From 96ec9acf84d6eba753d6a2482b78acbf293544a5 Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Sun, 9 Aug 2020 09:31:57 -0600
Subject: [PATCH] Allow %0s $display format specifier

---
 frontends/ast/simplify.cc    | 2 +-
 tests/simple/string_format.v | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 tests/simple/string_format.v

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 66f22e113..3a652d6cd 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -89,7 +89,7 @@ std::string AstNode::process_format_str(const std::string &sformat, int next_arg
 				case 'S':
 				case 'd':
 				case 'D':
-					if (got_len)
+					if (got_len && len_value != 0)
 						goto unsupported_format;
 					YS_FALLTHROUGH
 				case 'x':
diff --git a/tests/simple/string_format.v b/tests/simple/string_format.v
new file mode 100644
index 000000000..ce45ca1e9
--- /dev/null
+++ b/tests/simple/string_format.v
@@ -0,0 +1,7 @@
+module top;
+	parameter STR = "something interesting";
+	initial begin
+		$display("A: %s", STR);
+		$display("B: %0s", STR);
+	end
+endmodule
-- 
2.30.2