Re: [PATCH] builtins + test helpers: use return instead of exit() in cmd_*

[Phillip Wood <phillip.wood123@gmail.com>]

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
>