| Message ID | patch-1.1-61d7e6e079-20210607T111008Z-avarab@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | builtins + test helpers: use return instead of exit() in cmd_* | expand |
Ævar Arnfjörð Bjarmason wrote: > Change various cmd_* functions to use "return" instead of exit() to > indicate an exit code. On Solaris with SunCC the compiler legitimately > complains about these, since we'll e.g. skip the cleanup (e.g. closing > fd's, erroring if we can't) in git.c's run_builtin() when we exit() > directly like this. > > Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Makes sense to me and it's obviously correct. Reviewed-by: Felipe Contreras <felipe.contreras@gmail.com>
On Mon, Jun 07, 2021 at 01:12:48PM +0200, Ævar Arnfjörð Bjarmason wrote: > Change various cmd_* functions to use "return" instead of exit() to > indicate an exit code. On Solaris with SunCC the compiler legitimately > complains about these, since we'll e.g. skip the cleanup (e.g. closing > fd's, erroring if we can't) in git.c's run_builtin() when we exit() > directly like this. Each of these cases looks like a simple and obvious conversion, and I certainly don't mind us doing it. But I do wonder what SunCC is complaining about exactly. Calling exit() means you don't have to worry about cleanup anymore. Does the compiler not have any notion of NORETURN or equivalent? If so, I'd expect many more complaints in general that we probably _won't_ want to silence, because it will be awkward to do so. > diff --git a/builtin/difftool.c b/builtin/difftool.c > index 89334b77fb..6a9242a803 100644 > --- a/builtin/difftool.c > +++ b/builtin/difftool.c > @@ -675,7 +675,7 @@ static int run_file_diff(int prompt, const char *prefix, > "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, > NULL > }; > - int ret = 0, i; > + int i; > > if (prompt > 0) > env[2] = "GIT_DIFFTOOL_PROMPT=true"; > @@ -686,8 +686,7 @@ static int run_file_diff(int prompt, const char *prefix, > strvec_push(&args, "diff"); > for (i = 0; i < argc; i++) > strvec_push(&args, argv[i]); > - ret = run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); > - exit(ret); > + return run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); > } This one I'm not surprised that a compiler would complain about. The function returns an int, but there are no return paths from the function (and hence the caller doing "return run_diff_files()" likewise could not ever return there. Which is not quite what you said it complained about above, hence my curiosity. :) -Peff
On Tue, Jun 08 2021, Jeff King wrote: > On Mon, Jun 07, 2021 at 01:12:48PM +0200, Ævar Arnfjörð Bjarmason wrote: > >> Change various cmd_* functions to use "return" instead of exit() to >> indicate an exit code. On Solaris with SunCC the compiler legitimately >> complains about these, since we'll e.g. skip the cleanup (e.g. closing >> fd's, erroring if we can't) in git.c's run_builtin() when we exit() >> directly like this. > > Each of these cases looks like a simple and obvious conversion, and I > certainly don't mind us doing it. > > But I do wonder what SunCC is complaining about exactly. Calling exit() > means you don't have to worry about cleanup anymore. Does the compiler > not have any notion of NORETURN or equivalent? If so, I'd expect many > more complaints in general that we probably _won't_ want to silence, > because it will be awkward to do so. It does, but in this case there's no NORETURN and we declared the command to return int, and it's not the "main" function. I believe that's what trips it up, as noted in a v2 I just submitted now: https://lore.kernel.org/git/patch-1.1-f225b78e01-20210608T104454Z-avarab@gmail.com/ It's not whining about every instance of "exit" in the codebase. >> diff --git a/builtin/difftool.c b/builtin/difftool.c >> index 89334b77fb..6a9242a803 100644 >> --- a/builtin/difftool.c >> +++ b/builtin/difftool.c >> @@ -675,7 +675,7 @@ static int run_file_diff(int prompt, const char *prefix, >> "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, >> NULL >> }; >> - int ret = 0, i; >> + int i; >> >> if (prompt > 0) >> env[2] = "GIT_DIFFTOOL_PROMPT=true"; >> @@ -686,8 +686,7 @@ static int run_file_diff(int prompt, const char *prefix, >> strvec_push(&args, "diff"); >> for (i = 0; i < argc; i++) >> strvec_push(&args, argv[i]); >> - ret = run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >> - exit(ret); >> + return run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >> } > > This one I'm not surprised that a compiler would complain about. The > function returns an int, but there are no return paths from the > function (and hence the caller doing "return run_diff_files()" likewise > could not ever return there. Which is not quite what you said it > complained about above, hence my curiosity. :) I sent a few miscellaneous fixes recently for 15-20 SunCC warnings. Around 1/2 of these are legitimate issues like these, the rest are bugs in SunCC or flaws in it flow analysis or other known bugs in the compiler.
On 08/06/2021 07:49, Jeff King wrote: > On Mon, Jun 07, 2021 at 01:12:48PM +0200, Ævar Arnfjörð Bjarmason wrote: > >> Change various cmd_* functions to use "return" instead of exit() to >> indicate an exit code. On Solaris with SunCC the compiler legitimately >> complains about these, since we'll e.g. skip the cleanup (e.g. closing >> fd's, erroring if we can't) in git.c's run_builtin() when we exit() >> directly like this. > > Each of these cases looks like a simple and obvious conversion, and I > certainly don't mind us doing it. > > But I do wonder what SunCC is complaining about exactly. Calling exit() > means you don't have to worry about cleanup anymore. Does the compiler > not have any notion of NORETURN or equivalent? If so, I'd expect many > more complaints in general that we probably _won't_ want to silence, > because it will be awkward to do so. It is curious that is only complaining abut exit() calls and not die(), maybe that is just a coincidence though if it is not complaining about all calls to exit() Best Wishes Phillip >> diff --git a/builtin/difftool.c b/builtin/difftool.c >> index 89334b77fb..6a9242a803 100644 >> --- a/builtin/difftool.c >> +++ b/builtin/difftool.c >> @@ -675,7 +675,7 @@ static int run_file_diff(int prompt, const char *prefix, >> "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, >> NULL >> }; >> - int ret = 0, i; >> + int i; >> >> if (prompt > 0) >> env[2] = "GIT_DIFFTOOL_PROMPT=true"; >> @@ -686,8 +686,7 @@ static int run_file_diff(int prompt, const char *prefix, >> strvec_push(&args, "diff"); >> for (i = 0; i < argc; i++) >> strvec_push(&args, argv[i]); >> - ret = run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >> - exit(ret); >> + return run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >> } > > This one I'm not surprised that a compiler would complain about. The > function returns an int, but there are no return paths from the > function (and hence the caller doing "return run_diff_files()" likewise > could not ever return there. Which is not quite what you said it > complained about above, hence my curiosity. :) > > -Peff >
On Thu, Jun 10 2021, Phillip Wood wrote: > On 08/06/2021 07:49, Jeff King wrote: >> On Mon, Jun 07, 2021 at 01:12:48PM +0200, Ævar Arnfjörð Bjarmason wrote: >> >>> Change various cmd_* functions to use "return" instead of exit() to >>> indicate an exit code. On Solaris with SunCC the compiler legitimately >>> complains about these, since we'll e.g. skip the cleanup (e.g. closing >>> fd's, erroring if we can't) in git.c's run_builtin() when we exit() >>> directly like this. >> Each of these cases looks like a simple and obvious conversion, and >> I >> certainly don't mind us doing it. >> But I do wonder what SunCC is complaining about exactly. Calling >> exit() >> means you don't have to worry about cleanup anymore. Does the compiler >> not have any notion of NORETURN or equivalent? If so, I'd expect many >> more complaints in general that we probably _won't_ want to silence, >> because it will be awkward to do so. > > It is curious that is only complaining abut exit() calls and not > die(), maybe that is just a coincidence though if it is not > complaining about all calls to exit() It's "function has no return statement", usually things that die() will also return if nothing goes wrong. It also complains about e.g. cram() in imap-send.c under NO_OPENSSL=Y, which is an "non-void" returning function stub that just calls die(). I recall raising that on-list in the past and proposing that they have a dummy return value, but that met lukewarm support, so I just consider them false alarms and try to ignore them. I do think we should have "die_report" or whatever versions of die() so you could do: return die_report(...); You can do that with error(), but that means changing the error message from "fatal:" to "error:". Those cases are obscure though, e.g. piping to a full disk where we'd die for other reasons. Now we'll hide that error. I mean, we'd do so anyway since cmd_builtin() in git.c won't reach the "closing fd's" check, but that could be fixed, and there's other similar cases where we needlessly conflate the desire to say "fatal" and exit with 128 with returning an error and doing cleanup etc. >>> diff --git a/builtin/difftool.c b/builtin/difftool.c >>> index 89334b77fb..6a9242a803 100644 >>> --- a/builtin/difftool.c >>> +++ b/builtin/difftool.c >>> @@ -675,7 +675,7 @@ static int run_file_diff(int prompt, const char *prefix, >>> "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, >>> NULL >>> }; >>> - int ret = 0, i; >>> + int i; >>> if (prompt > 0) >>> env[2] = "GIT_DIFFTOOL_PROMPT=true"; >>> @@ -686,8 +686,7 @@ static int run_file_diff(int prompt, const char *prefix, >>> strvec_push(&args, "diff"); >>> for (i = 0; i < argc; i++) >>> strvec_push(&args, argv[i]); >>> - ret = run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >>> - exit(ret); >>> + return run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); >>> } >> This one I'm not surprised that a compiler would complain about. The >> function returns an int, but there are no return paths from the >> function (and hence the caller doing "return run_diff_files()" likewise >> could not ever return there. Which is not quite what you said it >> complained about above, hence my curiosity. :) >> -Peff >>
diff --git a/builtin/difftool.c b/builtin/difftool.c index 89334b77fb..6a9242a803 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -675,7 +675,7 @@ static int run_file_diff(int prompt, const char *prefix, "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, NULL }; - int ret = 0, i; + int i; if (prompt > 0) env[2] = "GIT_DIFFTOOL_PROMPT=true"; @@ -686,8 +686,7 @@ static int run_file_diff(int prompt, const char *prefix, strvec_push(&args, "diff"); for (i = 0; i < argc; i++) strvec_push(&args, argv[i]); - ret = run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); - exit(ret); + return run_command_v_opt_cd_env(args.v, RUN_GIT_CMD, prefix, env); } int cmd_difftool(int argc, const char **argv, const char *prefix) diff --git a/builtin/merge-ours.c b/builtin/merge-ours.c index 4594507420..a745c32ae4 100644 --- a/builtin/merge-ours.c +++ b/builtin/merge-ours.c @@ -29,5 +29,5 @@ int cmd_merge_ours(int argc, const char **argv, const char *prefix) die_errno("read_cache failed"); if (index_differs_from(the_repository, "HEAD", NULL, 0)) exit(2); - exit(0); + return 0; } diff --git a/builtin/mktree.c b/builtin/mktree.c index 891991b00d..ae78ca1c02 100644 --- a/builtin/mktree.c +++ b/builtin/mktree.c @@ -189,5 +189,5 @@ int cmd_mktree(int ac, const char **av, const char *prefix) used=0; /* reset tree entry buffer for re-use in batch mode */ } strbuf_release(&sb); - exit(0); + return 0; } diff --git a/t/helper/test-hash-speed.c b/t/helper/test-hash-speed.c index 432233c7f0..f40d9ad0c2 100644 --- a/t/helper/test-hash-speed.c +++ b/t/helper/test-hash-speed.c @@ -57,5 +57,5 @@ int cmd__hash_speed(int ac, const char **av) free(p); } - exit(0); + return 0; } diff --git a/t/helper/test-hash.c b/t/helper/test-hash.c index 0a31de66f3..261c545b9d 100644 --- a/t/helper/test-hash.c +++ b/t/helper/test-hash.c @@ -54,5 +54,5 @@ int cmd_hash_impl(int ac, const char **av, int algo) fwrite(hash, 1, algop->rawsz, stdout); else puts(hash_to_hex_algop(hash, algop)); - exit(0); + return 0; } diff --git a/t/helper/test-match-trees.c b/t/helper/test-match-trees.c index b9fd427571..4079fdee06 100644 --- a/t/helper/test-match-trees.c +++ b/t/helper/test-match-trees.c @@ -23,5 +23,5 @@ int cmd__match_trees(int ac, const char **av) shift_tree(the_repository, &one->object.oid, &two->object.oid, &shifted, -1); printf("shifted: %s\n", oid_to_hex(&shifted)); - exit(0); + return 0; } diff --git a/t/helper/test-reach.c b/t/helper/test-reach.c index cda804ed79..2f65c7f6a5 100644 --- a/t/helper/test-reach.c +++ b/t/helper/test-reach.c @@ -166,5 +166,5 @@ int cmd__reach(int ac, const char **av) print_sorted_commit_ids(list); } - exit(0); + return 0; }
Change various cmd_* functions to use "return" instead of exit() to indicate an exit code. On Solaris with SunCC the compiler legitimately complains about these, since we'll e.g. skip the cleanup (e.g. closing fd's, erroring if we can't) in git.c's run_builtin() when we exit() directly like this. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> --- A trivial issue noticed in my pre-v2.32.0 testing that I wanted to leave until after the release. builtin/difftool.c | 5 ++--- builtin/merge-ours.c | 2 +- builtin/mktree.c | 2 +- t/helper/test-hash-speed.c | 2 +- t/helper/test-hash.c | 2 +- t/helper/test-match-trees.c | 2 +- t/helper/test-reach.c | 2 +- 7 files changed, 8 insertions(+), 9 deletions(-)