GHC.Runtime: avoid DynFlags (#17957)

* add `getPlatform :: TcM Platform` helper
* remove unused `DynFlags` parameter from `emptyPLS`

3 files changed, 18 insertions, 11 deletions

diff --git a/compiler/GHC/Runtime/Heap/Inspect.hs b/compiler/GHC/Runtime/Heap/Inspect.hs
index 3802baf4df..0c856aa7a5 100644
--- a/compiler/GHC/Runtime/Heap/Inspect.hs
+++ b/compiler/GHC/Runtime/Heap/Inspect.hs
@@ -865,7 +865,7 @@ extractSubTerms recurse clos = liftM thdOf3 . go 0 0
           -- This is a bit involved since we allow packing multiple fields
           -- within a single word. See also
           -- GHC.StgToCmm.Layout.mkVirtHeapOffsetsWithPadding
-          platform <- targetPlatform <$> getDynFlags
+          platform <- getPlatform
           let word_size = platformWordSizeInBytes platform
               endian = platformByteOrder platform
               size_b = primRepSizeB platform rep
diff --git a/compiler/GHC/Runtime/Linker.hs b/compiler/GHC/Runtime/Linker.hs
index 5da9a916af..c103feb3fc 100644
--- a/compiler/GHC/Runtime/Linker.hs
+++ b/compiler/GHC/Runtime/Linker.hs
@@ -127,15 +127,15 @@ modifyMbPLS_
   :: DynLinker -> (Maybe PersistentLinkerState -> IO (Maybe PersistentLinkerState)) -> IO ()
 modifyMbPLS_ dl f = modifyMVar_ (dl_mpls dl) f
 
-emptyPLS :: DynFlags -> PersistentLinkerState
-emptyPLS _ = PersistentLinkerState {
-                        closure_env = emptyNameEnv,
-                        itbl_env    = emptyNameEnv,
-                        pkgs_loaded = init_pkgs,
-                        bcos_loaded = [],
-                        objs_loaded = [],
-                        temp_sos = [] }
-
+emptyPLS :: PersistentLinkerState
+emptyPLS = PersistentLinkerState
+   { closure_env = emptyNameEnv
+   , itbl_env    = emptyNameEnv
+   , pkgs_loaded = init_pkgs
+   , bcos_loaded = []
+   , objs_loaded = []
+   , temp_sos = []
+   }
   -- Packages that don't need loading, because the compiler
   -- shares them with the interpreted program.
   --
@@ -280,7 +280,7 @@ reallyInitDynLinker :: HscEnv -> IO PersistentLinkerState
 reallyInitDynLinker hsc_env = do
   -- Initialise the linker state
   let dflags = hsc_dflags hsc_env
-      pls0 = emptyPLS dflags
+      pls0 = emptyPLS
 
   -- (a) initialise the C dynamic linker
   initObjLinker hsc_env
diff --git a/compiler/GHC/Tc/Types.hs b/compiler/GHC/Tc/Types.hs
index e5f5fdbf50..8c4086a2ca 100644
--- a/compiler/GHC/Tc/Types.hs
+++ b/compiler/GHC/Tc/Types.hs
@@ -70,6 +70,7 @@ module GHC.Tc.Types(
         TcId, TcIdSet,
         NameShape(..),
         removeBindingShadowing,
+        getPlatform,
 
         -- Constraint solver plugins
         TcPlugin(..), TcPluginResult(..), TcPluginSolver,
@@ -84,6 +85,7 @@ module GHC.Tc.Types(
 #include "HsVersions.h"
 
 import GhcPrelude
+import GHC.Platform
 
 import GHC.Hs
 import GHC.Driver.Types
@@ -902,6 +904,11 @@ removeBindingShadowing bindings = reverse $ fst $ foldl
         else (binding:bindingAcc, extendOccSet seenNames (occName binding)))
     ([], emptyOccSet) bindings
 
+
+-- | Get target platform
+getPlatform :: TcM Platform
+getPlatform = targetPlatform <$> getDynFlags
+
 ---------------------------
 -- Template Haskell stages and levels
 ---------------------------