From 023b2edd48f0f289364a09cc60c53c048e66373b Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Mon, 13 Apr 2026 21:07:03 -0400
Subject: [PATCH] Add newline on alarm timeouts to help error parsers

---
 src/V3EmitCMain.cpp                           | 3 +++
 test_regress/t/t_flag_runtime_timeout_bad.out | 1 +
 2 files changed, 4 insertions(+)

diff --git a/src/V3EmitCMain.cpp b/src/V3EmitCMain.cpp
index d4df97d08..136eb7e4c 100644
--- a/src/V3EmitCMain.cpp
+++ b/src/V3EmitCMain.cpp
@@ -73,6 +73,9 @@ private:
 
         if (v3Global.opt.debugRuntimeTimeout()) {
             puts("void alarmHandler(int signum) {\n");
+            // Add newline so %Error is at beginning-of-line, as might get the alarm
+            // when in the middle of some other print with no newline
+            puts("    VL_PRINTF_MT(\"\\n\");\n");
             puts("    VL_FATAL_MT(\"\", 0, \"\", \"Alarm signal received,"s
                  + " '--debug-runtime-timeout "s
                  + std::to_string(v3Global.opt.debugRuntimeTimeout()) + "' exceeded\\n\");\n");
diff --git a/test_regress/t/t_flag_runtime_timeout_bad.out b/test_regress/t/t_flag_runtime_timeout_bad.out
index 2566e4d39..edbddf692 100644
--- a/test_regress/t/t_flag_runtime_timeout_bad.out
+++ b/test_regress/t/t_flag_runtime_timeout_bad.out
@@ -1,4 +1,5 @@
 Sleeping....
+
 %Error: Alarm signal received, '--debug-runtime-timeout 1' exceeded
 
 Aborting...