From add3811f46f4eb38cacd30ca7817160868da3e00 Mon Sep 17 00:00:00 2001
From: Geza Lore <gezalore@gmail.com>
Date: Sat, 10 Jul 2021 12:03:51 +0100
Subject: [PATCH] Internals: Fix debug prints racing with option parsing.

debug() declared by VL_DEGUB_FUNC used to cache the result of the debug
level lookup (which depends on options) in a static. This meant that if
the debug() function was called before option parsing, the default debug
level of 0 would be used for the rest of the program, even if a --debug
option was given. Fixed by not caching the debug level until after
option parsing is complete.
---
 src/V3Error.h     | 6 +++++-
 src/V3Options.cpp | 3 +++
 src/V3Options.h   | 3 +++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/V3Error.h b/src/V3Error.h
index 870893c8e..cac812106 100644
--- a/src/V3Error.h
+++ b/src/V3Error.h
@@ -417,7 +417,11 @@ inline void v3errorEndFatal(std::ostringstream& sstr) {
 #define VL_DEBUG_FUNC \
     static int debug() { \
         static int level = -1; \
-        if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__); \
+        if (VL_UNLIKELY(level < 0)) { \
+            const int debugSrcLevel = v3Global.opt.debugSrcLevel(__FILE__); \
+            if (!v3Global.opt.available()) return debugSrcLevel; \
+            level = debugSrcLevel; \
+        } \
         return level; \
     }
 
diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index f5e141701..8e52d8761 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -791,6 +791,9 @@ void V3Options::notify() {
     if (coverage() && savable()) {
         cmdfl->v3error("--coverage and --savable not supported together");
     }
+
+    // Mark options as available
+    m_available = true;
 }
 
 //######################################################################
diff --git a/src/V3Options.h b/src/V3Options.h
index 3668fe605..6d42ccabe 100644
--- a/src/V3Options.h
+++ b/src/V3Options.h
@@ -361,6 +361,8 @@ private:
     bool        m_oTable;       // main switch: -Oa: lookup table creation
     // clang-format on
 
+    bool m_available = false;  // Set to true at the end of option parsing
+
 private:
     // METHODS
     void addArg(const string& arg);
@@ -402,6 +404,7 @@ public:
     void addVFile(const string& filename);
     void addForceInc(const string& filename);
     void notify();
+    bool available() const { return m_available; }
 
     // ACCESSORS (options)
     bool preprocOnly() const { return m_preprocOnly; }