check for module or interface names used as type names

CHANGELOG.md

@@ -24,6 +24,7 @@
 * Port connection attributes (e.g., [pulp_soc.sv]) are now ignored with a
   warning rather than failing to parse
 * Improved error message when specifying an extraneous named port connection
+* Added checks for accidental usage of interface or module names as type names
 
 [pulp_soc.sv]: https://github.com/pulp-platform/pulp_soc/blob/0573a85c/rtl/pulp_soc/pulp_soc.sv#L733
 

src/Convert/Interface.hs

@@ -10,6 +10,7 @@ module Convert.Interface (convert) where
 import Data.List (intercalate, (\\))
 import Data.Maybe (isJust, isNothing, mapMaybe)
 import Control.Monad.Writer.Strict
+import Text.Read (readMaybe)
 import qualified Data.Map.Strict as Map
 
 import Convert.ExprUtils (endianCondExpr)
@@ -70,13 +71,26 @@ convertDescription parts (Part attrs extern Module lifetime name ports items) =
         traverseDeclM :: Decl -> Scoper [ModportDecl] Decl
         traverseDeclM decl = do
             case decl of
-                Variable  _ _ x _ _ -> insertElem x DeclVal
-                Net   _ _ _ _ x _ _ -> insertElem x DeclVal
-                Param     _ _ x _   -> insertElem x DeclVal
+                Variable  _ t x _ _ -> checkDeclType t x $ insertElem x DeclVal
+                Net   _ _ _ t x _ _ -> checkDeclType t x $ insertElem x DeclVal
+                Param     _ t x _   -> checkDeclType t x $ insertElem x DeclVal
                 ParamType _   x _   -> insertElem x DeclVal
                 CommentDecl{} -> return ()
             return decl
 
+        -- check for module or interface names used as type names
+        checkDeclType :: Type -> Identifier -> Scoper a b -> Scoper a b
+        checkDeclType (Alias typeName _) declName continue
+            | isNothing (readMaybe declName :: Maybe Int) = do
+            maybeType <- lookupElemM typeName
+            case (maybePart, maybeType) of
+                (Just part, Nothing{}) -> scopedErrorM $ "declaration " ++
+                    declName ++ " uses " ++ show (pKind part) ++ " name " ++
+                    typeName ++ " where a type name is expected"
+                _ -> continue
+            where maybePart = Map.lookup typeName parts
+        checkDeclType _ _ other = other
+
         lookupIntfElem :: Scopes [ModportDecl] -> Expr -> LookupResult [ModportDecl]
         lookupIntfElem modports expr =
             case lookupElem modports expr of
@@ -285,6 +299,7 @@ convertDescription parts (Part attrs extern Module lifetime name ports items) =
                     else if elem x (pPorts partInfo) then
                         tell [(x, info)] >> return decl
                     else
+                        -- TODO: This does not handle shadowed typenames.
                         scopedErrorM $
                             "Modport not in port list: " ++ show t ++ " " ++ x
                             ++ ". Is this an interface missing a port list?"

test/core/interface_name_shadow.sv

+interface I;
+    logic [3:0] x;
+endinterface
+module top;
+    I i();
+    if (1) begin : blk
+        typedef logic I;
+        var I i;
+        assign i = 0;
+    end
+    initial $display("%b %b", i.x, blk.i);
+endmodule

test/core/interface_name_shadow.v

+module top;
+    generate
+        if (1) begin : i
+            wire [3:0] x;
+        end
+        if (1) begin : blk
+            wire i;
+            assign i = 0;
+        end
+    endgenerate
+    initial $display("%b %b", i.x, blk.i);
+endmodule

test/error/interface_name_func.sv

+// pattern: declaration dst uses interface name I where a type name is expected
+// location: interface_name_func.sv:5:12
+interface I;
+    logic [3:0] x;
+    task t(I dst, I src);
+        dst.x <= src.x;
+    endtask
+endinterface
+module top;
+    I i();
+endmodule

test/error/interface_name_var.sv

+// pattern: declaration i uses interface name I where a type name is expected
+// location: interface_name_var.sv:7:12
+interface I;
+    logic [3:0] x;
+endinterface
+module top;
+    if (1) var I i;
+endmodule