# Gdb pretty printer for zsh wordcode values.

# python execfile("wordcode.py")
# set print array on
# print *ecbuf@22
# note that you'll get garbage values for codes that reference strings

from operator import itemgetter

class WordcodePrinter:
    WC_END     = 0   
    WC_LIST    = 1
    WC_SUBLIST = 2
    WC_PIPE    = 3
    WC_REDIR   = 4
    WC_ASSIGN  = 5
    WC_SIMPLE  = 6
    WC_TYPESET = 7
    WC_SUBSH   = 8
    WC_CURSH   = 9
    WC_TIMED   = 10
    WC_FUNCDEF = 11
    WC_FOR     = 12
    WC_SELECT  = 13
    WC_WHILE   = 14
    WC_REPEAT  = 15
    WC_CASE    = 16
    WC_IF      = 17
    WC_COND    = 18
    WC_ARITH   = 19
    WC_AUTOFN  = 20
    WC_TRY     = 21

    WC_CODEBITS  = 5
    Z_END        = (1<<4) 
    Z_SIMPLE     = (1<<5)
    WC_LIST_FREE = (6)

    NAME = [ "End", "List", "SubList", "Pipe", "Redir", "Assign", "Simple",
             "Typeset", "Subsh", "Cursh", "Timed", "Funcdef", "For",
             "Select", "While", "Repeat", "Case", "If", "Cond", "Arith",
             "Autofn", "Try" ]
    
    def __init__(self, val):
        self.val = val

    def wc_code(self, code):
        return int(code) & ((1 << self.WC_CODEBITS) - 1)

    def wc_data(self, code):
        return int(code) >> self.WC_CODEBITS

    def wc_list_type(self, data):
        return '|'.join(map(itemgetter(1), filter(lambda (i,s): data & (1<<i),
            enumerate(["TIMED", "SYNC", "ASYNC", "DISOWN", "END", "SIMPLE"]))))

    def wc_sublist_type(self, data):
        return [ "END", "AND", "OR" ][data & 3]

    def wc_redir_type(self, data):
        return [">", ">|", ">>", ">>|", "&>", ">&|", ">>&", ">>&|", "<>",
            "<", "<<", "<<-", "<<<", "<&n", ">&n", ">&-, <&-", "< <(...)",
            "> >(...)" ][data & 0x1f]

    def wc_sublist_flags(self, data):
        return '|'.join(map(itemgetter(1), filter(lambda (i,s): data & (1<<i),
            enumerate(["COPROC", "NOT", "SIMPLE" ], start=2))))

    def wc_if_type(self, data):
        return [ "head", "if", "elif", "else" ][data & 3]

    def wc_for_type(self, data):
        return [ "pparam", "list", "cond" ][data & 3]

    def wc_case_type(self, data):
        return [ "head", "or", "and", "testand" ][data & 7]

    def wc_cond_type(self, data):
        return [ "!", "&&", "||", "=", "==", "!=", "<",
                 ">", "-nt", "-ot", "-ef", "-eq", "-ne", "-lt", "-gt", "-le",
                 "-ge", "=~", "MOD", "MOD(infix)" ][data & 127]

    def to_string(self):
        try:
            code = self.wc_code(self.val)
            data = self.wc_data(self.val)
            name = self.NAME[code]
            if (code == self.WC_LIST):
                name += '(type={}, skip={})'.format(self.wc_list_type(data), data >> 6)
            elif (code == self.WC_SUBLIST and data & 0x1c):
                name += '(type={}, flags={}, skip={})'.format(
                    self.wc_sublist_type(data), self.wc_sublist_flags(data), data >> 5)
            elif (code == self.WC_SUBLIST):
                name += '(type={}, skip={})'.format(self.wc_sublist_type(data),
                    data >> 5)
            elif (code == self.WC_REDIR):
              name += '(type={}{})'.format(self.wc_redir_type(data),
                  ", varid=true" if (data & 0x20) else "")
            elif (code == self.WC_ASSIGN):
              if data & 2: name += "+="
              name += "(array[{}])".format(data >> 2) if data & 1 else "(scalar)"
            elif (code == self.WC_SUBSH or code == self.WC_CURSH
                    or code == self.WC_REPEAT or code == self.WC_TRY
                    or code == self.WC_FUNCDEF):
                name += '(skip={})'.format(data)
            elif (code == self.WC_TIMED):
                name += '(type={})'.format("pipe" if data else "empty")
            elif (code == self.WC_PIPE):
                name += '(type={}, line={})'.format(
		    "mid" if (data & 1) else "end", (data >> 1))
            elif (code == self.WC_FOR):
                name += '(type={}, skip={})'.format(self.wc_for_type(data), data >> 2)
            elif (code == self.WC_SELECT):
                name += '(type={}, skip={})'.format(
		    "pparam" if (data & 1) else "list", (data >> 1))
            elif (code == self.WC_WHILE):
                if data & 1: name += '/until'
                name += '(skip={})'.format(data >> 1)
            elif (code == self.WC_CASE):
                name += '(type={}, skip={})'.format(self.wc_case_type(data), data >> 3)
            elif (code == self.WC_SIMPLE or code == self.WC_TYPESET):
                name += '(argc={})'.format(data)
            elif (code == self.WC_IF):
                name += '(type={}, skip={})'.format(self.wc_if_type(data), data >> 2)
            elif (code == self.WC_COND):
                name += '({}, skip={})'.format(self.wc_cond_type(data), data >> 7)
        except IndexError:
            name = int(code) # any error likely means it isn't a wordcode

        return name

def zsh(val):
    if str(val.type) == 'wordcode':
        return WordcodePrinter(val)
    return None

gdb.pretty_printers.append(zsh)