#include <stddef.h>
#include <alloca.h>

struct obj_symbol
{
	struct obj_symbol *next;
	unsigned int size;
};

struct common_entry
{
	struct common_entry *next;
	struct obj_symbol *sym;
};

extern void do_something(struct obj_symbol *sym);

void obj_allocate_commons(struct obj_symbol *sym)
{
	struct common_entry *common_head = NULL;

	for (; sym ; sym = sym->next) {
		struct common_entry **p, *n;
		for (p = &common_head; *p ; p = &(*p)->next)
			if (sym->size <= (*p)->sym->size)
				break;

		n = alloca(sizeof(*n));
		n->next = *p;
		n->sym = sym;
		*p = n;
	}

	{
		struct common_entry *p;
		for (p = common_head; p ; p = p->next)
			do_something(p->sym);
	}
}