From e6d873d3c0ece99d2af236e183b5c381335109a6 Mon Sep 17 00:00:00 2001
From: Shahzad Malik Muzaffar <shahzad.malik.muzaffar@cern.ch>
Date: Tue, 10 Feb 2026 14:09:55 +0100
Subject: [PATCH] Testing GCC with -fimplicit-constexpr

---
 scram-tools.file/tools/gcc/gcc-cxxcompiler.xml   | 1 +
 scram-tools.file/tools/icx/icx-cxxcompiler.xml   | 1 +
 scram-tools.file/tools/llvm/llvm-cxxcompiler.xml | 1 +
 3 files changed, 3 insertions(+)

diff --git a/scram-tools.file/tools/gcc/gcc-cxxcompiler.xml b/scram-tools.file/tools/gcc/gcc-cxxcompiler.xml
index 6d84b7780fb..b1fcc9aacc1 100644
--- a/scram-tools.file/tools/gcc/gcc-cxxcompiler.xml
+++ b/scram-tools.file/tools/gcc/gcc-cxxcompiler.xml
@@ -15,6 +15,7 @@
 %endif
     <flags CXXFLAGS="-Werror=overlength-strings -Wno-vla @GCC_CXXFLAGS@"/>
     <flags CXXFLAGS="-felide-constructors -fmessage-length=0"/>
+    <flags CXXFLAGS="-fimplicit-constexpr"/>
     <flags CXXFLAGS="-Wall -Wno-non-template-friend -Wno-long-long -Wreturn-type"/>
     <flags CXXFLAGS="-Wextra -Wpessimizing-move -Wclass-memaccess"/>
     <flags CXXFLAGS="-Wno-cast-function-type -Wno-unused-but-set-parameter -Wno-ignored-qualifiers -Wno-unused-parameter"/>
diff --git a/scram-tools.file/tools/icx/icx-cxxcompiler.xml b/scram-tools.file/tools/icx/icx-cxxcompiler.xml
index 984887d13cc..dc7e9c6cd6e 100644
--- a/scram-tools.file/tools/icx/icx-cxxcompiler.xml
+++ b/scram-tools.file/tools/icx/icx-cxxcompiler.xml
@@ -6,6 +6,7 @@
       <environment name="LIBDIR" default="$ICX_CXXCOMPILER_BASE/lib"/>
     </client>
     <flags REM_CXXFLAGS="-felide-constructors"/>
+    <flags REM_CXXFLAGS="-fimplicit-constexpr"/>
     <flags REM_CXXFLAGS="-ftree-vectorize"/>
     <flags REM_CXXFLAGS="-fno-crossjumping"/>
     <flags REM_CXXFLAGS="-Wno-non-template-friend"/>
diff --git a/scram-tools.file/tools/llvm/llvm-cxxcompiler.xml b/scram-tools.file/tools/llvm/llvm-cxxcompiler.xml
index 5fb434b0dc8..4d437993b36 100644
--- a/scram-tools.file/tools/llvm/llvm-cxxcompiler.xml
+++ b/scram-tools.file/tools/llvm/llvm-cxxcompiler.xml
@@ -11,6 +11,7 @@
     <flags REM_CXXFLAGS="-Werror=maybe-uninitialized"/>
     <flags REM_CXXFLAGS="-Werror=unused-but-set-variable"/>
     <flags REM_CXXFLAGS="-Werror=return-local-addr"/>
+    <flags REM_CXXFLAGS="-fimplicit-constexpr"/>
     <flags REM_CXXFLAGS="-fipa-pta"/>
     <flags REM_CXXFLAGS="-frounding-math"/>
     <flags REM_CXXFLAGS="-mrecip"/>