINE__) : while (_guard_ptr->run_mode) if (_guard_ptr->labels[_guard_ptr->at] != __LINE__) { \
			goto concat2(_bail_switch, __LINE__);                                                                                 \
		}                                                                                                                         \
		else if (_guard_ptr->at++, _guard_ptr->run_mode)

#endif