On 18.01.19 11:11, Richard W.M. Jones wrote: > On FreeBSD 11.2: > > $ nbdkit memory size=1M --run './qemu-io -f raw -c "aio_write 0 512" $nbd' > Parsing error: non-numeric argument, or extraneous/unrecognized suffix -- > aio_write > > After main option parsing, we reinitialize optind so we can parse each > command. However reinitializing optind to 0 does not work on FreeBSD. > What happens when you do this is optind remains 0 after the option > parsing loop, and the result is we try to parse argv[optind] == > argv[0] == "aio_write" as if it was the first parameter. > > The FreeBSD manual page says: > > In order to use getopt() to evaluate multiple sets of arguments, or to > evaluate a single set of arguments multiple times, the variable optreset > must be set to 1 before the second and each additional set of calls to > getopt(), and the variable optind must be reinitialized. > > (From the rest of the man page it is clear that optind must be > reinitialized to 1). > > The glibc man page says: > > A program that scans multiple argument vectors, or rescans the same > vector more than once, and wants to make use of GNU extensions such as > '+' and '-' at the start of optstring, or changes the value of > POSIXLY_CORRECT between scans, must reinitialize getopt() by resetting > optind to 0, rather than the traditional value of 1. (Resetting to 0 > forces the invocation of an internal initialization routine that > rechecks POSIXLY_CORRECT and checks for GNU extensions in optstring.) > > This commit introduces an OS-portability function called > qemu_reset_optind which provides a way of resetting optind that works > on FreeBSD and platforms that use optreset, while keeping it the same > as now on other platforms. > > Note that the qemu codebase sets optind in many other places, but in > those other places it's setting a local variable and not using getopt. > This change is only needed in places where we are using getopt and the > associated global variable optind. > > Signed-off-by: Richard W.M. Jones <[email protected]> > --- > configure | 14 ++++++++++++++ > include/qemu/osdep.h | 16 ++++++++++++++++ > qemu-img.c | 2 +- > qemu-io-cmds.c | 2 +- > 4 files changed, 32 insertions(+), 2 deletions(-) > > diff --git a/configure b/configure > index 3eee3fcf70..3d46df1517 100755
(I'm not quite sure where along the way just using a weak optreset was
discarded, but, oh well, this does make the code less ugly.)
[...]
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 80df7253db..840af09cb0 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -109,6 +109,7 @@ extern int daemon(int, int);
> #include <ctype.h>
> #include <errno.h>
> #include <fcntl.h>
> +#include <getopt.h>
> #include <sys/stat.h>
> #include <sys/time.h>
> #include <assert.h>
> @@ -604,4 +605,19 @@ extern int qemu_icache_linesize_log;
> extern int qemu_dcache_linesize;
> extern int qemu_dcache_linesize_log;
>
> +/*
> + * After using getopt or getopt_long, if you need to parse another set
> + * of options, then you must reset optind. Unfortunately the way to
> + * do this varies between implementations of getopt.
> + */
> +static inline void qemu_reset_optind(void)
> +{
> +#ifdef HAVE_OPTRESET
> + optind = 1;
> + optreset = 1;
> +#else
> + optind = 0;
So I take it this is supposed to always do a hard reset -- because if it
isn't, it might have been better to just always set optind = 1 as Eric
suggested. But googling suggests OpenBSD and NetBSD both have optreset
as well, and newlib accepts optind = 0 (and apparently did not accept
optind = 1 in the past?), so I think this is good for that purpose.
So thanks a lot (and sorry about me being so stupid about
everything...), I've applied the patch to my block branch:
https://git.xanclic.moe/XanClic/qemu/commits/branch/block
Max
> +#endif
> +}
> +
> #endif
signature.asc
Description: OpenPGP digital signature
