git/bisect.c, branch v2.47.2

Merge branch 'ps/pack-refs-auto-heuristics'

2024-09-12T18:47:23Z

"git pack-refs --auto" for the files backend was too aggressive, which has been a bit tamed. * ps/pack-refs-auto-heuristics: refs/files: use heuristic to decide whether to repack with `--auto` t0601: merge tests for auto-packing of refs wrapper: introduce `log2u()`

wrapper: introduce `log2u()`

2024-09-04T15:03:24Z

We have an implementation of a function that computes the log2 for an integer. While we could instead use log2(3P), that involves floating point numbers and is thus needlessly complex and inefficient. We're about to add a second caller that wants to compute log2 for a `size_t`. Let's thus move the function into "wrapper.h" such that it becomes generally available. While at it, tweak the implementation a bit: - The parameter is converted from `int` to `uintmax_t`. This conversion is safe to do in "bisect.c" because we already check that the argument is positive. - The return value is an `unsigned`. It cannot ever be negative, so it is pointless for it to be a signed integer. - Loop until `!n` instead of requiring that `n > 1` and then subtract 1 from the result and add a special case for `!sz`. This helps compilers to generate more efficient code. Compilers recognize the pattern of this function and optimize accordingly. On GCC 14.2 x86_64: log2u(unsigned long): test rdi, rdi je .L3 bsr rax, rdi ret .L3: mov eax, -1 ret Clang 18.1 does not yet recognize the pattern, but starts to do so on Clang trunk x86_64. The code isn't quite as efficient as the one generated by GCC, but still manages to optimize away the loop: log2u(unsigned long): test rdi, rdi je .LBB0_1 shr rdi bsr rcx, rdi mov eax, 127 cmovne rax, rcx xor eax, -64 add eax, 65 ret .LBB0_1: mov eax, -1 ret The pattern is also recognized on other platforms like ARM64 GCC 14.2.0, where we end up using `clz`: log2u(unsigned long): clz x2, x0 cmp x0, 0 mov w1, 63 sub w0, w1, w2 csinv w0, w0, wzr, ne ret Note that we have a similar function `fastlog2()` in the reftable code. As that codebase is separate from the Git codebase we do not adapt it to use the new function. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs: add referent to each_ref_fn

2024-08-09T15:47:34Z

Add a parameter to each_ref_fn so that callers to the ref APIs that use this function as a callback can have acess to the unresolved value of a symbolic ref. Signed-off-by: John Cai Signed-off-by: Junio C Hamano

global: introduce `USE_THE_REPOSITORY_VARIABLE` macro

2024-06-14T17:26:33Z

Use of the `the_repository` variable is deprecated nowadays, and we slowly but steadily convert the codebase to not use it anymore. Instead, callers should be passing down the repository to work on via parameters. It is hard though to prove that a given code unit does not use this variable anymore. The most trivial case, merely demonstrating that there is no direct use of `the_repository`, is already a bit of a pain during code reviews as the reviewer needs to manually verify claims made by the patch author. The bigger problem though is that we have many interfaces that implicitly rely on `the_repository`. Introduce a new `USE_THE_REPOSITORY_VARIABLE` macro that allows code units to opt into usage of `the_repository`. The intent of this macro is to demonstrate that a certain code unit does not use this variable anymore, and to keep it from new dependencies on it in future changes, be it explicit or implicit For now, the macro only guards `the_repository` itself as well as `the_hash_algo`. There are many more known interfaces where we have an implicit dependency on `the_repository`, but those are not guarded at the current point in time. Over time though, we should start to add guards as required (or even better, just remove them). Define the macro as required in our code units. As expected, most of our code still relies on the global variable. Nearly all of our builtins rely on the variable as there is no way yet to pass `the_repository` to their entry point. For now, declare the macro in "biultin.h" to keep the required changes at least a little bit more contained. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

cocci: apply rules to rewrite callers of "refs" interfaces

2024-05-07T17:06:59Z

Apply the rules that rewrite callers of "refs" interfaces to explicitly pass `struct ref_store`. The resulting patch has been applied with the `--whitespace=fix` option. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

bisect: report the found commit with "show"

2024-04-15T18:29:09Z

When "git bisect" finds the first bad commit and shows it to the user, it calls "git diff-tree" to do so, whose output is meant to be stable and deliberately ignores end-user customizations. As the output is supposed to be consumed by humans, replace this with a call to "git show". This command honors configuration options (such as "log.date" and "log.mailmap") and other UI improvements (renames are detected). Pass some hard-coded options to "git show" to make the output similar to the one we are replacing, such as showing a patch summary only. Reported-by: Michael Osipov Signed-off-By: Peter Krefting Signed-off-by: Junio C Hamano

commit-reach(repo_get_merge_bases_many): pass on "missing commits" errors

2024-02-29T16:06:01Z

The `merge_bases_many()` function was just taught to indicate parsing errors, and now the `repo_get_merge_bases_many()` function is aware of that, too. Naturally, there are a lot of callers that need to be adjusted now, too. Next stop: `repo_get_merge_bases_dirty()`. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'js/check-null-from-read-object-file'

2024-02-14T23:36:06Z

The code paths that call repo_read_object_file() have been tightened to react to errors. * js/check-null-from-read-object-file: Always check the return value of `repo_read_object_file()`

Always check the return value of `repo_read_object_file()`

2024-02-06T18:42:28Z

There are a couple of places in Git's source code where the return value is not checked. As a consequence, they are susceptible to segmentation faults. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'en/header-cleanup'

2024-01-08T22:05:15Z

Remove unused header "#include". * en/header-cleanup: treewide: remove unnecessary includes in source files treewide: add direct includes currently only pulled in transitively trace2/tr2_tls.h: remove unnecessary include submodule-config.h: remove unnecessary include pkt-line.h: remove unnecessary include line-log.h: remove unnecessary include http.h: remove unnecessary include fsmonitor--daemon.h: remove unnecessary includes blame.h: remove unnecessary includes archive.h: remove unnecessary include treewide: remove unnecessary includes in source files treewide: remove unnecessary includes from header files