parser: change naming of typedef of anonymous entities to fix clang 16+

Starting from libclang 16, typedefs of anonymous entities such as

	typedef struct {
		/* ... */
	} foo;

will no longer have an empty name for cursor.spelling. Instead, the
returned name will be cursor.type.spelling, matching the name of the
typedef, i.e. "foo" in the above case.

cursor.is_anonymous() will also be false for such entities, regardless
of libclang version.

Rather than try to coerce libclang 16 to the @anonymous_<sha1> naming
convention we have, manually use the same naming for libclang 15 and
earlier. It's arguably a more useful name anyway.

We first have to distinguish regular anonymous entities using
cursor.is_anonymous(). For libclang 15 and earlier, to distinguish from
typedef of anonyous entities. For libclang 16 and later, the name will
be of the form "unnamed ... at /path/to/file".

src/hawkmoth/parser.py

@@ -532,9 +532,15 @@ def _type_definition_fixup(cursor):
     type_elem = []
 
     # Short cut for anonymous symbols.
-    if cursor.spelling == '':
+    if cursor.is_anonymous():
         return None
 
+    # libclang 16 and later have cursor.spelling == cursor.type.spelling for
+    # typedefs of anonymous entities, while libclang 15 and earlier have an
+    # empty string. Match the behaviour across libclang versions.
+    if cursor.spelling == '':
+        return cursor.type.spelling
+
     type_elem.extend(_specifiers_fixup(cursor, cursor.type))
 
     colon_suffix = ''

test/c/typedef-enum.rst

@@ -9,7 +9,7 @@
       named enumeration
 
 
-.. c:enum:: @anonymous_90372874a3c8c25dccf983612f39e93f
+.. c:enum:: unnamed_t
 
    unnamed typedeffed enum
 

test/c/typedef-struct.rst

@@ -9,7 +9,7 @@
       named member
 
 
-.. c:struct:: @anonymous_7f9a1d628cd33f3227f3fcdc3a405aa6
+.. c:struct:: typedef_struct
 
    unnamed typedeffed struct
 

test/cpp/typedef-enum.rst

@@ -9,7 +9,7 @@
       named enumeration
 
 
-.. cpp:enum:: @anonymous_90372874a3c8c25dccf983612f39e93f
+.. cpp:enum:: unnamed_t
 
    unnamed typedeffed enum
 

test/cpp/typedef-struct.rst

@@ -9,7 +9,7 @@
       named member
 
 
-.. cpp:struct:: @anonymous_7f9a1d628cd33f3227f3fcdc3a405aa6
+.. cpp:struct:: typedef_struct
 
    unnamed typedeffed struct