From abd22f12734589a225244018eec8087e1bd66e05 Mon Sep 17 00:00:00 2001
From: Dave Abrahams <dave@boostpro.com>
Date: Sat, 14 Dec 2002 00:10:52 +0000
Subject: [PATCH] Handle unsigned long values that don't fit in a long.

[SVN r16606]
---
 .../python/converter/builtin_converters.hpp   | 10 ++-
 src/converter/builtin_converters.cpp          | 63 ++++++++++++++-----
 test/test_builtin_converters.py               |  7 +++
 3 files changed, 61 insertions(+), 19 deletions(-)

diff --git a/include/boost/python/converter/builtin_converters.hpp b/include/boost/python/converter/builtin_converters.hpp
index c46e7e8f..5ec25056 100644
--- a/include/boost/python/converter/builtin_converters.hpp
+++ b/include/boost/python/converter/builtin_converters.hpp
@@ -10,6 +10,7 @@
 # include <boost/python/handle.hpp>
 # include <string>
 # include <complex>
+# include <limits>
 
 // Since all we can use to decide how to convert an object to_python
 // is its C++ type, there can be only one such converter for each
@@ -80,9 +81,12 @@ namespace detail
         BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE(T,expr)
 
 // Specialize converters for signed and unsigned T to Python Int
-# define BOOST_PYTHON_TO_INT(T)                                         \
-    BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed T, PyInt_FromLong(x))        \
-    BOOST_PYTHON_TO_PYTHON_BY_VALUE(unsigned T, PyInt_FromLong(x))
+# define BOOST_PYTHON_TO_INT(T)                                                         \
+    BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed T, PyInt_FromLong(x))                        \
+    BOOST_PYTHON_TO_PYTHON_BY_VALUE(                                                    \
+        unsigned T, static_cast<unsigned long>(x) > std::numeric_limits<long>::max()    \
+        ? PyLong_FromUnsignedLong(x)                                                    \
+        : PyInt_FromLong(x))
 
 // Bool is not signed.
 BOOST_PYTHON_TO_PYTHON_BY_VALUE(bool, PyInt_FromLong(x))
diff --git a/src/converter/builtin_converters.cpp b/src/converter/builtin_converters.cpp
index ce842b12..5c08c945 100644
--- a/src/converter/builtin_converters.cpp
+++ b/src/converter/builtin_converters.cpp
@@ -65,8 +65,8 @@ namespace
       }
   };
 
-  // A SlotPolicy for extracting integer types from Python objects
-  struct int_rvalue_from_python_base
+  // A SlotPolicy for extracting signed integer types from Python objects
+  struct signed_int_rvalue_from_python_base
   {
       static unaryfunc* get_slot(PyObject* obj)
       {
@@ -80,7 +80,7 @@ namespace
   };
 
   template <class T>
-  struct int_rvalue_from_python : int_rvalue_from_python_base
+  struct signed_int_rvalue_from_python : signed_int_rvalue_from_python_base
   {
       static T extract(PyObject* intermediate)
       {
@@ -88,6 +88,41 @@ namespace
       }
   };
 
+  // identity_unaryfunc/py_object_identity -- manufacture a unaryfunc
+  // "slot" which just returns its argument. 
+  extern "C" PyObject* identity_unaryfunc(PyObject* x)
+  {
+      Py_INCREF(x);
+      return x;
+  }
+  unaryfunc py_object_identity = identity_unaryfunc;
+
+  // A SlotPolicy for extracting unsigned integer types from Python objects
+  struct unsigned_int_rvalue_from_python_base
+  {
+      static unaryfunc* get_slot(PyObject* obj)
+      {
+          PyNumberMethods* number_methods = obj->ob_type->tp_as_number;
+          if (number_methods == 0)
+              return 0;
+
+          return (PyInt_Check(obj) || PyLong_Check(obj))
+              ? &py_object_identity : 0;
+      }
+  };
+
+  template <class T>
+  struct unsigned_int_rvalue_from_python : unsigned_int_rvalue_from_python_base
+  {
+      static T extract(PyObject* intermediate)
+      {
+          return numeric_cast<T>(
+              PyLong_Check(intermediate)
+              ? PyLong_AsUnsignedLong(intermediate)
+              : PyInt_AS_LONG(intermediate));
+      }
+  };
+
 // Checking Python's macro instead of Boost's - we don't seem to get
 // the config right all the time. Furthermore, Python's is defined
 // when long long is absent but __int64 is present.
@@ -155,17 +190,6 @@ namespace
   };
 #endif 
 
-  // identity_unaryfunc/py_object_identity -- manufacture a unaryfunc
-  // "slot" which just returns its argument. Used for bool
-  // conversions, since all Python objects are directly convertible to
-  // bool
-  extern "C" PyObject* identity_unaryfunc(PyObject* x)
-  {
-      Py_INCREF(x);
-      return x;
-  }
-  unaryfunc py_object_identity = identity_unaryfunc;
-
   // A SlotPolicy for extracting bool from a Python object
   struct bool_rvalue_from_python
   {
@@ -282,8 +306,15 @@ BOOST_PYTHON_DECL PyObject* do_arg_to_python(PyObject* x)
     return x;
 }
 
-#define REGISTER_INT_CONVERTERS(U) slot_rvalue_from_python<U,int_rvalue_from_python<U> >()
-#define REGISTER_INT_CONVERTERS2(U) REGISTER_INT_CONVERTERS(signed U); REGISTER_INT_CONVERTERS(unsigned U)  
+#define REGISTER_INT_CONVERTERS(signedness, U)                          \
+        slot_rvalue_from_python<                                        \
+                signedness U                                            \
+                ,signedness##_int_rvalue_from_python<signedness U>      \
+         >()
+
+#define REGISTER_INT_CONVERTERS2(U)             \
+        REGISTER_INT_CONVERTERS(signed, U);     \
+        REGISTER_INT_CONVERTERS(unsigned, U)  
 
 void initialize_builtin_converters()
 {
diff --git a/test/test_builtin_converters.py b/test/test_builtin_converters.py
index e4d8b335..80e2149d 100644
--- a/test/test_builtin_converters.py
+++ b/test/test_builtin_converters.py
@@ -38,6 +38,13 @@ r"""
 42
 >>> rewrap_value_unsigned_long(42)
 42
+
+    test unsigned long values which don't fit in a signed long.
+    strip any 'L' characters in case the platform has > 32 bit longs
+        
+>>> hex(rewrap_value_unsigned_long(0x80000001L)).replace('L','')
+'0x80000001'
+
 >>> rewrap_value_long_long(42)
 42L
 >>> rewrap_value_unsigned_long_long(42)