From 7e6119c777fbe083c8ca7b31c79c76de12c5eb3c Mon Sep 17 00:00:00 2001
From: Niko Savola <nikosavola@taaraconnect.com>
Date: Thu, 4 Jun 2026 10:30:27 +0000
Subject: [PATCH] Make TBB linking conditional and improve backward
 compatibility of execution header guards

---
 src/db/db/db.pro             |  4 ++++
 src/db/db/dbEdgeProcessor.cc | 17 +++++++++++------
 src/db/db/dbPolygonTools.cc  | 17 +++++++++++------
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/db/db/db.pro b/src/db/db/db.pro
index d316c1c60..1c1285342 100644
--- a/src/db/db/db.pro
+++ b/src/db/db/db.pro
@@ -454,3 +454,7 @@ INCLUDEPATH += $$TL_INC $$GSI_INC
 DEPENDPATH += $$TL_INC $$GSI_INC
 LIBS += -L$$DESTDIR -lklayout_tl -lklayout_gsi
 
+packagesExist(tbb) {
+    LIBS += -ltbb
+}
+
diff --git a/src/db/db/dbEdgeProcessor.cc b/src/db/db/dbEdgeProcessor.cc
index 1b5a08391..a9f73666b 100644
--- a/src/db/db/dbEdgeProcessor.cc
+++ b/src/db/db/dbEdgeProcessor.cc
@@ -1,3 +1,14 @@
+#if __cplusplus >= 201703L
+  #if __has_include(<execution>)
+    #include <execution>
+  #endif
+#endif
+
+#if defined(__cpp_lib_execution)
+#define PARALLEL_EXEC_POLICY std::execution::par,
+#else
+#define PARALLEL_EXEC_POLICY
+#endif
 
 /*
 
@@ -29,12 +40,6 @@
 #include "tlProgress.h"
 #include "gsi.h"
 
-#if defined(__cpp_lib_execution)
-#include <execution>
-#define PARALLEL_EXEC_POLICY std::execution::par,
-#else
-#define PARALLEL_EXEC_POLICY
-#endif
 
 #include <vector>
 #include <deque>
diff --git a/src/db/db/dbPolygonTools.cc b/src/db/db/dbPolygonTools.cc
index 228a368bf..849e0a154 100644
--- a/src/db/db/dbPolygonTools.cc
+++ b/src/db/db/dbPolygonTools.cc
@@ -1,3 +1,14 @@
+#if __cplusplus >= 201703L
+  #if __has_include(<execution>)
+    #include <execution>
+  #endif
+#endif
+
+#if defined(__cpp_lib_execution)
+#define PARALLEL_EXEC_POLICY std::execution::par,
+#else
+#define PARALLEL_EXEC_POLICY
+#endif
 
 /*
 
@@ -28,12 +39,6 @@
 #include "tlLog.h"
 #include "tlInt128Support.h"
 
-#if defined(__cpp_lib_execution)
-#include <execution>
-#define PARALLEL_EXEC_POLICY std::execution::par,
-#else
-#define PARALLEL_EXEC_POLICY
-#endif
 
 #include <algorithm>
 #include <cmath>