[gdb/build] Fix build on postmarketos
I tried building gdbserver on postmarketos (which is based on alpine linux,
which uses musl libc), and ran into:
...
gdbserver/linux-low.cc: In lambda function:
gdbserver/linux-low.cc:1907:41: error: \
'W_EXITCODE' was not declared in this scope
1907 | mark_lwp_dead (leader_lp, W_EXITCODE (0, 0), true);
| ^~~~~~~~~~
...
The macro W_EXITCODE is not defined in gdbsupport/gdb_wait.h.
OTOH, WSETEXIT is defined there, but unused:
...
/* These are not defined in POSIX, but are used by our programs. */
#ifndef WSETEXIT
# ifdef W_EXITCODE
#define WSETEXIT(w,status) ((w) = W_EXITCODE(status,0))
# else
#define WSETEXIT(w,status) ((w) = (0 | ((status) << 8)))
# endif
#endif
...
Fix this by dropping the WSETEXIT definition, and instead defining W_EXITCODE.
Tested on x86_64-linux, in combination with an "#undef W_EXITCODE" to make
sure the definition is exercised.
Approved-By: Tom Tromey <tom@tromey.com>
PR build/31483
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31483