| Message ID | 8faa0cd5-25e8-4a8f-ad8b-5fc1b6e5138b@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | checkout: plug some leaks in git-restore | expand |
Rubén Justo <rjusto@gmail.com> writes: > In git-restore we need to free the pathspec and pathspec_from_file > values from the struct checkout_opts. > > A simple fix could be to free them in cmd_restore, after the call to > checkout_main returns, like we are doing [1][2] in the sibling function > cmd_checkout. > > However, we can do better. Quite honestly, my knee-jerk raction against _main_1() was "Yuck". If the repetition of "here are the things we need to clean up" shared in the current checkout_main() looks so disturbing, I would have gone in the opposite direction: the current callers of _main() will do these clean-up actions after the call to _main() returns, so bundle them into a helper function and call it from the callers of _main(), without introducing an extra layer of opacity, and I would have thought that would be what we would call "doing better". Even better, shouldn't you be able to do much better by not doing the _main_1() thing at all? If you look at checkout_main(), the only way to leave thsi function, aside from die()'s, are "return" statements to the caller at the very end of the function. You should be able to, instead of returning, capture the value you receive from calling either checkout_paths() or checkout_branch(), and then do the common "clean-up" you stole from existing calls and moved into _main_1(), and after doing so, return the value you captured from one of these calls that used to directly return, no? Perhaps something along this line, which should be an equilvalent to what your patch did? builtin/checkout.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git c/builtin/checkout.c w/builtin/checkout.c index 15293a3013..a8ccdfa1f2 100644 --- c/builtin/checkout.c +++ w/builtin/checkout.c @@ -1706,6 +1706,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix, struct branch_info *new_branch_info) { int parseopt_flags = 0; + int retval; opts->overwrite_ignore = 1; opts->prefix = prefix; @@ -1900,9 +1901,16 @@ static int checkout_main(int argc, const char **argv, const char *prefix, } if (opts->patch_mode || opts->pathspec.nr) - return checkout_paths(opts, new_branch_info); + retval = checkout_paths(opts, new_branch_info); else - return checkout_branch(opts, new_branch_info); + retval = checkout_branch(opts, new_branch_info); + + branch_info_release(new_branch_info); + clear_pathspec(&opts->pathspec); + free(opts->pathspec_from_file); + FREE_AND_NULL(options); + + return retval; } int cmd_checkout(int argc, const char **argv, const char *prefix) @@ -1953,10 +1961,6 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) ret = checkout_main(argc, argv, prefix, &opts, options, checkout_usage, &new_branch_info); - branch_info_release(&new_branch_info); - clear_pathspec(&opts.pathspec); - free(opts.pathspec_from_file); - FREE_AND_NULL(options); return ret; } @@ -1997,8 +2001,6 @@ int cmd_switch(int argc, const char **argv, const char *prefix) ret = checkout_main(argc, argv, prefix, &opts, options, switch_branch_usage, &new_branch_info); - branch_info_release(&new_branch_info); - FREE_AND_NULL(options); return ret; } @@ -2036,7 +2038,5 @@ int cmd_restore(int argc, const char **argv, const char *prefix) ret = checkout_main(argc, argv, prefix, &opts, options, restore_usage, &new_branch_info); - branch_info_release(&new_branch_info); - FREE_AND_NULL(options); return ret; } [Footnote] It is somewhat funny that we are moving more things into the checkout_main() common function. Maybe the true culprit of this mess was that the approach for splitting "switch" and "restore" out of "checkout" was misdesigned. People were so loudly against "checkout" that can check out a branch, or check out files and directories out of a commit, and that was why these two separate commands to do these two separate things were created. But instead of two separate functions that do two separate and unrelated things, and making "checkout" call either one of these depending on which one of the two separate things it is asked to do, we ended up in a state where a single function _main() is shared among the three, which may have solved the "these two are separate operations and having them crammed together into one command is confusing from the user's point of view" complaint, but these two operations are still tightly coupled. The fact that the things that need to be cleaned up after calling checkout_paths() and checkout_branch() are identical is quite telling ;-)
diff --git a/builtin/checkout.c b/builtin/checkout.c index 4fe049cf37..2ff4cf88a6 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -1702,10 +1702,10 @@ static struct option *add_checkout_path_options(struct checkout_opts *opts, /* create-branch option (either b or c) */ static char cb_option = 'b'; -static int checkout_main(int argc, const char **argv, const char *prefix, - struct checkout_opts *opts, struct option *options, - const char * const usagestr[], - struct branch_info *new_branch_info) +static int checkout_main_1(int argc, const char **argv, const char *prefix, + struct checkout_opts *opts, struct option *options, + const char * const usagestr[], + struct branch_info *new_branch_info) { int parseopt_flags = 0; @@ -1907,6 +1907,20 @@ static int checkout_main(int argc, const char **argv, const char *prefix, return checkout_branch(opts, new_branch_info); } +static int checkout_main(int argc, const char **argv, const char *prefix, + struct checkout_opts *opts, struct option *options, + const char * const usagestr[]) +{ + struct branch_info new_branch_info = { 0 }; + int ret = checkout_main_1(argc, argv, prefix, opts, options, + checkout_usage, &new_branch_info); + branch_info_release(&new_branch_info); + clear_pathspec(&opts->pathspec); + free(opts->pathspec_from_file); + free(options); + return ret; +} + int cmd_checkout(int argc, const char **argv, const char *prefix) { struct checkout_opts opts; @@ -1922,8 +1936,6 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")), OPT_END() }; - int ret; - struct branch_info new_branch_info = { 0 }; memset(&opts, 0, sizeof(opts)); opts.dwim_new_local_branch = 1; @@ -1953,13 +1965,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) options = add_common_switch_branch_options(&opts, options); options = add_checkout_path_options(&opts, options); - ret = checkout_main(argc, argv, prefix, &opts, - options, checkout_usage, &new_branch_info); - branch_info_release(&new_branch_info); - clear_pathspec(&opts.pathspec); - free(opts.pathspec_from_file); - FREE_AND_NULL(options); - return ret; + return checkout_main(argc, argv, prefix, &opts, options, + checkout_usage); } int cmd_switch(int argc, const char **argv, const char *prefix) @@ -1977,8 +1984,6 @@ int cmd_switch(int argc, const char **argv, const char *prefix) N_("throw away local modifications")), OPT_END() }; - int ret; - struct branch_info new_branch_info = { 0 }; memset(&opts, 0, sizeof(opts)); opts.dwim_new_local_branch = 1; @@ -1997,11 +2002,8 @@ int cmd_switch(int argc, const char **argv, const char *prefix) cb_option = 'c'; - ret = checkout_main(argc, argv, prefix, &opts, - options, switch_branch_usage, &new_branch_info); - branch_info_release(&new_branch_info); - FREE_AND_NULL(options); - return ret; + return checkout_main(argc, argv, prefix, &opts, options, + switch_branch_usage); } int cmd_restore(int argc, const char **argv, const char *prefix) @@ -2020,8 +2022,6 @@ int cmd_restore(int argc, const char **argv, const char *prefix) OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")), OPT_END() }; - int ret; - struct branch_info new_branch_info = { 0 }; memset(&opts, 0, sizeof(opts)); opts.accept_ref = 0; @@ -2036,9 +2036,6 @@ int cmd_restore(int argc, const char **argv, const char *prefix) options = add_common_options(&opts, options); options = add_checkout_path_options(&opts, options); - ret = checkout_main(argc, argv, prefix, &opts, - options, restore_usage, &new_branch_info); - branch_info_release(&new_branch_info); - FREE_AND_NULL(options); - return ret; + return checkout_main(argc, argv, prefix, &opts, options, + restore_usage); } diff --git a/t/t2070-restore.sh b/t/t2070-restore.sh index 16d6348b69..ac404945d4 100755 --- a/t/t2070-restore.sh +++ b/t/t2070-restore.sh @@ -5,6 +5,7 @@ test_description='restore basic functionality' GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh test_expect_success 'setup' ' diff --git a/t/t2071-restore-patch.sh b/t/t2071-restore-patch.sh index 27e85be40a..42d5522119 100755 --- a/t/t2071-restore-patch.sh +++ b/t/t2071-restore-patch.sh @@ -2,6 +2,7 @@ test_description='git restore --patch' +TEST_PASSES_SANITIZE_LEAK=true . ./lib-patch-mode.sh test_expect_success 'setup' ' diff --git a/t/t2072-restore-pathspec-file.sh b/t/t2072-restore-pathspec-file.sh index 8198a1e578..86c9c88788 100755 --- a/t/t2072-restore-pathspec-file.sh +++ b/t/t2072-restore-pathspec-file.sh @@ -2,6 +2,7 @@ test_description='restore --pathspec-from-file' +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh test_tick diff --git a/t/t6418-merge-text-auto.sh b/t/t6418-merge-text-auto.sh index 41288a60ce..48a62cb855 100755 --- a/t/t6418-merge-text-auto.sh +++ b/t/t6418-merge-text-auto.sh @@ -15,6 +15,7 @@ test_description='CRLF merge conflict across text=auto change GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh test_have_prereq SED_STRIPS_CR && SED_OPTIONS=-b
In git-restore we need to free the pathspec and pathspec_from_file values from the struct checkout_opts. A simple fix could be to free them in cmd_restore, after the call to checkout_main returns, like we are doing [1][2] in the sibling function cmd_checkout. However, we can do better. We have git-switch and git-restore, both of them spin-offs[3][4] of git-checkout. All three are implemented as thin wrappers around checkout_main. Considering this, it makes a lot of sense to do the cleanup closer to checkout_main. Factor out the call to checkout_main in a function that does both the work and the cleanup, and use it in the three wrappers. As a consequence, mark: t2070, t2071, t2072 and t6418 as leak-free. [1] 9081a421a6 (checkout: fix "branch info" memory leaks, 2021-11-16) [2] 7ce4088ab7 (parse-options: consistently allocate memory in fix_filename(), 2023-03-04) [3] d787d311db (checkout: split part of it to new command 'switch', 2019-03-29) [4] 46e91b663b (checkout: split part of it to new command 'restore', 2019-04-25) Signed-off-by: Rubén Justo <rjusto@gmail.com> --- Range-diff: 1: d54a2c4dcc ! 1: 78ad33fa02 checkout: plug some leaks in git-restore @@ Commit message [4] 46e91b663b (checkout: split part of it to new command 'restore', 2019-04-25) + Signed-off-by: Rubén Justo <rjusto@gmail.com> + ## builtin/checkout.c ## @@ builtin/checkout.c: static struct option *add_checkout_path_options(struct checkout_opts *opts, /* create-branch option (either b or c) */ Thanks Eric. builtin/checkout.c | 51 +++++++++++++++----------------- t/t2070-restore.sh | 1 + t/t2071-restore-patch.sh | 1 + t/t2072-restore-pathspec-file.sh | 1 + t/t6418-merge-text-auto.sh | 1 + 5 files changed, 28 insertions(+), 27 deletions(-)