Re: [PATCH 06/21] convert manual allocations to argv_array

On Sat, Feb 20, 2016 at 03:29:29AM -0500, Eric Sunshine wrote:

On Sat, Feb 20, 2016 at 3:10 AM, Jeff King [off-list ref] wrote:

quoted

On Sat, Feb 20, 2016 at 03:07:00AM -0500, Eric Sunshine wrote:

quoted

quoted

+               /* argv strings are now owned by pathspec */
+               paths.argc = 0;
+               argv_array_clear(&paths);

This overly intimate knowledge of the internal implementation of
argv_array_clear() is rather ugly.

Yep, I agree. Suggestions?

We can just leak the array of "char *". This function is called only
once per program invocation, and that's unlikely to change.

I guess we can make an argv_array_detach_strings() function. Or maybe
even just argv_array_detach() would be less gross, and then this
function could manually free the array but not the strings themselves.

The latter is what I was thinking, and I agree that
argv_array_detach() would be less gross than
argv_array_detach_strings(), however, it also feels a bit wrong since
this sort of ownership transfer is kind of out of scope for
argv_array.

I wonder if a simple "dup'ing" string_list would be more suitable for
this case. You'd have to append the NULL item manually with
string_list_append_nodup(), and string_list_clear() would then be the
correct way to dispose of the list without intimate knowledge of its
implementation and no need for an API extension.

A string_list doesn't just store pointers; it's a struct with a util
field. So you can't pass it to things expecting a "const char **".

I think argv_array_detach() is the least-bad thing here. It matches
strbuf_detach() to say "you now own the storage" (as opposed to just
peeking at argv.argv, which we should do only in a read-only way).

-Peff