[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Dynamic loading progress

From: Paul Eggert
Subject: Re: Dynamic loading progress
Date: Fri, 20 Nov 2015 12:47:59 -0800
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0

Philipp Stephani wrote:
This member will typically be used as follows:

if (env->size >= sizeof *env) {
   // good, object is at least as big as expected
} else {
   // Emacs is too old

I'm leery of recommending this sort of checking. In practice incompatible structure layout changes so often involve something more than merely extending a structure, that a size check is not worth the trouble; you really want a version check. I might be persuaded that it's a good idea if I saw some code doing it effectively, but currently there is no such code in the Emacs sources (the module test function doesn't check sizes -- why not?).

reply via email to

[Prev in Thread] Current Thread [Next in Thread]