From 4b1a8a3b667d133fc583ba40e20192f3f4e520da Mon Sep 17 00:00:00 2001
From: "Emil J. Tywoniak" <emil@tywoniak.eu>
Date: Fri, 11 Jul 2025 18:27:19 +0200
Subject: [PATCH] libparse: add LibertyExpression::str for testing

---
 passes/techmap/dfflibmap.cc |  1 +
 passes/techmap/libparse.cc  | 41 +++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/passes/techmap/dfflibmap.cc b/passes/techmap/dfflibmap.cc
index f0b0ef20b..ae9498a9c 100644
--- a/passes/techmap/dfflibmap.cc
+++ b/passes/techmap/dfflibmap.cc
@@ -117,6 +117,7 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
 	// the next_state variable isn't just a pin name; perhaps this is an enable?
 	auto helper = LibertyExpression::Lexer(expr);
 	auto tree = LibertyExpression::parse(helper);
+	log_debug("liberty expression:\n%s\n", tree.str().c_str());
 
 	if (tree.kind == LibertyExpression::Kind::EMPTY) {
 		if (!warned_cells.count(cell_name)) {
diff --git a/passes/techmap/libparse.cc b/passes/techmap/libparse.cc
index 85ed35ea1..0df7af347 100644
--- a/passes/techmap/libparse.cc
+++ b/passes/techmap/libparse.cc
@@ -306,6 +306,47 @@ bool LibertyExpression::eval(dict<std::string, bool>& values) {
 	}
 	return false;
 }
+
+std::string LibertyExpression::str(int indent)
+{
+	std::string prefix;
+	prefix = std::string(indent, ' ');
+	switch (kind) {
+		case AND:
+			prefix += "(and ";
+			break;
+		case OR:
+			prefix += "(or ";
+			break;
+		case NOT:
+			prefix += "(not ";
+			break;
+		case XOR:
+			prefix += "(xor ";
+			break;
+		case PIN:
+			prefix += "(pin \"" + name + "\"";
+			break;
+		case EMPTY:
+			prefix += "(";
+			break;
+		default:
+			log_assert(false);
+	}
+	size_t add_indent = prefix.length();
+	bool first = true;
+	for (auto child : children) {
+		if (!first) {
+			prefix += "\n" + child.str(indent + add_indent);
+		} else {
+			prefix += child.str(0);
+		}
+		first = false;
+	}
+	prefix += ")";
+	return prefix;
+}
+
 #endif
 
 int LibertyParser::lexer(std::string &str)