sizeof

来自「Nginx是一个高性能的HTTP和反向代理服务器」· 代码 · 共 83 行

# Copyright (C) Igor Sysoev


echo $ngx_n "checking for $ngx_type size ...$ngx_c"

cat << END >> $NGX_AUTOCONF_ERR

----------------------------------------
checking for $ngx_type size

END

ngx_size=

cat << END > $NGX_AUTOTEST.c

#include <sys/types.h>
#include <sys/time.h>
$NGX_INCLUDE_UNISTD_H
#include <signal.h>
#include <sys/resource.h>
$NGX_INCLUDE_INTTYPES_H
$NGX_INCLUDE_AUTO_CONFIG_H

int main() {
    printf("%d", sizeof($ngx_type));
    return 0;
}

END


ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT $ngx_feature_libs"

eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"


if [ -x $NGX_AUTOTEST ]; then
    ngx_size=`$NGX_AUTOTEST`
    echo " $ngx_size bytes"
fi


rm -f $NGX_AUTOTEST


case $ngx_size in
    4)
        if [ "$ngx_type"="long" ]; then
            ngx_max_value=2147483647L
        else
            ngx_max_value=2147483647
        fi

        ngx_max_len='(sizeof("-2147483648") - 1)'
    ;;

    8)
        if [ "$ngx_type"="long long" ]; then
            ngx_max_value=9223372036854775807LL
        else
            ngx_max_value=9223372036854775807L
        fi

        ngx_max_len='(sizeof("-9223372036854775808") - 1)'
    ;;

    *)
        echo
        echo "$0: error: can not detect $ngx_type size"

        echo "----------"    >> $NGX_AUTOCONF_ERR
        cat $NGX_AUTOTEST.c  >> $NGX_AUTOCONF_ERR
        echo "----------"    >> $NGX_AUTOCONF_ERR
        echo $ngx_test       >> $NGX_AUTOCONF_ERR
        echo "----------"    >> $NGX_AUTOCONF_ERR

        exit 1
esac