add the FILEUNIT keyword

currently, this keyword is basically ignored: setting the unit system
of a file to something different than the deck unit system will cause
`Opm::checkDeck()` to produce a warning.

opm/parser/eclipse/Parser/ParseContext.hpp

@@ -217,6 +217,12 @@ namespace Opm {
         */
         const static std::string PARSE_LONG_KEYWORD;
 
+        /*
+          The unit system specified via the FILEUNIT keyword is different from the unit
+          system used by the deck.
+        */
+        const static std::string UNIT_SYSTEM_MISMATCH;
+
         /*
           Some property modfiers can be modified in the Schedule
           section; this effectively means that Eclipse supports time

src/opm/parser/eclipse/EclipseState/checkDeck.cpp

@@ -50,6 +50,21 @@ bool checkDeck( const Deck& deck, const Parser& parser, const ParseContext& pars
         deckValid = deckValid && Section::checkSectionTopology(deck, parser, ensureKeywordSection);
     }
 
+    const std::string& deckUnitSystem = deck.getActiveUnitSystem().getName();
+    for (const auto& keyword : deck.getKeywordList("FILEUNIT")) {
+        const std::string& fileUnitSystem =
+            keyword->getRecord(0).getItem("FILE_UNIT_SYSTEM").getTrimmedString(0);
+        if (fileUnitSystem != deckUnitSystem) {
+            std::string msg =
+                "Unit system " + fileUnitSystem + " specified via the FILEUNIT keyword at "
+                + keyword->getFileName() + ":" + std::to_string(keyword->getLineNumber())
+                + " does not correspond to the unit system used by the deck ("
+                + deckUnitSystem + ")";
+            parseContext.handleError(ParseContext::UNIT_SYSTEM_MISMATCH, msg, errorGuard);
+            deckValid = false;
+        }
+    }
+
     return deckValid;
 }
 }

src/opm/parser/eclipse/Parser/ParseContext.cpp

@@ -79,6 +79,8 @@ namespace Opm {
         addKey(PARSE_MISSING_INCLUDE, InputError::EXIT1);
         addKey(PARSE_LONG_KEYWORD, InputError::WARN);
 
+        addKey(UNIT_SYSTEM_MISMATCH, InputError::THROW_EXCEPTION);
+
         this->addKey(RUNSPEC_NUMWELLS_TOO_LARGE, InputError::DELAYED_EXIT1);
         this->addKey(RUNSPEC_CONNS_PER_WELL_TOO_LARGE, InputError::DELAYED_EXIT1);
         this->addKey(RUNSPEC_NUMGROUPS_TOO_LARGE, InputError::DELAYED_EXIT1);
@@ -310,6 +312,8 @@ namespace Opm {
     const std::string ParseContext::PARSE_MISSING_INCLUDE = "PARSE_MISSING_INCLUDE";
     const std::string ParseContext::PARSE_LONG_KEYWORD = "PARSE_LONG_KEYWORD";
 
+    const std::string ParseContext::UNIT_SYSTEM_MISMATCH = "UNIT_SYSTEM_MISMATCH";
+
     const std::string ParseContext::RUNSPEC_NUMWELLS_TOO_LARGE = "RUNSPEC_NUMWELLS_TOO_LARGE";
     const std::string ParseContext::RUNSPEC_CONNS_PER_WELL_TOO_LARGE = "RUNSPEC_CONNS_PER_WELL_TOO_LARGE";
     const std::string ParseContext::RUNSPEC_NUMGROUPS_TOO_LARGE = "RUNSPEC_NUMGROUPS_TOO_LARGE";

src/opm/parser/eclipse/share/keywords/000_Eclipse100/F/FILEUNIT

@@ -0,0 +1,8 @@
+{
+ "name": "FILEUNIT",
+ "sections": ["GRID", "EDIT", "PROPS", "REGIONS", "SOLUTION", "SCHEDULE"],
+ "size":1,
+ "items":[
+ {"name" : "FILE_UNIT_SYSTEM", "value_type" : "STRING"}
+]}
+

src/opm/parser/eclipse/share/keywords/keyword_list.cmake

@@ -98,6 +98,7 @@ set( keywords
      000_Eclipse100/F/FAULTS
      000_Eclipse100/F/FIELD
      000_Eclipse100/F/FIELD_PROBE
+     000_Eclipse100/F/FILEUNIT
      000_Eclipse100/F/FILLEPS
      000_Eclipse100/F/FIPOWG
      000_Eclipse100/F/FIP_PROBE