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author | George Karachalias <george.karachalias@gmail.com> | 2015-12-27 23:05:02 +0100 |
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committer | Ben Gamari <ben@smart-cactus.org> | 2015-12-27 23:06:32 +0100 |
commit | bec5350da09fde51231004b1b7d33641ac51800e (patch) | |
tree | 2cdd4f637353f2379e381c2385c9975ff7b2642c /libraries/base/Foreign | |
parent | 07b3be76a14a061a43846ef41f1dd7819603be4e (diff) | |
download | haskell-bec5350da09fde51231004b1b7d33641ac51800e.tar.gz |
Adding flags: -ffull-guard-reasoning and too-many-guards
Introduction of two new flags, for more precise control over the new
pattern match checker's behaviour when reasoning about guards. This is
supposed to address #11195 (and maybe more performance bugs related to
the NP-Hardness of coverage checking).
Expected behaviour:
* When `-ffull-guard-reasoning` is on, run the new pattern match
checker in its full power
* When `-ffull-guard-reasoning` is off (the default), for every
match, check a metric to see whether pattern match checking for it
has high probability of being non performant (at the the moment we
check whether the number of guards is over 20 but I would like to
use a more precise measure in the future). If the probability is
high:
- Oversimplify the guards (less expressive but more performant)
and run the checker, and
- Issue a warning about the simplification that happened.
A new flag `-Wtoo-many-guards/-Wno-too-many-guards` suppresses the
warning about the simplification (useful when combined with -Werror).
Test Plan: validate
Reviewers: goldfire, austin, hvr, bgamari
Reviewed By: bgamari
Subscribers: mpickering, thomie
Differential Revision: https://phabricator.haskell.org/D1676
GHC Trac Issues: #11195
Diffstat (limited to 'libraries/base/Foreign')
-rw-r--r-- | libraries/base/Foreign/C/Error.hs | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/libraries/base/Foreign/C/Error.hs b/libraries/base/Foreign/C/Error.hs index 761435183e..4607c37992 100644 --- a/libraries/base/Foreign/C/Error.hs +++ b/libraries/base/Foreign/C/Error.hs @@ -1,5 +1,6 @@ {-# LANGUAGE Trustworthy #-} {-# LANGUAGE CPP, NoImplicitPrelude #-} +{-# OPTIONS_GHC -ffull-guard-reasoning #-} ----------------------------------------------------------------------------- -- | |