[PATCH 3/7] Allow conversion of pointers to Python int

[Tom Tromey <tom@tromey.com>]

PR python/18170 questions why it's not possible to convert a pointer
value to a Python int.

Digging a bit shows that the Python 2.7 int() constructor will happily
return a long in some cases.  And, it seems gdb already understands
this in other places -- this is why gdb_py_object_from_longest
handles.

So, this patch simply extends valpy_int to allow pointer conversions,
as valpy_long does.

gdb/ChangeLog
2018-09-14  Tom Tromey  <tom@tromey.com>

	PR python/18170:
	* python/py-value.c (valpy_int): Allow conversion from pointer
	type.

gdb/testsuite/ChangeLog
2018-09-14  Tom Tromey  <tom@tromey.com>

	PR python/18170:
	* gdb.python/py-value.exp (test_value_numeric_ops): Add tests to
	convert pointers to int and long.
---
 gdb/ChangeLog                         | 6 ++++++
 gdb/python/py-value.c                 | 3 ++-
 gdb/testsuite/ChangeLog               | 6 ++++++
 gdb/testsuite/gdb.python/py-value.exp | 3 +++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c
index 5c6792f85fc..26e91ff2b27 100644
--- a/gdb/python/py-value.c
+++ b/gdb/python/py-value.c
@@ -1503,7 +1503,8 @@ valpy_int (PyObject *self)
 	  value = value_cast (type, value);
 	}
 
-      if (!is_integral_type (type))
+      if (!is_integral_type (type)
+	  && TYPE_CODE (type) != TYPE_CODE_PTR)
 	error (_("Cannot convert value to int."));
 
       l = value_as_long (value);
diff --git a/gdb/testsuite/gdb.python/py-value.exp b/gdb/testsuite/gdb.python/py-value.exp
index aed50d1c8cf..222cf1dea6f 100644
--- a/gdb/testsuite/gdb.python/py-value.exp
+++ b/gdb/testsuite/gdb.python/py-value.exp
@@ -129,6 +129,9 @@ proc test_value_numeric_ops {} {
   gdb_test "print (void *) 5" ".*" ""
   gdb_test_no_output "python b = gdb.history (0)" ""
 
+  gdb_test "python print(int(b))" "5" "convert pointer to int"
+  gdb_test "python print(long(b))" "5" "convert pointer to long"
+
   gdb_test "python print ('result = ' + str(a+5))" " = 0x7( <.*>)?" "add pointer value with python integer"
   gdb_test "python print ('result = ' + str(b-2))" " = 0x3( <.*>)?" "subtract python integer from pointer value"
   gdb_test "python print ('result = ' + str(b-a))" " = 3" "subtract two pointer values"
-- 
2.17.1