[FMI] Set default dense and sparse linear solvers

Belonging to [master]:
  - #1907

Author: sjoelund

SimulationRuntime/c/simulation/simulation_runtime.cpp

@@ -268,8 +268,9 @@ static int getlinearSparseSolverMethod()
   const char *cflags = omc_flagValue[FLAG_LSS];
   const string *method = cflags ? new string(cflags) : NULL;
 
-  if(!method)
-    return LSS_KLU; /* default method */
+  if (!method) {
+    return LSS_DEFAULT; /* default method */
+  }
 
   for(i=1; i<LSS_MAX; ++i)
     if(*method == LSS_NAME[i])

SimulationRuntime/c/simulation/solver/linearSystem.c

@@ -120,36 +120,47 @@ int initializeLinearSystems(DATA *data, threadData_t *threadData)
     {
       switch(data->simulationInfo->lssMethod)
       {
-    #if !defined(OMC_MINIMAL_RUNTIME)
-      case LSS_LIS:
-        linsys[i].setAElement = setAElementLis;
-        linsys[i].setBElement = setBElementLis;
-        allocateLisData(size, size, nnz, linsys[i].solverData);
-        break;
-    #endif
     #ifdef WITH_UMFPACK
       case LSS_UMFPACK:
         linsys[i].setAElement = setAElementUmfpack;
         linsys[i].setBElement = setBElement;
         allocateUmfPackData(size, size, nnz, linsys[i].solverData);
         break;
+      case LSS_DEFAULT:
       case LSS_KLU:
         linsys[i].setAElement = setAElementKlu;
         linsys[i].setBElement = setBElement;
         allocateKluData(size, size, nnz, linsys[i].solverData);
         break;
     #else
+      case LSS_KLU:
       case LSS_UMFPACK:
-        throwStreamPrint(threadData, "OMC is compiled without UMFPACK, if you want use umfpack please compile OMC with UMFPACK.");
+        throwStreamPrint(threadData, "OMC is compiled without UMFPACK, if you want use klu or umfpack please compile OMC with UMFPACK.");
         break;
     #endif
-
+    #if !defined(OMC_MINIMAL_RUNTIME)
+    #if !defined(WITH_UMFPACK)
+      case LSS_DEFAULT:
+    #endif
+      case LSS_LIS:
+        linsys[i].setAElement = setAElementLis;
+        linsys[i].setBElement = setBElementLis;
+        allocateLisData(size, size, nnz, linsys[i].solverData);
+        break;
+    #endif
+    #if defined(OMC_MINIMAL_RUNTIME) && !defined(WITH_UMFPACK)
+      case LSS_DEFAULT:
+        {
+          int indexes[2] = {1, linsys[i].index};
+          infoStreamPrintWithEquationIndexes(LOG_STDOUT, 0, indexes, "The simulation runtime does not have access to sparse solvers. Defaulting to a dense linear system solver instead.");
+          break;
+        }
+    #endif
       default:
         throwStreamPrint(threadData, "unrecognized linear solver");
       }
     }
-
-    else{
+    if(linsys[i].useSparseSolver == 0) { /* Not an else-statement because there might not be a sparse linear solver available */
     switch(data->simulationInfo->lsMethod)
     {
       case LS_LAPACK:

SimulationRuntime/c/simulation/solver/model_help.c

@@ -940,8 +940,8 @@ void initializeDataStruc(DATA *data, threadData_t *threadData)
   data->simulationInfo->nlsMethod = NLS_HOMOTOPY;
 #endif
   data->simulationInfo->nlsLinearSolver = NLS_LS_LAPACK;
-  data->simulationInfo->lsMethod = LS_LAPACK;
-  data->simulationInfo->lssMethod = LS_UMFPACK;
+  data->simulationInfo->lsMethod = LS_DEFAULT;
+  data->simulationInfo->lssMethod = LSS_DEFAULT;
   data->simulationInfo->mixedMethod = MIXED_SEARCH;
   data->simulationInfo->newtonStrategy = NEWTON_PURE;
   data->simulationInfo->nlsCsvInfomation = 0;

SimulationRuntime/c/util/simulation_options.c

@@ -679,7 +679,7 @@ const char *LS_DESC[LS_MAX] = {
 
 const char *LSS_NAME[LS_MAX] = {
   "LS_UNKNOWN",
-
+                        "default",
 #if !defined(OMC_MINIMAL_RUNTIME)
   /* LS_LIS */          "lis",
 #else
@@ -691,7 +691,7 @@ const char *LSS_NAME[LS_MAX] = {
 
 const char *LSS_DESC[LS_MAX] = {
   "unknown",
-
+                        "the default sparse linear solver (or a dense solver if there is none available)"
 #if !defined(OMC_MINIMAL_RUNTIME)
   /* LS_LIS */          "method using iterative solver Lis",
 #else

SimulationRuntime/c/util/simulation_options.h

@@ -214,14 +214,14 @@ enum LINEAR_SPARSE_SOLVER
 {
   LSS_NONE = 0,
 
+  LSS_DEFAULT,
 #if !defined(OMC_MINIMAL_RUNTIME)
   LSS_LIS,
 #else
   LSS_LIS_NOT_AVAILABLE,
 #endif
   LSS_KLU,
   LSS_UMFPACK,
-
   LSS_MAX
 };