[M3devel] INTEGER vs. LONGINT vs. Target.Int in m3cg?

[Jay K]

Huh? You mean hack, cross once, unhack?
I want to cross build as a regular occurence. The entire system.
I already do actually. But currently only enough to get cm3.
The problems occur if you try to build the entire system.
  Ok, right, I left one of the hacks in actually.
  Like TEXTs have a 2GB size limit or such.


"Regular" cross builds are normal in other environments these days.


 - Jay

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> Subject: Re: [M3devel] INTEGER vs. LONGINT vs. Target.Int in m3cg?
> From: hosking at cs.purdue.edu
> Date: Thu, 30 Sep 2010 09:42:59 -0400
> CC: m3devel at elegosoft.com
> To: jay.krell at cornell.edu
>
> Whenever you cross build you should do a subsequent native bootstrap to eliminate those.
>
> On 30 Sep 2010, at 07:14, Jay K wrote:
>
> >
> > So..we can't fully cross build a 64bit target from a 32bit host because some code
> > wants to declare arrays that fill memory, like so that indexing them never fails
> > an overflow check:
> >
> >
> > TYPE T = ARRAY [0..LAST(INTEGER)] OF CHAR; for example
> >
> >
> > I'm faced with a few choices:
> > - do nothing
> > - have the front end pin the sizes to its maximum
> > Leading to such code to fail if it actually operates on data larger than 2GB
> > - use Target.Int a lot more, and in parse.c TARGET_INTEGER more, INTEGER less
> > - use LONGINT a lot more (zero vs. a lot), and in parse.c "long long" in place of "long",
> > (roughly: "long" suffices instead on most 64bit systems)
> > - possibly a hybrid of previous two: Target.Int in m3middle/m3front, long long in parse.c
> >
> >
> > Extremely similarly btw:
> >
> >
> > TYPE T1 = ARRAY [0..16_LAST(INTEGER) DIV 4] OF CHAR; for example
> > TYPE T2 = RECORD a,b,c:T1; END;
> >
> >
> > which is just to say, it isn't just about total array sizes, but also field offsets.
> >
> >
> > (I'll add the obvious: this is the sort of thing where C++ operator overloading really shines...)
> >
> >
> >
> > I'm dreading that the sort of conservative/portable answer -- Target.Int and TARGET_INTEGER, will touch *a lot* of code.
> > e.g. m3front/src/types/Type.i3/Info, and then all its users.
> >
> > Should these types use a different and unsafe form?
> > Do we have a convenient unsafe form?
> >
> > - Jay
> >
>