1  /* Determine number of screen columns needed for a size-bounded wide string.
       2     Copyright (C) 1999, 2011-2023 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 1999.
       4  
       5     This file is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU Lesser General Public License as
       7     published by the Free Software Foundation; either version 2.1 of the
       8     License, or (at your option) any later version.
       9  
      10     This file is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13     GNU Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  int
      19  FUNC (const UNIT *s, size_t n)
      20  {
      21    int count = 0;
      22    for (; n > 0; s++, n--)
      23      {
      24        UNIT c = *s;
      25        if (c == (UNIT)'\0')
      26          break;
      27        {
      28          int width = CHARACTER_WIDTH (c);
      29          if (width < 0)
      30            goto found_nonprinting;
      31          if (width > INT_MAX - count)
      32            goto overflow;
      33          count += width;
      34        }
      35      }
      36    return count;
      37  
      38    /* The total width has become > INT_MAX.
      39       Continue searching for a non-printing wide character.  */
      40    for (; n > 0; s++, n--)
      41      {
      42        UNIT c = *s;
      43        if (c == (UNIT)'\0')
      44          break;
      45        {
      46          int width = CHARACTER_WIDTH (c);
      47          if (width < 0)
      48            goto found_nonprinting;
      49        }
      50       overflow: ;
      51      }
      52    return INT_MAX;
      53  
      54   found_nonprinting:
      55    return -1;
      56  }