bibtex-parse-keys is a compiled Lisp function in `bibtex.el'.

(bibtex-parse-keys &optional ABORTABLE VERBOSE)

Set `bibtex-reference-keys' to the keys used in the whole buffer.
Find both entry keys and crossref entries. If ABORTABLE is non-nil abort
on user input. If VERBOSE is non-nil give messages about progress.
Return alist of keys if parsing was completed, `aborted' otherwise.
If `bibtex-parse-keys-fast' is non-nil, use fast but simplified algorithm
for parsing BibTeX keys. If parsing fails, try to set this variable to nil.