Further fixes to ASUB bug in Exp.simlify.

Added dummy state always present to make dassl happy if run with model without states.

git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@1979 f25d12d1-65f4-0310-ae8a-bbce733d8d8e

Compiler/DAELow.rml

@@ -356,6 +356,7 @@ relation lower: (DAE.DAElist) => DAELow =
 
   rule	states(lst,empty_bintree) => s &
 	lower2(lst,s,[]) => (vars,knvars,eqns,reqns,ieqns,algs,whenclauses)  &
+	add_dummy_state(vars,eqns) => (vars,eqns) &
 	list_reverse whenclauses => whenclauses' &
 	lower_algorithms(vars,algs) => algeqns &
 	list_append(algeqns,eqns) => eqns &
@@ -373,6 +374,31 @@ relation lower: (DAE.DAElist) => DAELow =
 	  => DAELOW(vars',knvars,eqnarr,reqnarr,ieqnarr,algarr,EVENT_INFO(whenclauses',zero_crossings))
 end
 
+(** relation: add_dummy_state
+ **
+ ** In order for the solver to work correctly at least one state variable
+ ** must exist in the equation system. This relation therefore adds a 
+ ** dummy state variable and an equation for that variable.
+**)
+relation  add_dummy_state: (Variables, (* vars*)
+			    Equation list) (*eqns*) 
+	  => (Variables, 
+	      Equation list) =
+
+  rule	add_var(VAR(Exp.CREF_IDENT("$dummy",[]),STATE,DAE.BIDIR,DAE.REAL,
+		    NONE,NONE,[],NONE,-1,"$dummy",[],NONE,NONE,
+		    DAE.NON_CONNECTOR),vars) => vars' 
+
+	-------------------
+	add_dummy_state(vars,eqns) 
+	  => (vars',
+	      EQUATION(Exp.CALL(Absyn.IDENT("der"),
+				[Exp.CREF(Exp.CREF_IDENT("$dummy",[]),Exp.REAL)],
+				false,
+				true),
+		       Exp.RCONST(0.0))::eqns)
+end
+
 (** relation: dump_zc_str
  **
  ** Dumps a zerocrossing into a string, for debugging purposes.

Compiler/Exp.rml

@@ -1404,11 +1404,30 @@ relation simplify_asub: (Exp, int) => Exp =
 	simplify_asub(BINARY(e1,DIV_ARRAY_SCALAR(t),e2),indx)
 	  => (BINARY(e1',DIV_ARRAY_SCALAR(t),e2'))
 
-	  (* arbitrary binary expressions *)
   rule	simplify_asub(e1,indx) => e1' &
 	simplify_asub(e2,indx) => e2' 
+	----------------------------
+	simplify_asub(BINARY(e1,ADD_ARR(t),e2),indx)
+	  => (BINARY(e1',ADD_ARR(t),e2'))
+
+  rule	simplify_asub(e1,indx) => e1' &
+	simplify_asub(e2,indx) => e2' 
+	----------------------------
+	simplify_asub(BINARY(e1,SUB_ARR(t),e2),indx)
+	  => (BINARY(e1',SUB_ARR(t),e2'))
+
+
+  rule	int_sub (indx,1) => i' &
+	list_nth(exps,i') => exp
+	-----------------------
+	simplify_asub (ARRAY(t,b,exps),indx) => exp
+
+  rule	int_sub (indx,1) => i' &
+	list_nth(exps,i') => (expl) &
+	Util.split_tuple2_list(expl) => (expl',bls) &
+	Util.bool_and_list(bls) => b
 	-----------------------
-	simplify_asub(BINARY(e1,op,e2),indx) => BINARY(e1',op,e2')
+	simplify_asub( MATRIX(t,n,exps),indx) => ARRAY(t,b,expl')
 
   rule	simplify(ASUB(e,indx)) => e'
 	--------------------------------