https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82457
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Schepler from comment #2) > I don't follow your explanation. In standard-compliant mode, the compiler > isn't allowed to change the behavior of a function because it's NOT specifed > by a standard? And I'm not sure what you mean by "known identifiers" - if I > include the appropriate headers, they've certainly been declared. And it's > obviously the case that gcc contains some internal code which knows > something or other about the "special" names 'fork', 'execl', etc. What I mean is known to the compiler to have a specific behavior.