Fix 32bit pointer support

dissect/cstruct/cstruct.py

@@ -2,7 +2,7 @@
 
 import ctypes as _ctypes
 import sys
-from typing import Any, BinaryIO
+from typing import Any, BinaryIO, Optional
 
 from dissect.cstruct.exceptions import ResolveError
 from dissect.cstruct.parser import CStyleParser, TokenParser
@@ -30,7 +30,7 @@ class cstruct:
     DEF_CSTYLE = 1
     DEF_LEGACY = 2
 
-    def __init__(self, endian: str = "<", pointer: str = None):
+    def __init__(self, endian: str = "<", pointer: Optional[str] = None):
         self.endian = endian
 
         self.consts = {}
@@ -146,7 +146,7 @@ def __init__(self, endian: str = "<", pointer: str = None):
         }
         # fmt: on
 
-        pointer = pointer or "uint64" if sys.maxsize > 2**32 else "uint32"
+        pointer = pointer or ("uint64" if sys.maxsize > 2**32 else "uint32")
         self.pointer = self.resolve(pointer)
         self._anonymous_count = 0
 

tests/test_align.py

@@ -286,9 +286,11 @@ def test_align_pointer():
         uint16  d;
     };
     """
-    c = cstruct.cstruct()
+    c = cstruct.cstruct(pointer="uint64")
     c.load(d, align=True)
 
+    assert c.pointer is c.uint64
+
     fields = c.test.fields
     assert c.test.align
     assert c.test.alignment == 8

tests/test_pointer.py

@@ -1,3 +1,5 @@
+from unittest.mock import patch
+
 import pytest
 from dissect import cstruct
 
@@ -18,6 +20,7 @@ def test_pointer_basic(compiled):
     cs.load(cdef, compiled=compiled)
 
     assert verify_compiled(cs.ptrtest, compiled)
+    assert cs.pointer is cs.uint16
 
     buf = b"\x04\x00\x08\x00\x01\x02\x03\x04\x05\x06\x07\x08"
     obj = cs.ptrtest(buf)
@@ -63,6 +66,7 @@ def test_pointer_struct(compiled):
 
     assert verify_compiled(cs.test, compiled)
     assert verify_compiled(cs.ptrtest, compiled)
+    assert cs.pointer is cs.uint16
 
     buf = b"\x02\x00testt\x00e\x00s\x00t\x00\x01\x02\x03\x04\x05\x06\x07lalala\x00t\x00e\x00s\x00t\x00\x00\x00"
     obj = cs.ptrtest(buf)
@@ -95,6 +99,7 @@ def test_array_of_pointers(compiled):
     cs.load(cdef, compiled=compiled)
 
     assert verify_compiled(cs.mainargs, compiled)
+    assert cs.pointer is cs.uint16
 
     buf = b"\x02\x09\x00\x16\x00\x00\x00\x00\x00argument one\x00argument two\x00"
     obj = cs.mainargs(buf)
@@ -142,3 +147,16 @@ def test_pointer_arithmetic():
 
     inst |= 8
     assert inst._addr == 12
+
+
+def test_pointer_sys_size():
+    with patch("sys.maxsize", 2**64):
+        c = cstruct.cstruct()
+        assert c.pointer is c.uint64
+
+    with patch("sys.maxsize", 2**32):
+        c = cstruct.cstruct()
+        assert c.pointer is c.uint32
+
+    c = cstruct.cstruct(pointer="uint16")
+    assert c.pointer is c.uint16