"""
Copyright (C) 2018-2019 Oracle Corporation

This file is part of VirtualBox Open Source Edition (OSE), as
available from http://www.virtualbox.org. This file is free software;
you can redistribute it and/or modify it under the terms of the GNU
General Public License (GPL) as published by the Free Software
Foundation, in version 2 as it comes in the "COPYING" file of the
VirtualBox OSE distribution. VirtualBox OSE is distributed in the
hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
"""

import sys

def GenerateForwarders():

    # Get list of functions.
    exports_file = open(sys.argv[1], "r")
    if not exports_file:
        print("Error: couldn't open %s file!" % filename)
        sys.exit()

    names = []
    cbArgs = []
    for line in exports_file.readlines():
        line = line.strip()
        if len(line) > 0 and line[0] != ';' and line != 'EXPORTS':
            # Parse 'glAccum = glAccum@8'
            words = line.split('=', 1)

            # Function name
            names.append(words[0].strip())

            # Size of arguments in bytes
            words = words[1].split('@')
            cbArgs.append(words[1].strip())

    exports_file.close()


    #
    # Assembler forwarders
    #
    asm_file = open(sys.argv[2], "w")
    if not asm_file:
        print("Error: couldn't open %s file!" % filename)
        sys.exit()

    asm_file.write('%include "iprt/asmdefs.mac"\n')
    asm_file.write('\n')
    asm_file.write(';;;; Enable ICD_LAZY_LOAD to lazy load the ICD DLL (does not work on Win64)\n')
    asm_file.write('; %define ICD_LAZY_LOAD 1\n')
    asm_file.write('\n')
    asm_file.write('%ifdef RT_ARCH_AMD64\n')
    asm_file.write('%define PTR_SIZE_PREFIX qword\n')
    asm_file.write('%else ; X86\n')
    asm_file.write('%define PTR_SIZE_PREFIX dword\n')
    asm_file.write('%endif\n')
    asm_file.write('\n')
    asm_file.write('%ifdef ICD_LAZY_LOAD\n')
    asm_file.write('extern NAME(VBoxLoadICD)\n')
    asm_file.write('%endif\n')
    asm_file.write('extern NAME(g_hmodICD)\n')

    for index in range(len(names)):
        fn = names[index]
        cbRet = cbArgs[index]
        asm_file.write('\n')
        asm_file.write('BEGINPROC_EXPORTED %s\n' % fn)
        asm_file.write('    extern NAME(pfn_%s)\n' % fn)
        asm_file.write(';    int3\n')
        asm_file.write('%ifdef ICD_LAZY_LOAD\n')
        asm_file.write('    mov   xAX, PTR_SIZE_PREFIX NAME(g_hmodICD)\n')
        asm_file.write('    mov   xAX, [xAX]\n')
        asm_file.write('    or    xAX, xAX\n')
        asm_file.write('    jnz   l_icd_loaded_%s\n' % fn)
        asm_file.write('    call  NAME(VBoxLoadICD)\n')
        asm_file.write('l_icd_loaded_%s:\n' % fn)
        asm_file.write('%endif\n')
        asm_file.write('    mov   xAX, PTR_SIZE_PREFIX NAME(pfn_%s)\n' % fn)
        asm_file.write('    mov   xAX, [xAX]\n')
        asm_file.write('    or    xAX, xAX\n')
        asm_file.write('    jnz   l_jmp_to_%s\n' % fn)
        asm_file.write('%ifdef RT_ARCH_AMD64\n')
        asm_file.write('    ret\n')
        asm_file.write('%else ; X86\n')
        asm_file.write('    ret %s\n' % cbRet)
        asm_file.write('%endif\n')
        asm_file.write('l_jmp_to_%s:\n' % fn)
        asm_file.write('    jmp   xAX\n')
        asm_file.write('ENDPROC %s\n' % fn)

    asm_file.close()

GenerateForwarders()
