1 | """expr_parse.py."""
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2 | from __future__ import print_function
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3 |
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4 | from _devbuild.gen.syntax_asdl import (loc, Token, DoubleQuoted, SingleQuoted,
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5 | CommandSub, ShArrayLiteral,
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6 | CompoundWord, word_part_t, word_e)
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7 | from _devbuild.gen.id_kind_asdl import Id, Kind, Id_str
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8 | from _devbuild.gen.types_asdl import lex_mode_e
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9 |
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10 | from core import ui
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11 | from core.error import p_die
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12 | from frontend import consts
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13 | from frontend import lexer
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14 | from frontend import reader
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15 | from mycpp import mylib
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16 | from mycpp.mylib import log, tagswitch
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17 | from osh import braces
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18 | from osh import word_
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19 | from osh import word_compile
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20 | from pgen2 import parse
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21 | from pgen2.pnode import PNodeAllocator
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22 |
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23 | _ = log
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24 |
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25 | from typing import TYPE_CHECKING, Any, Dict, Tuple, List, cast, Optional
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26 | if TYPE_CHECKING:
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27 | from frontend.lexer import Lexer
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28 | from frontend.parse_lib import ParseContext
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29 | from pgen2.grammar import Grammar
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30 | from pgen2.pnode import PNode
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31 |
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32 | if mylib.PYTHON:
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33 |
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34 | class ParseTreePrinter(object):
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35 | """Prints a tree of PNode instances."""
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36 |
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37 | def __init__(self, names):
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38 | # type: (Dict[int, str]) -> None
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39 | self.names = names
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40 | self.f = mylib.Stdout()
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41 |
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42 | def _Print(self, pnode, indent, i):
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43 | # type: (PNode, int, int) -> None
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44 |
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45 | ind = ' ' * indent
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46 | # NOTE:
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47 | # - why isn't 'tok' None for PRODUCTIONS? There is some redundancy to get
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48 | # rid of.
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49 | if pnode.tok:
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50 | if isinstance(pnode.tok, Token):
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51 | v = lexer.TokenVal(pnode.tok)
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52 | else:
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53 | # e.g. CommandSub for x = $(echo hi)
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54 | v = repr(pnode.tok)
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55 | else:
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56 | v = '-'
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57 | self.f.write('%s%d %s %s\n' % (ind, i, self.names[pnode.typ], v))
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58 | if pnode.children is not None:
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59 | for i, child in enumerate(pnode.children):
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60 | self._Print(child, indent + 1, i)
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61 |
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62 | def Print(self, pnode):
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63 | # type: (PNode) -> None
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64 | self._Print(pnode, 0, 0)
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65 |
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66 |
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67 | def _Classify(gr, tok):
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68 | # type: (Grammar, Token) -> int
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69 |
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70 | # We have to match up what ParserGenerator.make_grammar() did when
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71 | # calling make_label() and make_first(). See classify() in
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72 | # opy/pgen2/driver.py.
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73 |
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74 | id_ = tok.id # mycpp fix: we need C++ to do uint16_t -> int conversion
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75 |
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76 | # TODO: use something more efficient than a Dict
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77 | if id_ in gr.tokens:
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78 | return gr.tokens[id_]
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79 |
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80 | if id_ == Id.Unknown_DEqual:
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81 | p_die('Use === to be exact, or ~== to convert types', tok)
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82 |
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83 | if id_ == Id.Unknown_Tok:
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84 | type_str = ''
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85 | else:
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86 | type_str = ' (%s)' % ui.PrettyId(tok.id)
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87 | p_die('Unexpected token in expression mode%s' % type_str, tok)
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88 |
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89 |
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90 | # Newlines are ignored between these pairs.
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91 | # yapf: disable
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92 | _OTHER_BALANCE = {
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93 |
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94 | # Parenthesized expressions (tuples) and func/proc parameter lists
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95 | Id.Op_LParen: 1,
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96 | Id.Op_RParen: -1,
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97 | Id.Op_LBracket: 1,
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98 | Id.Op_RBracket: -1,
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99 |
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100 | # Dicts are {}, and the grammar respects Op_Newline.
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101 | }
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102 | # yapf: enable
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103 |
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104 |
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105 | def _PushYshTokens(parse_ctx, gr, p, lex):
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106 | # type: (ParseContext, Grammar, parse.Parser, Lexer) -> Token
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107 | """Push tokens onto pgen2's parser.
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108 |
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109 | Returns the last token so it can be reused/seen by the CommandParser.
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110 | """
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111 | #log('keywords = %s', gr.keywords)
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112 | #log('tokens = %s', gr.tokens)
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113 |
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114 | last_token = None # type: Optional[Token]
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115 | prev_was_newline = False
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116 |
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117 | balance = 0 # to ignore newlines
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118 |
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119 | while True:
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120 | if last_token: # e.g. left over from WordParser
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121 | tok = last_token
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122 | #log('last_token = %s', last_token)
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123 | last_token = None
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124 | else:
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125 | tok = lex.Read(lex_mode_e.Expr)
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126 | #log('tok = %s', tok)
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127 |
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128 | # Comments and whitespace. Newlines aren't ignored.
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129 | if consts.GetKind(tok.id) == Kind.Ignored:
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130 | continue
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131 |
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132 | # For multiline lists, maps, etc.
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133 | if tok.id == Id.Op_Newline:
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134 | if balance > 0:
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135 | #log('*** SKIPPING NEWLINE')
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136 | continue
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137 | # Eliminate duplicate newline tokens. It makes the grammar simpler, and
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138 | # it's consistent with CPython's lexer and our own WordParser.
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139 | if prev_was_newline:
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140 | continue
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141 | prev_was_newline = True
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142 | else:
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143 | prev_was_newline = False
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144 |
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145 | balance += _OTHER_BALANCE.get(tok.id, 0)
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146 | #log('BALANCE after seeing %s = %d', tok.id, balance)
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147 |
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148 | if tok.id == Id.Op_LParen:
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149 | # For nesting inside $()
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150 | lex.PushHint(Id.Op_RParen, Id.Op_RParen)
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151 |
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152 | #if tok.id == Id.Expr_Name and tok.val in KEYWORDS:
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153 | # tok.id = KEYWORDS[tok.val]
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154 | # log('Replaced with %s', tok.id)
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155 |
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156 | assert tok.id < 256, Id_str(tok.id)
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157 |
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158 | ilabel = _Classify(gr, tok)
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159 | #log('tok = %s, ilabel = %d', tok, ilabel)
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160 |
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161 | if p.addtoken(tok.id, tok, ilabel):
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162 | return tok
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163 |
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164 | #
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165 | # Mututally recursive calls into the command/word parsers.
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166 | #
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167 |
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168 | if tok.id in (Id.Left_ColonPipe,
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169 | Id.Left_PercentParen): # :| %( LEGACY!
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170 | left_tok = tok
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171 | if tok.id == Id.Left_PercentParen:
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172 | lex.PushHint(Id.Op_RParen, Id.Right_ShArrayLiteral)
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173 |
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174 | # Blame the opening token
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175 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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176 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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177 | words = [] # type: List[CompoundWord]
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178 | close_tok = None # type: Optional[Token]
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179 | done = False
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180 | while not done:
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181 | w = w_parser.ReadWord(lex_mode_e.ShCommand)
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182 | with tagswitch(w) as case:
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183 | if case(word_e.Operator):
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184 | tok = cast(Token, w)
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185 | if tok.id == Id.Right_ShArrayLiteral:
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186 | if left_tok.id != Id.Left_PercentParen:
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187 | p_die('Expected ) to close', left_tok)
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188 | close_tok = tok
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189 | done = True # can't use break here
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190 | elif tok.id == Id.Op_Pipe:
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191 | if left_tok.id != Id.Left_ColonPipe:
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192 | p_die('Expected ) to close', left_tok)
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193 | close_tok = tok
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194 | done = True # can't use break here
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195 | elif tok.id == Id.Op_Newline: # internal newlines allowed
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196 | continue
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197 | else:
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198 | p_die('Unexpected token in array literal',
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199 | loc.Word(w))
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200 |
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201 | elif case(word_e.Compound):
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202 | words.append(cast(CompoundWord, w))
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203 |
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204 | else:
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205 | raise AssertionError()
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206 |
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207 | words2 = braces.BraceDetectAll(words)
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208 | words3 = word_.TildeDetectAll(words2)
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209 |
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210 | typ = Id.Expr_CastedDummy
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211 |
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212 | lit_part = ShArrayLiteral(left_tok, words3, close_tok)
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213 | opaque = cast(Token, lit_part) # HACK for expr_to_ast
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214 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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215 | assert not done # can't end the expression
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216 |
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217 | # Now push the closing )
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218 | ilabel = _Classify(gr, close_tok)
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219 | done = p.addtoken(tok.id, close_tok, ilabel)
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220 | assert not done # can't end the expression
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221 |
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222 | continue
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223 |
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224 | # $( @( ^(
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225 | if tok.id in (Id.Left_DollarParen, Id.Left_AtParen,
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226 | Id.Left_CaretParen):
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227 |
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228 | left_token = tok
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229 |
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230 | lex.PushHint(Id.Op_RParen, Id.Eof_RParen)
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231 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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232 | c_parser = parse_ctx.MakeParserForCommandSub(
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233 | line_reader, lex, Id.Eof_RParen)
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234 | node = c_parser.ParseCommandSub()
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235 | # A little gross: Copied from osh/word_parse.py
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236 | right_token = c_parser.w_parser.cur_token
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237 |
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238 | cs_part = CommandSub(left_token, node, right_token)
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239 |
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240 | typ = Id.Expr_CastedDummy
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241 | opaque = cast(Token, cs_part) # HACK for expr_to_ast
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242 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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243 | assert not done # can't end the expression
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244 |
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245 | # Now push the closing )
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246 | ilabel = _Classify(gr, right_token)
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247 | done = p.addtoken(right_token.id, right_token, ilabel)
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248 | assert not done # can't end the expression
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249 |
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250 | continue
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251 |
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252 | # " $" """ $""" ^"
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253 | if tok.id in (Id.Left_DoubleQuote, Id.Left_DollarDoubleQuote,
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254 | Id.Left_TDoubleQuote, Id.Left_DollarTDoubleQuote,
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255 | Id.Left_CaretDoubleQuote):
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256 |
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257 | left_token = tok
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258 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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259 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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260 |
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261 | parts = [] # type: List[word_part_t]
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262 | last_token = w_parser.ReadDoubleQuoted(left_token, parts)
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263 | expr_dq_part = DoubleQuoted(left_token, parts, last_token)
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264 |
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265 | typ = Id.Expr_CastedDummy
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266 | opaque = cast(Token, expr_dq_part) # HACK for expr_to_ast
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267 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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268 | assert not done # can't end the expression
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269 |
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270 | continue
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271 |
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272 | # ${
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273 | if tok.id == Id.Left_DollarBrace:
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274 | left_token = tok
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275 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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276 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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277 |
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278 | part, last_token = w_parser.ReadBracedVarSub(left_token)
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279 |
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280 | # It's casted word_part.BracedVarSub -> dummy -> expr.BracedVarSub!
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281 | typ = Id.Expr_CastedDummy
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282 | opaque = cast(Token, part) # HACK for expr_to_ast
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283 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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284 | assert not done # can't end the expression
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285 |
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286 | continue
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287 |
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288 | # 'x' '''x'''
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289 | # r'x' r'''x'''
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290 | # u'x' u'''x'''
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291 | # b'x' b'''x'''
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292 | # $'x'
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293 | if tok.id in (Id.Left_SingleQuote, Id.Left_TSingleQuote,
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294 | Id.Left_RSingleQuote, Id.Left_RTSingleQuote,
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295 | Id.Left_USingleQuote, Id.Left_UTSingleQuote,
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296 | Id.Left_BSingleQuote, Id.Left_BTSingleQuote,
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297 | Id.Left_DollarSingleQuote):
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298 | if tok.id == Id.Left_DollarSingleQuote:
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299 | sq_mode = lex_mode_e.SQ_C
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300 | elif tok.id in (Id.Left_USingleQuote, Id.Left_UTSingleQuote,
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301 | Id.Left_BSingleQuote, Id.Left_BTSingleQuote):
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302 | sq_mode = lex_mode_e.J8_Str
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303 | else:
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304 | sq_mode = lex_mode_e.SQ_Raw
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305 |
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306 | left_token = tok
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307 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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308 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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309 |
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310 | tokens = [] # type: List[Token]
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311 | last_token = w_parser.ReadSingleQuoted(sq_mode, left_token, tokens,
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312 | True)
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313 |
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314 | sval = word_compile.EvalSingleQuoted(left_token.id, tokens)
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315 | sq_part = SingleQuoted(left_token, sval, last_token)
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316 |
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317 | typ = Id.Expr_CastedDummy
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318 | opaque = cast(Token, sq_part) # HACK for expr_to_ast
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319 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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320 | assert not done # can't end the expression
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321 | continue
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322 |
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323 | else:
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324 | # We never broke out -- EOF is too soon (how can this happen???)
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325 | raise parse.ParseError("incomplete input", tok.id, tok)
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326 |
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327 |
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328 | class ExprParser(object):
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329 | """A wrapper around a pgen2 parser."""
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330 |
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331 | def __init__(self, parse_ctx, gr):
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332 | # type: (ParseContext, Grammar) -> None
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333 | self.parse_ctx = parse_ctx
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334 | self.gr = gr
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335 | # Reused multiple times.
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336 | self.push_parser = parse.Parser(gr)
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337 | self.pnode_alloc = None # type: Optional[PNodeAllocator]
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338 |
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339 | def Parse(self, lexer, start_symbol):
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340 | # type: (Lexer, int) -> Tuple[PNode, Token]
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341 |
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342 | # Reuse the parser
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343 | self.push_parser.setup(start_symbol, self.pnode_alloc)
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344 | try:
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345 | last_token = _PushYshTokens(self.parse_ctx, self.gr,
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346 | self.push_parser, lexer)
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347 | except parse.ParseError as e:
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348 | #log('ERROR %s', e)
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349 | # TODO:
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350 | # - Describe what lexer mode we're in (Invalid syntax in regex)
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351 | # - Maybe say where the mode started
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352 | # - Id.Unknown_Tok could say "This character is invalid"
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353 |
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354 | # ParseError has a "too much input" case but I haven't been able to
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355 | # tickle it. Maybe it's because of the Eof tokens?
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356 |
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357 | p_die(
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358 | 'Syntax error in expression (near %s)' % ui.PrettyId(e.tok.id),
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359 | e.tok)
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360 |
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361 | return self.push_parser.rootnode, last_token
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362 |
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363 |
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364 | class ctx_PNodeAllocator(object):
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365 |
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366 | def __init__(self, ep):
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367 | # type: (ExprParser) -> None
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368 | self.expr_parser = ep
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369 | self.expr_parser.pnode_alloc = PNodeAllocator()
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370 |
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371 | def __enter__(self):
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372 | # type: () -> None
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373 | pass
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374 |
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375 | def __exit__(self, type, value, traceback):
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376 | # type: (Any, Any, Any) -> None
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377 | self.expr_parser.pnode_alloc.Clear()
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378 | self.expr_parser.pnode_alloc = None
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