Author: Armin Rigo <ar...@tunes.org>
Branch:
Changeset: r84052:9f9c409ee27e
Date: 2016-04-30 10:40 +0200
http://bitbucket.org/pypy/pypy/changeset/9f9c409ee27e/
Log: Test and fix for yet another very obscure misfeature of ctypes
diff --git a/rpython/rtyper/lltypesystem/ll2ctypes.py
b/rpython/rtyper/lltypesystem/ll2ctypes.py
--- a/rpython/rtyper/lltypesystem/ll2ctypes.py
+++ b/rpython/rtyper/lltypesystem/ll2ctypes.py
@@ -1009,12 +1009,22 @@
container = _array_of_known_length(T.TO)
container._storage = type(cobj)(cobj.contents)
elif isinstance(T.TO, lltype.FuncType):
+ # cobj is a CFunctionType object. We naively think
+ # that it should be a function pointer. No no no. If
+ # it was read out of an array, say, then it is a *pointer*
+ # to a function pointer. In other words, the read doesn't
+ # read anything, it just takes the address of the function
+ # pointer inside the array. If later the array is modified
+ # or goes out of scope, then we crash. CTypes is fun.
+ # It works if we cast it now to an int and back.
cobjkey = intmask(ctypes.cast(cobj, ctypes.c_void_p).value)
if cobjkey in _int2obj:
container = _int2obj[cobjkey]
else:
+ name = getattr(cobj, '__name__', '?')
+ cobj = ctypes.cast(cobjkey, type(cobj))
_callable = get_ctypes_trampoline(T.TO, cobj)
- return lltype.functionptr(T.TO, getattr(cobj, '__name__',
'?'),
+ return lltype.functionptr(T.TO, name,
_callable=_callable)
elif isinstance(T.TO, lltype.OpaqueType):
if T == llmemory.GCREF:
diff --git a/rpython/rtyper/lltypesystem/test/test_ll2ctypes.py
b/rpython/rtyper/lltypesystem/test/test_ll2ctypes.py
--- a/rpython/rtyper/lltypesystem/test/test_ll2ctypes.py
+++ b/rpython/rtyper/lltypesystem/test/test_ll2ctypes.py
@@ -1405,6 +1405,45 @@
a2 = ctypes2lltype(lltype.Ptr(A), lltype2ctypes(a))
assert a2._obj.getitem(0)._obj._parentstructure() is a2._obj
+ def test_array_of_function_pointers(self):
+ c_source = py.code.Source(r"""
+ #include "src/precommondefs.h"
+ #include <stdio.h>
+
+ typedef int(*funcptr_t)(void);
+ static int forty_two(void) { return 42; }
+ static int forty_three(void) { return 43; }
+ static funcptr_t testarray[2];
+ RPY_EXPORTED void runtest(void cb(funcptr_t *)) {
+ testarray[0] = &forty_two;
+ testarray[1] = &forty_three;
+ fprintf(stderr, "&forty_two = %p\n", testarray[0]);
+ fprintf(stderr, "&forty_three = %p\n", testarray[1]);
+ cb(testarray);
+ testarray[0] = 0;
+ testarray[1] = 0;
+ }
+ """)
+ eci = ExternalCompilationInfo(include_dirs=[cdir],
+ separate_module_sources=[c_source])
+
+ PtrF = lltype.Ptr(lltype.FuncType([], rffi.INT))
+ ArrayPtrF = rffi.CArrayPtr(PtrF)
+ CALLBACK = rffi.CCallback([ArrayPtrF], lltype.Void)
+
+ runtest = rffi.llexternal('runtest', [CALLBACK], lltype.Void,
+ compilation_info=eci)
+ seen = []
+
+ def callback(testarray):
+ seen.append(testarray[0]) # read a PtrF out of testarray
+ seen.append(testarray[1])
+
+ runtest(callback)
+ assert seen[0]() == 42
+ assert seen[1]() == 43
+
+
class TestPlatform(object):
def test_lib_on_libpaths(self):
from rpython.translator.platform import platform
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