bug#20862: 25.0.50; 32-bit Emacs configured --with-wide-int miscompiles CL

[Paul Eggert]

Eli Zaretskii wrote:
> I think the *.elc files should be reproducible, yes.  Otherwise, it's
> hard to know if there's some subtle problem in the byte compiler or
> its support routines.

The simplest fix would be to initialize cl--gensym-counter to 0, as is done in 
Common Lisp, so that Emacs generates reproducible output.  However, the 
documentation for cl-gensym says this:

(Internally, the variable @code{cl--gensym-counter} holds the counter
used to generate names.  It is incremented after each use.  In Common
Lisp this is initialized with 0, but this package initializes it with
a random time-dependent value to avoid trouble when two files that
each used @code{cl-gensym} in their compilation are loaded together.
Uninterned symbols become interned when the compiler writes them out
to a file and the Emacs loader loads them, so their names have to be
treated a bit more carefully than in Common Lisp where uninterned
symbols remain uninterned after loading.)


This passage is dismaying, as it suggests that it's a matter of luck as to 
whether trouble is avoided when two files that each used cl-gensym are loaded 
together.  I guess the trouble that's avoided is the usual issue with macro 
capture.  (Maybe we should file another bug report for this....)