[commit: ghc] master: A collection of type-inference refactorings. (3f5673f)

[Erik de Castro Lopo]

Simon Peyton Jones via ghc-devs wrote:

> You'll have seen a brief flurry of commits from me, of which this is the
> biggest. I've managed to spend some time on the typechecker recently, and
> this is the result.
> 
> I'm pleased with the results (simpler code, more predictable behaviour),
> but although I worked through the changes with Richard, I may have
> introduced new bugs, so keep an eye out.

Simon,

I suspect these commits may be responsible for 11 test failures:

  Unexpected results from:
  TEST="T9857 T12007 T9732 T9783 T9867 unboxed-wrapper-naked match-unboxed num T12698 T4439 unboxed-wrapper"

  SUMMARY for test run started at Sun Oct 23 16:56:26 2016 AEDT
   0:00:02 spent to go through
      11 total tests, which gave rise to
      47 test cases, of which
      36 were skipped

       0 had missing libraries
       0 expected passes
       0 expected failures

       0 caused framework failures
       0 unexpected passes
      11 unexpected failures
       0 unexpected stat failures

  Unexpected failures:
   deSugar/should_compile/T4439.run              T4439 [exit code non-0] (normal)
   ghci/scripts/T12007.run                       T12007 [bad stderr] (ghci)
   patsyn/should_compile/num.run                 num [exit code non-0] (normal)
   patsyn/should_compile/T9732.run               T9732 [exit code non-0] (normal)
   patsyn/should_compile/T9857.run               T9857 [exit code non-0] (normal)
   patsyn/should_compile/T9867.run               T9867 [exit code non-0] (normal)
   patsyn/should_compile/T12698.run              T12698 [exit code non-0] (normal)
   patsyn/should_fail/unboxed-wrapper-naked.run  unboxed-wrapper-naked [stderr mismatch] (normal)
   patsyn/should_run/T9783.run                   T9783 [exit code non-0] (normal)
   patsyn/should_run/match-unboxed.run           match-unboxed [exit code non-0] (normal)
   patsyn/should_run/unboxed-wrapper.run         unboxed-wrapper [exit code non-0] (normal)

They all fail with exactly the same callstack:

  ghc-stage2: panic! (the 'impossible' happened)
    (GHC version 8.1.20161022 for x86_64-unknown-linux):
	  ASSERT failed!
    Infer{apr,2 True} :: TYPE t_apq[tau:2]
    a_a1pr[tau:2]
    Call stack:
      CallStack (from HasCallStack):
        prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1076:58 in ghc:Outputable
        callStackDoc, called at compiler/utils/Outputable.hs:1125:22 in ghc:Outputable
        assertPprPanic, called at compiler/typecheck/TcUnify.hs:547:56 in ghc:TcUnify
  Call stack:
      CallStack (from HasCallStack):
        prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1076:58 in ghc:Outputable
        callStackDoc, called at compiler/utils/Outputable.hs:1080:37 in ghc:Outputable
        pprPanic, called at compiler/utils/Outputable.hs:1123:5 in ghc:Outputable
        assertPprPanic, called at compiler/typecheck/TcUnify.hs:547:56 in ghc:TcUnify


Cheers,
Erik
-- 
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/