From 0a9ae154be0c66d422e97c9280fd55c07c111ffb Mon Sep 17 00:00:00 2001
From: Markus Krause <Krause.Markus@gmx.com>
Date: Sun, 11 Oct 2020 03:17:39 +0200
Subject: [PATCH] introduce define for FST tracing (#2592)

This is to allow C++ verilator toplevel to support
multiple modes of waveform tracing
VM_TRACE_FST can be used inside a #if VM_TRACE
section to switch between classic .vcd tracing and the
more compact .fst format supported by GTKWAVE
---
 docs/CONTRIBUTORS       | 1 +
 include/verilated.mk.in | 1 +
 src/V3EmitMk.cpp        | 4 ++++
 3 files changed, 6 insertions(+)

diff --git a/docs/CONTRIBUTORS b/docs/CONTRIBUTORS
index 18c6447e8..2442f3b2a 100644
--- a/docs/CONTRIBUTORS
+++ b/docs/CONTRIBUTORS
@@ -40,6 +40,7 @@ Lukasz Dalek
 Maarten De Braekeleer
 Maciej Sobkowski
 Marco Widmer
+Markus Krause
 Marshal Qiao
 Matthew Ballance
 Michael Killough
diff --git a/include/verilated.mk.in b/include/verilated.mk.in
index f08066a49..eb6b2b72c 100644
--- a/include/verilated.mk.in
+++ b/include/verilated.mk.in
@@ -54,6 +54,7 @@ VK_CPPFLAGS_ALWAYS += \
 		-DVM_COVERAGE=$(VM_COVERAGE) \
 		-DVM_SC=$(VM_SC) \
 		-DVM_TRACE=$(VM_TRACE) \
+		-DVM_TRACE_FST=$(VM_TRACE_FST) \
 		$(CFG_CXXFLAGS_NO_UNUSED) \
 
 ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
diff --git a/src/V3EmitMk.cpp b/src/V3EmitMk.cpp
index e0cfd151a..55312dbe3 100644
--- a/src/V3EmitMk.cpp
+++ b/src/V3EmitMk.cpp
@@ -65,6 +65,10 @@ public:
         of.puts("VM_TRACE = ");
         of.puts(v3Global.opt.trace() ? "1" : "0");
         of.puts("\n");
+        of.puts("# Tracing output mode in FST format?  0/1 (from --trace-fst)\n");
+        of.puts("VM_TRACE_FST = ");
+        of.puts(v3Global.opt.trace() && v3Global.opt.traceFormat().fst() ? "1" : "0");
+        of.puts("\n");
         of.puts("# Tracing threaded output mode?  0/1/N threads (from --trace-thread)\n");
         of.puts("VM_TRACE_THREADS = ");
         of.puts(cvtToStr(v3Global.opt.trueTraceThreads()));