#
# SCons Largefile enablement
#
# Version 1.4
# 08-Jul-2024
#

def enableLargeFiles(check,conf):
    """Tries to enable 64-bit off_t on linux platform"""
    fseeko=conf.CheckFunc('fseeko')
    if fseeko:
        conf.env.Append(CPPFLAGS = '-DHAVE_FSEEKO')
    offt=conf.CheckTypeSize('off_t','#include <stdio.h>\n#include <sys/types.h>')
    ulong=conf.CheckTypeSize('unsigned long')
    if fseeko and offt<8 and offt>0:
        # we have off_t but its not 8 byte long
        saved_flags=conf.env.Dictionary()['CPPFLAGS']
        # we try to use some defs to make off_t longer
        conf.env.Append(CPPFLAGS='-D_FILE_OFFSET_BITS=64')
        offt=conf.CheckTypeSize('off_t','#include <stdio.h>\n#include <sys/types.h>')
        if offt < 8:
              env.Replace(CPPFLAGS=saved_flags)
    if not fseeko:
        # no fseeko we do not need off_t for anything
        offt = 0
    check.Message("Checking for effective size of off_t ... ")
    check.Result(str(offt)+" bytes")
    conf.env.Append(CPPFLAGS = '-DSIZEOF_OFF_T='+str(offt))
    check.Message("Checking if we have native large files ... ")
    if fseeko and int(offt)>=8 and int(ulong)>=8:
       conf.env.Append(CPPFLAGS = '-DNATIVE_LARGEFILES')
       rc=True
    else:
       rc=False
    check.Result(rc)