[pypy-commit] cffi default: Issue #357: fix the out-of-line ABI mode when we see structs

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r3091:6d56592a5c9b
Date: 2018-01-31 21:39 +0100
http://bitbucket.org/cffi/cffi/changeset/6d56592a5c9b/

Log:	Issue #357: fix the out-of-line ABI mode when we see structs
	containing anonymous unions or vice-versa

diff --git a/c/_cffi_backend.c b/c/_cffi_backend.c
--- a/c/_cffi_backend.c
+++ b/c/_cffi_backend.c
@@ -4796,7 +4796,6 @@
             if (PyText_GetSize(fname) == 0 &&
                     ftype->ct_flags & (CT_STRUCT|CT_UNION)) {
                 /* a nested anonymous struct or union */
-                /* note: it seems we only get here with ffi.verify() */
                 CFieldObject *cfsrc = (CFieldObject *)ftype->ct_extra;
                 for (; cfsrc != NULL; cfsrc = cfsrc->cf_next) {
                     /* broken complexity in the call to get_field_name(),
diff --git a/cffi/model.py b/cffi/model.py
--- a/cffi/model.py
+++ b/cffi/model.py
@@ -352,21 +352,20 @@
         self.fldquals = fldquals
         self.build_c_name_with_marker()
 
-    def has_anonymous_struct_fields(self):
-        if self.fldtypes is None:
-            return False
-        for name, type in zip(self.fldnames, self.fldtypes):
-            if name == '' and isinstance(type, StructOrUnion):
-                return True
-        return False
+    def anonymous_struct_fields(self):
+        if self.fldtypes is not None:
+            for name, type in zip(self.fldnames, self.fldtypes):
+                if name == '' and isinstance(type, StructOrUnion):
+                    yield type
 
-    def enumfields(self):
+    def enumfields(self, expand_anonymous_struct_union=True):
         fldquals = self.fldquals
         if fldquals is None:
             fldquals = (0,) * len(self.fldnames)
         for name, type, bitsize, quals in zip(self.fldnames, self.fldtypes,
                                               self.fldbitsize, fldquals):
-            if name == '' and isinstance(type, StructOrUnion):
+            if (name == '' and isinstance(type, StructOrUnion)
+                    and expand_anonymous_struct_union):
                 # nested anonymous struct/union
                 for result in type.enumfields():
                     yield result
diff --git a/cffi/recompiler.py b/cffi/recompiler.py
--- a/cffi/recompiler.py
+++ b/cffi/recompiler.py
@@ -836,6 +836,10 @@
 
     def _struct_collecttype(self, tp):
         self._do_collect_type(tp)
+        if self.target_is_python:
+            # also requires nested anon struct/unions in ABI mode, recursively
+            for fldtype in tp.anonymous_struct_fields():
+                self._struct_collecttype(fldtype)
 
     def _struct_decl(self, tp, cname, approxname):
         if tp.fldtypes is None:
@@ -884,7 +888,7 @@
                  named_ptr not in self.ffi._parser._included_declarations)):
             if tp.fldtypes is None:
                 pass    # opaque
-            elif tp.partial or tp.has_anonymous_struct_fields():
+            elif tp.partial or any(tp.anonymous_struct_fields()):
                 pass    # field layout obtained silently from the C compiler
             else:
                 flags.append("_CFFI_F_CHECK_FIELDS")
@@ -896,7 +900,8 @@
         flags = '|'.join(flags) or '0'
         c_fields = []
         if reason_for_not_expanding is None:
-            enumfields = list(tp.enumfields())
+            expand_anonymous_struct_union = not self.target_is_python
+            enumfields = list(tp.enumfields(expand_anonymous_struct_union))
             for fldname, fldtype, fbitsize, fqual in enumfields:
                 fldtype = self._field_type(tp, fldname, fldtype)
                 self._check_not_opaque(fldtype,
diff --git a/testing/cffi1/test_re_python.py b/testing/cffi1/test_re_python.py
--- a/testing/cffi1/test_re_python.py
+++ b/testing/cffi1/test_re_python.py
@@ -55,6 +55,8 @@
     typedef struct bar_s { int x; signed char a[]; } bar_t;
     enum foo_e { AA, BB, CC };
     int strlen(const char *);
+    struct with_union { union { int a; char b; }; };
+    union with_struct { struct { int a; char b; }; };
     """)
     ffi.set_source('re_python_pysrc', None)
     ffi.emit_python_code(str(tmpdir.join('re_python_pysrc.py')))
@@ -212,3 +214,14 @@
     ffi.set_source('test_partial_enum', None)
     py.test.raises(VerificationMissing, ffi.emit_python_code,
                    str(tmpdir.join('test_partial_enum.py')))
+
+def test_anonymous_union_inside_struct():
+    # based on issue #357
+    from re_python_pysrc import ffi
+    assert ffi.offsetof("struct with_union", "a") == 0
+    assert ffi.offsetof("struct with_union", "b") == 0
+    assert ffi.sizeof("struct with_union") == ffi.sizeof("int")
+    #
+    assert ffi.offsetof("union with_struct", "a") == 0
+    assert ffi.offsetof("union with_struct", "b") == 4
+    assert ffi.sizeof("union with_struct") >= ffi.sizeof("int") + 1