RFR(XS): 8046408: Build failure from multiple ptrace.h

[Staffan Larsen]

Looks good!

Thanks,
/Staffan

On 11 jun 2014, at 17:31, Kim Barrett <kim.barrett at oracle.com> wrote:

> Please review the following 1-line change which is needed to avoid
> build failures on some platforms.
> 
> webrev: http://cr.openjdk.java.net/~mikael/webrevs/kim-8046408/webrev/
> bug: https://bugs.openjdk.java.net/browse/JDK-8046408
> 
> There are two ptrace.h headers available for linux, <sys/ptrace.h> and
> <linux/ptrace.h>.  A new struct (ptrace_peeksiginfo_args) was recently
> added to each, but the addition in <sys/ptrace.h> didn't follow the
> convention there of using a double-underscore prefix for type names
> declared in that file.  As a result, if both headers are included (as
> is occurring in our code), there are multiple definitions of that
> struct.  It appears to be a "well known" problem that already has a
> fix [1], but glibc 2.18 was released with this problem.
> 
> The inclusion of both variants was due to a file (ps_proc.c) directly
> including sys/ptrace and indirectly including linux/ptrace, where the
> indirectly including header is used in other places that don't include
> sys/ptrace.  Our code can presently use either of the headers; I'm
> proposing we prefer sys/ptrace rather than linux/ptrace.  A different
> 1-line change would be to remove the direct include of sys/ptrace and
> let that file rely on the indirect include of linux/ptrace, but I
> dislike that, since ps_proc.c directly uses lots of names defined in
> those headers.
> 
> [1] https://www.sourceware.org/ml/libc-alpha/2014-01/msg00078.html
>