From bbb3d5379b90c030e50abf7f8f49f4e7ae9fe20b Mon Sep 17 00:00:00 2001
From: Nikolaj Bjorner <nbjorner@microsoft.com>
Date: Wed, 28 May 2025 17:10:23 +0100
Subject: [PATCH] initialize tag class circular linked list

---
 src/util/trace.cpp    | 31 +++++++++++++++++++++++++++++++
 src/util/trace_tags.h | 17 +++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/src/util/trace.cpp b/src/util/trace.cpp
index bb4812e00..8c379ca6b 100644
--- a/src/util/trace.cpp
+++ b/src/util/trace.cpp
@@ -57,6 +57,37 @@ void finalize_trace() {
     g_enabled_trace_tags = nullptr;
 }
 
+const TraceTag* get_tag_classes() {
+   static bool tag_class_init = false; // ignore thread safety assuming TRACE is already under a lock.
+   if (!tag_class_init) {
+       // Arrays to track first and last tag in each class
+       TraceTag first[static_cast<unsigned>(TraceTag::Count)];
+       TraceTag last[static_cast<unsigned>(TraceTag::Count)];
+       for (unsigned i = 0; i < static_cast<unsigned>(TraceTag::Count); ++i)
+           first[i] = last[i] = TraceTag::Count;
+
+       // Link tags in each class
+       for (unsigned i = 0; i < static_cast<unsigned>(TraceTag::Count); ++i) {
+           TraceTag tag = static_cast<TraceTag>(i);
+           TraceTag tag_class = get_trace_tag_class(tag);
+           unsigned cls = static_cast<unsigned>(tag_class);
+           if (first[cls] == TraceTag::Count) 
+               first[cls] = tag;           
+           else 
+               tag_classes[static_cast<unsigned>(last[cls])] = tag;           
+           last[cls] = tag;
+       }
+       // Close the circular list for each class
+       for (unsigned cls = 0; cls < static_cast<unsigned>(TraceTag::Count); ++cls) 
+           if (last[cls] != TraceTag::Count && first[cls] != TraceTag::Count) 
+               tag_classes[static_cast<unsigned>(last[cls])] = first[cls];
+                 
+       tag_class_init = true;
+   }
+   return tag_classes;
+}
+
+
 void enable_trace(const char * tag) {
     get_enabled_trace_tags().insert(tag);
     
diff --git a/src/util/trace_tags.h b/src/util/trace_tags.h
index 73c9c0f1f..cef20d3cd 100644
--- a/src/util/trace_tags.h
+++ b/src/util/trace_tags.h
@@ -29,6 +29,15 @@ inline const char* get_trace_tag_doc(TraceTag tag) {
     }
 }
 
+inline TraceTag get_trace_tag_class(TraceTag tag) {
+    switch (tag) {
+#define X(tag, tag_class, desc) case TraceTag::tag: return TraceTag::tag_class;
+#include "util/trace_tags.def"
+#undef X
+    default: return TraceTag::Count;
+    }
+}
+
 // Return the number of TraceTags
 inline constexpr int trace_tag_count() {
     return static_cast<int>(TraceTag::Count);
@@ -44,6 +53,14 @@ inline constexpr int count_tags_in_class(TraceTag cls) {
     return count;
 }
 
+
+static TraceTag tag_classes[] = {
+#define X(tag, tc, desc) TraceTag::tag,
+#include "util/trace_tags.def"
+#undef  X
+};
+
+
 // TODO(#7663): Implement tag_class activation of all associated tags
 // TODO: Need to consider implementation approach and memory management
 // Return all tags that belong to the given class