123 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
"use strict";
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Object.defineProperty(exports, "__esModule", {
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  value: true
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});
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exports.createEmptySection = createEmptySection;
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var _wasmGen = require("@webassemblyjs/wasm-gen");
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var _helperBuffer = require("@webassemblyjs/helper-buffer");
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var _helperWasmBytecode = _interopRequireDefault(require("@webassemblyjs/helper-wasm-bytecode"));
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var t = _interopRequireWildcard(require("@webassemblyjs/ast"));
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function _getRequireWildcardCache(nodeInterop) { if (typeof WeakMap !== "function") return null; var cacheBabelInterop = new WeakMap(); var cacheNodeInterop = new WeakMap(); return (_getRequireWildcardCache = function _getRequireWildcardCache(nodeInterop) { return nodeInterop ? cacheNodeInterop : cacheBabelInterop; })(nodeInterop); }
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function _interopRequireWildcard(obj, nodeInterop) { if (!nodeInterop && obj && obj.__esModule) { return obj; } if (obj === null || _typeof(obj) !== "object" && typeof obj !== "function") { return { "default": obj }; } var cache = _getRequireWildcardCache(nodeInterop); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj["default"] = obj; if (cache) { cache.set(obj, newObj); } return newObj; }
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
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function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
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function findLastSection(ast, forSection) {
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  var targetSectionId = _helperWasmBytecode["default"].sections[forSection]; // $FlowIgnore: metadata can not be empty
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  var moduleSections = ast.body[0].metadata.sections;
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  var lastSection;
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  var lastId = 0;
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  for (var i = 0, len = moduleSections.length; i < len; i++) {
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    var section = moduleSections[i]; // Ignore custom section since they can actually occur everywhere
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    if (section.section === "custom") {
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      continue;
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    }
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    var sectionId = _helperWasmBytecode["default"].sections[section.section];
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    if (targetSectionId > lastId && targetSectionId < sectionId) {
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      return lastSection;
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    }
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    lastId = sectionId;
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    lastSection = section;
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  }
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  return lastSection;
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}
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function createEmptySection(ast, uint8Buffer, section) {
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  // previous section after which we are going to insert our section
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  var lastSection = findLastSection(ast, section);
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  var start, end;
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  /**
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   * It's the first section
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   */
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  if (lastSection == null || lastSection.section === "custom") {
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    start = 8
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    /* wasm header size */
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    ;
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    end = start;
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  } else {
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    start = lastSection.startOffset + lastSection.size.value + 1;
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    end = start;
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  } // section id
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  start += 1;
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  var sizeStartLoc = {
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    line: -1,
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    column: start
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  };
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  var sizeEndLoc = {
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    line: -1,
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    column: start + 1
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  }; // 1 byte for the empty vector
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  var size = t.withLoc(t.numberLiteralFromRaw(1), sizeEndLoc, sizeStartLoc);
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  var vectorOfSizeStartLoc = {
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    line: -1,
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    column: sizeEndLoc.column
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  };
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  var vectorOfSizeEndLoc = {
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    line: -1,
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    column: sizeEndLoc.column + 1
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  };
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  var vectorOfSize = t.withLoc(t.numberLiteralFromRaw(0), vectorOfSizeEndLoc, vectorOfSizeStartLoc);
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  var sectionMetadata = t.sectionMetadata(section, start, size, vectorOfSize);
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  var sectionBytes = (0, _wasmGen.encodeNode)(sectionMetadata);
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  uint8Buffer = (0, _helperBuffer.overrideBytesInBuffer)(uint8Buffer, start - 1, end, sectionBytes); // Add section into the AST for later lookups
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  if (_typeof(ast.body[0].metadata) === "object") {
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    // $FlowIgnore: metadata can not be empty
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    ast.body[0].metadata.sections.push(sectionMetadata);
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    t.sortSectionMetadata(ast.body[0]);
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  }
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  /**
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   * Update AST
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   */
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  // Once we hit our section every that is after needs to be shifted by the delta
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  var deltaBytes = +sectionBytes.length;
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  var encounteredSection = false;
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  t.traverse(ast, {
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    SectionMetadata: function SectionMetadata(path) {
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      if (path.node.section === section) {
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        encounteredSection = true;
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        return;
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      }
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      if (encounteredSection === true) {
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        t.shiftSection(ast, path.node, deltaBytes);
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      }
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    }
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  });
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  return {
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    uint8Buffer: uint8Buffer,
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    sectionMetadata: sectionMetadata
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  };
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} |