Unit tests for ptrdiff_t/size_t max/min in Python

Examples/test-suite/primitive_types.i

@@ -368,6 +368,17 @@ macro(size_t,             pfx, sizet)
   virtual const char* pfx##_##str(type x) { return "name"; }
 %enddef
 
+/* checking size_t and ptrdiff_t typemaps */
+%include "stdint.i"
+%inline {
+  size_t    get_size_min()    { return 0; }
+  size_t    get_size_max()    { return SIZE_MAX; }
+  ptrdiff_t get_ptrdiff_min() { return PTRDIFF_MIN; }
+  ptrdiff_t get_ptrdiff_max() { return PTRDIFF_MAX; }
+
+  size_t    size_echo   (size_t val)    { return val; }
+  ptrdiff_t ptrdiff_echo(ptrdiff_t val) { return val; }
+}
 
 %inline {
   struct Foo

Examples/test-suite/python/primitive_types_runme.py

@@ -573,3 +573,34 @@ if val_double(sys.maxint + 1) != float(sys.maxint + 1):
     raise RuntimeError, "bad double typemap"
 if val_double(-sys.maxint - 2) != float(-sys.maxint - 2):
     raise RuntimeError, "bad double typemap"
+
+
+# Check the minimum and maximum values that fit in ptrdiff_t and size_t
+def checkType(name, maxfunc, maxval, minfunc, minval, echofunc):
+    if maxfunc() != maxval:
+        raise RuntimeError, "bad " + name + " typemap"
+    if minfunc() != minval:
+        raise RuntimeError, "bad " + name + " typemap"
+    if echofunc(maxval) != maxval:
+        raise RuntimeError, "bad " + name + " typemap"
+    if echofunc(minval) != minval:
+        raise RuntimeError, "bad " + name + " typemap"
+    error = 0
+    try:
+        echofunc(maxval + 1)
+        error = 1
+    except OverflowError:
+        pass
+    if error == 1:
+        raise RuntimeError, "bad " + name + " typemap"
+    try:
+        echofunc(minval - 1)
+        error = 1
+    except OverflowError:
+        pass
+    if error == 1:
+        raise RuntimeError, "bad " + name + " typemap"
+
+# sys.maxsize is the largest value supported by Py_ssize_t, which should be the same as ptrdiff_t
+checkType("ptrdiff_t", get_ptrdiff_max, sys.maxsize,           get_ptrdiff_min, -(sys.maxsize + 1), ptrdiff_echo)
+checkType("size_t",    get_size_max,    (2 * sys.maxsize) + 1, get_size_min,    0,                  size_echo)