/*
 *  Parse and validate C declarations.
 *  Copyright © 2011 Nick Bowler
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <stdio.h>
#include <assert.h>

#include "cdecl.h"
#include "typemap.h"
#include "parse.h"
#include "scan.h"

static int verify_declspecs(struct cdecl_declspec *s)
{
	unsigned num_storage = 0;
	unsigned long typemap;

	typemap = cdecl__build_typemap(s);
	if (typemap == -1)
		return -1;

	for (struct cdecl_declspec *c = s; c; c = c->next) {
		switch (cdecl_spec_kind(c)) {
		case CDECL_SPEC_TYPE:
			continue;
		case CDECL_SPEC_STOR:
			if (++num_storage > 1) {
				fprintf(stderr, "too many storage-class specifiers\n");
				return -1;
			}
			break;
		case CDECL_SPEC_QUAL:
			/*
			 * Restrict qualifiers are only valid in the
			 * pointer qualifier list, which isn't checked here.
			 */
			if (c->type == CDECL_QUAL_RESTRICT) {
				fprintf(stderr, "only pointer types can be restrict-qualified.\n");
				return -1;
			}
			break;
		case CDECL_SPEC_FUNC:
			/*
			 * We don't support functions yet.
			 */
			fprintf(stderr, "only function declarations may have function specifiers.\n");
			return -1;
		default:
			assert(0);
		}
	}

	return 0;
}

static int verify_decl(struct cdecl *decl)
{
	return verify_declspecs(decl->specifiers);
}

struct cdecl *cdecl_parse_decl(const char *declstr)
{
	YY_BUFFER_STATE state;
	struct cdecl *decl;
	int rc;

	state = yy_scan_string(declstr);
	rc = yyparse(&decl);
	yy_delete_buffer(state);

	if (rc != 0)
		return NULL;

	rc = verify_decl(decl);
	if (rc != 0) {
		cdecl_free(decl);
		return NULL;
	}

	return decl;
}