Javascript, Octave, R - Improve exceptions for %catches

and exception specifications for native types.

Now the raised exception contains the string value as the exception
message instead of just the C/C++ type of the exception.

R exceptions were completely swallowed beforehand

CHANGES.current

@@ -7,6 +7,11 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2022-09-17: wsfulton
+            [Javascript, Octave, R] Improve exceptions for %catches and exception
+            specifications for native types. String exception messages are shown as
+            the exception message instead of just the type of the exception.
+
 2022-09-17: wsfulton
             Add missing typecheck typemaps for std::auto_ptr and std::unique_ptr to
             fix overloading when using these types.

Examples/javascript/exception/runme.js

@@ -10,7 +10,7 @@ try{
   if(error == -1) {
     console.log("t.unknown() didn't throw");
   } else {
-    console.log("successfully caught throw in Test::unknown().");
+    console.log("successfully caught throw in Test::unknown() :" + error);
   }
 }
 
@@ -22,7 +22,7 @@ catch(error){
   if(error == -1) {
     console.log("t.simple() did not throw");
   } else {
-    console.log("successfully caught throw in Test::simple().");
+    console.log("successfully caught throw in Test::simple() :" + error);
   }
 }
 
@@ -33,7 +33,7 @@ try{
   if(error == -1) {
     console.log("t.message() did not throw");
   } else {
-    console.log("successfully caught throw in Test::message().");
+    console.log("successfully caught throw in Test::message() :" + error);
   }
 }
     
@@ -45,7 +45,7 @@ catch(error){
   if(error == -1) {
     console.log("t.hosed() did not throw");
   } else {
-    console.log("successfully caught throw in Test::hosed().");
+    console.log("successfully caught throw in Test::hosed() :" + error + " " + error.code + " " + error.msg);
   }
 }
 
@@ -58,7 +58,7 @@ for (var i=1; i<4; i++) {
     if(error == -1) {
       console.log("t.multi(" + i + ") did not throw");
     } else {
-      console.log("successfully caught throw in Test::multi().");
+      console.log("successfully caught throw in Test::multi() :" + error);
     }
   }
-}    
+}

Lib/javascript/jsc/javascriptrun.swg

@@ -7,23 +7,27 @@
 #define SWIG_exception(code, msg) do { SWIG_JSC_exception(context, exception, code, msg); SWIG_fail; } while (0)
 #define SWIG_fail                 goto fail
 
-SWIGRUNTIME void SWIG_Javascript_Raise(JSContextRef context, JSValueRef *exception, const char* type) {
+SWIGRUNTIME void SWIG_Javascript_Raise_ValueRef(JSContextRef context, JSValueRef *exception, JSValueRef valRef) {
-  JSStringRef message = JSStringCreateWithUTF8CString(type);
   JSValueRef error_arguments[1]; 
   JSObjectRef exception_object;
-  JSValueRef exception_value;
-  exception_value = JSValueMakeString(context, message);
   /* Converting the result to an object will let JavascriptCore add 
      "sourceURL" (file) and "line" (number) and "message" to the exception,
      instead of just returning a raw string. This is extremely important for debugging your errors.
      Using JSObjectMakeError is better than JSValueToObject because the latter only populates
      "sourceURL" and "line", but not "message" or any others I don't know about.
    */
-  error_arguments[0] = exception_value;
+  error_arguments[0] = valRef;
   exception_object = JSObjectMakeError(context, 1, error_arguments, NULL);
 
   /* Return the exception_object */
   *exception = exception_object;
+}
+
+SWIGRUNTIME void SWIG_Javascript_Raise(JSContextRef context, JSValueRef *exception, const char* msg) {
+  JSStringRef message = JSStringCreateWithUTF8CString(msg);
+  JSValueRef exception_value = JSValueMakeString(context, message);
+
+  SWIG_Javascript_Raise_ValueRef(context, exception, exception_value);
 
   JSStringRelease(message);
 }

Lib/javascript/jsc/javascripttypemaps.swg

@@ -41,7 +41,7 @@
 #define SWIG_SetConstant(name, obj)
 
 /* raise */
-#define SWIG_Raise(obj, type, desc)  SWIG_Javascript_Raise(context, exception, type)
+#define SWIG_Raise(obj, type, desc)  SWIG_Javascript_Raise_ValueRef(context, exception, obj)
 
 %insert("runtime") %{
 #define SWIG_JSC_FROM_DECL_ARGS(arg1)              (JSContextRef context, arg1)

Lib/javascript/v8/javascriptrun.swg

@@ -96,6 +96,11 @@ SWIGINTERN void SWIG_V8_Raise(const char *msg) {
   SWIGV8_THROW_EXCEPTION(v8::Exception::Error(SWIGV8_STRING_NEW(msg)));
 }
 
+SWIGINTERN void SWIG_V8_Raise(SWIGV8_VALUE obj, const char *msg) {
+  SWIGV8_THROW_EXCEPTION(obj);
+}
+
+
 /*
   Note: There are two contexts for handling errors.
   A static V8ErrorHandler is used in not overloaded methods.

Lib/javascript/v8/javascripttypemaps.swg

@@ -37,7 +37,7 @@
 #define SWIG_SetConstant(name, obj)
 
 /* raise */
-#define SWIG_Raise(obj, type, desc)  SWIG_V8_Raise(type)
+#define SWIG_Raise(obj, type, desc)  SWIG_V8_Raise(obj, type)
 
 /* Include the unified typemap library */
 %include <typemaps/swigtypemaps.swg>

Lib/octave/octtypemaps.swg

@@ -32,7 +32,7 @@
 #define SWIG_SetConstant(name, obj)     SWIG_Octave_SetConstant(module_ns,name,obj) 
 
 // raise
-#define SWIG_Octave_Raise(OBJ, TYPE, DESC) error("C++ side threw an exception of type " TYPE)
+#define SWIG_Octave_Raise(OBJ, TYPE, DESC) error(OBJ.is_string() ? OBJ.string_value().c_str() : "C++ side threw an exception of type " TYPE)
 #define SWIG_Raise(obj, type, desc)     SWIG_Octave_Raise(obj, type, desc)
 
 // Include the unified typemap library

Lib/r/r.swg

@@ -26,9 +26,13 @@ SWIGEXPORT void SWIG_init(void) {
    assign(name, _obj);
 %end_block %enddef
 
-%define %raise(obj,type,desc) 
+%runtime %{
-return R_NilValue;
+void SWIG_R_Raise(SEXP obj, const char *msg) {
-%enddef
+  Rf_error(Rf_isString(obj) ? STRING_VALUE(obj) : msg);
+}
+%}
+
+#define %raise(OBJ, TYPE, DESC) SWIG_R_Raise(OBJ, "C/C++ exception of type " TYPE); return R_NilValue
 
 %insert("sinit") "srun.swg"