[PATCH] remove nested functions from regcomp.c

[Konstantin Serebryany]

Hi,

Please review the patch that removes nested functions from posix/regcomp.c.
The patch does not noticeably affect the generated code (same
instructions, a few differences in used registers, offsets, etc)
because all the affected functions have __attribute ((always_inline)).

No regressions in 'make check' on x86_64-linux-gnu (Ubuntu 14.04)

This code has some #ifdef branches for "not _LIBC",
please let me know if any separate testing is required for that case.

This change makes GCC emit 4 new warning that all look like this:
==================
regcomp.c: In function ‘parse_expression’:
regcomp.c:2804:21: warning: ‘extra’ may be used uninitialized in this
function [-Wmaybe-uninitialized]
    name_len == extra[idx]
                     ^
regcomp.c:3055:24: note: ‘extra’ was declared here
   const unsigned char *extra;
==================
The warnings look incorrect, since the code is doing this:
  if (nrules)
       extra = ....
  ...
  if (nrules)
     use(extra)

This feature of GCC is known to have various problems and false
positives, but the warnings
did not fire before because nested functions inhibit this warning.
The warnings can be avoided by initializing all these variables to 0
at declaration.

2014-09-29  Kostya Serebryany  <konstantin.s.serebryany@gmail.com>

        * posix/regcomp.c
        (seek_collating_symbol_entry): New function, broken out of
        parse_bracket_exp.
        (lookup_collation_sequence_value): Ditto.
        (build_range_exp): Ditto.
        (build_collating_symbol): Ditto.
        (parse_bracket_exp): Remove nested functions.  Update call sites.


--kcc
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