From 7a8e08cac71924a301d96dbac6dcb283677e93b1 Mon Sep 17 00:00:00 2001
From: Sung Yoon Whang <suwhang@microsoft.com>
Date: Mon, 21 Oct 2019 16:04:28 -0700
Subject: [PATCH] Fix LTTng build for build environments with older
 liblttng-ust-dev  (#27273) (#27294)

* Fix macro redefinition to use XplatEventLogger instead of simply writing FALSE

* Fix linker error

* undo newline changes

* Some changes to comment

* Move wrapper export from eventpipe.cpp to eventtrace.cpp
---
 src/scripts/genLttngProvider.py | 5 ++++-
 src/vm/eventtrace.cpp           | 8 ++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/scripts/genLttngProvider.py b/src/scripts/genLttngProvider.py
index 38fca2d09bb1..393ca3f4c022 100644
--- a/src/scripts/genLttngProvider.py
+++ b/src/scripts/genLttngProvider.py
@@ -546,7 +546,10 @@ def generateLttngFiles(etwmanifest,eventprovider_directory, dryRun):
                 lttngimpl_file.write("#include \"" + lttngevntheadershortname + "\"\n\n")
 
                 lttngimpl_file.write("""#ifndef tracepoint_enabled
-#define tracepoint_enabled(provider, name) FALSE
+
+extern "C" bool XplatEventLoggerIsEnabled();
+
+#define tracepoint_enabled(provider, name) XplatEventLoggerIsEnabled()
 #define do_tracepoint tracepoint
 #endif
 
diff --git a/src/vm/eventtrace.cpp b/src/vm/eventtrace.cpp
index f5f6389d89a1..ec0940074578 100644
--- a/src/vm/eventtrace.cpp
+++ b/src/vm/eventtrace.cpp
@@ -7543,3 +7543,11 @@ bool EventPipeHelper::IsEnabled(DOTNET_TRACE_CONTEXT Context, UCHAR Level, ULONG
     return false;
 }
 #endif // FEATURE_PERFTRACING
+
+#if defined(FEATURE_PAL)  && defined(FEATURE_PERFTRACING)
+// This is a wrapper method for LTTng. See https://github.com/dotnet/coreclr/pull/27273 for details.
+extern "C" bool XplatEventLoggerIsEnabled()
+{
+    return XplatEventLogger::IsEventLoggingEnabled();
+}
+#endif // FEATURE_PAL && FEATURE_PERFTRACING