From fd34bb2dda007d0f0f190e47ddb50f5ef4b8859a Mon Sep 17 00:00:00 2001
From: Stephen Nicholas Swatman <stephen.nicholas.swatman@cern.ch>
Date: Mon, 16 Sep 2024 11:06:01 +0200
Subject: [PATCH] Issue warnings for non-Release builds

A common pitfall when using traccc seems to be that people build it in
non-Release mode and then get poor performance. This commit adds a bunch
of warning prints to make sure that the code will inform you if you try
to run it in non-Release mode.
---
 examples/run/CMakeLists.txt                  |  5 ++++
 examples/run/common/optimization_warning.hpp | 27 ++++++++++++++++++++
 examples/run/common/throughput_mt.ipp        |  7 +++++
 examples/run/common/throughput_st.ipp        |  7 +++++
 4 files changed, 46 insertions(+)
 create mode 100644 examples/run/common/optimization_warning.hpp

diff --git a/examples/run/CMakeLists.txt b/examples/run/CMakeLists.txt
index ace69ff7be..593fcfe1dc 100644
--- a/examples/run/CMakeLists.txt
+++ b/examples/run/CMakeLists.txt
@@ -7,6 +7,11 @@
 # Project include(s).
 include( traccc-compiler-options-cpp )
 
+# Inform the code that it is being built in Release mode.
+if (${CMAKE_BUILD_TYPE} STREQUAL "Release")
+   add_definitions(-DTRACCC_BUILD_TYPE_IS_RELEASE)
+endif()
+
 # Add all the subdirectories that can be built.
 add_subdirectory(cpu)
 
diff --git a/examples/run/common/optimization_warning.hpp b/examples/run/common/optimization_warning.hpp
new file mode 100644
index 0000000000..87e7cc2ac5
--- /dev/null
+++ b/examples/run/common/optimization_warning.hpp
@@ -0,0 +1,27 @@
+/** TRACCC library, part of the ACTS project (R&D line)
+ *
+ * (c) 2022 CERN for the benefit of the ACTS project
+ *
+ * Mozilla Public License Version 2.0
+ */
+
+#pragma once
+
+#include <iostream>
+
+#if !defined(TRACCC_BUILD_TYPE_IS_RELEASE) || !defined(NDEBUG) || \
+    defined(_DEBUG)
+#define TRACCC_OPTIMIZATION_WARNING()                                         \
+    do {                                                                      \
+        std::cout                                                             \
+            << "WARNING: traccc was built without Release mode, without the " \
+               "`NDEBUG` flag, or (on MSVC) with the `_DEBUG` flag. "         \
+               "Performance is guaranteed to be much lower and compute "      \
+               "performance results should be considered unreliable!"         \
+            << std::endl;                                                     \
+    } while (false)
+#else
+#define TRACCC_OPTIMIZATION_WARNING() \
+    do {                              \
+    } while (false)
+#endif
diff --git a/examples/run/common/throughput_mt.ipp b/examples/run/common/throughput_mt.ipp
index 5e679b941c..c5cbcbee25 100644
--- a/examples/run/common/throughput_mt.ipp
+++ b/examples/run/common/throughput_mt.ipp
@@ -18,6 +18,9 @@
 #include "traccc/options/track_propagation.hpp"
 #include "traccc/options/track_seeding.hpp"
 
+// Local include(s)
+#include "optimization_warning.hpp"
+
 // I/O include(s).
 #include "traccc/io/demonstrator_edm.hpp"
 #include "traccc/io/read.hpp"
@@ -72,6 +75,8 @@ int throughput_mt(std::string_view description, int argc, char* argv[],
         argc,
         argv};
 
+    TRACCC_OPTIMIZATION_WARNING();
+
     // Set up the timing info holder.
     performance::timing_info times;
 
@@ -242,6 +247,7 @@ int throughput_mt(std::string_view description, int argc, char* argv[],
     // Print some results.
     std::cout << "Reconstructed track parameters: " << rec_track_params.load()
               << std::endl;
+    TRACCC_OPTIMIZATION_WARNING();
     std::cout << "Time totals:" << std::endl;
     std::cout << times << std::endl;
     std::cout << "Throughput:" << std::endl;
@@ -251,6 +257,7 @@ int throughput_mt(std::string_view description, int argc, char* argv[],
               << performance::throughput{throughput_opts.processed_events,
                                          times, "Event processing"}
               << std::endl;
+    TRACCC_OPTIMIZATION_WARNING();
 
     // Print results to log file
     if (throughput_opts.log_file != "\0") {
diff --git a/examples/run/common/throughput_st.ipp b/examples/run/common/throughput_st.ipp
index ad605e4f56..1ce8f9c478 100644
--- a/examples/run/common/throughput_st.ipp
+++ b/examples/run/common/throughput_st.ipp
@@ -17,6 +17,9 @@
 #include "traccc/options/track_propagation.hpp"
 #include "traccc/options/track_seeding.hpp"
 
+// Local include(s)
+#include "optimization_warning.hpp"
+
 // I/O include(s).
 #include "traccc/io/demonstrator_edm.hpp"
 #include "traccc/io/read.hpp"
@@ -62,6 +65,8 @@ int throughput_st(std::string_view description, int argc, char* argv[],
         argc,
         argv};
 
+    TRACCC_OPTIMIZATION_WARNING();
+
     // Set up the timing info holder.
     performance::timing_info times;
 
@@ -192,6 +197,7 @@ int throughput_st(std::string_view description, int argc, char* argv[],
     // Print some results.
     std::cout << "Reconstructed track parameters: " << rec_track_params
               << std::endl;
+    TRACCC_OPTIMIZATION_WARNING();
     std::cout << "Time totals:" << std::endl;
     std::cout << times << std::endl;
     std::cout << "Throughput:" << std::endl;
@@ -201,6 +207,7 @@ int throughput_st(std::string_view description, int argc, char* argv[],
               << performance::throughput{throughput_opts.processed_events,
                                          times, "Event processing"}
               << std::endl;
+    TRACCC_OPTIMIZATION_WARNING();
 
     // Return gracefully.
     return 0;