Fix access to whole sub-structs (#3086)

* Add support for accessing whole struct
* Update tests

Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com>

2 files changed, 18 insertions, 6 deletions

diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index 4c25287ad..020b4e5e8 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -877,7 +877,7 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun
 			this_width = id_ast->children[0]->range_left - id_ast->children[0]->range_right + 1;
 			if (children.size() > 1)
 				range = children[1];
-		} else if (id_ast->type == AST_STRUCT_ITEM) {
+		} else if (id_ast->type == AST_STRUCT_ITEM || id_ast->type == AST_STRUCT) {
 			AstNode *tmp_range = make_struct_member_range(this, id_ast);
 			this_width = tmp_range->range_left - tmp_range->range_right + 1;
 			delete tmp_range;
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 000877612..565025d3a 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -307,6 +307,10 @@ static int size_packed_struct(AstNode *snode, int base_offset)
 		if (node->type == AST_STRUCT || node->type == AST_UNION) {
 			// embedded struct or union
 			width = size_packed_struct(node, base_offset + offset);
+			// set range of struct
+			node->range_right = base_offset + offset;
+			node->range_left = base_offset + offset + width - 1;
+			node->range_valid = true;
 		}
 		else {
 			log_assert(node->type == AST_STRUCT_ITEM);
@@ -493,14 +497,12 @@ static void add_members_to_scope(AstNode *snode, std::string name)
 	// in case later referenced in assignments
 	log_assert(snode->type==AST_STRUCT || snode->type==AST_UNION);
 	for (auto *node : snode->children) {
+		auto member_name = name + "." + node->str;
+		current_scope[member_name] = node;
 		if (node->type != AST_STRUCT_ITEM) {
 			// embedded struct or union
 			add_members_to_scope(node, name + "." + node->str);
 		}
-		else {
-			auto member_name = name + "." + node->str;
-			current_scope[member_name] = node;
-		}
 	}
 }
 
@@ -1341,6 +1343,16 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
 	case AST_PARAMETER:
 	case AST_LOCALPARAM:
+		// if parameter is implicit type which is the typename of a struct or union,
+		// save information about struct in wiretype attribute
+		if (children[0]->type == AST_IDENTIFIER && current_scope.count(children[0]->str) > 0) {
+			auto item_node = current_scope[children[0]->str];
+			if (item_node->type == AST_STRUCT || item_node->type == AST_UNION) {
+				attributes[ID::wiretype] = item_node->clone();
+				size_packed_struct(attributes[ID::wiretype], 0);
+				add_members_to_scope(attributes[ID::wiretype], str);
+			}
+		}
 		while (!children[0]->basic_prep && children[0]->simplify(false, false, false, stage, -1, false, true) == true)
 			did_something = true;
 		children[0]->detectSignWidth(width_hint, sign_hint);
@@ -2018,7 +2030,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		if (name_has_dot(str, sname)) {
 			if (current_scope.count(str) > 0) {
 				auto item_node = current_scope[str];
-				if (item_node->type == AST_STRUCT_ITEM) {
+				if (item_node->type == AST_STRUCT_ITEM || item_node->type == AST_STRUCT) {
 					// structure member, rewrite this node to reference the packed struct wire
 					auto range = make_struct_member_range(this, item_node);
 					newNode = new AstNode(AST_IDENTIFIER, range);