Add anonymous nested union

Author: andreax79

cstruct/c_parser.py

@@ -182,6 +182,7 @@ def parse_struct(
     flexible_array: bool = False
     offset: int = 0
     max_alignment: int = 0
+    anonymous: int = 0
     if isinstance(__struct__, Tokens):
         tokens = __struct__
     else:
@@ -197,6 +198,16 @@ def parse_struct(
         vname = tokens.pop()
         if vname in fields_types:
             raise ParserError("Duplicate member '{}'".format(vname))
+        # anonymous nested union
+        if vname == ';' and field_type.ref is not None and (__is_union__ or field_type.ref.__is_union__):
+            # add the anonymous struct fields to the parent
+            for nested_field_name, nested_field_type in field_type.ref.__fields_types__.items():
+                if nested_field_name in fields_types:
+                    raise ParserError("Duplicate member '{}'".format(nested_field_name))
+                fields_types[nested_field_name] = nested_field_type
+            vname = "__anonymous{}".format(anonymous)
+            anonymous += 1
+            tokens.push(';')
         fields_types[vname] = field_type
         # calculate the max field size (for the alignment)
         max_alignment = max(max_alignment, field_type.alignment)

tests/test_nested.py

@@ -0,0 +1,212 @@
+#!/usr/bin/env python
+# *****************************************************************************
+#
+# Copyright (c) 2013-2019 Andrea Bonomi <andrea.bonomi@gmail.com>
+#
+# Published under the terms of the MIT license.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+#
+# *****************************************************************************
+
+import pytest
+import cstruct
+from cstruct import sizeof
+from cstruct.exceptions import ParserError
+
+
+INVALID_ANONYMOUS = """
+    struct NestedStruct {
+        struct {
+          int a;
+          int b;
+        };
+        int a;
+        int b;
+    };
+"""
+
+
+class NestedStruct(cstruct.MemCStruct):
+    __byte_order__ = cstruct.LITTLE_ENDIAN
+    __def__ = """
+        struct NestedStruct {
+            struct {
+              int a;
+              int b;
+            } s;
+            int a;
+            int b;
+        };
+    """
+
+
+class NestedUnion(cstruct.MemCStruct):
+    __byte_order__ = cstruct.LITTLE_ENDIAN
+    __def__ = """
+        union NestedUnion {
+            struct {
+              int a;
+              int b;
+            } s;
+            int a;
+        };
+    """
+
+
+class NestedAnonymousUnion(cstruct.MemCStruct):
+    __byte_order__ = cstruct.LITTLE_ENDIAN
+    __def__ = """
+        union NestedAnonymousUnion {
+            struct {
+              int a;
+              int b;
+            };
+            int c;
+        };
+    """
+
+
+class Packet(cstruct.MemCStruct):
+    __byte_order__ = cstruct.LITTLE_ENDIAN
+    __def__ = """
+        #define MaxPacket 20
+
+        struct Packet {
+            uint8_t packetLength;
+            union {
+                uint8_t bytes[MaxPacket];
+                struct {
+                    uint16_t field1;
+                    uint16_t field2;
+                    uint16_t field3;
+                } format1;
+                struct {
+                    double value1;
+                    double value2;
+                } format2;
+            };
+        };
+    """
+
+
+def test_invalid_anonymous():
+    with pytest.raises(ParserError):
+        cstruct.parse(INVALID_ANONYMOUS)
+    assert True
+
+
+def test_sizeof_nested_struct():
+    assert sizeof('struct NestedStruct') == 16
+    o = NestedStruct()
+    assert len(o) == 16
+
+
+def test_pack_unpack_nested_struct():
+    o = NestedStruct()
+    o.s.a = 1
+    o.s.b = 2
+    o.a = 10
+    o.b = 20
+    b = o.pack()
+    o1 = NestedStruct()
+
+    o1.unpack(b)
+    assert o1.s.a == 1
+    assert o1.s.b == 2
+    assert o1.a == 10
+    assert o1.b == 20
+
+
+def test_sizeof_nested_union():
+    assert sizeof('struct NestedUnion') == 8
+    o = NestedUnion()
+    assert len(o) == 8
+
+
+def test_pack_unpack_nested_union():
+    o = NestedUnion()
+    o.s.a = 1
+    o.s.b = 2
+    b = o.pack()
+
+    o1 = NestedUnion()
+    o1.unpack(b)
+    assert o1.s.a == 1
+    assert o1.s.b == 2
+
+    o = NestedUnion()
+    o.a = 1979
+    b = o.pack()
+
+    o1 = NestedUnion()
+    o1.unpack(b)
+    assert o1.a == 1979
+    o1.s.b = 0
+    assert o1.a == 1979
+    o1.s.a = 0
+    assert o1.a == 0
+
+
+def test_sizeof_nested_anonymous_union():
+    assert sizeof('struct NestedAnonymousUnion') == 8
+    o = NestedAnonymousUnion()
+    assert len(o) == 8
+
+
+def test_pack_unpack_nested_anonymous_union():
+    o = NestedAnonymousUnion()
+    o.a = 1
+    o.b = 2
+    b = o.pack()
+
+    o1 = NestedAnonymousUnion()
+    o1.unpack(b)
+    assert o1.a == 1
+    assert o1.b == 2
+
+    o = NestedAnonymousUnion()
+    o.c = 1979
+    b = o.pack()
+
+    o1 = NestedAnonymousUnion()
+    o1.unpack(b)
+    assert o1.c == 1979
+    o1.b = 0
+    assert o1.c == 1979
+    o1.a = 0
+    assert o1.c == 0
+
+
+def test_nested_anonymous_union_struct():
+    o = Packet()
+    assert sizeof("struct Packet") == len(o)
+
+    o = Packet()
+    o.packetLength = 10
+    o.format1.field1 = 11
+    o.format1.field2 = 12
+    o.format1.field3 = 13
+    b = o.pack()
+
+    o1 = Packet()
+    o1.unpack(b)
+    assert o1.format1.field1 == 11
+    assert o1.format1.field2 == 12
+    assert o1.format1.field3 == 13