On 2022-Dec-19, Peter Eisentraut wrote:
> On 14.12.22 18:05, Justin Pryzby wrote:
> > On Wed, Dec 14, 2022 at 08:31:02AM +0100, Peter Eisentraut wrote:
> > > + return replace_percent_placeholders(base_command, "df", (const char
> > > *[]){target_detail, filename});
> >
> > This is a "compound literal", which I gather is required by C99.
> >
> > But I don't think that's currently being exercised, so I wonder if it's
> > going to break some BF members.
>
> We already use this, for example in pg_dump.
Yeah, we have this
#define ARCHIVE_OPTS(...) &(ArchiveOpts){__VA_ARGS__}
which we then use like this
ArchiveEntry(fout,
dbCatId, /* catalog ID */
dbDumpId, /* dump ID */
ARCHIVE_OPTS(.tag = datname,
.owner = dba,
.description = "DATABASE",
.section = SECTION_PRE_DATA,
.createStmt = creaQry->data,
.dropStmt = delQry->data));
I think the new one is not great. I wish we could do something more
straightforward, maybe like
replace_percent_placeholders(base_command,
PERCENT_OPT("f", filename),
PERCENT_OPT("d", target_detail));
Is there a performance disadvantage to a variadic implementation?
Alternatively, have all these macro calls form an array.
--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
Subversion to GIT: the shortest path to happiness I've ever heard of
(Alexey Klyukin)
