Re: [PATCH 04/18] Offer a function to demote fsck errors to warnings

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 23, 2014, 16:18 UTC
Message-ID: <xmqqr3vq49w5.fsf@gitster.dls.corp.google.com>
In-Reply-To: <alpine.DEB.1.00.1412231051320.21312@s15462909.onlinehome-server.info>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 5 quoted lines

> However, if we had to change the lookup such that it uses an array always,
> we would have to introduce a function to initialize the struct, always, in
> particular we would have to find a place to call that initialization
> function in, say, builtin/fsck.c (actually, in every code path that calls
> into the fsck machinery).

You would need to call a function to "initialize" the table if you support customization by reading the configuration files anyway. I am not sure why you think finding such a place is hard. Puzzled.

Also I suspect that you can tell the compiler to initialize the array in place with default values, perhaps like this?

-- >8 -- #include <stdio.h>

/* sorted by the default severity (lowest impact first) */
#define EVENT_LIST(F) \
	F(EVENT_A), \
	F(EVENT_B), \
	F(EVENT_C), \
	F(EVENT_D)

#define ID_(event) ID_ ## event
enum event_id {
	EVENT_LIST(ID_)
};

enum severity_level {
	severity_info, severity_warn, severity_error
};

/* below this one are INFO */ #define FIRST_WARN_EVENT_ID ID_EVENT_B /* below this one are WARN */ #define FIRST_ERROR_EVENT_ID ID_EVENT_C

#define STRING_(s) #s
#define DESC_(event) \
	{ \
		ID_ ## event, \
		STRING_(event), \
		(ID_ ## event < FIRST_WARN_EVENT_ID \
		? severity_info \
		: ID_ ## event < FIRST_ERROR_EVENT_ID \
		? severity_warn \
		: severity_error) \
	}

struct event_config {
	enum event_id id;
	const char * name;
	enum severity_level level;
} event[] = {
	EVENT_LIST(DESC_)
};

int main(int ac, char **av)
{
	int i;

	for (i = 0; i < sizeof(event) / sizeof(event[0]); i++) {
		printf("%d, %s, %d\n",
		       event[i].id, event[i].name, event[i].level);
	}
	return 0;
}