From ce74404890242d8a45bccb6ee2fefd302316efcf Mon Sep 17 00:00:00 2001
From: Jannis Harder <me@jix.one>
Date: Wed, 16 Apr 2025 19:12:01 +0200
Subject: [PATCH] liberty: Error on unclosed curly braces

This is an indication that the liberty file was truncated, which
shouldn't be silently ignored.
---
 passes/techmap/libparse.cc | 23 +++++++++++++++++++----
 passes/techmap/libparse.h  |  6 +++---
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/passes/techmap/libparse.cc b/passes/techmap/libparse.cc
index 97a94ece0..5594d5443 100644
--- a/passes/techmap/libparse.cc
+++ b/passes/techmap/libparse.cc
@@ -436,6 +436,9 @@ void LibertyParser::report_unexpected_token(int tok)
 		eReport += "'.";
 		error(eReport);
 		break;
+	case EOF:
+		error("Unexpected end of file");
+		break;
 	default:
 		eReport = "Unexpected token: ";
 		eReport += static_cast<char>(tok);
@@ -484,7 +487,7 @@ void LibertyParser::parse_vector_range(int tok)
 	}
 }
 
-LibertyAst *LibertyParser::parse()
+LibertyAst *LibertyParser::parse(bool top_level)
 {
 	std::string str;
 
@@ -498,7 +501,13 @@ LibertyAst *LibertyParser::parse()
 	while ((tok == 'n') || (tok == ';'))
 		tok = lexer(str);
 
-	if (tok == '}' || tok < 0)
+	if (tok == EOF) {
+		if (top_level)
+			return NULL;
+		report_unexpected_token(tok);
+	}
+
+	if (tok == '}')
 		return NULL;
 
 	if (tok != 'v') {
@@ -571,12 +580,18 @@ LibertyAst *LibertyParser::parse()
 		}
 
 		if (tok == '{') {
+			bool terminated = false;
 			while (1) {
-				LibertyAst *child = parse();
-				if (child == NULL)
+				LibertyAst *child = parse(false);
+				if (child == NULL) {
+					terminated = true;
 					break;
+				}
 				ast->children.push_back(child);
 			}
+			if (!terminated) {
+				report_unexpected_token(EOF);
+			}
 			break;
 		}
 
diff --git a/passes/techmap/libparse.h b/passes/techmap/libparse.h
index e52f91e77..61dc83867 100644
--- a/passes/techmap/libparse.h
+++ b/passes/techmap/libparse.h
@@ -165,7 +165,7 @@ namespace Yosys
 
 		void report_unexpected_token(int tok);
 		void parse_vector_range(int tok);
-		LibertyAst *parse();
+		LibertyAst *parse(bool top_level);
 		void error() const;
 		void error(const std::string &str) const;
 
@@ -174,7 +174,7 @@ namespace Yosys
 		const LibertyAst *ast = nullptr;
 
 		LibertyParser(std::istream &f) : f(f), line(1) {
-			shared_ast.reset(parse());
+			shared_ast.reset(parse(true));
 			ast = shared_ast.get();
 			if (!ast) {
 #ifdef FILTERLIB
@@ -190,7 +190,7 @@ namespace Yosys
 		LibertyParser(std::istream &f, const std::string &fname) : f(f), line(1) {
 			shared_ast = LibertyAstCache::instance.cached_ast(fname);
 			if (!shared_ast) {
-				shared_ast.reset(parse());
+				shared_ast.reset(parse(true));
 				LibertyAstCache::instance.parsed_ast(fname, shared_ast);
 			}
 			ast = shared_ast.get();