Al 03/03/13 21:52, En/na Sven Barth ha escrit: > On 03.03.2013 20:32, Luca Olivetti wrote: >> Al 03/03/13 14:34, En/na Sven Barth ha escrit: >> >>> For "packed" there is the >>> guarantee though that the layout will stay the same. >> >> Are you sure? Does the same guarantee apply to bitpacked? >> Lately I've become lazy, and instead of manually decoding data (bits, >> bytes, words) read from a device, I'm relying on packed/bitpacked >> records, but I wasn't sure that upgrading the compiler wouldn't break my >> code. > > For "packed" it is guaranteed (*), because this is the whole purpose of > this modifier, for "bitpacked" it is not. It just tells the compiler to > pack the record as densly as possible, but depending on the platform > this might not be possible.
At the moment I don't care about the platform, only about different (newer) versions of the compiler. Currently , with 2.6.0, bitpacked under win32 gives me the correct layout (I have to adjust endianness for words/dwords but individual bit fields are where they should be). Can I be sure that 2.6.2 (and later version) won't break my code? Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es Tel. +34 935883004 Fax +34 935883007 -- _______________________________________________ Lazarus mailing list [email protected] http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
