From 220cb1f7bbf6405117b953526c50a21a5ef5788f Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Thu, 18 Feb 2021 12:04:02 -0500
Subject: [PATCH] verilog: error on macro invocations with missing argument
 lists

This would previously complain about an undefined internal macro if the
unapplied macro had not already been used. If it had, it would
incorrectly use the arguments from the previous invocation.
---
 frontends/verilog/preproc.cc             | 11 ++++++++++-
 tests/verilog/macro_unapplied.ys         | 17 +++++++++++++++++
 tests/verilog/macro_unapplied_newline.ys |  5 +++++
 3 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 tests/verilog/macro_unapplied.ys
 create mode 100644 tests/verilog/macro_unapplied_newline.ys

diff --git a/frontends/verilog/preproc.cc b/frontends/verilog/preproc.cc
index c451c4c20..de707593f 100644
--- a/frontends/verilog/preproc.cc
+++ b/frontends/verilog/preproc.cc
@@ -477,7 +477,16 @@ static bool try_expand_macro(define_map_t &defines, std::string &tok)
 	std::string name = tok.substr(1);
 	std::string skipped_spaces = skip_spaces();
 	tok = next_token(false);
-	if (tok == "(" && body->has_args) {
+	if (body->has_args) {
+		if (tok != "(") {
+			if (tok.size() == 1 && iscntrl(tok[0])) {
+				char buf[5];
+				snprintf(buf, sizeof(buf), "\\x%02x", tok[0]);
+				tok = buf;
+			}
+			log_error("Expected to find '(' to begin macro arguments for '%s', but instead found '%s'\n",
+				name.c_str(), tok.c_str());
+		}
 		std::vector<std::string> args;
 		bool done = false;
 		while (!done) {
diff --git a/tests/verilog/macro_unapplied.ys b/tests/verilog/macro_unapplied.ys
new file mode 100644
index 000000000..81eb10b8b
--- /dev/null
+++ b/tests/verilog/macro_unapplied.ys
@@ -0,0 +1,17 @@
+logger -expect-no-warnings
+read_verilog -sv <<EOT
+`define MACRO(a = 1, b = 2) initial $display("MACRO(a = %d, b = %d)", a, b)
+module top;
+    `MACRO();
+endmodule
+EOT
+
+design -reset
+
+logger -expect error "Expected to find '\(' to begin macro arguments for 'MACRO', but instead found ';'" 1
+read_verilog -sv <<EOT
+`define MACRO(a = 1, b = 2) initial $display("MACRO(a = %d, b = %d)", a, b)
+module top;
+    `MACRO;
+endmodule
+EOT
diff --git a/tests/verilog/macro_unapplied_newline.ys b/tests/verilog/macro_unapplied_newline.ys
new file mode 100644
index 000000000..a3f88d5b4
--- /dev/null
+++ b/tests/verilog/macro_unapplied_newline.ys
@@ -0,0 +1,5 @@
+logger -expect error "Expected to find '\(' to begin macro arguments for 'foo', but instead found '\\x0a'" 1
+read_verilog -sv <<EOT
+`define foo(a=1) (a)
+`foo
+EOT
-- 
2.30.2