From c21077bf1e4edf5c72af558e500f93145bfccf0c Mon Sep 17 00:00:00 2001
From: John Demme <john.demme@microsoft.com>
Date: Fri, 14 Jul 2023 13:36:01 -0700
Subject: [PATCH] [HW][SV] Move string type from SV to HW (#5588)

Closes #5576.

Moving this since in the (near) future the verif dialect and HW module parameterization will be using string types.
---
 include/circt/Dialect/HW/HWTypes.td           | 7 +++++++
 include/circt/Dialect/SV/SVExpressions.td     | 3 ++-
 include/circt/Dialect/SV/SVTypes.td           | 7 -------
 test/Conversion/ExportVerilog/sv-dialect.mlir | 4 ++--
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/include/circt/Dialect/HW/HWTypes.td b/include/circt/Dialect/HW/HWTypes.td
index ac3fac170f59..cdc92d485072 100644
--- a/include/circt/Dialect/HW/HWTypes.td
+++ b/include/circt/Dialect/HW/HWTypes.td
@@ -76,6 +76,13 @@ def HWAggregateType : DialectType<HWDialect,
 // Type Definitions
 //===----------------------------------------------------------------------===//
 
+def HWStringType : TypeDef<HWDialect, "String"> {
+  let summary = "String type";
+  let description = "Defines a string type for the hw-centric dialects";
+
+  let mnemonic = "string";
+}
+
 /// Points to a name within a module.
 def HWInnerRefAttr : Attr<
   CPred<"$_self.isa<::circt::hw::InnerRefAttr>()">,
diff --git a/include/circt/Dialect/SV/SVExpressions.td b/include/circt/Dialect/SV/SVExpressions.td
index 25495ebfc49a..34e2b398ce63 100644
--- a/include/circt/Dialect/SV/SVExpressions.td
+++ b/include/circt/Dialect/SV/SVExpressions.td
@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 include "mlir/Interfaces/InferTypeOpInterface.td"
+include "circt/Dialect/HW/HWTypes.td"
 include "circt/Dialect/SV/SVTypes.td"
 
 def HWValueOrInOutType : AnyTypeOf<[HWValueType, InOutType]>;
@@ -196,7 +197,7 @@ def ConstantStrOp : SVOp<"constantStr", [Pure]> {
     }];
 
   let arguments = (ins StrAttr:$str);
-  let results = (outs StringType:$result);
+  let results = (outs HWStringType:$result);
   let assemblyFormat = " $str attr-dict";
 }
 
diff --git a/include/circt/Dialect/SV/SVTypes.td b/include/circt/Dialect/SV/SVTypes.td
index b5ba10d2b49a..4a48eb4865b7 100644
--- a/include/circt/Dialect/SV/SVTypes.td
+++ b/include/circt/Dialect/SV/SVTypes.td
@@ -20,13 +20,6 @@ include "circt/Dialect/SV/SVDialect.td"
 // includable for other dialects, without polluting their output with SV types.
 class SVType<string name> : TypeDef<SVDialect, name> { }
 
-def StringType : SVType<"String"> {
-  let summary = "SystemVerilog string type";
-  let description = "Defines the string type in verilog";
-
-  let mnemonic = "string";
-}
-
 //===----------------------------------------------------------------------===//
 // InOut type and related helpers.
 //===----------------------------------------------------------------------===//
diff --git a/test/Conversion/ExportVerilog/sv-dialect.mlir b/test/Conversion/ExportVerilog/sv-dialect.mlir
index c9998d502d69..aaef29055578 100644
--- a/test/Conversion/ExportVerilog/sv-dialect.mlir
+++ b/test/Conversion/ExportVerilog/sv-dialect.mlir
@@ -1691,12 +1691,12 @@ hw.module @intrinsic(%clk: i1) -> (io1: i1, io2: i1, io3: i1, io4: i5) {
   // CHECK: assign io1 = clk === 1'bx
 
   %1 = sv.constantStr "foo"
-  %2 = sv.system "test$plusargs"(%1) : (!sv.string) -> i1
+  %2 = sv.system "test$plusargs"(%1) : (!hw.string) -> i1
   // CHECK: assign io2 = $test$plusargs("foo")
 
   %_pargs = sv.wire  : !hw.inout<i5>
   %3 = sv.read_inout %_pargs : !hw.inout<i5>
-  %4 = sv.system "value$plusargs"(%1, %_pargs) : (!sv.string, !hw.inout<i5>) -> i1
+  %4 = sv.system "value$plusargs"(%1, %_pargs) : (!hw.string, !hw.inout<i5>) -> i1
   // CHECK: assign io3 = $value$plusargs("foo", [[tmp]])
   // CHECK: assign io4 = [[tmp]]