Populate Region Variable Mapping From Summary Config

This commit adds a special purpose helper function,

    populateRegVarMapping()

that, based on the run's configured summary vectors, populates an
object of type data::RegionVariableMapping.

In this initial implementation, we define a variable named

    ConnOPT

if any of the *OEW* summary vectors are configured in the run's
SUMMARY section.  Those OEW vectors require tracking the per-region
cumulative oil production from wells and it's easier to have a
dedicated variable for this than to introduce extra "COPT" summary
vectors that are visible to the user through the result set's
summary files (e.g., .SMSPEC and .UNSMRY).

Author: bska

CMakeLists_files.cmake

@@ -146,6 +146,7 @@ list(APPEND MAIN_SOURCE_FILES
   opm/input/eclipse/EclipseState/SimulationConfig/RockConfig.cpp
   opm/input/eclipse/EclipseState/SimulationConfig/SimulationConfig.cpp
   opm/input/eclipse/EclipseState/SimulationConfig/ThresholdPressure.cpp
+  opm/input/eclipse/EclipseState/SummaryConfig/RegionVariableSupport.cpp
   opm/input/eclipse/EclipseState/SummaryConfig/SummaryConfig.cpp
   opm/input/eclipse/EclipseState/Tables/Aqudims.cpp
   opm/input/eclipse/EclipseState/Tables/ColumnSchema.cpp
@@ -1011,6 +1012,7 @@ list(APPEND PUBLIC_HEADER_FILES
   opm/input/eclipse/EclipseState/SimulationConfig/RockConfig.hpp
   opm/input/eclipse/EclipseState/SimulationConfig/SimulationConfig.hpp
   opm/input/eclipse/EclipseState/SimulationConfig/ThresholdPressure.hpp
+  opm/input/eclipse/EclipseState/SummaryConfig/RegionVariableSupport.hpp
   opm/input/eclipse/EclipseState/SummaryConfig/SummaryConfig.hpp
   opm/input/eclipse/EclipseState/Tables/Aqudims.hpp
   opm/input/eclipse/EclipseState/Tables/AqutabTable.hpp

opm/input/eclipse/EclipseState/SummaryConfig/RegionVariableSupport.cpp

@@ -0,0 +1,64 @@
+/*
+  Copyright 2026 Equinor ASA.
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <opm/input/eclipse/EclipseState/SummaryConfig/RegionVariableSupport.hpp>
+
+#include <opm/output/data/RegionVariableMapping.hpp>
+
+#include <opm/input/eclipse/EclipseState/SummaryConfig/SummaryConfig.hpp>
+
+namespace {
+    void populateOilEfficiencyVariables(const Opm::SummaryConfig&         sumcfg,
+                                        Opm::data::RegionVariableMapping& regVarMap)
+    {
+        // FOEW, ROEW, ROEW_<REG>
+        const auto oew_kws = sumcfg.keywords(R"(*OEW*)");
+
+        if (oew_kws.empty()) {
+            // No *OEW* vectors requested.  Nothing to do.
+            return;
+        }
+
+        using RegSet = Opm::data::RegionVariableMapping::RegionSet;
+
+        regVarMap.add(Opm::data::RegionVariableMapping::Variable { "ConnOPT" },
+                      /* is_cumulative = */ true);
+
+        for (const auto& oew_kw : oew_kws) {
+            if (oew_kw.category() == Opm::SummaryConfigNode::Category::Region) {
+                regVarMap.add(RegSet { oew_kw.fip_region() });
+            }
+            else {
+                // Not a region level vector.  Typically FOEW.  Ensure that
+                // we have FIPNUM for this case.
+                regVarMap.add(RegSet { "FIPNUM" });
+            }
+        }
+    }
+} // Anonymous namespace
+
+// ===========================================================================
+// Public interface below separator
+// ===========================================================================
+
+void Opm::populateRegVarMapping(const SummaryConfig&         sumcfg,
+                                data::RegionVariableMapping& regVarMap)
+{
+    populateOilEfficiencyVariables(sumcfg, regVarMap);
+}

opm/input/eclipse/EclipseState/SummaryConfig/RegionVariableSupport.hpp

@@ -0,0 +1,36 @@
+/*
+  Copyright 2026 Equinor ASA.
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef OPM_REGION_VARIABLE_SUPPORT_HPP
+#define OPM_REGION_VARIABLE_SUPPORT_HPP
+
+namespace Opm {
+    class SummaryConfig;
+} // namespace Opm
+
+namespace Opm::data {
+    class RegionVariableMapping;
+} // namespace Opm::data
+
+namespace Opm {
+    void populateRegVarMapping(const SummaryConfig&         sumcfg,
+                               data::RegionVariableMapping& regVarMap);
+}
+
+#endif // OPM_REGION_VARIABLE_SUPPORT_HPP