#include <stdio.h>
#include <stdbool.h>
#include "cdecl.h"
#include "typemap.h"

/*
 * We can represent type specifiers as a bitmap, which gives us a finite
 * list of acceptable bitmap values according to the C standard.  However,
 * the "long" specifier is allowed to occur more than once, but only at most
 * 2 times.  Treat it as a special case, assigning an unused bit to represent
 * the second long.
 */
#define CDECL_TYPE_LLONG 31

static unsigned long add_typespec(unsigned long map, struct cdecl_declspec *s)
{
	if (s->type >= CDECL_TYPE_LLONG) {
		fprintf(stderr, "invalid type specifier\n");
		return -1;
	}

	if (s->type == CDECL_TYPE_LONG) {
		if (map & (1ul<<CDECL_TYPE_LLONG)) {
			fprintf(stderr, "too many long specifiers\n");
			return -1;
		} else if (map & (1ul<<CDECL_TYPE_LONG)) {
			return map | (1ul<<CDECL_TYPE_LLONG);
		}
	}

	if (map & (1ul<<s->type)) {
		fprintf(stderr, "duplicate type specifier\n");
		return -1;
	}

	return map | (1ul<<s->type);
}

bool cdecl__typemap_is_valid(unsigned long map)
{
	switch (map) {
#	include "validtypes.h"
		return true;
	}

	return false;
}

unsigned long cdecl__build_typemap(struct cdecl_declspec *s)
{
	unsigned long map = 0;

	for (struct cdecl_declspec *c = s; c; c = c->next) {
		if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
			continue;

		map = add_typespec(map, c);
		if (map == -1)
			break;
	}

	return map;
}