Re: Errors of doing "make install-tools" with xen-4.2-unstable?

[Ian Campbell <Ian.Campbell@citrix.com>]

On Fri, 2012-05-11 at 17:10 +0100, Bei Guan wrote:


> No, it doesn't work for me. There is the same error.

Hrm. Since you can reproduce would you mind experimenting a bit to
figure out the correct fix for this?

Perhaps adding -Wno-unused-result to C flags helps (google suggests it
may not)?

Or maybe just assigning to a dummy variable.

Ian.

> My environment and gcc version are like this:
> 
> root@gavin-desktop:~# uname -a
> Linux gavin-desktop 2.6.32-5-xen-amd64 #1 SMP Thu May 19 01:16:47 UTC
> 2011 x86_64 GNU/Linux
> 
> root@gavin-desktop:~# gcc -v
> Using built-in specs.
> Target: x86_64-linux-gnu
> Configured with: ../src/configure -v --with-pkgversion='Ubuntu
> 4.4.3-4ubuntu5'
> --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
> --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
> --enable-shared --enable-multiarch --enable-linker-build-id
> --with-system-zlib --libexecdir=/usr/lib --without-included-gettext
> --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4
> --program-suffix=-4.4 --enable-nls --enable-clocale=gnu
> --enable-libstdcxx-debug --enable-plugin --enable-objc-gc
> --disable-werror --with-arch-32=i486 --with-tune=generic
> --enable-checking=release --build=x86_64-linux-gnu
> --host=x86_64-linux-gnu --target=x86_64-linux-gnu
> Thread model: posix
> gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) 
> 
> 
> 
> 
> Thanks,
> Bei Guan
> 
> 
> 
>  
>         
>         8<------------------------------------------------------
>         
>         # HG changeset patch
>         # User Ian Campbell <ian.campbell@citrix.com>
>         # Date 1336751175 -3600
>         # Node ID 15ed8f45c4e57a1e206af020e0ff17b792108e99
>         # Parent  adc74e492edfee6cf44e433e3e93743a3cf71999
>         blktap: avoid attribute warn_unused_result build failures.
>         
>         I'm not proud of this, but since none of these callers of
>         read/write have any
>         other error handling and return void themselves (for several
>         links up the call
>         chain AFAICT) and because I don't really want to get into a
>         massive reworking
>         of blktap2 I suppose it is at least pragmatic
>         
>         Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>         
>         diff -r adc74e492edf -r 15ed8f45c4e5
>         tools/blktap2/drivers/tapdisk-log.c
>         --- a/tools/blktap2/drivers/tapdisk-log.c       Fri May 11
>         16:19:16 2012 +0100
>         +++ b/tools/blktap2/drivers/tapdisk-log.c       Fri May 11
>         16:46:15 2012 +0100
>         @@ -247,7 +247,7 @@ tlog_flush(void)
>                wsize = ((size + 511) & (~511));
>         
>                memset(tapdisk_log.buf + size, '\n', wsize - size);
>         -       write(fd, tapdisk_log.buf, wsize);
>         +       (void)write(fd, tapdisk_log.buf, wsize);
>         
>                tapdisk_log.p = tapdisk_log.buf;
>         
>         diff -r adc74e492edf -r 15ed8f45c4e5
>         tools/blktap2/drivers/tapdisk-queue.c
>         --- a/tools/blktap2/drivers/tapdisk-queue.c     Fri May 11
>         16:19:16 2012 +0100
>         +++ b/tools/blktap2/drivers/tapdisk-queue.c     Fri May 11
>         16:46:15 2012 +0100
>         @@ -435,7 +435,7 @@ tapdisk_lio_ack_event(struct tqueue *que
>                uint64_t val;
>         
>                if (lio->flags & LIO_FLAG_EVENTFD)
>         -               read(lio->event_fd, &val, sizeof(val));
>         +               (void)read(lio->event_fd, &val, sizeof(val));
>          }
>         
>          static void
>         diff -r adc74e492edf -r 15ed8f45c4e5
>         tools/blktap2/drivers/tapdisk-stream.c
>         --- a/tools/blktap2/drivers/tapdisk-stream.c    Fri May 11
>         16:19:16 2012 +0100
>         +++ b/tools/blktap2/drivers/tapdisk-stream.c    Fri May 11
>         16:46:15 2012 +0100
>         @@ -145,7 +145,7 @@ tapdisk_stream_poll_clear(struct tapdisk
>          {
>                int dummy;
>         
>         -       read(p->pipe[POLL_READ], &dummy, sizeof(dummy));
>         +       (void)read(p->pipe[POLL_READ], &dummy, sizeof(dummy));
>                p->set = 0;
>          }
>         
>         @@ -155,7 +155,7 @@ tapdisk_stream_poll_set(struct tapdisk_s
>                int dummy = 0;
>         
>                if (!p->set) {
>         -               write(p->pipe[POLL_WRITE], &dummy,
>         sizeof(dummy));
>         +               (void)write(p->pipe[POLL_WRITE], &dummy,
>         sizeof(dummy));
>                        p->set = 1;
>                }
>          }
>         @@ -203,7 +203,7 @@ tapdisk_stream_print_request(struct tapd
>          {
>                unsigned long idx = (unsigned
>         long)tapdisk_stream_request_idx(s, sreq);
>                char *buf = (char *)MMAP_VADDR(s->vbd->ring.vstart,
>         idx, 0);
>         -       write(s->out_fd, buf, sreq->secs << SECTOR_SHIFT);
>         +       (void)write(s->out_fd, buf, sreq->secs <<
>         SECTOR_SHIFT);
>          }
>         
>          static void
>         diff -r adc74e492edf -r 15ed8f45c4e5
>         tools/blktap2/drivers/tapdisk2.c
>         --- a/tools/blktap2/drivers/tapdisk2.c  Fri May 11 16:19:16
>         2012 +0100
>         +++ b/tools/blktap2/drivers/tapdisk2.c  Fri May 11 16:46:15
>         2012 +0100
>         @@ -79,7 +79,12 @@ main(int argc, char *argv[])
>                if (optind != argc)
>                        usage(argv[0], EINVAL);
>         
>         -       chdir("/");
>         +       if (chdir("/")) {
>         +               DPRINTF("failed to chdir(/): %d\n", errno);
>         +               err = 1;
>         +               goto out;
>         +       }
>         +
>                tapdisk_start_logging("tapdisk2");
>         
>                err = tapdisk_server_init();
>         
>         
> 
> 
> 
> -- 
> Best Regards,
> Bei Guan
>