[Issue 2029] Typesafe variadic functions don't work in CTFE

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=2029



--- Comment #5 from Tomas Lindquist Olsen <tomas at famolsen.dk> 2009-11-18 03:46:13 PST ---
I've attached a draft patch that replaces the typesafe variadic ast rewrites to
something that works in any scope (and with ctfe).

without the patch the following function:

    void foo(int[] arr ...)

when called:

    foo(1,2,3);

is rewritten as:

    int[3] _args;
    (_args[0] = 1, _args[1] = 2, _args[2] = 3, foo(_args[]));

..

In global scope, this breaks, as you cannot assign to globals from ctfe, and in
normal ctfe, breaks somehow as well.

This patch changes the rewrite to:

    foo([1,2,3]);

with each element being implicitly converted to the array element type.

One downside is that codegen always allocates array literals on the heap, so it
degrades performance a bit, but that needs to be fixed for
http://d.puremagic.com/issues/show_bug.cgi?id=2356 as well (though it's
probably a slightly different issue), and generally I'm not getting an
impression that it's a concern (performance is secondary).

In any case I added a new "scopedLiteral" field to ArrayLiteralExp so that
codegen knows it's allowed to put the array on the stack if it wants to.

Comments appreciated.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------