Start using `-W` instead of `-f(no-)warn` in some places

This replaces some occurences of `-f(no-)warn` with the new `-W`-aliases
introduced via 2206fa8cdb120932 / #11218, in cases which are guaranteed
to be invoked with recent enough GHC (i.e. the stage1+ GHC).

After this commit, mostly the compiler and the testsuite remain using
`-f(wo-)warn...` because the compiler needs to be bootstrappable with
older GHCs, while for the testsuite it's convenient to be able to quickly
compare the behavior to older GHCs (which may not support the new flags yet).

The compiler-part can be updated to use the new flags once GHC 8.3 development
starts.

Reviewed By: quchen

Differential Revision: https://phabricator.haskell.org/D1637

19 files changed, 26 insertions, 26 deletions

diff --git a/libraries/base/Control/Arrow.hs b/libraries/base/Control/Arrow.hs
index 8a4bc2d22f..3417f30cc1 100644
--- a/libraries/base/Control/Arrow.hs
+++ b/libraries/base/Control/Arrow.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE NoImplicitPrelude #-}
-{-# OPTIONS_GHC -fno-warn-inline-rule-shadowing #-}
+{-# OPTIONS_GHC -Wno-inline-rule-shadowing #-}
     -- The RULES for the methods of class Arrow may never fire
     -- e.g. compose/arr;  see Trac #10528
 
diff --git a/libraries/base/Control/Category.hs b/libraries/base/Control/Category.hs
index 8616a17cdd..b638189b60 100644
--- a/libraries/base/Control/Category.hs
+++ b/libraries/base/Control/Category.hs
@@ -2,7 +2,7 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE NoImplicitPrelude #-}
 {-# LANGUAGE PolyKinds #-}
-{-# OPTIONS_GHC -fno-warn-inline-rule-shadowing #-}
+{-# OPTIONS_GHC -Wno-inline-rule-shadowing #-}
     -- The RULES for the methods of class Category may never fire
     -- e.g. identity/left, identity/right, association;  see Trac #10528
 
diff --git a/libraries/base/Control/Concurrent.hs b/libraries/base/Control/Concurrent.hs
index 1786c3ded3..babe8d9a76 100644
--- a/libraries/base/Control/Concurrent.hs
+++ b/libraries/base/Control/Concurrent.hs
@@ -5,7 +5,7 @@
            , ScopedTypeVariables
            , RankNTypes
   #-}
-{-# OPTIONS_GHC -fno-warn-deprecations #-}
+{-# OPTIONS_GHC -Wno-deprecations #-}
 -- kludge for the Control.Concurrent.QSem, Control.Concurrent.QSemN
 -- and Control.Concurrent.SampleVar imports.
 
diff --git a/libraries/base/Foreign/C/Types.hs b/libraries/base/Foreign/C/Types.hs
index cc0eb1b729..fef8e4a3b6 100644
--- a/libraries/base/Foreign/C/Types.hs
+++ b/libraries/base/Foreign/C/Types.hs
@@ -1,8 +1,8 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP, NoImplicitPrelude, MagicHash, GeneralizedNewtypeDeriving,
              StandaloneDeriving #-}
-{-# OPTIONS_GHC -fno-warn-unused-binds #-}
--- XXX -fno-warn-unused-binds stops us warning about unused constructors,
+{-# OPTIONS_GHC -Wno-unused-binds #-}
+-- XXX -Wno-unused-binds stops us warning about unused constructors,
 -- but really we should just remove them if we don't want them
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Base.hs b/libraries/base/GHC/Base.hs
index 90eaaf0a1e..89ec703163 100644
--- a/libraries/base/GHC/Base.hs
+++ b/libraries/base/GHC/Base.hs
@@ -84,9 +84,9 @@ Other Prelude modules are much easier with fewer complex dependencies.
            , ExistentialQuantification
            , RankNTypes
   #-}
--- -fno-warn-orphans is needed for things like:
+-- -Wno-orphans is needed for things like:
 -- Orphan rule: "x# -# x#" ALWAYS forall x# :: Int# -# x# x# = 0
-{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Conc.hs b/libraries/base/GHC/Conc.hs
index 68182a11e4..38fac431b0 100644
--- a/libraries/base/GHC/Conc.hs
+++ b/libraries/base/GHC/Conc.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Unsafe #-}
 {-# LANGUAGE CPP, NoImplicitPrelude #-}
-{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Conc/IO.hs b/libraries/base/GHC/Conc/IO.hs
index 3a57c93369..b2c96b9fdb 100644
--- a/libraries/base/GHC/Conc/IO.hs
+++ b/libraries/base/GHC/Conc/IO.hs
@@ -4,7 +4,7 @@
            , MagicHash
            , UnboxedTuples
   #-}
-{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Conc/Sync.hs b/libraries/base/GHC/Conc/Sync.hs
index 83934fe05a..5e277332d0 100644
--- a/libraries/base/GHC/Conc/Sync.hs
+++ b/libraries/base/GHC/Conc/Sync.hs
@@ -8,7 +8,7 @@
            , StandaloneDeriving
            , RankNTypes
   #-}
-{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Conc/Windows.hs b/libraries/base/GHC/Conc/Windows.hs
index 16112cdd7c..8913a65907 100644
--- a/libraries/base/GHC/Conc/Windows.hs
+++ b/libraries/base/GHC/Conc/Windows.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP, NoImplicitPrelude, MagicHash, UnboxedTuples #-}
-{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Event/IntTable.hs b/libraries/base/GHC/Event/IntTable.hs
index 8d0f1797c2..ea487d5391 100644
--- a/libraries/base/GHC/Event/IntTable.hs
+++ b/libraries/base/GHC/Event/IntTable.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE BangPatterns, NoImplicitPrelude, RecordWildCards #-}
-{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
+{-# OPTIONS_GHC -Wno-name-shadowing #-}
 
 module GHC.Event.IntTable
     (
diff --git a/libraries/base/GHC/Float.hs b/libraries/base/GHC/Float.hs
index 74d7cb8f01..e6180afcf6 100644
--- a/libraries/base/GHC/Float.hs
+++ b/libraries/base/GHC/Float.hs
@@ -6,7 +6,7 @@
   #-}
 -- We believe we could deorphan this module, by moving lots of things
 -- around, but we haven't got there yet:
-{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/IO/Encoding/CodePage/API.hs b/libraries/base/GHC/IO/Encoding/CodePage/API.hs
index 7fd22cb012..103eb87a0d 100644
--- a/libraries/base/GHC/IO/Encoding/CodePage/API.hs
+++ b/libraries/base/GHC/IO/Encoding/CodePage/API.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP, NoImplicitPrelude, NondecreasingIndentation,
              RecordWildCards, ScopedTypeVariables #-}
-{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
+{-# OPTIONS_GHC -Wno-name-shadowing #-}
 
 module GHC.IO.Encoding.CodePage.API (
     mkCodePageEncoding
diff --git a/libraries/base/GHC/IO/FD.hs b/libraries/base/GHC/IO/FD.hs
index edce50003d..eb7b80bb44 100644
--- a/libraries/base/GHC/IO/FD.hs
+++ b/libraries/base/GHC/IO/FD.hs
@@ -3,7 +3,7 @@
            , NoImplicitPrelude
            , BangPatterns
   #-}
-{-# OPTIONS_GHC -fno-warn-identities #-}
+{-# OPTIONS_GHC -Wno-identities #-}
 -- Whether there are identities depends on the platform
 {-# OPTIONS_HADDOCK hide #-}
 
diff --git a/libraries/base/GHC/IO/Handle.hs b/libraries/base/GHC/IO/Handle.hs
index ac37ad45f9..750dbf7a4d 100644
--- a/libraries/base/GHC/IO/Handle.hs
+++ b/libraries/base/GHC/IO/Handle.hs
@@ -4,7 +4,7 @@
            , RecordWildCards
            , NondecreasingIndentation
   #-}
-{-# OPTIONS_GHC -fno-warn-unused-matches #-}
+{-# OPTIONS_GHC -Wno-unused-matches #-}
 
 -----------------------------------------------------------------------------
 -- |
diff --git a/libraries/base/GHC/IO/Handle/Internals.hs b/libraries/base/GHC/IO/Handle/Internals.hs
index 37251abd06..581eb9bbfa 100644
--- a/libraries/base/GHC/IO/Handle/Internals.hs
+++ b/libraries/base/GHC/IO/Handle/Internals.hs
@@ -5,8 +5,8 @@
            , NondecreasingIndentation
            , RankNTypes
   #-}
-{-# OPTIONS_GHC -fno-warn-unused-matches #-}
-{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
+{-# OPTIONS_GHC -Wno-unused-matches #-}
+{-# OPTIONS_GHC -Wno-name-shadowing #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/IO/Handle/Text.hs b/libraries/base/GHC/IO/Handle/Text.hs
index 88ec3c4e67..c31ab70a4a 100644
--- a/libraries/base/GHC/IO/Handle/Text.hs
+++ b/libraries/base/GHC/IO/Handle/Text.hs
@@ -6,8 +6,8 @@
            , NondecreasingIndentation
            , MagicHash
   #-}
-{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
-{-# OPTIONS_GHC -fno-warn-unused-matches #-}
+{-# OPTIONS_GHC -Wno-name-shadowing #-}
+{-# OPTIONS_GHC -Wno-unused-matches #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/GHC/Real.hs b/libraries/base/GHC/Real.hs
index 71de0d27d7..31381d6bd9 100644
--- a/libraries/base/GHC/Real.hs
+++ b/libraries/base/GHC/Real.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP, NoImplicitPrelude, MagicHash, UnboxedTuples, BangPatterns #-}
-{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
diff --git a/libraries/base/Text/Show/Functions.hs b/libraries/base/Text/Show/Functions.hs
index 690b203ea3..5230a4b4ca 100644
--- a/libraries/base/Text/Show/Functions.hs
+++ b/libraries/base/Text/Show/Functions.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Safe #-}
 -- This module deliberately declares orphan instances:
-{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
 
 -----------------------------------------------------------------------------
 -- |
diff --git a/libraries/ghc-prim/GHC/Classes.hs b/libraries/ghc-prim/GHC/Classes.hs
index 0e74bef07c..19192fb725 100644
--- a/libraries/ghc-prim/GHC/Classes.hs
+++ b/libraries/ghc-prim/GHC/Classes.hs
@@ -7,11 +7,11 @@
 {-# LANGUAGE UndecidableSuperClasses #-}
   -- Because of the type-variable superclasses for tuples
 
-{-# OPTIONS_GHC -fno-warn-unused-imports #-}
--- -fno-warn-unused-imports needed for the GHC.Tuple import below. Sigh.
+{-# OPTIONS_GHC -Wno-unused-imports #-}
+-- -Wno-unused-imports needed for the GHC.Tuple import below. Sigh.
 
-{-# OPTIONS_GHC -fno-warn-unused-top-binds #-}
--- -fno-warn-unused-top-binds is there (I hope) to stop Haddock complaining
+{-# OPTIONS_GHC -Wno-unused-top-binds #-}
+-- -Wno-unused-top-binds is there (I hope) to stop Haddock complaining
 -- about the constraint tuples being defined but not used
 
 {-# OPTIONS_HADDOCK hide #-}