Re: [libvirt] [PATCH 05/11] util: use glib string allocation/formatting functions

On Mon, Sep 30, 2019 at 01:35:36PM +0200, Pavel Hrdina wrote: > On Fri, Sep 27, 2019 at 06:17:27PM +0100, Daniel P. Berrangé wrote: > > Convert the string duplication APIs to use the g_strdup family of APIs. > > > > Annoyingly our virVasprintf/virAsprintf functions return the character > > count, even though 90% of our usage doesn't need it. To retain compat > > with these semantics we have a call to strlen which costs CPU time. > > > > We previously used the 'strdup-posix' gnulib module because mingw does > > not set errno to ENOMEM on failure > > > > We previously used the 'strndup' gnulib module because this function > > does not exist on mingw. > > > > We previously used the 'vasprintf' gnulib module because of many GNU > > supported format specifiers not working on non-Linux platforms. glib's > > own equivalent standardizes on GNU format specifiers too. > > > > Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; > > --- > > bootstrap.conf | 3 --- > > src/util/virstring.c | 19 +++++++------------ > > 2 files changed, 7 insertions(+), 15 deletions(-) > > > > diff --git a/bootstrap.conf b/bootstrap.conf > > index 549d18c6d4..b6b75f9301 100644 > > --- a/bootstrap.conf > > +++ b/bootstrap.conf > > @@ -100,8 +100,6 @@ stat-time > > stdarg > > stpcpy > > strchrnul > > -strdup-posix > > -strndup > > strerror > > strerror_r-posix > > strptime > > @@ -117,7 +115,6 @@ uname > > unsetenv > > useless-if-before-free > > usleep > > -vasprintf > > verify > > vc-list-files > > vsnprintf > > diff --git a/src/util/virstring.c b/src/util/virstring.c > > index a4cc7e9c0a..c8c888b2a0 100644 > > --- a/src/util/virstring.c > > +++ b/src/util/virstring.c > > @@ -730,12 +730,9 @@ virVasprintfInternal(char **strp, > > const char *fmt, > > va_list list) > > { > > - int ret; > > + *strp = g_strdup_vprintf(fmt, list); > > > > - if ((ret = vasprintf(strp, fmt, list)) == -1) > > - abort(); > > - > > - return ret; > > + return strlen(*strp); > > This will cause a SEGFAULT if strp is NULL as g_strdup_vprintf doesn't > abort on failure. > > We can use g_vasprintf which returns length. Oh yes, that makes life easier. > But if we want to return only -1 or 0 and let the caller to decide on > the length there are only few places to modify. > > src/nwfilter/nwfilter_dhcpsnoop.c:1770 > src/util/virfile.c:3410

> > These two looks like the only cases where we actually care about the > length. There are some other cases for which we would have to only > tweak to comparison: > > src/libxl/libxl_domain.c:916: > > There is a function virDoubleToStr that returns the length but it's > usage doesn't care about the length so we would have to change the > description. There something else hiding as we break all test suite output if we return 0

Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list