1 | /**
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2 | * @fileoverview A class to manage state of generating a code path.
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3 | * @author Toru Nagashima
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4 | */
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5 |
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6 | ;
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7 |
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8 | //------------------------------------------------------------------------------
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9 | // Requirements
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10 | //------------------------------------------------------------------------------
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11 |
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12 | const CodePathSegment = require("./code-path-segment"),
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13 | ForkContext = require("./fork-context");
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14 |
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15 | //------------------------------------------------------------------------------
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16 | // Helpers
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17 | //------------------------------------------------------------------------------
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18 |
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19 | /**
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20 | * Adds given segments into the `dest` array.
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21 | * If the `others` array does not includes the given segments, adds to the `all`
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22 | * array as well.
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23 | *
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24 | * This adds only reachable and used segments.
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25 | * @param {CodePathSegment[]} dest A destination array (`returnedSegments` or `thrownSegments`).
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26 | * @param {CodePathSegment[]} others Another destination array (`returnedSegments` or `thrownSegments`).
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27 | * @param {CodePathSegment[]} all The unified destination array (`finalSegments`).
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28 | * @param {CodePathSegment[]} segments Segments to add.
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29 | * @returns {void}
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30 | */
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31 | function addToReturnedOrThrown(dest, others, all, segments) {
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32 | for (let i = 0; i < segments.length; ++i) {
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33 | const segment = segments[i];
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34 |
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35 | dest.push(segment);
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36 | if (others.indexOf(segment) === -1) {
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37 | all.push(segment);
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38 | }
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39 | }
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40 | }
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41 |
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42 | /**
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43 | * Gets a loop-context for a `continue` statement.
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44 | * @param {CodePathState} state A state to get.
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45 | * @param {string} label The label of a `continue` statement.
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46 | * @returns {LoopContext} A loop-context for a `continue` statement.
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47 | */
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48 | function getContinueContext(state, label) {
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49 | if (!label) {
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50 | return state.loopContext;
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51 | }
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52 |
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53 | let context = state.loopContext;
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54 |
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55 | while (context) {
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56 | if (context.label === label) {
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57 | return context;
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58 | }
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59 | context = context.upper;
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60 | }
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61 |
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62 | /* istanbul ignore next: foolproof (syntax error) */
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63 | return null;
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64 | }
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65 |
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66 | /**
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67 | * Gets a context for a `break` statement.
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68 | * @param {CodePathState} state A state to get.
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69 | * @param {string} label The label of a `break` statement.
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70 | * @returns {LoopContext|SwitchContext} A context for a `break` statement.
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71 | */
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72 | function getBreakContext(state, label) {
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73 | let context = state.breakContext;
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74 |
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75 | while (context) {
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76 | if (label ? context.label === label : context.breakable) {
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77 | return context;
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78 | }
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79 | context = context.upper;
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80 | }
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81 |
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82 | /* istanbul ignore next: foolproof (syntax error) */
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83 | return null;
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84 | }
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85 |
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86 | /**
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87 | * Gets a context for a `return` statement.
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88 | * @param {CodePathState} state A state to get.
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89 | * @returns {TryContext|CodePathState} A context for a `return` statement.
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90 | */
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91 | function getReturnContext(state) {
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92 | let context = state.tryContext;
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93 |
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94 | while (context) {
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95 | if (context.hasFinalizer && context.position !== "finally") {
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96 | return context;
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97 | }
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98 | context = context.upper;
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99 | }
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100 |
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101 | return state;
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102 | }
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103 |
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104 | /**
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105 | * Gets a context for a `throw` statement.
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106 | * @param {CodePathState} state A state to get.
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107 | * @returns {TryContext|CodePathState} A context for a `throw` statement.
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108 | */
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109 | function getThrowContext(state) {
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110 | let context = state.tryContext;
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111 |
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112 | while (context) {
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113 | if (context.position === "try" ||
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114 | (context.hasFinalizer && context.position === "catch")
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115 | ) {
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116 | return context;
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117 | }
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118 | context = context.upper;
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119 | }
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120 |
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121 | return state;
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122 | }
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123 |
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124 | /**
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125 | * Removes a given element from a given array.
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126 | * @param {any[]} xs An array to remove the specific element.
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127 | * @param {any} x An element to be removed.
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128 | * @returns {void}
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129 | */
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130 | function remove(xs, x) {
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131 | xs.splice(xs.indexOf(x), 1);
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132 | }
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133 |
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134 | /**
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135 | * Disconnect given segments.
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136 | *
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137 | * This is used in a process for switch statements.
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138 | * If there is the "default" chunk before other cases, the order is different
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139 | * between node's and running's.
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140 | * @param {CodePathSegment[]} prevSegments Forward segments to disconnect.
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141 | * @param {CodePathSegment[]} nextSegments Backward segments to disconnect.
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142 | * @returns {void}
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143 | */
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144 | function removeConnection(prevSegments, nextSegments) {
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145 | for (let i = 0; i < prevSegments.length; ++i) {
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146 | const prevSegment = prevSegments[i];
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147 | const nextSegment = nextSegments[i];
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148 |
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149 | remove(prevSegment.nextSegments, nextSegment);
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150 | remove(prevSegment.allNextSegments, nextSegment);
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151 | remove(nextSegment.prevSegments, prevSegment);
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152 | remove(nextSegment.allPrevSegments, prevSegment);
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153 | }
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154 | }
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155 |
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156 | /**
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157 | * Creates looping path.
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158 | * @param {CodePathState} state The instance.
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159 | * @param {CodePathSegment[]} unflattenedFromSegments Segments which are source.
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160 | * @param {CodePathSegment[]} unflattenedToSegments Segments which are destination.
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161 | * @returns {void}
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162 | */
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163 | function makeLooped(state, unflattenedFromSegments, unflattenedToSegments) {
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164 | const fromSegments = CodePathSegment.flattenUnusedSegments(unflattenedFromSegments);
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165 | const toSegments = CodePathSegment.flattenUnusedSegments(unflattenedToSegments);
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166 |
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167 | const end = Math.min(fromSegments.length, toSegments.length);
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168 |
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169 | for (let i = 0; i < end; ++i) {
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170 | const fromSegment = fromSegments[i];
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171 | const toSegment = toSegments[i];
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172 |
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173 | if (toSegment.reachable) {
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174 | fromSegment.nextSegments.push(toSegment);
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175 | }
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176 | if (fromSegment.reachable) {
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177 | toSegment.prevSegments.push(fromSegment);
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178 | }
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179 | fromSegment.allNextSegments.push(toSegment);
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180 | toSegment.allPrevSegments.push(fromSegment);
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181 |
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182 | if (toSegment.allPrevSegments.length >= 2) {
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183 | CodePathSegment.markPrevSegmentAsLooped(toSegment, fromSegment);
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184 | }
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185 |
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186 | state.notifyLooped(fromSegment, toSegment);
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187 | }
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188 | }
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189 |
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190 | /**
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191 | * Finalizes segments of `test` chunk of a ForStatement.
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192 | *
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193 | * - Adds `false` paths to paths which are leaving from the loop.
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194 | * - Sets `true` paths to paths which go to the body.
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195 | * @param {LoopContext} context A loop context to modify.
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196 | * @param {ChoiceContext} choiceContext A choice context of this loop.
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197 | * @param {CodePathSegment[]} head The current head paths.
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198 | * @returns {void}
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199 | */
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200 | function finalizeTestSegmentsOfFor(context, choiceContext, head) {
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201 | if (!choiceContext.processed) {
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202 | choiceContext.trueForkContext.add(head);
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203 | choiceContext.falseForkContext.add(head);
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204 | choiceContext.qqForkContext.add(head);
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205 | }
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206 |
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207 | if (context.test !== true) {
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208 | context.brokenForkContext.addAll(choiceContext.falseForkContext);
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209 | }
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210 | context.endOfTestSegments = choiceContext.trueForkContext.makeNext(0, -1);
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211 | }
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212 |
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213 | //------------------------------------------------------------------------------
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214 | // Public Interface
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215 | //------------------------------------------------------------------------------
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216 |
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217 | /**
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218 | * A class which manages state to analyze code paths.
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219 | */
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220 | class CodePathState {
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221 |
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222 | // eslint-disable-next-line jsdoc/require-description
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223 | /**
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224 | * @param {IdGenerator} idGenerator An id generator to generate id for code
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225 | * path segments.
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226 | * @param {Function} onLooped A callback function to notify looping.
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227 | */
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228 | constructor(idGenerator, onLooped) {
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229 | this.idGenerator = idGenerator;
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230 | this.notifyLooped = onLooped;
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231 | this.forkContext = ForkContext.newRoot(idGenerator);
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232 | this.choiceContext = null;
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233 | this.switchContext = null;
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234 | this.tryContext = null;
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235 | this.loopContext = null;
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236 | this.breakContext = null;
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237 | this.chainContext = null;
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238 |
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239 | this.currentSegments = [];
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240 | this.initialSegment = this.forkContext.head[0];
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241 |
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242 | // returnedSegments and thrownSegments push elements into finalSegments also.
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243 | const final = this.finalSegments = [];
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244 | const returned = this.returnedForkContext = [];
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245 | const thrown = this.thrownForkContext = [];
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246 |
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247 | returned.add = addToReturnedOrThrown.bind(null, returned, thrown, final);
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248 | thrown.add = addToReturnedOrThrown.bind(null, thrown, returned, final);
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249 | }
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250 |
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251 | /**
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252 | * The head segments.
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253 | * @type {CodePathSegment[]}
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254 | */
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255 | get headSegments() {
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256 | return this.forkContext.head;
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257 | }
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258 |
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259 | /**
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260 | * The parent forking context.
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261 | * This is used for the root of new forks.
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262 | * @type {ForkContext}
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263 | */
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264 | get parentForkContext() {
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265 | const current = this.forkContext;
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266 |
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267 | return current && current.upper;
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268 | }
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269 |
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270 | /**
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271 | * Creates and stacks new forking context.
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272 | * @param {boolean} forkLeavingPath A flag which shows being in a
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273 | * "finally" block.
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274 | * @returns {ForkContext} The created context.
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275 | */
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276 | pushForkContext(forkLeavingPath) {
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277 | this.forkContext = ForkContext.newEmpty(
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278 | this.forkContext,
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279 | forkLeavingPath
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280 | );
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281 |
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282 | return this.forkContext;
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283 | }
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284 |
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285 | /**
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286 | * Pops and merges the last forking context.
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287 | * @returns {ForkContext} The last context.
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288 | */
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289 | popForkContext() {
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290 | const lastContext = this.forkContext;
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291 |
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292 | this.forkContext = lastContext.upper;
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293 | this.forkContext.replaceHead(lastContext.makeNext(0, -1));
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294 |
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295 | return lastContext;
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296 | }
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297 |
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298 | /**
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299 | * Creates a new path.
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300 | * @returns {void}
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301 | */
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302 | forkPath() {
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303 | this.forkContext.add(this.parentForkContext.makeNext(-1, -1));
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304 | }
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305 |
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306 | /**
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307 | * Creates a bypass path.
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308 | * This is used for such as IfStatement which does not have "else" chunk.
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309 | * @returns {void}
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310 | */
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311 | forkBypassPath() {
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312 | this.forkContext.add(this.parentForkContext.head);
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313 | }
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314 |
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315 | //--------------------------------------------------------------------------
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316 | // ConditionalExpression, LogicalExpression, IfStatement
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317 | //--------------------------------------------------------------------------
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318 |
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319 | /**
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320 | * Creates a context for ConditionalExpression, LogicalExpression, AssignmentExpression (logical assignments only),
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321 | * IfStatement, WhileStatement, DoWhileStatement, or ForStatement.
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322 | *
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323 | * LogicalExpressions have cases that it goes different paths between the
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324 | * `true` case and the `false` case.
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325 | *
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326 | * For Example:
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327 | *
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328 | * if (a || b) {
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329 | * foo();
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330 | * } else {
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331 | * bar();
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332 | * }
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333 | *
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334 | * In this case, `b` is evaluated always in the code path of the `else`
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335 | * block, but it's not so in the code path of the `if` block.
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336 | * So there are 3 paths.
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337 | *
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338 | * a -> foo();
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339 | * a -> b -> foo();
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340 | * a -> b -> bar();
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341 | * @param {string} kind A kind string.
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342 | * If the new context is LogicalExpression's or AssignmentExpression's, this is `"&&"` or `"||"` or `"??"`.
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343 | * If it's IfStatement's or ConditionalExpression's, this is `"test"`.
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344 | * Otherwise, this is `"loop"`.
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345 | * @param {boolean} isForkingAsResult A flag that shows that goes different
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346 | * paths between `true` and `false`.
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347 | * @returns {void}
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348 | */
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349 | pushChoiceContext(kind, isForkingAsResult) {
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350 | this.choiceContext = {
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351 | upper: this.choiceContext,
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352 | kind,
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353 | isForkingAsResult,
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354 | trueForkContext: ForkContext.newEmpty(this.forkContext),
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355 | falseForkContext: ForkContext.newEmpty(this.forkContext),
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356 | qqForkContext: ForkContext.newEmpty(this.forkContext),
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357 | processed: false
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358 | };
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359 | }
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360 |
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361 | /**
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362 | * Pops the last choice context and finalizes it.
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363 | * @returns {ChoiceContext} The popped context.
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364 | */
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365 | popChoiceContext() {
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366 | const context = this.choiceContext;
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367 |
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368 | this.choiceContext = context.upper;
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369 |
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370 | const forkContext = this.forkContext;
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371 | const headSegments = forkContext.head;
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372 |
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373 | switch (context.kind) {
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374 | case "&&":
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375 | case "||":
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376 | case "??":
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377 |
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378 | /*
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379 | * If any result were not transferred from child contexts,
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380 | * this sets the head segments to both cases.
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381 | * The head segments are the path of the right-hand operand.
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382 | */
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383 | if (!context.processed) {
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384 | context.trueForkContext.add(headSegments);
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385 | context.falseForkContext.add(headSegments);
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386 | context.qqForkContext.add(headSegments);
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387 | }
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388 |
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389 | /*
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390 | * Transfers results to upper context if this context is in
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391 | * test chunk.
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392 | */
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393 | if (context.isForkingAsResult) {
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394 | const parentContext = this.choiceContext;
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395 |
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396 | parentContext.trueForkContext.addAll(context.trueForkContext);
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397 | parentContext.falseForkContext.addAll(context.falseForkContext);
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398 | parentContext.qqForkContext.addAll(context.qqForkContext);
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399 | parentContext.processed = true;
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400 |
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401 | return context;
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402 | }
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403 |
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404 | break;
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405 |
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406 | case "test":
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407 | if (!context.processed) {
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408 |
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409 | /*
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410 | * The head segments are the path of the `if` block here.
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411 | * Updates the `true` path with the end of the `if` block.
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412 | */
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413 | context.trueForkContext.clear();
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414 | context.trueForkContext.add(headSegments);
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415 | } else {
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416 |
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417 | /*
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418 | * The head segments are the path of the `else` block here.
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419 | * Updates the `false` path with the end of the `else`
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420 | * block.
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421 | */
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422 | context.falseForkContext.clear();
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423 | context.falseForkContext.add(headSegments);
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424 | }
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425 |
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426 | break;
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427 |
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428 | case "loop":
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429 |
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430 | /*
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431 | * Loops are addressed in popLoopContext().
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432 | * This is called from popLoopContext().
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433 | */
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434 | return context;
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435 |
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436 | /* istanbul ignore next */
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437 | default:
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438 | throw new Error("unreachable");
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439 | }
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440 |
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441 | // Merges all paths.
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442 | const prevForkContext = context.trueForkContext;
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443 |
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444 | prevForkContext.addAll(context.falseForkContext);
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445 | forkContext.replaceHead(prevForkContext.makeNext(0, -1));
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446 |
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447 | return context;
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448 | }
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449 |
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450 | /**
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451 | * Makes a code path segment of the right-hand operand of a logical
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452 | * expression.
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453 | * @returns {void}
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454 | */
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455 | makeLogicalRight() {
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456 | const context = this.choiceContext;
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457 | const forkContext = this.forkContext;
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458 |
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459 | if (context.processed) {
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460 |
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461 | /*
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462 | * This got segments already from the child choice context.
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463 | * Creates the next path from own true/false fork context.
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464 | */
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465 | let prevForkContext;
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466 |
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467 | switch (context.kind) {
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468 | case "&&": // if true then go to the right-hand side.
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469 | prevForkContext = context.trueForkContext;
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470 | break;
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471 | case "||": // if false then go to the right-hand side.
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472 | prevForkContext = context.falseForkContext;
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473 | break;
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474 | case "??": // Both true/false can short-circuit, so needs the third path to go to the right-hand side. That's qqForkContext.
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475 | prevForkContext = context.qqForkContext;
|
476 | break;
|
477 | default:
|
478 | throw new Error("unreachable");
|
479 | }
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480 |
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481 | forkContext.replaceHead(prevForkContext.makeNext(0, -1));
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482 | prevForkContext.clear();
|
483 | context.processed = false;
|
484 | } else {
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485 |
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486 | /*
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487 | * This did not get segments from the child choice context.
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488 | * So addresses the head segments.
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489 | * The head segments are the path of the left-hand operand.
|
490 | */
|
491 | switch (context.kind) {
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492 | case "&&": // the false path can short-circuit.
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493 | context.falseForkContext.add(forkContext.head);
|
494 | break;
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495 | case "||": // the true path can short-circuit.
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496 | context.trueForkContext.add(forkContext.head);
|
497 | break;
|
498 | case "??": // both can short-circuit.
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499 | context.trueForkContext.add(forkContext.head);
|
500 | context.falseForkContext.add(forkContext.head);
|
501 | break;
|
502 | default:
|
503 | throw new Error("unreachable");
|
504 | }
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505 |
|
506 | forkContext.replaceHead(forkContext.makeNext(-1, -1));
|
507 | }
|
508 | }
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509 |
|
510 | /**
|
511 | * Makes a code path segment of the `if` block.
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512 | * @returns {void}
|
513 | */
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514 | makeIfConsequent() {
|
515 | const context = this.choiceContext;
|
516 | const forkContext = this.forkContext;
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517 |
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518 | /*
|
519 | * If any result were not transferred from child contexts,
|
520 | * this sets the head segments to both cases.
|
521 | * The head segments are the path of the test expression.
|
522 | */
|
523 | if (!context.processed) {
|
524 | context.trueForkContext.add(forkContext.head);
|
525 | context.falseForkContext.add(forkContext.head);
|
526 | context.qqForkContext.add(forkContext.head);
|
527 | }
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528 |
|
529 | context.processed = false;
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530 |
|
531 | // Creates new path from the `true` case.
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532 | forkContext.replaceHead(
|
533 | context.trueForkContext.makeNext(0, -1)
|
534 | );
|
535 | }
|
536 |
|
537 | /**
|
538 | * Makes a code path segment of the `else` block.
|
539 | * @returns {void}
|
540 | */
|
541 | makeIfAlternate() {
|
542 | const context = this.choiceContext;
|
543 | const forkContext = this.forkContext;
|
544 |
|
545 | /*
|
546 | * The head segments are the path of the `if` block.
|
547 | * Updates the `true` path with the end of the `if` block.
|
548 | */
|
549 | context.trueForkContext.clear();
|
550 | context.trueForkContext.add(forkContext.head);
|
551 | context.processed = true;
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552 |
|
553 | // Creates new path from the `false` case.
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554 | forkContext.replaceHead(
|
555 | context.falseForkContext.makeNext(0, -1)
|
556 | );
|
557 | }
|
558 |
|
559 | //--------------------------------------------------------------------------
|
560 | // ChainExpression
|
561 | //--------------------------------------------------------------------------
|
562 |
|
563 | /**
|
564 | * Push a new `ChainExpression` context to the stack.
|
565 | * This method is called on entering to each `ChainExpression` node.
|
566 | * This context is used to count forking in the optional chain then merge them on the exiting from the `ChainExpression` node.
|
567 | * @returns {void}
|
568 | */
|
569 | pushChainContext() {
|
570 | this.chainContext = {
|
571 | upper: this.chainContext,
|
572 | countChoiceContexts: 0
|
573 | };
|
574 | }
|
575 |
|
576 | /**
|
577 | * Pop a `ChainExpression` context from the stack.
|
578 | * This method is called on exiting from each `ChainExpression` node.
|
579 | * This merges all forks of the last optional chaining.
|
580 | * @returns {void}
|
581 | */
|
582 | popChainContext() {
|
583 | const context = this.chainContext;
|
584 |
|
585 | this.chainContext = context.upper;
|
586 |
|
587 | // pop all choice contexts of this.
|
588 | for (let i = context.countChoiceContexts; i > 0; --i) {
|
589 | this.popChoiceContext();
|
590 | }
|
591 | }
|
592 |
|
593 | /**
|
594 | * Create a choice context for optional access.
|
595 | * This method is called on entering to each `(Call|Member)Expression[optional=true]` node.
|
596 | * This creates a choice context as similar to `LogicalExpression[operator="??"]` node.
|
597 | * @returns {void}
|
598 | */
|
599 | makeOptionalNode() {
|
600 | if (this.chainContext) {
|
601 | this.chainContext.countChoiceContexts += 1;
|
602 | this.pushChoiceContext("??", false);
|
603 | }
|
604 | }
|
605 |
|
606 | /**
|
607 | * Create a fork.
|
608 | * This method is called on entering to the `arguments|property` property of each `(Call|Member)Expression` node.
|
609 | * @returns {void}
|
610 | */
|
611 | makeOptionalRight() {
|
612 | if (this.chainContext) {
|
613 | this.makeLogicalRight();
|
614 | }
|
615 | }
|
616 |
|
617 | //--------------------------------------------------------------------------
|
618 | // SwitchStatement
|
619 | //--------------------------------------------------------------------------
|
620 |
|
621 | /**
|
622 | * Creates a context object of SwitchStatement and stacks it.
|
623 | * @param {boolean} hasCase `true` if the switch statement has one or more
|
624 | * case parts.
|
625 | * @param {string|null} label The label text.
|
626 | * @returns {void}
|
627 | */
|
628 | pushSwitchContext(hasCase, label) {
|
629 | this.switchContext = {
|
630 | upper: this.switchContext,
|
631 | hasCase,
|
632 | defaultSegments: null,
|
633 | defaultBodySegments: null,
|
634 | foundDefault: false,
|
635 | lastIsDefault: false,
|
636 | countForks: 0
|
637 | };
|
638 |
|
639 | this.pushBreakContext(true, label);
|
640 | }
|
641 |
|
642 | /**
|
643 | * Pops the last context of SwitchStatement and finalizes it.
|
644 | *
|
645 | * - Disposes all forking stack for `case` and `default`.
|
646 | * - Creates the next code path segment from `context.brokenForkContext`.
|
647 | * - If the last `SwitchCase` node is not a `default` part, creates a path
|
648 | * to the `default` body.
|
649 | * @returns {void}
|
650 | */
|
651 | popSwitchContext() {
|
652 | const context = this.switchContext;
|
653 |
|
654 | this.switchContext = context.upper;
|
655 |
|
656 | const forkContext = this.forkContext;
|
657 | const brokenForkContext = this.popBreakContext().brokenForkContext;
|
658 |
|
659 | if (context.countForks === 0) {
|
660 |
|
661 | /*
|
662 | * When there is only one `default` chunk and there is one or more
|
663 | * `break` statements, even if forks are nothing, it needs to merge
|
664 | * those.
|
665 | */
|
666 | if (!brokenForkContext.empty) {
|
667 | brokenForkContext.add(forkContext.makeNext(-1, -1));
|
668 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1));
|
669 | }
|
670 |
|
671 | return;
|
672 | }
|
673 |
|
674 | const lastSegments = forkContext.head;
|
675 |
|
676 | this.forkBypassPath();
|
677 | const lastCaseSegments = forkContext.head;
|
678 |
|
679 | /*
|
680 | * `brokenForkContext` is used to make the next segment.
|
681 | * It must add the last segment into `brokenForkContext`.
|
682 | */
|
683 | brokenForkContext.add(lastSegments);
|
684 |
|
685 | /*
|
686 | * A path which is failed in all case test should be connected to path
|
687 | * of `default` chunk.
|
688 | */
|
689 | if (!context.lastIsDefault) {
|
690 | if (context.defaultBodySegments) {
|
691 |
|
692 | /*
|
693 | * Remove a link from `default` label to its chunk.
|
694 | * It's false route.
|
695 | */
|
696 | removeConnection(context.defaultSegments, context.defaultBodySegments);
|
697 | makeLooped(this, lastCaseSegments, context.defaultBodySegments);
|
698 | } else {
|
699 |
|
700 | /*
|
701 | * It handles the last case body as broken if `default` chunk
|
702 | * does not exist.
|
703 | */
|
704 | brokenForkContext.add(lastCaseSegments);
|
705 | }
|
706 | }
|
707 |
|
708 | // Pops the segment context stack until the entry segment.
|
709 | for (let i = 0; i < context.countForks; ++i) {
|
710 | this.forkContext = this.forkContext.upper;
|
711 | }
|
712 |
|
713 | /*
|
714 | * Creates a path from all brokenForkContext paths.
|
715 | * This is a path after switch statement.
|
716 | */
|
717 | this.forkContext.replaceHead(brokenForkContext.makeNext(0, -1));
|
718 | }
|
719 |
|
720 | /**
|
721 | * Makes a code path segment for a `SwitchCase` node.
|
722 | * @param {boolean} isEmpty `true` if the body is empty.
|
723 | * @param {boolean} isDefault `true` if the body is the default case.
|
724 | * @returns {void}
|
725 | */
|
726 | makeSwitchCaseBody(isEmpty, isDefault) {
|
727 | const context = this.switchContext;
|
728 |
|
729 | if (!context.hasCase) {
|
730 | return;
|
731 | }
|
732 |
|
733 | /*
|
734 | * Merge forks.
|
735 | * The parent fork context has two segments.
|
736 | * Those are from the current case and the body of the previous case.
|
737 | */
|
738 | const parentForkContext = this.forkContext;
|
739 | const forkContext = this.pushForkContext();
|
740 |
|
741 | forkContext.add(parentForkContext.makeNext(0, -1));
|
742 |
|
743 | /*
|
744 | * Save `default` chunk info.
|
745 | * If the `default` label is not at the last, we must make a path from
|
746 | * the last `case` to the `default` chunk.
|
747 | */
|
748 | if (isDefault) {
|
749 | context.defaultSegments = parentForkContext.head;
|
750 | if (isEmpty) {
|
751 | context.foundDefault = true;
|
752 | } else {
|
753 | context.defaultBodySegments = forkContext.head;
|
754 | }
|
755 | } else {
|
756 | if (!isEmpty && context.foundDefault) {
|
757 | context.foundDefault = false;
|
758 | context.defaultBodySegments = forkContext.head;
|
759 | }
|
760 | }
|
761 |
|
762 | context.lastIsDefault = isDefault;
|
763 | context.countForks += 1;
|
764 | }
|
765 |
|
766 | //--------------------------------------------------------------------------
|
767 | // TryStatement
|
768 | //--------------------------------------------------------------------------
|
769 |
|
770 | /**
|
771 | * Creates a context object of TryStatement and stacks it.
|
772 | * @param {boolean} hasFinalizer `true` if the try statement has a
|
773 | * `finally` block.
|
774 | * @returns {void}
|
775 | */
|
776 | pushTryContext(hasFinalizer) {
|
777 | this.tryContext = {
|
778 | upper: this.tryContext,
|
779 | position: "try",
|
780 | hasFinalizer,
|
781 |
|
782 | returnedForkContext: hasFinalizer
|
783 | ? ForkContext.newEmpty(this.forkContext)
|
784 | : null,
|
785 |
|
786 | thrownForkContext: ForkContext.newEmpty(this.forkContext),
|
787 | lastOfTryIsReachable: false,
|
788 | lastOfCatchIsReachable: false
|
789 | };
|
790 | }
|
791 |
|
792 | /**
|
793 | * Pops the last context of TryStatement and finalizes it.
|
794 | * @returns {void}
|
795 | */
|
796 | popTryContext() {
|
797 | const context = this.tryContext;
|
798 |
|
799 | this.tryContext = context.upper;
|
800 |
|
801 | if (context.position === "catch") {
|
802 |
|
803 | // Merges two paths from the `try` block and `catch` block merely.
|
804 | this.popForkContext();
|
805 | return;
|
806 | }
|
807 |
|
808 | /*
|
809 | * The following process is executed only when there is the `finally`
|
810 | * block.
|
811 | */
|
812 |
|
813 | const returned = context.returnedForkContext;
|
814 | const thrown = context.thrownForkContext;
|
815 |
|
816 | if (returned.empty && thrown.empty) {
|
817 | return;
|
818 | }
|
819 |
|
820 | // Separate head to normal paths and leaving paths.
|
821 | const headSegments = this.forkContext.head;
|
822 |
|
823 | this.forkContext = this.forkContext.upper;
|
824 | const normalSegments = headSegments.slice(0, headSegments.length / 2 | 0);
|
825 | const leavingSegments = headSegments.slice(headSegments.length / 2 | 0);
|
826 |
|
827 | // Forwards the leaving path to upper contexts.
|
828 | if (!returned.empty) {
|
829 | getReturnContext(this).returnedForkContext.add(leavingSegments);
|
830 | }
|
831 | if (!thrown.empty) {
|
832 | getThrowContext(this).thrownForkContext.add(leavingSegments);
|
833 | }
|
834 |
|
835 | // Sets the normal path as the next.
|
836 | this.forkContext.replaceHead(normalSegments);
|
837 |
|
838 | /*
|
839 | * If both paths of the `try` block and the `catch` block are
|
840 | * unreachable, the next path becomes unreachable as well.
|
841 | */
|
842 | if (!context.lastOfTryIsReachable && !context.lastOfCatchIsReachable) {
|
843 | this.forkContext.makeUnreachable();
|
844 | }
|
845 | }
|
846 |
|
847 | /**
|
848 | * Makes a code path segment for a `catch` block.
|
849 | * @returns {void}
|
850 | */
|
851 | makeCatchBlock() {
|
852 | const context = this.tryContext;
|
853 | const forkContext = this.forkContext;
|
854 | const thrown = context.thrownForkContext;
|
855 |
|
856 | // Update state.
|
857 | context.position = "catch";
|
858 | context.thrownForkContext = ForkContext.newEmpty(forkContext);
|
859 | context.lastOfTryIsReachable = forkContext.reachable;
|
860 |
|
861 | // Merge thrown paths.
|
862 | thrown.add(forkContext.head);
|
863 | const thrownSegments = thrown.makeNext(0, -1);
|
864 |
|
865 | // Fork to a bypass and the merged thrown path.
|
866 | this.pushForkContext();
|
867 | this.forkBypassPath();
|
868 | this.forkContext.add(thrownSegments);
|
869 | }
|
870 |
|
871 | /**
|
872 | * Makes a code path segment for a `finally` block.
|
873 | *
|
874 | * In the `finally` block, parallel paths are created. The parallel paths
|
875 | * are used as leaving-paths. The leaving-paths are paths from `return`
|
876 | * statements and `throw` statements in a `try` block or a `catch` block.
|
877 | * @returns {void}
|
878 | */
|
879 | makeFinallyBlock() {
|
880 | const context = this.tryContext;
|
881 | let forkContext = this.forkContext;
|
882 | const returned = context.returnedForkContext;
|
883 | const thrown = context.thrownForkContext;
|
884 | const headOfLeavingSegments = forkContext.head;
|
885 |
|
886 | // Update state.
|
887 | if (context.position === "catch") {
|
888 |
|
889 | // Merges two paths from the `try` block and `catch` block.
|
890 | this.popForkContext();
|
891 | forkContext = this.forkContext;
|
892 |
|
893 | context.lastOfCatchIsReachable = forkContext.reachable;
|
894 | } else {
|
895 | context.lastOfTryIsReachable = forkContext.reachable;
|
896 | }
|
897 | context.position = "finally";
|
898 |
|
899 | if (returned.empty && thrown.empty) {
|
900 |
|
901 | // This path does not leave.
|
902 | return;
|
903 | }
|
904 |
|
905 | /*
|
906 | * Create a parallel segment from merging returned and thrown.
|
907 | * This segment will leave at the end of this finally block.
|
908 | */
|
909 | const segments = forkContext.makeNext(-1, -1);
|
910 |
|
911 | for (let i = 0; i < forkContext.count; ++i) {
|
912 | const prevSegsOfLeavingSegment = [headOfLeavingSegments[i]];
|
913 |
|
914 | for (let j = 0; j < returned.segmentsList.length; ++j) {
|
915 | prevSegsOfLeavingSegment.push(returned.segmentsList[j][i]);
|
916 | }
|
917 | for (let j = 0; j < thrown.segmentsList.length; ++j) {
|
918 | prevSegsOfLeavingSegment.push(thrown.segmentsList[j][i]);
|
919 | }
|
920 |
|
921 | segments.push(
|
922 | CodePathSegment.newNext(
|
923 | this.idGenerator.next(),
|
924 | prevSegsOfLeavingSegment
|
925 | )
|
926 | );
|
927 | }
|
928 |
|
929 | this.pushForkContext(true);
|
930 | this.forkContext.add(segments);
|
931 | }
|
932 |
|
933 | /**
|
934 | * Makes a code path segment from the first throwable node to the `catch`
|
935 | * block or the `finally` block.
|
936 | * @returns {void}
|
937 | */
|
938 | makeFirstThrowablePathInTryBlock() {
|
939 | const forkContext = this.forkContext;
|
940 |
|
941 | if (!forkContext.reachable) {
|
942 | return;
|
943 | }
|
944 |
|
945 | const context = getThrowContext(this);
|
946 |
|
947 | if (context === this ||
|
948 | context.position !== "try" ||
|
949 | !context.thrownForkContext.empty
|
950 | ) {
|
951 | return;
|
952 | }
|
953 |
|
954 | context.thrownForkContext.add(forkContext.head);
|
955 | forkContext.replaceHead(forkContext.makeNext(-1, -1));
|
956 | }
|
957 |
|
958 | //--------------------------------------------------------------------------
|
959 | // Loop Statements
|
960 | //--------------------------------------------------------------------------
|
961 |
|
962 | /**
|
963 | * Creates a context object of a loop statement and stacks it.
|
964 | * @param {string} type The type of the node which was triggered. One of
|
965 | * `WhileStatement`, `DoWhileStatement`, `ForStatement`, `ForInStatement`,
|
966 | * and `ForStatement`.
|
967 | * @param {string|null} label A label of the node which was triggered.
|
968 | * @returns {void}
|
969 | */
|
970 | pushLoopContext(type, label) {
|
971 | const forkContext = this.forkContext;
|
972 | const breakContext = this.pushBreakContext(true, label);
|
973 |
|
974 | switch (type) {
|
975 | case "WhileStatement":
|
976 | this.pushChoiceContext("loop", false);
|
977 | this.loopContext = {
|
978 | upper: this.loopContext,
|
979 | type,
|
980 | label,
|
981 | test: void 0,
|
982 | continueDestSegments: null,
|
983 | brokenForkContext: breakContext.brokenForkContext
|
984 | };
|
985 | break;
|
986 |
|
987 | case "DoWhileStatement":
|
988 | this.pushChoiceContext("loop", false);
|
989 | this.loopContext = {
|
990 | upper: this.loopContext,
|
991 | type,
|
992 | label,
|
993 | test: void 0,
|
994 | entrySegments: null,
|
995 | continueForkContext: ForkContext.newEmpty(forkContext),
|
996 | brokenForkContext: breakContext.brokenForkContext
|
997 | };
|
998 | break;
|
999 |
|
1000 | case "ForStatement":
|
1001 | this.pushChoiceContext("loop", false);
|
1002 | this.loopContext = {
|
1003 | upper: this.loopContext,
|
1004 | type,
|
1005 | label,
|
1006 | test: void 0,
|
1007 | endOfInitSegments: null,
|
1008 | testSegments: null,
|
1009 | endOfTestSegments: null,
|
1010 | updateSegments: null,
|
1011 | endOfUpdateSegments: null,
|
1012 | continueDestSegments: null,
|
1013 | brokenForkContext: breakContext.brokenForkContext
|
1014 | };
|
1015 | break;
|
1016 |
|
1017 | case "ForInStatement":
|
1018 | case "ForOfStatement":
|
1019 | this.loopContext = {
|
1020 | upper: this.loopContext,
|
1021 | type,
|
1022 | label,
|
1023 | prevSegments: null,
|
1024 | leftSegments: null,
|
1025 | endOfLeftSegments: null,
|
1026 | continueDestSegments: null,
|
1027 | brokenForkContext: breakContext.brokenForkContext
|
1028 | };
|
1029 | break;
|
1030 |
|
1031 | /* istanbul ignore next */
|
1032 | default:
|
1033 | throw new Error(`unknown type: "${type}"`);
|
1034 | }
|
1035 | }
|
1036 |
|
1037 | /**
|
1038 | * Pops the last context of a loop statement and finalizes it.
|
1039 | * @returns {void}
|
1040 | */
|
1041 | popLoopContext() {
|
1042 | const context = this.loopContext;
|
1043 |
|
1044 | this.loopContext = context.upper;
|
1045 |
|
1046 | const forkContext = this.forkContext;
|
1047 | const brokenForkContext = this.popBreakContext().brokenForkContext;
|
1048 |
|
1049 | // Creates a looped path.
|
1050 | switch (context.type) {
|
1051 | case "WhileStatement":
|
1052 | case "ForStatement":
|
1053 | this.popChoiceContext();
|
1054 | makeLooped(
|
1055 | this,
|
1056 | forkContext.head,
|
1057 | context.continueDestSegments
|
1058 | );
|
1059 | break;
|
1060 |
|
1061 | case "DoWhileStatement": {
|
1062 | const choiceContext = this.popChoiceContext();
|
1063 |
|
1064 | if (!choiceContext.processed) {
|
1065 | choiceContext.trueForkContext.add(forkContext.head);
|
1066 | choiceContext.falseForkContext.add(forkContext.head);
|
1067 | }
|
1068 | if (context.test !== true) {
|
1069 | brokenForkContext.addAll(choiceContext.falseForkContext);
|
1070 | }
|
1071 |
|
1072 | // `true` paths go to looping.
|
1073 | const segmentsList = choiceContext.trueForkContext.segmentsList;
|
1074 |
|
1075 | for (let i = 0; i < segmentsList.length; ++i) {
|
1076 | makeLooped(
|
1077 | this,
|
1078 | segmentsList[i],
|
1079 | context.entrySegments
|
1080 | );
|
1081 | }
|
1082 | break;
|
1083 | }
|
1084 |
|
1085 | case "ForInStatement":
|
1086 | case "ForOfStatement":
|
1087 | brokenForkContext.add(forkContext.head);
|
1088 | makeLooped(
|
1089 | this,
|
1090 | forkContext.head,
|
1091 | context.leftSegments
|
1092 | );
|
1093 | break;
|
1094 |
|
1095 | /* istanbul ignore next */
|
1096 | default:
|
1097 | throw new Error("unreachable");
|
1098 | }
|
1099 |
|
1100 | // Go next.
|
1101 | if (brokenForkContext.empty) {
|
1102 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1));
|
1103 | } else {
|
1104 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1));
|
1105 | }
|
1106 | }
|
1107 |
|
1108 | /**
|
1109 | * Makes a code path segment for the test part of a WhileStatement.
|
1110 | * @param {boolean|undefined} test The test value (only when constant).
|
1111 | * @returns {void}
|
1112 | */
|
1113 | makeWhileTest(test) {
|
1114 | const context = this.loopContext;
|
1115 | const forkContext = this.forkContext;
|
1116 | const testSegments = forkContext.makeNext(0, -1);
|
1117 |
|
1118 | // Update state.
|
1119 | context.test = test;
|
1120 | context.continueDestSegments = testSegments;
|
1121 | forkContext.replaceHead(testSegments);
|
1122 | }
|
1123 |
|
1124 | /**
|
1125 | * Makes a code path segment for the body part of a WhileStatement.
|
1126 | * @returns {void}
|
1127 | */
|
1128 | makeWhileBody() {
|
1129 | const context = this.loopContext;
|
1130 | const choiceContext = this.choiceContext;
|
1131 | const forkContext = this.forkContext;
|
1132 |
|
1133 | if (!choiceContext.processed) {
|
1134 | choiceContext.trueForkContext.add(forkContext.head);
|
1135 | choiceContext.falseForkContext.add(forkContext.head);
|
1136 | }
|
1137 |
|
1138 | // Update state.
|
1139 | if (context.test !== true) {
|
1140 | context.brokenForkContext.addAll(choiceContext.falseForkContext);
|
1141 | }
|
1142 | forkContext.replaceHead(choiceContext.trueForkContext.makeNext(0, -1));
|
1143 | }
|
1144 |
|
1145 | /**
|
1146 | * Makes a code path segment for the body part of a DoWhileStatement.
|
1147 | * @returns {void}
|
1148 | */
|
1149 | makeDoWhileBody() {
|
1150 | const context = this.loopContext;
|
1151 | const forkContext = this.forkContext;
|
1152 | const bodySegments = forkContext.makeNext(-1, -1);
|
1153 |
|
1154 | // Update state.
|
1155 | context.entrySegments = bodySegments;
|
1156 | forkContext.replaceHead(bodySegments);
|
1157 | }
|
1158 |
|
1159 | /**
|
1160 | * Makes a code path segment for the test part of a DoWhileStatement.
|
1161 | * @param {boolean|undefined} test The test value (only when constant).
|
1162 | * @returns {void}
|
1163 | */
|
1164 | makeDoWhileTest(test) {
|
1165 | const context = this.loopContext;
|
1166 | const forkContext = this.forkContext;
|
1167 |
|
1168 | context.test = test;
|
1169 |
|
1170 | // Creates paths of `continue` statements.
|
1171 | if (!context.continueForkContext.empty) {
|
1172 | context.continueForkContext.add(forkContext.head);
|
1173 | const testSegments = context.continueForkContext.makeNext(0, -1);
|
1174 |
|
1175 | forkContext.replaceHead(testSegments);
|
1176 | }
|
1177 | }
|
1178 |
|
1179 | /**
|
1180 | * Makes a code path segment for the test part of a ForStatement.
|
1181 | * @param {boolean|undefined} test The test value (only when constant).
|
1182 | * @returns {void}
|
1183 | */
|
1184 | makeForTest(test) {
|
1185 | const context = this.loopContext;
|
1186 | const forkContext = this.forkContext;
|
1187 | const endOfInitSegments = forkContext.head;
|
1188 | const testSegments = forkContext.makeNext(-1, -1);
|
1189 |
|
1190 | // Update state.
|
1191 | context.test = test;
|
1192 | context.endOfInitSegments = endOfInitSegments;
|
1193 | context.continueDestSegments = context.testSegments = testSegments;
|
1194 | forkContext.replaceHead(testSegments);
|
1195 | }
|
1196 |
|
1197 | /**
|
1198 | * Makes a code path segment for the update part of a ForStatement.
|
1199 | * @returns {void}
|
1200 | */
|
1201 | makeForUpdate() {
|
1202 | const context = this.loopContext;
|
1203 | const choiceContext = this.choiceContext;
|
1204 | const forkContext = this.forkContext;
|
1205 |
|
1206 | // Make the next paths of the test.
|
1207 | if (context.testSegments) {
|
1208 | finalizeTestSegmentsOfFor(
|
1209 | context,
|
1210 | choiceContext,
|
1211 | forkContext.head
|
1212 | );
|
1213 | } else {
|
1214 | context.endOfInitSegments = forkContext.head;
|
1215 | }
|
1216 |
|
1217 | // Update state.
|
1218 | const updateSegments = forkContext.makeDisconnected(-1, -1);
|
1219 |
|
1220 | context.continueDestSegments = context.updateSegments = updateSegments;
|
1221 | forkContext.replaceHead(updateSegments);
|
1222 | }
|
1223 |
|
1224 | /**
|
1225 | * Makes a code path segment for the body part of a ForStatement.
|
1226 | * @returns {void}
|
1227 | */
|
1228 | makeForBody() {
|
1229 | const context = this.loopContext;
|
1230 | const choiceContext = this.choiceContext;
|
1231 | const forkContext = this.forkContext;
|
1232 |
|
1233 | // Update state.
|
1234 | if (context.updateSegments) {
|
1235 | context.endOfUpdateSegments = forkContext.head;
|
1236 |
|
1237 | // `update` -> `test`
|
1238 | if (context.testSegments) {
|
1239 | makeLooped(
|
1240 | this,
|
1241 | context.endOfUpdateSegments,
|
1242 | context.testSegments
|
1243 | );
|
1244 | }
|
1245 | } else if (context.testSegments) {
|
1246 | finalizeTestSegmentsOfFor(
|
1247 | context,
|
1248 | choiceContext,
|
1249 | forkContext.head
|
1250 | );
|
1251 | } else {
|
1252 | context.endOfInitSegments = forkContext.head;
|
1253 | }
|
1254 |
|
1255 | let bodySegments = context.endOfTestSegments;
|
1256 |
|
1257 | if (!bodySegments) {
|
1258 |
|
1259 | /*
|
1260 | * If there is not the `test` part, the `body` path comes from the
|
1261 | * `init` part and the `update` part.
|
1262 | */
|
1263 | const prevForkContext = ForkContext.newEmpty(forkContext);
|
1264 |
|
1265 | prevForkContext.add(context.endOfInitSegments);
|
1266 | if (context.endOfUpdateSegments) {
|
1267 | prevForkContext.add(context.endOfUpdateSegments);
|
1268 | }
|
1269 |
|
1270 | bodySegments = prevForkContext.makeNext(0, -1);
|
1271 | }
|
1272 | context.continueDestSegments = context.continueDestSegments || bodySegments;
|
1273 | forkContext.replaceHead(bodySegments);
|
1274 | }
|
1275 |
|
1276 | /**
|
1277 | * Makes a code path segment for the left part of a ForInStatement and a
|
1278 | * ForOfStatement.
|
1279 | * @returns {void}
|
1280 | */
|
1281 | makeForInOfLeft() {
|
1282 | const context = this.loopContext;
|
1283 | const forkContext = this.forkContext;
|
1284 | const leftSegments = forkContext.makeDisconnected(-1, -1);
|
1285 |
|
1286 | // Update state.
|
1287 | context.prevSegments = forkContext.head;
|
1288 | context.leftSegments = context.continueDestSegments = leftSegments;
|
1289 | forkContext.replaceHead(leftSegments);
|
1290 | }
|
1291 |
|
1292 | /**
|
1293 | * Makes a code path segment for the right part of a ForInStatement and a
|
1294 | * ForOfStatement.
|
1295 | * @returns {void}
|
1296 | */
|
1297 | makeForInOfRight() {
|
1298 | const context = this.loopContext;
|
1299 | const forkContext = this.forkContext;
|
1300 | const temp = ForkContext.newEmpty(forkContext);
|
1301 |
|
1302 | temp.add(context.prevSegments);
|
1303 | const rightSegments = temp.makeNext(-1, -1);
|
1304 |
|
1305 | // Update state.
|
1306 | context.endOfLeftSegments = forkContext.head;
|
1307 | forkContext.replaceHead(rightSegments);
|
1308 | }
|
1309 |
|
1310 | /**
|
1311 | * Makes a code path segment for the body part of a ForInStatement and a
|
1312 | * ForOfStatement.
|
1313 | * @returns {void}
|
1314 | */
|
1315 | makeForInOfBody() {
|
1316 | const context = this.loopContext;
|
1317 | const forkContext = this.forkContext;
|
1318 | const temp = ForkContext.newEmpty(forkContext);
|
1319 |
|
1320 | temp.add(context.endOfLeftSegments);
|
1321 | const bodySegments = temp.makeNext(-1, -1);
|
1322 |
|
1323 | // Make a path: `right` -> `left`.
|
1324 | makeLooped(this, forkContext.head, context.leftSegments);
|
1325 |
|
1326 | // Update state.
|
1327 | context.brokenForkContext.add(forkContext.head);
|
1328 | forkContext.replaceHead(bodySegments);
|
1329 | }
|
1330 |
|
1331 | //--------------------------------------------------------------------------
|
1332 | // Control Statements
|
1333 | //--------------------------------------------------------------------------
|
1334 |
|
1335 | /**
|
1336 | * Creates new context for BreakStatement.
|
1337 | * @param {boolean} breakable The flag to indicate it can break by
|
1338 | * an unlabeled BreakStatement.
|
1339 | * @param {string|null} label The label of this context.
|
1340 | * @returns {Object} The new context.
|
1341 | */
|
1342 | pushBreakContext(breakable, label) {
|
1343 | this.breakContext = {
|
1344 | upper: this.breakContext,
|
1345 | breakable,
|
1346 | label,
|
1347 | brokenForkContext: ForkContext.newEmpty(this.forkContext)
|
1348 | };
|
1349 | return this.breakContext;
|
1350 | }
|
1351 |
|
1352 | /**
|
1353 | * Removes the top item of the break context stack.
|
1354 | * @returns {Object} The removed context.
|
1355 | */
|
1356 | popBreakContext() {
|
1357 | const context = this.breakContext;
|
1358 | const forkContext = this.forkContext;
|
1359 |
|
1360 | this.breakContext = context.upper;
|
1361 |
|
1362 | // Process this context here for other than switches and loops.
|
1363 | if (!context.breakable) {
|
1364 | const brokenForkContext = context.brokenForkContext;
|
1365 |
|
1366 | if (!brokenForkContext.empty) {
|
1367 | brokenForkContext.add(forkContext.head);
|
1368 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1));
|
1369 | }
|
1370 | }
|
1371 |
|
1372 | return context;
|
1373 | }
|
1374 |
|
1375 | /**
|
1376 | * Makes a path for a `break` statement.
|
1377 | *
|
1378 | * It registers the head segment to a context of `break`.
|
1379 | * It makes new unreachable segment, then it set the head with the segment.
|
1380 | * @param {string} label A label of the break statement.
|
1381 | * @returns {void}
|
1382 | */
|
1383 | makeBreak(label) {
|
1384 | const forkContext = this.forkContext;
|
1385 |
|
1386 | if (!forkContext.reachable) {
|
1387 | return;
|
1388 | }
|
1389 |
|
1390 | const context = getBreakContext(this, label);
|
1391 |
|
1392 | /* istanbul ignore else: foolproof (syntax error) */
|
1393 | if (context) {
|
1394 | context.brokenForkContext.add(forkContext.head);
|
1395 | }
|
1396 |
|
1397 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1));
|
1398 | }
|
1399 |
|
1400 | /**
|
1401 | * Makes a path for a `continue` statement.
|
1402 | *
|
1403 | * It makes a looping path.
|
1404 | * It makes new unreachable segment, then it set the head with the segment.
|
1405 | * @param {string} label A label of the continue statement.
|
1406 | * @returns {void}
|
1407 | */
|
1408 | makeContinue(label) {
|
1409 | const forkContext = this.forkContext;
|
1410 |
|
1411 | if (!forkContext.reachable) {
|
1412 | return;
|
1413 | }
|
1414 |
|
1415 | const context = getContinueContext(this, label);
|
1416 |
|
1417 | /* istanbul ignore else: foolproof (syntax error) */
|
1418 | if (context) {
|
1419 | if (context.continueDestSegments) {
|
1420 | makeLooped(this, forkContext.head, context.continueDestSegments);
|
1421 |
|
1422 | // If the context is a for-in/of loop, this effects a break also.
|
1423 | if (context.type === "ForInStatement" ||
|
1424 | context.type === "ForOfStatement"
|
1425 | ) {
|
1426 | context.brokenForkContext.add(forkContext.head);
|
1427 | }
|
1428 | } else {
|
1429 | context.continueForkContext.add(forkContext.head);
|
1430 | }
|
1431 | }
|
1432 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1));
|
1433 | }
|
1434 |
|
1435 | /**
|
1436 | * Makes a path for a `return` statement.
|
1437 | *
|
1438 | * It registers the head segment to a context of `return`.
|
1439 | * It makes new unreachable segment, then it set the head with the segment.
|
1440 | * @returns {void}
|
1441 | */
|
1442 | makeReturn() {
|
1443 | const forkContext = this.forkContext;
|
1444 |
|
1445 | if (forkContext.reachable) {
|
1446 | getReturnContext(this).returnedForkContext.add(forkContext.head);
|
1447 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1));
|
1448 | }
|
1449 | }
|
1450 |
|
1451 | /**
|
1452 | * Makes a path for a `throw` statement.
|
1453 | *
|
1454 | * It registers the head segment to a context of `throw`.
|
1455 | * It makes new unreachable segment, then it set the head with the segment.
|
1456 | * @returns {void}
|
1457 | */
|
1458 | makeThrow() {
|
1459 | const forkContext = this.forkContext;
|
1460 |
|
1461 | if (forkContext.reachable) {
|
1462 | getThrowContext(this).thrownForkContext.add(forkContext.head);
|
1463 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1));
|
1464 | }
|
1465 | }
|
1466 |
|
1467 | /**
|
1468 | * Makes the final path.
|
1469 | * @returns {void}
|
1470 | */
|
1471 | makeFinal() {
|
1472 | const segments = this.currentSegments;
|
1473 |
|
1474 | if (segments.length > 0 && segments[0].reachable) {
|
1475 | this.returnedForkContext.add(segments);
|
1476 | }
|
1477 | }
|
1478 | }
|
1479 |
|
1480 | module.exports = CodePathState;
|