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authorSimon Peyton Jones <simonpj@microsoft.com>2018-08-20 09:48:41 +0100
committerSimon Peyton Jones <simonpj@microsoft.com>2018-08-20 14:21:38 +0100
commit2dcebe69f07f9b4328bc3dc2131ccf2953ffa21b (patch)
tree2106ada6f22bd198dc1891f1283740d26bf4047d /compiler/llvmGen/LlvmCodeGen/CodeGen.hs
parenta08b285f74cd49196feb0f819d70ad0508689da3 (diff)
downloadhaskell-wip/T13064.tar.gz
Fix unused-import warningswip/T13064
This patch fixes a fairly long-standing bug (dating back to 2015) in RdrName.bestImport, namely commit 9376249b6b78610db055a10d05f6592d6bbbea2f Author: Simon Peyton Jones <simonpj@microsoft.com> Date: Wed Oct 28 17:16:55 2015 +0000 Fix unused-import stuff in a better way In that patch got the sense of the comparison back to front, and thereby failed to implement the unused-import rules described in Note [Choosing the best import declaration] in RdrName This led to Trac #13064 and #15393 Fixing this bug revealed a bunch of unused imports in libraries; the ones in the GHC repo are part of this commit. The two important changes are * Fix the bug in bestImport * Modified the rules by adding (a) in Note [Choosing the best import declaration] in RdrName Reason: the previosu rules made Trac #5211 go bad again. And the new rule (a) makes sense to me. In unravalling this I also ended up doing a few other things * Refactor RnNames.ImportDeclUsage to use a [GlobalRdrElt] for the things that are used, rather than [AvailInfo]. This is simpler and more direct. * Rename greParentName to greParent_maybe, to follow GHC naming conventions * Delete dead code RdrName.greUsedRdrName * Slightly change the spec of the unused function HsImpExpr.ieLWrappedName, and use it in RnNames.findImportUsage
Diffstat (limited to 'compiler/llvmGen/LlvmCodeGen/CodeGen.hs')
-rw-r--r--compiler/llvmGen/LlvmCodeGen/CodeGen.hs1
1 files changed, 0 insertions, 1 deletions
diff --git a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
index 51de1f6850..7c6de7fe43 100644
--- a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
+++ b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
@@ -38,7 +38,6 @@ import Util
import Control.Monad.Trans.Class
import Control.Monad.Trans.Writer
-import Data.Semigroup ( Semigroup )
import qualified Data.Semigroup as Semigroup
import Data.List ( nub )
import Data.Maybe ( catMaybes )