Changes to use common DirectorException class

Add director.swg for Go as was completely absent.
This is just the start of a common exception handling approach to directors.
An exception thrown in a Java director method will be propogated back to
Java via a C++ DirectorException.
DirectorException throws typemap for Java is fully working, all other languages need work.
DirectorException throws typemap for Perl added just to fix compilation errors.
Add director_exception_catches test.

Examples/test-suite/common.mk

@@ -181,6 +181,7 @@ CPP_TEST_CASES += \
 	director_detect \
 	director_enum \
 	director_exception \
+	director_exception_catches \
 	director_extend \
 	director_finalizer \
 	director_frob \

Examples/test-suite/director_exception_catches.i

@@ -0,0 +1,25 @@
+%module(directors="1") director_exception_catches
+
+%include <std_string.i>
+%feature("director") BaseClass;
+
+%{
+// define dummy director exception classes to prevent spurious errors 
+// in target languages that do not support directors.
+
+#ifndef SWIG_DIRECTORS
+namespace Swig {
+  class DirectorException {};
+}
+#endif /* !SWIG_DIRECTORS */
+%}
+
+%catches(Swig::DirectorException) BaseClass::call_description;
+
+%inline %{
+struct BaseClass {
+  virtual std::string description() const = 0;
+  static std::string call_description(BaseClass& bc) { return bc.description(); }
+  virtual ~BaseClass() {}
+};
+%}

Examples/test-suite/java/director_exception_catches_runme.java

@@ -0,0 +1,35 @@
+
+import director_exception_catches.*;
+
+public class director_exception_catches_runme {
+
+  static {
+    try {
+      System.loadLibrary("director_exception_catches");
+    } 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[]) {
+
+    BaseClass b = new director_exception_catches_MyClass();
+
+    try {
+      String s = BaseClass.call_description(b);
+      throw new RuntimeException("Failed to catch exception");
+    } catch (NullPointerException e) {
+      if (!e.getMessage().startsWith("Testing exception thrown in BaseClass.description"))
+        throw new RuntimeException("Unexpected exception message: " + e.getMessage());
+    }
+  }
+}
+
+class director_exception_catches_MyClass extends BaseClass {
+  @Override
+  public String description() {
+    throw new NullPointerException("Testing exception thrown in BaseClass.description");
+  }
+}
+

Lib/go/director.swg

@@ -0,0 +1,15 @@
+/* -----------------------------------------------------------------------------
+ * director.swg
+ *
+ * This file contains support for director classes so that Go proxy
+ * methods can be called from C++.
+ * ----------------------------------------------------------------------------- */
+
+#include <exception>
+
+namespace Swig {
+
+  class DirectorException : public std::exception {
+  };
+}
+

Lib/java/java.swg

@@ -1051,6 +1051,10 @@ Swig::LocalRefGuard $1_refguard(jenv, $input); }
 %{ SWIG_JavaThrowException(jenv, SWIG_JavaRuntimeException, $1);
    return $null; %}
 
+// For directors to raise/throw the original Java exception
+%typemap(throws) Swig::DirectorException
+%{  $1.raiseJavaException(jenv);
+    return $null; %}
 
 /* Typemaps for code generation in proxy classes and Java type wrapper classes */
 

Lib/octave/director.swg

@@ -46,7 +46,22 @@ namespace Swig {
     }
   };
 
-  struct DirectorTypeMismatchException {
+  // Base class for director exceptions.
+  class DirectorException : public std::exception {
+  public:
+    static void raise(const char *msg) {
+      // ... todo
+      throw(DirectorException());
+    }
+
+    static void raise(const octave_value &ov, const char *msg) {
+      // ... todo
+      raise(msg);
+    }
+  };
+
+  class DirectorTypeMismatchException : public DirectorException {
+  public:
     static void raise(const char *msg) {
       // ... todo
       throw(DirectorTypeMismatchException());
@@ -58,7 +73,8 @@ namespace Swig {
     }
   };
 
-  struct DirectorPureVirtualException {
+  class DirectorPureVirtualException : public DirectorException {
+  public:
     static void raise(const char *msg) {
       // ... todo
       throw(DirectorPureVirtualException());

Lib/perl5/perltypemaps.swg

@@ -71,6 +71,10 @@
 /* raise exception */
 %define %raise(obj, type, desc) sv_setsv(get_sv("@", GV_ADD), obj); SWIG_fail %enddef
 
+/* For directors to raise/throw the original exception */
+%typemap(throws) Swig::DirectorException
+%{ sv_setsv(ERRSV, $1.getNative()); SWIG_fail; %}
+
 /* Include the unified typemap library */
 %include <typemaps/swigtypemaps.swg>
 

Source/Modules/go.cxx

@@ -615,6 +615,12 @@ private:
 
     Language::top(n);
 
+    if (directorsEnabled()) {
+      // Insert director runtime into the f_runtime file (make it occur before %header section)
+      Swig_insert_file("director_common.swg", f_c_runtime);
+      Swig_insert_file("director.swg", f_c_runtime);
+    }
+
     Delete(go_imports);
 
     // Write out definitions for the types not defined by SWIG.