Sigh. I've been picking my way through this paragraph, looking at the code:
/* This data structure represents a compiled pattern. Before calling the pattern compiler, the fields `buffer', `allocated', `fastmap', `translate', and `no_sub' can be set. After the pattern has been compiled, the `re_nsub' field is available. All other fields are private to the regex routines. */ We observed earlier that there is an omission on the "After" side: not_bol and not_eol are respected during pattern matching (the equivalent of POSIX eflags). What I have only just noticed, and confirmed from the code, is that the list of fields that can be set before compilation is excessive. In paticular, `fastmap' can't be set (you have to call re_compile_fastmap, and `no_sub' can't be set (because re_compile always overwrites it, as it does newline_anchor). Does this analysis look right? I therefore claim that a correct version of the paragraph is: /* This data structure represents a compiled pattern. Before calling the pattern compiler, the fields `buffer', `allocated', and `translate' can be set. After the pattern has been compiled, the fields `re_nsub', `not_bol' and `not_eol' are available. All other fields are private to the regex routines. */ There's one more thing that seems dubious to me, and that's the mention of allocate. Surely you shouldn't be fiddling with it directly, but calling re_set_registers (and similarly fastmap and re_compile_fastmap)? The API function re_set_registers has been available since June 1992 (or perhaps that should be release 0.12 in June 1993), and re_compile_fastmap since before the regex ChangeLog began, i.e. since at least October 1989 (though no later release is documented before 0.12). Still, that seems long enough to at least deprecate the manual setting of those particular fields, at least as mildly as by not mentioning them in the documentation. Hence, I would write: /* This data structure represents a compiled pattern. Before calling the pattern compiler, the fields `buffer' and `translate' can be set. After the pattern has been compiled, the fields `re_nsub', `not_bol' and `not_eol' are available. All other fields are private to the regex routines. */ Again, I would be most grateful for scrutiny and suggestions so I can get the highest quality patch for glibc. -- http://rrt.sc3d.org
