make-trampolines

#!/bin/bash

printf "#include \"platform.h\"\n"
printf "#define bool _Bool\n\n"

explain_type='
remaining=1
typ=""
tagName=""
tag=""
while (( $remaining > 0 )); do
    remaining=$(($remaining-1))
    head=$1
    shift
    case $head in
    p)
        typ="$typ pointer to void"
        ;;
    v)
        typ="$typ void"
        ;;
    sc)
        typ="$typ signed char"
        ;;
    b)
        typ="$typ bool"
        ;;
    uc)
        typ="$typ unsigned char"
        ;;
    us)
        typ="$typ unsigned short"
        ;;
    ui)
        typ="$typ unsigned int"
        ;;
    ul)
        typ="$typ unsigned long"
        ;;
    ull)
        typ="$typ unsigned long long"
        ;;
    ss)
        typ="$typ short"
        ;;
    si)
        typ="$typ int"
        ;;
    sl)
        typ="$typ long"
        ;;
    ll)
        typ="$typ long long"
        ;;
    f)
        typ="$typ float"
        ;;
    d)
        typ="$typ double"
        ;;
    ld)
        typ="$typ long double"
        ;;
    cf)
        typ="$typ float complex"
        ;;
    cd)
        typ="$typ double complex"
        ;;
    cld)
        typ="$typ long double complex"
        ;;
    a)
        remaining=$((remaining+1))
        typ="$typ _Atomic"
        ;;
    [su][0-9]*)
        nfields=${head#[su]}
        sremaining=$nfields
        tagName="$head"
        while (( $sremaining > 0 )); do
            shead=$1
            shift
            IFS="$OIFS"
            tagName="${tagName}_${shead}"
            IFS="_ "
            case $shead in
                [su][0-9]*)
                    snfields=${shead#?}
                    sremaining=$(($sremaining+$snfields))
                    ;;
            esac
            sremaining=$(($sremaining-1))
        done
        tag="struct"
        if [[ $head =~ ^u ]]; then tag="union"; fi
        typ="$typ $tag __$tagName"
    esac
done
'

function explain_args {
    local nfixed=$1
    shift
    local conn=""
    while (( $nfixed > 0 )); do
        printf "$conn$1"
        shift
        conn=", "
        nfixed=$((nfixed - 1))
    done
}

function explain_fun_type {
    printf "pointer to function ("
    eval "$explain_type"
    local return_type="$typ"
    local conn=""
    arg_types=""
    if [ $# -eq 2 ]; then
        printf "void"
    else
        while (( "$#" > 2 )); do
            eval "$explain_type"
            arg_types="$arg_types$conn$typ"
            conn=";"
        done
        local nfixed=$1
        IFS=";"
        explain_args $nfixed $arg_types
        IFS="_ "
        variadic=$2
        if [[ $variadic = v && $nfixed > 0 ]]; then
            printf ", ..."
        elif [ $variadic = v ]; then
            printf "..."
        fi
    fi
    printf ") returning "
    printf "%s" "$return_type"
}

function print_tagged {
    if [ -z "$*" ]; then
        return
    fi
    local currentTag="$*"
    local output="  $tag __$* {
"
    shift
    local idx=0
    while (( "$#" )); do
        eval "$explain_type"
        local field_type="$typ"
        print_tagged $tagName
        IFS="$OIFS"
        local output="$output    $("$(dirname "$0")/cdecl" declare _$idx as $field_type)
"
        IFS="_ "
        local idx=$(($idx+1))
    done
    local output="$output  };
"
    printf "%s" "$tags" | grep -s -- "^$currentTag\$" "-" > /dev/null
    if [ $? -eq 1 ]; then
        tags="$tags
$currentTag"
        printf "%s" "$output"
    fi
}

function print_tagged_types {
    tags=""
    eval "$explain_type"
    print_tagged $tagName
    while (( "$#" > 2 )); do
        eval "$explain_type"
        IFS="_ "
        print_tagged $tagName
    done
}

function write_trampoline {
    printf "static void __%s (void (*fptr)(), void *retval) {\n" "$*"
    explained_type=$(explain_fun_type "$@")
    print_tagged_types "$@"
    eval "$explain_type"
    local return_type="$typ"
    IFS="$OIFS"
    printf "  %s = %s;\n" "$("$(dirname "$0")/cdecl" -s declare fun as $explained_type)" "$("$(dirname "$0")/cdecl" -s cast fptr into $explained_type)"
    if [ "$return_type" != " void" ]; then
        printf "  %s = retval;\n" "$("$(dirname "$0")/cdecl" -s declare typed_retval as pointer to $return_type)"
    fi
    idx=0
    IFS="_ "
    while (( "$#" > 2 )); do
        eval "$explain_type"
        IFS="$OIFS"
        printf "  %s;\n" "$("$(dirname "$0")/cdecl" -s declare _$idx as $typ)"
        IFS="_ "
        printf "  __recv_message(&_$idx, sizeof(_$idx));\n"
        idx=$(($idx+1))
    done
    if [ "$return_type" != " void" ]; then
        printf "  *typed_retval = fun("
    else
        printf "  fun("
    fi
    conn=""
    IFS="$OIFS"
    for i in `seq 0 $(($idx-1))`; do
        printf "${conn}_$i"
        conn=", "
    done
    IFS="_ "
    printf ");\n"
    printf "}\n"
}

OIFS="$IFS"
IFS="_ "
while read line; do
    write_trampoline $line
done