speedbar-file-regexp

speedbar-file-regexp is a variable defined in `speedbar.el'.
Its value is

"\\(\\(\\.\\(adb.dg\\|ads.dg\\|adb\\|ads\\|org\\|pro\\|[ch]\\(\\+\\+\\|pp\\|c\\|h\\|xx\\)?\\|tex\\(i\\(nfo\\)?\\)?\\|el\\|emacs\\|l\\|lsp\\|p\\|java\\|js\\|f\\(90\\|77\\|or\\)?\\|ad[abs]\\|p[lm]\\|tcl\\|m\\|scm\\|pm\\|py\\|g\\|s?html\\|ma?k\\)\\)\\|\\(\\.vhdl?\\'\\|[Mm]akefile\\(\\.in\\)?\\)\\)$"

Documentation:
Regular expression matching files we know how to expand.
Created from `speedbar-supported-extension-expressions' with the
function `speedbar-extension-list-to-regex'.