Hello, On Fri, Sep 23, 2022 at 07:08:26AM +0200, Peter Kovacs wrote:
> Hi all, > > We cast int to (void*) -> (example in main/sw/source/ui/fldui/changedb.cxx > line 234) > > In general this sounds like not a sane idea to me, see discussions [1] [2] > [3]. The solution that the c++ community found is the use of intptr_t, which > is defined in C99. > > In general I would like to get rid of these casts. However as a quick fix it > would make sense to use intptr_t as a first measure. IMHO casting int to void* is not as bad as it seems. Your cited sources explains that there would be problems with _round-tripping_ i.e. using an int type to pass a pointer. The reason is that on some architectures pointers (void*) are represented with more bits than integers. Notable example: Linux on x86_64. As long as we are using pointers as ``general purpose integers'' we should have no problems because they are ``big enough'' to contain any integer value _and_ any pointer. > Is there any reason that would block the move to C99? I guess C99 should be > supported by all the compilers we require . (c11 is currently not available > on all Plattforms we support.) Unfortunately, Visual Studio 2008 does not support C99. Specifically for this case, it is missing the definition of the intptr_t type. Wikipedia [4] gives more information about C99 support in Visual Studio. I hope this helps. > [1] > https://stackoverflow.com/questions/26805461/why-do-i-get-cast-from-pointer-to-integer-of-different-size-error > > [2] > https://stackoverflow.com/questions/25381610/cast-int-to-pointer-why-cast-to-long-first-as-in-p-void-42 > > [3] > https://stackoverflow.com/questions/6326338/why-when-to-use-intptr-t-for-type-casting-in-c [4] https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B#C -- Arrigo --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@openoffice.apache.org For additional commands, e-mail: dev-h...@openoffice.apache.org
