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From: "Christoph Höger" <christoph.hoeger@celeraone.com>
To: OCaml Mailing List <caml-list@inria.fr>
Subject: [Caml-list] How is the frametable handled when throwing exceptions?
Date: Sat, 11 Feb 2017 15:02:22 +0100	[thread overview]
Message-ID: <CAOazmvtjUQo9ksbq=ox8EqbC25vE6oJbD08LzEPd_V1K=xfsBw@mail.gmail.com> (raw)

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Dear all,

while studying camls native code generation and garbage collection
strategy, I came upon Connor Benner's bachelor thesis from 2012, where he
implemented a llvm backend for ocamlopt. One intriguing remark mentioned
OCamls exception mechanism as basically consisting a pointer to the stack
frame of the last exception handler in a special register (r14, when I
recall correctly). Throwing an exception that becomes a mov/pop/ret
operation. This however, seems to interfere with garbage collection: From
the C-API, it seems that all local roots are stored in the frametable via
some special macros (e.g. CAMLParam, CAMLlocal).

When control just returns from a stack frame, how are the entries removed
from the frametable?

I would be glad, if someone could answer this or point me to the relevant
documentation (if any exists).

thanks,

Christoph

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             reply	other threads:[~2017-02-11 14:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-11 14:02 Christoph Höger [this message]
2017-02-11 14:10 ` Nicolás Ojeda Bär
2017-02-12 13:25   ` Christoph Höger
2017-02-12 14:55     ` Nicolás Ojeda Bär
2017-02-13 15:13 ` Stephen Dolan

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