Introduce predicate for when to enable source notes (needSourceNotes)

There were situations where we were using debugLevel == 0 as a proxy for
whether to retain source notes but -finfo-table-map also enables and
needs source notes so we should act consistently in both cases.

Ticket #20847

(cherry picked from commit 1316f7dadf0f538f09f8b97629c7e5f6f868266d)

4 files changed, 10 insertions, 8 deletions

diff --git a/compiler/GHC/CoreToStg/Prep.hs b/compiler/GHC/CoreToStg/Prep.hs
index b5dd0d7b2a..bd99bf976d 100644
--- a/compiler/GHC/CoreToStg/Prep.hs
+++ b/compiler/GHC/CoreToStg/Prep.hs
@@ -310,7 +310,7 @@ mkDataConWorkers dflags mod_loc data_tycons
    -- If we want to generate debug info, we put a source note on the
    -- worker. This is useful, especially for heap profiling.
    tick_it name
-     | debugLevel dflags == 0                = id
+     | not (needSourceNotes dflags)           = id
      | RealSrcSpan span _ <- nameSrcSpan name = tick span
      | Just file <- ml_hs_file mod_loc       = tick (span1 file)
      | otherwise                             = tick (span1 "???")
diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs
index aa951a13bd..50d393019c 100644
--- a/compiler/GHC/Driver/Session.hs
+++ b/compiler/GHC/Driver/Session.hs
@@ -42,6 +42,7 @@ module GHC.Driver.Session (
         DynamicTooState(..), dynamicTooState, setDynamicNow, setDynamicTooFailed,
         dynamicOutputFile, dynamicOutputHi,
         sccProfilingEnabled,
+        needSourceNotes,
         DynFlags(..),
         outputFile, hiSuf, objectSuf, ways,
         FlagSpec(..),
@@ -4910,6 +4911,11 @@ isBmi2Enabled dflags = case platformArch (targetPlatform dflags) of
 sccProfilingEnabled :: DynFlags -> Bool
 sccProfilingEnabled dflags = profileIsProfiling (targetProfile dflags)
 
+-- | Indicate whether we need to generate source notes
+needSourceNotes :: DynFlags -> Bool
+needSourceNotes dflags = debugLevel dflags > 0
+                       || gopt Opt_InfoTableMap dflags
+
 -- -----------------------------------------------------------------------------
 -- Linker/compiler information
 
diff --git a/compiler/GHC/HsToCore/Coverage.hs b/compiler/GHC/HsToCore/Coverage.hs
index 8a6bb4e160..2ba6dd3ae6 100644
--- a/compiler/GHC/HsToCore/Coverage.hs
+++ b/compiler/GHC/HsToCore/Coverage.hs
@@ -1047,17 +1047,13 @@ data TickTransEnv = TTE { fileName     :: FastString
 data TickishType = ProfNotes | HpcTicks | Breakpoints | SourceNotes
                  deriving (Eq)
 
-sourceNotesEnabled :: DynFlags -> Bool
-sourceNotesEnabled dflags =
-  (debugLevel dflags > 0) || (gopt Opt_InfoTableMap dflags)
-
 coveragePasses :: DynFlags -> [TickishType]
 coveragePasses dflags =
     ifa (breakpointsEnabled dflags)          Breakpoints $
     ifa (gopt Opt_Hpc dflags)                HpcTicks $
     ifa (sccProfilingEnabled dflags &&
          profAuto dflags /= NoProfAuto)      ProfNotes $
-    ifa (sourceNotesEnabled dflags)          SourceNotes []
+    ifa (needSourceNotes dflags)          SourceNotes []
   where ifa f x xs | f         = x:xs
                    | otherwise = xs
 
diff --git a/compiler/GHC/IfaceToCore.hs b/compiler/GHC/IfaceToCore.hs
index 6425ebfc7f..f9e6fe7eb2 100644
--- a/compiler/GHC/IfaceToCore.hs
+++ b/compiler/GHC/IfaceToCore.hs
@@ -1537,9 +1537,9 @@ tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
 tcIfaceExpr (IfaceTick tickish expr) = do
     expr' <- tcIfaceExpr expr
     -- If debug flag is not set: Ignore source notes
-    dbgLvl <- fmap debugLevel getDynFlags
+    need_notes <- needSourceNotes <$> getDynFlags
     case tickish of
-      IfaceSource{} | dbgLvl == 0
+      IfaceSource{} | not (need_notes)
                     -> return expr'
       _otherwise    -> do
         tickish' <- tcIfaceTickish tickish