Fix dumping of flat model with NB (#14627)

- Return the OB function tree that's used in `NSimCode.SimCode.create`
  so it can be reused when dumping the flat model, since the conversion
  is destructive and can fail if done twice.

Author: perost

OMCompiler/Compiler/NFFrontEnd/NFConvertDAE.mo

@@ -80,7 +80,17 @@ protected
   DAE.Element class_elem;
 algorithm
   daeFunctions := convertFunctionTree(functions);
+  dae := convertModel(flatModel);
+  execStat(getInstanceName());
+end convert;
 
+function convertModel
+  input FlatModel flatModel;
+  output DAE.DAElist dae;
+protected
+  list<DAE.Element> elems;
+  DAE.Element class_elem;
+algorithm
   elems := convertVariables(flatModel.variables, {});
   elems := convertEquations(flatModel.equations, elems);
   elems := convertInitialEquations(flatModel.initialEquations, elems);
@@ -89,9 +99,7 @@ algorithm
 
   class_elem := DAE.COMP(FlatModel.fullName(flatModel), elems, flatModel.source, ElementSource.getOptComment(flatModel.source));
   dae := DAE.DAE({class_elem});
-
-  execStat(getInstanceName());
-end convert;
+end convertModel;
 
 function convertStatements
   input list<Statement> statements;

OMCompiler/Compiler/NSimCode/NSimCode.mo

@@ -270,6 +270,7 @@ public
       input String fileNamePrefix;
       input Option<OldSimCode.SimulationSettings> simSettingsOpt;
       output SimCode simCode;
+      output DAE.FunctionTree oldFunctionTree;
     protected
       partial function mapExp
         input output Expression exp;
@@ -400,7 +401,10 @@ public
             // Will probably be mostly the same in all other regards
             program := SymbolTable.getAbsyn();
             directory := CevalScriptBackend.getFileDir(AbsynUtil.pathToCref(name), program);
-            (libs, libPaths, _, includeDirs, recordDecls, functions, _) := OldSimCodeUtil.createFunctions(program, ConvertDAE.convertFunctionTree(funcTree));
+            // The OB function tree is needed both here and when dumping the flat model,
+            // but converting it is destructive so return it to avoid doing it again.
+            oldFunctionTree := ConvertDAE.convertFunctionTree(funcTree);
+            (libs, libPaths, _, includeDirs, recordDecls, functions, _) := OldSimCodeUtil.createFunctions(program, oldFunctionTree);
             makefileParams := OldSimCodeFunctionUtil.createMakefileParams(includeDirs, libs, libPaths, false, false);
 
             (linearLoops, nonlinearLoops, jacobians, simCodeIndices) := collectAlgebraicLoops(init, init_0, ode, algebraic, daeModeData, simCodeIndices, simcode_map);

OMCompiler/Compiler/SimCode/SimCodeMain.mo

@@ -394,6 +394,7 @@ function generateModelCodeNewBackend
   output String fileDir;
   output Real timeSimCode = 0.0;
   output Real timeTemplates = 0.0;
+  output DAE.FunctionTree oldFunctionTree;
 protected
   Integer numCheckpoints;
   NSimCode.SimCode simCode;
@@ -403,7 +404,7 @@ algorithm
   StackOverflow.clearStacktraceMessages();
   try
     System.realtimeTick(ClockIndexes.RT_CLOCK_SIMCODE);
-    simCode := NSimCode.SimCode.create(bdae, className, fileNamePrefix, simSettingsOpt);
+    (simCode, oldFunctionTree) := NSimCode.SimCode.create(bdae, className, fileNamePrefix, simSettingsOpt);
     if Flags.isSet(Flags.DUMP_SIMCODE) then
       print(NSimCode.SimCode.toString(simCode));
     end if;
@@ -1172,15 +1173,17 @@ algorithm
     ExecStat.execStat("FrontEnd");
 
     if runBackend then
-      (outLibs, outFileDir, resultValues) := translateModelCallBackendNB(flatModel, funcTree, className, inFileNamePrefix, inSimSettingsOpt);
+      (outLibs, outFileDir, resultValues, funcs) := translateModelCallBackendNB(flatModel, funcTree, className, inFileNamePrefix, inSimSettingsOpt);
+    else
+      funcs := NFConvertDAE.convertFunctionTree(funcTree);
     end if;
 
     // This must be done after calling the backend since it uses the FlatModel,
     // and converting it to DAE is destructive.
     if dumpValidFlatModelicaNF then
       flatString := NFFlatString;
     elseif not runSilent then
-      (dae, funcs) := NFConvertDAE.convert(flatModel, funcTree);
+      dae := NFConvertDAE.convertModel(flatModel);
       flatString := DAEDump.dumpStr(dae, funcs);
     end if;
 
@@ -1476,6 +1479,7 @@ protected function translateModelCallBackendNB
   output list<String> outLibs;
   output String outFileDir;
   output list<tuple<String, Values.Value>> resultValues;
+  output DAE.FunctionTree oldFunctionTree;
 protected
   Real timeSimCode=0.0, timeTemplates=0.0, timeBackend=0.0;
   NBackendDAE bdae;
@@ -1493,7 +1497,7 @@ algorithm
   timeBackend := System.realtimeTock(ClockIndexes.RT_CLOCK_BACKEND);
   ExecStat.execStat("backend");
 
-  (outLibs, outFileDir, timeSimCode, timeTemplates) := generateModelCodeNewBackend(bdae, inClassName, inFileNamePrefix, inSimSettingsOpt);
+  (outLibs, outFileDir, timeSimCode, timeTemplates, oldFunctionTree) := generateModelCodeNewBackend(bdae, inClassName, inFileNamePrefix, inSimSettingsOpt);
 
   resultValues := {("timeTemplates", Values.REAL(timeTemplates)),
                   ("timeSimCode", Values.REAL(timeSimCode)),