[pypy-commit] cffi default: Complain more readily about opaque enums, by refusing to guess which

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r2373:0fc618efb98b
Date: 2015-11-05 09:09 +0100
http://bitbucket.org/cffi/cffi/changeset/0fc618efb98b/

Log:	Complain more readily about opaque enums, by refusing to guess which
	integer type (unsigned/signed, int/long) it is meant to be.

diff --git a/cffi/model.py b/cffi/model.py
--- a/cffi/model.py
+++ b/cffi/model.py
@@ -514,12 +514,15 @@
         if self.baseinttype is not None:
             return self.baseinttype.get_cached_btype(ffi, finishlist)
         #
+        from . import api
         if self.enumvalues:
             smallest_value = min(self.enumvalues)
             largest_value = max(self.enumvalues)
         else:
-            smallest_value = 0
-            largest_value = 0
+            raise api.CDefError("%r has no values explicitly defined: "
+                                "refusing to guess which integer type it is "
+                                "meant to be (unsigned/signed, int/long)"
+                                % self._get_c_name())
         if smallest_value < 0:   # needs a signed type
             sign = 1
             candidate1 = PrimitiveType("int")
diff --git a/testing/cffi0/backend_tests.py b/testing/cffi0/backend_tests.py
--- a/testing/cffi0/backend_tests.py
+++ b/testing/cffi0/backend_tests.py
@@ -1335,7 +1335,8 @@
         # these depend on user-defined data, so should not be shared
         assert ffi1.typeof("struct foo") is not ffi2.typeof("struct foo")
         assert ffi1.typeof("union foo *") is not ffi2.typeof("union foo*")
-        assert ffi1.typeof("enum foo") is not ffi2.typeof("enum foo")
+        # the following test is an opaque enum, which we no longer support
+        #assert ffi1.typeof("enum foo") is not ffi2.typeof("enum foo")
         # sanity check: twice 'ffi1'
         assert ffi1.typeof("struct foo*") is ffi1.typeof("struct foo *")
 
@@ -1347,6 +1348,14 @@
         assert ffi.getctype("pe") == 'e *'
         assert ffi.getctype("e1*") == 'e1 *'
 
+    def test_opaque_enum(self):
+        ffi = FFI(backend=self.Backend())
+        ffi.cdef("enum foo;")
+        e = py.test.raises(CDefError, ffi.cast, "enum foo", -1)
+        assert str(e.value) == (
+            "'enum foo' has no values explicitly defined: refusing to guess "
+            "which integer type it is meant to be (unsigned/signed, int/long)")
+
     def test_new_ctype(self):
         ffi = FFI(backend=self.Backend())
         p = ffi.new("int *")