%template scope enforcement and class definition fixes

The scoping rules around %template have been specified and enforced.
The %template directive for a class template is the equivalent to an
explicit instantiation of a C++ class template. The scope for a valid
%template instantiation is now the same as the scope required for a
valid explicit instantiation of a C++ template. A definition of the
template for the explicit instantiation must be in scope where the
instantiation is declared and must not be enclosed within a different
namespace.

For example, a few %template and explicit instantiations of std::vector
are shown below:

  // valid
  namespace std {
    %template(vin) vector<int>;
    template class vector<int>;
  }

  // valid
  using namespace std;
  %template(vin) vector<int>;
  template class vector<int>;

  // valid
  using std::vector;
  %template(vin) vector<int>;
  template class vector<int>;

  // ill-formed
  namespace unrelated {
    using std::vector;
    %template(vin) vector<int>;
    template class vector<int>;
  }

  // ill-formed
  namespace unrelated {
    using namespace std;
    %template(vin) vector<int>;
    template class vector<int>;
  }

  // ill-formed
  namespace unrelated {
    namespace std {
      %template(vin) vector<int>;
      template class vector<int>;
    }
  }

  // ill-formed
  namespace unrelated {
    %template(vin) std::vector<int>;
    template class std::vector<int>;
  }

When the scope is incorrect, an error now occurs such as:

cpp_template_scope.i:34: Error: 'vector' resolves to 'std::vector' and
was incorrectly instantiated in scope 'unrelated' instead of within scope 'std'.

Previously SWIG accepted the ill-formed examples above but this led to
numerous subtle template scope problems especially in the presence of
using declarations and using directives as well as with %feature and %typemap.

Actually, a valid instantiation is one which conforms to the C++03
standard as C++11 made a change to disallow using declarations and
using directives to find a template.

  // valid C++03, ill-formed C++11
  using std::vector;
  template class vector<int>;

Similar fixes for defining classes using forward class references have
also been put in place. For example:

namespace Space1 {
  struct A;
}
namespace Space2 {
  struct Space1::A {
    void x();
  }
}

will now error out with:

cpp_class_definition.i:5: Error: 'Space1::A' resolves to 'Space1::A' and
was incorrectly instantiated in scope 'Space2' instead of within scope 'Space1'.

Examples/test-suite/class_scope_namespace.i

@@ -0,0 +1,153 @@
+// Test a mix of forward class declarations, class definitions, using declarations and using directives.
+
+%module class_scope_namespace
+
+%warnfilter(SWIGWARN_PARSE_NAMED_NESTED_CLASS) H::HH;
+%warnfilter(SWIGWARN_PARSE_NAMED_NESTED_CLASS) Space8::I::II;
+
+%inline %{
+struct A;
+namespace Space1 {
+  namespace SubSpace1 {
+    struct A {
+      void aa(Space1::SubSpace1::A, SubSpace1::A, A) {}
+    };
+    void aaa(Space1::SubSpace1::A, SubSpace1::A, A) {}
+  }
+}
+
+namespace Space2 {
+  struct B;
+}
+using Space2::B;
+struct B {
+  void bb(Space2::B, B) {}
+};
+void bbb(Space2::B, B) {}
+
+namespace Space3 {
+  namespace SubSpace3 {
+    struct C;
+    struct D;
+  }
+}
+struct C;
+struct D;
+namespace Space3 {
+  struct C;
+  struct SubSpace3::C {
+    void cc(Space3::SubSpace3::C, SubSpace3::C) {}
+  };
+  using SubSpace3::D;
+  struct SubSpace3::D {
+    void dd(Space3::SubSpace3::D, SubSpace3::D, D) {}
+  };
+  void ccc(Space3::SubSpace3::C, SubSpace3::C) {}
+  void ddd(Space3::SubSpace3::D, SubSpace3::D, D) {}
+}
+
+namespace Space4 {
+  namespace SubSpace4 {
+    struct E;
+  }
+}
+using namespace Space4;
+using SubSpace4::E;
+// Was added to incorrect namespace in swig-3.0.12
+struct SubSpace4::E {
+  void ee(Space4::SubSpace4::E, SubSpace4::E, E) {}
+};
+void eee(Space4::SubSpace4::E, SubSpace4::E, E) {}
+
+namespace Space5 {
+  namespace SubSpace5 {
+    namespace SubSubSpace5 {
+      struct F;
+    }
+  }
+}
+namespace Space5 {
+  using namespace SubSpace5;
+  using SubSubSpace5::F;
+  // Was added to incorrect namespace in swig-3.0.12
+  struct SubSubSpace5::F {
+    void ff(Space5::SubSpace5::SubSubSpace5::F, SubSpace5::SubSubSpace5::F, SubSubSpace5::F, F) {}
+  };
+// needs fixing
+  void fff(Space5::SubSpace5::SubSubSpace5::F, SubSpace5::SubSubSpace5::F, /*SubSubSpace5::F,*/ F) {}
+}
+
+namespace Space6 {
+  struct G;
+  namespace SubSpace6 {
+    struct G;
+  }
+}
+namespace Space6 {
+  struct SubSpace6::G {
+    void gg(Space6::SubSpace6::G, SubSpace6::G) {}
+  };
+  void ggg(Space6::SubSpace6::G, SubSpace6::G) {}
+}
+
+struct HH;
+struct H {
+  struct HH {
+    void hh(H::HH) {}
+  };
+};
+void hhh(H::HH) {}
+
+namespace Space8 {
+  struct II;
+  struct I {
+    struct II {
+      void ii(Space8::I::II, I::II) {}
+    };
+  };
+  void iii(Space8::I::II, I::II) {}
+}
+
+struct J;
+namespace Space9 {
+  namespace SubSpace9 {
+    struct J {
+      void jj(Space9::SubSpace9::J, SubSpace9::J, J) {}
+    };
+    void jjj(Space9::SubSpace9::J, SubSpace9::J, J) {}
+  }
+}
+
+namespace Space10 {
+  struct K;
+}
+namespace Space10 {
+  namespace SubSpace10 {
+    struct K {
+      void kk(Space10::SubSpace10::K, SubSpace10::K, K) {}
+    };
+    void kkk(Space10::SubSpace10::K, SubSpace10::K, K) {}
+  }
+}
+
+namespace OtherSpace {
+  struct L;
+  struct M;
+}
+using OtherSpace::L;
+namespace Space11 {
+  using OtherSpace::M;
+  namespace SubSpace11 {
+    struct L {
+      void ll(Space11::SubSpace11::L, SubSpace11::L, L) {}
+    };
+    void lll(Space11::SubSpace11::L, SubSpace11::L, L) {}
+    struct M {
+      void mm(Space11::SubSpace11::M, SubSpace11::M, M) {}
+    };
+    void mmm(Space11::SubSpace11::M, SubSpace11::M, M) {}
+  }
+}
+
+%}
+

Examples/test-suite/common.mk

@@ -136,6 +136,7 @@ CPP_TEST_CASES += \
 	char_binary \
 	char_strings \
 	chartest \
+	class_scope_namespace \
 	class_forward \
 	class_ignore \
 	class_scope_weird \

Examples/test-suite/errors/cpp_class_definition.i

@@ -0,0 +1,26 @@
+%module xxx
+
+// This should error but doesn't
+#if 0
+namespace OtherSpace {
+  struct L;
+}
+namespace Space11 {
+  namespace SubSpace11 {
+    using OtherSpace::L;
+    struct L {
+      void ll();
+    };
+  }
+}
+#endif
+
+namespace Space1 {
+  struct A;
+}
+namespace Space2 {
+  struct Space1::A {
+    void x();
+  };
+}
+

Examples/test-suite/errors/cpp_class_definition.stderr

@@ -0,0 +1 @@
+cpp_class_definition.i:22: Error: 'Space1::A' resolves to 'Space1::A' and was incorrectly instantiated in scope 'Space2' instead of within scope 'Space1'.

Examples/test-suite/errors/cpp_namespace_template_bad.i

@@ -0,0 +1,40 @@
+%module namespace_template
+
+namespace test {
+  template<typename T> T max(T a, T b) { return (a > b) ? a : b; }
+  template<typename T> class vector { 
+  public:
+    vector() { }
+    ~vector() { }
+  }; 
+}
+
+namespace test2 {
+  using namespace test;
+  %template(maxshort) max<short>;
+  %template(vectorshort) vector<short>;
+}
+
+namespace test3 {
+  using test::max;
+  using test::vector;
+  %template(maxlong) max<long>;
+  %template(vectorlong) vector<long>;
+}
+
+namespace test4 {
+  using namespace test;
+  typedef int Integer;
+}
+
+namespace test4 {
+  %template(maxInteger) max<Integer>;
+  %template(vectorInteger) vector<Integer>;
+}
+
+using namespace test;
+namespace test5 {
+  %template(maxdouble) max<double>;
+  %template(vectordouble) vector<double>;
+}
+

Examples/test-suite/errors/cpp_namespace_template_bad.stderr

@@ -0,0 +1,9 @@
+cpp_namespace_template_bad.i:14: Error: 'max' resolves to 'test::max' and was incorrectly instantiated in scope 'test2' instead of within scope 'test'.
+cpp_namespace_template_bad.i:15: Error: 'vector' resolves to 'test::vector' and was incorrectly instantiated in scope 'test2' instead of within scope 'test'.
+cpp_namespace_template_bad.i:21: Error: 'max' resolves to 'test::max' and was incorrectly instantiated in scope 'test3' instead of within scope 'test'.
+cpp_namespace_template_bad.i:22: Error: 'vector' resolves to 'test::vector' and was incorrectly instantiated in scope 'test3' instead of within scope 'test'.
+cpp_namespace_template_bad.i:31: Error: 'max' resolves to 'test::max' and was incorrectly instantiated in scope 'test4' instead of within scope 'test'.
+cpp_namespace_template_bad.i:32: Error: 'vector' resolves to 'test::vector' and was incorrectly instantiated in scope 'test4' instead of within scope 'test'.
+cpp_namespace_template_bad.i:37: Error: 'max' resolves to 'test::max' and was incorrectly instantiated in scope 'test5' instead of within scope 'test'.
+cpp_namespace_template_bad.i:37: Error: Template 'max' undefined.
+cpp_namespace_template_bad.i:38: Error: 'vector' resolves to 'test::vector' and was incorrectly instantiated in scope 'test5' instead of within scope 'test'.

Examples/test-suite/errors/cpp_nested_template.stderr

@@ -1,2 +1,4 @@
+cpp_nested_template.i:9: Error: 'Temply' resolves to '::Temply' and was incorrectly instantiated in scope 'A' instead of within scope ''.
 cpp_nested_template.i:9: Warning 324: Named nested template instantiations not supported. Processing as if no name was given to %template().
+cpp_nested_template.i:18: Error: 'Temply' resolves to '::Temply' and was incorrectly instantiated in scope 'B' instead of within scope ''.
 cpp_nested_template.i:18: Warning 324: Named nested template instantiations not supported. Processing as if no name was given to %template().

Examples/test-suite/errors/cpp_template_scope.i

@@ -0,0 +1,57 @@
+%module xxx
+
+namespace std {
+  template<typename T> class vector {};
+}
+
+struct S1 {};
+struct S2 {};
+struct S3 {};
+struct S4 {};
+struct S5 {};
+struct S6 {};
+struct S7 {};
+
+// valid
+namespace std {
+  %template(vi1) vector<S1>;
+  template class vector<S1>;
+}
+
+// valid
+using namespace std;
+%template(vi2) vector<S2>;
+template class vector<S2>;
+
+// valid
+using std::vector;
+%template(vi3) vector<S3>;
+template class vector<S3>;
+
+// ill-formed
+namespace unrelated {
+  using std::vector;
+  %template(vi4) vector<S4>;
+  template class vector<S4>;
+}
+
+// ill-formed
+namespace unrelated {
+  using namespace std;
+  %template(vi5) vector<S5>;
+  template class vector<S5>;
+}
+
+// ill-formed
+namespace unrelated {
+  namespace std {
+    %template(vi6) vector<S6>;
+    template class vector<S6>;
+  }
+}
+
+// ill-formed
+namespace unrelated {
+  %template(vi7) std::vector<S7>;
+  template class std::vector<S7>;
+}

Examples/test-suite/errors/cpp_template_scope.stderr

@@ -0,0 +1,11 @@
+cpp_template_scope.i:18: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:24: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:29: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:34: Error: 'vector' resolves to 'std::vector' and was incorrectly instantiated in scope 'unrelated' instead of within scope 'std'.
+cpp_template_scope.i:35: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:41: Error: 'vector' resolves to 'std::vector' and was incorrectly instantiated in scope 'unrelated' instead of within scope 'std'.
+cpp_template_scope.i:42: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:48: Error: 'vector' resolves to 'std::vector' and was incorrectly instantiated in scope 'unrelated::std' instead of within scope 'std'.
+cpp_template_scope.i:49: Warning 320: Explicit template instantiation ignored.
+cpp_template_scope.i:55: Error: 'std::vector' resolves to 'std::vector' and was incorrectly instantiated in scope 'unrelated' instead of within scope 'std'.
+cpp_template_scope.i:56: Warning 320: Explicit template instantiation ignored.

Examples/test-suite/java/class_scope_namespace_runme.java

@@ -0,0 +1,59 @@
+
+import class_scope_namespace.*;
+
+public class class_scope_namespace_runme {
+
+  static {
+    try {
+      System.loadLibrary("class_scope_namespace");
+    } catch (UnsatisfiedLinkError e) {
+      System.err.println("Native code library failed to load. See the chapter on Dynamic Linking Problems in the SWIG Java documentation for help.\n" + e);
+      System.exit(1);
+    }
+  }
+
+  public static void main(String argv[]) 
+  {
+    A a = new A();
+    B b = new B();
+    C c = new C();
+    D d = new D();
+    E e = new E();
+    F f = new F();
+    G g = new G();
+    H.HH h = new H.HH();
+    I.II i = new I.II();
+    J j = new J();
+    K k = new K();
+    L l = new L();
+    M m = new M();
+
+    a.aa(a, a, a);
+    b.bb(b, b);
+    c.cc(c, c);
+    d.dd(d, d, d);
+    e.ee(e, e, e);
+    f.ff(f, f, f, f);
+    g.gg(g, g);
+    h.hh(h);
+    i.ii(i, i);
+    j.jj(j, j, j);
+    k.kk(k, k, k);
+    l.ll(l, l, l);
+    m.mm(m, m, m);
+
+    class_scope_namespace.aaa(a, a, a);
+    class_scope_namespace.bbb(b, b);
+    class_scope_namespace.ccc(c, c);
+    class_scope_namespace.ddd(d, d, d);
+    class_scope_namespace.eee(e, e, e);
+    class_scope_namespace.fff(f, f, f);
+    class_scope_namespace.ggg(g, g);
+    class_scope_namespace.hhh(h);
+    class_scope_namespace.iii(i, i);
+    class_scope_namespace.jjj(j, j, j);
+    class_scope_namespace.kkk(k, k, k);
+    class_scope_namespace.lll(l, l, l);
+    class_scope_namespace.mmm(m, m, m);
+  }
+}

Examples/test-suite/java/namespace_template_runme.java

@@ -0,0 +1,32 @@
+
+import namespace_template.*;
+
+public class namespace_template_runme {
+
+  static {
+    try {
+      System.loadLibrary("namespace_template");
+    } catch (UnsatisfiedLinkError e) {
+      System.err.println("Native code library failed to load. See the chapter on Dynamic Linking Problems in the SWIG Java documentation for help.\n" + e);
+      System.exit(1);
+    }
+  }
+
+  public static void main(String argv[]) {
+    vectorchar vc = new vectorchar();
+    vectorshort vs = new vectorshort();
+    vectorint vi = new vectorint();
+    vectorlong vl = new vectorlong();
+
+    vc.blah((char)10);
+    vs.blah((short)10);
+    vi.blah(10);
+    vl.blah(10);
+
+    vc.vectoruse(vc, vc);
+    vs.vectoruse(vs, vs);
+    vi.vectoruse(vi, vi);
+    vl.vectoruse(vl, vl);
+  }
+}
+

Examples/test-suite/namespace_template.i

@@ -2,10 +2,10 @@
 
 %module namespace_template
 
-%warnfilter(SWIGWARN_RUBY_WRONG_NAME) vector<int>;            /* Ruby, wrong class name */
-%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test2::vector<short>;   /* Ruby, wrong class name */
-%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test3::vector<long>;    /* Ruby, wrong class name */
-%warnfilter(SWIGWARN_RUBY_WRONG_NAME) vector<test4::Integer>; /* Ruby, wrong class name */
+%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test::vector<int>;        /* Ruby, wrong class name */
+%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test::vector<short>;      /* Ruby, wrong class name */
+%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test::vector<long>;       /* Ruby, wrong class name */
+%warnfilter(SWIGWARN_RUBY_WRONG_NAME) test::vector<test::Char>; /* Ruby, wrong class name */
 
 %{
 #ifdef max
@@ -23,20 +23,9 @@ namespace test {
            char * blah(T x) {
               return (char *) "vector::blah";
            }
+           void vectoruse(vector<T> a, test::vector<T> b) {}
    }; 
 }
-
-namespace test2 {
-   using namespace test;
-}
-
-namespace test3 {
-   using test::max;
-   using test::vector;
-}
-
-using namespace test2;
-namespace T4 = test;
 %}
 
 namespace test {
@@ -48,6 +37,7 @@ namespace test {
            char * blah(T x) {
               return (char *) "vector::blah";
            }
+           void vectoruse(vector<T> a, test::vector<T> b) {}
    }; 
 }
 
@@ -55,30 +45,26 @@ using namespace test;
 %template(maxint) max<int>;
 %template(vectorint) vector<int>;
 
-namespace test2 {
-   using namespace test;
+namespace test {
    %template(maxshort) max<short>;
    %template(vectorshort) vector<short>;
 }
 
-namespace test3 {
-   using test::max;
-   using test::vector;
+namespace test {
    %template(maxlong) max<long>;
    %template(vectorlong) vector<long>;
 }
 
 %inline %{
 
-namespace test4 {
-   using namespace test;
-   typedef int Integer;
+namespace test {
+   typedef char Char;
 }
 
 %}
 
-namespace test4 {
-   %template(maxInteger) max<Integer>;
-   %template(vectorInteger) vector<Integer>;
+namespace test {
+   %template(maxchar) max<Char>;
+   %template(vectorchar) vector<Char>;
 }
 

Examples/test-suite/smart_pointer_namespace2.i

@@ -49,11 +49,6 @@ namespace one
     };
 }
 
-%define PTR_DEF(o)
-typedef one::Ptr<o> o ## _ptr;
-%template(o ## _ptr) one::Ptr<o>;
-%enddef
-
 namespace one
 {
     class Obj1
@@ -63,7 +58,8 @@ namespace one
         void donothing() {}
     };
 
-    PTR_DEF(Obj1)
+    typedef one::Ptr<Obj1> Obj1_ptr;
+    %template(Obj1_ptr) one::Ptr<Obj1>;
 }
 
 namespace two
@@ -75,6 +71,9 @@ namespace two
         void donothing() {}
     };
 
-    PTR_DEF(Obj2)
+    typedef one::Ptr<Obj2> Obj2_ptr;
 }
 
+using two::Obj2;
+%template(Obj2_ptr) one::Ptr<Obj2>;
+

Examples/test-suite/template_nested_typemaps.i

@@ -1,25 +1,30 @@
-#pragma SWIG nowarn=SWIGWARN_PARSE_NESTED_TEMPLATE
-
 %module template_nested_typemaps
 
-// Testing that the typemaps invoked within a class via %template are picked up by appropriate methods
+#pragma SWIG nowarn=SWIGWARN_PARSE_NAMED_NESTED_CLASS
 
-template <typename T> struct Typemap {
-  %typemap(in) T {
-    $1 = -99;
-  }
-};
-template <> struct Typemap<short> { // Note explicit specialization
-  %typemap(in) short {
-    $1 = -77;
-  }
-};
+// Testing that the typemaps invoked within a class via %template are picked up by appropriate methods
+// Only for languages that support nested classes
 
 %inline %{
 int globalInt1(int s) { return s; }
 short globalShort1(short s) { return s; }
 
 template <typename T> struct Breeze {
+  template <typename TMT> struct Typemap {
+#ifdef SWIG
+    %typemap(in) TMT {
+      $1 = -99;
+    }
+#endif
+  };
+  template <typename TMT> struct TypemapShort {
+#ifdef SWIG
+    %typemap(in) short {
+      $1 = -77;
+    }
+#endif
+  };
+
   int methodInt1(int s) { return s; }
 #if defined(SWIG)
   %template() Typemap<int>;
@@ -29,7 +34,7 @@ template <typename T> struct Breeze {
 
   short methodShort1(short s) { return s; }
 #if defined(SWIG)
-  %template(TypemapShort) Typemap<short>; // should issue warning SWIGWARN_PARSE_NESTED_TEMPLATE
+  %template() TypemapShort<short>;
 #endif
   short methodShort2(short s) { return s; } // should pick up the typemap within Typemap<short>
 };

Examples/test-suite/template_partial_specialization.i

@@ -32,7 +32,7 @@ namespace One {
 %template(H) One::OneParm<int **>;
 
 // %template scope explicit specializations
-namespace ONE {
+namespace One {
   %template(I) One::OneParm<float>;
   %template(J) ::One::OneParm<float *>;
 }
@@ -42,7 +42,7 @@ namespace One {
 }
 
 // %template scope partial specializations
-namespace ONE {
+namespace One {
   %template(BB) One::OneParm<bool *>;
   %template(BBB) ::One::OneParm<char *>;
 }

Examples/test-suite/template_partial_specialization_typedef.i

@@ -59,7 +59,7 @@ namespace One {
 %template(H) One::OneParm<TypeDef::IntPtrPtr>;
 
 // %template scope explicit specializations
-namespace ONE {
+namespace One {
   %template(I) One::OneParm<TypeDef::Float>;
   %template(J) ::One::OneParm<TypeDef::FloatPtr>;
 }
@@ -69,7 +69,7 @@ namespace One {
 }
 
 // %template scope partial specializations
-namespace ONE {
+namespace One {
   %template(BB) One::OneParm<TypeDef::BoolPtr>;
   %template(BBB) ::One::OneParm<TypeDef::CharPtr>;
 }