From 1fd26a03b214739ba6781c2619ad4dca23709375 Mon Sep 17 00:00:00 2001
From: Zygo Blaxell <bees@furryterror.org>
Date: Wed, 2 Jun 2021 00:13:48 -0400
Subject: [PATCH] tracer: annotate both ends of the stack trace

Add a matching "--- BEGIN TRACE..." line to complement the "---  END
TRACE..." line.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
---
 src/bees.cc | 6 ++++++
 src/bees.h  | 1 +
 2 files changed, 7 insertions(+)

diff --git a/src/bees.cc b/src/bees.cc
index 98ce192..d40a964 100644
--- a/src/bees.cc
+++ b/src/bees.cc
@@ -42,11 +42,16 @@ do_cmd_help(char *argv[])
 // tracing ----------------------------------------
 
 thread_local BeesTracer *BeesTracer::tl_next_tracer = nullptr;
+thread_local bool BeesTracer::tl_first = true;
 thread_local bool BeesTracer::tl_silent = false;
 
 BeesTracer::~BeesTracer()
 {
 	if (!tl_silent && current_exception()) {
+		if (tl_first) {
+			BEESLOGNOTICE("--- BEGIN TRACE --- exception ---");
+			tl_first = false;
+		}
 		try {
 			m_func();
 		} catch (exception &e) {
@@ -61,6 +66,7 @@ BeesTracer::~BeesTracer()
 	tl_next_tracer = m_next_tracer;
 	if (!m_next_tracer) {
 		tl_silent = false;
+		tl_first = true;
 	}
 }
 
diff --git a/src/bees.h b/src/bees.h
index 48f94ad..52f4031 100644
--- a/src/bees.h
+++ b/src/bees.h
@@ -197,6 +197,7 @@ class BeesTracer {
 
 	thread_local static BeesTracer *tl_next_tracer;
 	thread_local static bool tl_silent;
+	thread_local static bool tl_first;
 public:
 	BeesTracer(function<void()> f, bool silent = false);
 	~BeesTracer();