Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : ghc-7.6
http://hackage.haskell.org/trac/ghc/changeset/b637a24dbb471d99887e5544037a2abe10af26ee >--------------------------------------------------------------- commit b637a24dbb471d99887e5544037a2abe10af26ee Author: Simon Peyton Jones <simo...@microsoft.com> Date: Mon Dec 3 16:57:30 2012 +0000 Fix Trac #7453 on the 7.6 branch This patch fixes a quite egregious bug. runTcS was intialising the 'untouchables' to NoUntouchables, which is quite wrong for the invocation in TcSimplify.simplifyInfer. Result: missed skolem-escape check and seg-fault city. All this is done differently, and better, in HEAD, so this patch is needed only on the branch. >--------------------------------------------------------------- compiler/typecheck/TcSMonad.lhs | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/compiler/typecheck/TcSMonad.lhs b/compiler/typecheck/TcSMonad.lhs index eaaa8f6..8adb1d5 100644 --- a/compiler/typecheck/TcSMonad.lhs +++ b/compiler/typecheck/TcSMonad.lhs @@ -935,6 +935,15 @@ runTcSWithEvBinds ev_binds_var tcs ; inert_var <- TcM.newTcRef is ; wl_var <- TcM.newTcRef wl + -- The "low end" of the untouchable range should come from the + -- ambient tcl_untch; the high end is the highest allocated to + -- date. 'untouch' used (in 7.6.1, entirely wrongly) to be + -- set to NoUntouchables, causing #7453. + -- All this is done much better in 7.8. + ; tc_lenv <- TcM.getLclEnv + ; tcm_high <- TcM.readTcRef (tcl_meta tc_lenv) + ; let untouch = TouchableRange tcm_low tcm_high + tcm_low = tcl_untch tc_lenv ; let env = TcSEnv { tcs_ev_binds = ev_binds_var , tcs_ty_binds = ty_binds_var , tcs_untch = (untouch, emptyVarSet) -- No Tcs untouchables yet @@ -960,7 +969,6 @@ runTcSWithEvBinds ev_binds_var tcs ; return res } where do_unification (tv,ty) = TcM.writeMetaTyVar tv ty - untouch = NoUntouchables is = emptyInert wl = emptyWorkList _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
