1 | """Builtin_bracket.py."""
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2 | from __future__ import print_function
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3 |
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4 | from _devbuild.gen.id_kind_asdl import Id
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5 | from _devbuild.gen.syntax_asdl import loc, word, word_e, word_t, bool_expr
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6 | from _devbuild.gen.types_asdl import lex_mode_e
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7 | from _devbuild.gen.value_asdl import value
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8 |
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9 | from core import error
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10 | from core.error import e_usage, p_die
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11 | from core import vm
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12 | from frontend import match
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13 | from mycpp.mylib import log
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14 | from osh import bool_parse
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15 | from osh import sh_expr_eval
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16 | from osh import word_parse
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17 | from osh import word_eval
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18 |
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19 | _ = log
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20 |
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21 | from typing import cast, TYPE_CHECKING
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22 |
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23 | if TYPE_CHECKING:
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24 | from _devbuild.gen.runtime_asdl import cmd_value
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25 | from _devbuild.gen.syntax_asdl import bool_expr_t
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26 | from _devbuild.gen.types_asdl import lex_mode_t
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27 | from core.ui import ErrorFormatter
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28 | from core import optview
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29 | from core import state
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30 |
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31 |
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32 | class _StringWordEmitter(word_parse.WordEmitter):
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33 | """For test/[, we need a word parser that returns String.
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34 |
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35 | The BoolParser calls word_.BoolId(w), and deals with Kind.BoolUnary,
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36 | Kind.BoolBinary, etc. This is instead of Compound/Token (as in the
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37 | [[ case.
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38 | """
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39 |
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40 | def __init__(self, cmd_val):
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41 | # type: (cmd_value.Argv) -> None
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42 | self.cmd_val = cmd_val
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43 | self.i = 0
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44 | self.n = len(cmd_val.argv)
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45 |
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46 | def ReadWord(self, unused_lex_mode):
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47 | # type: (lex_mode_t) -> word.String
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48 | """Interface for bool_parse.py.
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49 |
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50 | TODO: This should probably be word_t
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51 | """
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52 | if self.i == self.n:
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53 | # Does it make sense to define Eof_Argv or something?
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54 | # TODO: Add a way to show this location.
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55 | w = word.String(Id.Eof_Real, '', None)
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56 | return w
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57 |
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58 | #log('ARGV %s i %d', self.argv, self.i)
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59 | s = self.cmd_val.argv[self.i]
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60 | arg_loc = self.cmd_val.arg_locs[self.i]
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61 |
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62 | self.i += 1
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63 |
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64 | # chained lookup; default is an operand word
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65 | id_ = match.BracketUnary(s)
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66 | if id_ == Id.Undefined_Tok:
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67 | id_ = match.BracketBinary(s)
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68 | if id_ == Id.Undefined_Tok:
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69 | id_ = match.BracketOther(s)
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70 | if id_ == Id.Undefined_Tok:
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71 | id_ = Id.Word_Compound
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72 |
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73 | return word.String(id_, s, arg_loc)
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74 |
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75 | def Read(self):
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76 | # type: () -> word.String
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77 | """Interface used for special cases below."""
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78 | return self.ReadWord(lex_mode_e.ShCommand)
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79 |
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80 | def Peek(self, offset):
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81 | # type: (int) -> str
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82 | """For special cases."""
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83 | return self.cmd_val.argv[self.i + offset]
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84 |
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85 | def Rewind(self, offset):
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86 | # type: (int) -> None
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87 | """For special cases."""
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88 | self.i -= offset
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89 |
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90 |
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91 | class _WordEvaluator(word_eval.StringWordEvaluator):
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92 |
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93 | def __init__(self):
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94 | # type: () -> None
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95 | word_eval.StringWordEvaluator.__init__(self)
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96 |
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97 | def EvalWordToString(self, w, eval_flags=0):
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98 | # type: (word_t, int) -> value.Str
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99 | # do_fnmatch: for the [[ == ]] semantics which we don't have!
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100 | # I think I need another type of node
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101 | # Maybe it should be BuiltinEqual and BuiltinDEqual? Parse it into a
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102 | # different tree.
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103 | assert w.tag() == word_e.String
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104 | string_word = cast(word.String, w)
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105 | return value.Str(string_word.s)
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106 |
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107 |
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108 | def _TwoArgs(w_parser):
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109 | # type: (_StringWordEmitter) -> bool_expr_t
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110 | """Returns an expression tree to be evaluated."""
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111 | w0 = w_parser.Read()
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112 | w1 = w_parser.Read()
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113 |
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114 | s0 = w0.s
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115 | if s0 == '!':
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116 | return bool_expr.LogicalNot(bool_expr.WordTest(w1))
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117 |
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118 | unary_id = Id.Undefined_Tok
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119 |
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120 | # YSH prefers long flags
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121 | if w0.s.startswith('--'):
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122 | if s0 == '--dir':
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123 | unary_id = Id.BoolUnary_d
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124 | elif s0 == '--exists':
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125 | unary_id = Id.BoolUnary_e
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126 | elif s0 == '--file':
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127 | unary_id = Id.BoolUnary_f
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128 | elif s0 == '--symlink':
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129 | unary_id = Id.BoolUnary_L
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130 |
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131 | if unary_id == Id.Undefined_Tok:
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132 | unary_id = match.BracketUnary(w0.s)
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133 |
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134 | if unary_id == Id.Undefined_Tok:
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135 | p_die('Expected unary operator, got %r (2 args)' % w0.s, loc.Word(w0))
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136 |
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137 | return bool_expr.Unary(unary_id, w1)
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138 |
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139 |
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140 | def _ThreeArgs(w_parser):
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141 | # type: (_StringWordEmitter) -> bool_expr_t
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142 | """Returns an expression tree to be evaluated."""
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143 | w0 = w_parser.Read()
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144 | w1 = w_parser.Read()
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145 | w2 = w_parser.Read()
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146 |
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147 | # NOTE: Order is important here.
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148 |
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149 | binary_id = match.BracketBinary(w1.s)
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150 | if binary_id != Id.Undefined_Tok:
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151 | return bool_expr.Binary(binary_id, w0, w2)
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152 |
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153 | if w1.s == '-a':
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154 | return bool_expr.LogicalAnd(bool_expr.WordTest(w0),
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155 | bool_expr.WordTest(w2))
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156 |
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157 | if w1.s == '-o':
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158 | return bool_expr.LogicalOr(bool_expr.WordTest(w0),
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159 | bool_expr.WordTest(w2))
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160 |
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161 | if w0.s == '!':
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162 | w_parser.Rewind(2)
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163 | child = _TwoArgs(w_parser)
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164 | return bool_expr.LogicalNot(child)
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165 |
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166 | if w0.s == '(' and w2.s == ')':
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167 | return bool_expr.WordTest(w1)
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168 |
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169 | p_die('Expected binary operator, got %r (3 args)' % w1.s, loc.Word(w1))
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170 |
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171 |
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172 | class Test(vm._Builtin):
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173 |
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174 | def __init__(self, need_right_bracket, exec_opts, mem, errfmt):
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175 | # type: (bool, optview.Exec, state.Mem, ErrorFormatter) -> None
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176 | self.need_right_bracket = need_right_bracket
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177 | self.exec_opts = exec_opts
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178 | self.mem = mem
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179 | self.errfmt = errfmt
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180 |
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181 | def Run(self, cmd_val):
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182 | # type: (cmd_value.Argv) -> int
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183 | """The test/[ builtin.
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184 |
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185 | The only difference between test and [ is that [ needs a
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186 | matching ].
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187 | """
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188 | if self.need_right_bracket: # Preprocess right bracket
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189 | if self.exec_opts.simple_test_builtin():
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190 | e_usage("should be invoked as 'test' (simple_test_builtin)",
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191 | loc.Missing)
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192 |
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193 | strs = cmd_val.argv
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194 | if len(strs) == 0 or strs[-1] != ']':
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195 | self.errfmt.Print_('missing closing ]',
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196 | blame_loc=cmd_val.arg_locs[0])
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197 | return 2
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198 | # Remove the right bracket
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199 | cmd_val.argv.pop()
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200 | cmd_val.arg_locs.pop()
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201 |
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202 | w_parser = _StringWordEmitter(cmd_val)
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203 | w_parser.Read() # dummy: advance past argv[0]
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204 | b_parser = bool_parse.BoolParser(w_parser)
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205 |
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206 | # There is a fundamental ambiguity due to poor language design, in cases like:
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207 | # [ -z ]
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208 | # [ -z -a ]
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209 | # [ -z -a ] ]
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210 | #
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211 | # See posixtest() in bash's test.c:
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212 | # "This is an implementation of a Posix.2 proposal by David Korn."
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213 | # It dispatches on expressions of length 0, 1, 2, 3, 4, and N args. We do
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214 | # the same here.
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215 | #
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216 | # Another ambiguity:
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217 | # -a is both a unary prefix operator and an infix operator. How to fix this
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218 | # ambiguity?
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219 |
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220 | bool_node = None # type: bool_expr_t
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221 | n = len(cmd_val.argv) - 1
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222 |
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223 | if self.exec_opts.simple_test_builtin() and n > 3:
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224 | e_usage(
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225 | "should only have 3 arguments or fewer (simple_test_builtin)",
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226 | loc.Missing)
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227 |
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228 | try:
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229 | if n == 0:
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230 | return 1 # [ ] is False
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231 | elif n == 1:
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232 | w = w_parser.Read()
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233 | bool_node = bool_expr.WordTest(w)
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234 | elif n == 2:
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235 | bool_node = _TwoArgs(w_parser)
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236 | elif n == 3:
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237 | bool_node = _ThreeArgs(w_parser)
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238 | if n == 4:
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239 | a0 = w_parser.Peek(0)
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240 | if a0 == '!':
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241 | w_parser.Read() # skip !
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242 | child = _ThreeArgs(w_parser)
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243 | bool_node = bool_expr.LogicalNot(child)
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244 | elif a0 == '(' and w_parser.Peek(3) == ')':
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245 | w_parser.Read() # skip ')'
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246 | bool_node = _TwoArgs(w_parser)
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247 | else:
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248 | pass # fallthrough
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249 |
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250 | if bool_node is None:
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251 | bool_node = b_parser.ParseForBuiltin()
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252 |
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253 | except error.Parse as e:
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254 | self.errfmt.PrettyPrintError(e, prefix='(test) ')
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255 | return 2
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256 |
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257 | word_ev = _WordEvaluator()
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258 |
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259 | # We technically don't need mem because we don't support BASH_REMATCH here.
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260 | # We want [ a -eq a ] to always be an error, unlike [[ a -eq a ]]. This is
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261 | # a weird case of [[ being less strict.
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262 | bool_ev = sh_expr_eval.BoolEvaluator(self.mem,
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263 | self.exec_opts,
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264 | None,
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265 | None,
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266 | self.errfmt,
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267 | always_strict=True)
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268 | bool_ev.word_ev = word_ev
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269 | bool_ev.CheckCircularDeps()
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270 | try:
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271 | b = bool_ev.EvalB(bool_node)
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272 | except error._ErrorWithLocation as e:
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273 | # We want to catch e_die() and e_strict(). Those are both FatalRuntime
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274 | # errors now, but it might not make sense later.
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275 |
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276 | # NOTE: This doesn't seem to happen. We have location info for all
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277 | # errors that arise out of [.
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278 | #if not e.HasLocation():
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279 | # raise
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280 |
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281 | self.errfmt.PrettyPrintError(e, prefix='(test) ')
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282 | return 2 # 1 means 'false', and this usage error is like a parse error.
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283 |
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284 | status = 0 if b else 1
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285 | return status
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