always construct conversion; more modular conversion approach

Convert.hs

@@ -4,106 +4,28 @@
  - SystemVerilog to Verilog conversion
  -}
 
--- XXX: Note that, for now, we're going to shove the first few conversions all
--- into this same file, more or less. As patterns start becoming clearer, we
--- should be making helpers to make traversing the AST much easier.
-
--- Regarding `logic` conversion: The SystemVerilog grammar has the concept of a
--- `data_declaration`, which seems to cover things much more generally. While
--- obviously `logic` can appear as module items or ports, they can also be
--- function arguments, for example.
-
 module Convert (convert) where
 
---import Data.List
-import Text.Printf
-import Data.Maybe
-import qualified Data.Set as Set
-import qualified Data.Map.Strict as Map
-
 import Language.SystemVerilog.AST
 
-data Possibility = AsWire | AsReg deriving (Eq, Ord)
-type Possibilities = Set.Set Possibility
-type TypeInfo = Map.Map String Possibilities
-type ModulePorts = Map.Map String [Direction]
+import qualified Convert.AlwaysKW
+import qualified Convert.Logic
 
--- TODO: It now seems like logic only becomes reg if it is assigned to in an
--- always block. If this is true, it obviously could dramatically simplify this
--- initial transformation.
+type Phase = [Module] -> [Module]
 
-convert :: [Module] -> [Module]
-convert modules = map (convertModule portsInfo) modules
-    where
-        portsInfo = Map.fromList $ map getPorts modules
-        getPorts :: Module -> (Identifier, [Direction])
-        getPorts (Module name ports items) =
-            let portDirMap = Map.fromList $ mapMaybe getDirection items
-            in (name, map (portDirMap Map.!) ports)
-            where
-                getDirection :: ModuleItem -> Maybe (Identifier, Direction)
-                getDirection (PortDecl dir _ ident) = Just (ident, dir)
-                getDirection _ = Nothing
+phases :: [Phase]
+phases =
+    [ Convert.AlwaysKW.convert
+    , Convert.Logic.convert
+    ]
 
-convertModule :: ModulePorts -> Module -> Module
-convertModule modules (Module name ports items) =
-    Module name ports (map (convertModuleItem info) items)
-    where
-        info = foldr (Map.unionWith Set.intersection) Map.empty (map (getTypeInfoModuleItem modules) items)
+run :: Phase
+run = foldr (.) id phases
 
-getLHSIdentifiers :: LHS -> [Identifier]
-getLHSIdentifiers (LHS       vx  ) = [vx]
-getLHSIdentifiers (LHSBit    vx _) = [vx]
-getLHSIdentifiers (LHSRange  vx _) = [vx]
-getLHSIdentifiers (LHSConcat lhss) = concat $ map getLHSIdentifiers lhss
-
-onlyAsWire :: Possibilities
-onlyAsWire = Set.fromList [AsWire]
-onlyAsReg  :: Possibilities
-onlyAsReg  = Set.fromList [AsReg]
-asEither   :: Possibilities
-asEither   = Set.fromList [AsWire, AsReg]
-
-getStmtLHSs :: Stmt -> [LHS]
-getStmtLHSs (Block _ stmts) = concat $ map getStmtLHSs stmts
-getStmtLHSs (Case e cases (Just stmt)) = (getStmtLHSs stmt) ++ (getStmtLHSs $ Case e cases Nothing)
-getStmtLHSs (Case _ cases Nothing) = concat $ map getStmtLHSs $ map snd cases
-getStmtLHSs (BlockingAssignment    lhs _) = [lhs]
-getStmtLHSs (NonBlockingAssignment lhs _) = [lhs]
-getStmtLHSs (For _ _ _ stmt) = getStmtLHSs stmt
-getStmtLHSs (If _ s1 s2) = (getStmtLHSs s1) ++ (getStmtLHSs s2)
-getStmtLHSs (Timing _ s) = getStmtLHSs s
-getStmtLHSs (Null) = []
-
-getTypeInfoModuleItem :: ModulePorts -> ModuleItem -> TypeInfo
-getTypeInfoModuleItem _ (Assign lhs _) =
-    Map.fromList $ zip (getLHSIdentifiers lhs) (repeat onlyAsWire)
-getTypeInfoModuleItem _ (AlwaysC _ stmt) =
-    Map.fromList $ zip idents (repeat onlyAsReg)
-    where
-        lhss = getStmtLHSs stmt
-        idents = concat $ map getLHSIdentifiers lhss
---getTypeInfoModuleItem modules (Instance name _ _ bindings) =
---    case Map.lookup name modules of
---        Nothing -> Map.empty
---        Just dirs ->
---
---            where
---                isDirect :: PortBinding -> Bool
---                isDirect x = snd x == Nothing
---                directs = map fst $ filter isDirect bindings
---getTypeInfoModuleItem _ (Function   (Maybe FuncRet) Identifier [(Bool, BlockItemDeclaration)] Stmt
---getTypeInfoModuleItem _ (Generate   [GenItem]
-getTypeInfoModuleItem _ _ = Map.empty
-
-convertModuleItem :: TypeInfo -> ModuleItem -> ModuleItem
-convertModuleItem info (LocalNet (Logic mr) ident val) =
-    LocalNet (t mr) ident val
-    where
-        t = case Map.lookup ident info of
-            Nothing -> Wire
-            Just possibilities ->
-                if Set.member AsWire possibilities then Wire
-                else if Set.member AsReg possibilities then Reg
-                else error $ printf "item %s has not possibilities" ident
-convertModuleItem _ other = other
+convert :: Phase
+convert modules =
+    let modules' = run modules
+    in
+        if modules == modules'
+            then modules
+            else convert modules'

Convert/AlwaysKW.hs

@@ -0,0 +1,25 @@
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Conversion for `always_comb` and `always_ff`
+ -}
+
+module Convert.AlwaysKW (convert) where
+
+import Convert.Template.ModuleItem (moduleItemConverter)
+
+import Language.SystemVerilog.AST
+
+convert :: [Module] -> [Module]
+convert = moduleItemConverter convertModuleItem
+
+-- Conversions:
+-- `always_comb` -> `always @*`
+-- `always_ff` -> `always`
+
+convertModuleItem :: ModuleItem -> ModuleItem
+convertModuleItem (AlwaysC AlwaysComb stmt) =
+    AlwaysC Always $ Timing SenseStar stmt
+convertModuleItem (AlwaysC AlwaysFF stmt) =
+    AlwaysC Always stmt
+convertModuleItem other = other

Convert/Logic.hs

@@ -0,0 +1,61 @@
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Conversion for `logic`
+ -}
+
+-- Regarding `logic` conversion: The SystemVerilog grammar has the concept of a
+-- `data_declaration`, which seems to cover things much more generally. While
+-- obviously `logic` can appear as module items or ports, they can also be
+-- function arguments, for example.
+
+-- It seems like logic only becomes reg if it is assigned to in an always block.
+
+module Convert.Logic (convert) where
+
+import qualified Data.Set as Set
+
+import Language.SystemVerilog.AST
+
+type RegIdents = Set.Set String
+
+convert :: [Module] -> [Module]
+convert modules = map convertModule modules
+
+convertModule :: Module -> Module
+convertModule (Module name ports items) =
+    Module name ports $ map (convertModuleItem idents) items
+    where
+        idents = Set.unions $ map getRegIdents items
+
+getStmtLHSs :: Stmt -> [LHS]
+getStmtLHSs (Block _ stmts) = concat $ map getStmtLHSs stmts
+getStmtLHSs (Case e cases (Just stmt)) = (getStmtLHSs stmt) ++ (getStmtLHSs $ Case e cases Nothing)
+getStmtLHSs (Case _ cases Nothing) = concat $ map getStmtLHSs $ map snd cases
+getStmtLHSs (BlockingAssignment    lhs _) = [lhs]
+getStmtLHSs (NonBlockingAssignment lhs _) = [lhs]
+getStmtLHSs (For _ _ _ stmt) = getStmtLHSs stmt
+getStmtLHSs (If _ s1 s2) = (getStmtLHSs s1) ++ (getStmtLHSs s2)
+getStmtLHSs (Timing _ s) = getStmtLHSs s
+getStmtLHSs (Null) = []
+
+getLHSIdents :: LHS -> [Identifier]
+getLHSIdents (LHS       vx  ) = [vx]
+getLHSIdents (LHSBit    vx _) = [vx]
+getLHSIdents (LHSRange  vx _) = [vx]
+getLHSIdents (LHSConcat lhss) = concat $ map getLHSIdents lhss
+
+getRegIdents :: ModuleItem -> RegIdents
+getRegIdents (AlwaysC _ stmt) =
+    Set.fromList idents
+    where
+        lhss = getStmtLHSs stmt
+        idents = concat $ map getLHSIdents lhss
+getRegIdents _ = Set.empty
+
+convertModuleItem :: RegIdents -> ModuleItem -> ModuleItem
+convertModuleItem idents (LocalNet (Logic mr) ident val) =
+    LocalNet (t mr) ident val
+    where
+        t = if Set.member ident idents then Reg else Wire
+convertModuleItem _ other = other

Convert/Template/ModuleItem.hs

@@ -0,0 +1,44 @@
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Template converter for ModuleItem transformations
+ -
+ - Also has coverage for ModuleItems inside of generate blocks
+ -}
+
+module Convert.Template.ModuleItem (moduleItemConverter) where
+
+import Data.Maybe
+import Language.SystemVerilog.AST
+
+type Converter = ModuleItem -> ModuleItem
+
+moduleItemConverter :: Converter -> ([Module] -> [Module])
+moduleItemConverter f = convert f
+
+convert :: Converter -> [Module] -> [Module]
+convert f modules = map (convertModule f) modules
+
+convertModule :: Converter -> Module -> Module
+convertModule f (Module name ports items) =
+    Module name ports $ map (convertModuleItem f) items
+
+convertModuleItem :: Converter -> ModuleItem -> ModuleItem
+convertModuleItem f (Generate items) = f $ Generate $ map (convertGenItem f) items
+convertModuleItem f other = f other
+
+convertGenItem :: Converter -> GenItem -> GenItem
+convertGenItem f item = convertGenItem' item
+    where
+        convertGenItem' :: GenItem -> GenItem
+        convertGenItem' (GenBlock x items) = GenBlock x $ map convertGenItem' items
+        convertGenItem' (GenFor a b c d items) = GenFor a b c d $ map convertGenItem' items
+        convertGenItem' (GenIf e i1 i2) = GenIf e (convertGenItem' i1) (convertGenItem' i2)
+        convertGenItem' (GenNull) = GenNull
+        convertGenItem' (GenModuleItem moduleItem) = GenModuleItem $ f moduleItem
+        convertGenItem' (GenCase e cases def) = GenCase e cases' def'
+            where
+                cases' = zip (map fst cases) (map (convertGenItem' . snd) cases)
+                def' = if def == Nothing
+                    then Nothing
+                    else Just $ convertGenItem' $ fromJust def

sv2v.cabal

@@ -60,6 +60,9 @@ executable sv2v
     Language.SystemVerilog.Parser.Preprocess
     Language.SystemVerilog.Parser.Tokens
     Convert
+    Convert.AlwaysKW
+    Convert.Logic
+    Convert.Template.ModuleItem
   ghc-options:
     -O3
     -threaded