Corrected handling of nested typedefs of struct/union

This also corrects shadowing of constants in struct/union types.

frontends/ast/simplify.cc

@@ -1380,6 +1380,60 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		break;
 
 	case AST_STRUCT_ITEM:
+		if (is_custom_type) {
+			log_assert(children.size() == 1);
+			log_assert(children[0]->type == AST_WIRETYPE);
+			auto type_name = children[0]->str;
+			if (!current_scope.count(type_name)) {
+				log_file_error(filename, location.first_line, "Unknown identifier `%s' used as type name\n", type_name.c_str());
+			}
+			AstNode *resolved_type_node = current_scope.at(type_name);
+			if (resolved_type_node->type != AST_TYPEDEF)
+				log_file_error(filename, location.first_line, "`%s' does not name a type\n", type_name.c_str());
+			log_assert(resolved_type_node->children.size() == 1);
+			AstNode *template_node = resolved_type_node->children[0];
+
+			// Ensure typedef itself is fully simplified
+			while (template_node->simplify(const_fold, at_zero, in_lvalue, stage, width_hint, sign_hint, in_param)) {};
+
+			// Remove type reference
+			delete children[0];
+			children.pop_back();
+
+			switch (template_node->type) {
+			case AST_WIRE:
+				type = AST_STRUCT_ITEM;
+				break;
+			case AST_STRUCT:
+			case AST_UNION:
+				type = template_node->type;
+				break;
+			default:
+				log_file_error(filename, location.first_line, "Invalid type for struct member: %s", type2str(template_node->type).c_str());
+			}
+
+			is_reg = template_node->is_reg;
+			is_logic = template_node->is_logic;
+			is_signed = template_node->is_signed;
+			is_string = template_node->is_string;
+			is_custom_type = template_node->is_custom_type;
+
+			range_valid = template_node->range_valid;
+			range_swapped = template_node->range_swapped;
+			range_left = template_node->range_left;
+			range_right = template_node->range_right;
+
+			attributes[ID::wiretype] = mkconst_str(resolved_type_node->str);
+
+			// Copy clones of children from template
+			for (auto template_child : template_node->children) {
+				children.push_back(template_child->clone());
+			}
+
+			did_something = true;
+
+		}
+		log_assert(!is_custom_type);
 		break;
 
 	case AST_ENUM:
@@ -1793,8 +1847,8 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			// Ensure typedef itself is fully simplified
 			while (template_node->simplify(const_fold, at_zero, in_lvalue, stage, width_hint, sign_hint, in_param)) {};
 
-			if (template_node->type == AST_STRUCT || template_node->type == AST_UNION) {
-				// replace with wire representing the packed structure
+			if (!str.empty() && str[0] == '\\' && (template_node->type == AST_STRUCT || template_node->type == AST_UNION)) {
+				// replace instance with wire representing the packed structure
 				newNode = make_packed_struct(template_node, str, attributes);
 				newNode->attributes[ID::wiretype] = mkconst_str(resolved_type_node->str);
 				// add original input/output attribute to resolved wire

frontends/verilog/verilog_parser.y

@@ -171,36 +171,6 @@ static bool isInLocalScope(const std::string *name)
 	return (user_types.count(*name) > 0);
 }
 
-static AstNode *getTypeDefinitionNode(std::string type_name)
-{
-	// check package types
-	if (type_name.find("::") != std::string::npos && pkg_user_types.count(type_name) > 0) {
-		auto typedef_node = pkg_user_types[type_name];
-		log_assert(typedef_node->type == AST_TYPEDEF);
-		return typedef_node->children[0];
-	}
-
-	// check current scope then outer scopes for a name
-	for (auto it = user_type_stack.rbegin(); it != user_type_stack.rend(); ++it) {
-		if (it->count(type_name) > 0) {
-			// return the definition nodes from the typedef statement
-			auto typedef_node = (*it)[type_name];
-			log_assert(typedef_node->type == AST_TYPEDEF);
-			return typedef_node->children[0];
-		}
-	}
-
-	// The lexer recognized the name as a TOK_USER_TYPE, but now we can't find it anymore?
-	log_error("typedef for user type `%s' not found", type_name.c_str());
-}
-
-static AstNode *copyTypeDefinition(std::string type_name)
-{
-	// return a copy of the template from a typedef definition
-	auto typedef_node = getTypeDefinitionNode(type_name);
-	return typedef_node->clone();
-}
-
 static AstNode *makeRange(int msb = 31, int lsb = 0, bool isSigned = true)
 {
 	auto range = new AstNode(AST_RANGE);
@@ -1633,10 +1603,7 @@ param_implicit_type: param_signed param_range;
 param_type:
 	param_integer_type | param_real | param_range_type | param_implicit_type |
 	hierarchical_type_id {
-		astbuf1->is_custom_type = true;
-		astbuf1->children.push_back(new AstNode(AST_WIRETYPE));
-		astbuf1->children.back()->str = *$1;
-		delete $1;
+		addWiretypeNode($1, astbuf1);
 	};
 
 param_decl:
@@ -1865,21 +1832,7 @@ struct_member_type: { astbuf1 = new AstNode(AST_STRUCT_ITEM); } member_type_toke
 member_type_token:
 	  member_type 
 	| hierarchical_type_id {
-			// use a clone of the typedef definition nodes
-			auto template_node = copyTypeDefinition(*$1);
-			delete $1;
-			switch (template_node->type) {
-			case AST_WIRE:
-				template_node->type = AST_STRUCT_ITEM;
-				break;
-			case AST_STRUCT:
-			case AST_UNION:
-				break;
-			default:
-				frontend_verilog_yyerror("Invalid type for struct member: %s", type2str(template_node->type).c_str());
-			}
-			delete astbuf1;
-			astbuf1 = template_node;
+			addWiretypeNode($1, astbuf1);
 		}
 	| {
 		delete astbuf1;

tests/svtypes/typedef_scopes.sv

@@ -17,6 +17,12 @@ module top;
 	always @(*) assert(inner_i1 == 4'hA);
 	always @(*) assert(inner_enum1 == 3'h3);
 
+	// adapted from tests/verilog/typedef_const_shadow.sv
+	localparam W = 5;
+	typedef logic [W-1:0] T;
+	T x; // width 5
+	always @(*) assert($bits(x) == 5);
+
 	if (1) begin: genblock
 		// type declarations in child scopes shadow their parents
 		typedef logic [7:0] inner_type;
@@ -34,6 +40,20 @@ module top;
 		} mystruct_t;
 		mystruct_t mystruct;
 		always @(*) assert($bits(mystruct) == 4);
+
+		// adapted from tests/verilog/typedef_const_shadow.sv
+		localparam W = 10;
+		typedef T U;
+		typedef logic [W-1:0] V;
+		struct packed {
+			logic [W-1:0] x; // width 10
+			U y; // width 5
+			V z; // width 10
+		} shadow;
+		// This currently only works as long as long as shadow is not typedef'ed
+		always @(*) assert($bits(shadow.x) == 10);
+		always @(*) assert($bits(shadow.y) == 5);
+		always @(*) assert($bits(shadow.z) == 10);
 	end
 
 	inner_type inner_i2 = 8'h42;

tests/svtypes/typedef_struct.sv

@@ -19,8 +19,10 @@ module top;
 		p::p_t		ps;
 	} s_t;
 
+	typedef s_t s1_t;
+
 	s_t s;
-	s_t s1;
+	s1_t s1;
 
 	p::p_t ps;