[project @ 2001-07-11 19:48:07 by sof]

[ghc-hetmet.git] / ghc / compiler / stgSyn / StgLint.lhs

diff --git a/ghc/compiler/stgSyn/StgLint.lhs b/ghc/compiler/stgSyn/StgLint.lhs
index c0300a5..3692e06 100644 (file)
--- a/ghc/compiler/stgSyn/StgLint.lhs
+++ b/ghc/compiler/stgSyn/StgLint.lhs
@@ -10,19 +10,19 @@ module StgLint ( lintStgBindings ) where
 
 import StgSyn
 
-import Bag             ( Bag, emptyBag, isEmptyBag, snocBag, foldBag )
-import Id              ( Id, idType )
+import Bag             ( Bag, emptyBag, isEmptyBag, snocBag )
+import Id              ( Id, idType, isLocalId )
 import VarSet
 import DataCon         ( DataCon, dataConArgTys, dataConRepType )
 import PrimOp          ( primOpType )
 import Literal         ( literalType, Literal )
 import Maybes          ( catMaybes )
-import Name            ( isLocallyDefined, getSrcLoc )
+import Name            ( getSrcLoc )
 import ErrUtils                ( ErrMsg, Message, addErrLocHdrLine, pprBagOfErrors, dontAddErrLoc )
-import Type            ( mkFunTys, splitFunTys, splitAlgTyConApp_maybe, 
+import Type            ( mkFunTys, splitFunTys, splitTyConApp_maybe,
                          isUnLiftedType, isTyVarTy, splitForAllTys, Type
                        )
-import TyCon           ( TyCon, isDataTyCon )
+import TyCon           ( TyCon, isDataTyCon, tyConDataCons )
 import Util            ( zipEqual )
 import Outputable
 
@@ -33,6 +33,18 @@ Checks for
        (a) *some* type errors
        (b) locally-defined variables used but not defined
 
+
+Note: unless -dverbose-stg is on, display of lint errors will result
+in "panic: bOGUS_LVs".
+
+WARNING: 
+~~~~~~~~
+
+This module has suffered bit-rot; it is likely to yield lint errors
+for Stg code that is currently perfectly acceptable for code
+generation.  Solution: don't use it!  (KSW 2000-05).
+
+
 %************************************************************************
 %*                                                                     *
 \subsection{``lint'' for various constructs}
@@ -77,11 +89,11 @@ lintStgVar v  = checkInScope v      `thenL_`
 
 \begin{code}
 lintStgBinds :: StgBinding -> LintM [Id]               -- Returns the binders
-lintStgBinds (StgNonRec binder rhs)
+lintStgBinds (StgNonRec _srt binder rhs)
   = lint_binds_help (binder,rhs)       `thenL_`
     returnL [binder]
 
-lintStgBinds (StgRec pairs)
+lintStgBinds (StgRec _srt pairs)
   = addInScopeVars binders (
        mapL lint_binds_help pairs `thenL_`
        returnL binders
@@ -115,10 +127,10 @@ lint_binds_help (binder, rhs)
 \begin{code}
 lintStgRhs :: StgRhs -> LintM (Maybe Type)
 
-lintStgRhs (StgRhsClosure _ _ _ _ _ [] expr)
+lintStgRhs (StgRhsClosure _ _ _ _ [] expr)
   = lintStgExpr expr
 
-lintStgRhs (StgRhsClosure _ _ _ _ _ binders expr)
+lintStgRhs (StgRhsClosure _ _ _ _ binders expr)
   = addLoc (LambdaBodyOf binders) (
     addInScopeVars binders (
        lintStgExpr expr   `thenMaybeL` \ body_ty ->
@@ -154,7 +166,13 @@ lintStgExpr e@(StgConApp con args)
   where
     con_ty = dataConRepType con
 
-lintStgExpr e@(StgPrimApp op args _)
+lintStgExpr e@(StgOpApp (StgFCallOp _ _) args res_ty)
+  =    -- We don't have enough type information to check
+       -- the application; ToDo
+    mapMaybeL lintStgArg args  `thenL` \ maybe_arg_tys ->
+    returnL (Just res_ty)
+
+lintStgExpr e@(StgOpApp (StgPrimOp op) args _)
   = mapMaybeL lintStgArg args  `thenL` \ maybe_arg_tys ->
     case maybe_arg_tys of
       Nothing      -> returnL Nothing
@@ -184,8 +202,13 @@ lintStgExpr (StgSCC _ expr)        = lintStgExpr expr
 
 lintStgExpr e@(StgCase scrut _ _ bndr _ alts)
   = lintStgExpr scrut          `thenMaybeL` \ _ ->
-    checkTys (idType bndr) scrut_ty (mkDefltMsg bndr) `thenL_`
 
+    (case alts of
+       StgPrimAlts tc _ _       -> check_bndr tc
+       StgAlgAlts (Just tc) _ _ -> check_bndr tc
+       StgAlgAlts Nothing   _ _ -> returnL ()
+    )                                                  `thenL_`
+       
     (trace (showSDoc (ppr e)) $ 
        -- we only allow case of tail-call or primop.
     (case scrut of
@@ -194,12 +217,13 @@ lintStgExpr e@(StgCase scrut _ _ bndr _ alts)
        other -> addErrL (mkCaseOfCaseMsg e))   `thenL_`
 
     addInScopeVars [bndr] (lintStgAlts alts scrut_ty)
-  )
+    )
   where
-    scrut_ty = get_ty alts
-
-    get_ty (StgAlgAlts  ty _ _) = ty
-    get_ty (StgPrimAlts ty _ _) = ty
+    scrut_ty     = idType bndr
+    bad_bndr      = mkDefltMsg bndr
+    check_bndr tc = case splitTyConApp_maybe scrut_ty of
+                       Just (bndr_tc, _) -> checkL (tc == bndr_tc) bad_bndr
+                       Nothing           -> addErrL bad_bndr
 \end{code}
 
 \begin{code}
@@ -229,11 +253,10 @@ lintStgAlts alts scrut_ty
          check ty = checkTys first_ty ty (mkCaseAltMsg alts)
 
 lintAlgAlt scrut_ty (con, args, _, rhs)
-  = (case splitAlgTyConApp_maybe scrut_ty of
-      Nothing ->
-        addErrL (mkAlgAltMsg1 scrut_ty)
-      Just (tycon, tys_applied, cons) ->
+  = (case splitTyConApp_maybe scrut_ty of
+      Just (tycon, tys_applied) | isDataTyCon tycon ->
         let
+          cons    = tyConDataCons tycon
           arg_tys = dataConArgTys con tys_applied
                -- This almost certainly does not work for existential constructors
         in
@@ -242,6 +265,8 @@ lintAlgAlt scrut_ty (con, args, _, rhs)
                                                                 `thenL_`
         mapL check (zipEqual "lintAlgAlt:stg" arg_tys args)     `thenL_`
         returnL ()
+      other ->
+        addErrL (mkAlgAltMsg1 scrut_ty)
     )                                                           `thenL_`
     addInScopeVars args        (
         lintStgExpr rhs
@@ -363,7 +388,7 @@ addErr errs_so_far msg locs
   = errs_so_far `snocBag` mk_msg locs
   where
     mk_msg (loc:_) = let (l,hdr) = dumpLoc loc in addErrLocHdrLine l hdr msg
-    mk_msg []      = dontAddErrLoc "" msg
+    mk_msg []      = dontAddErrLoc msg
 
 addLoc :: LintLocInfo -> LintM a -> LintM a
 addLoc extra_loc m loc scope errs
@@ -377,8 +402,6 @@ addInScopeVars ids m loc scope errs
     -- a real error out of it...
     let
        new_set = mkVarSet ids
-
-       shadowed = scope `intersectVarSet` new_set
     in
 --  After adding -fliberate-case, Simon decided he likes shadowed
 --  names after all.  WDP 94/07
@@ -403,7 +426,7 @@ checkFunApp :: Type                     -- The function type
 checkFunApp fun_ty arg_tys msg loc scope errs
   = cfa res_ty expected_arg_tys arg_tys
   where
-    (_, de_forall_ty)   = splitForAllTys fun_ty
+    (_, de_forall_ty)         = splitForAllTys fun_ty
     (expected_arg_tys, res_ty) = splitFunTys de_forall_ty
 
     cfa res_ty expected []     -- Args have run out; that's fine
@@ -427,7 +450,7 @@ checkFunApp fun_ty arg_tys msg loc scope errs
 \begin{code}
 checkInScope :: Id -> LintM ()
 checkInScope id loc scope errs
-  = if isLocallyDefined id && not (id `elemVarSet` scope) then
+  = if isLocalId id && not (id `elemVarSet` scope) then
        ((), addErr errs (hsep [ppr id, ptext SLIT("is out of scope")]) loc)
     else
        ((), errs)