The kwargs feature no longer turns on compactdefaultargs for languages that don't support kwargs.

Affects all languages except Python and Ruby.

Closes #242

CHANGES.current

@@ -5,6 +5,13 @@ See the RELEASENOTES file for a summary of changes in each release.
 Version 3.0.3 (in progress)
 ===========================
 
+2014-10-21: wsfulton
+            Fix issue #242 - Use of the "kwargs" feature no longer automatically turns on the
+            "compactdefaultargs" feature if the target language does not support kwargs.
+            Only Java and Python support kwargs, so this affects all the other languages.
+
+            *** POTENTIAL INCOMPATIBILITY  ***
+
 2014-10-10: diorcety
             [Python] Patch #232 Fix property access using directors
 

Doc/Manual/SWIGPlus.html

@@ -1191,8 +1191,10 @@ values have to be public).
 </p>
 
 <p>
-This feature is automatically turned on when wrapping <a href="SWIG.html#SWIG_default_args">C code with default arguments</a>
-and whenever keyword arguments (kwargs) are specified for either C or C++ code.
+The <tt>compactdefaultargs</tt> feature is automatically turned on when wrapping <a href="SWIG.html#SWIG_default_args">C code with default arguments</a>.
+Some target languages will also automatically turn on this feature
+if the keyword arguments feature (kwargs) is specified for either C or C++ functions, and the target language supports kwargs,
+the <tt>compactdefaultargs</tt> feature is also automatically turned on.
 Keyword arguments are a language feature of some scripting languages, for example Ruby and Python.
 SWIG is unable to support kwargs when wrapping overloaded methods, so the default approach cannot be used.
 </p>

Examples/test-suite/common.mk

@@ -249,6 +249,7 @@ CPP_TEST_CASES += \
 	insert_directive \
 	keyword_rename \
 	kind \
+	kwargs_feature \
 	langobj \
 	li_attribute \
 	li_attribute_template \

Examples/test-suite/java/kwargs_feature_runme.java

@@ -0,0 +1,23 @@
+import kwargs_feature.*;
+
+public class kwargs_feature_runme {
+
+  static {
+    try {
+	System.loadLibrary("kwargs_feature");
+    } 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[]) {
+    // Check normal overloading still works (no compactdefaultargs) if the kwargs feature is used,
+    // as the kwargs feature is not supported
+    Foo f = new Foo(99);
+    if (f.foo() != 1)
+      throw new RuntimeException("It went wrong");
+    if (Foo.statfoo(2) != 2)
+      throw new RuntimeException("It went wrong");
+  }
+}

Examples/test-suite/kwargs_feature.i

@@ -1,7 +1,7 @@
 %module kwargs_feature
 
 %nocopyctor;
-%kwargs;
+%feature("kwargs");
 
 %rename(myDel) del;
 %inline 
@@ -35,9 +35,7 @@
 
     virtual ~Foo() {
     }
-    
   };
-
 %}
 
 
@@ -64,8 +62,7 @@
 
 // Functions
 %inline %{
-  int foo(int a = 1, int b = 0) {return a + b; }
-
+  int foo_fn(int a = 1, int b = 0) {return a + b; }
   
   template<typename T> T templatedfunction(T a = 1, T b = 0) { return a + b; }
 %}
@@ -73,10 +70,8 @@
 %template(templatedfunction) templatedfunction<int>;
 
 
-// Deafult args with references
-%inline
-%{
-
+// Default args with references
+%inline %{
   typedef int size_type;
   
   struct Hello 
@@ -84,13 +79,10 @@
     static const size_type hello = 3;
   };
   
-  
-  
   int rfoo( const size_type& x = Hello::hello, const Hello& y = Hello() )
   {
     return x;
   }
-  
 %}
 %{
   const int Hello::hello;
@@ -104,9 +96,7 @@
 
   int foo_kw(int from = 1, int except = 2) {return from + except; }
 
-
   int foo_nu(int from = 1, int = 0) {return from; }
 
   int foo_mm(int min = 1, int max = 2) {return min + max; }
-
 %}

Examples/test-suite/python/Makefile.in

@@ -39,7 +39,6 @@ CPP_TEST_CASES += \
 	inout \
 	inplaceadd \
 	input \
-	kwargs_feature \
 	li_cstring \
 	li_cwstring \
 	li_factory \

Examples/test-suite/python/kwargs_feature_runme.py

@@ -44,10 +44,10 @@ if BarInt_sbar(b=2) != 3:
 if templatedfunction(b=2) != 3:
   raise RuntimeError
 
-if foo(a=1,b=2) != 3:
+if foo_fn(a=1,b=2) != 3:
   raise RuntimeError
 
-if foo(b=2) != 3:
+if foo_fn(b=2) != 3:
   raise RuntimeError
 
 

Examples/test-suite/ruby/Makefile.in

@@ -11,7 +11,6 @@ top_srcdir   = @top_srcdir@
 top_builddir = @top_builddir@
 
 CPP_TEST_CASES = \
-	kwargs_feature \
 	li_cdata \
 	li_cstring \
 	li_factory \

Source/CParse/parser.y

@@ -59,6 +59,7 @@ static int      compact_default_args = 0;
 static int      template_reduce = 0;
 static int      cparse_externc = 0;
 int		ignore_nested_classes = 0;
+int		kwargs_supported = 0;
 /* -----------------------------------------------------------------------------
  *                            Assist Functions
  * ----------------------------------------------------------------------------- */
@@ -1177,7 +1178,7 @@ static void default_arguments(Node *n) {
     if (compact_default_args 
 	|| is_cfunction(function) 
 	|| GetFlag(function,"feature:compactdefaultargs") 
-	|| GetFlag(function,"feature:kwargs")) {
+	|| (GetFlag(function,"feature:kwargs") && kwargs_supported)) {
       ParmList *p = Getattr(function,"parms");
       if (p) 
         Setattr(p,"compactdefargs", "1"); /* mark parameters for special handling */

Source/Modules/lang.cxx

@@ -3525,6 +3525,14 @@ Language::NestedClassSupport Language::nestedClassesSupport() const {
   return NCS_Unknown;
 }
 
+/* -----------------------------------------------------------------------------
+ * Language::kwargsSupport()
+ * ----------------------------------------------------------------------------- */
+
+bool Language::kwargsSupport() const {
+  return false;
+}
+
 /* -----------------------------------------------------------------------------
  * Language::is_wrapping_class()
  * ----------------------------------------------------------------------------- */

Source/Modules/main.cxx

@@ -50,6 +50,7 @@ int SwigRuntime = 0;		// 0 = no option, 1 = -runtime, 2 = -noruntime
 extern "C" {
   extern String *ModuleName;
   extern int ignore_nested_classes;
+  extern int kwargs_supported;
 }
 
 /* usage string split into multiple parts otherwise string is too big for some compilers */
@@ -904,6 +905,8 @@ int SWIG_main(int argc, char *argv[], Language *l) {
   // Inform the parser if the nested classes should be ignored unless explicitly told otherwise via feature:flatnested
   ignore_nested_classes = l->nestedClassesSupport() == Language::NCS_Unknown ? 1 : 0;
 
+  kwargs_supported = l->kwargsSupport() ? 1 : 0;
+
   // Create Library search directories
 
   // Check for SWIG_LIB environment variable

Source/Modules/python.cxx

@@ -4785,6 +4785,13 @@ public:
     return NewString("swigpyrun.h");
   }
 
+  /*----------------------------------------------------------------------
+   * kwargsSupport()
+   *--------------------------------------------------------------------*/
+
+  bool kwargsSupport() const {
+    return true;
+  }
 };
 
 /* ---------------------------------------------------------------

Source/Modules/ruby.cxx

@@ -3426,6 +3426,14 @@ public:
   String *defaultExternalRuntimeFilename() {
     return NewString("swigrubyrun.h");
   }
+
+  /*----------------------------------------------------------------------
+   * kwargsSupport()
+   *--------------------------------------------------------------------*/
+
+  bool kwargsSupport() const {
+    return true;
+  }
 };				/* class RUBY */
 
 /* -----------------------------------------------------------------------------

Source/Modules/swigmod.h

@@ -315,6 +315,9 @@ public:
   */
   virtual NestedClassSupport nestedClassesSupport() const;
 
+  /* Returns true if the target language supports key word arguments (kwargs) */
+  virtual bool kwargsSupport() const;
+
 protected:
   /* Identifies if a protected members that are generated when the allprotected option is used.
      This does not include protected virtual methods as they are turned on with the dirprot option. */