From d57c9670905bb692424a69562fdd5cc2b8f7fe74 Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Sat, 28 Sep 2019 16:57:36 -0400
Subject: [PATCH] added partial support for implicitly sized arrays

---
 src/Language/SystemVerilog/Parser/Parse.y      |  1 +
 src/Language/SystemVerilog/Parser/ParseDecl.hs | 13 +++++++++++++
 test/basic/stream.sv                           |  3 +--
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/Language/SystemVerilog/Parser/Parse.y b/src/Language/SystemVerilog/Parser/Parse.y
index 9bf0117..c577dae 100644
--- a/src/Language/SystemVerilog/Parser/Parse.y
+++ b/src/Language/SystemVerilog/Parser/Parse.y
@@ -592,6 +592,7 @@ DeclOrStmtTokens(delim) :: { [DeclToken] }
   | "<=" opt(DelayOrEventControl) Expr                      delim  { [DTAsgnNBlk $2 $3] }
 DeclOrStmtToken :: { DeclToken }
   : ","            { DTComma }
+  | "[" "]"        { DTAutoDim }
   | PartSelect     { DTRange    $1 }
   | Identifier     { DTIdent    $1 }
   | Direction      { DTDir      $1 }
diff --git a/src/Language/SystemVerilog/Parser/ParseDecl.hs b/src/Language/SystemVerilog/Parser/ParseDecl.hs
index 6b5bcad..71e255c 100644
--- a/src/Language/SystemVerilog/Parser/ParseDecl.hs
+++ b/src/Language/SystemVerilog/Parser/ParseDecl.hs
@@ -46,6 +46,7 @@ import Language.SystemVerilog.AST
 -- [PUBLIC]: combined (irregular) tokens for declarations
 data DeclToken
     = DTComma
+    | DTAutoDim
     | DTAsgn     AsgnOp Expr
     | DTAsgnNBlk (Maybe Timing) Expr
     | DTRange    (PartSelectMode, Range)
@@ -384,10 +385,22 @@ takeRanges (token : tokens) =
     case token of
         DTRange (NonIndexed, r) -> (r         : rs, rest          )
         DTBit   s               -> (asRange s : rs, rest          )
+        DTAutoDim               ->
+            case rest of
+                (DTAsgn AsgnOpEq (Pattern l) : _) -> autoDim l
+                (DTAsgn AsgnOpEq (Concat  l) : _) -> autoDim l
+                _ ->               ([]            , token : tokens)
         _                       -> ([]            , token : tokens)
     where
         (rs, rest) = takeRanges tokens
         asRange s = (Number "0", BinOp Sub s (Number "1"))
+        autoDim :: [a] -> ([Range], [DeclToken])
+        autoDim l =
+            ((lo, hi) : rs, rest)
+            where
+                n = length l
+                lo = Number "0"
+                hi = Number $ show (n - 1)
 
 -- Matching DTAsgnNBlk here allows tripLookahead to work both for standard
 -- declarations and in `parseDTsAsDeclOrAsgn`, where we're checking for an
diff --git a/test/basic/stream.sv b/test/basic/stream.sv
index a856003..c60713d 100644
--- a/test/basic/stream.sv
+++ b/test/basic/stream.sv
@@ -6,8 +6,7 @@ module top;
         logic [3:0] data;
     } packet_t;
     initial begin
-        // TODO: Add support for implicitly sized arrays.
-        logic [1:0] array[4] = '{ 2'b10, 2'b01, 2'b11, 2'b00 };
+        logic [1:0] array[] = '{ 2'b10, 2'b01, 2'b11, 2'b00 };
         packet_t packet = {<<4{ {<<2{array}} }};
         $display("packet addr = %b", packet.addr);
         $display("packet data = %b", packet.data);