simplify substitution avoids shadowing

src/Convert/Cast.hs

@@ -92,10 +92,13 @@ traverseStmtM stmt = do
     return stmt'
 
 traverseExprM :: Expr -> ST Expr
-traverseExprM (Cast (Left (IntegerVector _ sg rs)) e) = do
+traverseExprM (Cast (Left (IntegerVector _ sg rs)) value) = do
-    e' <- traverseExprM e
+    value' <- traverseExprM value
-    convertCastM (dimensionsSize rs) e' signed
+    size' <- traverseExprM size
-    where signed = sg == Signed
+    convertCastM size' value' signed
+    where
+        signed = sg == Signed
+        size = dimensionsSize rs
 traverseExprM other =
     traverseSinglyNestedExprsM traverseExprM other
 

src/Convert/ExprUtils.hs

@@ -52,6 +52,8 @@ simplifyStep (Mux (Number n) e1 e2) =
         Just _ -> e1
         Nothing -> Mux (Number n) e1 e2
 
+simplifyStep (Call (Ident "$clog2") (Args [SizDec k] [])) =
+    simplifyStep $ Call (Ident "$clog2") (Args [RawNum k] [])
 simplifyStep (Call (Ident "$clog2") (Args [Dec k] [])) =
     toDec $ clog2 k
     where

src/Convert/Simplify.hs

@@ -32,22 +32,29 @@ convertDescription =
 
 traverseDeclM :: Decl -> Scoper Expr Decl
 traverseDeclM decl = do
-    case decl of
+    decl' <- traverseDeclExprsM traverseExprM decl
-        Param Localparam _ x e ->
+    case decl' of
-            when (isSimpleExpr e) $ insertElem x e
+        Param Localparam UnknownType x e ->
+            insertExpr x e
+        Param Localparam (Implicit Signed [(RawNum 31, RawNum 0)]) x e ->
+            insertExpr x e
+        Param Localparam (Implicit sg rs) x e ->
+            insertExpr x $ Cast (Left t) e
+            where t = IntegerVector TLogic sg rs
+        Param Localparam t x e ->
+            insertExpr x $ Cast (Left t) e
         _ -> return ()
-    let mi = MIPackageItem $ Decl decl
-    mi' <- traverseModuleItemM mi
-    let MIPackageItem (Decl decl') = mi'
     return decl'
 
+insertExpr :: Identifier -> Expr -> Scoper Expr ()
+insertExpr ident expr = do
+    expr' <- substituteExprM expr
+    when (isSimpleExpr expr') $ insertElem ident expr'
+
 isSimpleExpr :: Expr -> Bool
-isSimpleExpr Ident{}   = True
 isSimpleExpr Number{}  = True
 isSimpleExpr String{}  = True
-isSimpleExpr (Dot   e _  ) = isSimpleExpr e
+isSimpleExpr (Cast Left{} e) = isSimpleExpr e
-isSimpleExpr (Bit   e _  ) = isSimpleExpr e
-isSimpleExpr (Range e _ _) = isSimpleExpr e
 isSimpleExpr _ = False
 
 traverseModuleItemM :: ModuleItem -> Scoper Expr ModuleItem
@@ -117,11 +124,12 @@ convertExpr info expr =
 
 substitute :: Scopes Expr -> Expr -> Expr
 substitute scopes expr =
-    traverseNestedExprs substitute' expr
+    substitute' expr
     where
         substitute' :: Expr -> Expr
         substitute' (Ident x) =
             case lookupElem scopes x of
                 Nothing -> Ident x
                 Just (_, _, e) -> e
-        substitute' other = other
+        substitute' other =
+            traverseSinglyNestedExprs substitute' other

src/Convert/TypeOf.hs

@@ -115,7 +115,8 @@ traverseExprM (Cast (Right (Ident x)) expr) = do
         else elaborateSizeCast (Ident x) expr'
 traverseExprM (Cast (Right size) expr) = do
     expr' <- traverseExprM expr
-    elaborateSizeCast size expr'
+    size' <- traverseExprM size
+    elaborateSizeCast size' expr'
 traverseExprM other =
     traverseExprTypesM traverseTypeM other
     >>= traverseSinglyNestedExprsM traverseExprM

test/basic/simplify_scope.sv

@@ -0,0 +1,8 @@
+module top;
+    localparam A = 1;
+    localparam B = A;
+    if (A) begin : blk
+        localparam A = 1'sbx;
+        initial $display("%b", $clog2(B + 1 + 1));
+    end
+endmodule