handle naming and scoping of unnamed generate blocks

src/Convert.hs

@@ -47,6 +47,7 @@ import qualified Convert.Typedef
 import qualified Convert.TypeOf
 import qualified Convert.UnbasedUnsized
 import qualified Convert.Unique
+import qualified Convert.UnnamedGenBlock
 import qualified Convert.UnpackedArray
 import qualified Convert.Unsigned
 import qualified Convert.Wildcard
@@ -105,6 +106,7 @@ initialPhases selectExclude =
     , Convert.Package.convert
     , Convert.ParamNoDefault.convert
     , Convert.ResolveBindings.convert
+    , Convert.UnnamedGenBlock.convert
     ]
 
 convert :: [Job.Exclude] -> Phase

src/Convert/Interface.hs

@@ -341,7 +341,7 @@ inlineInstance global ranges modportBindings items partName
     comment :
     map (MIPackageItem . Decl) bindingBaseParams ++
     map (MIPackageItem . Decl) parameterBinds ++
-    (wrapInstance $ GenBlock instanceName $ map GenModuleItem items')
+    wrapInstance instanceName items'
     : portBindings
     where
         items' = evalScoper
@@ -367,11 +367,20 @@ inlineInstance global ranges modportBindings items partName
 
         comment = MIPackageItem $ Decl $ CommentDecl $
             "expanded " ++ inlineKind ++ " instance: " ++ instanceName
-        portBindings = mapMaybe portBindingItem $
+        portBindings =
+            wrapPortBindings $
+            map portBindingItem $
+            filter ((/= Nil) . snd) $
             filter notSubstituted instancePorts
         notSubstituted :: PortBinding -> Bool
         notSubstituted (portName, _) =
             lookup portName modportBindings == Nothing
+        wrapPortBindings :: [ModuleItem] -> [ModuleItem]
+        wrapPortBindings =
+            if isArray
+                then (\x -> [x]) . wrapInstance blockName
+                else id
+            where blockName = instanceName ++ "_port_bindings"
 
         rewriteItem :: ModuleItem -> ModuleItem
         rewriteItem =
@@ -573,10 +582,8 @@ inlineInstance global ranges modportBindings items partName
                         ++ " expected type, found expr: " ++ show e'
         overrideParam other = other
 
-        portBindingItem :: PortBinding -> Maybe ModuleItem
+        portBindingItem :: PortBinding -> ModuleItem
-        portBindingItem (_, Nil) = Nothing
         portBindingItem (ident, expr) =
-            Just $ wrapInstance $ GenModuleItem $
             if findDeclDir ident == Input
                 then bind (LHSDot (inj LHSBit LHSIdent) ident) expr
                 else bind (toLHS expr) (Dot (inj Bit Ident) ident)
@@ -614,8 +621,8 @@ inlineInstance global ranges modportBindings items partName
         [arrayRange @ (arrayLeft, arrayRight)] = ranges
 
         -- wrap the given item in a generate loop if necessary
-        wrapInstance :: GenItem -> ModuleItem
+        wrapInstance :: Identifier -> [ModuleItem] -> ModuleItem
-        wrapInstance item =
+        wrapInstance blockName moduleItems =
             Generate $
             if not isArray then
                 [item]
@@ -624,6 +631,7 @@ inlineInstance global ranges modportBindings items partName
                 , GenFor inits cond incr item
                 ]
             where
+                item = GenBlock blockName $ map GenModuleItem moduleItems
                 inits = (loopVar, arrayLeft)
                 cond = endianCondExpr arrayRange
                     (BinOp Ge (Ident loopVar) arrayRight)

src/Convert/Scoper.hs

@@ -512,8 +512,6 @@ scopeModuleItemT declMapper moduleItemMapper genItemMapper stmtMapper =
             fullModuleItemMapper item >>= return . MIAttr attr
         fullModuleItemMapper item = moduleItemMapper item
 
-        -- TODO: This doesn't yet support implicit naming of generate blocks as
-        -- blocks as described in Section 27.6.
         fullGenItemMapper :: GenItem -> ScoperT a m GenItem
         fullGenItemMapper genItem = do
             genItem' <- genItemMapper genItem
@@ -524,7 +522,7 @@ scopeModuleItemT declMapper moduleItemMapper genItemMapper stmtMapper =
                     injected' <- mapM fullModuleItemMapper injected
                     genItem'' <- scopeGenItemMapper genItem'
                     let genItems = map GenModuleItem injected' ++ [genItem'']
-                    return $ GenBlock "" genItems
+                    return $ GenBlock "" genItems -- flattened during traversal
         scopeGenItemMapper :: GenItem -> ScoperT a m GenItem
         scopeGenItemMapper (GenFor (index, a) b c genItem) = do
             genItem' <- scopeGenItemBranchMapper index genItem

src/Convert/UnnamedGenBlock.hs

@@ -0,0 +1,121 @@
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Labels any unnamed generate blocks, per IEEE 1800-2017 Section 27.6
+ -
+ - This transformation is performed before any others, and is only performed
+ - once. The AST traversal utilities are not used here to avoid the automatic
+ - elaboration they perform.
+ -}
+
+module Convert.UnnamedGenBlock (convert) where
+
+import Control.Monad.State.Strict
+import Data.List (isPrefixOf)
+
+import Language.SystemVerilog.AST
+
+convert :: [AST] -> [AST]
+convert = map $ map traverseDescription
+
+traverseDescription :: Description -> Description
+traverseDescription (Part attrs extern kw lifetime name ports items) =
+    Part attrs extern kw lifetime name ports $
+        evalState (mapM traverseModuleItemM items) initialState
+traverseDescription other = other
+
+type S = State Info
+type Info = ([Identifier], Int)
+
+initialState :: Info
+initialState = ([], 1)
+
+traverseModuleItemM :: ModuleItem -> S ModuleItem
+traverseModuleItemM (item @ (Genvar x)) = declaration x item
+traverseModuleItemM (item @ (NInputGate  _ _ x _ _)) = declaration x item
+traverseModuleItemM (item @ (NOutputGate _ _ x _ _)) = declaration x item
+traverseModuleItemM (item @ (Instance    _ _ x _ _)) = declaration x item
+traverseModuleItemM (MIPackageItem (Decl decl)) =
+    traverseDeclM decl >>= return . MIPackageItem . Decl
+traverseModuleItemM (MIAttr attr item) =
+    traverseModuleItemM item >>= return . MIAttr attr
+traverseModuleItemM (Generate items) =
+    mapM traverseGenItemM items >>= return . Generate
+traverseModuleItemM item = return item
+
+-- add a declaration to the conflict list
+traverseDeclM :: Decl -> S Decl
+traverseDeclM decl =
+    case decl of
+        Variable  _ _ x _ _ -> declaration x decl
+        Param     _ _ x _   -> declaration x decl
+        ParamType _   x _   -> declaration x decl
+        CommentDecl{} -> return decl
+
+-- label the generate blocks within an individual generate item which is already
+-- in a list of generate items (top level or generate block)
+traverseGenItemM :: GenItem -> S GenItem
+traverseGenItemM (item @ GenIf{}) = do
+    item' <- labelGenElse item
+    incrCount >> return item'
+traverseGenItemM (item @ GenBlock{}) = do
+    item' <- labelBlock item
+    incrCount >> return item'
+traverseGenItemM (GenFor a b c item) = do
+    item' <- labelBlock item
+    incrCount >> return (GenFor a b c item')
+traverseGenItemM (GenCase expr cases) = do
+    let (exprs, items) = unzip cases
+    items' <- mapM labelBlock items
+    let cases' = zip exprs items'
+    incrCount >> return (GenCase expr cases')
+traverseGenItemM (GenModuleItem item) =
+    traverseModuleItemM item >>= return . GenModuleItem
+traverseGenItemM GenNull = return GenNull
+
+-- increment the counter each time a generate construct is encountered
+incrCount :: S ()
+incrCount = modify' $ \(idents, count) -> (idents, count + 1)
+
+genblk :: Identifier
+genblk = "genblk"
+
+-- adds the given identifier to the list of possible identifier conflicts, if
+-- necessary, and then returns the second argument as a shorthand courtesy
+declaration :: Identifier -> a -> S a
+declaration x a = do
+    when (genblk `isPrefixOf` x) $ do
+        let ident = drop (length genblk) x
+        modify' $ \(idents, count) -> (ident : idents, count)
+    return a
+
+-- generate a locally unique gen block name
+makeBlockName :: S Identifier
+makeBlockName = do
+    (idents, count) <- get
+    let uniqueSuffix = prependZeroes idents (show count)
+    return $ genblk ++ uniqueSuffix
+
+-- prepend zeroes until the string isn't in the list
+prependZeroes :: [String] -> String -> String
+prependZeroes xs x | notElem x xs = x
+prependZeroes xs x = prependZeroes xs ('0' : x)
+
+-- if the item is a generate conditional item, give its `then` block and any
+-- direct `else if` blocks the same name
+labelGenElse :: GenItem -> S GenItem
+labelGenElse (GenIf cond thenItem elseItem) = do
+    thenItem' <- labelBlock thenItem
+    elseItem' <- labelGenElse elseItem
+    return $ GenIf cond thenItem' elseItem'
+labelGenElse other = labelBlock other
+
+-- transform the given item into a named generate block
+labelBlock :: GenItem -> S GenItem
+labelBlock (GenBlock "" items) =
+    makeBlockName >>= labelBlock . flip GenBlock items
+labelBlock (GenBlock x items) =
+    return $ GenBlock x $
+        evalState (mapM traverseGenItemM items) initialState
+labelBlock GenNull = return GenNull
+labelBlock item = labelBlock $ GenBlock "" [item]

src/Language/SystemVerilog/Parser/Parse.y

@@ -1352,6 +1352,7 @@ GenItems :: { [GenItem] }
 GenItem :: { GenItem }
   : GenBlock              { uncurry GenBlock $1 }
   | NonGenerateModuleItem { genItemsToGenItem $ map GenModuleItem $1 }
+  | "generate" GenItems "endgenerate" { genItemsToGenItem $2 }
   | ConditionalGenerateConstruct { $1 }
   | LoopGenerateConstruct        { $1 }
 ConditionalGenerateConstruct :: { GenItem }
@@ -1375,7 +1376,7 @@ GenCase :: { GenCase }
   | "default" opt(":") GenItemOrNull { ([], $3) }
 
 GenvarInitialization :: { Expr -> (Identifier, AsgnOp, Expr) -> GenItem -> GenItem }
-  : "genvar" Identifier "=" Expr { \a b c -> GenBlock "" [GenModuleItem (Genvar $2), GenFor ($2, $4) a b c] }
+  : "genvar" Identifier "=" Expr { \a b c -> genItemsToGenItem [GenModuleItem (Genvar $2), GenFor ($2, $4) a b c] }
   |          Identifier "=" Expr { GenFor ($1, $3) }
 
 GenvarIteration :: { (Identifier, AsgnOp, Expr) }
@@ -1480,7 +1481,7 @@ parseError a = case a of
 
 genItemsToGenItem :: [GenItem] -> GenItem
 genItemsToGenItem [x] = x
-genItemsToGenItem xs = GenBlock "" xs
+genItemsToGenItem xs = GenModuleItem $ Generate xs
 
 combineDeclsAndStmts :: ([Decl], [Stmt]) -> ([Decl], [Stmt]) ->
   ParseState ([Decl], [Stmt])

sv2v.cabal

@@ -99,6 +99,7 @@ executable sv2v
     Convert.TypeOf
     Convert.UnbasedUnsized
     Convert.Unique
+    Convert.UnnamedGenBlock
     Convert.UnpackedArray
     Convert.Unsigned
     Convert.Wildcard

test/basic/genblk_implicit.sv

@@ -0,0 +1,7 @@
+module top;
+    if (1) begin
+        // should not be visible in a top-level VCD
+        wire x;
+        assign x = 1;
+    end
+endmodule

test/basic/unnamed_genblk.sv

@@ -0,0 +1,55 @@
+// This test was adapted from Section 27.6 of IEEE 1800-2017
+
+module mod;
+    initial $dumpvars(0, mod);
+    // needed because of steveicarus/iverilog#528
+    `ifdef __ICARUS__
+        `define BEGIN(name) begin : name
+        `define END end
+    `else
+        `define BEGIN(name)
+        `define END
+    `endif
+
+    parameter genblk2 = 0;
+    genvar i;
+
+    // The following generate block is implicitly named genblk1
+
+    if (genblk2) `BEGIN(genblk1) logic a; `END // mod.genblk1.a
+    else `BEGIN(genblk1) logic b; `END // mod.genblk1.b
+
+    // The following generate block is implicitly named genblk02
+    // as genblk2 is already a declared identifier
+
+    if (genblk2) `BEGIN(genblk02) logic a; `END // mod.genblk02.a
+    else `BEGIN(genblk02) logic b; `END // mod.genblk02.b
+
+    // The following generate block would have been named genblk3
+    // but is explicitly named g1
+
+    for (i = 0; i < 1; i = i + 1) begin : g1 // block name
+        // The following generate block is implicitly named genblk1
+        // as the first nested scope inside g1
+        if (1) `BEGIN(genblk1) logic a; `END // mod.g1[0].genblk1.a
+    end
+
+    // The following generate block is implicitly named genblk4 since
+    // it belongs to the fourth generate construct in scope "mod".
+    // The previous generate block would have been
+    // named genblk3 if it had not been explicitly named g1
+
+    for (i = 0; i < 1; i = i + 1) `BEGIN(genblk4)
+        // The following generate block is implicitly named genblk1
+        // as the first nested generate block in genblk4
+        if (1) `BEGIN(genblk1) logic a; `END // mod.genblk4[0].genblk1.a
+    `END
+
+    // The following generate block is implicitly named genblk5
+    if (1) `BEGIN(genblk5) logic a; `END // mod.genblk5.a
+endmodule
+
+module top;
+    mod #(0) m0();
+    mod #(1) m1();
+endmodule

test/basic/unnamed_genblk_cascade.sv

@@ -0,0 +1,45 @@
+module example;
+    parameter P = 0;
+
+// needed because of steveicarus/iverilog#528
+`ifdef __ICARUS__
+    `define BEGIN begin : `BLK
+    `define END end
+`else
+    `define BEGIN
+    `define END
+`endif
+
+`define BLK genblk1
+         if (P == 1) `BEGIN integer w = 1; `END
+    else if (P == 2) `BEGIN integer x = 2; `END
+    else if (P == 3) `BEGIN integer y = 3; `END
+    else             `BEGIN integer z = 9; `END
+
+`undef BLK
+`define BLK genblk2
+    case (P)
+        1      : `BEGIN integer w = 1; `END
+        2      : `BEGIN integer x = 2; `END
+        3      : `BEGIN integer y = 3; `END
+        default: `BEGIN integer z = 9; `END
+    endcase
+
+`undef BLK
+`define BLK genblk3
+    if (1) `BEGIN wire a = 1; `END
+endmodule
+
+module top;
+`define TEST(i, v) \
+    example #(i) e``i(); \
+    initial #i begin \
+        $display(`"e``i.genblk1.v: %0d`", e``i.genblk1.v); \
+        $display(`"e``i.genblk2.v: %0d`", e``i.genblk2.v); \
+        $display(`"e``i.genblk3.a: %0d`", e``i.genblk3.a); \
+    end
+    `TEST(1, w)
+    `TEST(2, x)
+    `TEST(3, y)
+    `TEST(4, z)
+endmodule

test/core/unnamed_genblk_zeroes.sv

@@ -0,0 +1,37 @@
+module example;
+    initial $display("example");
+endmodule
+
+module top;
+    wire genblk1;
+    wire genblk33;
+    (* foo = 1 *) wire genblk01;
+    genvar genblk001;
+    example genblk0001();
+
+    wire x, y;
+    wire o1, o2, o3;
+    and genblk00001(o1, x, y);
+    not genblk000001(o2, o3, o1);
+
+    parameter genblk0000001 = 1;
+`ifndef REF
+    typedef logic genblk00000001;
+`endif
+
+`define BLK genblk000000001
+
+    if (1) begin
+`ifdef REF
+        : `BLK
+    reg
+`else
+    genblk00000001
+`endif
+        x = genblk0000001;
+    end
+    initial begin
+        `BLK.x = 1;
+        $display("%b", `BLK.x);
+    end
+endmodule

test/core/unnamed_genblk_zeroes.v

@@ -0,0 +1,2 @@
+`define REF
+`include "unnamed_genblk_zeroes.sv"