[Git][ghc/ghc][wip/sptentry-use-name] compiler: only use `Name` instead of `Id` in `SptEntry`

13 Aug 2025


      Cheng Shao pushed to branch wip/sptentry-use-name at Glasgow Haskell Compiler / GHC


Commits:
c4ab3b82 by Cheng Shao at 2025-08-13T01:05:04+02:00
compiler: only use `Name` instead of `Id` in `SptEntry`

As a part of #26298, this patch refactors `SptEntry` to only carry a
`Name` instead of `Id`: we do not care about extra information like
caffyness or type at all in any static pointer related codegen logic.
This is necessary to make `SptEntry` serializable, as a part of the
grand plan of serializable bytecode.

Co-authored-by: Codex <codex@openai.com>

- - - - -


4 changed files:

- compiler/GHC/Driver/Main.hs
- compiler/GHC/Iface/Tidy/StaticPtrTable.hs
- compiler/GHC/StgToJS/StaticPtr.hs
- compiler/GHC/Types/SptEntry.hs


Changes:

=====================================
compiler/GHC/Driver/Main.hs
=====================================
@@ -2547,9 +2547,9 @@ hscAddSptEntries :: HscEnv -> [SptEntry] -> IO ()
 hscAddSptEntries hsc_env entries = do
     let interp = hscInterp hsc_env
     let add_spt_entry :: SptEntry -> IO ()
-        add_spt_entry (SptEntry i fpr) = do
+        add_spt_entry (SptEntry n fpr) = do
             -- These are only names from the current module
-            (val, _, _) <- loadName interp hsc_env (idName i)
+            (val, _, _) <- loadName interp hsc_env n
             addSptEntry interp fpr val
     mapM_ add_spt_entry entries
 


=====================================
compiler/GHC/Iface/Tidy/StaticPtrTable.hs
=====================================
@@ -144,6 +144,7 @@ import GHC.Utils.Outputable as Outputable
 import GHC.Linker.Types
 
 import GHC.Types.Id
+import GHC.Types.Id.Info ( CafInfo(..) )
 import GHC.Types.ForeignStubs
 import GHC.Data.Maybe
 import GHC.Data.FastString
@@ -205,7 +206,7 @@ sptCreateStaticBinds opts this_mod binds = do
         Nothing      -> return (Nothing, (b, e))
         Just (_, t, info, arg) -> do
           (fp, e') <- mkStaticBind t info arg
-          return (Just (SptEntry b fp), (b, foldr Lam e' tvs))
+          return (Just (SptEntry (idName b) fp), (b, foldr Lam e' tvs))
 
     mkStaticBind :: Type -> CoreExpr -> CoreExpr
                  -> StateT Int IO (Fingerprint, CoreExpr)
@@ -256,12 +257,14 @@ sptModuleInitCode platform this_mod entries
     init_fn_body = vcat
         [  text "static StgWord64 k" <> int i <> text "[2] = "
            <> pprFingerprint fp <> semi
+        -- MayHaveCafRefs/NoCafRefs wouldn't make any difference here,
+        -- they doesn't affect the pretty-printed CLabel
         $$ text "extern StgPtr "
-           <> (pprCLabel platform $ mkClosureLabel (idName n) (idCafInfo n)) <> semi
+           <> (pprCLabel platform $ mkClosureLabel n MayHaveCafRefs) <> semi
         $$ text "hs_spt_insert" <> parens
              (hcat $ punctuate comma
                 [ char 'k' <> int i
-                , char '&' <> pprCLabel platform (mkClosureLabel (idName n) (idCafInfo n))
+                , char '&' <> pprCLabel platform (mkClosureLabel n MayHaveCafRefs)
                 ]
              )
         <> semi


=====================================
compiler/GHC/StgToJS/StaticPtr.hs
=====================================
@@ -9,20 +9,35 @@ import GHC.Prelude
 import GHC.Linker.Types (SptEntry(..))
 import GHC.Fingerprint.Type
 import GHC.Types.Literal
+import GHC.Types.Name
 
 import GHC.JS.JStg.Syntax
 import GHC.JS.Make
+import GHC.JS.Ident (name)
 
 import GHC.StgToJS.Symbols
-import GHC.StgToJS.Ids
 import GHC.StgToJS.Literal
 import GHC.StgToJS.Types
+import GHC.Utils.Panic (panic)
 
 initStaticPtrs :: [SptEntry] -> G JStgStat
 initStaticPtrs ptrs = mconcat <$> mapM initStatic ptrs
   where
-    initStatic (SptEntry sp_id (Fingerprint w1 w2)) = do
-      i <- varForId sp_id
+    -- Build a reference to the closure variable for a top-level Name.
+    -- Static pointer bindings are exported, so we can construct the symbol
+    -- directly from the Name's module and OccName.
+    varForName :: Name -> G JStgExpr
+    varForName n = do
+      case nameModule_maybe n of
+        Just m  -> do
+          let sym = mkJsSymbol True m (occNameMangledFS (nameOccName n))
+          pure (ValExpr (JVar (name sym)))
+        Nothing ->
+          -- Shouldn't happen for SPT entries
+          panic "varForName: non-external Name in SptEntry"
+
+    initStatic (SptEntry sp_name (Fingerprint w1 w2)) = do
+      i <- varForName sp_name
       fpa <- concat <$> mapM (genLit . mkLitWord64 . fromIntegral) [w1,w2]
       let sptInsert = ApplStat hdHsSptInsert (fpa ++ [i])
       return $ (hdInitStatic .^ "push") `ApplStat` [Func [] sptInsert]


=====================================
compiler/GHC/Types/SptEntry.hs
=====================================
@@ -3,14 +3,13 @@ module GHC.Types.SptEntry
   )
 where
 
-import GHC.Types.Var           ( Id )
+import GHC.Types.Name          ( Name )
 import GHC.Fingerprint.Type    ( Fingerprint )
 import GHC.Utils.Outputable
 
 -- | An entry to be inserted into a module's static pointer table.
 -- See Note [Grand plan for static forms] in "GHC.Iface.Tidy.StaticPtrTable".
-data SptEntry = SptEntry Id Fingerprint
+data SptEntry = SptEntry !Name !Fingerprint
 
 instance Outputable SptEntry where
-  ppr (SptEntry id fpr) = ppr id <> colon <+> ppr fpr
-
+  ppr (SptEntry n fpr) = ppr n <> colon <+> ppr fpr



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/c4ab3b82943744e264a962c0cc03d2e0...

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/c4ab3b82943744e264a962c0cc03d2e0...
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Cheng Shao (＠TerrorJack)

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