Subject: Re: [PATCH v9 5/8] config: add `git_die_config()` to the config-set API

From: Junio C Hamano <[email-masked]>
Date: Thu, 07 Aug 2014 11:55:25 -0700

Tanay Abhra <[email-masked]> writes:

> diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt
> index 21f280c..0d8b99b 100644
> --- a/Documentation/technical/api-config.txt
> +++ b/Documentation/technical/api-config.txt
> @@ -155,6 +155,19 @@ as well as retrieval for the queried variable, including:
>  	Similar to `git_config_get_string`, but expands `~` or `~user` into
>  	the user's home directory when found at the beginning of the path.
>  
> +`git_die_config(const char *key, const char *err, ...)`::
> +
> +	First prints the error message specified by the caller in `err` and then
> +	dies printing the line number and the file name of the highest priority
> +	value for the configuration variable `key`.

Reviewed with a wider context, I notice that this entry alone lacks
the return type.  I am assuming that this is just an oversight, and
adding 'void ' in front of the filename to match the next entry is
simple enough.

> +`void git_die_config_linenr(const char *key, const char *filename, int linenr)`::
> + ...
> +extern NORETURN void git_die_config(const char *key, const char *err, ...) __attribute__((format(printf, 2, 3)));
> ...
> +NORETURN __attribute__((format(printf, 2, 3)))
> +void git_die_config(const char *key, const char *err, ...)
> +{

My first reaction was that it might make the compiler unhappy to
declare that the "err" is a printf-like format string and then to
allow some callers to pass NULL to the function.  My build however
does not seem to complain, so perhaps this is OK.

> +	const struct string_list *values;
> +	struct key_value_info *kv_info;
> +
> +	if (err) {
> +		va_list params;
> +		va_start(params, err);
> +		vreportf("error: ", err, params);
> +		va_end(params);
> +	}
> +	values = git_config_get_value_multi(key);
> +	kv_info = values->items[values->nr - 1].util;
> +	git_die_config_linenr(key, kv_info->filename, kv_info->linenr);
>  }
>  
>  /*