user/sven/git.git/string-list.c, branch v2.49.0-rc2

global: mark code units that generate warnings with `-Wsign-compare`

2024-12-06T11:20:02Z

Mark code units that generate warnings with `-Wsign-compare`. This allows for a structured approach to get rid of all such warnings over time in a way that can be easily measured. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

git-compat-util: move alloc macros to git-compat-util.h

2023-07-05T18:42:31Z

alloc_nr, ALLOC_GROW, and ALLOC_GROW_BY are commonly used macros for dynamic array allocation. Moving these macros to git-compat-util.h with the other alloc macros focuses alloc.[ch] to allocation for Git objects and additionally allows us to remove inclusions to alloc.h from files that solely used the above macros. Signed-off-by: Calvin Wan Signed-off-by: Junio C Hamano

string-list: introduce `string_list_setlen()`

2023-04-24T23:01:28Z

It is sometimes useful to reduce the size of a `string_list`'s list of items without having to re-allocate them. For example, doing the following: struct strbuf buf = STRBUF_INIT; struct string_list parts = STRING_LIST_INIT_NO_DUP; while (strbuf_getline(&buf, stdin) != EOF) { parts.nr = 0; string_list_split_in_place(&parts, buf.buf, ":", -1); /* ... */ } string_list_clear(&parts, 0); is preferable over calling `string_list_clear()` on every iteration of the loop. This is because `string_list_clear()` causes us free our existing `items` array. This means that every time we call `string_list_split_in_place()`, the string-list internals re-allocate the same size array. Since in the above example we do not care about the individual parts after processing each line, it is much more efficient to pretend that there aren't any elements in the `string_list` by setting `list->nr` to 0 while leaving the list of elements allocated as-is. This allows `string_list_split_in_place()` to overwrite any existing entries without needing to free and re-allocate them. However, setting `list->nr` manually is not safe in all instances. There are a couple of cases worth worrying about: - If the `string_list` is initialized with `strdup_strings`, truncating the list can lead to overwriting strings which are allocated elsewhere. If there aren't any other pointers to those strings other than the ones inside of the `items` array, they will become unreachable and leak. (We could ourselves free the truncated items between string_list->items[nr] and `list->nr`, but no present or future callers would benefit from this additional complexity). - If the given `nr` is larger than the current value of `list->nr`, we'll trick the `string_list` into a state where it thinks there are more items allocated than there actually are, which can lead to undefined behavior if we try to read or write those entries. Guard against both of these by introducing a helper function which guards assignment of `list->nr` against each of the above conditions. Co-authored-by: Jeff King Signed-off-by: Jeff King Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano

string-list: multi-delimiter `string_list_split_in_place()`

2023-04-24T23:01:28Z

Enhance `string_list_split_in_place()` to accept multiple characters as delimiters instead of a single character. Instead of using `strchr(2)` to locate the first occurrence of the given delimiter character, `string_list_split_in_place_multi()` uses `strcspn(2)` to move past the initial segment of characters comprised of any characters in the delimiting set. When only a single delimiting character is provided, `strpbrk(2)` (which is implemented with `strcspn(2)`) has equivalent performance to `strchr(2)`. Modern `strcspn(2)` implementations treat an empty delimiter or the singleton delimiter as a special case and fall back to calling strchrnul(). Both glibc[1] and musl[2] implement `strcspn(2)` this way. This change is one step to removing `strtok(2)` from the tree. Note that `string_list_split_in_place()` is not a strict replacement for `strtok()`, since it will happily turn sequential delimiter characters into empty entries in the resulting string_list. For example: string_list_split_in_place(&xs, "foo:;:bar:;:baz", ":;", -1) would yield a string list of: ["foo", "", "", "bar", "", "", "baz"] Callers that wish to emulate the behavior of strtok(2) more directly should call `string_list_remove_empty_items()` after splitting. To avoid regressions for the new multi-character delimter cases, update t0063 in this patch as well. [1]: https://sourceware.org/git/?p=glibc.git;a=blob;f=string/strcspn.c;hb=glibc-2.37#l35 [2]: https://git.musl-libc.org/cgit/musl/tree/src/string/strcspn.c?h=v1.2.3#n11 Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano

alloc.h: move ALLOC_GROW() functions from cache.h

2023-02-24T01:25:28Z

This allows us to replace includes of cache.h with includes of the much smaller alloc.h in many places. It does mean that we also need to add includes of alloc.h in a number of C files. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

string-list: mark unused callback parameters

2022-10-18T04:24:04Z

String-lists may be used with callbacks for clearing or iteration. These callbacks need to conform to a particular interface, even though not every callback needs all of its parameters. Mark the unused ones to make -Wunused-parameter happy. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

string-list.[ch]: remove string_list_init() compatibility function

2021-09-28T21:43:38Z

Remove this function left over to accommodate in-flight changes, see 770fedaf9fb (string-list.[ch]: add a string_list_init_{nodup,dup}(), 2021-07-01) for the recent change to add "string_list_init_{nodup,dup}()" initializers. There was only one user of the API left in remote-curl.c. I don't know why I didn't include this change to remote-curl.c in bc40dfb10a0 (string-list.h users: change to use *_{nodup,dup}(), 2021-07-01), perhaps I just missed it. In any case, let's change that one user to use the new API, as of writing this there are no in-flight changes that use, so this seems like a good time to drop this before we get any new users of this compatibility API. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

string-list.[ch]: add a string_list_init_{nodup,dup}()

2021-07-01T19:32:22Z

In order to use the new "memcpy() a 'blank' struct on the stack" pattern for string_list_init(), and to make the macro initialization consistent with the function initialization introduce two new string_list_init_{nodup,dup}() functions. These are like the old string_list_init() when called with a false and true second argument, respectively. I think this not only makes things more consistent, but also easier to read. I often had to lookup what the ", 0)" or ", 1)" in these invocations meant, now it's right there in the function name, and corresponds to the macros. A subsequent commit will convert existing API users to this pattern, but as this is a very common API let's leave a compatibility function in place for later removal. This intermediate state also proves that the compatibility function works. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

style: the opening '{' of a function is in a separate line

2018-12-10T06:41:09Z

Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

Merge branch 'sb/string-list-remove-unused'

2018-09-24T17:30:50Z

Code clean-up. * sb/string-list-remove-unused: string-list: remove unused function print_string_list