Compilation warnings on Centos, how to get rid of them?

[Technoken]

I'm currently having these warnings on Centos 6 when I recompile. But on windows I didn't get any warning

 

This warning is from the 'flag' at Shop to disable Discount & Overcharge

npc.c: In function ‘npc_parse_shop’:
npc.c:2674: warning: ‘id’ may be used uninitialized in this function

			nd->u.shop.count = 0;
			while ( p ) {
				unsigned short nameid2, qty = 0;
				int value;
LINE 2670			struct item_data* id;
				bool skip = false;
		
				if( p == NULL )
					break;
				switch(type) {
					case NPCTYPE_MARKETSHOP:
		#if PACKETVER >= 20131223
						if (sscanf(p, ",%6hu:%11d:%6hu", &nameid2, &value, &qty) != 3) {
							// Set shop flag [Cydh]
							if (nameid2 != 0) {
								ShowInfo("Shop at '"CL_WHITE"%s#L%d"CL_RESET"' Discount: "CL_WHITE"%s"CL_RESET", Overcharge: "CL_WHITE"%s"CL_RESET".\n",
									filepath, strline(buffer,start-buffer), nameid2&1 ? "NO" : "YES", nameid2&2 ? "NO" : "YES");
								nd->u.shop.flag = (unsigned char)nameid2;
							}
							if (!nd->u.shop.flag) {
								ShowError("npc_parse_shop: (MARKETSHOP) Invalid item definition in file '%s', line '%d'. Ignoring the rest of the line...\n * w1=%s\n * w2=%s\n * w3=%s\n * w4=%s\n", filepath, strline(buffer,start-buffer), w1, w2, w3, w4);
								skip = true;
							}
						}
		#endif
						break;
					default:
						if (sscanf(p, ",%6hu:%11d", &nameid2, &value) != 2) {
							// Set shop flag [Cydh]
							if (nameid2 != 0) {
								ShowInfo("Shop at '"CL_WHITE"%s#L%d"CL_RESET"' Discount: "CL_WHITE"%s"CL_RESET", Overcharge: "CL_WHITE"%s"CL_RESET".\n",
									filepath, strline(buffer,start-buffer), nameid2&1 ? "NO" : "YES", nameid2&2 ? "NO" : "YES");
								nd->u.shop.flag = (unsigned char)nameid2;
							}
							if (!nd->u.shop.flag) {
								ShowError("npc_parse_shop: Invalid item definition in file '%s', line '%d'. Ignoring the rest of the line...\n * w1=%s\n * w2=%s\n * w3=%s\n * w4=%s\n", filepath, strline(buffer,start-buffer), w1, w2, w3, w4);
								skip = true;
							}
						}
						break;
				}

 

This one is from  bOneShootOneKill mod

pc.c: In function ‘pc_bonus’:
pc.c:3105: warning: statement with no effect
pc.c: In function ‘pc_bonus2’:
pc.c:3804: warning: statement with no effect
pc.c:3818: warning: statement with no effect

3102		case SP_SUB_ONESHOOTONEKILL: // [Cydh]
3103			if (sd->state.lr_flag != 2) {
3104				sd->bonus.sub_oneshootonekill += val;
3105				cap_value(sd->bonus.sub_oneshootonekill,-10000,10000);
3106			}
3107			break;
//----------------------------------------------------------------------
3800			for (i = 0; i < len; i++) {
3801				if (sd->oneshootonekill_mob[i].mob_id == type2) {
3802					sd->oneshootonekill_mob[i].rate += val;
3803					isAdded = true;
3804					cap_value(sd->oneshootonekill_mob[i].rate, -10000, 10000);
3805					break;
3806				}
3807			}
//-------------------------------------------------------------------------
3816			sd->oneshootonekill_mob[i].mob_id = type2;
3817			sd->oneshootonekill_mob[i].rate = val;
3818			cap_value(sd->oneshootonekill_mob[i].rate, -10000, 10000);
3819		}

 

EDIT:

So here's what I did to get rid of these warnings

On npc.c, I replaced struct item_data* id; with struct item_data* id = itemdb_exists(nameid2);

and on pc.c I replaced these lines:

cap_value(sd->bonus.sub_oneshootonekill,-10000,10000); to sd->bonus.sub_oneshootonekill = cap_value(sd->bonus.sub_oneshootonekill,-10000,10000);

cap_value(sd->oneshootonekill_mob.rate, -10000, 10000); to sd->oneshootonekill_mob.rate = cap_value(sd->oneshootonekill_mob.rate, -10000, 10000);

I hope somehow could correct me if I did it wrong, since I just know little about src.

Edited February 20, 2017 by Technoken