Fix Java %interface family of macros

when returning by const pointer reference

Closes #1987

CHANGES.current

@@ -7,6 +7,10 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2021-04-27: wsfulton
+            #1987 [Java] Fix %interface family of macros for returning by const
+            pointer reference.
+
 2021-04-19: olly
 	    Fix use of uninitialised variable in the generated code for an
 	    empty typecheck typemap, such as the dummy one we include for

Examples/test-suite/csharp/multiple_inheritance_abstract_runme.cs

@@ -216,6 +216,7 @@ public class multiple_inheritance_abstract_runme {
     check(multiple_inheritance_abstract.InputCPtrRefBottom1(b1)!=103+104, "InputCPtrRefBottom1() failed");
     check(multiple_inheritance_abstract.InputCPtrRefBottom2(b2)!=206+205, "InputCPtrRefBottom2() failed");
     check(multiple_inheritance_abstract.InputCPtrRefBottom3(b3)!=307+308+309, "InputCPtrRefBottom3() failed");
+
     // Return pointers
     check(multiple_inheritance_abstract.MakePtrDerived1_CBase1().cbase1y()!=3, "MakePtrDerived1_CBase1 failed");
     check(multiple_inheritance_abstract.MakePtrDerived1_CBase2().cbase2()!=4, "MakePtrDerived1_CBase2 failed");
@@ -234,6 +235,15 @@ public class multiple_inheritance_abstract_runme {
     check(multiple_inheritance_abstract.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_abstract.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_abstract.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_abstract.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/csharp/multiple_inheritance_nspace_runme.cs

@@ -217,6 +217,7 @@ public class multiple_inheritance_nspace_runme {
     check(multiple_inheritance_nspace.InputCPtrRefBottom1(b1)!=103+104, "InputCPtrRefBottom1() failed");
     check(multiple_inheritance_nspace.InputCPtrRefBottom2(b2)!=206+205, "InputCPtrRefBottom2() failed");
     check(multiple_inheritance_nspace.InputCPtrRefBottom3(b3)!=307+308+309, "InputCPtrRefBottom3() failed");
+
     // Return pointers
     check(multiple_inheritance_nspace.MakePtrDerived1_CBase1().cbase1y()!=3, "MakePtrDerived1_CBase1 failed");
     check(multiple_inheritance_nspace.MakePtrDerived1_CBase2().cbase2()!=4, "MakePtrDerived1_CBase2 failed");
@@ -235,6 +236,15 @@ public class multiple_inheritance_nspace_runme {
     check(multiple_inheritance_nspace.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_nspace.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_nspace.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_nspace.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/csharp/multiple_inheritance_shared_ptr_runme.cs

@@ -301,6 +301,15 @@ public class multiple_inheritance_shared_ptr_runme {
     check(multiple_inheritance_shared_ptr.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_shared_ptr.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_shared_ptr.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_shared_ptr.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/java/multiple_inheritance_abstract_runme.java

@@ -224,6 +224,7 @@ public class multiple_inheritance_abstract_runme {
     check(multiple_inheritance_abstract.InputCPtrRefBottom1(b1)!=103+104, "InputCPtrRefBottom1() failed");
     check(multiple_inheritance_abstract.InputCPtrRefBottom2(b2)!=206+205, "InputCPtrRefBottom2() failed");
     check(multiple_inheritance_abstract.InputCPtrRefBottom3(b3)!=307+308+309, "InputCPtrRefBottom3() failed");
+
     // Return pointers
     check(multiple_inheritance_abstract.MakePtrDerived1_CBase1().cbase1y()!=3, "MakePtrDerived1_CBase1 failed");
     check(multiple_inheritance_abstract.MakePtrDerived1_CBase2().cbase2()!=4, "MakePtrDerived1_CBase2 failed");
@@ -242,6 +243,15 @@ public class multiple_inheritance_abstract_runme {
     check(multiple_inheritance_abstract.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_abstract.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_abstract.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_abstract.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_abstract.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/java/multiple_inheritance_nspace_runme.java

@@ -244,6 +244,15 @@ public class multiple_inheritance_nspace_runme {
     check(multiple_inheritance_nspace.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_nspace.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_nspace.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_nspace.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_nspace.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/java/multiple_inheritance_shared_ptr_runme.java

@@ -309,6 +309,15 @@ public class multiple_inheritance_shared_ptr_runme {
     check(multiple_inheritance_shared_ptr.MakeRefDerived3_CBase1().cbase1y()!=7, "MakeRefDerived3_CBase1 failed");
     check(multiple_inheritance_shared_ptr.MakeRefDerived3_CBase2().cbase2()!=8, "MakeRefDerived3_CBase2 failed");
 
+    // Return const pointer references
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived1_CBase1().cbase1y()!=3, "MakeConstPtrRefDerived1_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived1_CBase2().cbase2()!=4, "MakeConstPtrRefDerived1_CBase2 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived2_CBase1().cbase1y()!=6, "MakeConstPtrRefDerived2_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived2_ABase1().abase1()!=5, "MakeConstPtrRefDerived2_ABase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_ABase1().abase1()!=9, "MakeConstPtrRefDerived3_ABase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_CBase1().cbase1y()!=7, "MakeConstPtrRefDerived3_CBase1 failed");
+    check(multiple_inheritance_shared_ptr.MakeConstPtrRefDerived3_CBase2().cbase2()!=8, "MakeConstPtrRefDerived3_CBase2 failed");
+
     // Return by value (sliced objects)
     check(multiple_inheritance_shared_ptr.MakeValDerived1_CBase1().cbase1y()!=1, "MakeValDerived1_CBase1 failed");
     check(multiple_inheritance_shared_ptr.MakeValDerived1_CBase2().cbase2()!=2, "MakeValDerived1_CBase2 failed");

Examples/test-suite/multiple_inheritance_abstract.i

@@ -22,7 +22,7 @@ namespace Space {
   struct CBase1 {
     virtual void cbase1x() {
       return;
-    } 
+    }
     virtual int cbase1y() {
       return 1;
     }
@@ -306,6 +306,36 @@ namespace Space {
     return d;
   }
 
+  // Return const pointer references
+  CBase1 *const&MakeConstPtrRefDerived1_CBase1() {
+    static CBase1 *d = new Derived1();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived1_CBase2() {
+    static CBase2 *const& d = new Derived1();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived2_CBase1() {
+    static CBase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived2_ABase1() {
+    static ABase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived3_ABase1() {
+    static ABase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived3_CBase1() {
+    static CBase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived3_CBase2() {
+    static CBase2 *const& d = new Derived3();
+    return d;
+  }
+
   // Return by value (sliced objects)
   CBase1 MakeValDerived1_CBase1() {
     return Derived1();

Examples/test-suite/multiple_inheritance_nspace.i

@@ -31,7 +31,7 @@ namespace Space {
   struct CBase1 {
     virtual void cbase1x() {
       return;
-    } 
+    }
     virtual int cbase1y() {
       return 1;
     }
@@ -315,6 +315,36 @@ namespace Space {
     return d;
   }
 
+  // Return const pointer references
+  CBase1 *const&MakeConstPtrRefDerived1_CBase1() {
+    static CBase1 *d = new Derived1();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived1_CBase2() {
+    static CBase2 *const& d = new Derived1();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived2_CBase1() {
+    static CBase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived2_ABase1() {
+    static ABase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived3_ABase1() {
+    static ABase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived3_CBase1() {
+    static CBase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived3_CBase2() {
+    static CBase2 *const& d = new Derived3();
+    return d;
+  }
+
   // Return by value (sliced objects)
   CBase1 MakeValDerived1_CBase1() {
     return Derived1();

Examples/test-suite/multiple_inheritance_shared_ptr.i

@@ -424,6 +424,36 @@ namespace Space {
     return d;
   }
 
+  // Return const pointer references
+  CBase1 *const&MakeConstPtrRefDerived1_CBase1() {
+    static CBase1 *d = new Derived1();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived1_CBase2() {
+    static CBase2 *const& d = new Derived1();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived2_CBase1() {
+    static CBase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived2_ABase1() {
+    static ABase1 *const& d = new Derived2();
+    return d;
+  }
+  ABase1 *const&MakeConstPtrRefDerived3_ABase1() {
+    static ABase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase1 *const&MakeConstPtrRefDerived3_CBase1() {
+    static CBase1 *const& d = new Derived3();
+    return d;
+  }
+  CBase2 *const&MakeConstPtrRefDerived3_CBase2() {
+    static CBase2 *const& d = new Derived3();
+    return d;
+  }
+
   // Return by value (sliced objects)
   CBase1 MakeValDerived1_CBase1() {
     return Derived1();

Lib/java/swiginterface.i

@@ -28,7 +28,7 @@
   }
 %typemap(javaout) CTYPE *const& {
     long cPtr = $jnicall;
-    return (cPtr == 0) ? null : ($javainterfacename)new $javaclassname(cPtr, $owner);
+    return (cPtr == 0) ? null : ($*javainterfacename)new $*javaclassname(cPtr, $owner);
   }
 
 %typemap(javadirectorin) CTYPE "($&javainterfacename)new $&javaclassname($jniinput, true)"