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							107 lines
						
					
					
						
							3.2 KiB
						
					
					
				
			
		
		
	
	
							107 lines
						
					
					
						
							3.2 KiB
						
					
					
				function _typeof(obj) { 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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 | 
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import { encodeNode } from "@webassemblyjs/wasm-gen"; | 
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import { overrideBytesInBuffer } from "@webassemblyjs/helper-buffer"; | 
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import constants from "@webassemblyjs/helper-wasm-bytecode"; | 
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import * as t from "@webassemblyjs/ast"; | 
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 | 
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function findLastSection(ast, forSection) { | 
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  var targetSectionId = constants.sections[forSection]; // $FlowIgnore: metadata can not be empty | 
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 | 
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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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 | 
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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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 | 
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    if (section.section === "custom") { | 
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      continue; | 
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    } | 
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 | 
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    var sectionId = constants.sections[section.section]; | 
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 | 
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    if (targetSectionId > lastId && targetSectionId < sectionId) { | 
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      return lastSection; | 
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    } | 
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 | 
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    lastId = sectionId; | 
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    lastSection = section; | 
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  } | 
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 | 
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  return lastSection; | 
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} | 
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 | 
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export 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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 | 
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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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 | 
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 | 
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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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 | 
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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 = encodeNode(sectionMetadata); | 
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  uint8Buffer = overrideBytesInBuffer(uint8Buffer, start - 1, end, sectionBytes); // Add section into the AST for later lookups | 
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 | 
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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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 | 
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 | 
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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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 | 
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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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} |