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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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6 ** |
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7 ** This file is part of the QtScript module of the Qt Toolkit. |
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8 ** |
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9 ** $QT_BEGIN_LICENSE:LGPL$ |
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10 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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15 ** |
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16 ** GNU Lesser General Public License Usage |
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17 ** Alternatively, this file may be used under the terms of the GNU Lesser |
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18 ** General Public License version 2.1 as published by the Free Software |
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19 ** Foundation and appearing in the file LICENSE.LGPL included in the |
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20 ** packaging of this file. Please review the following information to |
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21 ** ensure the GNU Lesser General Public License version 2.1 requirements |
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22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
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23 ** |
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24 ** In addition, as a special exception, Nokia gives you certain additional |
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25 ** rights. These rights are described in the Nokia Qt LGPL Exception |
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26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
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27 ** |
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28 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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30 ** |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 #include "qscriptsyntaxchecker_p.h" |
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43 |
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44 #include "qscriptlexer_p.h" |
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45 #include "qscriptparser_p.h" |
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46 |
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47 QT_BEGIN_NAMESPACE |
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48 |
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49 namespace QScript { |
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50 |
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51 |
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52 SyntaxChecker::SyntaxChecker(): |
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53 tos(0), |
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54 stack_size(0), |
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55 state_stack(0) |
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56 { |
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57 } |
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58 |
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59 SyntaxChecker::~SyntaxChecker() |
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60 { |
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61 if (stack_size) { |
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62 qFree(state_stack); |
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63 } |
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64 } |
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65 |
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66 bool SyntaxChecker::automatic(QScript::Lexer *lexer, int token) const |
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67 { |
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68 return token == T_RBRACE || token == 0 || lexer->prevTerminator(); |
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69 } |
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70 |
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71 SyntaxChecker::Result SyntaxChecker::checkSyntax(const QString &code) |
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72 { |
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73 const int INITIAL_STATE = 0; |
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74 QScript::Lexer lexer (/*engine=*/ 0); |
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75 lexer.setCode(code, /*lineNo*/ 1); |
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76 |
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77 int yytoken = -1; |
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78 int saved_yytoken = -1; |
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79 QString error_message; |
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80 int error_lineno = -1; |
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81 int error_column = -1; |
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82 State checkerState = Valid; |
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83 |
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84 reallocateStack(); |
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85 |
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86 tos = 0; |
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87 state_stack[++tos] = INITIAL_STATE; |
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88 |
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89 while (true) |
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90 { |
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91 const int state = state_stack [tos]; |
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92 if (yytoken == -1 && - TERMINAL_COUNT != action_index [state]) |
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93 { |
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94 if (saved_yytoken == -1) |
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95 yytoken = lexer.lex(); |
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96 else |
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97 { |
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98 yytoken = saved_yytoken; |
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99 saved_yytoken = -1; |
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100 } |
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101 } |
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102 |
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103 int act = t_action (state, yytoken); |
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104 |
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105 if (act == ACCEPT_STATE) { |
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106 if (lexer.error() == QScript::Lexer::UnclosedComment) |
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107 checkerState = Intermediate; |
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108 else |
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109 checkerState = Valid; |
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110 break; |
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111 } else if (act > 0) { |
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112 if (++tos == stack_size) |
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113 reallocateStack(); |
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114 |
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115 state_stack [tos] = act; |
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116 yytoken = -1; |
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117 } |
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118 |
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119 else if (act < 0) |
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120 { |
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121 int r = - act - 1; |
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122 |
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123 tos -= rhs [r]; |
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124 act = state_stack [tos++]; |
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125 |
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126 if ((r == Q_SCRIPT_REGEXPLITERAL_RULE1) |
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127 || (r == Q_SCRIPT_REGEXPLITERAL_RULE2)) { |
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128 // Skip the rest of the RegExp literal |
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129 bool rx = lexer.scanRegExp(); |
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130 if (!rx) { |
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131 checkerState = Intermediate; |
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132 break; |
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133 } |
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134 } |
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135 |
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136 state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT); |
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137 } |
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138 |
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139 else |
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140 { |
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141 if (saved_yytoken == -1 && automatic (&lexer, yytoken) && t_action (state, T_AUTOMATIC_SEMICOLON) > 0) |
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142 { |
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143 saved_yytoken = yytoken; |
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144 yytoken = T_SEMICOLON; |
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145 continue; |
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146 } |
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147 |
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148 else if ((state == INITIAL_STATE) && (yytoken == 0)) { |
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149 // accept empty input |
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150 yytoken = T_SEMICOLON; |
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151 continue; |
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152 } |
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153 |
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154 int ers = state; |
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155 int shifts = 0; |
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156 int reduces = 0; |
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157 int expected_tokens [3]; |
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158 for (int tk = 0; tk < TERMINAL_COUNT; ++tk) |
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159 { |
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160 int k = t_action (ers, tk); |
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161 |
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162 if (! k) |
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163 continue; |
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164 else if (k < 0) |
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165 ++reduces; |
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166 else if (spell [tk]) |
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167 { |
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168 if (shifts < 3) |
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169 expected_tokens [shifts] = tk; |
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170 ++shifts; |
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171 } |
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172 } |
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173 |
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174 error_message.clear (); |
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175 if (shifts && shifts < 3) |
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176 { |
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177 bool first = true; |
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178 |
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179 for (int s = 0; s < shifts; ++s) |
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180 { |
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181 if (first) |
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182 error_message += QLatin1String ("Expected "); |
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183 else |
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184 error_message += QLatin1String (", "); |
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185 |
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186 first = false; |
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187 error_message += QLatin1Char('`'); |
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188 error_message += QLatin1String (spell [expected_tokens [s]]); |
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189 error_message += QLatin1Char('\''); |
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190 } |
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191 } |
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192 |
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193 if (error_message.isEmpty()) |
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194 error_message = lexer.errorMessage(); |
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195 |
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196 error_lineno = lexer.startLineNo(); |
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197 error_column = lexer.startColumnNo(); |
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198 checkerState = Error; |
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199 break; |
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200 } |
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201 } |
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202 |
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203 if (checkerState == Error) { |
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204 if (lexer.error() == QScript::Lexer::UnclosedComment) |
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205 checkerState = Intermediate; |
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206 else if (yytoken == 0) |
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207 checkerState = Intermediate; |
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208 } |
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209 return Result(checkerState, error_lineno, error_column, error_message); |
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210 } |
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211 |
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212 } // namespace QScript |
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213 |
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214 QT_END_NAMESPACE |