prevent genvar conflict without changing scope tree

src/Convert/ForDecl.hs

@@ -24,11 +24,24 @@ convert =
     )
 
 convertGenItem :: GenItem -> GenItem
-convertGenItem (GenFor (True, x, e) a b mx c) =
-    GenBlock (fmap (++ "_for_decl") mx)
-    [ GenModuleItem $ Genvar x
-    , GenFor (False, x, e) a b mx c
-    ]
+convertGenItem (GenFor (True, x, e) a b mbx c) =
+    GenBlock Nothing genItems
+    where
+        x' = (maybe "" (++ "_") mbx) ++ x
+        Generate genItems =
+            traverseNestedModuleItems converter $ Generate $
+            [ GenModuleItem $ Genvar x'
+            , GenFor (False, x, e) a b mbx c
+            ]
+        converter =
+            (traverseExprs $ traverseNestedExprs convertExpr) .
+            (traverseLHSs  $ traverseNestedLHSs  convertLHS )
+        prefix :: String -> String
+        prefix ident = if ident == x then x' else ident
+        convertExpr (Ident ident) = Ident $ prefix ident
+        convertExpr other = other
+        convertLHS (LHSIdent ident) = LHSIdent $ prefix ident
+        convertLHS other = other
 convertGenItem other = other
 
 convertStmt :: Stmt -> Stmt

src/Convert/Traverse.hs

@@ -742,7 +742,17 @@ traverseLHSsM' strat mapper item =
                 Assertion a' -> AssertionItem (mx, a')
                 _ -> error $ "redirected AssertionItem traverse failed: "
                         ++ show converted
+        traverseModuleItemLHSsM (Generate items) = do
+            items' <- mapM (traverseNestedGenItemsM traverGenItemLHSsM) items
+            return $ Generate items'
         traverseModuleItemLHSsM other = return other
+        traverGenItemLHSsM (GenFor (n1, x1, e1) cc (x2, op2, e2) mn subItems) = do
+            wrapped_x1' <- (if n1 then return else mapper) $ LHSIdent x1
+            wrapped_x2' <- mapper $ LHSIdent x2
+            let LHSIdent x1' = wrapped_x1'
+            let LHSIdent x2' = wrapped_x2'
+            return $ GenFor (n1, x1', e1) cc (x2', op2, e2) mn subItems
+        traverGenItemLHSsM other = return other
 
 traverseLHSs' :: TFStrategy -> Mapper LHS -> Mapper ModuleItem
 traverseLHSs' strat = unmonad $ traverseLHSsM' strat

test/basic/for_decl.sv

@@ -3,11 +3,13 @@ module top;
     wire [0:31] a;
     for (genvar n = 0; n < 32; n++) begin : gen_filter
         assign a[n] = n & 1;
+        wire x;
+        assign x = a[n];
     end
 
     wire [0:31] b;
     for (genvar n = 0; n < 32; n++) begin : gen_filter_other
-        assign b[n] = ~a[n];
+        assign b[n] = ~gen_filter[n].x;
     end
 
     initial
@@ -58,4 +60,8 @@ module top;
         for (integer i = 0; i < 32; i++)
             $display("8: ", a[i], b[i]);
 
+    logic start;
+    assign start = gen_filter[0].x;
+    initial $display(start);
+
 endmodule

test/basic/for_decl.v

@@ -5,6 +5,8 @@ module top;
         genvar n;
         for (n = 0; n < 32; n = n + 1) begin : gen_filter
             assign a[n] = n & 1;
+            wire x;
+            assign x = a[n];
         end
     endgenerate
 
@@ -12,7 +14,7 @@ module top;
     generate
         genvar other_n;
         for (other_n = 0; other_n < 32; other_n = other_n + 1) begin : gen_filter_other
-            assign b[other_n] = ~a[other_n];
+            assign b[other_n] = ~gen_filter[other_n].x;
         end
     endgenerate
 
@@ -69,4 +71,8 @@ module top;
             $display("8: ", a[i], b[i]);
     end
 
+    wire start;
+    assign start = gen_filter[0].x;
+    initial $display(start);
+
 endmodule