"Probable" because this was found by code inspection after enabling warning 27. I assume
this could lead to an actual bug in the type-checker, but I have not tried to trigger it.
Fix confirmed by @garrigue.
This commit adds errors for bad uses of @untagged and
@unboxed attributes in external declarations.
There are three possible new errors:
- One when the external does not contain a native version of
the primitive,
- One when the attribute occurs deeply into the type,
- One when the attribute is applied to the whole function type.
the following type error
"Type a is not compatible with type 'a"
should contain the constraint on 'a.
"Type a is not compatible with type 'a = < .. >"
"Type a is not compatible with type 'a = [> `b]"
This week we merged several changes from Thomas Refis, to allow the
use of exception patterns under or-patterns, to write code such as
match foo x with
| None | exception Not_found -> ...
| Some -> ...
Unfortunately, I failed to properly assess the impact of this change,
and in particular to make sure that Luc Maranget had properly reviewed
this code -- any change to the pattern-matching machinery should be
reviewed by Luc.
The problem that I had not foreseen and that he would have immediately
realized is that, while adapting the pattern-matching *compiler* is
relatively easy (Thomas inserted a transformation at the right place
to separate exception patterns from the others and handle them
separately, using the staticraise construct used by the
pattern-matching compiler to avoid duplicating the
right-hand-side branch), adapting the pattern-matching warnings
machinery is both more subtle and easier to overlook (it may fail
silently and nobody notices, unlike wrong code production). This part
of the compiler is subtle and best understood by Luc, but he does not
have the time to do a proper review of those changes in the timeframe
for the 4.03 feature freeze (mid-December).
I believe the right move in this case, implemented in the present
commit, is to revert the change from trunk (this is not a feature that
we must *imperatively* have in 4.03), do a proper job of understanding
the changes, and integrate the change when we are confident it is
ready. I hope to do this in 2016, together with Luc Maranget and
Thomas Refis -- hopefully this would allow Thomas and I to be more
confident when changing the pattern-matching machinery in the future.
Revert "Merge pull request #343 from trefis/pr7083"
This reverts commit 22681b8d2a, reversing
changes made to a24e4edf0a.
Revert "Merge pull request #341 from trefis/or-exception"
This reverts commit f8f68bd329, reversing
changes made to 1534fe8082.
Revert "Merge pull request #305 from trefis/or-exception"
This reverts commit cfeda89396, reversing
changes made to 77cf36cf82.
alainfrisch
Jacques Garrigue
Damien Doligez
Will Crichton
Nicolas Ojeda Bar
Jeremie Dimino
Damien Doligez
Thomas Refis
Jérémie Dimino
Marc Lasson
Drup
Pierre Chambart
Mark Shinwell
Leo White
Hugo Heuzard
maranget
Gabriel Scherer
Luc Maranget