[DSLX Fuzz testing] Add AttributeKind::kFuzzDomain to support #[fuzz_domain("DomainName")] attributes on structs.

xls/common/attribute_data.cc

@@ -40,6 +40,8 @@ std::string AttributeKindToString(AttributeKind kind) {
       return "channel_strictness";
     case AttributeKind::kFuzzTest:
       return "fuzz_test";
+    case AttributeKind::kFuzzDomain:
+      return "fuzz_domain";
   }
 }
 

xls/common/attribute_data.h

@@ -34,6 +34,7 @@ enum class AttributeKind : uint8_t {
   kQuickcheck,
   kChannelStrictness,
   kFuzzTest,
+  kFuzzDomain,
 };
 
 // Converts an AttributeKind to a string, e.g., "fuzz_test"

xls/dslx/frontend/ast.h

@@ -3417,9 +3417,22 @@ class StructDef : public StructDefBase {
     return extern_type_name_;
   }
 
+  void set_is_domain_struct(bool v) { is_domain_struct_ = v; }
+  bool is_domain_struct() const { return is_domain_struct_; }
+
+  void set_is_populated(bool v) { is_populated_ = v; }
+  bool is_populated() const { return is_populated_; }
+
+  void set_original_struct(StructDef* s) { original_struct_ = s; }
+  StructDef* original_struct() const { return original_struct_; }
+
  private:
   // The external verilog type name
   std::optional<std::string> extern_type_name_;
+
+  bool is_domain_struct_ = false;
+  bool is_populated_ = false;
+  StructDef* original_struct_ = nullptr;
 };
 
 // Represents a proc declared with struct-like syntax, with the functions in an

xls/dslx/frontend/parser.cc

@@ -22,6 +22,7 @@
 #include <optional>
 #include <string>
 #include <string_view>
+#include <type_traits>
 #include <utility>
 #include <variant>
 #include <vector>
@@ -225,6 +226,7 @@ absl::StatusOr<AttributeKind> ParseAttributeKind(Token token,
       {"test_proc", AttributeKind::kTestProc},
       {"quickcheck", AttributeKind::kQuickcheck},
       {"fuzz_test", AttributeKind::kFuzzTest},
+      {"fuzz_domain", AttributeKind::kFuzzDomain},
       {"channel_strictness", AttributeKind::kChannelStrictness}};
 
   const auto it = map->find(token.GetStringValue());
@@ -605,7 +607,7 @@ absl::StatusOr<std::unique_ptr<Module>> Parser::ParseModule(
             TypeAlias * type_alias,
             ParseTypeAlias(*module_member_start_pos, is_public, *bindings));
         XLS_RETURN_IF_ERROR(
-            ApplyTypeAttributes(type_alias, pending_attributes));
+            ApplyTypeAttributes(type_alias, pending_attributes, *bindings));
         XLS_RETURN_IF_ERROR(module_->AddTop(type_alias, make_collision_error));
         break;
       }
@@ -614,15 +616,16 @@ absl::StatusOr<std::unique_ptr<Module>> Parser::ParseModule(
             StructDef * struct_def,
             ParseStruct(*module_member_start_pos, is_public, *bindings));
         XLS_RETURN_IF_ERROR(
-            ApplyTypeAttributes(struct_def, pending_attributes));
+            ApplyTypeAttributes(struct_def, pending_attributes, *bindings));
         XLS_RETURN_IF_ERROR(module_->AddTop(struct_def, make_collision_error));
         break;
       }
       case Keyword::kEnum: {
         XLS_ASSIGN_OR_RETURN(
             EnumDef * enum_def,
             ParseEnumDef(*module_member_start_pos, is_public, *bindings));
-        XLS_RETURN_IF_ERROR(ApplyTypeAttributes(enum_def, pending_attributes));
+        XLS_RETURN_IF_ERROR(
+            ApplyTypeAttributes(enum_def, pending_attributes, *bindings));
         XLS_RETURN_IF_ERROR(module_->AddTop(enum_def, make_collision_error));
         break;
       }
@@ -949,6 +952,7 @@ absl::Status Parser::UnsupportedAttributeError(const Attribute& attribute) {
   Span span = *attribute.GetSpan();
   switch (attribute.attribute_kind()) {
     case AttributeKind::kDerive:
+    case AttributeKind::kFuzzDomain:
       return ParseErrorStatus(
           span,
           absl::StrCat(attribute.ToString(), " is only valid on a struct."));
@@ -1143,7 +1147,8 @@ absl::StatusOr<XlsTuple*> Parser::ParseFuzzTestDomains(
 
 template <typename T>
 absl::Status Parser::ApplyTypeAttributes(T* node,
-                                         std::vector<Attribute*> attributes) {
+                                         std::vector<Attribute*> attributes,
+                                         Bindings& bindings) {
   for (Attribute* next : attributes) {
     switch (next->attribute_kind()) {
       case AttributeKind::kDerive: {
@@ -1180,6 +1185,45 @@ absl::Status Parser::ApplyTypeAttributes(T* node,
         break;
       }
 
+      case AttributeKind::kFuzzDomain: {
+        if constexpr (!std::is_same_v<T, StructDef>) {
+          return UnsupportedAttributeError(*next);
+        } else {
+          if (next->args().size() != 1 ||
+              !std::holds_alternative<AttributeData::StringLiteralArgument>(
+                  next->args()[0])) {
+            return ParseErrorStatus(
+                *next->GetSpan(),
+                "fuzz_domain attribute requires a string argument.");
+          }
+          std::string domain_name =
+              std::get<AttributeData::StringLiteralArgument>(next->args()[0])
+                  .text;
+
+          StructDef* struct_def = node;
+          Span span = *next->GetSpan();
+          NameDef* domain_name_def =
+              module_->Make<NameDef>(span, domain_name, /*definer=*/nullptr);
+          std::vector<ParametricBinding*> parametric_bindings;
+          std::vector<StructMemberNode*> members;
+          StructDef* domain_struct = module_->Make<StructDef>(
+              span, domain_name_def, std::move(parametric_bindings),
+              std::move(members), struct_def->is_public());
+          domain_name_def->set_definer(domain_struct);
+
+          domain_struct->set_is_domain_struct(true);
+          domain_struct->set_original_struct(struct_def);
+
+          bindings.Add(domain_name, domain_struct);
+
+          auto make_collision_error =
+              absl::bind_front(&MakeModuleTopCollisionError, file_table());
+          XLS_RETURN_IF_ERROR(
+              module_->AddTop(domain_struct, make_collision_error));
+        }
+        break;
+      }
+
       default:
         return UnsupportedAttributeError(*next);
     }

xls/dslx/frontend/parser.h

@@ -674,7 +674,8 @@ class Parser : public TokenParser {
       const std::vector<Attribute*>& attributes);
 
   template <typename T>
-  absl::Status ApplyTypeAttributes(T* node, std::vector<Attribute*> attributes);
+  absl::Status ApplyTypeAttributes(T* node, std::vector<Attribute*> attributes,
+                                   Bindings& bindings);
 
   absl::StatusOr<QuickCheckTestCases> GetQuickCheckTestCases(
       const Attribute& attribute);

xls/dslx/frontend/parser_test.cc

@@ -4964,4 +4964,27 @@ fn f(x: u32, y: u8) {}
   EXPECT_TRUE(second_member_tuple->members().empty());
 }
 
+TEST_F(ParserTest, FuzzDomainAttribute) {
+  std::string_view program = R"(
+#[fuzz_domain("MyDomain")]
+struct MyStruct {
+    x: u32,
+}
+)";
+  auto module = ExpectParsesSuccessfully(program);
+  ASSERT_NE(module, nullptr);
+
+  // Verify MyStruct exists.
+  XLS_ASSERT_OK_AND_ASSIGN(StructDef * my_struct,
+                           module->GetMemberOrError<StructDef>("MyStruct"));
+  EXPECT_FALSE(my_struct->is_domain_struct());
+
+  // Verify MyDomain exists and is linked.
+  XLS_ASSERT_OK_AND_ASSIGN(StructDef * my_domain,
+                           module->GetMemberOrError<StructDef>("MyDomain"));
+  EXPECT_TRUE(my_domain->is_domain_struct());
+  EXPECT_FALSE(my_domain->is_populated());
+  EXPECT_EQ(my_domain->original_struct(), my_struct);
+}
+
 }  // namespace xls::dslx