update swig

swmm-toolkit/build-requirements.txt

@@ -5,4 +5,4 @@ setuptools
 wheel
 scikit-build
 cmake
-swig == 4.0.2
+swig

swmm-toolkit/pyproject.toml

@@ -4,7 +4,7 @@ requires = [
     "setuptools>=42",
     "scikit-build>=0.13",
     "cmake>=3.21",
-    "swig==4.0.2",
-    "ninja==1.11.1 ; sys_platform == 'darwin'"
+    "swig",
+    "ninja==1.11.1 ; sys_platform == 'darwin'",
 ]
-build-backend = "setuptools.build_meta"
+build-backend = "setuptools.build_meta"

swmm-toolkit/src/swmm/toolkit/output.i

@@ -12,7 +12,6 @@
 %include "typemaps.i"
 %include "cstring.i"
 
-
 /* Docstrings for module */
 %include "output_docs.i"
 
@@ -28,6 +27,8 @@
 //%rename("%(regex:/^\w+_([a-zA-Z]+)/\L\\1/)s") "";
 %include "output_rename.i"
 
+/* SWIG Override headers*/
+%include "swig_headers.i"
 
 /* MARK FUNCTIONS FOR ALLOCATING AND DEALLOCATING HANDLES */
 %newobject SMO_init;
@@ -77,7 +78,7 @@ and return a (possibly) different pointer */
       for(int i=0; i<*$2; i++) {
         PyList_SetItem(o, i, PyFloat_FromDouble((double)temp[i]));
       }
-      $result = SWIG_Python_AppendOutput($result, o);
+      $result = SWIG_AppendOutput($result, o);
       SMO_freeMemory(*$1);
     }
 }
@@ -94,7 +95,7 @@ and return a (possibly) different pointer */
         for(int i=0; i<*$2; i++) {
             PyList_SetItem(o, i, PyInt_FromLong((long)temp[i]));
         }
-        $result = SWIG_Python_AppendOutput($result, o);
+        $result = SWIG_AppendOutput($result, o);
         SMO_freeMemory(*$1);
     }
 }

swmm-toolkit/src/swmm/toolkit/solver.i

@@ -31,6 +31,8 @@
 
 %include "stats_typemaps.i";
 
+/* SWIG Override headers*/
+%include "swig_headers.i"
 
 
 /* TYPEMAP FOR IGNORING INT ERROR CODE RETURN VALUE */
@@ -108,7 +110,7 @@
       for(int i=0; i<*$2; i++) {
         PyList_SetItem(o, i, PyFloat_FromDouble(temp$argnum[i]));
       }
-      $result = SWIG_Python_AppendOutput($result, o);
+      $result = SWIG_AppendOutput($result, o);
       swmm_freeMemory(*$1);
     }
 }

swmm-toolkit/src/swmm/toolkit/swig_headers.i

@@ -0,0 +1,38 @@
+
+/* 
+in version 4.3, swig had a breaking change. Python functions that return None 
+no longer implicitly return void. see https://github.com/swig/swig/pull/2907
+and https://github.com/swig/swig/issues/2905
+
+This header block reverts the change from that commit, since I cannot find a 
+more concise way to implicitly make functions that return None just be void.
+
+I think the "correct" way is to define typemap(outs) that match every function
+signature we have and drop the error code accordingly.
+*/
+%header %{
+SWIGINTERN PyObject*
+Custom_SWIG_Python_AppendOutput(PyObject* result, PyObject* obj, int is_void) {
+    if (!result) {
+    result = obj;
+    } else if (result == Py_None) {
+    SWIG_Py_DECREF(result);
+    result = obj;
+    } else {
+    if (!PyList_Check(result)) {
+        PyObject *o2 = result;
+        result = PyList_New(1);
+        if (result) {
+        PyList_SET_ITEM(result, 0, o2);
+        } else {
+        SWIG_Py_DECREF(obj);
+        return o2;
+        }
+    }
+    PyList_Append(result,obj);
+    SWIG_Py_DECREF(obj);
+    }
+    return result;
+}
+#define SWIG_Python_AppendOutput Custom_SWIG_Python_AppendOutput
+%}