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| author | Alp Mestanogullari <alp@well-typed.com> | 2018-11-12 15:38:46 +0100 |
|---|---|---|
| committer | Alp Mestanogullari <alp@well-typed.com> | 2018-11-12 17:50:06 +0100 |
| commit | 86ee74dc999db6030874ddaf5d10adec23108c02 (patch) | |
| tree | e9a24641ae01c692ffc0661e15594cb2185b3127 /compiler/main/Packages.hs | |
| parent | d30352add1da67dd0346613853cd423c7becbaeb (diff) | |
| download | haskell-86ee74dc999db6030874ddaf5d10adec23108c02.tar.gz | |
compareByPreference: handle the integer-gmp vs -simple case
Currently, it assumes the package names are identical and this
breaks in the case where integer-gmp is in one package db and
integer-simple in another. This became a problem with
the commit: fc2ff6dd7496a33bf68165b28f37f40b7d647418.
Instead of following the precedence information, leading to
the right choice, the current code would compare the
integer-gmp and integer-simple versions and pick integer-gmp
because it happened to have a greater version, despite having
a lower precedence. See
https://github.com/snowleopard/hadrian/issues/702 for
a comprehensive report about the problem.
This effectively un-breaks integer-simple builds with hadrian.
Test Plan: hadrian/build.sh --integer-simple
Reviewers: snowleopard, bgamari
Reviewed By: bgamari
Subscribers: snowleopard, rwbarton, carter
Differential Revision: https://phabricator.haskell.org/D5266
Diffstat (limited to 'compiler/main/Packages.hs')
| -rw-r--r-- | compiler/main/Packages.hs | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/compiler/main/Packages.hs b/compiler/main/Packages.hs index fadcd31f1e..78d5961ee2 100644 --- a/compiler/main/Packages.hs +++ b/compiler/main/Packages.hs @@ -891,15 +891,28 @@ sortByPreference prec_map = sortBy (flip (compareByPreference prec_map)) -- -- Pursuant to #12518, we could change this policy to, for example, remove -- the version preference, meaning that we would always prefer the packages --- in alter package database. +-- in later package database. -- +-- Instead, we use that preference based policy only when one of the packages +-- is integer-gmp and the other is integer-simple. +-- This currently only happens when we're looking up which concrete +-- package to use in place of @integer-wired-in@ and that two different +-- package databases supply a different integer library. For more about +-- the fake @integer-wired-in@ package, see Note [The integer library] +-- in the @PrelNames@ module. compareByPreference :: PackagePrecedenceIndex -> PackageConfig -> PackageConfig -> Ordering -compareByPreference prec_map pkg pkg' = - case comparing packageVersion pkg pkg' of +compareByPreference prec_map pkg pkg' + | Just prec <- Map.lookup (unitId pkg) prec_map + , Just prec' <- Map.lookup (unitId pkg') prec_map + , differentIntegerPkgs pkg pkg' + = compare prec prec' + + | otherwise + = case comparing packageVersion pkg pkg' of GT -> GT EQ | Just prec <- Map.lookup (unitId pkg) prec_map , Just prec' <- Map.lookup (unitId pkg') prec_map @@ -910,6 +923,12 @@ compareByPreference prec_map pkg pkg' = -> EQ LT -> LT + where isIntegerPkg p = packageNameString p `elem` + ["integer-simple", "integer-gmp"] + differentIntegerPkgs p p' = + isIntegerPkg p && isIntegerPkg p' && + (packageName p /= packageName p') + comparing :: Ord a => (t -> a) -> t -> t -> Ordering comparing f a b = f a `compare` f b |