# test-mergesort conflict with stdlib.h 5 messages from 2012-04-17 to 2012-04-17. Participants: Brian Gernhardt, Junio C Hamano. Thread: https://gitlist.dev/t/30265 ## Brian Gernhardt, 2012-04-17 17:25 Subject: test-mergesort conflict with stdlib.h Message-ID: URL: https://gitlist.dev/e/E6D295C2-C35E-4ECF-990D-FCF8407C2429%40gernhardtsoftware.com ``` On OS X 10.7.3, I get the following error attempting to build next: CC test-mergesort.o In file included from test-mergesort.c:2: ./mergesort.h:4:7: error: conflicting types for 'mergesort' void *mergesort(void *list, ^ /usr/include/stdlib.h:306:6: note: previous declaration is here int mergesort(void *, size_t, size_t, ^ This appears to be due to the fact that 0db71e0: "add mergesort() for linked lists" added a mergesort implementation with a different signature than a mergesort implemented by OS X's standard library. Perhaps git could use a less generic name like 'llist_mergesort'? ~~ Brian Gernhardt ``` ## Junio C Hamano, 2012-04-17 17:46 Subject: Re: test-mergesort conflict with stdlib.h Message-ID: <7vd376ntem.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vd376ntem.fsf%40alter.siamese.dyndns.org In-Reply-To: ``` Brian Gernhardt writes: > On OS X 10.7.3, I get the following error attempting to build next: > > CC test-mergesort.o > In file included from test-mergesort.c:2: > ./mergesort.h:4:7: error: conflicting types for 'mergesort' > void *mergesort(void *list, > ^ > /usr/include/stdlib.h:306:6: note: previous declaration is here > int mergesort(void *, size_t, size_t, > ^ > > This appears to be due to the fact that 0db71e0: "add mergesort() for > linked lists" added a mergesort implementation with a different > signature than a mergesort implemented by OS X's standard library. Unfortunate. OS X shouldn't contaminate the user namespace by adding such names in stdlib.h (which incidentally has qsort()), but the damage is done already, so I am not opposed to rename it to llist_mergesort() or something. ``` ## Brian Gernhardt, 2012-04-17 17:55 Subject: Re: test-mergesort conflict with stdlib.h Message-ID: URL: https://gitlist.dev/e/D6A62F9A-EB46-4736-BFDA-0044A993443E%40gernhardtsoftware.com In-Reply-To: <7vd376ntem.fsf@alter.siamese.dyndns.org> ``` On Apr 17, 2012, at 1:46 PM, Junio C Hamano wrote: > Unfortunate. OS X shouldn't contaminate the user namespace by adding such > names in stdlib.h (which incidentally has qsort()), but the damage is done > already, so I am not opposed to rename it to llist_mergesort() or something. This seems to be inherited from BSD's userspace which also has a mergesort (radixsort as well). I'll make a patch to rename it and if anyone doesn't like llist_mergesort, they can repaint the bikeshed themselves. ~~ Brian Gernhardt ``` ## Junio C Hamano, 2012-04-17 18:06 Subject: Re: test-mergesort conflict with stdlib.h Message-ID: <7v8vhunsg5.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7v8vhunsg5.fsf%40alter.siamese.dyndns.org In-Reply-To: <7vd376ntem.fsf@alter.siamese.dyndns.org> ``` Junio C Hamano writes: > Unfortunate. OS X shouldn't contaminate the user namespace by adding such > names in stdlib.h (which incidentally has qsort()), but the damage is done > already, so I am not opposed to rename it to llist_mergesort() or something. Something like this. While we are touching the code, let's add some documentation to the header. commit.c | 4 ++-- mergesort.c | 8 ++++---- mergesort.h | 16 ++++++++++++---- test-mergesort.c | 2 +- 4 files changed, 19 insertions(+), 11 deletions(-) diff --git a/commit.c b/commit.c index 0759b2c..84304c0 100644 --- a/commit.c +++ b/commit.c @@ -429,8 +429,8 @@ static void commit_list_set_next(void *a, void *next) void commit_list_sort_by_date(struct commit_list **list) { - *list = mergesort(*list, commit_list_get_next, commit_list_set_next, - commit_list_compare_by_date); + *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next, + commit_list_compare_by_date); } struct commit *pop_most_recent_commit(struct commit_list **list, diff --git a/mergesort.c b/mergesort.c index d084c60..e5fdf2e 100644 --- a/mergesort.c +++ b/mergesort.c @@ -23,10 +23,10 @@ static void *pop_item(struct mergesort_sublist *l, return p; } -void *mergesort(void *list, - void *(*get_next_fn)(const void *), - void (*set_next_fn)(void *, void *), - int (*compare_fn)(const void *, const void *)) +void *llist_mergesort(void *list, + void *(*get_next_fn)(const void *), + void (*set_next_fn)(void *, void *), + int (*compare_fn)(const void *, const void *)) { unsigned long l; diff --git a/mergesort.h b/mergesort.h index d6e5f4a..644cff1 100644 --- a/mergesort.h +++ b/mergesort.h @@ -1,9 +1,17 @@ #ifndef MERGESORT_H #define MERGESORT_H -void *mergesort(void *list, - void *(*get_next_fn)(const void *), - void (*set_next_fn)(void *, void *), - int (*compare_fn)(const void *, const void *)); +/* + * Sort linked list in place. + * - get_next_fn() returns the next element given an element of a linked list. + * - set_next_fn() takes two elements A and B, and makes B the "next" element + * of A on the list. + * - compare_fn() takes two elements A and B, and returns negative, 0, positive + * as the same sign as "subtracting" B from A. + */ +void *llist_mergesort(void *list, + void *(*get_next_fn)(const void *), + void (*set_next_fn)(void *, void *), + int (*compare_fn)(const void *, const void *)); #endif diff --git a/test-mergesort.c b/test-mergesort.c index 1dd82fd..3f388b4 100644 --- a/test-mergesort.c +++ b/test-mergesort.c @@ -42,7 +42,7 @@ int main(int argc, const char **argv) p = line; } - lines = mergesort(lines, get_next, set_next, compare_strings); + lines = llist_mergesort(lines, get_next, set_next, compare_strings); while (lines) { printf("%s", lines->text); ``` ## Brian Gernhardt, 2012-04-17 18:09 Subject: Re: test-mergesort conflict with stdlib.h Message-ID: <341E3693-9E1A-4356-A632-F5703E2829E8@gernhardtsoftware.com> URL: https://gitlist.dev/e/341E3693-9E1A-4356-A632-F5703E2829E8%40gernhardtsoftware.com In-Reply-To: <7v8vhunsg5.fsf@alter.siamese.dyndns.org> ``` On Apr 17, 2012, at 2:06 PM, Junio C Hamano wrote: > Junio C Hamano writes: > >> Unfortunate. OS X shouldn't contaminate the user namespace by adding such >> names in stdlib.h (which incidentally has qsort()), but the damage is done >> already, so I am not opposed to rename it to llist_mergesort() or something. > > Something like this. While we are touching the code, let's add some > documentation to the header. > > commit.c | 4 ++-- > mergesort.c | 8 ++++---- > mergesort.h | 16 ++++++++++++---- > test-mergesort.c | 2 +- > 4 files changed, 19 insertions(+), 11 deletions(-) This is basically identical to what I was going to send and it does, in fact, fix my build problem. Thanks, ~~ Brian Gernhardt ```