/*
 * Copyright © 2025, Niklas Haas
 * Copyright © 2018, VideoLAN and dav1d authors
 * Copyright © 2018, Two Orioles, LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef CHECKASM_PLATFORM_AARCH64_H
#define CHECKASM_PLATFORM_AARCH64_H

#include "checkasm/attributes.h"
#include "checkasm/checkasm.h"
#include <stdint.h>

CHECKASM_API void checkasm_checked_call(void *func, ...);

/* The upper 32 bits of 32-bit data types are undefined when passed as function
 * parameters. In practice those bits usually end up being zero which may hide
 * certain bugs, such as using a register containing undefined bits as a pointer
 * offset, so we want to intentionally clobber those bits with junk to expose
 * any issues. The following set of macros automatically calculates a bitmask
 * specifying which parameters should have their upper halves clobbered. */
/* Up to 8 floating-point parameters are passed in float registers, which are
 * handled orthogonally from integer parameters passed in GPR registers. */
#define IGNORED_FP_ARGS 8

#if CHECKASM_HAVE_GENERIC
  #define clobber_type(arg)                                                              \
      _Generic((void (*)(void *, arg)) NULL,                                             \
          void (*)(void *, int32_t): clobber_mask |= 1 << mpos++,                        \
          void (*)(void *, uint32_t): clobber_mask |= 1 << mpos++,                       \
          void (*)(void *, float): mpos += (fp_args++ >= IGNORED_FP_ARGS),               \
          void (*)(void *, double): mpos += (fp_args++ >= IGNORED_FP_ARGS),              \
          default: mpos++)

  #define init_clobber_mask(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, ...)            \
      unsigned clobber_mask = 0;                                                         \
      {                                                                                  \
          int mpos = 0, fp_args = 0;                                                     \
          clobber_type(a);                                                               \
          clobber_type(b);                                                               \
          clobber_type(c);                                                               \
          clobber_type(d);                                                               \
          clobber_type(e);                                                               \
          clobber_type(f);                                                               \
          clobber_type(g);                                                               \
          clobber_type(h);                                                               \
          clobber_type(i);                                                               \
          clobber_type(j);                                                               \
          clobber_type(k);                                                               \
          clobber_type(l);                                                               \
          clobber_type(m);                                                               \
          clobber_type(n);                                                               \
          clobber_type(o);                                                               \
      }
#else
  /* Skip parameter clobbering on compilers without support for _Generic() */
  #define init_clobber_mask(...) unsigned clobber_mask = 0
#endif

#define checkasm_declare_impl(ret, ...)                                                  \
    ret (*checked_call)(__VA_ARGS__, int64_t, int64_t, int64_t, int64_t, int64_t,        \
                        int64_t, int64_t, int64_t, int64_t, int64_t, int64_t, int64_t,   \
                        int64_t, int64_t, int64_t, int64_t, void *, unsigned)            \
        = (ret (*)(__VA_ARGS__, int64_t, int64_t, int64_t, int64_t, int64_t, int64_t,    \
                   int64_t, int64_t, int64_t, int64_t, int64_t, int64_t, int64_t,        \
                   int64_t, int64_t, int64_t, void *,                                    \
                   unsigned))(void *) checkasm_checked_call;                             \
    init_clobber_mask(__VA_ARGS__, void *, void *, void *, void *, void *, void *,       \
                      void *, void *, void *, void *, void *, void *, void *, void *)

#define checkasm_call_checked(func, ...)                                                 \
    (checkasm_set_signal_handler_state(1),                                               \
     checked_call(__VA_ARGS__, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,     \
                  func, clobber_mask));                                                  \
    checkasm_set_signal_handler_state(0)

/* ARM doesn't benefit from anything more than 16-byte alignment. */
#define CHECKASM_ALIGNMENT 16

#endif /* CHECKASM_PLATFORM_AARCH64_H */
