From 10ea2fa67e1b084749a2acc9d11a95dbb6953add Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Sat, 10 May 2025 17:24:13 +1200
Subject: [PATCH] ast.h: Move attribute check into set

There are a number of places that check for an existing attribute and delete it before assigning a new node to it.
Reduce code duplication by doing it as part of the `set_attribute()` method.
---
 frontends/ast/ast.cc      | 4 ----
 frontends/ast/ast.h       | 2 ++
 frontends/ast/simplify.cc | 6 ------
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 431f7b4f8..e2e83a225 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -1174,10 +1174,6 @@ static RTLIL::Module *process_module(RTLIL::Design *design, AstNode *ast, bool d
 				delete ast->attributes.at(ID::lib_whitebox);
 				ast->attributes.erase(ID::lib_whitebox);
 			} else {
-				if (ast->attributes.count(ID::whitebox)) {
-					delete ast->attributes.at(ID::whitebox);
-					ast->attributes.erase(ID::whitebox);
-				}
 				AstNode *n = ast->attributes.at(ID::lib_whitebox);
 				ast->set_attribute(ID::whitebox, n);
 				ast->attributes.erase(ID::lib_whitebox);
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 2c2d408ce..66417cda2 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -360,6 +360,8 @@ namespace AST
 
 		void set_attribute(RTLIL::IdString key, AstNode *node)
 		{
+			if (attributes.count(key))
+				delete attributes.at(key);
 			attributes[key] = node;
 			node->set_in_param_flag(true);
 		}
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 3411d6c03..73bf3245a 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1110,8 +1110,6 @@ bool AstNode::simplify(bool const_fold, int stage, int width_hint, bool sign_hin
 				if (node->children.size() == 1 && node->children[0]->type == AST_RANGE) {
 					for (auto c : node->children[0]->children) {
 						if (!c->is_simple_const_expr()) {
-							if (attributes.count(ID::dynports))
-								delete attributes.at(ID::dynports);
 							set_attribute(ID::dynports, AstNode::mkconst_int(1, true));
 						}
 					}
@@ -1159,8 +1157,6 @@ bool AstNode::simplify(bool const_fold, int stage, int width_hint, bool sign_hin
 					if (node->is_signed)
 						first_node->is_signed = true;
 					for (auto &it : node->attributes) {
-						if (first_node->attributes.count(it.first) > 0)
-							delete first_node->attributes[it.first];
 						first_node->set_attribute(it.first, it.second->clone());
 					}
 					children.erase(children.begin()+(i--));
@@ -1919,8 +1915,6 @@ bool AstNode::simplify(bool const_fold, int stage, int width_hint, bool sign_hin
 			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);
-				if (newNode->attributes.count(ID::wiretype))
-					delete newNode->attributes[ID::wiretype];
 				newNode->set_attribute(ID::wiretype, mkconst_str(resolved_type_node->str));
 				// add original input/output attribute to resolved wire
 				newNode->is_input = this->is_input;