"Derrick Stolee via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > From: Derrick Stolee <derrickstolee@xxxxxxxxxx> > > The for_each_string_list_item() macro takes a string_list and > automatically constructs a for loop to iterate over its contents. This > macro will segfault if the list is non-NULL. > > We cannot change the macro to be careful around NULL values because > there are many callers that use the address of a local variable, which > will never be NULL and will cause compile errors with -Werror=address. > > For now, leave a documentation comment to try to avoid mistakes in the > future where a caller does not check for a NULL list. > > Signed-off-by: Derrick Stolee <derrickstolee@xxxxxxxxxx> > --- > string-list.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) For exactly the -Werror=address reason, any other way that checks list for NULL-ness cannot be done here (other than with Peff's inline helper that returns the first item or NULL), which is a bit of shame but this is totally outside the topic, and an additional comment is a good thing to have here. Thanks. All four patches look reasonable. Will queue (but after I make sure I can tag and push out -rc2 today). > diff --git a/string-list.h b/string-list.h > index d5a744e1438..c7b0d5d0008 100644 > --- a/string-list.h > +++ b/string-list.h > @@ -141,7 +141,12 @@ void string_list_clear_func(struct string_list *list, string_list_clear_func_t c > int for_each_string_list(struct string_list *list, > string_list_each_func_t func, void *cb_data); > > -/** Iterate over each item, as a macro. */ > +/** > + * Iterate over each item, as a macro. > + * > + * Be sure that 'list' is non-NULL. The macro cannot perform NULL > + * checks due to -Werror=address errors. > + */ > #define for_each_string_list_item(item,list) \ > for (item = (list)->items; \ > item && item < (list)->items + (list)->nr; \
