/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â Copyright 2022 Justine Alexandra Roberts Tunney                              â
â                                                                              â
â Permission to use, copy, modify, and/or distribute this software for         â
â any purpose with or without fee is hereby granted, provided that the         â
â above copyright notice and this permission notice appear in all copies.      â
â                                                                              â
â THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                â
â WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                â
â WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             â
â AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         â
â DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        â
â PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               â
â TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             â
â PERFORMANCE OF THIS SOFTWARE.                                                â
ââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââ*/
#include "ape/sections.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/calls/struct/siginfo.h"
#include "libc/calls/ucontext.h"
#include "libc/intrin/likely.h"
#include "libc/math.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/sa.h"

#ifdef __x86_64__

privileged void __sigenter_wsl(int sig, struct siginfo *info, ucontext_t *ctx) {
  int i, rva, flags;
  rva = __sighandrvas[sig & (NSIG - 1)];
  if (rva >= kSigactionMinRva) {
    flags = __sighandflags[sig & (NSIG - 1)];
    // WSL1 doesn't set the fpregs field.
    // https://github.com/microsoft/WSL/issues/2555
    if ((flags & SA_SIGINFO) && UNLIKELY(!ctx->uc_mcontext.fpregs)) {
      ctx->uc_mcontext.fpregs = &ctx->__fpustate;
      for (i = 0; i < 8; ++i) {
        long double nan = NAN;
        memcpy(ctx->__fpustate.st + i, &nan, 16);
      }
    }
    ((sigaction_f)(__executable_start + rva))(sig, info, ctx);
  }
}

#endif /* __x86_64__ */
