[patch] inline __getreent in newlib

Christopher Faylor cgf-use-the-mailinglist-please@cygwin.com
Sat Sep 8 02:57:00 GMT 2007

On Fri, Sep 07, 2007 at 04:19:12PM -0700, Brian Dessent wrote:
>Brian Dessent wrote:
>> Done.  I added the following comment to config.h to hopefully clarify
>> the situation:
>> /* The following provides an inline version of __getreent() for newlib,
>>    which will be used throughout the library whereever there is a _r
>>    version of a function that takes _REENT.  This saves the overhead
>>    of a function call for what amounts to a simple computation.
>>    The definition below is essentially equivalent to the one in cygtls.h
>>    (&_my_tls.local_clib) however it uses a fixed precomputed
>>    offset rather than dereferencing a field of a structure.
>>    Including tlsoffets.h here in order to get this constant offset
>>    tls_local_clib is a bit of a hack, but the alternative would require
>>    dragging the entire definition of struct _cygtls (a large and complex
>>    Cygwin internal data structure) into newlib.  The machinery to
>>    compute these offsets already exists for the sake of gendef so
>>    we might as well just use it here.  */
>Turns out that <sys/config.h> includes <cygwin/config.h>, which leads to
>this breakage when the winsup headers are installed in the system
>$ echo "#include <math.h>" | gcc -x c -
>In file included from /usr/include/sys/config.h:180,
>                 from /usr/include/_ansi.h:16,
>                 from /usr/include/sys/reent.h:13,
>                 from /usr/include/math.h:5,
>                 from <stdin>:1:
>/usr/include/cygwin/config.h:22:27: ../tlsoffsets.h: No such file or
>Attached patch fixes the situation by only exposing this when




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