Adjust flags for pprTracewip/T21569

We were using defaultSDocContext for pprTrace, which suppresses
lots of useful infomation. This small MR adds

   GHC.Utils.Outputable.traceSDocContext

and uses it for pprTrace and pprTraceUserWarning.

traceSDocContext is a global, and hence not influenced by flags,
but that seems unavoidable.  But I made the sdocPprDebug bit
controlled by unsafeHasPprDebug, since we have the latter for
exactly this purpose.

Fixes #21569

1 files changed, 15 insertions, 1 deletions

diff --git a/compiler/GHC/Utils/Outputable.hs b/compiler/GHC/Utils/Outputable.hs
index f424076e04..032c8502f8 100644
--- a/compiler/GHC/Utils/Outputable.hs
+++ b/compiler/GHC/Utils/Outputable.hs
@@ -90,7 +90,8 @@ module GHC.Utils.Outputable (
         QualifyName(..), queryQual,
         sdocOption,
         updSDocContext,
-        SDocContext (..), sdocWithContext, defaultSDocContext,
+        SDocContext (..), sdocWithContext,
+        defaultSDocContext, traceSDocContext,
         getPprStyle, withPprStyle, setStyleColoured,
         pprDeeper, pprDeeperList, pprSetDepth,
         codeStyle, userStyle, dumpStyle, asmStyle,
@@ -116,6 +117,7 @@ import qualified GHC.Utils.Ppr.Colour as Col
 import GHC.Utils.Ppr       ( Doc, Mode(..) )
 import GHC.Serialized
 import GHC.LanguageExtensions (Extension)
+import GHC.Utils.GlobalVars( unsafeHasPprDebug )
 
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as BS
@@ -450,6 +452,18 @@ defaultSDocContext = SDC
   , sdocUnitIdForUser               = ftext
   }
 
+traceSDocContext :: SDocContext
+-- Used for pprTrace, when we want to see lots of info
+traceSDocContext = defaultSDocContext
+  { sdocPprDebug                    = unsafeHasPprDebug
+  , sdocPrintTypecheckerElaboration = True
+  , sdocPrintExplicitKinds          = True
+  , sdocPrintExplicitCoercions      = True
+  , sdocPrintExplicitRuntimeReps    = True
+  , sdocPrintExplicitForalls        = True
+  , sdocPrintEqualityRelations      = True
+  }
+
 withPprStyle :: PprStyle -> SDoc -> SDoc
 {-# INLINE CONLIKE withPprStyle #-}
 withPprStyle sty d = SDoc $ \ctxt -> runSDoc d ctxt{sdocStyle=sty}