Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

big_pipe_page_attachments in core/modules/big_pipe/big_pipe.module
Implements hook_page_attachments().
book_test_page_attachments in core/modules/book/tests/modules/book_test/book_test.module
Implements hook_page_attachments().
common_test_page_attachments in core/modules/system/tests/modules/common_test/common_test.module
Implements hook_page_attachments().
content_translation_page_attachments in core/modules/content_translation/content_translation.module
Implements hook_page_attachments().
contextual_page_attachments in core/modules/contextual/contextual.module
Implements hook_page_attachments().
outside_in_test_css_page_attachments in core/modules/outside_in/tests/modules/outside_in_test_css/outside_in_test_css.module
Implements hook_page_attachments().
quickedit_page_attachments in core/modules/quickedit/quickedit.module
Implements hook_page_attachments().
system_page_attachments in core/modules/system/system.module
Implements hook_page_attachments().
system_test_page_attachments in core/modules/system/tests/modules/system_test/system_test.module
Implements hook_page_attachments().