feat: add support for typedefs in C-to-Python struct parsing

Author: MrIndeciso

libdestruct/c/struct_parser.py

@@ -196,11 +196,16 @@ def typedef_to_pair(typedef: c_ast.Typedef) -> tuple[str, type[obj]]:
     if not isinstance(typedef, c_ast.Typedef):
         raise TypeError("Definition must be a typedef.")
 
-    if not isinstance(typedef.type, c_ast.TypeDecl):
-        raise TypeError("Definition must be a type declaration.")
-
     name = "".join(typedef.name)
-    definition = type_decl_to_type(typedef.type)
+
+    if isinstance(typedef.type, c_ast.PtrDecl):
+        definition = ptr_to_type(typedef.type)
+    elif isinstance(typedef.type, c_ast.ArrayDecl):
+        definition = arr_to_type(typedef.type)
+    elif isinstance(typedef.type, c_ast.TypeDecl):
+        definition = type_decl_to_type(typedef.type)
+    else:
+        raise TypeError("Unsupported typedef target type.")
 
     return name, definition
 

test/scripts/struct_parser_unit_test.py

@@ -4,9 +4,11 @@
 # Licensed under the MIT license. See LICENSE file in the project root for details.
 #
 
+import struct as pystruct
 import unittest
 
 from libdestruct.c.struct_parser import definition_to_type
+from libdestruct import inflater
 
 
 class StructParserTest(unittest.TestCase):
@@ -39,5 +41,52 @@ def test_nested_struct_definition(self):
         self.assertIn("b", t.__annotations__)
 
 
+class TypedefTest(unittest.TestCase):
+    """Typedef support in C struct parser."""
+
+    def test_simple_typedef(self):
+        t = definition_to_type("""
+            typedef unsigned int uint32_t;
+            struct S { uint32_t x; };
+        """)
+        self.assertIn("x", t.__annotations__)
+
+    def test_typedef_of_struct(self):
+        t = definition_to_type("""
+            typedef struct { int x; } Point;
+            struct S { Point p; };
+        """)
+        self.assertIn("p", t.__annotations__)
+
+    def test_typedef_of_pointer(self):
+        t = definition_to_type("""
+            typedef int *intptr;
+            struct S { intptr p; };
+        """)
+        self.assertIn("p", t.__annotations__)
+
+    def test_typedef_chain(self):
+        t = definition_to_type("""
+            typedef unsigned int u32;
+            typedef u32 mytype;
+            struct S { mytype x; };
+        """)
+        self.assertIn("x", t.__annotations__)
+
+    def test_typedef_inflate_and_read(self):
+        t = definition_to_type("""
+            typedef unsigned int uint32_t;
+            struct S { uint32_t x; int y; };
+        """)
+        memory = bytearray(8)
+        memory[0:4] = pystruct.pack("<I", 0xDEADBEEF)
+        memory[4:8] = pystruct.pack("<i", -42)
+
+        lib = inflater(memory)
+        s = lib.inflate(t, 0)
+        self.assertEqual(s.x.value, 0xDEADBEEF)
+        self.assertEqual(s.y.value, -42)
+
+
 if __name__ == "__main__":
     unittest.main()