Extend FMI2 export with DiscreteState

So far clocked Modelica states are exported as discrete FMU states.
Strict FMI 2.0 ompatibility is maintained for models without
synchronous features; no DiscreteState appears in this case.

Compiler/SimCode/SerializeModelInfo.mo

@@ -941,6 +941,10 @@ algorithm
       equation
         File.write(file,"dummy state");
       then ();
+    case BackendDAE.CLOCKED_STATE()
+      equation
+        File.write(file,"clocked state");
+      then ();
     case BackendDAE.DISCRETE()
       equation
         File.write(file,"discrete");

Compiler/SimCode/SimCode.mo

@@ -629,6 +629,12 @@ public uniontype FmiDerivatives
   end FMIDERIVATIVES;
 end FmiDerivatives;
 
+public uniontype FmiDiscreteStates
+  record FMIDISCRETESTATES
+    list<FmiUnknown> fmiUnknownsList;
+  end FMIDISCRETESTATES;
+end FmiDiscreteStates;
+
 public uniontype FmiInitialUnknowns
   record FMIINITIALUNKNOWNS
     list<FmiUnknown> fmiUnknownsList;
@@ -639,6 +645,7 @@ public uniontype FmiModelStructure
   record FMIMODELSTRUCTURE
     FmiOutputs fmiOutputs;
     FmiDerivatives fmiDerivatives;
+    FmiDiscreteStates fmiDiscreteStates;
     FmiInitialUnknowns fmiInitialUnknowns;
   end FMIMODELSTRUCTURE;
 end FmiModelStructure;

Compiler/SimCode/SimCodeUtil.mo

@@ -11306,8 +11306,8 @@ public function createFMIModelStructure
 protected
    list<tuple<DAE.ComponentRef, list<DAE.ComponentRef>>> spTA, spTB;
    list<tuple<Integer, list<Integer>>> sparseInts;
-   list<SimCode.FmiUnknown> derivatives, outputs;
-   list<SimCodeVar.SimVar> varsA, varsB;
+   list<SimCode.FmiUnknown> derivatives, outputs, discreteStates;
+   list<SimCodeVar.SimVar> varsA, varsB, clockedStates;
    SimCode.HashTableCrefToSimVar crefSimVarHT;
    list<DAE.ComponentRef> diffCrefsA, diffedCrefsA, derdiffCrefsA;
    list<DAE.ComponentRef> diffCrefsB, diffedCrefsB;
@@ -11363,13 +11363,37 @@ algorithm
     //print("-- sorted vars for CD\n");
 
     outputs := translateSparsePatterInts2FMIUnknown(sparseInts, {});
+
+    //TODO: create DiscreteStates with dependencies, like derivatives
+    clockedStates := List.filterOnTrue(inModelInfo.vars.algVars, isClockedStateSimVar);
+    discreteStates := List.map(clockedStates, createFmiUnknownFromSimVar);
+
     //print("-- finished createFMIModelStructure\n");
-    outFmiModelStructure := SOME(SimCode.FMIMODELSTRUCTURE(SimCode.FMIOUTPUTS(outputs), SimCode.FMIDERIVATIVES(derivatives), SimCode.FMIINITIALUNKNOWNS({})));
+    outFmiModelStructure := SOME(SimCode.FMIMODELSTRUCTURE(SimCode.FMIOUTPUTS(outputs), SimCode.FMIDERIVATIVES(derivatives), SimCode.FMIDISCRETESTATES(discreteStates), SimCode.FMIINITIALUNKNOWNS({})));
 else
   outFmiModelStructure := NONE();
 end try;
 end createFMIModelStructure;
 
+protected function isClockedStateSimVar
+"Returns true for state and der(state) variables, false otherwise."
+  input SimCodeVar.SimVar inVar;
+  output Boolean outBoolean;
+algorithm
+  outBoolean := match (inVar)
+    case (SimCodeVar.SIMVAR(varKind = BackendDAE.CLOCKED_STATE(_))) then true;
+    else false;
+  end match;
+end isClockedStateSimVar;
+
+protected function createFmiUnknownFromSimVar
+"create a basic FMIUNKNOWN without dependencies from a SimVar"
+  input SimCodeVar.SimVar var;
+  output SimCode.FmiUnknown unknown;
+algorithm
+  unknown := SimCode.FMIUNKNOWN(var.index + 1, {}, {});
+end createFmiUnknownFromSimVar;
+
 protected function translateSparsePatterInts2FMIUnknown
 "function translates simVar integers to fmi unknowns."
   input list<tuple<Integer, list<Integer>>> inSparsePattern;

Compiler/Template/CodegenFMU1.tpl

@@ -64,7 +64,7 @@ case SIMCODE(__) then
     <%fmiModelDescriptionAttributes(simCode,guid)%>>
     <%fmiTypeDefinitions(modelInfo, "1.0")%>
     <%DefaultExperiment(simulationSettingsOpt)%>
-    <%fmiModelVariables(modelInfo, "1.0")%>
+    <%fmiModelVariables(simCode, "1.0")%>
     <%if isFMICSType(FMUType) then Implementation()%>
   </fmiModelDescription>
   >>

Compiler/Template/CodegenFMU2.tpl

@@ -78,7 +78,7 @@ case SIMCODE(__) then
       <Category name="logFmi2Call" />
     </LogCategories>
     <%DefaultExperiment(simulationSettingsOpt)%>
-    <%fmiModelVariables(modelInfo, "2.0")%>
+    <%fmiModelVariables(simCode, "2.0")%>
     <%ModelStructureHelper(modelStructure)%>
   </fmiModelDescription>
   >>

Compiler/Template/CodegenFMUCommon.tpl

@@ -64,69 +64,71 @@ case SIMCODE(__) then
   >>
 end ModelExchange;
 
-template fmiModelVariables(ModelInfo modelInfo, String FMUVersion)
+template fmiModelVariables(SimCode simCode, String FMUVersion)
  "Generates code for ModelVariables file for FMU target."
 ::=
+match simCode
+case SIMCODE(modelInfo=modelInfo) then
 match modelInfo
 case MODELINFO(vars=SIMVARS(stateVars=stateVars)) then
   <<
   <ModelVariables>
   <%System.tmpTickReset(0)%>
   <%vars.stateVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.derivativeVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.algVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.discreteAlgVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.paramVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.aliasVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%System.tmpTickReset(0)%>
   <%vars.intAlgVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.intParamVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.intAliasVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%System.tmpTickReset(0)%>
   <%vars.boolAlgVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.boolParamVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.boolAliasVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%System.tmpTickReset(0)%>
   <%vars.stringAlgVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.stringParamVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%vars.stringAliasVars |> var =>
-    ScalarVariable(stateVars, var, FMUVersion)
+    ScalarVariable(simCode, stateVars, var, FMUVersion)
   ;separator="\n"%>
   <%System.tmpTickReset(0)%>
   <%externalFunctions(modelInfo)%>
   </ModelVariables>
   >>
 end fmiModelVariables;
 
-template ScalarVariable(list<SimVar> stateVars, SimVar simVar, String FMUVersion)
+template ScalarVariable(SimCode simCode, list<SimVar> stateVars, SimVar simVar, String FMUVersion)
  "Generates code for ScalarVariable file for FMU target."
 ::=
 match simVar
@@ -136,13 +138,16 @@ case SIMVAR(__) then
   else if stringEq(crefStr(name),"der($dummy)") then
   <<>>
   else if isFMIVersion20(FMUVersion) then
+  //if intGt(getVariableIndex(simVar), 0) then
   <<
   <!-- Index of variable = "<%getVariableIndex(simVar)%>" -->
   <ScalarVariable
-    <%ScalarVariableAttribute2(simVar)%>>
+    <%ScalarVariableAttribute2(simCode, simVar)%>>
     <%ScalarVariableType2(simVar, stateVars)%>
   </ScalarVariable>
   >>
+  //else let valueReference = '<%System.tmpTick()%>'
+  //<<>>
   else
   <<
   <ScalarVariable
@@ -302,6 +307,7 @@ case SOME(fmistruct as FMIMODELSTRUCTURE(__)) then
   <ModelStructure>
     <%ModelStructureOutputs(fmistruct.fmiOutputs)%>
     <%ModelStructureDerivatives(fmistruct.fmiDerivatives)%>
+    <%ModelStructureDiscreteStates(fmistruct.fmiDiscreteStates)%>
     <%ModelStructureInitialUnknowns(fmistruct.fmiInitialUnknowns)%>
   </ModelStructure>
   >>
@@ -336,6 +342,22 @@ case FMIDERIVATIVES(__) then
   >>
 end ModelStructureDerivatives;
 
+template ModelStructureDiscreteStates(FmiDiscreteStates fmiDiscreteStates)
+ "Generates Model Structure DiscreteStates."
+::=
+match fmiDiscreteStates
+case FMIDISCRETESTATES(__) then
+  if intGt(listLength(fmiUnknownsList), 0) then
+  <<
+  <DiscreteStates>
+    <%ModelStructureUnknowns(fmiUnknownsList)%>
+  </DiscreteStates>
+  >>
+  else
+  // don't generate if model has no discrete states for FMI 2.0 compatibility
+  <<>>
+end ModelStructureDiscreteStates;
+
 template ModelStructureInitialUnknowns(FmiInitialUnknowns fmiInitialUnknowns)
  "Generates Model Structure InitialUnknowns."
 ::=
@@ -382,7 +404,7 @@ template FmiUnknownDependenciesKind(list<String> dependenciesKind)
   >>
 end FmiUnknownDependenciesKind;
 
-template ScalarVariableAttribute2(SimVar simVar)
+template ScalarVariableAttribute2(SimCode simCode, SimVar simVar)
  "Generates code for ScalarVariable Attribute file for FMU 2.0 target."
 ::=
 match simVar
@@ -392,13 +414,15 @@ match simVar
   let variability = getVariability2(varKind, type_)
   let caus = getCausality2(causality, varKind, isValueChangeable)
   let initial = getInitialType2(variability, caus, initialValue)
+  let previous = match varKind case CLOCKED_STATE(__) then '<%getVariableIndex(cref2simvar(previousName, simCode))%>'
   <<
   name="<%System.stringReplace(crefStrNoUnderscore(name),"$", "_D_")%>"
   valueReference="<%valueReference%>"
   <%description%>
   variability="<%variability%>"
   causality="<%caus%>"
   <%if boolNot(stringEq(initial, "")) then 'initial="'+initial+'"' %>
+  <%if boolNot(stringEq(previous, "")) then 'previous="'+previous+'"' %>
   >>
 end ScalarVariableAttribute2;
 

Compiler/Template/CodegenFMUCpp.tpl

@@ -187,7 +187,7 @@ case SIMCODE(__) then
   <fmiModelDescription
     <%CodegenCppInit.fmiModelDescriptionAttributes(simCode, guid)%>>
     <%CodegenFMUCommon.DefaultExperiment(simulationSettingsOpt)%>
-    <%CodegenFMUCommon.fmiModelVariables(modelInfo,"1.0")%>
+    <%CodegenFMUCommon.fmiModelVariables(simCode, "1.0")%>
   </fmiModelDescription>
   >>
 end fmiModelDescriptionCpp;

Compiler/Template/SimCodeTV.mo

@@ -700,6 +700,12 @@ package SimCode
     end FMIDERIVATIVES;
   end FmiDerivatives;
 
+  uniontype FmiDiscreteStates
+    record FMIDISCRETESTATES
+      list<FmiUnknown> fmiUnknownsList;
+    end FMIDISCRETESTATES;
+  end FmiDiscreteStates;
+
   uniontype FmiInitialUnknowns
     record FMIINITIALUNKNOWNS
       list<FmiUnknown> fmiUnknownsList;
@@ -710,6 +716,7 @@ package SimCode
     record FMIMODELSTRUCTURE
       FmiOutputs fmiOutputs;
       FmiDerivatives fmiDerivatives;
+      FmiDiscreteStates fmiDiscreteStates;
       FmiInitialUnknowns fmiInitialUnknowns;
     end FMIMODELSTRUCTURE;
   end FmiModelStructure;
@@ -994,6 +1001,9 @@ package BackendDAE
     record STATE_DER end STATE_DER;
     record DUMMY_DER end DUMMY_DER;
     record DUMMY_STATE end DUMMY_STATE;
+    record CLOCKED_STATE
+      DAE.ComponentRef previousName "the name of the previous variable";
+    end CLOCKED_STATE;
     record DISCRETE end DISCRETE;
     record PARAM end PARAM;
     record CONST end CONST;