[GHC] #8310: Can we change the semantics of `Trustworthy`?

[GHC]

#8310: Can we change the semantics of `Trustworthy`?
-------------------------------------+------------------------------------
        Reporter:  ekmett            |            Owner:  dterei
            Type:  feature request   |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
-------------------------------------+------------------------------------

Comment (by ekmett):

 My understanding was that if I import a module that is Trustworthy, my
 module could still infer as Safe-Inferred. Perhaps that was a naïve
 interpretation. I'll need to go back through and re-read the
 specification, and understand the safe import machinery better.

 Right now my main problem is that no matter what I do, I've just not
 proven smart enough to make the most specific annotation that works for
 all of my dependencies without unnecessarily enlarging the trusted code
 base.

 One possible middle ground that doesn't muddle those semantics is that we
 could issue a warning when you needlessly mark a module as Trustworthy,
 when it would otherwise infer as Safe-Inferred. Then I'd at least get some
 kind of feedback during the development process and from my end-users, and
 cleaning up warnings would catalyze users into writing patches.

 This would still result in me having to maintain some painfully
 complicated logic to get the right safety properties, but it would at
 least tell me pointwise when I was in a situation where I'd gotten it
 wrong.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8310#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler