On Dec 8 01:43, Mark Geisert wrote: > Takashi Yano wrote: > [...] > > I think the following patch makes the intent clearer. > > What do you think? > > > > > > From d0aee9af225384a24ac6301f987ce2e94f262500 Mon Sep 17 00:00:00 2001 > > From: Takashi Yano <takashi.y...@nifty.ne.jp> > > Date: Wed, 8 Dec 2021 17:06:03 +0900 > > Subject: [PATCH] Cygwin: clipboard: Make intent of the code clearer. > > > > --- > > winsup/cygwin/fhandler_clipboard.cc | 4 ++-- > > winsup/cygwin/include/sys/clipboard.h | 1 + > > 2 files changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/winsup/cygwin/fhandler_clipboard.cc > > b/winsup/cygwin/fhandler_clipboard.cc > > index 05f54ffb3..65a3cad97 100644 > > --- a/winsup/cygwin/fhandler_clipboard.cc > > +++ b/winsup/cygwin/fhandler_clipboard.cc > > @@ -76,7 +76,7 @@ fhandler_dev_clipboard::set_clipboard (const void *buf, > > size_t len) > > clipbuf->cb_sec = clipbuf->ts.tv_sec; > > #endif > > clipbuf->cb_size = len; > > - memcpy (&clipbuf[1], buf, len); // append user-supplied data > > + memcpy (clipbuf->data, buf, len); // append user-supplied data > > GlobalUnlock (hmem); > > EmptyClipboard (); > > @@ -229,7 +229,7 @@ fhandler_dev_clipboard::read (void *ptr, size_t& len) > > if (pos < (off_t) clipbuf->cb_size) > > { > > ret = (len > (clipbuf->cb_size - pos)) ? clipbuf->cb_size - pos : len; > > - memcpy (ptr, (char *) (clipbuf + 1) + pos, ret); > > + memcpy (ptr, clipbuf->data + pos, ret); > > pos += ret; > > } > > } > > diff --git a/winsup/cygwin/include/sys/clipboard.h > > b/winsup/cygwin/include/sys/clipboard.h > > index 4c00c8ea1..b2544be85 100644 > > --- a/winsup/cygwin/include/sys/clipboard.h > > +++ b/winsup/cygwin/include/sys/clipboard.h > > @@ -44,6 +44,7 @@ typedef struct > > }; > > }; > > uint64_t cb_size; // 8 bytes everywhere > > + char data[]; > > } cygcb_t; > > #endif > > Sigh. I guess it's not possible to keep rid of a data item like I'd hoped. > At least "data[]" is cleaner than the historical "data[1]" here. If you > call the item cb_data I can live with it. > Thanks all for the discussion.
sometype *ptr; ptr = (sometype *) somebuffer; do_something (ptr + 1); is a perfectly valid and perfectly readable thing, and used a lot if "sometype" is either a header in a buffer followed by arbitrary data, or if the buffer consists of multiple packed blocks of type "sometype". Takashi's suggestion adds the information that "sometype" is a header followed by arbitrary data, so that's a good thing.. Corinna