Redundant code removal in nested.cxx

c96c04c5ae
Replicate changes in this commit to add_symbols() for add_symbols_c().
Setting feature:immutable is now done in Allocate:cDeclaration.
Setting hasconsttype for static const variables (or constexpr) doesn't
look possible in this situation (C code for anonymous structs) - no
valid C syntax that I can figure out.

Anonymous nested structs are necessarily read-only (and set as
immutable in Swig_nested_name_unnamed_c_structs).

From https://sourceforge.net/p/swig/bugs/793/ ...

The union variable intRep below has a named type IntRepType.

typedef struct Object {
  int objtype;
  union IntRepType {
    double dvalue;
  } intRep;
} Object;

void tester() {
  /* approach (1) */
  obj.intRep.dvalue = 1.23;

  /* approach (2) */
  union IntRepType irt;
  irt.dvalue = 2.34;
  obj.intRep = irt;
}

Using C code there are two approaches to setting a value in intRep. Equivalents in perl are:

my $obj = example::Object->new();

 # approach (1)
$obj->{intRep}->{dvalue} = 3.45;

 # approach (2)
my $irt = example::IntRepType->new();
$irt->{dvalue} = 4.56;
$obj->{intRep} = $irt;

An Object_intRep_set wrapper is generated which takes type IntRepType as desired.

However, with an anonymous union:

typedef struct Object {
  int objtype;
  union IntRepType {
    double dvalue;
  } intRep;
} Object;

intRep does not have any named type name and is anonymous. It is thus not possible to create a type outside of Object to assign to intRep.
Only approach (1) is available in C and so SWIG can only provide approach (1) via wrappers too.
There is no Object_intRep_set wrapper, intRep is immutable.

Source/Modules/nested.cxx

@@ -58,22 +58,6 @@ static void add_symbols_c(Node *n) {
 	if (value && Len(value)) {
 	  Setattr(n, "hasvalue", "1");
 	}
-	if (type) {
-	  SwigType *ty;
-	  SwigType *tmp = 0;
-	  if (decl) {
-	    ty = tmp = Copy(type);
-	    SwigType_push(ty, decl);
-	  } else {
-	    ty = type;
-	  }
-	  if (!SwigType_ismutable(ty)) {
-	    SetFlag(n, "hasconsttype");
-	    SetFlag(n, "feature:immutable");
-	  }
-	  if (tmp)
-	    Delete(tmp);
-	}
 	if (!type) {
 	  Printf(stderr, "notype name %s\n", name);
 	}