[FIRRTL] Add fields to domains

Extend domains to allow for them to contain fields.  These fields provide
a schema of information that all domains of certain kind must have.  This
models information that a user must provide for an input domain or is
provided for an output domain.

Opt for a "struct-like" representation as opposed to using input/output
ports like FIRRTL classes.  That said, these are intended to be lowered to
classes in a future patch.

Signed-off-by: Schuyler Eldridge <[email protected]>

Author: seldridge

include/circt/Dialect/FIRRTL/FIRRTLAttributes.td

@@ -209,4 +209,19 @@ def InternalPathArrayAttr
 
 def LayerArrayAttr : TypedArrayRefAttrBase<SymbolRefAttr, "an array of layers">;
 
+def DomainFieldAttr : AttrDef<FIRRTLDialect, "DomainField"> {
+  let mnemonic = "domain.field";
+  let summary = "A single field of a domain";
+  let parameters = (
+    ins "::mlir::StringAttr":$name,
+        "::mlir::TypeAttr":$type
+  );
+  let assemblyFormat = [{
+    `<` $name `,` $type `>`
+  }];
+}
+
+def DomainFieldArrayAttr :
+  TypedArrayAttrBase<DomainFieldAttr, "an array of domain fields">;
+
 #endif // CIRCT_DIALECT_FIRRTL_FIRRTLATTRIBUTES_TD

include/circt/Dialect/FIRRTL/FIRRTLStructure.td

@@ -614,11 +614,14 @@ def DomainOp : FIRRTLOp<"domain", [
     circuit.  E.g., this can be used to declare a `ClockDomain` type when
     modeling clocks in FIRRTL Dialect.
   }];
-  let arguments = (ins SymbolNameAttr:$sym_name);
+  let arguments = (
+    ins SymbolNameAttr:$sym_name,
+        DefaultValuedAttr<DomainFieldArrayAttr, "{}">:$fields
+  );
   let results = (outs);
   let regions = (region SizedRegion<1>:$body);
   let assemblyFormat = [{
-    $sym_name attr-dict-with-keyword $body
+    $sym_name ( $fields^ )? attr-dict-with-keyword $body
   }];
 }
 

lib/Dialect/FIRRTL/Export/FIREmitter.cpp

@@ -644,6 +644,13 @@ void Emitter::emitDeclaration(DomainOp op) {
   startStatement();
   ps << "domain " << PPExtString(op.getSymName()) << " :";
   emitLocationAndNewLine(op);
+  ps.scopedBox(PP::bbox2, [&]() {
+    for (auto attr : op.getFields()) {
+      auto fieldAttr = cast<DomainFieldAttr>(attr);
+      ps << PP::newline << PPExtString(fieldAttr.getName()) << " : ";
+      emitType(fieldAttr.getType().getValue());
+    }
+  });
 }
 
 /// Emit a layer definition.

lib/Dialect/FIRRTL/Import/FIRParser.cpp

@@ -5751,8 +5751,25 @@ ParseResult FIRCircuitParser::parseDomain(CircuitOp circuit, unsigned indent) {
       info.parseOptionalInfo())
     return failure();
 
+  SmallVector<Attribute> fields;
+  while (true) {
+    auto nextIndent = getIndentation();
+    if (!nextIndent || *nextIndent <= indent)
+      break;
+
+    StringAttr fieldName;
+    PropertyType type;
+    if (parseId(fieldName, "field name") ||
+        parseToken(FIRToken::colon, "expected ':' after field name") ||
+        parsePropertyType(type, "field type") || info.parseOptionalInfo())
+      return failure();
+
+    fields.push_back(DomainFieldAttr::get(circuit.getContext(), fieldName,
+                                          TypeAttr::get(type)));
+  }
+
   auto builder = circuit.getBodyBuilder();
-  DomainOp::create(builder, info.getLoc(), name)
+  DomainOp::create(builder, info.getLoc(), name, builder.getArrayAttr(fields))
       ->getRegion(0)
       .push_back(new Block());
 

test/Dialect/FIRRTL/emit-basic.mlir

@@ -958,6 +958,16 @@ firrtl.circuit "Foo" {
   // CHECK-LABEL: domain ClockDomain :
   firrtl.domain @ClockDomain {}
 
+  // CHECK-LABEL: domain PowerDomain :
+  // CHECK-NEXT:    name : String
+  // CHECK-NEXT:    voltage : Integer
+  // CHECk-NEXT:    alwaysOn : Bool
+  firrtl.domain @PowerDomain [
+    #firrtl.domain.field<"name", !firrtl.string>,
+    #firrtl.domain.field<"voltage", !firrtl.integer>,
+    #firrtl.domain.field<"alwaysOn", !firrtl.bool>
+  ] {}
+
   // CHECK-LABEL: module Domains :
   firrtl.module @Domains(
     // CHECK-NEXT: input A : Domain of ClockDomain

test/Dialect/FIRRTL/parse-basic.fir

@@ -2195,9 +2195,19 @@ circuit NullaryCat:
 ;// -----
 FIRRTL version 5.1.0
 circuit Domains:
-  ; CHECK-LABEL: firrtl.domain @ClockDomain
+  ; CHECK-LABEL: firrtl.domain @ClockDomain {
   domain ClockDomain:
 
+  ; CHECK-LABEL: firrtl.domain @PowerDomain [
+  ; CHECK-SAME:    #firrtl.domain.field<"name", !firrtl.string>
+  ; CHECK-SAME:    #firrtl.domain.field<"voltage", !firrtl.integer>
+  ; CHECK-SAME:    #firrtl.domain.field<"alwaysOn", !firrtl.bool>
+  ; CHECK-SAME:  ] {
+  domain PowerDomain:
+    name : String
+    voltage : Integer
+    alwaysOn : Bool
+
   module Foo:
     input A: Domain of ClockDomain
     input a: UInt<1> domains [A]

test/Dialect/FIRRTL/round-trip.mlir

@@ -196,10 +196,21 @@ firrtl.module @Fprintf(
   firrtl.fprintf %clock, %a, "test%d.txt"(%a), "%x, %b"(%a, %reset) {name = "foo"} : !firrtl.clock, !firrtl.uint<1>, !firrtl.uint<1>, !firrtl.uint<1>, !firrtl.reset
 }
 
-// CHECK-LABEL: firrtl.domain @ClockDomain
+// CHECK-LABEL: firrtl.domain @ClockDomain {
 firrtl.domain @ClockDomain {
 }
 
+// CHECK-LABEL: firrtl.domain @PowerDomain [
+// CHECK-SAME:    #firrtl.domain.field<"name", !firrtl.string>
+// CHECK-SAME:    #firrtl.domain.field<"voltage", !firrtl.integer>
+// CHECK-SAME:    #firrtl.domain.field<"alwaysOn", !firrtl.bool>
+// CHECK-SAME:  ] {
+firrtl.domain @PowerDomain [
+  #firrtl.domain.field<"name", !firrtl.string>,
+  #firrtl.domain.field<"voltage", !firrtl.integer>,
+  #firrtl.domain.field<"alwaysOn", !firrtl.bool>
+] {}
+
 firrtl.module @DomainsSubmodule(
   in %A: !firrtl.domain of @ClockDomain,
   in %a: !firrtl.uint<1> domains [%A]