Test and fix: refuse to 'recompile' a cdef that declares a struct

with an opaque struct as a field

2 files changed, 41 insertions, 0 deletions

diff --git a/cffi/recompiler.py b/cffi/recompiler.py
index 0aed988..eb7c891 100644
--- a/cffi/recompiler.py
+++ b/cffi/recompiler.py
@@ -862,6 +862,8 @@ class Recompiler:
             enumfields = list(tp.enumfields())
             for fldname, fldtype, fbitsize, fqual in enumfields:
                 fldtype = self._field_type(tp, fldname, fldtype)
+                self._check_not_opaque(fldtype,
+                                       "field '%s.%s'" % (tp.name, fldname))
                 # cname is None for _add_missing_struct_unions() only
                 op = OP_NOOP
                 if fbitsize >= 0:
@@ -911,6 +913,13 @@ class Recompiler:
                             first_field_index, c_fields))
         self._seen_struct_unions.add(tp)
 
+    def _check_not_opaque(self, tp, location):
+        while isinstance(tp, model.ArrayType):
+            tp = tp.item
+        if isinstance(tp, model.StructOrUnion) and tp.fldtypes is None:
+            raise TypeError(
+                "%s is of an opaque type (not declared in cdef())" % location)
+
     def _add_missing_struct_unions(self):
         # not very nice, but some struct declarations might be missing
         # because they don't have any known C name.  Check that they are
diff --git a/testing/cffi1/test_recompiler.py b/testing/cffi1/test_recompiler.py
index 1bd1da2..d1fadfc 100644
--- a/testing/cffi1/test_recompiler.py
+++ b/testing/cffi1/test_recompiler.py
@@ -1918,3 +1918,35 @@ def test_bool_in_cpp():
     ffi.cdef("bool f(void);")
     lib = verify(ffi, "test_bool_in_cpp", "char f(void) { return 2; }")
     assert lib.f() == 1
+
+def test_struct_field_opaque():
+    ffi = FFI()
+    ffi.cdef("struct a { struct b b; };")
+    e = py.test.raises(TypeError, verify,
+                       ffi, "test_struct_field_opaque", "?")
+    assert str(e.value) == ("struct a: field 'a.b' is of an opaque"
+                            " type (not declared in cdef())")
+    ffi = FFI()
+    ffi.cdef("struct a { struct b b[2]; };")
+    e = py.test.raises(TypeError, verify,
+                       ffi, "test_struct_field_opaque", "?")
+    assert str(e.value) == ("struct a: field 'a.b' is of an opaque"
+                            " type (not declared in cdef())")
+    ffi = FFI()
+    ffi.cdef("struct a { struct b b[]; };")
+    e = py.test.raises(TypeError, verify,
+                       ffi, "test_struct_field_opaque", "?")
+    assert str(e.value) == ("struct a: field 'a.b' is of an opaque"
+                            " type (not declared in cdef())")
+
+def test_function_arg_opaque():
+    py.test.skip("can currently declare a function with an opaque struct "
+                 "as argument, but AFAICT it's impossible to call it later")
+
+def test_function_returns_opaque():
+    ffi = FFI()
+    ffi.cdef("struct a foo(int);")
+    e = py.test.raises(TypeError, verify,
+                       ffi, "test_function_returns_opaque", "?")
+    assert str(e.value) == ("function foo: 'struct a' is used as result type,"
+                            " but is opaque")