[NF] Improve dimension typing.

- Try harder to deduce unknown dimensions by evaluating the
  corresponding binding if needed.

OMCompiler/Compiler/NFFrontEnd/NFTyping.mo

@@ -542,12 +542,13 @@ algorithm
   dimension := match dimension
     local
       Expression exp;
+      Option<Expression> oexp;
       Variability var;
       Dimension dim;
       Binding b;
       Type ty;
       TypingError ty_err;
-      Integer parent_dims;
+      Integer parent_dims, dim_index;
 
     // Print an error when a dimension that's currently being processed is
     // found, which indicates a dependency loop. Another way of handling this
@@ -649,14 +650,32 @@ algorithm
           // to get the dimension we're looking for.
           case Binding.UNTYPED_BINDING()
             algorithm
-              (dim, _, ty_err) := typeExpDim(b.bindingExp, index + Binding.propagatedDimCount(b) + parent_dims,
-                                             ExpOrigin.setFlag(origin, ExpOrigin.DIMENSION), info);
+              dim_index := index + Binding.propagatedDimCount(b) + parent_dims;
+              (dim, oexp, ty_err) := typeExpDim(b.bindingExp, dim_index, ExpOrigin.setFlag(origin, ExpOrigin.DIMENSION), info);
+
+              // If the deduced dimension is unknown, evaluate the binding and try again.
+              if Dimension.isUnknown(dim) and not TypingError.isError(ty_err) then
+                exp := if isSome(oexp) then Util.getOption(oexp) else b.bindingExp;
+                exp := Ceval.evalExp(exp, Ceval.EvalTarget.DIMENSION(component, index, exp, info));
+                (dim, ty_err) := nthDimensionBoundsChecked(Expression.typeOf(exp), dim_index);
+              end if;
             then
               (dim, ty_err);
 
           // A typed binding, get the dimension from the binding's type.
           case Binding.TYPED_BINDING()
-            then nthDimensionBoundsChecked(b.bindingType, index + Binding.propagatedDimCount(b) + parent_dims);
+            algorithm
+              dim_index := index + Binding.propagatedDimCount(b) + parent_dims;
+              (dim, ty_err) := nthDimensionBoundsChecked(b.bindingType, dim_index);
+
+              // If the deduced dimension is unknown, evaluate the binding and try again.
+              if Dimension.isUnknown(dim) and not TypingError.isError(ty_err) then
+                exp := Ceval.evalExp(b.bindingExp, Ceval.EvalTarget.DIMENSION(component, index, b.bindingExp, info));
+                (dim, ty_err) := nthDimensionBoundsChecked(Expression.typeOf(exp), dim_index);
+              end if;
+            then
+              (dim, ty_err);
+
         end match;
 
         () := match ty_err

testsuite/flattening/modelica/scodeinst/Makefile

@@ -710,6 +710,7 @@ RecordConstructor1.mo \
 RecordConstructor2.mo \
 RecordExtends1.mo \
 RecordExtends2.mo \
+RecordUnknownDim1.mo \
 RecursiveExtends1.mo \
 RecursiveExtends3.mo \
 RecursiveInst1.mo \

testsuite/flattening/modelica/scodeinst/RecordUnknownDim1.mo

@@ -0,0 +1,33 @@
+// name: RecordUnknownDim1
+// keywords:
+// status: correct
+// cflags: -d=newInst
+//
+//
+
+record R2
+  Integer i[:];
+end R2;
+
+record R
+  R2 r;
+end R;
+
+function f
+  output R2 r;
+algorithm
+  r := R2({1, 2});
+end f;
+
+model RecordUnknownDim1
+  R r = R(f());
+end RecordUnknownDim1;
+
+// Result:
+// class RecordUnknownDim1
+//   Integer r.r.i[1];
+//   Integer r.r.i[2];
+// equation
+//   r.r.i = {1, 2};
+// end RecordUnknownDim1;
+// endResult