#include <stdlib.h>
#include "dynamic_typing.h"

struct entry {
    void *start;
    void *end;
    struct type *type;
};

static struct entry *ENTRIES;
static unsigned long N_ENTRIES;

void annotate_type(void *ptr, struct type *type) {
    ENTRIES = realloc(ENTRIES, (++N_ENTRIES) * sizeof(ENTRIES[0]));
    ENTRIES[N_ENTRIES - 1] = (struct entry){
        .start = ptr,
        .end = ptr + 1,
        .type = type,
    };
}

struct type *dynamic_typeof(void *ptr) {
    for (unsigned long i = N_ENTRIES; i --> 0;)
        if (ENTRIES[i].start <= ptr && ptr < ENTRIES[i].end)
            return ENTRIES[i].type;
    return 0;
}

struct type *make_basic(const char *type, unsigned long size) {
    struct type *t = calloc(1, sizeof(*t));
    t->kind = TY_BASIC;
    t->basic = type;
    t->size = size;
    return t;
}

struct type *make_array(struct type *base, unsigned long len) {
    struct type *t = calloc(1, sizeof(*t));
    t->kind = TY_ARRAY;
    t->base = base;
    t->length = len;
    t->size = len * t->base->size;
    return t;
}

struct type *make_pointer(struct type *base) {
    struct type *t = calloc(1, sizeof(*t));
    t->kind = TY_POINTER;
    t->base = base;
    t->size = sizeof(void*);
    return t;
}

// function not supported yet
// for struct & union, the members are initialized by the caller
struct type *make_struct(unsigned long size) {
    struct type *t = calloc(1, sizeof(*t));
    t->kind = TY_STRUCT;
    return t;
}

struct type *make_union(unsigned long size) {
    struct type *t = calloc(1, sizeof(*t));
    t->kind = TY_UNION;
    return t;
}
void prepend_member(struct type *aggregate, struct type *member, const char *name, unsigned long offset) {
    member->offset = offset;
    member->next_member = aggregate->members;
    member->field_name = name;
    aggregate->members = member;
}