I can currently see two warnings when compiling Zabbix. I included the 4.8 and the 4.7.2 warning messages:

4.8:

odbc.c: In function 'odbc_DBselect':
odbc.c:244:3: warning: passing argument 6 of 'SQLBindCol' from incompatible pointer type [enabled by default]
SQLBindCol(pdbh->hstmt, i + 1, SQL_C_CHAR, pdbh->row_data[i], MAX_STRING_LEN, &pdbh->data_len[i]);
^
In file included from ../../../include/zbxodbc.h:24:0,
from odbc.c:22:
/usr/include/sql.h:586:24: note: expected 'SQLLEN *' but argument is of type 'SQLINTEGER *'
SQLRETURN SQL_API SQLBindCol(SQLHSTMT StatementHandle,

4.7:

odbc.c: In function 'odbc_DBselect':
odbc.c:244:3: warning: passing argument 6 of 'SQLBindCol' from incompatible pointer type [enabled by default]
In file included from ../../../include/zbxodbc.h:24:0,
from odbc.c:22:
/usr/include/sql.h:586:24: note: expected 'SQLLEN *' but argument is of type 'SQLINTEGER *'

—

4.8:

fatal.c:23:0: warning: "_GNU_SOURCE" redefined [enabled by default]

1. define _GNU_SOURCE /* required for getting at program counter */
   ^
   <command-line>:0:0: note: this is the location of the previous definition

4.7:

fatal.c:23:0: warning: "_GNU_SOURCE" redefined [enabled by default]
<command-line>:0:0: note: this is the location of the previous definition