[GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
6 messages Options
Reply | Threaded
Open this post in threaded view
|

[GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
           Reporter:  rwbarton       |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 By default (without `NegativeLiterals`) a negated literal `-1` is
 desugared as `negate (fromInteger 1)`. Hence the existing out-of-range
 literal warning doesn't trigger for `-1 :: Word`. But we could also
 recognize the pattern `negate (fromInteger lit)`, and give a warning when
 `-lit` is out-of-range (for `Word`, this is whenever `lit` is positive).

 Actually this could apply to signed integer types too: if we recognized
 `negate (fromInteger lit)` in preference to `fromInteger lit`, we could
 correctly not warn about `-128 :: Int8`, even when `NegativeLiterals` is
 not enabled.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets
Reply | Threaded
Open this post in threaded view
|

Re: [GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by rwbarton):

 * keywords:   => newcomer


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets
Reply | Threaded
Open this post in threaded view
|

Re: [GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
In reply to this post by GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  ruperthorlick
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  deSugar/should_compile/T13257
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3281
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by ruperthorlick):

 * owner:  (none) => ruperthorlick
 * testcase:   => deSugar/should_compile/T13257
 * differential:   => Phab:D3281


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler

_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets
Reply | Threaded
Open this post in threaded view
|

Re: [GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
In reply to this post by GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  ruperthorlick
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  deSugar/should_compile/T13257
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3281
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by ruperthorlick):

 * status:  new => patch


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler

_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets
Reply | Threaded
Open this post in threaded view
|

Re: [GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
In reply to this post by GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  ruperthorlick
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  deSugar/should_compile/T13257
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3281
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"3fdabe9873e311571f614d455d1b16bc3f4fdc0f/ghc"
 3fdabe98/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="3fdabe9873e311571f614d455d1b16bc3f4fdc0f"
 Changed OverLit warnings to work with negative literals (#13257)

 Test Plan: Validate, check generated warnings

 Reviewers: austin, bgamari, dfeuer

 Reviewed By: bgamari, dfeuer

 Subscribers: dfeuer, thomie

 Differential Revision: https://phabricator.haskell.org/D3281
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler

_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets
Reply | Threaded
Open this post in threaded view
|

Re: [GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals

GHC - devs mailing list
In reply to this post by GHC - devs mailing list
#13257: out-of-range warnings for negative literals, without -XNegativeLiterals
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  ruperthorlick
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  deSugar/should_compile/T13257
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3281
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by monoidal):

 Is it correct not to warn about `-128 :: Int8` when `-XNegativeLiterals`
 is off? After all, without -XNegativeLiterals this means creating the
 overflowed integer `128 :: Int8` and only then negating it.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler

_______________________________________________
ghc-tickets mailing list
[hidden email]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets