/*
 * Copyright © 2011, 2021, 2023-2024 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/>.
 */

#ifndef CDECL_H_
#define CDECL_H_

#include <stddef.h> /* for size_t */

#if __GNUC__
#  define CDECL__INLINE __inline
#else
#  define CDECL__INLINE inline
#endif

/* Compatibility typedefs */
#if HAVE__BOOL
typedef _Bool cdecl_bool;
#else
typedef signed char cdecl_bool;
#endif

#if HAVE_UNSIGNED_LONG_LONG_INT
typedef unsigned long long cdecl_uintmax;
#elif HAVE_UNSIGNED___INT64
typedef unsigned __int64 cdecl_uintmax;
#else
typedef unsigned long cdecl_uintmax;
#endif

/* Declaration specifier kinds. */
enum {
	CDECL_SPEC_TYPE = 256,
	CDECL_SPEC_STOR = 512,
	CDECL_SPEC_QUAL = 1024,
	CDECL_SPEC_FUNC = 2048
};

enum {
	CDECL_TYPE_VOID = CDECL_SPEC_TYPE,
	CDECL_TYPE_CHAR,
	CDECL_TYPE_SHORT,
	CDECL_TYPE_INT,
	CDECL_TYPE_LONG,
	CDECL_TYPE_FLOAT,
	CDECL_TYPE_DOUBLE,
	CDECL_TYPE_SIGNED,
	CDECL_TYPE_UNSIGNED,
	CDECL_TYPE_BOOL,
	CDECL_TYPE_COMPLEX,
	CDECL_TYPE_IMAGINARY,
	CDECL_TYPE_STRUCT,
	CDECL_TYPE_UNION,
	CDECL_TYPE_ENUM,
	CDECL_TYPE_IDENT,
	CDECL_STOR_TYPEDEF = CDECL_SPEC_STOR,
	CDECL_STOR_EXTERN,
	CDECL_STOR_STATIC,
	CDECL_STOR_AUTO,
	CDECL_STOR_REGISTER,
	CDECL_QUAL_RESTRICT = CDECL_SPEC_QUAL,
	CDECL_QUAL_VOLATILE,
	CDECL_QUAL_CONST,
	CDECL_FUNC_INLINE = CDECL_SPEC_FUNC
};

/* Declarator types. */
enum {
	CDECL_DECL_NULL,
	CDECL_DECL_IDENT,
	CDECL_DECL_POINTER,
	CDECL_DECL_ARRAY,
	CDECL_DECL_FUNCTION
};

struct cdecl {
	struct cdecl *next;

	struct cdecl_declspec {
		struct cdecl_declspec *next;
		unsigned type;
		char *ident;
	} *specifiers;

	struct cdecl_declarator {
		struct cdecl_declarator *child;
		unsigned type;
		union {
			char *ident;
			struct cdecl_pointer {
				struct cdecl_declspec *qualifiers;
			} pointer;
			struct cdecl_array {
				char *vla;
				cdecl_uintmax length;
			} array;
			struct cdecl_function {
				struct cdecl *parameters;
				cdecl_bool variadic;
			} function;
		} u;
	} *declarators;
};

struct cdecl *cdecl_parse_decl(const char *declstr);
struct cdecl *cdecl_parse_english(const char *english);
void cdecl_free(struct cdecl *decl);

size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl);
size_t cdecl_declare(char *buf, size_t n, struct cdecl *decl);

static CDECL__INLINE int cdecl_spec_kind(const struct cdecl_declspec *spec)
{
	return spec->type & ~(CDECL_SPEC_TYPE-1u);
}

static CDECL__INLINE int cdecl_is_abstract(const struct cdecl_declarator *d)
{
	while (d->child)
		d = d->child;

	return d->type != CDECL_DECL_IDENT;
}

/* Error handling. */
enum {
	CDECL_ENOMEM = 1,
	CDECL_ENOPARSE,

	/* Obsolete error codes (no longer returned by the library) */
	CDECL_EBADARRAY,
	CDECL_EBADDECL,
	CDECL_EBADPARAMS,
	CDECL_EBADPOINTER,
	CDECL_EBADQUAL,
	CDECL_EBADRETURN,
	CDECL_EBADSTOR,
	CDECL_EBADTYPE,
	CDECL_ENOTFUNC,
	CDECL_EVOIDPARAM
};

struct cdecl_error {
	unsigned code;
	const char *str;
};

const struct cdecl_error *cdecl_get_error(void);

#endif