Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!peer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED!nerds-end From: wclodius@earthlink.net (William Clodius) Newsgroups: comp.compilers Subject: Re: Safe Pointers at the Intermediate Language or Hardware Level Date: Mon, 10 Feb 2014 23:03:36 -0700 Organization: Compilers Central Lines: 32 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <14-02-011@comp.compilers> References: <14-02-007@comp.compilers> NNTP-Posting-Host: news.iecc.com X-Trace: miucha.iecc.com 1392101553 74091 64.57.183.58 (11 Feb 2014 06:52:33 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Tue, 11 Feb 2014 06:52:33 +0000 (UTC) Keywords: architecture, debug Posted-Date: 11 Feb 2014 01:52:32 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com X-Received-Bytes: 2138 X-Received-Body-CRC: 3175214468 Xref: csiph.com comp.compilers:1090 wrote: > Its been a long time since Java & .Net introduced safe address > types to the computing world. > > My question is have we settled on what could be a proper representation > for safe pointers ? > > Some Mainframes like the 390 have historically supported safe pointers, > I remember. > > Sincerely, > Seima Rao. > [I looked at my S/390 Principles of Operation, and I see a bunch of stuff > for tracing, but nothing that looks like safe pointers. I'd think it was > hardware dependent, e.g., if a machine has a fairly clean and efficient > trap for an unmapped zero address, you'd use that, but if it doesn't, you'd > do something else. -John] To me it sounds like they are interested either in capabaility architectures or something similar to dope vectors http://en.wikipedia.org/wiki/Dope_vector for something like Algol 60/68, APL, Matlab, or Fortran 90+. Dope vectors can in principle be used for scalars as well as arrays, as a software substitute for a capability architecture, but most users would dislike the overhead.