Merge pull request #725 from karthikr-vti/main

Types corrected as per VISA 7.2 spec(visa.h)
pyvisa · Jan 27, 2023 · 67744e5 · 67744e5
2 parents c76286f + ba7a8c9
commit 67744e5
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Showing 2 changed files with 9 additions and 3 deletions.
diff --git a/CHANGES b/CHANGES
@@ -1,6 +1,10 @@
 PyVISA Changelog
 ================
 
+1.14.0 (unreleased)
+-------------------
+- fix ctypes truncated pointers on 64-bit for ViBusAddress, ViBusSize, ViAttrState PR # 725
+
 1.13.0 (22-12-2022)
 -------------------
 

diff --git a/pyvisa/ctwrapper/types.py b/pyvisa/ctwrapper/types.py
@@ -13,6 +13,7 @@
 
 """
 import ctypes as _ctypes
+import sys
 
 from .cthelper import FUNCTYPE
 
@@ -104,15 +105,16 @@ def from_param(cls, obj):
 # Part Two: Type Assignments for VISA only, see spec table 3.1.2.  The
 # difference to the above is of no significance in Python, so I use it here
 # only for easier synchronisation with the spec.
+is_64bit = sys.maxsize > 2**32
 
 ViAccessMode, ViPAccessMode = _type_pair(ViUInt32)
-ViBusAddress, ViPBusAddress = _type_pair(ViUInt32)
+ViBusAddress, ViPBusAddress = _type_pair(ViUInt64) if is_64bit else _type_pair(ViUInt32)
 ViBusAddress64, ViPBusAddress64 = _type_pair(ViUInt64)
 
-ViBusSize = ViUInt32
+ViBusSize = ViUInt64 if is_64bit else ViUInt32
 ViBusSize64 = ViUInt64
 
-ViAttrState, ViPAttrState = _type_pair(ViUInt32)
+ViAttrState, ViPAttrState = _type_pair(ViUInt64) if is_64bit else _type_pair(ViUInt32)
 
 # The following is weird, taken from news:zn2ek2w2.fsf@python.net
 ViVAList = _ctypes.POINTER(_ctypes.c_char)