#!/bin/sh

# Translates DEC64's Windows-compatible MASM on stdin to
# UNIX-compatible NASM on stdout. Not general purpose.

#   0. Use the UNIX calling convention.
#   1. Replace equ with %define.
#   2. Replace public with global.
#   3. Replace unary macro with %macro.
#   4. Replace nullary macro with %macro.
#   5. Replace endm with %endmacro.
#   6. Replace if with %if.
#   7. Replace endif with %endif.
#   8. Replace named with positional parameter.
#   9. Replace segment with section.
#  10. Replace qword with dq.
#  11. Remove execute segment.
#  12. Flatten nested index: [a][b] -> [a+b].
#  13. Remove extraneous suffix matter.
#  14. Remove extraneous suffix matter.
#  15. Remove title.

sed \
    -E \
    -e "s/^UNIX    equ 0/%define UNIX 1/g" \
    -e "s/^(\w+)\s+equ\s+(.+)/%define \1 \2/g" \
    -e "s/^public /global /g" \
    -e "s/^(\w+) macro function/%macro \1 1/g" \
    -e "s/^(\w+) macro/%macro \1 0/g" \
    -e "s/^    endm/    %endmacro/g" \
    -e "s/^    if /    %if /g" \
    -e "s/^    endif/    %endif/g" \
    -e "s/^    (call|jmp)\s+function/    \1 %1/g" \
    -e "s/^dec64_data segment para read/dec64_code section .text/g" \
    -e "/^dec64_data ends/d" \
    -e "s/^    qword/    dq   /g" \
    -e "/^dec64_code segment para execute/d" \
    -e "s/(ptr )?\[(.+?)\]\[(.+?)\]/[\2+\3]/g" \
    -e "/^dec64_code ends/d" \
    -e "/^    end\b/d" \
    -e "/^title /d"