Hi! Motivation for bringing this up again: GDB has recently switched from using a C to a C++ compiler. GDB, for obvious reasons, needs to access low-level Hurd/Mach interfaces.
<https://savannah.gnu.org/bugs/?32693> "GNU/Hurd headers don't pass c++" has been closed as "invalid". Additionally to the issues Samuel pointed out in <https://www.sourceware.org/ml/libc-alpha/2007-08/msg00001.html> (still unresolved), I now also ran into: $ echo -e '#include <errno.h>\n#include <mach.h>\nvoid f(){ error_t err = thread_get_state(0,0,0,0); }' | g++ -D_GNU_SOURCE -x c++ - -S -o /dev/null -O2 <stdin>: In function 'void f()': <stdin>:3:41: error: invalid conversion from 'kern_return_t {aka int}' to 'error_t {aka __error_t_codes}' [-fpermissive] That is, for Mach API calls such as thread_get_state, their return type "kern_return_t {aka int}" can't be assigned to (our) error_t type. The Hurd uses its own "typedef enum __error_t_codes error_t;" ([glibc]/sysdeps/mach/hurd/bits/errno.h), contrary to the default "typedef int error_t;" ([glibc]/stdlib/errno.h). Another (inconclusive) discussion thread starts at <https://sourceware.org/ml/libc-alpha/2008-05/msg00123.html>, and if I understand Roland's messages correctly, he has concerns with now changing the error_t type (for __cplusplus), for compatibility reasons. Instead of "error_t err = (error_t) thread_get_state([...])", I guess I'll change such GDB code to plain "int err". Roland, do you still veto against patches such as Samuel's <https://www.sourceware.org/ml/libc-alpha/2007-08/txt00000.txt> (<https://www.sourceware.org/ml/libc-alpha/2007-08/msg00001.html>)? Grüße Thomas
