/*
 * Internal declarations for libcdecl.
 * Copyright © 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 <https://www.gnu.org/licenses/>.
 */
#ifndef CDECL_INTERNAL_H_
#define CDECL_INTERNAL_H_

#include <stddef.h>
#include <gettext.h>
#include "cdecl.h"

#define MIN(a, b) ((a) < (b) ? (a) : (b))

#define _(s) dgettext(PACKAGE, s)
#define N_(s) s

/* Pack the 4 "kind" bits of a valid cdecl specifier value into two bits. */
#define PACK_KIND(x) ((( ((x>>8) - ((x)>>11)) ) >> 1) & 3)

/* Expand a packed "kind" to its original value. */
#define UNPACK_KIND(x) (0x100 << (x))

/*
 * Pack a valid cdecl specifier value (CDECL_TYPE_xxx, CDECL_STOR_xxx, etc.)
 * into 8 bits.  We do this by encoding the specifier kind in the upper two
 * bits, and the enumerated sequence in the lower 6 bits. */
#define PACK_SPEC(x) (((x) & 0x3f) | (PACK_KIND(x) << 6))

/*
 * Expand a packed specifier to its original value.
 */
#define UNPACK_SPEC(x) (UNPACK_KIND((x) >> 6) | ((x) & 0x3f))

/*
 * Pack a parser token into 7 bits.
 *
 * Bison normally numbers user-defined tokens sequentially starting from 258.
 * If api.token,raw is used, then the numbering starts from 3.  As we have
 * about 50 tokens, the latter case will fit in 7 bits easily; in the former
 * case the upper bits are constant so we don't need to store them.
 */
#define PACK_TOKEN(x) ((x) & 0x7f)

/*
 * Expand a packed token to its original value.
 */
#define UNPACK_TOKEN(x) ((x) | ((T_IDENT > 256) << 8))

struct cdecl_error;
struct cdecl_declspec;

#if ENABLE_NLS
void cdecl__init_i18n(void);
#else
static inline void cdecl__init_i18n(void)
{
}
#endif

void cdecl__err(const char *fmt, const char *arg);
void cdecl__errmsg(unsigned msg);

struct cdecl_declspec *cdecl__normalize_specs(struct cdecl_declspec *specs);

struct output_state {
	char *dst;
	size_t dstlen;
	size_t accum;
};

size_t cdecl__advance(struct output_state *dst, size_t amount);
size_t cdecl__emit(struct output_state *dst, const char *src);
size_t cdecl__emit_uint(struct output_state *dst, cdecl_uintmax val);
size_t cdecl__strlcpy(char *dst, const char *src, size_t len);

const char *cdecl__emit_specs(struct output_state *dst,
                              struct cdecl_declspec *s,
                              unsigned mask);

/*
 * If s is a (len bytes long) string corresponding to a declaration
 * specifier, then:
 *
 *   - bits 7:0 (LSB) of the return value is the packed specifier type, and
 *   - bits 15:8 of the return value is the packed parser token.
 *
 * Otherwise, if english_mode is nonzero and s is an "english keyword",
 * returns the appropriate packed parser token in bits 15:8.
 *
 * Otherwise, PACK_TOKEN(T_IDENT) is returned in bits 15:8.
 */
unsigned cdecl__to_keyword(const char *s, int len, int english_mode);

/* Container for an allocated parser token's value */
struct parse_item {
	union {
		struct cdecl_declarator declarator;
		struct cdecl_declspec   declspec;
		struct cdecl            decl;
	} u;

	char s[FLEXIBLE_ARRAY_MEMBER];
};

struct parse_item *cdecl__alloc_item(size_t s_sz);

/*
 * GCC enables -finline-small-functions in most optimization modes; this works
 * on a highlevel estimate of how big a function actually is and occasionally
 * this produces really bad results.
 *
 * While old versions of GCC do not support this attribute the result seems
 * to be merely a warning so hopefully we can get away with this check and
 * save a configure test.
 */
#ifndef CDECL__NOINLINE
#  if __GNUC__
#    define CDECL__NOINLINE __attribute__((__noinline__))
#  else
#    define CDECL__NOINLINE /**/
#  endif
#endif

/*
 * Build-time hook for white-box testing of memory allocation behaviour.
 */
#if TEST_MALLOC_HOOK
void *test_realloc_hook(void *, size_t);

static inline void *test_wrap_malloc(size_t n)
{
	return test_realloc_hook(0, n);
}

static inline void test_wrap_free(void *p)
{
	test_realloc_hook(p, 0);
}

#undef  realloc
#define realloc test_realloc_hook
#undef  malloc
#define malloc test_wrap_malloc
#undef  free
#define free test_wrap_free
#endif

#endif