1 | #!/usr/bin/env python
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2 | # Copyright 2016 Andy Chu. All rights reserved.
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3 | # Licensed under the Apache License, Version 2.0 (the "License");
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4 | # you may not use this file except in compliance with the License.
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5 | # You may obtain a copy of the License at
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6 | #
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7 | # http://www.apache.org/licenses/LICENSE-2.0
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8 | from __future__ import print_function
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9 | """
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10 | cmd_parse.py - Parse high level shell commands.
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11 | """
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12 |
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13 | from asdl import const
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14 |
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15 | from core import braces
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16 | from core import word
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17 | from core import util
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18 |
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19 | from osh.meta import ast, Id, Kind, types
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20 | from osh.lex import VAR_NAME_RE
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21 | from osh.bool_parse import BoolParser
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22 |
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23 | log = util.log
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24 | command_e = ast.command_e
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25 | word_e = ast.word_e
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26 | assign_op_e = ast.assign_op_e
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27 | lex_mode_e = types.lex_mode_e
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28 |
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29 |
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30 | class CommandParser(object):
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31 | """
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32 | Args:
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33 | word_parse: to get a stream of words
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34 | lexer: for lookahead in function def, PushHint of ()
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35 | line_reader: for here doc
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36 | """
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37 | def __init__(self, w_parser, lexer, line_reader, arena):
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38 | self.w_parser = w_parser # for normal parsing
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39 | self.lexer = lexer # for fast lookahead to (, for function defs
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40 | self.line_reader = line_reader # for here docs
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41 | self.arena = arena
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42 |
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43 | self.Reset()
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44 |
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45 | def Reset(self):
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46 | self.error_stack = []
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47 | self.completion_stack = []
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48 |
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49 | # Cursor state set by _Peek()
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50 | self.next_lex_mode = lex_mode_e.OUTER
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51 | self.cur_word = None # current word
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52 | self.c_kind = Kind.Undefined
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53 | self.c_id = Id.Undefined_Tok
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54 |
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55 | self.pending_here_docs = []
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56 |
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57 | def Error(self):
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58 | return self.error_stack
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59 |
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60 | def _BadWord(self, msg, w):
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61 | """Helper function for errors involving a word.
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62 |
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63 | Args:
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64 | msg: format string with a single %s token
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65 | w: Word
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66 | """
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67 | self.AddErrorContext(msg, w, word=w)
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68 |
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69 | def AddErrorContext(self, msg, *args, **kwargs):
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70 | err = util.ParseError(msg, *args, **kwargs)
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71 | self.error_stack.append(err)
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72 |
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73 | def GetCompletionState(self):
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74 | return self.completion_stack
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75 |
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76 | def _MaybeReadHereDocs(self):
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77 | for h in self.pending_here_docs:
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78 | lines = []
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79 | #log('HERE %r' % h.here_end)
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80 | while True:
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81 | # If op is <<-, strip off all leading tabs (NOT spaces).
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82 | # (in C++, just bump the start?)
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83 | line_id, line = self.line_reader.GetLine()
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84 |
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85 | #print("LINE %r %r" % (line, h.here_end))
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86 | if not line: # EOF
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87 | # An unterminated here doc is just a warning in bash. We make it
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88 | # fatal because we want to be strict, and because it causes problems
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89 | # reporting other errors.
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90 | # Attribute it to the << in <<EOF for now.
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91 | self.AddErrorContext('Unterminated here doc', span_id=h.spids[0])
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92 | return False
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93 |
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94 | # NOTE: Could do this runtime to preserve LST.
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95 | if h.op_id == Id.Redir_DLessDash:
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96 | line = line.lstrip('\t')
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97 | if line.rstrip() == h.here_end:
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98 | break
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99 |
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100 | lines.append((line_id, line))
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101 |
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102 | parts = []
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103 | if h.do_expansion:
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104 | # NOTE: We read all lines at once, instead of doing it line-by-line,
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105 | # because of cases like this:
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106 | # cat <<EOF
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107 | # 1 $(echo 2
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108 | # echo 3) 4
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109 | # EOF
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110 |
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111 | from osh import parse_lib # Avoid circular import
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112 | w_parser = parse_lib.MakeWordParserForHereDoc(lines, self.arena)
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113 | word = w_parser.ReadHereDocBody()
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114 | if not word:
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115 | self.AddErrorContext(
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116 | 'Error reading here doc body: %s', w_parser.Error())
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117 | return False
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118 | h.body = word
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119 | h.was_filled = True
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120 | else:
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121 | # Each line is a single span. TODO: Add span_id to token.
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122 | tokens = [
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123 | ast.token(Id.Lit_Chars, line, const.NO_INTEGER)
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124 | for _, line in lines]
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125 | parts = [ast.LiteralPart(t) for t in tokens]
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126 | h.body = ast.CompoundWord(parts)
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127 | h.was_filled = True
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128 |
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129 | # No .clear() until Python 3.3.
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130 | del self.pending_here_docs[:]
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131 |
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132 | return True
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133 |
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134 | def _Next(self, lex_mode=lex_mode_e.OUTER):
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135 | """Helper method."""
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136 | self.next_lex_mode = lex_mode
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137 |
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138 | def Peek(self):
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139 | """Public method for REPL."""
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140 | if not self._Peek():
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141 | return None
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142 | return self.cur_word
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143 |
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144 | def _Peek(self):
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145 | """Helper method.
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146 |
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147 | Returns True for success and False on error. Error examples: bad command
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148 | sub word, or unterminated quoted string, etc.
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149 | """
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150 | if self.next_lex_mode != lex_mode_e.NONE:
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151 | w = self.w_parser.ReadWord(self.next_lex_mode)
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152 | if w is None:
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153 | error_stack = self.w_parser.Error()
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154 | self.error_stack.extend(error_stack)
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155 | return False
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156 |
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157 | # Here docs only happen in command mode, so other kinds of newlines don't
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158 | # count.
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159 | if w.tag == word_e.TokenWord and w.token.id == Id.Op_Newline:
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160 | if not self._MaybeReadHereDocs():
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161 | return False
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162 |
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163 | self.cur_word = w
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164 |
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165 | self.c_kind = word.CommandKind(self.cur_word)
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166 | self.c_id = word.CommandId(self.cur_word)
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167 | self.next_lex_mode = lex_mode_e.NONE
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168 | #print('_Peek', self.cur_word)
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169 | return True
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170 |
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171 | def _Eat(self, c_id):
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172 | """Consume a word of a type. If it doesn't match, return False.
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173 |
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174 | Args:
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175 | c_id: either EKeyword.* or a token type like Id.Right_Subshell.
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176 | TODO: Rationalize / type check this.
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177 | """
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178 | if not self._Peek():
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179 | return False
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180 | # TODO: It would be nicer to print the word type, right now we get a number
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181 | if self.c_id != c_id:
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182 | self.AddErrorContext(
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183 | "Expected word type %s, got %s", c_id, self.cur_word,
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184 | word=self.cur_word)
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185 | return False
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186 | self._Next()
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187 | return True
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188 |
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189 | def _NewlineOk(self):
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190 | """Check for optional newline and consume it."""
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191 | if not self._Peek():
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192 | return False
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193 | if self.c_id == Id.Op_Newline:
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194 | self._Next()
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195 | if not self._Peek():
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196 | return False
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197 | return True
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198 |
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199 | def ParseRedirect(self):
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200 | """
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201 | Problem: You don't know which kind of redir_node to instantiate before
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202 | this? You could stuff them all in one node, and then have a switch() on
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203 | the type.
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204 |
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205 | You need different types.
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206 | """
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207 | if not self._Peek(): return None
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208 | assert self.c_kind == Kind.Redir, self.cur_word
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209 |
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210 | left_spid = self.cur_word.token.span_id
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211 |
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212 | # For now only supporting single digit descriptor
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213 | first_char = self.cur_word.token.val[0]
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214 | if first_char.isdigit():
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215 | fd = int(first_char)
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216 | else:
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217 | fd = const.NO_INTEGER
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218 |
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219 | if self.c_id in (Id.Redir_DLess, Id.Redir_DLessDash): # here doc
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220 | node = ast.HereDoc()
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221 | node.op_id = self.c_id
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222 | node.body = None # not read yet
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223 | node.fd = fd
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224 | node.was_filled = False
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225 | node.spids.append(left_spid)
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226 | self._Next()
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227 |
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228 | if not self._Peek(): return None
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229 | # "If any character in word is quoted, the delimiter shall be formed by
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230 | # performing quote removal on word, and the here-document lines shall not
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231 | # be expanded. Otherwise, the delimiter shall be the word itself."
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232 | # NOTE: \EOF counts, or even E\OF
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233 | ok, node.here_end, quoted = word.StaticEval(self.cur_word)
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234 | if not ok:
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235 | self._BadWord('Error evaluating here doc delimiter: %s', self.cur_word)
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236 | return None
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237 | node.do_expansion = not quoted
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238 | self._Next()
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239 |
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240 | self.pending_here_docs.append(node) # will be filled on next newline.
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241 |
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242 | else:
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243 | node = ast.Redir()
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244 | node.op_id = self.c_id
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245 | node.fd = fd
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246 | node.spids.append(left_spid)
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247 | self._Next()
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248 |
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249 | if not self._Peek(): return None
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250 | if self.c_kind != Kind.Word:
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251 | self.AddErrorContext(
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252 | 'Expected word after redirect operator', word=self.cur_word)
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253 | return None
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254 |
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255 | new_word = word.TildeDetect(self.cur_word)
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256 | node.arg_word = new_word or self.cur_word
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257 | self._Next()
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258 |
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259 | return node
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260 |
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261 | def _ParseRedirectList(self):
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262 | """Try parsing any redirects at the cursor.
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263 |
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264 | This is used for blocks only, not commands.
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265 |
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266 | Return None on error.
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267 | """
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268 | redirects = []
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269 | while True:
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270 | if not self._Peek(): return None
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271 |
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272 | # This prediction needs to ONLY accept redirect operators. Should we
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273 | # make them a separate TokeNkind?
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274 | if self.c_kind != Kind.Redir:
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275 | break
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276 |
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277 | node = self.ParseRedirect()
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278 | if not node:
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279 | return None
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280 | redirects.append(node)
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281 | self._Next()
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282 | return redirects
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283 |
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284 | def _ScanSimpleCommand(self):
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285 | """First pass: Split into redirects and words."""
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286 | redirects = []
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287 | words = []
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288 | while True:
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289 | if not self._Peek(): return None
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290 | if self.c_kind == Kind.Redir:
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291 | node = self.ParseRedirect()
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292 | if not node: return None # e.g. EOF
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293 | redirects.append(node)
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294 |
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295 | elif self.c_kind == Kind.Word:
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296 | words.append(self.cur_word)
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297 |
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298 | else:
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299 | break
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300 | self._Next()
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301 | return redirects, words
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302 |
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303 | def _SplitSimpleCommandPrefix(self, words):
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304 | """
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305 | Second pass of SimpleCommand parsing: look for assignment words.
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306 | """
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307 | prefix_bindings = []
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308 | suffix_words = []
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309 |
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310 | done_prefix = False
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311 | for w in words:
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312 | if done_prefix:
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313 | suffix_words.append(w)
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314 | continue
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315 |
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316 | left_spid = word.LeftMostSpanForWord(w)
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317 |
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318 | kov = word.LooksLikeAssignment(w)
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319 | if kov:
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320 | k, op, v = kov
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321 | t = word.TildeDetect(v)
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322 | if t:
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323 | # t is an unevaluated word with TildeSubPart
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324 | prefix_bindings.append((k, op, t, left_spid))
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325 | else:
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326 | prefix_bindings.append((k, op, v, left_spid)) # v is unevaluated word
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327 | else:
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328 | done_prefix = True
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329 | suffix_words.append(w)
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330 |
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331 | return prefix_bindings, suffix_words
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332 |
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333 | def _MakeSimpleCommand(self, prefix_bindings, suffix_words, redirects):
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334 | # FOO=(1 2 3) ls is not allowed
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335 | for k, _, v, _ in prefix_bindings:
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336 | if word.HasArrayPart(v):
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337 | self.AddErrorContext(
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338 | 'Unexpected array literal in binding: %s', v, word=v)
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339 | return None
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340 |
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341 | # echo FOO=(1 2 3) is not allowed
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342 | # NOTE: Other checks can be inserted here. Can resolve builtins,
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343 | # functions, aliases, static PATH, etc.
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344 | for w in suffix_words:
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345 | kov = word.LooksLikeAssignment(w)
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346 | if kov:
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347 | _, _, v = kov
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348 | if word.HasArrayPart(v):
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349 | self.AddErrorContext('Unexpected array literal: %s', v, word=w)
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350 | return None
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351 |
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352 | # NOTE: # In bash, {~bob,~jane}/src works, even though ~ isn't the leading
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353 | # character of the initial word.
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354 | # However, this means we must do tilde detection AFTER brace EXPANSION, not
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355 | # just after brace DETECTION like we're doing here.
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356 | # The BracedWordTree instances have to be expanded into CompoundWord
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357 | # instances for the tilde detection to work.
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358 | words2 = braces.BraceDetectAll(suffix_words)
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359 | words3 = word.TildeDetectAll(words2)
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360 |
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361 | node = ast.SimpleCommand()
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362 | node.words = words3
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363 | node.redirects = redirects
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364 | for name, op, val, left_spid in prefix_bindings:
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365 | if op != assign_op_e.Equal:
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366 | # NOTE: Using spid of RHS for now, since we don't have one for op.
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367 | self.AddErrorContext('Expected = in environment binding, got +=',
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368 | word=val)
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369 | return None
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370 | pair = ast.env_pair(name, val)
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371 | pair.spids.append(left_spid)
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372 | node.more_env.append(pair)
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373 | return node
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374 |
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375 | def _MakeAssignment(self, assign_kw, suffix_words):
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376 | # First parse flags, e.g. -r -x -a -A. None of the flags have arguments.
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377 | flags = []
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378 | n = len(suffix_words)
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379 | i = 1
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380 | while i < n:
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381 | w = suffix_words[i]
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382 | ok, static_val, quoted = word.StaticEval(w)
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383 | if not ok or quoted:
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384 | break # can't statically evaluate
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385 |
|
386 | if static_val.startswith('-'):
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387 | flags.append(static_val)
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388 | else:
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389 | break # not a flag, rest are args
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390 | i += 1
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391 |
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392 | # Now parse bindings or variable names
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393 | assignments = []
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394 | while i < n:
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395 | w = suffix_words[i]
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396 | left_spid = word.LeftMostSpanForWord(w)
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397 | kov = word.LooksLikeAssignment(w)
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398 | if kov:
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399 | k, op, v = kov
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400 | t = word.TildeDetect(v)
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401 | if t:
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402 | # t is an unevaluated word with TildeSubPart
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403 | a = (k, op, t, left_spid)
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404 | else:
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405 | a = (k, op, v, left_spid) # v is unevaluated word
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406 | else:
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407 | # In aboriginal in variables/sources: export_if_blank does export "$1".
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408 | # We should allow that.
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409 |
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410 | # Parse this differently then?
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411 | # dynamic-export?
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412 | # It sets global variables.
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413 | ok, static_val, quoted = word.StaticEval(w)
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414 | if not ok or quoted:
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415 | self.AddErrorContext(
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416 | 'Variable names must be constant strings, got %s', w, word=w)
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417 | return None
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418 |
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419 | # No value is equivalent to ''
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420 | m = VAR_NAME_RE.match(static_val)
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421 | if not m:
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422 | self.AddErrorContext('Invalid variable name %r', static_val, word=w)
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423 | return None
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424 | a = (static_val, assign_op_e.Equal, None, left_spid)
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425 |
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426 | assignments.append(a)
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427 | i += 1
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428 |
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429 | # TODO: Also make with LhsIndexedName
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430 | pairs = []
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431 | for lhs, op, rhs, spid in assignments:
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432 | p = ast.assign_pair(ast.LhsName(lhs), op, rhs)
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433 | p.spids.append(spid)
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434 | pairs.append(p)
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435 |
|
436 | node = ast.Assignment(assign_kw, flags, pairs)
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437 |
|
438 | return node
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439 |
|
440 | # Flags that indicate an assignment should be parsed like a command.
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441 | _ASSIGN_COMMANDS = set([
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442 | (Id.Assign_Declare, '-f'), # function defs
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443 | (Id.Assign_Declare, '-F'), # function names
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444 | (Id.Assign_Declare, '-p'), # print
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445 |
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446 | (Id.Assign_Typeset, '-f'),
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447 | (Id.Assign_Typeset, '-F'),
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448 | (Id.Assign_Typeset, '-p'),
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449 |
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450 | (Id.Assign_Local, '-p'),
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451 | (Id.Assign_Readonly, '-p'),
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452 | # Hm 'export -p' is more like a command. But we're parsing it
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453 | # dynamically now because of some wrappers.
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454 | # Maybe we could change this.
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455 | #(Id.Assign_Export, '-p'),
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456 | ])
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457 | # Flags to parse like assignments: -a -r -x (and maybe -i)
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458 |
|
459 | def ParseSimpleCommand(self):
|
460 | """
|
461 | Fixed transcription of the POSIX grammar (TODO: port to grammar/Shell.g)
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462 |
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463 | io_file : '<' filename
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464 | | LESSAND filename
|
465 | ...
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466 |
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467 | io_here : DLESS here_end
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468 | | DLESSDASH here_end
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469 |
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470 | redirect : IO_NUMBER (io_redirect | io_here)
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471 |
|
472 | prefix_part : ASSIGNMENT_WORD | redirect
|
473 | cmd_part : WORD | redirect
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474 |
|
475 | assign_kw : Declare | Export | Local | Readonly
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476 |
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477 | # Without any words it is parsed as a command, not an assignment
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478 | assign_listing : assign_kw
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479 |
|
480 | # Now we have something to do (might be changing assignment flags too)
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481 | # NOTE: any prefixes should be a warning, but they are allowed in shell.
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482 | assignment : prefix_part* assign_kw (WORD | ASSIGNMENT_WORD)+
|
483 |
|
484 | # an external command, a function call, or a builtin -- a "word_command"
|
485 | word_command : prefix_part* cmd_part+
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486 |
|
487 | simple_command : assign_listing
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488 | | assignment
|
489 | | proc_command
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490 |
|
491 | Simple imperative algorithm:
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492 |
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493 | 1) Read a list of words and redirects. Append them to separate lists.
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494 | 2) Look for the first non-assignment word. If it's declare, etc., then
|
495 | keep parsing words AND assign words. Otherwise, just parse words.
|
496 | 3) If there are no non-assignment words, then it's a global assignment.
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497 |
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498 | { redirects, global assignments } OR
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499 | { redirects, prefix_bindings, words } OR
|
500 | { redirects, ERROR_prefix_bindings, keyword, assignments, words }
|
501 |
|
502 | THEN CHECK that prefix bindings don't have any array literal parts!
|
503 | global assignment and keyword assignments can have the of course.
|
504 | well actually EXPORT shouldn't have them either -- WARNING
|
505 |
|
506 | 3 cases we want to warn: prefix_bindings for assignment, and array literal
|
507 | in prefix bindings, or export
|
508 |
|
509 | A command can be an assignment word, word, or redirect on its own.
|
510 |
|
511 | ls
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512 | >out.txt
|
513 |
|
514 | >out.txt FOO=bar # this touches the file
|
515 |
|
516 | Or any sequence:
|
517 | ls foo bar
|
518 | <in.txt ls foo bar >out.txt
|
519 | <in.txt ls >out.txt foo bar
|
520 |
|
521 | Or add one or more environment bindings:
|
522 | VAR=val env
|
523 | >out.txt VAR=val env
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524 |
|
525 | here_end vs filename is a matter of whether we test that it's quoted. e.g.
|
526 | <<EOF vs <<'EOF'.
|
527 | """
|
528 | result = self._ScanSimpleCommand()
|
529 | if not result: return None
|
530 | redirects, words = result
|
531 |
|
532 | if not words: # e.g. >out.txt # redirect without words
|
533 | node = ast.SimpleCommand()
|
534 | node.redirects = redirects
|
535 | return node
|
536 |
|
537 | prefix_bindings, suffix_words = self._SplitSimpleCommandPrefix(words)
|
538 |
|
539 | if not suffix_words: # ONE=1 TWO=2 (with no other words)
|
540 | if redirects:
|
541 | binding1 = prefix_bindings[0]
|
542 | _, _, _, spid = binding1
|
543 | self.AddErrorContext('Got redirects in global assignment',
|
544 | span_id=spid)
|
545 | return None
|
546 |
|
547 | pairs = []
|
548 | for lhs, op, rhs, spid in prefix_bindings:
|
549 | p = ast.assign_pair(ast.LhsName(lhs), op, rhs)
|
550 | p.spids.append(spid)
|
551 | pairs.append(p)
|
552 |
|
553 | node = ast.Assignment(Id.Assign_None, [], pairs)
|
554 | left_spid = word.LeftMostSpanForWord(words[0])
|
555 | node.spids.append(left_spid) # no keyword spid to skip past
|
556 | return node
|
557 |
|
558 | kind, kw_token = word.KeywordToken(suffix_words[0])
|
559 |
|
560 | if kind == Kind.Assign:
|
561 | # Here we StaticEval suffix_words[1] to see if it's a command like
|
562 | # 'typeset -p'. Then it becomes a SimpleCommand node instead of an
|
563 | # Assignment. Note we're not handling duplicate flags like 'typeset
|
564 | # -pf'. I see this in bashdb (bash debugger) but it can just be changed
|
565 | # to 'typeset -p -f'.
|
566 | is_command = False
|
567 | if len(suffix_words) > 1:
|
568 | ok, val, _ = word.StaticEval(suffix_words[1])
|
569 | if ok and (kw_token.id, val) in self._ASSIGN_COMMANDS:
|
570 | is_command = True
|
571 |
|
572 | if is_command: # declare -f, declare -p, typeset -p, etc.
|
573 | node = self._MakeSimpleCommand(prefix_bindings, suffix_words,
|
574 | redirects)
|
575 | return node
|
576 |
|
577 | else: # declare str='', declare -a array=()
|
578 | if redirects:
|
579 | # Attach the error location to the keyword. It would be more precise
|
580 | # to attach it to the
|
581 | self.AddErrorContext('Got redirects in assignment', token=kw_token)
|
582 | return None
|
583 |
|
584 | if prefix_bindings: # FOO=bar local spam=eggs not allowed
|
585 | # Use the location of the first value. TODO: Use the whole word
|
586 | # before splitting.
|
587 | _, _, v0, _ = prefix_bindings[0]
|
588 | self.AddErrorContext(
|
589 | 'Invalid prefix bindings in assignment: %s', prefix_bindings,
|
590 | word=v0)
|
591 | return None
|
592 |
|
593 | node = self._MakeAssignment(kw_token.id, suffix_words)
|
594 | if not node: return None
|
595 | node.spids.append(kw_token.span_id)
|
596 | return node
|
597 |
|
598 | elif kind == Kind.ControlFlow:
|
599 | if redirects:
|
600 | self.AddErrorContext('Got redirects in control flow: %s', redirects)
|
601 | return None
|
602 |
|
603 | if prefix_bindings: # FOO=bar local spam=eggs not allowed
|
604 | # Use the location of the first value. TODO: Use the whole word before
|
605 | # splitting.
|
606 | _, _, v0, _ = prefix_bindings[0]
|
607 | self.AddErrorContext(
|
608 | 'Invalid prefix bindings in control flow: %s', prefix_bindings,
|
609 | word=v0)
|
610 | return None
|
611 |
|
612 | # Attach the token for errors. (Assignment may not need it.)
|
613 | if len(suffix_words) == 1:
|
614 | arg_word = None
|
615 | elif len(suffix_words) == 2:
|
616 | arg_word = suffix_words[1]
|
617 | else:
|
618 | # Underline the extra word.
|
619 | self.AddErrorContext(
|
620 | 'Unexpected argument to %r', kw_token.val, word=suffix_words[2])
|
621 | return None
|
622 |
|
623 | return ast.ControlFlow(kw_token, arg_word)
|
624 |
|
625 | else:
|
626 | node = self._MakeSimpleCommand(prefix_bindings, suffix_words, redirects)
|
627 | return node
|
628 |
|
629 | def ParseBraceGroup(self):
|
630 | """
|
631 | brace_group : LBrace command_list RBrace ;
|
632 | """
|
633 | left_spid = word.LeftMostSpanForWord(self.cur_word)
|
634 | if not self._Eat(Id.Lit_LBrace): return None
|
635 |
|
636 | c_list = self.ParseCommandList()
|
637 | if not c_list: return None
|
638 |
|
639 | # Not needed
|
640 | #right_spid = word.LeftMostSpanForWord(self.cur_word)
|
641 | if not self._Eat(Id.Lit_RBrace): return None
|
642 |
|
643 | node = ast.BraceGroup(c_list.children)
|
644 | node.spids.append(left_spid)
|
645 | return node
|
646 |
|
647 | def ParseDoGroup(self):
|
648 | """
|
649 | Used by ForEach, ForExpr, While, Until. Should this be a Do node?
|
650 |
|
651 | do_group : Do command_list Done ; /* Apply rule 6 */
|
652 | """
|
653 | if not self._Eat(Id.KW_Do): return None
|
654 | do_spid = word.LeftMostSpanForWord(self.cur_word) # after _Eat
|
655 |
|
656 | c_list = self.ParseCommandList() # could be any thing
|
657 | if not c_list: return None
|
658 |
|
659 | if not self._Eat(Id.KW_Done): return None
|
660 | done_spid = word.LeftMostSpanForWord(self.cur_word) # after _Eat
|
661 |
|
662 | node = ast.DoGroup(c_list.children)
|
663 | node.spids.extend((do_spid, done_spid))
|
664 | return node
|
665 |
|
666 | def ParseForWords(self):
|
667 | """
|
668 | for_words : WORD* for_sep
|
669 | ;
|
670 | for_sep : ';' newline_ok
|
671 | | NEWLINES
|
672 | ;
|
673 | """
|
674 | words = []
|
675 | # The span_id of any semi-colon, so we can remove it.
|
676 | semi_spid = const.NO_INTEGER
|
677 |
|
678 | while True:
|
679 | if not self._Peek(): return None
|
680 | if self.c_id == Id.Op_Semi:
|
681 | semi_spid = self.cur_word.token.span_id # TokenWord
|
682 | self._Next()
|
683 | if not self._NewlineOk(): return None
|
684 | break
|
685 | elif self.c_id == Id.Op_Newline:
|
686 | self._Next()
|
687 | break
|
688 | if self.cur_word.tag != word_e.CompoundWord:
|
689 | # TODO: Can we also show a pointer to the 'for' keyword?
|
690 | self.AddErrorContext('Invalid word in for loop', word=self.cur_word)
|
691 | return None
|
692 |
|
693 | words.append(self.cur_word)
|
694 | self._Next()
|
695 | return words, semi_spid
|
696 |
|
697 | def _ParseForExprLoop(self):
|
698 | """
|
699 | for (( init; cond; update )) for_sep? do_group
|
700 | """
|
701 | node = self.w_parser.ReadForExpression()
|
702 | if not node:
|
703 | error_stack = self.w_parser.Error()
|
704 | self.error_stack.extend(error_stack)
|
705 | self.AddErrorContext("Parsing for expression failed")
|
706 | return None
|
707 | self._Next()
|
708 |
|
709 | if not self._Peek(): return None
|
710 | if self.c_id == Id.Op_Semi:
|
711 | self._Next()
|
712 | if not self._NewlineOk(): return None
|
713 | elif self.c_id == Id.Op_Newline:
|
714 | self._Next()
|
715 | elif self.c_id == Id.KW_Do: # missing semicolon/newline allowed
|
716 | pass
|
717 | else:
|
718 | self.AddErrorContext(
|
719 | 'Unexpected token after for expression: %s', self.cur_word,
|
720 | word=self.cur_word)
|
721 | return None
|
722 |
|
723 | body_node = self.ParseDoGroup()
|
724 | if not body_node: return None
|
725 |
|
726 | node.body = body_node
|
727 | return node
|
728 |
|
729 | def _ParseForEachLoop(self):
|
730 | node = ast.ForEach()
|
731 | node.do_arg_iter = False
|
732 |
|
733 | ok, iter_name, quoted = word.StaticEval(self.cur_word)
|
734 | if not ok or quoted:
|
735 | self.AddErrorContext(
|
736 | "Invalid for loop variable", word=self.cur_word)
|
737 | return None
|
738 | if not VAR_NAME_RE.match(iter_name):
|
739 | self.AddErrorContext(
|
740 | "Invalid for loop variable name", word=self.cur_word)
|
741 | return None
|
742 | node.iter_name = iter_name
|
743 | self._Next() # skip past name
|
744 |
|
745 | if not self._NewlineOk(): return None
|
746 |
|
747 | in_spid = const.NO_INTEGER
|
748 | semi_spid = const.NO_INTEGER
|
749 |
|
750 | if not self._Peek(): return None
|
751 | if self.c_id == Id.KW_In:
|
752 | self._Next() # skip in
|
753 |
|
754 | in_spid = word.LeftMostSpanForWord(self.cur_word) + 1
|
755 | x = self.ParseForWords()
|
756 | if x is None:
|
757 | return None
|
758 | iter_words, semi_spid = x
|
759 | words2 = braces.BraceDetectAll(iter_words)
|
760 | words3 = word.TildeDetectAll(words2)
|
761 |
|
762 | if iter_words is None: # empty list of words is OK
|
763 | return None
|
764 | node.iter_words = words3
|
765 |
|
766 | elif self.c_id == Id.Op_Semi:
|
767 | node.do_arg_iter = True # implicit for loop
|
768 | self._Next()
|
769 |
|
770 | elif self.c_id == Id.KW_Do:
|
771 | node.do_arg_iter = True # implicit for loop
|
772 | # do not advance
|
773 |
|
774 | else:
|
775 | self.AddErrorContext("Unexpected word in for loop: %s", self.cur_word,
|
776 | word=self.cur_word)
|
777 | return None
|
778 |
|
779 | node.spids.extend((in_spid, semi_spid))
|
780 |
|
781 | body_node = self.ParseDoGroup()
|
782 | if not body_node: return None
|
783 |
|
784 | node.body = body_node
|
785 | return node
|
786 |
|
787 | def ParseFor(self):
|
788 | """
|
789 | for_clause : For for_name newline_ok (in for_words? for_sep)? do_group ;
|
790 | | For '((' ... TODO
|
791 | """
|
792 | if not self._Eat(Id.KW_For): return None
|
793 |
|
794 | if not self._Peek(): return None
|
795 | if self.c_id == Id.Op_DLeftParen:
|
796 | node = self._ParseForExprLoop()
|
797 | else:
|
798 | node = self._ParseForEachLoop()
|
799 |
|
800 | return node
|
801 |
|
802 | def ParseWhile(self):
|
803 | """
|
804 | while_clause : While command_list do_group ;
|
805 | """
|
806 | self._Next() # skip while
|
807 |
|
808 | cond_node = self.ParseCommandList()
|
809 | if not cond_node: return None
|
810 |
|
811 | body_node = self.ParseDoGroup()
|
812 | if not body_node: return None
|
813 |
|
814 | return ast.While(cond_node.children, body_node)
|
815 |
|
816 | def ParseUntil(self):
|
817 | """
|
818 | until_clause : Until command_list do_group ;
|
819 | """
|
820 | self._Next() # skip until
|
821 |
|
822 | cond_node = self.ParseCommandList()
|
823 | if not cond_node: return None
|
824 |
|
825 | body_node = self.ParseDoGroup()
|
826 | if not body_node: return None
|
827 |
|
828 | return ast.Until(cond_node.children, body_node)
|
829 |
|
830 | def ParseCaseItem(self):
|
831 | """
|
832 | case_item: '('? pattern ('|' pattern)* ')'
|
833 | newline_ok command_term? trailer? ;
|
834 | """
|
835 | self.lexer.PushHint(Id.Op_RParen, Id.Right_CasePat)
|
836 |
|
837 | left_spid = word.LeftMostSpanForWord(self.cur_word)
|
838 | if self.c_id == Id.Op_LParen:
|
839 | self._Next()
|
840 |
|
841 | pat_words = []
|
842 | while True:
|
843 | if not self._Peek(): return None
|
844 | pat_words.append(self.cur_word)
|
845 | self._Next()
|
846 |
|
847 | if not self._Peek(): return None
|
848 | if self.c_id == Id.Op_Pipe:
|
849 | self._Next()
|
850 | else:
|
851 | break
|
852 |
|
853 | rparen_spid = word.LeftMostSpanForWord(self.cur_word)
|
854 | if not self._Eat(Id.Right_CasePat): return None
|
855 | if not self._NewlineOk(): return None
|
856 |
|
857 | if self.c_id not in (Id.Op_DSemi, Id.KW_Esac):
|
858 | c_list = self.ParseCommandTerm()
|
859 | if not c_list: return None
|
860 | action_children = c_list.children
|
861 | else:
|
862 | action_children = []
|
863 |
|
864 | dsemi_spid = const.NO_INTEGER
|
865 | last_spid = const.NO_INTEGER
|
866 | if not self._Peek(): return None
|
867 | if self.c_id == Id.KW_Esac:
|
868 | last_spid = word.LeftMostSpanForWord(self.cur_word)
|
869 | elif self.c_id == Id.Op_DSemi:
|
870 | dsemi_spid = word.LeftMostSpanForWord(self.cur_word)
|
871 | self._Next()
|
872 | else:
|
873 | self.AddErrorContext('Expected DSEMI or ESAC, got %s', self.cur_word,
|
874 | word=self.cur_word)
|
875 | return None
|
876 |
|
877 | if not self._NewlineOk(): return None
|
878 |
|
879 | arm = ast.case_arm(pat_words, action_children)
|
880 | arm.spids.extend((left_spid, rparen_spid, dsemi_spid, last_spid))
|
881 | return arm
|
882 |
|
883 | def ParseCaseList(self, arms):
|
884 | """
|
885 | case_list: case_item (DSEMI newline_ok case_item)* DSEMI? newline_ok;
|
886 | """
|
887 | if not self._Peek(): return None
|
888 |
|
889 | while True:
|
890 | # case item begins with a command word or (
|
891 | if self.c_id == Id.KW_Esac:
|
892 | break
|
893 | if self.c_kind != Kind.Word and self.c_id != Id.Op_LParen:
|
894 | break
|
895 | arm = self.ParseCaseItem()
|
896 | if not arm: return None
|
897 |
|
898 | arms.append(arm)
|
899 | if not self._Peek(): return None
|
900 | # Now look for DSEMI or ESAC
|
901 |
|
902 | return True
|
903 |
|
904 | def ParseCase(self):
|
905 | """
|
906 | case_clause : Case WORD newline_ok in newline_ok case_list? Esac ;
|
907 | """
|
908 | case_node = ast.Case()
|
909 |
|
910 | case_spid = word.LeftMostSpanForWord(self.cur_word)
|
911 | self._Next() # skip case
|
912 |
|
913 | if not self._Peek(): return None
|
914 | case_node.to_match = self.cur_word
|
915 | self._Next()
|
916 |
|
917 | if not self._NewlineOk(): return None
|
918 | in_spid = word.LeftMostSpanForWord(self.cur_word)
|
919 | if not self._Eat(Id.KW_In): return None
|
920 | if not self._NewlineOk(): return None
|
921 |
|
922 | if self.c_id != Id.KW_Esac: # empty case list
|
923 | if not self.ParseCaseList(case_node.arms):
|
924 | self.AddErrorContext("ParseCase: error parsing case list")
|
925 | return None
|
926 | # TODO: should it return a list of nodes, and extend?
|
927 | if not self._Peek(): return None
|
928 |
|
929 | esac_spid = word.LeftMostSpanForWord(self.cur_word)
|
930 | if not self._Eat(Id.KW_Esac): return None
|
931 | self._Next()
|
932 |
|
933 | case_node.spids.extend((case_spid, in_spid, esac_spid))
|
934 | return case_node
|
935 |
|
936 | def _ParseElifElse(self, if_node):
|
937 | """
|
938 | else_part: (Elif command_list Then command_list)* Else command_list ;
|
939 | """
|
940 | arms = if_node.arms
|
941 |
|
942 | self._Peek()
|
943 | while self.c_id == Id.KW_Elif:
|
944 | elif_spid = word.LeftMostSpanForWord(self.cur_word)
|
945 |
|
946 | self._Next() # skip elif
|
947 | cond = self.ParseCommandList()
|
948 | if not cond: return None
|
949 |
|
950 | then_spid = word.LeftMostSpanForWord(self.cur_word)
|
951 | if not self._Eat(Id.KW_Then): return None
|
952 |
|
953 | body = self.ParseCommandList()
|
954 | if not body: return None
|
955 |
|
956 | arm = ast.if_arm(cond.children, body.children)
|
957 | arm.spids.extend((elif_spid, then_spid))
|
958 | arms.append(arm)
|
959 |
|
960 | if self.c_id == Id.KW_Else:
|
961 | else_spid = word.LeftMostSpanForWord(self.cur_word)
|
962 | self._Next()
|
963 | body = self.ParseCommandList()
|
964 | if not body: return None
|
965 | if_node.else_action = body.children
|
966 | else:
|
967 | else_spid = const.NO_INTEGER
|
968 |
|
969 | if_node.spids.append(else_spid)
|
970 |
|
971 | return True
|
972 |
|
973 | def ParseIf(self):
|
974 | """
|
975 | if_clause : If command_list Then command_list else_part? Fi ;
|
976 | """
|
977 | if_node = ast.If()
|
978 | self._Next() # skip if
|
979 |
|
980 | cond = self.ParseCommandList()
|
981 | if not cond: return None
|
982 |
|
983 | then_spid = word.LeftMostSpanForWord(self.cur_word)
|
984 | if not self._Eat(Id.KW_Then): return None
|
985 |
|
986 | body = self.ParseCommandList()
|
987 | if not body: return None
|
988 |
|
989 | arm = ast.if_arm(cond.children, body.children)
|
990 | arm.spids.extend((const.NO_INTEGER, then_spid)) # no if spid at first?
|
991 | if_node.arms.append(arm)
|
992 |
|
993 | if self.c_id in (Id.KW_Elif, Id.KW_Else):
|
994 | if not self._ParseElifElse(if_node):
|
995 | return None
|
996 | else:
|
997 | if_node.spids.append(const.NO_INTEGER) # no else spid
|
998 |
|
999 | fi_spid = word.LeftMostSpanForWord(self.cur_word)
|
1000 | if not self._Eat(Id.KW_Fi): return None
|
1001 |
|
1002 | if_node.spids.append(fi_spid)
|
1003 | return if_node
|
1004 |
|
1005 | def ParseTime(self):
|
1006 | """
|
1007 | time [-p] pipeline
|
1008 |
|
1009 | According to bash help.
|
1010 | """
|
1011 | self._Next() # skip time
|
1012 |
|
1013 | pipeline = self.ParsePipeline()
|
1014 | if not pipeline: return None
|
1015 | return ast.TimeBlock(pipeline)
|
1016 |
|
1017 | def ParseCompoundCommand(self):
|
1018 | """
|
1019 | compound_command : brace_group
|
1020 | | subshell
|
1021 | | for_clause
|
1022 | | while_clause
|
1023 | | until_clause
|
1024 | | if_clause
|
1025 | | case_clause
|
1026 | | time_clause
|
1027 | | [[ BoolExpr ]]
|
1028 | | (( ArithExpr ))
|
1029 | ;
|
1030 | """
|
1031 | if self.c_id == Id.Lit_LBrace:
|
1032 | return self.ParseBraceGroup()
|
1033 | if self.c_id == Id.Op_LParen:
|
1034 | return self.ParseSubshell()
|
1035 |
|
1036 | if self.c_id == Id.KW_For:
|
1037 | return self.ParseFor()
|
1038 | if self.c_id == Id.KW_While:
|
1039 | return self.ParseWhile()
|
1040 | if self.c_id == Id.KW_Until:
|
1041 | return self.ParseUntil()
|
1042 |
|
1043 | if self.c_id == Id.KW_If:
|
1044 | return self.ParseIf()
|
1045 | if self.c_id == Id.KW_Case:
|
1046 | return self.ParseCase()
|
1047 | if self.c_id == Id.KW_Time:
|
1048 | return self.ParseTime()
|
1049 |
|
1050 | # Example of redirect that is observable:
|
1051 | # $ (( $(echo one 1>&2; echo 2) > 0 )) 2> out.txt
|
1052 | if self.c_id == Id.KW_DLeftBracket:
|
1053 | return self.ParseDBracket()
|
1054 |
|
1055 | if self.c_id == Id.Op_DLeftParen:
|
1056 | return self.ParseDParen()
|
1057 |
|
1058 | self.AddErrorContext(
|
1059 | "Expected a compound command (e.g. for while if case), got %s",
|
1060 | self.cur_word, word=self.cur_word)
|
1061 | return None
|
1062 |
|
1063 | def ParseFunctionBody(self, func):
|
1064 | """
|
1065 | function_body : compound_command io_redirect* ; /* Apply rule 9 */
|
1066 | """
|
1067 | body = self.ParseCompoundCommand()
|
1068 | if not body: return None
|
1069 |
|
1070 | redirects = self._ParseRedirectList()
|
1071 | if redirects is None: return None
|
1072 |
|
1073 | func.body = body
|
1074 | func.redirects = redirects
|
1075 | return True
|
1076 |
|
1077 | def ParseFunctionDef(self):
|
1078 | """
|
1079 | function_header : fname '(' ')'
|
1080 | function_def : function_header newline_ok function_body ;
|
1081 |
|
1082 | Precondition: Looking at the function name.
|
1083 | Post condition:
|
1084 |
|
1085 | NOTE: There is an ambiguity with:
|
1086 |
|
1087 | function foo ( echo hi ) and
|
1088 | function foo () ( echo hi )
|
1089 |
|
1090 | Bash only accepts the latter, though it doesn't really follow a grammar.
|
1091 | """
|
1092 | left_spid = word.LeftMostSpanForWord(self.cur_word)
|
1093 |
|
1094 | ok, name = word.AsFuncName(self.cur_word)
|
1095 | if not ok:
|
1096 | self.AddErrorContext('Invalid function name', word=self.cur_word)
|
1097 | return None
|
1098 | self._Next() # skip function name
|
1099 |
|
1100 | # Must be true because of lookahead
|
1101 | if not self._Peek(): return None
|
1102 | assert self.c_id == Id.Op_LParen, self.cur_word
|
1103 |
|
1104 | self.lexer.PushHint(Id.Op_RParen, Id.Right_FuncDef)
|
1105 | self._Next()
|
1106 |
|
1107 | if not self._Eat(Id.Right_FuncDef): return None
|
1108 | after_name_spid = word.LeftMostSpanForWord(self.cur_word) + 1
|
1109 |
|
1110 | if not self._NewlineOk(): return None
|
1111 |
|
1112 | func = ast.FuncDef()
|
1113 | func.name = name
|
1114 |
|
1115 | if not self.ParseFunctionBody(func):
|
1116 | return None
|
1117 |
|
1118 | func.spids.append(left_spid)
|
1119 | func.spids.append(after_name_spid)
|
1120 | return func
|
1121 |
|
1122 | def ParseKshFunctionDef(self):
|
1123 | """
|
1124 | ksh_function_def : 'function' fname ( '(' ')' )? newline_ok function_body
|
1125 | """
|
1126 | left_spid = word.LeftMostSpanForWord(self.cur_word)
|
1127 |
|
1128 | self._Next() # skip past 'function'
|
1129 |
|
1130 | if not self._Peek(): return None
|
1131 | ok, name = word.AsFuncName(self.cur_word)
|
1132 | if not ok:
|
1133 | self.AddErrorContext("Invalid function name: %r", self.cur_word)
|
1134 | return None
|
1135 | after_name_spid = word.LeftMostSpanForWord(self.cur_word) + 1
|
1136 | self._Next() # skip past 'function name
|
1137 |
|
1138 | if not self._Peek(): return None
|
1139 | if self.c_id == Id.Op_LParen:
|
1140 | self.lexer.PushHint(Id.Op_RParen, Id.Right_FuncDef)
|
1141 | self._Next()
|
1142 | if not self._Eat(Id.Right_FuncDef): return None
|
1143 | # Change it: after )
|
1144 | after_name_spid = word.LeftMostSpanForWord(self.cur_word) + 1
|
1145 |
|
1146 | if not self._NewlineOk(): return None
|
1147 |
|
1148 | func = ast.FuncDef()
|
1149 | func.name = name
|
1150 |
|
1151 | if not self.ParseFunctionBody(func):
|
1152 | return None
|
1153 |
|
1154 | func.spids.append(left_spid)
|
1155 | func.spids.append(after_name_spid)
|
1156 | return func
|
1157 |
|
1158 | def ParseCoproc(self):
|
1159 | """
|
1160 | TODO:
|
1161 | """
|
1162 | raise NotImplementedError
|
1163 |
|
1164 | def ParseSubshell(self):
|
1165 | left_spid = word.LeftMostSpanForWord(self.cur_word)
|
1166 | self._Next() # skip past (
|
1167 |
|
1168 | # Ensure that something $( (cd / && pwd) ) works. If ) is already on the
|
1169 | # translation stack, we want to delay it.
|
1170 |
|
1171 | #print('ParseSubshell lexer.PushHint ) -> )')
|
1172 | self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
|
1173 |
|
1174 | c_list = self.ParseCommandList()
|
1175 | if not c_list: return None
|
1176 |
|
1177 | # Remove singleton CommandList as an optimization.
|
1178 | if len(c_list.children) == 1:
|
1179 | child = c_list.children[0]
|
1180 | else:
|
1181 | child = c_list
|
1182 | node = ast.Subshell(child)
|
1183 |
|
1184 | right_spid = word.LeftMostSpanForWord(self.cur_word)
|
1185 | if not self._Eat(Id.Right_Subshell): return None
|
1186 |
|
1187 | node.spids.extend((left_spid, right_spid))
|
1188 | return node
|
1189 |
|
1190 | def ParseDBracket(self):
|
1191 | """
|
1192 | Pass the underlying word parser off to the boolean expression parser.
|
1193 | """
|
1194 | maybe_error_word = self.cur_word
|
1195 | # TODO: Test interactive. Without closing ]], you should get > prompt
|
1196 | # (PS2)
|
1197 |
|
1198 | self._Next() # skip [[
|
1199 | b_parser = BoolParser(self.w_parser)
|
1200 | bnode = b_parser.Parse()
|
1201 | if not bnode:
|
1202 | error_stack = b_parser.Error()
|
1203 | self.error_stack.extend(error_stack)
|
1204 | self.AddErrorContext("Error parsing [[", word=maybe_error_word)
|
1205 | return None
|
1206 | return ast.DBracket(bnode)
|
1207 |
|
1208 | def ParseDParen(self):
|
1209 | maybe_error_word = self.cur_word
|
1210 | self._Next() # skip ((
|
1211 | #print('1 ((', self.cur_word)
|
1212 | anode = self.w_parser.ReadDParen()
|
1213 | if not anode:
|
1214 | error_stack = self.w_parser.Error()
|
1215 | self.error_stack.extend(error_stack)
|
1216 | self.AddErrorContext("Error parsing ((", word=maybe_error_word)
|
1217 | return None
|
1218 |
|
1219 | #print('2 ((', self.cur_word)
|
1220 | return ast.DParen(anode)
|
1221 |
|
1222 | def ParseCommand(self):
|
1223 | """
|
1224 | command : simple_command
|
1225 | | compound_command io_redirect*
|
1226 | | function_def
|
1227 | | ksh_function_def
|
1228 | ;
|
1229 | """
|
1230 | if not self._Peek(): return None
|
1231 |
|
1232 | if self.c_id == Id.KW_Function:
|
1233 | return self.ParseKshFunctionDef()
|
1234 |
|
1235 | if self.c_id in (
|
1236 | Id.KW_DLeftBracket, Id.Op_DLeftParen, Id.Op_LParen, Id.Lit_LBrace,
|
1237 | Id.KW_For, Id.KW_While, Id.KW_Until, Id.KW_If, Id.KW_Case, Id.KW_Time):
|
1238 | node = self.ParseCompoundCommand()
|
1239 | if not node: return None
|
1240 | if node.tag != command_e.TimeBlock: # The only one without redirects
|
1241 | redirects = self._ParseRedirectList()
|
1242 | if redirects is None:
|
1243 | return None
|
1244 | node.redirects = redirects
|
1245 | return node
|
1246 |
|
1247 | # NOTE: I added this to fix cases in parse-errors.test.sh, but it doesn't
|
1248 | # work because Lit_RBrace is in END_LIST below.
|
1249 |
|
1250 | # TODO: KW_Do is also invalid here.
|
1251 | if self.c_id == Id.Lit_RBrace:
|
1252 | self.AddErrorContext('Unexpected }', word=self.cur_word)
|
1253 | return None
|
1254 |
|
1255 | if self.c_kind == Kind.Redir: # Leading redirect
|
1256 | return self.ParseSimpleCommand()
|
1257 |
|
1258 | if self.c_kind == Kind.Word:
|
1259 | if self.w_parser.LookAhead() == Id.Op_LParen: # (
|
1260 | kov = word.LooksLikeAssignment(self.cur_word)
|
1261 | if kov:
|
1262 | return self.ParseSimpleCommand() # f=(a b c) # array
|
1263 | else:
|
1264 | return self.ParseFunctionDef() # f() { echo; } # function
|
1265 |
|
1266 | return self.ParseSimpleCommand() # echo foo
|
1267 |
|
1268 | self.AddErrorContext(
|
1269 | "ParseCommand: Expected to parse a command, got %s", self.cur_word,
|
1270 | word=self.cur_word)
|
1271 | return None
|
1272 |
|
1273 | def ParsePipeline(self):
|
1274 | """
|
1275 | pipeline : Bang? command ( '|' newline_ok command )* ;
|
1276 | """
|
1277 | negated = False
|
1278 |
|
1279 | if not self._Peek(): return None
|
1280 | if self.c_id == Id.KW_Bang:
|
1281 | negated = True
|
1282 | self._Next()
|
1283 |
|
1284 | child = self.ParseCommand()
|
1285 | if not child: return None
|
1286 |
|
1287 | children = [child]
|
1288 |
|
1289 | if not self._Peek(): return None
|
1290 | if self.c_id not in (Id.Op_Pipe, Id.Op_PipeAmp):
|
1291 | if negated:
|
1292 | node = ast.Pipeline(children, negated)
|
1293 | return node
|
1294 | else:
|
1295 | return child
|
1296 |
|
1297 | pipe_index = 0
|
1298 | stderr_indices = []
|
1299 |
|
1300 | if self.c_id == Id.Op_PipeAmp:
|
1301 | stderr_indices.append(pipe_index)
|
1302 | pipe_index += 1
|
1303 |
|
1304 | while True:
|
1305 | self._Next() # skip past Id.Op_Pipe or Id.Op_PipeAmp
|
1306 |
|
1307 | if not self._NewlineOk():
|
1308 | return None
|
1309 |
|
1310 | child = self.ParseCommand()
|
1311 | if not child:
|
1312 | self.AddErrorContext('Error parsing command after pipe')
|
1313 | # TODO: Return partial pipeline here? All signatures should (ok,
|
1314 | # node). Only the completion uses the node when ok is False.
|
1315 | return None
|
1316 | children.append(child)
|
1317 |
|
1318 | if not self._Peek(): return None
|
1319 | if self.c_id not in (Id.Op_Pipe, Id.Op_PipeAmp):
|
1320 | break
|
1321 |
|
1322 | if self.c_id == Id.Op_PipeAmp:
|
1323 | stderr_indices.append(pipe_index)
|
1324 | pipe_index += 1
|
1325 |
|
1326 | node = ast.Pipeline(children, negated)
|
1327 | node.stderr_indices = stderr_indices
|
1328 | return node
|
1329 |
|
1330 | def ParseAndOr(self):
|
1331 | """
|
1332 | and_or : and_or ( AND_IF | OR_IF ) newline_ok pipeline
|
1333 | | pipeline
|
1334 |
|
1335 | Note that it is left recursive and left associative. We parse it
|
1336 | iteratively with a token of lookahead.
|
1337 | """
|
1338 | child = self.ParsePipeline()
|
1339 | if not child: return None
|
1340 |
|
1341 | if not self._Peek(): return None
|
1342 | if self.c_id not in (Id.Op_DPipe, Id.Op_DAmp):
|
1343 | return child
|
1344 |
|
1345 | ops = []
|
1346 | children = [child]
|
1347 |
|
1348 | while True:
|
1349 | ops.append(self.c_id)
|
1350 |
|
1351 | self._Next() # skip past || &&
|
1352 |
|
1353 | if not self._NewlineOk():
|
1354 | return None
|
1355 |
|
1356 | child = self.ParsePipeline()
|
1357 | if not child: return None
|
1358 |
|
1359 | children.append(child)
|
1360 |
|
1361 | if not self._Peek(): return None
|
1362 | if self.c_id not in (Id.Op_DPipe, Id.Op_DAmp):
|
1363 | break
|
1364 |
|
1365 | node = ast.AndOr(ops, children)
|
1366 | return node
|
1367 |
|
1368 | def ParseCommandLine(self):
|
1369 | """
|
1370 | NOTE: This is only called in InteractiveLoop. Oh crap I need to really
|
1371 | read and execute a line at a time then?
|
1372 |
|
1373 | BUG: sleep 1 & sleep 1 & doesn't work here, when written in REPL. But it
|
1374 | does work with '-c', because that calls ParseFile and not ParseCommandLine
|
1375 | over and over.
|
1376 |
|
1377 | TODO: Get rid of ParseFile and stuff? Shouldn't be used for -c and so
|
1378 | forth. Just have an ExecuteLoop for now. But you still need
|
1379 | ParseCommandList, for internal nodes.
|
1380 |
|
1381 | command_line : and_or (sync_op and_or)* trailer? ;
|
1382 | trailer : sync_op newline_ok
|
1383 | | NEWLINES;
|
1384 | sync_op : '&' | ';';
|
1385 |
|
1386 | This rule causes LL(k > 1) behavior. We would have to peek to see if there
|
1387 | is another command word after the sync op.
|
1388 |
|
1389 | But it's easier to express imperatively. Do the following in a loop:
|
1390 | 1. ParseAndOr
|
1391 | 2. Peek.
|
1392 | a. If there's a newline, then return. (We're only parsing a single
|
1393 | line.)
|
1394 | b. If there's a sync_op, process it. Then look for a newline and
|
1395 | return. Otherwise, parse another AndOr.
|
1396 |
|
1397 | COMPARE
|
1398 | command_line : and_or (sync_op and_or)* trailer? ; # TOP LEVEL
|
1399 | command_term : and_or (trailer and_or)* ; # CHILDREN
|
1400 |
|
1401 | I think you should be able to factor these out.
|
1402 | """
|
1403 | children = []
|
1404 | done = False
|
1405 | while not done:
|
1406 | child = self.ParseAndOr()
|
1407 | if not child: return None
|
1408 |
|
1409 | if not self._Peek(): return None
|
1410 | if self.c_id in (Id.Op_Semi, Id.Op_Amp): # also Id.Op_Amp.
|
1411 | child = ast.Sentence(child, self.cur_word.token)
|
1412 | self._Next()
|
1413 |
|
1414 | if not self._Peek(): return None
|
1415 | if self.c_id in (Id.Op_Newline, Id.Eof_Real):
|
1416 | done = True
|
1417 |
|
1418 | elif self.c_id == Id.Op_Newline:
|
1419 | done = True
|
1420 |
|
1421 | elif self.c_id == Id.Eof_Real:
|
1422 | done = True
|
1423 |
|
1424 | else:
|
1425 | self.AddErrorContext(
|
1426 | 'ParseCommandLine: Unexpected token %s', self.cur_word)
|
1427 | return None
|
1428 |
|
1429 | children.append(child)
|
1430 |
|
1431 | return ast.CommandList(children)
|
1432 |
|
1433 | def ParseCommandTerm(self):
|
1434 | """"
|
1435 | command_term : and_or (trailer and_or)* ;
|
1436 | trailer : sync_op newline_ok
|
1437 | | NEWLINES;
|
1438 | sync_op : '&' | ';';
|
1439 |
|
1440 | This is handled in imperative style, like ParseCommandLine.
|
1441 | Called by ParseCommandList for all blocks, and also for ParseCaseItem,
|
1442 | which is slightly different. (HOW? Is it the DSEMI?)
|
1443 |
|
1444 | Returns:
|
1445 | ast.command
|
1446 | """
|
1447 | # Word types that will end the command term.
|
1448 | END_LIST = (
|
1449 | Id.Eof_Real, Id.Eof_RParen, Id.Eof_Backtick, Id.Right_Subshell,
|
1450 | Id.Lit_RBrace, Id.Op_DSemi)
|
1451 |
|
1452 | # NOTE: This is similar to ParseCommandLine, except there is a lot of stuff
|
1453 | # about here docs. Here docs are inherently line-oriented.
|
1454 | #
|
1455 | # - Why aren't we doing END_LIST in ParseCommandLine?
|
1456 | # - Because you will never be inside $() at the top level.
|
1457 | # - We also know it will end in a newline. It can't end in "fi"!
|
1458 | # - example: if true; then { echo hi; } fi
|
1459 | # - Why aren't we doing 'for c in children' too?
|
1460 |
|
1461 | children = []
|
1462 | done = False
|
1463 | while not done:
|
1464 | if not self._Peek(): return None
|
1465 | #print('====> ParseCommandTerm word', self.cur_word)
|
1466 |
|
1467 | # Most keywords are valid "first words". But do/done/then do not BEGIN
|
1468 | # commands, so they are not valid.
|
1469 | if self.c_id in (
|
1470 | Id.KW_Do, Id.KW_Done, Id.KW_Then, Id.KW_Fi, Id.KW_Elif, Id.KW_Else,
|
1471 | Id.KW_Esac):
|
1472 | break
|
1473 |
|
1474 | child = self.ParseAndOr()
|
1475 | if not child:
|
1476 | self.AddErrorContext('Error parsing AndOr in ParseCommandTerm')
|
1477 | return None
|
1478 |
|
1479 | if not self._Peek(): return None
|
1480 | if self.c_id == Id.Op_Newline:
|
1481 | self._Next()
|
1482 |
|
1483 | if not self._Peek(): return None
|
1484 | if self.c_id in END_LIST:
|
1485 | done = True
|
1486 |
|
1487 | elif self.c_id in (Id.Op_Semi, Id.Op_Amp):
|
1488 | child = ast.Sentence(child, self.cur_word.token)
|
1489 | self._Next()
|
1490 |
|
1491 | if not self._Peek(): return None
|
1492 | if self.c_id == Id.Op_Newline:
|
1493 | self._Next() # skip over newline
|
1494 |
|
1495 | # Test if we should keep going. There might be another command after
|
1496 | # the semi and newline.
|
1497 | if not self._Peek(): return None
|
1498 | if self.c_id in END_LIST:
|
1499 | done = True
|
1500 |
|
1501 | elif self.c_id in END_LIST: # ; EOF
|
1502 | done = True
|
1503 |
|
1504 | elif self.c_id in END_LIST: # EOF
|
1505 | done = True
|
1506 |
|
1507 | else:
|
1508 | pass # e.g. "} done", "fi fi", ") fi", etc. is OK
|
1509 |
|
1510 | children.append(child)
|
1511 |
|
1512 | if not self._Peek(): return None
|
1513 |
|
1514 | return ast.CommandList(children)
|
1515 |
|
1516 | def ParseCommandList(self):
|
1517 | """
|
1518 | command_list : newline_ok command_term trailer? ;
|
1519 |
|
1520 | This one is called by all the compound commands. It's basically a command
|
1521 | block.
|
1522 |
|
1523 | NOTE: Rather than translating the CFG directly, the code follows a style
|
1524 | more like this: more like this: (and_or trailer)+. It makes capture
|
1525 | easier.
|
1526 | """
|
1527 | if not self._NewlineOk(): return None
|
1528 |
|
1529 | node = self.ParseCommandTerm()
|
1530 | if node is None: return None
|
1531 | assert node is not False
|
1532 | return node
|
1533 |
|
1534 | def ParseWholeFile(self):
|
1535 | """Entry point for main() in non-interactive shell.
|
1536 |
|
1537 | Very similar to ParseCommandList, but we allow empty files.
|
1538 |
|
1539 | TODO: This should be turned into a Parse and Execute loop, freeing arenas
|
1540 | if they don't contain functions.
|
1541 | """
|
1542 | if not self._NewlineOk(): return None
|
1543 |
|
1544 | #print('ParseFile', self.c_kind, self.cur_word)
|
1545 | # An empty node to execute
|
1546 | if self.c_kind == Kind.Eof:
|
1547 | return ast.NoOp()
|
1548 |
|
1549 | # This calls ParseAndOr(), but I think it should be a loop that calls
|
1550 | # ParseCommandLine(), like oil.InteractiveLoop.
|
1551 | node = self.ParseCommandTerm()
|
1552 | if node is None: return None
|
1553 | assert node is not False
|
1554 |
|
1555 | return node
|