/* Simple subrs.

   Copyright (C) 2019-2023 Free Software Foundation, Inc.

   This file is part of libctf.

   libctf 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, 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; see the file COPYING.  If not see

   <http://www.gnu.org/licenses/>.  */

#include <ctf-impl.h>

#ifdef HAVE_MMAP

#include <sys/mman.h>

#endif

#include <sys/types.h>

#include <stdarg.h>

#include <string.h>

#include <unistd.h>

#ifndef ENOTSUP

#define ENOTSUP ENOSYS

#endif

int _libctf_version = CTF_VERSION;        /* Library client version.  */

int _libctf_debug = 0;            /* Debugging messages enabled.  */

/* Private, read-only mmap from a file, with fallback to copying.

   No handling of page-offset issues at all: the caller must allow for that. */

_libctf_malloc_ void *

ctf_mmap (size_t length, size_t offset, int fd)

{

  void *data;

#ifdef HAVE_MMAP

  data = mmap (NULL, length, PROT_READ, MAP_PRIVATE, fd, offset);

  if (data == MAP_FAILED)

    data = NULL;

#else

  if ((data = malloc (length)) != NULL)

    {

      if (ctf_pread (fd, data, length, offset) <= 0)

  {

    free (data);

    data = NULL;

  }

    }

#endif

  return data;

}

void

ctf_munmap (void *buf, size_t length _libctf_unused_)

{

#ifdef HAVE_MMAP

  (void) munmap (buf, length);

#else

  free (buf);

#endif

}

ssize_t

ctf_pread (int fd, void *buf, ssize_t count, off_t offset)

{

  ssize_t len;

  size_t acc = 0;

  char *data = (char *) buf;

#ifdef HAVE_PREAD

  while (count > 0)

    {

      errno = 0;

      if (((len = pread (fd, data, count, offset)) < 0) &&

    errno != EINTR)

    return len;

      if (errno == EINTR)

  continue;

      acc += len;

      if (len == 0)       /* EOF.  */

  return acc;

      count -= len;

      offset += len;

      data += len;

    }

  return acc;

#else

  off_t orig_off;

  if ((orig_off = lseek (fd, 0, SEEK_CUR)) < 0)

    return -1;

  if ((lseek (fd, offset, SEEK_SET)) < 0)

    return -1;

  while (count > 0)

    {

      errno = 0;

      if (((len = read (fd, data, count)) < 0) &&

    errno != EINTR)

    return len;

      if (errno == EINTR)

  continue;

      acc += len;

      if (len == 0)       /* EOF.  */

  break;

      count -= len;

      data += len;

    }

  if ((lseek (fd, orig_off, SEEK_SET)) < 0)

    return -1;          /* offset is smashed.  */

#endif

  return acc;

}

/* Set the CTF library client version to the specified version.  If version is

   zero, we just return the default library version number.  */

int

ctf_version (int version)

{

  if (version < 0)

    {

      errno = EINVAL;

      return -1;

    }

  if (version > 0)

    {

      /*  Dynamic version switching is not presently supported. */

      if (version != CTF_VERSION)

  {

    errno = ENOTSUP;

    return -1;

  }

      ctf_dprintf ("ctf_version: client using version %d\n", version);

      _libctf_version = version;

    }

  return _libctf_version;

}

void

libctf_init_debug (void)

{

  static int inited;

  if (!inited)

    {

      _libctf_debug = getenv ("LIBCTF_DEBUG") != NULL;

      inited = 1;

    }

}

void ctf_setdebug (int debug)

{

  /* Ensure that libctf_init_debug() has been called, so that we don't get our

     debugging-on-or-off smashed by the next call.  */

  libctf_init_debug();

  _libctf_debug = debug;

  ctf_dprintf ("CTF debugging set to %i\n", debug);

}

int ctf_getdebug (void)

{

  return _libctf_debug;

}

_libctf_printflike_ (1, 2)

void ctf_dprintf (const char *format, ...)

{

  if (_libctf_unlikely_ (_libctf_debug))

    {

      va_list alist;

      va_start (alist, format);

      fflush (stdout);

      (void) fputs ("libctf DEBUG: ", stderr);

      (void) vfprintf (stderr, format, alist);

      va_end (alist);

    }

}

/* This needs more attention to thread-safety later on.  */

static ctf_list_t open_errors;

/* Errors and warnings.  Report the warning or error to the list in FP (or the

   open errors list if NULL): if ERR is nonzero it is the errno to report to the

   debug stream instead of that recorded on fp.  */

_libctf_printflike_ (4, 5)

extern void

ctf_err_warn (ctf_dict_t *fp, int is_warning, int err,

        const char *format, ...)

{

  va_list alist;

  ctf_err_warning_t *cew;

  /* Don't bother reporting errors here: we can't do much about them if they

     happen.  If we're so short of memory that a tiny malloc doesn't work, a

     vfprintf isn't going to work either and the caller will have to rely on the

     ENOMEM return they'll be getting in short order anyway.  */

  if ((cew = malloc (sizeof (ctf_err_warning_t))) == NULL)

    return;

  cew->cew_is_warning = is_warning;

  va_start (alist, format);

  if (vasprintf (&cew->cew_text, format, alist) < 0)

    {

      free (cew);

      va_end (alist);

      return;

    }

  va_end (alist);

  /* Include the error code only if there is one; if this is not a warning,

     only use the error code if it was explicitly passed and is nonzero.

     (Warnings may not have a meaningful error code, since the warning may not

     lead to unwinding up to the user.)  */

  if ((!is_warning && (err != 0 || (fp && ctf_errno (fp) != 0)))

      || (is_warning && err != 0))

    ctf_dprintf ("%s: %s (%s)\n", is_warning ? _("error") : _("warning"),

     cew->cew_text, err != 0 ? ctf_errmsg (err)

     : ctf_errmsg (ctf_errno (fp)));

  else

    ctf_dprintf ("%s: %s\n", is_warning ? _("error") : _("warning"),

     cew->cew_text);

  if (fp != NULL)

    ctf_list_append (&fp->ctf_errs_warnings, cew);

  else

    ctf_list_append (&open_errors, cew);

}

/* Move all the errors/warnings from an fp into the open_errors.  */

void

ctf_err_warn_to_open (ctf_dict_t *fp)

{

  ctf_list_splice (&open_errors, &fp->ctf_errs_warnings);

}

/* Error-warning reporting: an 'iterator' that returns errors and warnings from

   the error/warning list, in order of emission.  Errors and warnings are popped

   after return: the caller must free the returned error-text pointer.

   An fp of NULL returns CTF-open-time errors from the open_errors variable

   above.

   The treatment of errors from this function itself is somewhat unusual: it

   will often be called on an error path, so we don't want to overwrite the

   ctf_errno unless we have no choice.  So, like ctf_bufopen et al, this

   function takes an errp pointer where errors are reported.  The pointer is

   optional: if not set, errors are reported via the fp (if non-NULL).  Calls

   with neither fp nor errp set are mildly problematic because there is no clear

   way to report end-of-iteration: you just have to assume that a NULL return

   means the end, and not an iterator error.  */

char *

ctf_errwarning_next (ctf_dict_t *fp, ctf_next_t **it, int *is_warning,

         int *errp)

{

  ctf_next_t *i = *it;

  char *ret;

  ctf_list_t *errlist;

  ctf_err_warning_t *cew;

  if (fp)

    errlist = &fp->ctf_errs_warnings;

  else

    errlist = &open_errors;

  if (!i)

    {

      if ((i = ctf_next_create ()) == NULL)

  {

    if (errp)

      *errp = ENOMEM;

    else if (fp)

      ctf_set_errno (fp, ENOMEM);

    return NULL;

  }

      i->cu.ctn_fp = fp;

      i->ctn_iter_fun = (void (*) (void)) ctf_errwarning_next;

      *it = i;

    }

  if ((void (*) (void)) ctf_errwarning_next != i->ctn_iter_fun)

    {

      if (errp)

  *errp = ECTF_NEXT_WRONGFUN;

      else if (fp)

  ctf_set_errno (fp, ECTF_NEXT_WRONGFUN);

      return NULL;

    }

  if (fp != i->cu.ctn_fp)

    {

      if (errp)

  *errp = ECTF_NEXT_WRONGFP;

      else if (fp)

  ctf_set_errno (fp, ECTF_NEXT_WRONGFP);

      return NULL;

    }

  cew = ctf_list_next (errlist);

  if (!cew)

    {

      ctf_next_destroy (i);

      *it = NULL;

      if (errp)

  *errp = ECTF_NEXT_END;

      else if (fp)

  ctf_set_errno (fp, ECTF_NEXT_END);

      return NULL;

    }

  if (is_warning)

    *is_warning = cew->cew_is_warning;

  ret = cew->cew_text;

  ctf_list_delete (errlist, cew);

  free (cew);

  return ret;

}

void

ctf_assert_fail_internal (ctf_dict_t *fp, const char *file, size_t line,

        const char *exprstr)

{

  ctf_err_warn (fp, 0, ECTF_INTERNAL, _("%s: %lu: libctf assertion failed: %s"),

    file, (long unsigned int) line, exprstr);

  ctf_set_errno (fp, ECTF_INTERNAL);

}