From 1a8188e1b4af8f35a53521be393fdec07cb1f04f Mon Sep 17 00:00:00 2001
From: Krzysztof Bieganski <kbieganski@antmicro.com>
Date: Thu, 6 Oct 2022 00:16:05 +0200
Subject: [PATCH] Fix linker errors in user-facing timing functions (#3657)

Before this change, a design verilated with `--timing` that does not
actually use timing features would be emitted with `eventsPending` and
`nextTimeSlot` declared in the top class. However, their definitions
would be missing, leading to linker errors during design compilation.
This patch makes Verilator always emit the definitions, which prevents
linker errors. Trying to use `nextTimeSlot` without delays in the design
will result in an error at runtime.
---
 src/V3EmitCModel.cpp | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/V3EmitCModel.cpp b/src/V3EmitCModel.cpp
index 0be57f9c9..f3425caff 100644
--- a/src/V3EmitCModel.cpp
+++ b/src/V3EmitCModel.cpp
@@ -439,22 +439,20 @@ class EmitCModel final : public EmitCFunc {
             puts("}\n");
         }
 
-        if (v3Global.usesTiming()) {
-            putSectionDelimiter("Events and timing");
-            if (auto* const delaySchedp = v3Global.rootp()->delaySchedulerp()) {
-                puts("bool " + topClassName() + "::eventsPending() { return !vlSymsp->TOP.");
-                puts(delaySchedp->nameProtect());
-                puts(".empty(); }\n\n");
-                puts("uint64_t " + topClassName() + "::nextTimeSlot() { return vlSymsp->TOP.");
-                puts(delaySchedp->nameProtect());
-                puts(".nextTimeSlot(); }\n");
-            } else {
-                puts("bool " + topClassName() + "::eventsPending() { return false; }\n\n");
-                puts("uint64_t " + topClassName() + "::nextTimeSlot() {\n");
-                puts("VL_FATAL_MT(__FILE__, __LINE__, \"\", \"%Error: No delays in the "
-                     "design\");\n");
-                puts("return 0;\n}\n");
-            }
+        putSectionDelimiter("Events and timing");
+        if (auto* const delaySchedp = v3Global.rootp()->delaySchedulerp()) {
+            puts("bool " + topClassName() + "::eventsPending() { return !vlSymsp->TOP.");
+            puts(delaySchedp->nameProtect());
+            puts(".empty(); }\n\n");
+            puts("uint64_t " + topClassName() + "::nextTimeSlot() { return vlSymsp->TOP.");
+            puts(delaySchedp->nameProtect());
+            puts(".nextTimeSlot(); }\n");
+        } else {
+            puts("bool " + topClassName() + "::eventsPending() { return false; }\n\n");
+            puts("uint64_t " + topClassName() + "::nextTimeSlot() {\n");
+            puts("VL_FATAL_MT(__FILE__, __LINE__, \"\", \"%Error: No delays in the "
+                 "design\");\n");
+            puts("return 0;\n}\n");
         }
 
         putSectionDelimiter("Utilities");