Fix C++ apigen support for macros with Sphinx >= 7.4 (#395)

sphinx_immaterial/apidoc/cpp/symbol_ids.py

@@ -129,16 +129,23 @@ def add_declaration(declaration, docname: str, line: int):
                         symbol.siblingBelow.siblingAbove = siblingAbove
                     symbol.siblingBelow = None
 
-                # Remove duplicate symbol that was just created
-                for other_symbol in symbol.parent._children:
-                    if other_symbol.declaration is declaration:
-                        assert other_symbol.isRedeclaration
-                        other_symbol.remove()
-                        break
+                parent_children = symbol.parent._children
+                if isinstance(parent_children, list):
+                    # Remove duplicate symbol that was just created
+                    for other_symbol in symbol.parent._children:
+                        if other_symbol.declaration is declaration:
+                            assert other_symbol.isRedeclaration
+                            other_symbol.remove()
+                            break
+                    else:
+                        raise AssertionError(
+                            "Duplicate symbol not found: %r" % (symbol.dump(2),)
+                        )
                 else:
-                    raise AssertionError(
-                        "Duplicate symbol not found: %r" % (symbol.dump(2),)
-                    )
+                    # Updated C domain that stores children as a dict and does
+                    # not create duplicates
+                    # (https://github.com/sphinx-doc/sphinx/pull/12162).
+                    pass
             return symbol
 
         parentSymbol.add_declaration = add_declaration

tests/cpp_apigen_test.py

@@ -36,3 +36,39 @@ def test_unnamed_template_parameter(immaterial_make_app):
     app.build()
 
     assert not app._warning.getvalue()
+
+
+def test_macro(immaterial_make_app):
+    app = immaterial_make_app(
+        extra_conf="""
+extensions.append("sphinx_immaterial.apidoc.cpp.apigen")
+""",
+        confoverrides=dict(
+            nitpicky=True,
+            cpp_apigen_configs=[
+                dict(
+                    document_prefix="cpp_apigen_generated/",
+                    api_parser_config=dict(
+                        input_content=r"""
+/// Tests something.
+///
+/// \ingroup Array
+#define IS_ARRAY(x) x + 1
+""",
+                        compiler_flags=["-std=c++17", "-x", "c++"],
+                        verbose=True,
+                    ),
+                ),
+            ],
+        ),
+        files={
+            "index.rst": """
+.. cpp-apigen-group:: Array
+
+"""
+        },
+    )
+
+    app.build()
+
+    assert not app._warning.getvalue()