Re: [AC21.5R21.4] Patch: fix cut & past problem on 64 bit platforms

SJT> + generally make long be a 64-bit quantity while while it's 32 bits on You have a double-trouble typo above. SJT> + 32-bit platforms. SJT> + SJT> + This means that on all platforms the wire item is the same size as our SJT> + buffer unit when format == 8 or format == 16 or format == wordsize == 32, SJT> + and the buffer size can be taken as bytes_remaining plus padding. SJT> + However, when format == 32 and wordsize == 64, the buffer unit is twice SJT> + the size of the wire item. Obviously this code below is not 128-bit SJT> + safe. (We could replace the factor 2 with (sizeof(long)*8/32.) Instead of "we could" why not actually use the more meaningful symbolic expression? SJT> + We can hope it doesn't much matter on versions of X11 earlier than R7. SJT> + */ SJT> + if (sizeof(long) == 8 && *actual_format_ret == 32) SJT> + total_size = 2 * bytes_remaining + 1; SJT> + else SJT> + total_size = bytes_remaining + 1; SJT> *data_ret = xnew_rawbytes (total_size); I hate this kind of code. Make sure there's enough configury infrastructure to define the stdint.h types uint16_t uint32_t uint64_t (i.e. config.h should either include stdint.h or go and define these types in the obvious way) and then in x-select.c one should have code more like (code sketch only) Lisp_Object uint32_t_to_lisp (uint32_t x) { return ((EMACS_UINT) x <= (EMACS_UINT) EMACS_INT_MAX) ? make_int (x) : Fcons (make_int (item >> 16), make_int (item & 0xffff)); } static Lisp_Object selection_data_to_lisp_data (struct device *d, Extbyte *data, size_t size, Atom type, int format) { int nitems = size / format; if (nitems == 1) { ... else if (format == 32) return uint32_t_to_lisp (* ((uint32_t *) data)); else if (format == 16) return make_int ((int) (* ((uint16_t *) data))); } else { ... } } Yes, it's a fair amount of work to do this right. Martin _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://calypso.tux.org/cgi-bin/mailman/listinfo/xemacs-beta