Alberto Garcia <be...@igalia.com> writes:
> This is a bit more efficient than having to allocate and free memory > for each item. > > The default size (60) is enough for all the existing incompatible > features. > > Suggested-by: Philippe Mathieu-Daudé <phi...@redhat.com> > Signed-off-by: Alberto Garcia <be...@igalia.com> > --- > block/qcow2.c | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/block/qcow2.c b/block/qcow2.c > index cef9d72b3a..ecf6827420 100644 > --- a/block/qcow2.c > +++ b/block/qcow2.c > @@ -453,16 +453,15 @@ static void cleanup_unknown_header_ext(BlockDriverState > *bs) > static void report_unsupported_feature(Error **errp, Qcow2Feature *table, > uint64_t mask) > { > - char *features = g_strdup(""); > - char *old; > + GString *features = g_string_sized_new(60); g_autoptr(GString) features = g_string_sized_new(60); will save you the clean-up later. > > while (table && table->name[0] != '\0') { > if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { > if (mask & (1ULL << table->bit)) { > - old = features; > - features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : > "", > - table->name); > - g_free(old); > + if (features->len > 0) { > + g_string_append(features, ", "); > + } > + g_string_append_printf(features, "%.46s", > table->name); We have a number of cases of this sort of idiom in the code base. I wonder if it calls for a utility function: qemu_append_with_sep(features, ", ", "%.46s", table->name) Anyway not mandatory for this patch so with the autoptr fix: Reviewed-by: Alex Bennée <alex.ben...@linaro.org> > mask &= ~(1ULL << table->bit); > } > } > @@ -470,14 +469,15 @@ static void report_unsupported_feature(Error **errp, > Qcow2Feature *table, > } > > if (mask) { > - old = features; > - features = g_strdup_printf("%s%sUnknown incompatible feature: %" > PRIx64, > - old, *old ? ", " : "", mask); > - g_free(old); > + if (features->len > 0) { > + g_string_append(features, ", "); > + } > + g_string_append_printf(features, > + "Unknown incompatible feature: %" PRIx64, > mask); > } > > - error_setg(errp, "Unsupported qcow2 feature(s): %s", features); > - g_free(features); > + error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); > + g_string_free(features, TRUE); > } > > /* -- Alex Bennée