pre

#!/usr/bin/env sh
# compat: +ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh

pre() { ### @-
    ### dump all the `#define`s that `$CC $CPPFLAGS $CFLAGS $LDFLAGS` would result in.
    ###
    ### ```
    ### $ pre | shuf | head -n10
    ### #define __GNUC_MINOR__ 3
    ### #define __SIZEOF_LONG__ 4
    ### #define __UINT_LEAST16_TYPE__ short unsigned int
    ### #define __ORDER_BIG_ENDIAN__ 4321
    ### #define __SIZEOF_FLOAT__ 4
    ### #define __INTMAX_MAX__ 0x7fffffffffffffffLL
    ### #define __INT64_C(c) c ## LL
    ### #define __UINT16_MAX__ 0xffff
    ### #define __DEC64_MANT_DIG__ 16
    ### #define __DBL_HAS_INFINITY__ 1
    ### ```
    if [ -n "${ZSH_VERSION:-}" ]; then
        ${CC:-gcc} -dM -E - $=CPPFLAGS $=CFLAGS $=LDFLAGS < /dev/null
    else
        ${CC:-gcc} -dM -E - $CPPFLAGS $CFLAGS $LDFLAGS < /dev/null
    fi
}

[ -n "${preload+-}" ] || pre "$@"